Title:

Belt sander

Document Type and Number:

United States Patent 7410412

Abstract:

A belt sander is disclosed that may include a sanding assembly having a first roller and a second roller, the sanding assembly being configured to receive a sanding belt around the first roller and the second roller to define a sanding surface therebetweeen. The belt sander may include a motor operationally coupled to the sanding assembly and opposite the sanding surface, the motor being configured to rotate at least the first roller and thereby rotate the sanding belt around the first roller and the second roller, as well as a handgrip formed around at least a portion of the motor and substantially encasing the motor.

Inventors:

Wall, Daniel P. (Humboldt, TN, US)
Leasure, Jeremy D. (Jackson, TN, US)
Carroll, Craig A. (Milan, TN, US)
Jones, Julie L. (Jackson, TN, US)
Weston, Jeffrey D. (Jackson, TN, US)
Mooty, Thomas A. (Greenwood, MS, US)
Nichols Jr., James P. (Jackson, TN, US)
Schnell, John W. (Anderson, SC, US)

Plaque It!

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. 119 to U.S. Provisional Application 60/645,632, filed Jan, 21, 2005, and titled “IMPROVED BELT TRACKING MECHANISM FOR BELT SANDER.” This application also claims priority under 35 U.S.C. 119 to U.S. Provisional Application 60/757,818, filed Jan. 10, 2006, and titled “BELT SANDER.” This application also claims priority under 35 U.S.C. 120 to, and is a continuation-in-part of, U.S. application Ser. No. 11/089,447, filed Mar. 24, 2005 now U.S. Pat. No. 7,235,005, and titled, “BELT SANDER.” The above-identified applications are incorporated by reference in their entirety.

Claims:

What is claimed is:

1. A belt sander comprising: a sanding assembly having a first roller and a second roller, the sanding assembly being configured to receive a sanding belt around the first roller and the second roller to define a sanding surface therebetweeen; a motor operationally coupled to the sanding assembly with a longitudinal rotational axis thereof being oriented in a direction substantially perpendicular to the first roller and the second roller, the motor is configured to rotate at least the first roller and thereby rotate the sanding belt around the first roller and the second roller; and a handgrip formed around at least a portion of the motor and substantially encasing the motor between the handgrip and the sanding assembly, the handgrip including a convex surface having a longitudinal portion extending substantially in a same direction as the longitudinal rotational axis of the motor.

2. The belt sander of claim 1 wherein a center of gravity of the belt sander is substantially centered over the sanding assembly.

3. The belt sander of claim 1 wherein the motor is included within a three-dimensional area defined by a perimeter of the sanding assembly and extending in a direction of the motor.

4. The belt sander of claim 1 wherein the motor includes an alternating-current motor.

5. The belt sander of claim 1 comprising a gear train coupling the motor to the first roller, the gear train including a cross-axis gearing configured to translate a rotation of a motor shaft of the motor into a rotation of a drive pulley shaft that is perpendicular to the motor shaft and parallel to an axis of the first roller.

6. The belt sander of claim 1 comprising a platen disposed between the first roller and the second roller and between the sanding surface and the motor.

7. The belt sander of claim 6 wherein a center of gravity of the belt sander is substantially centered over the platen.

8. The belt sander of claim 6 wherein a length of the platen is less than approximately 150 mm.

9. The belt sander of claim 1 comprising an entry area for a power cord at a rear of the belt sander and contoured for gripping during operation of the belt sander.

10. The belt sander of claim 1 comprising a detachable auxiliary handle mounted at a front of the belt sander.

11. The belt sander of claim 1 wherein a length of the belt sander is less than approximately 350 mm.

12. The belt sander of claim 1 wherein a distance between a first axis of the first roller and a second axis of the second roller is less than approximately 250 mm.

13. The belt sander of claim 1 wherein a width of the handgrip is less than approximately 100 mm.

14. The belt sander of claim 1 wherein the motor is configured to provide at least 0.25 hp in driving the sanding belt.

15. The belt sander of claim 1 wherein the sanding belt is at least 300 mm in length, and the motor is configured to drive the sanding belt at a minimum of 600 sfpm.

16. The belt sander of claim 1 comprising a tracking mechanism for a belt sander, the tracking mechanism comprising: a sidewall of the belt sander; a yoke having a roller mount at a front end that is configured for mounting the front roller of the belt sander, the yoke being supported by the sidewall; a pivot pin mounted between the sidewall and the roller mount; and a tracking shaft extending through the sidewall and positioned to move against the yoke and pivot the yoke about the pivot pin.

17. The belt sander of claim 1 comprising a belt tracking mechanism for a belt sander, the belt tracking mechanism comprising: a frame supporting the second roller as an idle roller; said idle roller having an idle roller axle, said idle roller revolving about said idle roller axle; and a yoke supporting said idle roller axle, said yoke lying substantially orthogonal to said idle roller axis and allowing said idle roller and idle roller axis to freely translate along a longitudinal direction, while constraining said idle roller axis from movement along a vertical direction substantially orthogonal to said longitudinal direction.

18. The belt sander of claim 1 comprising a brush mounting system for a belt sander, the brush mounting system comprising: a concave brush card having a first brush box and a second brush box attached proximate a first end and a second end of the brush card; and at least one fastener attaching the brush card around a commutator of the motor of the belt sander with the first brush box and the second brush box positioned to provide contact to corresponding motor brushes and substantially opposing sides of the commutator.

19. A belt sander comprising: a sanding assembly including a rear roller and a front roller, the sanding assembly being configured to receive and rotate a sanding belt around the rear roller and the front roller during operation of the belt sander; a motor mounted over the sanding assembly and having a longitudinal rotational axis thereof being oriented in a direction substantially perpendicular to the rear roller and the front roller; and a handgrip at least partially encasing the motor and having a ton surface on an opposite side of the motor from the sanding assembly, the handgrip having opposed concave surfaces on two sides of the motor and extending at least partially between the sanding assembly and the top surface.

20. The belt sander of claim 19 wherein the handgrip substantially encases the motor above the sanding assembly.

21. The belt sander of claim 19 wherein a lower portion of the handgrip is at or below a bottom of the motor and between the sanding assembly and the motor.

22. The belt sander of claim 19 comprising a cross-axis gearing that is operably connected to the motor and that is operable to translate a motion of the motor into a rotation of the rear roller using a motor output shaft that is substantially perpendicular to the longitudinal rotational axis of the motor.

23. The belt sander of claim 19 wherein the motor includes an alternating current motor.

24. A method comprising: attaching a sanding assembly to a gear housing, the sanding assembly configured to receive a sanding belt and including a rear roller and a front roller; attaching a motor to the gear housing above the sanding assembly with a longitudinal rotational axis of the motor being oriented in a direction substantially perpendicular to the rear roller and the front roller; and attaching a handgrip at least partially encasing the motor, the handgrip including a convex surface extending in substantially a same direction as the longitudinal rotational axis of the motor, and further including opposed concave surfaces extending at least partially between the sanding assembly and the convex surface.

25. The method of claim 24 wherein attaching the handgrip comprises attaching the handgrip with a lower portion of the handgrip at or below a bottom of the motor.

26. The method of claim 24 wherein attaching the handgrip comprises attaching the handgrip substantially encasing the motor above the sanding assembly.

27. The method of claim 24 wherein attaching the sanding assembly comprises attaching a tracking box that includes a tracking mechanism configured to provide a tracking of the sanding belt on the sanding assembly.

28. A belt sander comprising: a sanding assembly having a first roller and a second roller, the sanding assembly being configured to receive a sanding belt around the first roller and the second roller to define a sanding surface therebetweeen; and a motor operationally coupled to the sanding assembly and positioned at least partially between the first roller and the second roller, the motor having a longitudinal rotational axis thereof being oriented in a direction substantially perpendicular to the first roller and the second roller; and a handgrip having a convex surface extending substantially in a same direction as the longitudinal rotational axis, and further having concave surfaces extending at least partially between the convex surface and the sanding assembly on opposed sides of the motor.

29. The belt sander of claim 28 wherein the handgrip is formed around at least a portion of the motor and substantially encasing the motor.

30. A belt sander comprising: a sanding assembly having a first roller and a second roller, the sanding assembly being configured to receive a sanding belt around the first roller and the second roller to define a sanding surface therebetweeen; a motor operationally coupled to the sanding assembly and positioned within a substantially cubic three-dimensional area defined by a perimeter of the sanding assembly, the motor having a longitudinal rotational axis thereof being oriented in a direction substantially perpendicular to the first roller and the second roller and a handgrip having a convex surface positioned on an opposite side of the motor from the sanding assembly and extending from the first roller to the second roller, the handgrip further having opposed concave surfaces extending at least partially between the opposite side of the motor and the sanding assembly.

31. The belt sander of claim 30 wherein the handgrip is formed around at least a portion of the motor and substantially encasing the motor.

Description:

TECHNICAL FIELD

This description relates to belt sanders.

BACKGROUND

Woodworkers often wish to smooth a surface of a workpiece prior to the completion of a woodworking project. For example, many workpieces require at least a minimal amount of sanding in order to remove any excess glue or rough edges, prior to completion of the project. Different types of sanders may be used for such sanding, e.g., to improve a surface quality and appearance of the workpiece. For example, such sanders may include a piece of sandpaper held in the woodworker's hand, or may include automated sanders, such as orbital sanders or quarter pad finishing sanders.

A belt sander is another example of a type of sander. Belt sanders generally include some mechanism for maintaining a sanding belt around two rollers. During operation, such belt sanders are designed to provide sufficient tension to the sanding belt to avoid skewing thereof, while avoiding excess tension that may lead to a breaking of the sanding belt.

SUMMARY

According to one general aspect, a belt sander includes a sanding assembly having a first roller and a second roller, the sanding assembly being configured to receive a sanding belt around the first roller and the second roller to define a sanding surface therebetweeen. The belt sander also includes a motor operationally coupled to the sanding assembly and opposite the sanding surface, the motor being configured to rotate at least the first roller and thereby rotate the sanding belt around the first roller and the second roller, and a handgrip formed around at least a portion of the motor and substantially encasing the motor.

Implementations may include one or more of the following features. For example, the motor may be oriented in-line with a longitudinal axis along the belt sander and intersecting the first roller and the second roller. A center of gravity of the belt sander may be substantially centered over the sanding assembly. The motor may be included within a three-dimensional area defined by a perimeter of the sanding assembly and extending in a direction of the motor. The motor may include an alternating-current motor.

A gear train coupling the motor to the first roller may be included, the gear train including a cross-axis gearing configured to translate a rotation of a motor shaft of the motor into a rotation of a drive pulley shaft that is perpendicular to the motor shaft and parallel to an axis of the first roller. A platen may be disposed between the first roller and the second roller and between the sanding surface and the motor, and a center of gravity of the belt sander may be substantially centered over the platen. The platen may have a length that is approximately less than 150 mm.

An entry area for a power cord may be included at a rear of the belt sander and contoured for gripping during operation of the belt sander. A detachable auxiliary handle mounted at a front of the belt sander also may be included.

A length of the belt sander may be less than approximately 350 mm. A distance between a first axis of the first roller and a second axis of the second roller may be less than approximately 250 mm. A width of the handgrip may be less than approximately 100 mm. The motor may be configured to provide at least 0.25 hp in driving the sanding belt. The sanding belt may be at least 300 mm in length, and the motor may be configured to drive the sanding belt at a minimum of 600 sfpm.

A tracking mechanism may be included, and the tracking mechanism may include a sidewall of the belt sander, a yoke having a roller mount at a front end that is configured for mounting the front roller of the belt sander, the yoke being supported by the sidewall, a pivot pin mounted between the sidewall and the roller mount, and a tracking shaft extending through the sidewall and positioned to move against the yoke and pivot the yoke about the pivot pin. Additionally, or alternatively, a belt tracking mechanism may be included, the belt tracking mechanism including a frame supporting the second roller as an idle roller, said idle roller having an idle roller axle, said idle roller revolving about said idle roller axle, and a yoke supporting said idle roller axle, said yoke lying substantially orthogonal to said idle roller axis and allowing said idle roller and idle roller axis to freely translate along a longitudinal direction, while constraining said idle roller axis from movement along a vertical direction substantially orthogonal to said longitudinal direction.

A brush mounting system may be included that includes a concave brush card having a first brush box and a second brush box attached proximate a first end and a second end of the brush card, and at least one fastener attaching the brush card around a commutator of the motor of the belt sander with the first brush box and the second brush box positioned to provide contact to corresponding motor brushes and substantially opposing sides of the commutator.

According to another general aspect, a belt sander includes a sanding assembly including a rear roller, a front roller, the sanding assembly being configured to receive and rotate a sanding belt around the rear roller and the front roller during operation of the belt sander. The belt sander includes a motor mounted over the sanding assembly and balanced with respect to the sanding assembly in a direction substantially parallel to an axis of the rear roller, and a handgrip at least partially encasing the motor.

Implementations may include one or more of the following features. For example, the handgrip may substantially encase the motor above the sanding assembly. A lower portion of the handgrip may be at or below a bottom of the motor. A cross-axis gearing may be included that is operably connected to the motor and that may be operable to translate a motion of the motor into a rotation of the rear roller. The motor may include an alternating current motor.

According to another general aspect, a sanding assembly is attached to a gear housing, the sanding assembly being configured to receive a sanding belt and including a rear roller and a front roller. A motor is attached to the gear housing above the sanding assembly, the motor being mounted in-line with an axis that intersects the rear roller and the front roller. A handgrip is attached at least partially encasing the motor.

Implementations may include one or more of the following features. For example, in attaching the handgrip, the handgrip may be attached with a lower portion of the handgrip at or below a bottom of the motor, and/or the handgrip may be attached substantially encasing the motor above the sanding assembly. In attaching the sanding assembly, a tracking box may be attached that may include a tracking mechanism configured to provide a tracking of the sanding belt on the sanding assembly.

According to another general aspect, a belt sander includes a sanding assembly having a first roller and a second roller, the sanding assembly being configured to receive a sanding belt around the first roller and the second roller to define a sanding surface therebetweeen, a motor operationally coupled to the sanding assembly and opposite the sanding surface, the motor being configured to provide at least 0.25 hp to rotate at least the first roller and thereby rotate the sanding belt around the first roller and the second roller, and a handgrip having a width of less than approximately 100 mm.

Implementations may include one or more of the following features. For example, the handgrip may be formed around at least a portion of the motor and substantially encasing the motor.

According to another general aspect, a belt sander includes a sanding assembly having a first roller and a second roller, the sanding assembly being configured to receive a sanding belt around the first roller and the second roller to define a sanding surface therebetweeen, and a motor operationally coupled to the sanding assembly and opposite the sanding surface, the motor being configured to provide at least 0.25 hp to rotate at least the first roller and thereby rotate the sanding belt around the first roller and the second roller, wherein the belt sander has a length of less than approximately 350 mm.

Implementations may include one or more of the following features. For example, the handgrip may be formed around at least a portion of the motor and substantially encasing the motor.

According to another general aspect, a tracking mechanism for a belt sander includes a sidewall of the belt sander, and a yoke having a roller mount at a front end that is configured for mounting a front roller of the belt sander, the yoke being supported by the sidewall. A pivot pin is mounted between the sidewall and the roller mount, and a tracking shaft extends through the sidewall and is positioned to move against the yoke and pivot the yoke about the pivot pin.

Implementations may include one or more of the following features. For example, a side-loaded spring may be loaded against the yoke on a side of the belt sander opposite to the sidewall, the pivot pin, and the tracking shaft. The tracking shaft may be movable against the yoke in response to a user rotation of a tracking knob attached thereto and exterior to the belt sander. Movement of the tracking shaft against the yoke may alter an angle of a front roller of the belt sander relative to a rear roller of the belt sander.

The sidewall may include a groove in which the pivot pin is mounted. The pivot pin may be fixed to the sidewall and slidable against the roller mount to allow longitudinal movement of the yoke relative to the sidewall. The pivot pin may be fixed to the roller mount and slidable against a groove of the sidewall to allow longitudinal movement of the yoke relative to the sidewall. A distance from the tracking shaft to the pivot pin may be within a range of 70-100 mm, e.g., may be within a range of 84-92 mm. A distance from the tracking shaft to the pivot pin may be maximized relative to one or more of a length of the belt sander, a length of the sanding belt, a distance between a front axis of the front roller and a rear axis of a rear roller of the belt sander, and/or a length of a platen disposed in contact with the sanding belt during operation of the belt sander.

A tracking box may be mounted on the sidewall that contains slots in which the yoke is mounted. A degree of movement of the tracking shaft may be selectable to provide a desired tracking of a sanding belt on the front roller and a rear roller of the belt sander.

According to another general aspect, a tracking mechanism for a belt sander includes a roller mount configured to hold a front roller of the belt sander, a pivot pin in contact with the roller mount and a sidewall of the belt sander, and a tracking shaft extending through the sidewall and movable against a yoke attached to the roller mount, for rotation of the roller mount about the pivot pin.

Implementations may include one or more of the following features. For example, A spring may be included on an opposite side of the yoke from the pivot pin and tracking shaft and may load the yoke against the pivot pin and tracking shaft. The yoke may be mounted within slots of a tracking box that is mounted on the sidewall. Rotation of the roller mount about the pivot pin may adjust a degree of parallelism between the front roller and a rear roller of the belt sander. The tracking shaft may extend through the sidewall between a rear roller of the belt sander and the front roller, and the tracking shaft may be located toward the rear roller.

According to another general aspect, a tracking mechanism of a belt sander is constructed. A sidewall of the belt sander is formed, the sidewall including a bore and a groove. A tracking shaft is inserted through the bore, a pivot pin is positioned in the groove, and a roller mount configured to hold the front roller is mounted against the pivot pin. A yoke attached to the roller mount is positioned against the tracking shaft, and the yoke and the roller mount are loaded against the tracking shaft and pivot pin, respectively.

Implementations may include one or more of the following features. For example, in loading the yoke and the roller mount a spring may be positioned against the yoke on a side of the belt sander opposite the sidewall. A tracking knob may be mounted on an end of the tracking shaft exterior to the belt sander, wherein rotation of the tracking knob may be translated into motion of the tracking shaft against the yoke and corresponding rotation of the roller mount about the pivot pin.

According to another general aspect, a belt tension control mechanism for a belt sander includes a yoke having a roller mount configured to support a front roller, the yoke having a surface extending away from the roller mount and being movable with respect to a rear roller, a flange attached to the surface and at an angle with the surface, a cam shaft having grooves formed therein and extending through the frame, the cam shaft having a cam extending therefrom in a vicinity of the flange, a knob having mated grooves formed therein and configured to allow sliding of the knob onto the cam shaft, and a belt tension knob that is exterior to a frame of the belt sander and configured for rotation thereof to provide contact between the cam and the flange and resulting motion of the yoke and the roller mount in a direction toward the rear roller.

Implementations may include one or more of the following features. For example, the motion of the roller mount toward the rear roller may be sufficient to permit installation of a sanding belt around the rear roller and the front roller for operation of the belt sander therewith. A spring loading the yoke and roller mount in a direction away from the rear roller also may be included.

According to another general aspect, a tracking box for a belt sander includes a frame attached to a sidewall of the belt sander between a front roller and a rear roller of the belt sander, the frame having a front portion and a bottom portion, and having at least one groove along a length of the front portion. A platen is included having a top surface, and having a flange formed above the top surface at one end thereof and inserted into the groove to maintain the top surface of the platen relative to the bottom portion of the frame.

Implementations may include one or more of the following features. For example, an adhesive pressure-sensitive surface may be attached to the platen and positioned between the top surface of the platen and the bottom portion of the frame. A tracking box cover may be attached to the frame and may maintain the platen in position with respect to the frame.

The frame may include a secondary groove on a back portion of the frame, the platen may include a secondary flange formed above the top surface of the platen at a second end thereof, and the secondary flange may be inserted into the secondary groove.

The groove and the flange may be substantially triangular in shape. The platen may extend beyond the frame in a direction toward the rear roller. Slots may be formed in the frame that are substantially parallel to an axis of the rear roller, and a yoke may be positioned within the slots, the yoke being attached to a roller mount configured to receive the front roller.

According to another general aspect, a frame is formed having a groove along a first surface thereof. The frame is mounted in front of a rear roller axle of a belt sander, a platen having a flange above a top surface thereof is formed, and the platen is joined to the frame by inserting the flange into the groove to thereby match the top surface of the flange to a bottom surface of the frame.

Implementations may include one or more of the following features. For example, in forming the frame, the frame may be extruded with the groove formed therein. In forming the platen, metal may be stamped into a desired shape of the platen, and/or the flange may be formed in a substantially concave shape.

According to another general aspect, a belt sander includes a first roller, a second roller, a motor operationally coupled to the first roller to cause rotation thereof, a groove formed in the first roller, and a band within the groove, the band being in contact with a sanding belt of the belt sander during operation thereof and configured to impart motion of the first roller to the sanding belt for rotation of the sanding belt around the first roller and the second roller.

Implementations may include one or more of the following features. For example, the groove may be formed substantially centered around a middle of the first roller. The band may include an elastimer and/or rubber material. The rear roller may include a crowning at a center portion thereof.

According to another general aspect, a rear roller of a belt sander is formed. A groove is formed in the rear roller, and a drive band is attached within the groove.

Implementations may include one or more of the following features. For example, in forming the rear roller the rear roller may be formed using Aluminum. In forming the groove, the groove may be formed substantially centered about a middle of the rear roller.

According to another general aspect, a drive mechanism for a belt sander includes a motor, a drive pulley operationally coupled to the motor and rotated by the motor, a driven pulley operationally coupled to a drive roller of the belt sander to rotate the drive roller, and a pre-tensioned drive belt around the drive pulley and the driven pulley to translate rotation of the drive pulley by the motor into rotation of the drive roller, the pre-tensioned drive belt having sufficient pre-tensioning to allow slippage of the pre-tensioned drive belt in response to a selected torque value of the motor.

Implementations may include one or more of the following features. For example, the selected torque value may be outside of a torque range of the motor. An amount of the slippage provided by the pre-tensioned drive belt may be determined to provide time for stoppage of the belt sander in response to a jamming of the belt sander. The selected torque value may be determined based on a torque value that is potentially damaging to the motor and/or associated gears. The selected torque value may be determined based on one or more of: a length of the pre-tensioned drive belt, a diameter of the drive pulley and/or the driven pulley, and/or a center distance between the drive pulley and the driven pulley.

According to another general aspect, a belt sander protection mechanism includes a housing having a sidewall and a topwall joined to the sidewall, the topwall having a slot formed therein that is proximate to a surface of the sidewall, a wear plate having a first end positioned within the slot and maintained against the sidewall, and a tracking box fastened to the housing and trapping a second end of the wear plate between the tracking box and the surface of the sidewall.

Implementations may include one or more of the following features. For example, the wear plate may extend from the sidewall and may contact a sanding belt of the belt sander when the sanding belt skews in a direction of the sidewall. The topwall may be substantially perpendicular to the sidewall. A secondary slot formed in the topwall adjacent to the sidewall may be included, and a secondary wear plate may be maintained against the sidewall by the secondary slot and by the tracking box.

The wear plate may include a ceramic material. The wear plate may be substantially rectangular in shape. Side-locating ribs may be formed in the sidewall and may restrict a motion of the wear plate in a direction parallel to the sidewall.

According to another general aspect, a gear box of a belt sander includes a seal assembly through which a shaft is inserted, the shaft being attached to a gear portion, wherein the seal assembly and gear portion are slip-fit into a bore of the gear box with the gear portion being interior to the seal assembly within the gear box, and a bearing through which the shaft is inserted, the bearing being slip-fit into the bore and exterior to the seal assembly.

Implementations may include one or more of the following features. For example, the gear portion may be positioned relative to the seal assembly to contact the seal assembly and thereby remove the seal assembly from the bore in response to a retraction of the shaft from the gear box.

The seal assembly may include a seal holder having a bore formed therein and containing a lip seal. The gear portion may be positioned relative to the seal assembly to contact the seal holder and thereby remove the seal assembly from the bore in response to a retraction of the shaft from the gear box, substantially without damaging the lip seal. A smallest diameter on a flange of the gear portion may be larger than a diameter of the lip seal. The seal assembly may include a seal holder having a groove formed around an outer perimeter thereof, and the groove may contain an O-ring or a rubber gasket.

The gear portion may include a gear and the shaft may include a jackshaft of a drive pulley that is configured to rotate a drive belt of the belt sander. The gear portion may include a pinion and the shaft may include a motor shaft. The shaft may include a drive pulley shaft and a motor shaft that may be positioned substantially perpendicularly to one another within the gear box.

According to another general aspect, a seal assembly is assembled, and a shaft is inserted through a bearing, the seal assembly, and a gear portion. The gear portion, seal assembly, and bearing are inserted into a bore of a gearbox of a belt sander.

Implementations may include one or more of the following features. For example, in assembling a seal assembly a lip seal may be positioned into a seal holder, and a ring may be placed within a groove formed around an outer perimeter of the seal holder. In inserting a shaft, a drive pulley shaft may be inserted through the bearing, the seal assembly, and the gear portion. In inserting a shaft, a motor shaft may be inserted through the bearing, the seal assembly, and the gear portion.

According to another general aspect, brush mounting system for a belt sander includes a concave brush card having a first brush box and a second brush box attached proximate a first end and a second end of the brush card, and at least one fastener attaching the brush card around a commutator of a motor of the belt sander with the first brush box and the second brush box positioned to provide contact to corresponding motor brushes and substantially opposing sides of the commutator.

Implementations may include one or more of the following features. For example, the brush card may be accessible by removal of a side portion of a handgrip of the belt sander. The brush card may include a first spring associated with the first brush box and loading associated brushes against the commutator to maintain electrical contact therebetween. The brush card may include a second spring associated with the second brush box and loading associated brushes against the commutator to maintain electrical contact therebetween. The first brush box may be mounted onto the brush card with mounting tabs. Electrical contacts may be associated with the first brush box and the second brush box and may be positioned to transmit electrical energy to the brushes when a power switch of the belt sander is turned on. The fastener may include a screw inserted through a substantially center portion of the brush card. The fastener may include at least one mounting tab at an end of the brush card that snaps into a mated opening proximate to the motor.

According to another general aspect, a dust collection system for a belt sander includes an opening formed in a rear of a casing of the belt sander, and a detachable vacuum attachment nozzle that is configured to snap into the opening using tabs at a first end thereof, and configured to receive a vacuum attachment at a second end thereof.

Implementations may include one or more of the following features. For example, the tabs may include detents, and the opening may include detent ribs against which the detents may be snapped into place by an insertion and rotation of the vacuum attachment nozzle.

According to another general aspect, a belt tracking mechanism for a belt sander includes a frame supporting an idle roller, said idle roller having an idle roller axle, said idle roller revolving about said idle roller axle, and a yoke supporting said idle roller axle, said yoke lying substantially orthogonal to said idle roller axis and allowing said idle roller and idle roller axis to freely translate along a longitudinal direction, while constraining said idle roller axis from movement along a vertical direction substantially orthogonal to said longitudinal direction.

Implementations may include one or more of the following features. For example, a side wall of said frame may contain a hollow groove, said yoke may have a protrusion received by said groove to allow said idle roller axis to freely translate along said longitudinal direction while constraining said idle roller axis from movement along a vertical direction substantially orthogonal to said longitudinal direction.

A longitudinally extending compression spring may be included to bias said idle roller along said longitudinal direction, said longitudinally extending compression spring parallel with said yoke. A laterally extending compression spring substantially perpendicular to said longitudinally extending compression spring may be included, said laterally extending compression spring may be connected to a post fixed to said side wall of said frame, and said laterally extending compression spring may be biasing said yoke towards said side wall.

A drive roller may be included having a drive roller axle and supported by said frame, said drive roller and said idle roller receiving a belt for said belt sander. A side wall of said frame may be included, said side wall longitudinally extending, and a mechanism for adjusting the angle formed between said longitudinally extending yoke which supports said idle roller axis, and said longitudinally extending side wall of said frame.

The mechanism for adjusting the angle may include a threaded post fixedly embedded in said side wall, said threaded post spacing the longitudinally extending yoke from said side wall, and said threaded post, in response to rotation of said threaded post within said side wall, extending a lateral distance between said yoke and said side wall, said lateral distance being substantially orthogonal to said longitudinal and vertical directions. Said threaded post may include a rotatable thumbscrew, and said yoke may contact said side wall at a protrusion contact point received by said side wall, and said post may extend along said lateral distance and may be located at a position longitudinal to said protrusion contact point.

According to another general aspect, a belt tracking mechanism includes a frame supporting an idle roller, revolving about an idle roller axis, a drive roller, revolving about a drive roller axis and a platen disposed between said idle and drive rollers. The belt tracking mechanism includes a longitudinally extending side wall of said frame, a longitudinally-extending yoke slideably supported by said side wall, said yoke supporting said idle roller, said idle roller axis substantially orthogonal to said yoke. Said yoke is freely translatable along said longitudinal direction while being substantially constrained from movement along a vertical direction orthogonal to said longitudinal direction.

Implementations may include one or more of the following features. For example, a mechanism for adjusting a degree of parallelism between said idle roller axis and said drive roller axis may be included, where said mechanism may be connected to said frame and configured to adjust a degree of angular separation between the side wall of said frame and said longitudinally extending yoke. Said degree of angular separation may be formed by said mechanism moving said yoke in a lateral direction relative to said side wall, said lateral direction substantially orthogonal to said longitudinal and vertical directions.

Said mechanism for adjusting the degree of parallelism between said idle roller axis and said drive roller axis may include a threaded thumbscrew extending along said lateral direction, with a fork slideably supporting said yoke and attached to said thumbscrew. Said yoke may contact said side wall at a protrusion contact point received by said side wall, and said threaded thumbscrew may be located at position longitudinal to said protrusion contact point. Said side wall of said frame may contain a hollow groove, and said yoke may have a protrusion received by said groove to allow said idle roller axis to freely translate along a longitudinal direction while constraining said idle roller axis from movement along a vertical direction substantially orthogonal to said longitudinal direction.

A longitudinally extending compression spring biasing said idle roller along said longitudinal direction may be included. A laterally extending compression spring substantially perpendicular to said longitudinally extending compression spring may be included, and said laterally extending compression spring may be connected to a post connected to said side wall of said frame, said laterally extending compression spring biasing said yoke towards said side wall.

The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are perspective topside views of an example belt sander.

FIGS. 2A and 2B are perspective topside cut-away views of the belt sander of FIGS. 1A and 1B.

FIG. 3 is a top cut-away view of the belt sander of FIGS. 1A and 1B.

FIGS. 4A and 4B illustrate examples of a structure and operation of an example implementation of a belt tension adjustment mechanism of FIG. 3.

FIGS. 5A-5D illustrate example tracking box designs and implementations for use with the belt sander of FIGS. 1A and 1B.

FIGS. 6A and 6B illustrate a drive mechanism for the belt sander 100 of FIGS. 1A and 1B.

FIG. 7 illustrates an example implementation of the belt sander of FIGS. 1A and 1B that includes a pre-tensioned drive belt.

FIGS. 8A-8C illustrate an example implementation of the belt sander of FIGS. 1A and 1B using fitted wear plates.

FIGS. 9A-9D illustrate sealing techniques associated with a gear train of the belt sander 100 of FIGS. 1A and 1B.

FIGS. 10A-10C illustrate a motor brush system for use in the belt sander of FIGS. 1A and 1B.

FIGS. 11A-11C illustrate examples of vacuum sub-assemblies for use with the belt sander of FIGS. 1A and 1B.

FIG. 12 is a perspective view of an example alternative implementation of the belt sander 100 of FIGS. 1A and 1B.

FIG. 13 is a flowchart illustrating methods of manufacturing associated with the construction and/or assembly of the belt sander of FIGS. 1A and 1B.

FIG. 14 is a flowchart illustrating alternative implementations of the flowchart of FIG. 13.

FIG. 15 is a flowchart illustrating alternative implementations of the flowchart of FIG. 13.

FIG. 16 is a flowchart illustrating alternative implementations of the flowchart of FIG. 13.

FIG. 17 is a flowchart illustrating alternative implementations of the flowchart of FIG. 13.

FIG. 18 is an isometric illustration of an alternative example implementation of a belt sander.

FIG. 19 is an alternate side view of the belt sander shown in FIG. 18.

FIG. 20 is a partial side view of the belt sander shown in FIG. 18, wherein a sanding assembly including a drive belt pulley and a pitch belt is illustrated.

FIG. 21 is an isometric view of the belt sander shown in FIG. 18, wherein the motor housing is removed revealing a gearing system, including a gear housing, for transmitting torque to the drive belt pulley.

FIG. 22 is a cross-sectional view of the belt sander shown in FIG. 18, wherein a sanding assembly including a sanding belt wrapped around a front roller and a rear roller is illustrated.

FIG. 23 is an isometric view of the belt sander shown in FIG. 18, wherein the placement of a user's hand is illustrated.

FIG. 24 is a perspective topside view of an additional or alternative belt tracking mechanism for a belt sander.

FIG. 25 is a perspective top and front side view of the belt tracking mechanism of FIG. 24.

FIG. 26 is a cross sectional view of the belt tracking mechanism along a lateral section line of FIG. 25.

FIG. 27 is a backside view of the belt tracking mechanism of FIG. 24.

FIG. 28 is a top view of the belt tracking mechanism of FIG. 24.

FIG. 29 is a front side view of the belt tracking mechanism of FIG. 24.

FIG. 30 is a schematic of a longitudinal cross section of the belt tracking mechanism of FIG. 24, showing a parallelism alignment adjustment mechanism of the belt sander of FIG. 24.

DETAILED DESCRIPTION

FIG. 1A is perspective topside view of an example belt sander 100 . The belt sander 100 provides a small, lightweight belt sander that provides sufficient power to perform sanding jobs previously associated with larger, heavier belt sanders. The belt sander 100 may thus be used, for example, by cabinet, trim, or stair installers, or in other applications in which sanding is required to be performed in a fast and thorough manner. For example, in extensive or time-consuming sanding projects, the belt sander 100 may reduce a fatigue of a user, due to the lightweight and maneuverable nature of the belt sander 100 . Further, the belt sander 100 provides for sanding in small or relatively inaccessible locations, and, in some implementations, allows for a flexible, multi-positional, one-handed grip. Other features and advantages are described in more detail, below.

In the example of FIG. 1A, the belt sander 100 includes a rear roller 102 and a front roller 104 . A continuous sanding belt (not shown in FIG. 1A) may be provided between the rear roller 102 and the front roller 104 . In example implementations, rotation of the rear roller 102 (i.e., use of the rear roller 102 as a drive roller) may cause rotation of the sanding belt around the rear roller 102 and the front roller 104 . Then, application of the rotating sanding belt to an underlying surface (also not shown in FIG. 1A) may provide fast, thorough smoothing of the surface. In some example implementations, the sanding belt may include a 2.5″×14″ sanding belt, although other size sanding belts also may be used.

During rotation, the sanding belt may be pressured against the surface being sanded by a force applied by the user of the belt sander 100 , and by a platen 106 disposed between the rear roller 102 and the front roller 104 . That is, during rotation, at least a part of the sanding belt is continuously disposed between the platen 106 and the surface being sanded. In some implementations, the platen 106 may be formed from stamped metal, such as, for example, Aluminum or stainless steel.

The platen 106 may be attached to a tracking box 108 . As described in more detail below, the tracking box 108 may include one or more tracking mechanisms for ensuring that the sanding belt is maintained between the rear roller 102 and the front roller 104 with proper tension and in a proper position. For example, in a case where the user notices that the sanding belt skews to a particular side during operation of the belt sander 100 , such tracking mechanisms may allow the user to adjust a position of the front roller 104 relative to the rear roller 102 , in order to counter such skewing.

The tracking box 108 includes, or is associated with, a tracking box cover 110 . The tracking box cover 110 may be removable, for access to, and/or repair of, the tracking mechanism(s) or other internal components of the tracking box 108 .

Thus, some or all of the components 102 - 110 , and associated components, may be considered to form a sanding assembly 112 for performing the various sanding operations referenced herein, or other sanding operations. As described in more detail below, the sanding assembly 112 may be operated by, and in conjunction with, a motor that is partially or wholly contained within a handgrip 114 . The handgrip 114 may thus be grasped during operation of the belt sander 100 by the user, using a single hand if desired/preferred, for use and control of the belt sander 100 .

In the implementation of FIG. 1A, the handgrip 114 includes a right clamshell 114 a and a left clamshell 114 b (where left/right are defined as shown, and as viewed from a rear of the belt sander 100 ). Accordingly, the right clamshell 114 a and the left clamshell 114 b may be formed, installed, and/or removed independently of one another, so as to provide easy, convenient, and flexible access to an interior of the belt sander 100 (i.e., to an interior of the handgrip 114 ).

In some implementations, the handgrip 114 may be formed of contoured, overmolded plastic, and/or using glass-filled nylon. Accordingly, the handgrip 114 provides a convenient, reliable, and comfortable gripping surface for the user during operation of the belt sander 100 .

Further in FIG. 1A, an on/off switch 116 is provided at a front of the belt sander 100 , as shown. Accordingly, the user may quickly and easily access and operate the on/off switch 116 during operation of the belt sander 100 . Such accessibility may be important, for example, when the user wishes to stop an operation of the belt sander 100 on short notice. Of course, other switches may be used in conjunction with the on/off switch 116 , including, for example, a switch or dial that allows a user-selectable speed of the belt sander 100 .

Further in FIG. 11A, a ventilation grill 118 allows for ventilation and cooling of the belt sander 100 (e.g., of an encased motor within the handgrip 114 ) during operation of the belt sander 100 . Meanwhile, a cord 120 provides power to the belt sander 100 from an electrical outlet. Of course, in other implementations, additional or alternate power sources may be used, including, for example, batteries located within a battery compartment (not shown) associated with the belt sander 100 .

A casing 122 is illustrated that may be formed of, for example, cast Aluminum. In some implementations, the casing 122 may be formed integrally with the handgrip 114 a / 114 b.

FIG. 1B is a topside perspective view of the belt sander 100 from the opposite side of that shown in FIG. 1A. That is, FIG. 1B illustrates a view of the belt sander 100 from a left side, with respect to the orientation referenced above. Accordingly, the left clamshell 114 b is in substantially full view in the view of FIG. 1B, as shown.

In FIG. 1B, a tracking knob 124 is illustrated. As described in more detail below, e.g., with reference to FIG. 3, the tracking knob 124 may be used to operate the tracking mechanism(s) contained within the tracking box 108 , so as to maintain a proper position and tension of the sanding belt of the belt sander 100 .

A belt tension knob 126 may be used to load or unload the sanding belt. For example, as described in more detail below with respect to FIGS. 4A and 4B, the belt tension knob 126 may be rotated upwards to release a tension on the sanding belt (e.g., by moving the front roller 104 in a direction toward the rear roller 102 ), and may be rotated downward (e.g., into the position shown in FIG. 1B) to increase the tension on the sanding belt 100 for operation thereof.

Also in FIG. 1B, a drive belt cover 128 is illustrated. The drive belt cover 128 is a cover for a drive belt, not shown in FIG. 1B, that is used to translate motion from gears associated with, and rotated by, a motor within the handgrip 114 to the rear roller 102 . In this way, the rear roller 102 is used as a drive roller for the belt sander 100 , so that the rear roller 102 causes rotation of the sanding paper around the rear roller 102 , the platen 106 , and the front roller 104 . In such implementations, the front roller 104 may be an idle roller that allows rotation of the sanding paper without requiring any source of rotational power other than the driven rotation of the rear roller 102 (along with force applied by the user).

FIG. 2A is a topside perspective cut-away view of the belt sander 100 . In FIG. 2A, the belt sander 100 is viewed from the right side, and the right clamshell 114 a is removed.

Thus, in FIG. 2A, a motor 202 is illustrated as an example of the motor included within (i.e., partially and/or substantially encased by) the handgrip 114 and powering the rear roller 102 , as described above with respect to FIGS. 1A and 1B. That is, for example, the handgrip 114 may generally surround any portion of the motor 202 that is not otherwise attached to the sanding assembly 112 or other portion of the belt sander 100 , and/or may include at least a lower portion that is positioned at or below a bottom of the motor 202 .

In the example of FIG. 2A, the motor 202 may include an alternating current (AC) motor that is oriented in-line with a direction of travel of the belt sander 100 , such as, for example, a 59 mm AC motor. That is, in the example of FIG. 2A, the motor 202 is aligned along a longitudinal axis 204 intersecting the rear roller 102 and the front roller 104 , as shown.

Thus, both the sanding assembly 112 and the motor 202 may be substantially centered with respect to one another along the longitudinal axis 204 , so that the handgrip 114 also may be centered along the longitudinal axis 204 . As a result, for example, a weight of the motor 202 may be evenly-distributed from left to right, and may be substantially centered over the sanding assembly 112 . Put another way, a center of gravity of the motor 202 may be located substantially over a center of the sanding assembly 112 . Accordingly, the belt sander 100 may be very well-balanced during operation, even when the belt sander 100 is operated upside-down, or sideways (e.g., along a vertical surface).

Further, the motor 202 may be contained, or substantially contained, within an area defined by the sanding assembly 112 , and/or within an area defined by the platen 106 . That is, for example, the sanding assembly 112 may define a two-dimensional area extending from one side of the rear roller 102 to the other (i.e., perpendicularly to the axis 204 along an axis of the rear roller 102 ), and extending from a back edge of the rear roller 102 to a front edge of the front roller 104 . In the example of FIG. 2A, then, extension of this two dimensional area defined by a perimeter of the sanding assembly 112 in a perpendicular direction toward the motor 202 may be understood to contain the motor 202 within a resulting three-dimensional space. Again, such placement of the motor 202 may result in a compact, well-balanced, yet powerful belt sanding device.

Finally in FIG. 2A, a gearbox 206 is illustrated that includes a gear train (not shown in FIG. 2A, and examples of which are provided in more detail below, e.g., with respect to FIGS. 9A-9D). Generally, though, the gearbox 206 may include a worm gear or cross-axis helical gear, so that (as described below with respect to FIG. 2B) rotation of the in-line motor 202 may be translated into rotation of the rear roller 102 . In this way, corresponding rotation of the sanding belt may be obtained in conjunction with the in-line motor design referenced herein and illustrated in corresponding figures.

FIG. 2B is another topside perspective cut-away view of the belt sander 100 . In FIG. 2B, the belt sander 100 is viewed from the left side, and both the right clamshell 114 a and the left clamshell 114 b are removed.

In FIG. 2B, a drive belt 208 is illustrated (which should be understood from FIG. 1B to be contained within the drive belt cover 128 ) as being connected both to a drive pulley 210 and to a driven pulley 212 (i.e., a member that is rotatably connected to an axle of the rear roller 102 , so that rotation of the driven pulley 212 causes rotation of the rear roller 102 ). As is thus apparent from FIGS. 2A and 2B, rotation of the motor 202 is translated through the gearbox 206 to rotation of the drive pulley 210 , which causes the drive belt 208 to rotate and thus causes the rotation of the driven pulley 212 . Rotation of the driven pulley 212 leads to rotation of the rear roller 102 itself, thus resulting in rotation of the sanding belt around the sanding assembly 102 .

Finally in FIG. 2B, a gear housing 214 refers to a metal portion of the belt sander 100 that is joined with, associated with, and/or integral to, the gearbox 206 , and that provides a frame for mounting various elements of the belt sander 100 . For example, as described in more detail herein, the gear housing 214 may be joined to, and/or support, the tracking box 108 , the rear roller 102 , the tracking knob 124 , the belt tension knob 126 , as well as the motor 202 and the gearbox 206 themselves.

In the examples of FIGS. 1A-2B, and in following examples, the belt sander 100 may be implemented with a variety of size and power characteristics. For example, a width of the handgrip 114 may be less than approximately 100 mm, while an overall front-to-back length of the belt sander 100 may be less than approximately 300 mm. In another example, a length of the platen 106 (e.g., a length of a flat portion of the platen 106 above the sanding belt) may be less than approximately 100 mm. A distance between an axis of the front roller 104 and the rear roller 102 may be, in some example implementations, less than approximately 200 mm. As another example, a length of the sanding belt may be at least 300 mm (e.g., 355.6 mm for a 2.5×14 inch sanding belt). In determining or describing the above distances, or other distances, it should be understood that the distances may be measured with respect to functional aspects needed or used in an operation of the belt sander; so that, for example, inclusion of an auxiliary handle (or any other extension) may or may not be considered in determining the above characteristics, as would be appropriate.

The motor 202 may be configured to provide a t least 0.25 hp, and, for example, may be configured to drive a 2.5×14 in sanding belt at a minimum of 600 sfpm (surface feet per minute), e.g., at 800 sfpm. Of course, all such characteristics, e.g., length, width, or power, are merely intended as examples, and many other values and quantities also may be used, and, moreover, various ratios or relationships between these characteristics, or other characteristics, also may be used.

FIG. 3 is a top cut-away view of the belt sander 100 of FIGS. 1A and 1B. That is, FIG. 3 illustrates (portions of) the sanding assembly 112 from above, without showing the handgrip 114 , the motor 202 , the gearbox 206 , or other intervening components, and without necessarily showing all components of the sanding assembly 112 (e.g., the tracking box 108 may not be illustrated in its entirety).

In FIG. 3, the tracking box 108 is illustrated as containing a tracking mechanism that includes a yoke 302 . The yoke 302 may comprise, for example, stamped metal, such as Aluminum or stainless steel. As shown, the yoke 302 provides a roller mount 303 for the front roller 104 , which allows the front roller 104 to rotate freely. As described and illustrated in more detail below with respect to FIGS. 5A-5C, the yoke 302 may be mounted in slots of the tracking box 108 , the slots being parallel to the axes of the rear roller 102 and the front roller 104 , so that the yoke 302 and the roller mount 303 may generally be movable in directions both parallel and perpendicular to the axes of the rear roller 102 and the front roller 104 .

Such movement of the yoke 302 may be constrained, by a front load spring 304 and a side load spring 306 . That is, the front load spring 304 may be loaded against a portion of the tracking box 108 (the portion not shown in FIG. 3), so as to constrain a motion of the yoke 302 (and thereby of the front roller 104 ) in a direction toward the rear roller 102 . Meanwhile, the side load spring 306 may be used to restrict a motion of the yoke 302 (and the roller mount 303 and the front roller 104 ) away from the gear housing 114 , parallel to an axis of the rear roller 102 . A plastic slider 308 is used to maintain contact between the side load spring 306 and the yoke 302 .

The front load spring 304 loads the yoke 302 against a cam shaft 310 associated with the belt tension knob 126 , which thus restricts motion of the yoke 302 (and the front roller 104 ) in a direction away from the rear roller 102 . More specifically, a flange 312 (which may be formed using a hardened stamping to prevent wear) of the yoke 302 is maintained in pressure against the cam shaft 310 . In this way, as referenced above and described/illustrated in more detail below with respect to FIGS. 4A and 4B, rotation of the belt tension knob 126 may cause rotation of a cam 314 at the end of the cam shaft 310 , thereby causing the cam 314 to exert pressure against the flange 312 .

Consequently, the flange 312 is pushed toward the rear roller 102 , causing a motion of the yoke 302 (and the front roller 104 ) in the same direction (thereby temporarily further loading the front load spring 304 ). In this way, since the front roller 104 and the rear roller 102 move closer to one another, a belt tension on the sanding belt is reduced, so that the sanding belt may be removed and/or installed or re-installed. Conversely, motion of the belt tension knob 126 in the opposite direction after removal and subsequent (re-)installation of the sanding belt re-establishes tension of the sanding belt, for subsequent operation of the belt sander 100 .

Further in FIG. 3, a pin 316 is illustrated that defines a pivot point for the tracking mechanism of the belt sander 100 . That is, for example, as may be appreciated from FIG. 3 and from the above description, rotation of the tracking knob 124 in a first direction may cause tracking shaft 318 of the tracking knob 124 to move toward (a rear of) the yoke 302 , while rotation of the tracking knob 124 in a second, opposite direction causes the tracking shaft 318 to move away from (a rear of) the yoke 302 .

In FIG. 3, the pin 316 is located in a divot or groove 320 , and may be fixed in position, therein, while being slidably engaged with the yoke 302 . In other implementations, however, the pin 316 may be fixed to the yoke 302 , and may slide within the groove 320 and/or along the gear housing 214 . Other implementation details may be included that are not necessarily illustrated in FIG. 3. For example, an additional (compression) spring may be associated with the tracking knob 124 and/or the tracking shaft 318 , so as to maintain pressure on the tracking knob 124 and prevent undesired motion thereof.

As a result of the structure of FIG. 3, or similar structures, the yoke 302 may pivot about the pivot point established by the pin 316 . That is, a degree of parallelism between the rear roller 102 and the front roller 104 may be adjusted. Accordingly, a tracking mechanism is provided by which a tendency of the sanding belt to skew inappropriately (e.g., to veer to one side or the other on the rollers 102 , 104 ) may be reduced, and an appropriate tension and/or position of the sanding belt may be maintained. In this way, for example, undesired exposure of the rear roller 102 , the front roller 104 , or the platen 106 may be reduced or eliminated during operation of the belt sander 100 , and a lifetime and reliability of the belt sander 100 may be improved. Moreover, the examples of the described tracking mechanism allow for rotation of the front roller 104 about the pivot pin 316 , while permitting little or no side-to-side motion (i.e. in a direction parallel to an axis of the rear roller 102 ) of the roller mount.

In some example implementations, a tracking distance from the tracking shaft 318 to the pivot point 316 may be maximized relative to and/or as a function of, other parameters of the belt sander 100 . For example, the tracking distance may be maximized with respect to one or more of a length of the belt sander, a length of the sanding belt, a distance between a front axis of the front roller and a rear axis of a rear roller of the belt sander, and/or a length of a platen disposed in contact with the sanding belt during operation of the belt sander. In some implementations, the tracking distance from the tracking shaft 318 to the pivot point 316 may be within a range of 70-100 mm, e.g., may be within a range of 84-92 mm, such as, for example, 88 mm. To give specific but non-limiting examples of resulting ratio(s) of the tracking distance to other parameters of the belt sander 100 , an example of a first ratio of the tracking distance to the overall tool length may be at least 0.2 (e.g., a ratio of 0.352 when the respective measurements are 88 mm to 250 mm). An example of a second ratio of the tracking distance to the sanding belt length may be at least 0.14 (e.g., a ratio of 0.247 when the respective measurements are 88 mm to 355.6 mm). An example of a third ratio of the tracking distance to the distance between axes of the rear roller 102 and the front roller 104 may be at least 0.45 (e.g., a ratio of 0.657 when the respective measurements are 88 mm to 134 mm). An example of a fourth ratio of the tracking distance to the platen length may be at least 1.3 (e.g., a ratio of 1.426 when the respective measurements are 88 mm to 61.7 mm).

FIGS. 4A and 4B illustrate examples of a structure and operation of an example implementation of the belt tension adjustment mechanism of FIG. 3, i.e., of the belt tension knob 126 , the cam shaft 310 , the cam 314 , and the flange 312 (of the yoke 302 ). FIG. 4A provides a perspective side view in which the cam 314 is illustrated in a forward position, which would correspond to a full tension on the sanding belt and a ready condition for operation of the belt sander 100 .

As should be understood from the above description, however, appropriate rotation of the belt tension knob 126 (e.g., here, in a direction toward the rear roller 102 ) causes rotation of the cam shaft 310 , and thus of the cam 314 . Thus, the cam 314 exerts pressure on the flange 312 , causing motion of the yoke 302 (and thus the front roller 104 ) toward the rear roller 102 .

By rotating the belt tension knob 126 , then, tension of the sanding belt may be decreased or increased, as needed, for a desired removal, adjustment, installation, or re-installation of the sanding belt. In FIG. 4A, a cast stop 402 a is used that prevents the cam 314 from rotating beyond the illustrated point. A corresponding cast stop 402 b (not visible in FIG. 4A, but shown in FIG. 4B) behind the flange 312 and yoke 302 serves to stop a motion of the cam 314 in the reverse direction, so that a full range of motion of the cam 314 is restricted to approximately 90 degrees. Of course, the cast stops 402 a , 402 b may be placed in slightly different positions, to provide for a greater or lesser degree of motion of the cam 314 (and thereby of the front roller 104 ). In other implementations, additional or alternative techniques may be used to restrict a range of motion of the belt tension knob 126 . For example, rotation stops may be placed on an opposite side of the gear housing 214 than that shown in FIG. 4A, e.g., directly in contact with the belt tension knob 126 .

FIG. 4B illustrates a cam shaft assembly for providing the belt tension adjustment mechanism described above. In FIG. 4B, the cam shaft 310 is illustrated as containing grooves 404 a that are mated to, and correspond with, grooves 404 b within the belt tension knob 126 . In this way, rotation of the belt tension knob 126 may cause rotation of the cam shaft 310 , as described above, due to the interaction between the mated grooves 404 a , 404 b.

Further in FIG. 4B, a flange bushing 406 is illustrated that may be inserted into a bore or opening 408 formed in the gear housing 214 , and through which the cam shaft 310 may be inserted. The flange bushing 406 may comprise, for example, Teflon, or any material suitable for allowing rotation of the belt tension knob 126 and cam shaft 310 . A washer 410 , such as, for example, a wave spring washer, may be used on an opposite side of the gear housing 214 , in conjunction with the belt tension knob 126 , in order, for example, to prevent undesired motion of the belt tension knob 126 when tension is off of the cam shaft 310 . The entire assembly may be joined using a screw 412 , inserted through the belt tension knob 126 and into a tapped hole of the cam shaft 310 (not visible in FIG. 4B).

In this way, reliable and easy rotation of the belt tension knob 126 may be maintained during a lifetime of the belt sander 100 . Further, the various components just described may be manufactured and assembled in a quick and cost-effective manner. For example, the cam shaft 310 may be formed using powdered metal, and may be formed near net shape, i.e., may be formed during a manufacturing process that results in the cam shaft 310 having the illustrated form (including the grooves 404 a ), without generally requiring secondary operations on the cam shaft 310 (although secondary operations are not necessarily excluded; for example, as just referenced, a tapped hole at an end of the cam shaft 310 , through which the screw 412 is inserted, may be formed as part of a secondary operation on the camshaft 310 ). For example, injection molding may be used, in which the metal powders are injection molded with a polymer or other binder, which is then removed for fusing of the metal powder into the shape of the cam 314 and cam shaft 310 .

FIGS. 5A-5D illustrate example tracking box designs and implementations for use with the belt sander 100 of FIGS. 1A and 1B. For example, FIG. 5A illustrates the tracking box 108 with a first design for joining the platen 106 of FIGS. 1A and 1B thereto. In FIG. 5A, the platen 106 and the tracking box 108 are shown as platen 106 a and tracking box 108 a , to distinguish the illustrated designs from that of the alternate implementations associated with FIGS. 5B and 5C, below.

In the example of FIG. 5A, then, the tracking box 108 a includes slots 502 , which, as referenced above, may be used for the insertion and mounting of the yoke 302 (not shown in FIG. 5A). The tracking box 108 a also includes slots 504 a and 504 b . As may be appreciated from FIG. 5A, the platen 106 a includes flanges 506 a and 506 b that mate with, e.g., slide into, the respective slots 504 a and 504 b.

More specifically, a cork 508 is used that has a pressure-sensitive or pressure-absorbing adhesive surface for attaching to the platen 106 a . Then, the cork/platen assembly may together be attached to the tracking box 108 a , simply by sliding the flanges 506 a / 506 b into respective receiving slots 504 a / 504 b . With the tracking box 108 a joined to the gear housing 214 on one side, and with the tracking box cover 110 attached to the other (see FIG. 5B for an example of a similar construction), the cork/platen assembly may be maintained therebetween, without requiring screws or other secondary joining techniques to maintain the assembly as a whole.

In some implementations, the tracking box 108 a itself may be formed as an Aluminum extrusion (i.e., metal shaped by flowing through a shaped opening in a die), with the slot 502 for the yoke 302 being machined after the extrusion occurs. The platen 106 a may be, for example, stamped metal, or any other material suitable for applying and withstanding pressure against the sanding belt (and thereby a sanding surface). In this way, the assembly of FIG. 5A may be manufactured in a fast, reliable, and cost-effective manner.

FIGS. 5B and 5C illustrate an alternate implementation of a tracking box for use with the belt sander 100 of FIGS. 1A and 1B. Referring first to FIG. 5B, a substantially similar configuration to FIG. 5A is illustrated, in which the cork board 508 is adhered to the platen 106 b for attachment to the tracking box 108 b (where the latter two elements are so labeled for the purposes of distinguishing from the platen 106 a and the tracking box 108 a , respectively, of FIG. 5A).

In FIG. 5B, however, a slot 510 in the tracking box 108 b is illustrated as matching a substantially triangular-shaped flange 512 of the platen 106 b . FIG. 5C more clearly illustrates a nature of the joining of the triangular flange 512 with the mating slot 510 . Meanwhile, a back edge 514 of the platen 106 b is illustrated as being substantially flat, and extending under and beyond a length of the cork board 508 . FIG. 5B also more fully illustrates a nature of the assembly and joining of the tracking box 108 b and related components with the tracking box cover 110 and the gear housing 214 .

In this way, then, a secure attachment of the cork board/platen assembly to the tracking box 108 b may be obtained, using only the single flange 512 and slot 510 . That is, the triangular shape of the flange 512 (and corresponding shape of the slot 510 ) provide a more secure attachment than would the single, curved flange 506 b and slot 504 b of FIG. 5A (if the latter were used without the rear flange 506 a and slot 504 a ), and, moreover, may provide a more secure attachment in both a front-to-back, as well as side-to-side, direction(s). As a result, for example, the platen 106 b may be secured to the tracking box 108 b , even if a rear portion of the platen 106 b is damaged (e.g., worn through or melted).

Moreover, the design of FIGS. 5B and 5C allows the back edge 514 of the platen 106 b to be freed, for example, for extension thereof toward the rear roller 102 (when assembled). Such extension may improve a balance of the belt sander 100 during operation.

FIG. 5D illustrates a view of the design of FIGS. 5B and 5C in which the tracking box 108 b and associated tracking elements are fully assembled and mounted within the belt sander 100 , but with the tracking cover 110 removed. As shown, and as referenced above with respect to FIGS. 3, 4 A, and 4 B, the yoke 302 may be mounted in the slots 502 and loaded by the springs 314 and 306 . Accordingly, at least the various advantages described herein may be obtained, including, for example, tracking of the sanding belt, easy removal of the sanding belt, and reliable mounting of the platen 106 b.

FIGS. 6A and 6B illustrate a drive mechanism for the belt sander 100 of FIGS. 1A and 1B. Specifically, FIG. 6A illustrates the inclusion of a drive band 602 in/on the rear roller 102 . FIG. 6B illustrates that the rear roller 102 may include a groove 604 to receive the drive band 602 .

In some implementations, the drive band 602 may include rubber (or other elastomer and/or polymer) that provides sufficient friction against the sanding belt that rotation of the rear roller 102 is reliably translated into rotation of the sanding belt around the rear roller 102 and the front roller 104 . In other words, the drive band 602 provides sufficient torque-carrying ability to drive the sanding belt during operation of the belt sander 100 . As a result, the belt sander 100 is provided with a robust, cost-effective drive mechanism.

The rear roller 102 may include a die cast Aluminum wheel with the groove 604 formed therein. In some implementations, the rear roller 102 may be die cast so as to include a crown at a center of the wheel, e.g., at a center of the groove 604 when the groove 604 is centered on the wheel. In these implementations, the drive band 602 may thus protrude slightly above an outer edge(s) of the rear roller 102 , so as to establish improved contact between the drive band 602 and the sanding belt as compared to implementations without the crowning (or other raising of the drive belt 602 relative to the other surface(s) of the rear roller 102 ).

FIG. 7 illustrates an example implementation of the belt sander 100 of FIGS. 1A and 1B that includes a pre-tensioned drive belt. Specifically, FIG. 7 illustrates the drive belt 208 of FIG. 2B, provided around the drive pulley 210 and the driven pulley 212 . As explained above with respect to FIG. 2B, the motor 202 , through gears within the gearbox 206 , causes rotation of the drive pulley 210 . This rotation is translated through the drive belt 208 to the driven pulley 212 , and thereby to rotation of the rear roller 102 (not shown in FIG. 7).

In FIG. 7, the drive belt 208 may include a pre-tensioned drive belt that is fitted around the drive pulley 210 and the driven pulley 212 with a tension selected to allow slippage of the drive belt 208 in response to a selected torque value of the motor 202 . In other words, for example, the drive belt 208 may be pre-tensioned and stretched to fit onto the drive pulley 210 and the driven pulley 212 . Such pre-tensioning may allow the drive belt 208 to settle into an appropriate operating tension quickly and remain at this operating tension.

In addition to consistent driving of the sanding belt, this pre-tensioning allows the slippage referenced above, according to which a certain torque value experienced by the drive belt 208 results in slippage of the belt and corresponding prevention of damage to the motor 202 (e.g., due to lock-up of the motor 202 ) and/or damage to the gears of the gearbox 206 . Thus, the drive belt 208 acts as a clutch during operation of the belt sander 100 , so that, for example, if an object is accidentally sucked into the sanding belt, a jamming of the belt sander 100 is avoided due to the described slippage of the drive belt 208 . This clutch effect may be designed to be sufficient to allow the user to stop the belt sander 100 , e.g., using the on/off switch 116 , so that the user may then remove the object and resume use of the belt sander 100 .

For example, the belt sander 100 may experience an accidental intake of the power cord 120 , such as when the user mistakenly backs over the power cord 120 during operation of the belt sander 100 . In the implementation of FIG. 7, the pre-tensioned drive belt 208 would thus begin to slip as the jammed sanding belt becomes unable to rotate, and an undesirably high level of torque begins to be experienced by the drive belt 208 . During such slipping, as just referenced, the user may shut off the belt sander 100 and remove the power cord 120 (e.g., by rolling the sanding belt backwards), without having to perform any disassembly of the belt sander 100 .

Accordingly, the implementation of FIG. 7 may provide a clutch for the belt sander 100 that slips at a certain load value and prevents motor burn up or other damage (e.g., damage to the gear train), so that a prolonged lifetime of the belt sander 100 is obtained. Further, the described belt design allows for loosened manufacturing tolerances of the fixed center distance dimension of the implementation, while maintaining constant tension on the drive belt 208 . That is, the distance between the drive pulley 210 and the driven pulley 212 may be fixed, as opposed to other designs where some degree of flexibility or motion may be provided for one or both of the drive pulley 210 and/or the driven pulley 212 .

FIGS. 8A-8C illustrate an example implementation of the belt sander 100 of FIGS. 1A and 1B using fitted wear plates 802 , 804 . The wear plates 802 , 804 may be included, for example, to prevent the sanding belt from damaging the gear housing 214 when the sanding belt is tracked too far in a direction of the gear housing 214 .

The wear plates 802 , 804 may be made of, for example, ceramic, and may have an easily and inexpensively-manufactured shape, such as, for example, rectangular or square. As shown in FIG. 8A and explained in more detail below, the wear plates 802 , 804 may be maintained in a desired position by a fastening of the tracking box 108 to the gear housing 214 . In this way, no specialized or expensive fastening elements are required in order to position and use the wear plates 802 , 804 .

In FIG. 8A, a mounting/positioning technique for the wear plates 802 , 804 is illustrated, in which corresponding undercuts 806 , 808 are formed in the gear housing 214 , as shown, so as to provide slots into which the wear plates 802 , 804 may be inserted (shown in more detail in FIG. 8C). That is, the gear housing 214 may be considered to include a topwall 214 a and a sidewall 214 b , so that the undercuts 806 , 808 form slots within the topwall 214 a proximate to a surface of the sidewall 214 b , as shown.

Accordingly, first (e.g., top) ends of the wear plates 802 , 804 may be inserted into the corresponding undercuts 806 , 808 , and partially held in position there by side-locating ribs 810 and 812 . Then, as referenced above and shown more clearly in FIG. 8C, second (e.g., bottom) ends of the wear plates 802 , 804 may be trapped against the sidewall 214 a by the tracking box 108 , e.g., by a screwing of the tracking box 108 to the gear housing 214 .

By trapping each of the wear plates 802 , 804 in at least two places, as shown, and by restricting a sideways motion of the wear plates 802 , 804 with the side-locating ribs 810 , 812 , the wear plates 802 , 804 may reliably be maintained in position and may thus protect the gear housing 214 from damage caused by the sanding belt. Further, the simple assembly provided by the implementations just described may result in a cost reduction associated with avoidance of any additional fasteners and/or assembly methods.

FIGS. 9A-9D illustrate sealing techniques associated with a gear train of the belt sander 100 of FIGS. 1A and 1B. In FIG. 9A, a seal assembly 900 is shown that includes a seal holder 902 , a lip seal 904 contained within (a bore of) the seal holder 902 , and an O-ring 906 within a groove 907 of the seal holder 902 . The seal holder 902 may be, for example, a machined part or a powdered metal part.

As described in more detail below with reference to FIGS. 9B-9D, and by way of example and not limitation, the seal assembly 900 may serve at least two purposes. First, the seal assembly 900 may provide sealing for a lubricant for gears contained within the gearbox 206 , and, second, the seal assembly 900 may provide a point of contact and/or leverage for removing gear elements when servicing the gearbox 206 .

FIG. 9B is an expanded view of an assembly and use of the seal assembly 900 of FIG. 9A. In FIG. 9B two examples of seal assemblies 900 a , 900 b are provided. In a first example, the drive pulley 210 (e.g., a jackshaft associated with the drive pulley 210 ) is inserted through a bearing 908 , and the seal assembly 900 a (lip seal 904 a , seal holder 902 a , and O-ring 906 a ) is then pressed against a gear 910 and a nut 912 that holds the gear 912 in place within the gearbox 906 (shown in more detail in FIG. 9C). Then, the seal assembly 900 a may be maintained in position by screws 914 .

Similarly, on an armature side of the gearbox 206 , associated with the motor 202 , a shaft 916 of an armature assembly is inserted through the seal assembly 900 b (lip seal 904 b , seal holder 902 b , and O-ring 906 b ), and against a pinion 918 of the gear train (shown in more detail in FIG. 9D). Then, screws 920 may be used to secure the seal assembly 900 b against the gear housing 214 /gearbox 206 .

FIG. 9C is a cut-away view of the gearbox 206 illustrating the seal assembly 900 a in the context of the assembled belt sander 100 . In FIG. 9C, the gear 910 may be shown to be in contact with the pinion 918 , so that rotation of the motor 202 may result in corresponding rotation of the jackshaft of the drive pulley 210 , as referenced herein. As should be appreciated from the above discussion, the gear train of FIGS. 9C and 9D illustrates one example that may be used with the belt sander 100 , although, in general, the compact and in-line design of the belt sander 100 may benefit from use of other gear trains, such as, for example, a worm drive or cross-axis helical gear design.

Accordingly, an oil or fluid grease may be used in such gear trains, and the seal assembly 900 a may prevent such oil or fluid grease from leaking from the gearbox 206 . For example, the seal assembly 900 a (and the bearing 908 ) may be inserted into respective bore(s) 922 , and the O-ring 906 a may prevent leakage around an outer edge of the seal assembly 900 a , while the lip seal 904 a may prevent leakage around the jackshaft of the drive pulley 210 .

In the design of FIG. 9C, then, leakage may be minimized or prevented. Meanwhile, to remove the gear 910 , the drive pulley 210 may simply be pulled out, in which case, the bearing 908 and the seal assembly 900 a are simply removed from the bore 922 . More specifically, as appreciated from FIG. 9C, pressure from the gear 910 on the seal assembly 900 a during pulling of the drive pulley 210 may result in easy removal of the bearing 908 and the seal assembly 900 a . That is, a smallest diameter on a flange of the gear 910 may exert pressure on the seal holder 902 a , and may not exert pressure on the lip seal 904 a itself. As a result, damage to the lip seal 904 a may be avoided, and so a need to replace the lip seal 904 a when servicing the gearbox 206 may be reduced or eliminated.

FIG. 9D is a cut-away view of the gearbox 206 illustrating the seal assembly 900 b . In FIG. 9D, many of the same or similar advantages and features just described with respect to FIG. 9C are provided for the armature assembly of the motor 202 . Specifically, for example, the shaft 916 may be inserted through a bearing 924 and through the seal assembly 900 b , and into a bore 926 for joining with the pinion 918 .

Thus, as just described, the seal assembly 900 b prevents leakage of oil or grease from the gearbox 206 . Moreover, during removal of the shaft 916 , a back shoulder of the pinion 918 may contact, and exert pressure on, the seal assembly 900 b , and, more specifically, on the seal holder 902 b . In this way, the shaft 916 may easily be removed, e.g., for servicing, without damaging the lip seal 904 b.

By using the seal assembly 900 that is, in at least some implementations, a slip fit into the same sized bore(s) 922 , 926 of the bearings 908 , 924 , assembly may be performed easily and reliably, and leakage may be prevented. Moreover, disassembly (and subsequent servicing; e.g., replacing of the gear 910 ) may be performed quickly and easily, without damaging the lip seal 904 , thereby facilitating subsequent re-assembly, as well.

FIGS. 10A-10C illustrate a motor brush system for use in the belt sander 100 of FIGS. 1A and 1B. In FIG. 10A, a curved or concave brush card 1002 is illustrated that includes a frame 1004 having a curved shape, e.g., a C-shape or U-shape. As shown, a screw 1006 a maybe inserted through hole 1006 b on the frame 1004 , and then into a hole 1006 c on the motor 202 (or a casing thereof). Thus, the screw 1006 a illustrates a first type of fastener or mounting element for the brush card 1002 , which is easily inserted or removed for mounting or removal of the brush card 1002 itself.

In this way, as should be apparent from FIG. 10A, the brush card 1002 may easily be mounted to, or removed from, the motor 202 . Accordingly, brushes (not shown in FIGS. 10A-10C) may provide electric

2232149	Belt sander	February, 1941	Tautz
2260949	Portable belt sander	October, 1941	Mall
2289481	Portable belt abrading machine	July, 1942	Burleigh
2742741	Tracking mechanism for belt sander	April, 1956	Lars
2783818	Smooth top v-belt and method of making same	March, 1957	Kenny
3312116	Guiding pulley means for belt sander	April, 1967	Blevins
3331165	Electrical connection means for compact belt sander	July, 1967	Blevins
3359689	Tracking means for belt sander	December, 1967	McCarty et al.
3362111	Driving motor means for compact belt sander	January, 1968	Foell et al.
3363367	Dust collection insert means for belt sander	January, 1968	Blevins et al.
3393573	Belt tensioning construction for compact belt sander	July, 1968	Beckering et al.
3431686	HAND-OPERATED,BELT-TYPE SANDING DEVICE FOR WOODWORKING	March, 1969	Bergler
3496679	HAND-HELD RELT SANDER	February, 1970	Dunn	451/355
3566548		March, 1971	Beckering et al.
3682010	PULLEY CONSTRUCTION	August, 1972	Brooks et al.
3757382	BELT DRIVE ASSEMBLY	September, 1973	Brooks et al.
4075523	Plug-in brush cartridge	February, 1978	Lafferty
4115957	Belt centering and replacement mechanism for belt sanders and the like	September, 1978	Porth et al.
4118797	Ultrasonic emulsifier and method	October, 1978	Tarpley
4163167	Electric motor brush holder	July, 1979	Zelt et al.
4177609	Automatic belt centering device	December, 1979	Rameckers et al.
4195449	Portable cutting-tool sharpener	April, 1980	Scarpa
D255319	Portable belt sander	June, 1980	Schultz et al.
4213288	Power transmission device for a power-operated lawn mower	July, 1980	Takeuchi et al.
4242839	High-speed power tool	January, 1981	Armbruster et al.
4305180	Bayonet coupling nut	December, 1981	Schwarts
4316349	Portable abrasive belt finishing machine	February, 1982	Nelson
4334390	Belt sander	June, 1982	Sumerau
4403454	Belt sander	September, 1983	Glore
4411106	Miniature belt grinder	October, 1983	Fleckenstein et al.
4420703	Permanent magnet motor driven window lifter	December, 1983	Adam et al.
4510718	Hull sanding device	April, 1985	Eichenlaub	451/355
4559465	Brush holder assembly for an electric motor	December, 1985	Gagneux
D282078	Bench-type belt sander	January, 1986	House, II
4574531	Self correcting belt tracking mechanism	March, 1986	McCurry
4584797	Sanding device	April, 1986	Wanninkhof et al.
4593220	Brush bearing sub-assembly for electric motor	June, 1986	Cousins et al.
D286737	Belt sander	November, 1986	House, II
4627624	Packing having multiple seal portions	December, 1986	Usui
4638196	Hand-held tool with an electric motor and wearing shells for supporting the same	January, 1987	Kranzler
4673837	Motor brush assembly	June, 1987	Gingerich et al.
4677329	Sub-assembly for electric motor with stator terminal connection means	June, 1987	Secoura
4694616	Removable belt-backing mechanism for a belt sander	September, 1987	Lindberg	451/355
4748353	Hand tool for clockwise and counterclockwise rotations	May, 1988	Klingentein et al.
4896462	Mechanism for belt sanders	January, 1990	Farmerier
4924633	Apparatus for use with stationary belt sander station	May, 1990	Hock et al.
5007205	Tensioner release and mechanism for belt sanders	April, 1991	Farmerie
5251406	Power hand tool with a gearbox casing with sealing washer	October, 1993	Kirm
5319887	Hand sander	June, 1994	Walz et al.
5397952	Brush holder for mechanically commutated electric motors	March, 1995	Decker et al.
5403229	Foot pad extender for a belt sander	April, 1995	Seli
5833524	Dust collection system for a power tool	November, 1998	Satoh et al.
5860854	Belt sander with a lateral drift prevention device	January, 1999	Sakoh et al.
6031313	Brush holder device	February, 2000	Sugai
6048297	Gripper cylinder in a folding apparatus	April, 2000	Lange et al.
6163096	Electrical drive unit	December, 2000	Michenfelder et al.
6174226	Hand-held belt sander	January, 2001	Frech et al.
6206771	Balancer for orbital abrading machine	March, 2001	Lehman
6218746	Cordless multi-purpose high torque generating assembly	April, 2001	Gouge
6419569	Hand-held belt sander	July, 2002	Frech et al.
6494636	Retractable pole apparatus	December, 2002	Mozena
6544112	Belt tracking adjustment means for belt type abrading machine	April, 2003	Fuchs
6617726	Motor gear box	September, 2003	Tsergas
6632128	Angle grinder with electric drive	October, 2003	Berger et al.
6648737	Contour sanding apparatus and kit	November, 2003	Deware
D487008	Belt sander power tool	February, 2004	Andriolo
6688349	Hand planing machine	February, 2004	Razlan et al.
6725892	Router	April, 2004	McDonald et al.
6744170	Brush assembly	June, 2004	Du
D492563	Belt sander	July, 2004	Wright
6758731	Orbital sander	July, 2004	Dutterer
D508833	Planer	August, 2005	Brazeel
7034431	Brush holding plate for an electric motor, corresponding electric motor and assembly method	April, 2006	Kapitza
D520317	Belt sander	May, 2006	Robson
7101274	Method and circuit for inserting a picture into a video picture	September, 2006	Etter et al.
D529775	Belt sander	October, 2006	Leasure
20020009960	Belt sander	January, 2002	Swaddle
20050048883	Dust collection system for a belt sander	March, 2005	Melvin et al.
20050079810	Sanding frame & stand for a belt sander	April, 2005	Melvin et al.
20050146239	Brush holding plate for an electric motor, corresponding electric motor and assembly method	July, 2005	Kapitza
20050264127	Brush holder for an electric-motor driven actuator and an electric-motor driven actuator	December, 2005	Benkert
20050272356	Sanding apparatus	December, 2005	Walker et al.
20050272357	Sanding apparatus	December, 2005	Walker
20060264161	Belt sander	November, 2006	Schnell et al.

DE831648	February, 1952
DE1732411	October, 1956
DE1008066	May, 1957
DE1958046	March, 1967
DEP15772959	January, 1970	Process for preparing 2-oxo-1-pyrrolidine derivatives as intermediates
DE2121182	November, 1971
DE7424571	October, 1974
DE7436615	May, 1976
DE2632184	March, 1977
DEP27095381	October, 1977
DE2841357	April, 1979
DE7907875	July, 1979
DE3147418	June, 1983
DE3390138	July, 1984
DE8520256	October, 1985
DE8520258	October, 1985
DEP35060344	August, 1986
DEP35356367	April, 1987
DE88004651	May, 1988
DE3644390	July, 1988
DE37311573	March, 1989
DEP39205002	December, 1989
DE39204995	January, 1990
DEP38233916	January, 1990
DEP38233924	January, 1990
DEP3919651	January, 1993
DE195132793	February, 1996
DEP44329741	March, 1996
DE195158032	October, 1996
DE3644389	July, 1998
DE197040861	August, 1998
DE197041108	August, 1998
DE198510640	June, 1999
DE49812037	August, 1999
DE20001371	July, 2001
DE40107535	April, 2002
DE059818	June, 2002
DE100020356	July, 2002
DE401096866	July, 2002
DE402058070	November, 2002
DE062572	February, 2003
DE102034893	July, 2003
DE403039940	November, 2003
DE19913020	May, 2004
DE103146954	October, 2004
DE103191739	November, 2004
DE404010474	November, 2004
DE103476973	May, 2005
DE405003188	September, 2005
EP0007172	January, 1980	A belt tracking mechanism e.g. for a belt sander.
EP0088234	September, 1983	Mounting fixture for a portable belt sander
EP0158065	October, 1985	HAND TOOL MACHINE WITH A
EP0168531	January, 1986	Sanding device.
EP0195929	October, 1986	Handtool machine with an electric motor.
EP0479783	April, 1992	HAND SANDER.
EP0472548	August, 1994	PORTABLE TOOL COMPRISING A DRIVE HOUSING WITH PACKING RING.
EP0548782	April, 1997	Hand tool with a dust bag.
EP0851541	July, 1998	Brush holder device
EP0920723	June, 1999	ELECTRIC DRIVE UNIT
EP0935318	August, 1999	Brush assembly
EP1013383	June, 2000	Belt sander cartridge
EP1129822	September, 2001	Orbital sander
EP1175281	January, 2002	ANGLE GRINDER WITH ELECTRIC DRIVE
EP1528656	May, 2005	Brush holder for an electromotive actuator and elektromotive actuator
EP1604780	December, 2005	Sanding apparatus
EP1604781	December, 2005	Belt sander
GB1075904	July, 1967
GB1081736	August, 1967
GB2321865	August, 1998
WO/1988/000110	January, 1998
WO/2005/102603	November, 2005	BELT SANDER WITH SANDING DEPTH REFERENCE MEMBER
WO-2006078966	July, 2006