Rail type sander

Abstract

An orbital sander includes a housing, a drive unit located within the housing, the drive unit having: an electric motor defining an axis of rotation; a drive shaft coupled for common rotation with the motor about a rotation axis; and a fan rotatably coupled to the lower portion of the drive shaft. The fan includes: a main body having a plurality of fan blades; an upper weight and a lower weight for balancing operation of the fan, the upper weight being located on one side of the main body and the lower weight being located on an opposite side of the main body; and an interruption region positioned opposite the lower counterweight wherein the fan blades located within the interruption region have a reduced mass. The orbital sander further includes a base plate for selectively mounting the sanding sheet, the base plate coupled to the lower portion of the drive shaft for orbital rotation about the axis of rotation.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to co-pending U.S. Provisional Patent Application No. 63 / 221,702, filed on July 14, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The utility model relates to a power oscillating tool, and more particularly to a battery-powered orbital sanding machine. Background Art

[0004] Orbital sanders generally include a manually operable housing, a motor supported by the housing, the motor coupled to a drive shaft driven to rotate about a drive axis, and an assembly for mounting a pad for sanding a work surface, the pad being adapted for orbital motion about the drive axis. Depending on the nature of the orbit, such sanders may be used for either rough sanding or fine sanding work. Utility Model Content

[0005] In one aspect, the utility model provides an orbital sander, the orbital sander includes a housing, a drive unit, the drive unit is located in the housing, the drive unit has: an electric motor, the electric motor defines a rotation axis; a drive shaft, the drive shaft is connected to rotate with the electric motor about the rotation axis; and a fan, the fan is rotatably connected to the lower portion of the drive shaft. The fan includes: a body, the body having a plurality of fan blades; an upper counterweight and a lower counterweight for balancing the operation of the fan, the upper counterweight is located on one side of the body, and the lower counterweight is located on the opposite side of the body; and an interruption area, the interruption area is located opposite to the lower counterweight, wherein the fan blades located in the interruption area have a reduced mass. The orbital sander further includes a base plate, the base plate is used to selectively mount a sanding sheet, the base plate is connected to the lower portion of the drive shaft, and is used for orbital rotation about the rotation axis.

[0006] In another aspect, the utility model provides an orbital sander, the orbital sander includes a housing, a drive unit, the drive unit is located in the housing, the drive unit has: an electric motor, the electric motor defines a rotation axis; a drive shaft, the drive shaft is connected to rotate with the electric motor around the rotation axis, the drive shaft has a lower portion; and a fan, the fan is rotatably connected to the lower portion of the drive shaft. The orbital sander further includes a dust collection portion, the dust collection portion is integral with the housing, and is used to partially accommodate a dust collection system. The dust collection system includes: a shroud portion, the shroud portion is used to partially enclose the fan to form a seal between the housing and the fan; the mating interface, the mating interface has a latch for selectively receiving a dust bag attachment; and a latch mechanism, the latch mechanism is used to hook onto the latch to secure the dust bag attachment. The orbital sander further includes a base plate, the base plate is used to selectively mount a sanding sheet, the base plate is connected to the lower portion of the drive shaft, and is used to orbit around the rotation axis.

[0007] On the other hand, the utility model provides an orbital sander, which includes a housing, a drive unit, the drive unit is located in the housing, the drive unit has: an electric motor, the electric motor has a motor shaft extending from the electric motor; a drive shaft, the drive shaft is connected to the electric motor and offset from the motor shaft, the drive shaft defines a rotation axis and includes a lower portion; and a fan, the fan is rotatably connected to the lower portion of the drive shaft. The fan includes: a main body, the main body has a plurality of fan blades; and an upper counterweight and a lower counterweight for balancing the operation of the fan, the upper counterweight is located on one side of the main body, and the lower counterweight is located on the opposite side of the main body. The orbital sander further includes a base plate, the base plate is used to selectively mount a sanding sheet, the base plate is connected to the lower portion of the drive shaft, and is used for orbital rotation around the rotation axis.

[0008] Other features and aspects of the present invention will become apparent by considering the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a stereoscopic view of an orbital sander according to an embodiment of the utility model.

[0010] Figure 2 yes Figure 1 A perspective view of the opposite side of the orbital sander.

[0011] Figure 3 yes Figure 1 to Figure 2 A cross-sectional view of a drive unit of a belt sander.

[0012] Figure 4A yes Figures 1 to 3 A top perspective view of a fan of a drive unit of a belt sander.

[0013] Figure 4B yes Figure 4A A bottom perspective view of a fan.

[0014] Figure 5A yes Figures 1 to 3 A perspective view of the dust collection system of a belt sander.

[0015] Figure 5B yes Figure 5A Exploded view of the dust collection system.

[0016] Fig. 6A yes Figures 1 to 3 An enlarged perspective view of the front clamp of the sander.

[0017] Figure 6B yes Fig. 6A Side view of the front fixture.

[0018] Figure 7 yes Figures 1 to 3 An enlarged side view of a portion of the foam pad of a belt sander.

[0019] Fig. 8A yes Figure 1 to Figure 2 A perspective view of a battery receptacle for a belt sander.

[0020] Figure 8B yes Fig. 8A Magnified side view of the battery receptacle.

[0021] Fig. 9 is used for Figures 1 to 3 A cross-sectional view of an alternative embodiment of a drive unit for a belt sander.

[0022] Before explaining any embodiment of the utility model in detail, it should be understood that the application of the utility model is not limited to the details of the component construction and arrangement set forth in the following description or shown in the following drawings. The utility model can have other embodiments and can be implemented or executed in different ways. In addition, it should be understood that the words and terms used herein are for descriptive purposes and should not be regarded as limiting. DETAILED DESCRIPTION

[0023] Figures 1 to 3 An orbital sander is shown, and in particular, a quarter plate sander 10. The quarter plate sander 10 includes a main housing 14 having a housing that supports a direct drive drive unit 54 ( Figure 3) of the motor housing portion 18. The direct drive unit 54 includes an electric motor 58 and a drive shaft 62 extending along a rotation axis 66 and rotating in response to torque from the electric motor 58. The main housing 14 further includes: a handle portion 22 extending from the motor housing 18 and shaped to be grasped by a user's hand; a battery receptacle 26 for selectively receiving a battery pack 31 ( Figure 8B ) to power the electric motor 58; and a dust collection portion 20 that is integral with the housing 14 and partially houses the dust collection system 120. The handle portion 22 includes: a controller 70 (e.g., a printed circuit board having one or more microprocessors and a plurality of field effect transducers to drive the electric motor 58); a push button switch 32 that is electrically connected to the controller 70 to provide an input signal to the controller 70 to enable and disable the electric motor 58 in response to actuation of the switch 32; and a button 30 that protrudes from the handle portion 22 and can be pressed by a user to actuate the switch 32. Additionally, the handle 22 includes a speed selection switch 34 that is in electrical communication with the controller 70 to selectively change the rotational speed of the electric motor 58.

[0024] The flat bed sander 10 also includes a base plate 46 that supports the main housing 14 and a paper retention system that includes the front clamp 38 and the rear clamp 42. A foam pad 50 is attached to the base plate 46 (e.g., via screws) and supports the sanding sheet 164 ( Figure 7 As shown, the rear clamp 42 is positioned on the side of the housing 14 opposite the dust collecting portion 20 so that the dust collecting portion 20 does not obstruct access to the clamp 42. In some embodiments of the sanding machine 10, the rear clamp 42 can be retained within the groove 43 of the base plate 46 to form only a single contact point between the rear clamp 42 and the base plate 46 to secure the sanding sheet 164.

[0025] Continue to refer Figures 1 to 3, the drive unit 54 includes: a first bearing 74 that supports the top portion of the drive shaft 62 that is retained in the motor housing 18; and a second bearing 78 that supports the lower portion 64 of the drive shaft 62. The second bearing 78 is captured by a base bracket 48 formed on the base plate 46, and the lower portion 64 of the drive shaft 62 is fastened to the base bracket 48 by fasteners 49 (e.g., screws) so that the drive shaft 62 is rotatably coupled to the base bracket 48. The drive unit 54 further includes a plurality of torque absorbers 82 located on the base plate 46. The torque absorbers 82 bend and absorb torque from the electric motor 58 to prevent free rotation about the rotation axis 66. A fan 86 is positioned on the lower portion 64 of the drive shaft 62 between the second bearing 78 and the drive shaft 62 to generate sufficient suction during operation of the sander 10 to draw dust and debris through the plurality of holes 52 in the base plate 46.

[0026] FIG. 4A to FIG. 4BThe fan 86 is shown to include: a body portion 90 having an aperture 94 for receiving the lower portion 64 of the drive shaft 62; a plurality of fan blades 98 disposed generally radially on the body 90 adjacent the outer periphery; an upper counterweight 102 located on one side of the body 90; and a lower counterweight 106 located on an opposite side of the body 90 relative to the side having the upper counterweight 102. The counterweights 102, 106 each include a plurality of holes 104, 108, respectively, for balancing the fan 86 during rotation. Additionally, the center of mass of the fan 86 can be altered by an interruption region 110 located between the fan blades 98 opposite the lower counterweight 106. The interruption region 110 is shown to be defined by ridges 112 having a short height relative to the height of the fan blades 98, which results in a reduced mass relative to the fan blades 98. The ridges 112 may be formed by shortening the height of one or more fan blades in the interruption region 110, or by molding the ridges 112 during the formation of the fan 86. By removing or reducing mass within the interruption region 110, the center of mass of the fan 86 may be calibrated to provide balanced performance of the sander 10. For example, the size of the interruption region (i.e., the number of ridges 112) within the region 110 may be adjusted to reduce vibration or improve overall user control of the sander 10. Furthermore, altering the center of mass of the fan 86 by removing mass or enlarging the region 110 (rather than adding mass) alleviates the need to uniformly increase the mass of both counterweights 102, 106, which may increase cost or change the size of the sander 10. The shortened height of the ridges 112 within the interruption region 110 also has minimal to no effect on the dust collection efficiency of the fan 86, especially when compared to other conventional orbital sanders having fans without interruption regions 110. The height of the illustrated ridges 112 in the interruption region 110 is about 1 millimeter, but other relatively short heights are possible and are contemplated herein.

[0027] Figure 3 and FIG. 5A to FIG. 5B A dust collection system 120 is shown in accordance with an embodiment of the sanding machine 10. The dust collection system 120 includes an upper section 136 and a lower section 140 having an upper shroud portion 132 and a lower shroud portion 134, respectively, which cooperate to form a shroud portion 130 surrounding the fan 86. The lower shroud portion 134 partially encloses the fan blades 98 from the lower side, and the upper shroud portion 132 partially encloses the fan blades 98 from the opposite side. The upper shroud portion 132 has a protrusion or extension 133 that partially encloses one facing side of the fan 86, and the lower shroud portion 134 has a circumferential protrusion or extension 135 that cooperates with the extension 132 to form a seal 160 between the housing 14 and the fan 86.

[0028] The upper section 136 and the lower section 140 can each be fastened together by a plurality of fastening points 152 and / or corresponding form-fitting features 156, 158 located on the respective sections 136, 140. In some embodiments, the fastening points 152 can be connected using conventional fasteners, such as screws, snap-fit ​​devices, or a combination of both. The dust collection system 120 also includes a mating interface 124 that is completely formed by the lower section 140 to selectively receive a dust bag attachment 128. The dust bag 128 can be mounted to the mating interface 124 via a latch mechanism 144 that hooks onto a latch 125 present on a surface of the mating interface 124.

[0029] During operation of the sanding machine 10, the suction force generated by the fan 86 is drawn through the plurality of holes 52 ( Figure 3 ) sucks the dust and directs it into the shroud 130 along the dust path 148. After the dust enters the shroud 130, the dust circulates around the shroud 130 until the dust is ultimately directed along the path 148 through the mating interface 124 and into the dust bag 128 for collection. As the dust circulates in the shroud 130, the seal 160 creates a vacuum effect, so that little or no dust escapes into the housing 14. This vacuum effect within the shroud 130 creates a strong suction force, resulting in higher dust collection efficiency relative to conventional orbital sanders.

[0030] FIG. 6A to FIG. 6B A front clamp 38 according to an embodiment of the sanding machine 10 is shown. The front clamp 38 includes a body 40 having a central portion 41 and wing portions 45a, 45b; and a torsion spring 47 pivotally mounted to a base plate 46 and in contact with the body 40 of the clamp 38. Each of the wing portions 45a, 45b is supported by a corresponding stop feature 51 mounted on the base plate 46. The stop feature 51 is configured to prevent the wing portions 45a, 45b of the clamp body 40 from being moved when installing / removing the sanding sheet 164 ( Figure 7 ). Additionally, the stop feature 51 provides an increased level of rigidity to the clamp 38, thereby increasing the clamping force between the sanding sheet 164 and the clamp 38, resulting in stronger paper retention. Furthermore, in the event that the sander 10 is dropped or misused by a user, the stop feature 51 prevents the wing portions 45a, 45b from bending to the extent that the sander 10 could be damaged.

[0031] refer to Figure 3 , FIG. 6A to FIG. 6B and Figure 7 By biasing the torsion spring 47, the central portion 41 of the front clamp 38 is moved relative to the bottom plate 46 from Fig. 6A , Figure 6B46, and the sanding sheet 164 is secured to the sanding machine 10. Next, the user inserts the sanding sheet 164 under the clamp 38 and lifts the body 40 of the clamp 38 onto the sanding sheet 164 to secure the sanding sheet 164 in the front clamp 38. After securing the sanding sheet 164 in the front clamp 38, the user lifts the rear clamp 42 from the recess 43 in the base plate 46, thereby releasing the rear clamp body 44. Next, the user wraps the sanding sheet 164 around the foam pad 50 and base plate 46 and moves the sanding sheet 164 between the rear clamp body 44 and the base plate 46. Finally, to fully secure the sanding sheet 164, the user moves the rear clamp 42 back into the recess 43 on the base plate 46 to clamp the sanding sheet 164 between the rear body 44 and the base plate 46.

[0032] Figure 7 A foam pad 50 according to an embodiment of the present invention is shown. The foam pad 50 is retained on the bottom of the base plate 46 by a plurality of fasteners (e.g., screws, not shown) and serves as a retention surface for the sanding sheet 164 when the sanding sheet is clamped between the front clamp 38 and the rear clamp 42. The foam pad 50 is configured so that there is a certain degree of overhang 172 relative to the base plate 46. The overhang 172 acts as a barrier or buffer between the base plate 46 and the work surface 168. During flush sanding, i.e., the sanding sheet 164 is pressed directly against the work surface 168, the overhang 172 prevents any scratches or other damage to the work surface 168 that might otherwise occur in surface-to-surface contact between the hard surface of the base plate 46 and the work surface 168. In some embodiments of the sanding machine 10, the foam pad 50 may include overhangs 172 on three sides of the sanding machine 10 to allow for safe contact between the sanding sheet 164 and the work surface 168. The overhang 172 may be 1.5 mm, or greater or less than 1.5 mm.

[0033] FIG. 8A to FIG. 8BA battery receptacle 26 according to an embodiment of the present invention is shown. The battery receptacle 26 is configured such that when a battery pack 31 is mounted to the sanding machine 10, a lower portion 29 of the battery receptacle 26 creates a gap 200 between the battery pack 31 and the battery receptacle 26. In particular, the lower portion 29 defines a plane P that is oriented obliquely relative to the battery pack insertion axis B. Plane P defines an angle A between 0 and 5 degrees with axis B, and in some embodiments, angle A is greater than 5 degrees but less than 10 degrees. In some embodiments, the angle A is 4.9 degrees. In essence, the battery pack 31 is cantilevered from the battery receptacle 26 such that no portion of the battery pack 31 directly contacts the battery receptacle 26 or the motor housing 18. By eliminating direct contact points between the battery pack 31 and the battery receptacle 26, vibrations carried by the motor housing 18 to the battery receptacle 26 during use of the sanding machine 10 are not transmitted to the battery pack 31, at least not in any significant manner. More specifically, this configuration reduces and / or eliminates vibrations of the battery pack 31 due to vibrations between the battery pack 31 and the battery receptacle 26 , which results in a more pleasant experience for the user when operating the sander 10 .

[0034] Fig. 9 Demonstrated for Figures 1 to 3 An alternative drive unit 254 for the sanding machine 10 . Figures 1 to 3Similar components and features of the sanding machine 10 will be used with the addition of "200". The drive unit 254 includes: an electric motor 258 having a motor shaft 259 for rotatably driving the first pulley 255; a second pulley 257, which is rotatably coupled to the drive shaft 262 and parallel to the first pulley 255; and a belt 260, which is tensioned by the first pulley 255 and the second pulley 257, and the belt transfers torque from the motor shaft 259 to the drive shaft 262. The drive unit 254 further includes: a first bearing 274, the first bearing for supporting a top portion of the drive shaft 262 configured to be retained in the motor housing 18; and a second bearing 278, the second bearing for supporting a lower portion 264 of the drive shaft 262. The second bearing 278 is captured by a base bracket 248 formed on the base plate 246, and the lower portion 264 of the drive shaft 262 is fastened to the base bracket 248 by a fastener 249 (e.g., a screw, not shown) so that the drive shaft 262 is coupled to the base bracket 248 for relative rotation. The drive unit 254 also includes a plurality of torque absorbers 282 located on the base plate 246. The torque absorbers 282 bend and absorb torque from the electric motor 258 to prevent free rotation about the rotation axis 266. A fan 286 having a plurality of fan blades 298 is positioned on the lower portion 264 of the drive shaft 262, between the second bearing 278 and the drive shaft 262, to generate sufficient suction during operation of the sanding machine 210 to suck in dust and debris through the plurality of holes 252 in the base plate 246. To help balance the fan 298 during operation, the fan 298 includes a top counterweight 302 and a bottom counterweight 306. In some embodiments of the drive unit 254 , the fan 298 includes fan blades 298 on both the top side and the bottom side of the fan 298 .

[0035] In some cases, implementing the drive unit 254 in the sander 10 is advantageous because the orientation of the drive unit 254 repositions the center of gravity 400 of the sander 10 closer to the center of the base plate 246 relative to a conventional orbital sander having a direct drive system. Because the center of gravity is located further inward from the edge of the base plate 46, the sander 10 is less likely to tip over when the battery pack 31 is mounted on the battery receptacle 26. Additionally, by positioning the electric motor 258 offset from the drive shaft 262, the sander 10 feels more balanced during use than with a conventional direct drive orbital sander. Furthermore, the drive unit 254 allows a user to customize the gear ratio of the pulleys 255, 257 to ensure maximum efficiency of the selected size and type of electric motor 258. For example, a user can customize the gear ratio of the pulleys 255, 257 so that the drive unit 254 is more efficient than a comparable direct drive sander using an electric motor of the same size and type. Thus, the belt drive unit 254 enables a similarly sized orbital sander to have a longer runtime than a similarly sized direct drive orbital sander.

[0036] Various features of the invention are set forth in the appended claims.

Claims

1. An orbital sander, characterized in that: include: case; A drive unit, the drive unit is located in the housing, and the drive unit comprises: an electric motor defining an axis of rotation, a drive shaft coupled for common rotation with the electric motor about the rotational axis, the drive shaft comprising a lower portion, and a fan rotatably coupled to a lower portion of the drive shaft, the fan comprising: a main body having a plurality of fan blades, an upper counterweight and a lower counterweight for balancing the operation of the fan, the upper counterweight being located on one side of the body and the lower counterweight being located on an opposite side of the body, and an interruption region located opposite the lower counterweight, wherein the fan blades located within the interruption region have a reduced mass; and A base plate for selectively mounting a sanding sheet is coupled to the lower portion of the drive shaft for orbital rotation about the rotational axis.

2. The orbital sander of claim 1, further comprising: a motor housing, the motor housing being used to accommodate the electric motor; a battery receptacle for selectively receiving a battery pack to provide power to the electric motor; as well as A dust collecting portion is integral with the housing and is used to partially house a dust collecting system.

3. The orbital sander of claim 2, further comprising: A paper retention system, the paper retention system comprising: a front clamp supported on the base plate; and A rear clamp is supported on a side of the base plate opposite the dust collecting portion.

4. The orbital sander of claim 1, wherein: The fan blades located in the interruption area have a height of 1 mm.

5. The orbital sander of claim 2, wherein: The dust collection system includes a shroud portion for partially enclosing the fan blades to form a seal between the housing and the fan blades, and a mating interface having a latch for selectively receiving a dust bag attachment.

6. The orbital sander of claim 5, wherein: The dust collection system further includes a latch mechanism that hooks to the latch on the mating interface to selectively secure the dust bag attachment.

7. The orbital sander of claim 3, wherein: The paper retention system further includes one or more stop features mounted to the base plate for preventing the front clamp from bending.

8. The orbital sander of claim 2, wherein: The battery receptacle defines a battery insertion axis, and wherein the battery receptacle includes a lower portion defining a plane oriented obliquely relative to the battery insertion axis to create a gap between the battery pack and the battery receptacle when the battery pack is installed in the battery receptacle, the plane defining an angle between 0 degrees and 10 degrees with the battery insertion axis.

9. An orbital sander, characterized in that: include: case; A drive unit, the drive unit is located in the housing, and the drive unit comprises: an electric motor defining an axis of rotation, a drive shaft coupled for common rotation with the electric motor about the rotational axis, the drive shaft comprising a lower portion, and a fan rotatably coupled to a lower portion of the drive shaft; and a dust collecting portion, the dust collecting portion being integral with the housing and being adapted to partially house a dust collecting system, the dust collecting system comprising: a shroud portion for partially enclosing the fan to form a seal between the housing and the fan, a mating interface having a latch for selectively receiving a dust bag accessory, and a latch mechanism for hooking onto the latch to secure the dust bag attachment; and A base plate for selectively mounting a sanding sheet is coupled to the lower portion of the drive shaft for orbital rotation about the rotational axis.

10. The orbital sander of claim 9, wherein: The seal creates a vacuum effect, thereby directing dust particles along a dust path through the mating interface and into the dust bag attachment.

11. The orbital sander of claim 9, further comprising: a motor housing for accommodating the electric motor; and A battery receptacle is used to selectively receive a battery pack to provide power to the electric motor.

12. The orbital sander of claim 9, further comprising: A paper retention system, the paper retention system comprising: a front clamp supported on the base plate, and A rear clamp is supported on a side of the base plate opposite the dust collecting portion.

13. The orbital sander of claim 9, wherein: The fan further includes: a body having a plurality of fan blades; an upper counterweight and a lower counterweight for balancing the operation of the fan, the upper counterweight being located on one side of the body and the lower counterweight being located on an opposite side of the body; and an interruption region positioned opposite the lower counterweight and wherein the fan blades located within the region have a reduced mass.

14. The orbital sander of claim 12, further comprising a foam pad attached to the base plate for supporting the sanding sheet, wherein The foam pad extends beyond one or more sides of the base plate to act as a buffer between the base plate and the work surface.

15. The orbital sander of claim 13, wherein: The fan blades located in the interruption area have a height of 1 mm.

16. An orbital sander, characterized in that: include: case; A drive unit, the drive unit is located in the housing, and the drive unit comprises: an electric motor having a motor shaft extending therefrom, a drive shaft coupled to the electric motor and offset from the motor shaft, the drive shaft defining an axis of rotation and including a lower portion, and a fan rotatably coupled to a lower portion of the drive shaft, the fan comprising: a main body having a plurality of fan blades; an upper counterweight and a lower counterweight for balancing the operation of the fan, the upper counterweight being located on one side of the body and the lower counterweight being located on an opposite side of the body; and A base plate for selectively mounting a sanding sheet is coupled to the lower portion of the drive shaft for orbital rotation about the rotational axis.

17. The orbital sander of claim 16, further comprising a first pulley rotatably driven by the motor shaft; a second pulley coupled to the drive shaft and oriented parallel to the first pulley; and A belt extends between the first pulley and the second pulley for transmitting torque from the motor shaft to the drive shaft.

18. The orbital sander of claim 16, wherein: The fan further includes an interruption region located opposite the lower counterweight, and wherein the fan blades located within the interruption region have a reduced mass.

19. The orbital sander of claim 16, further comprising: a motor housing for accommodating the electric motor; and A battery receptacle is used to selectively receive a battery pack to provide power to the electric motor.

20. The orbital sander of claim 19, wherein: When the battery pack is mounted to the battery receptacle, the center of gravity is located substantially above the center of the base plate.

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