ATTACHMENT HUB, BACKUP PAD, AND ABRASIVE DISC

Abstract

The present invention relates to an attachment hub for attachment to a sander, comprising a quick-release attachment assembly configured for releasable and aligned engagement with a counterpart of a backup pad particularly for an abrasive disc. Furthermore, the invention relates to a backup pad having a disc-like shape and comprising a first major surface and a second major surface, the first major surface configured for direct or indirect attachment of an abrasive disc, and the second major surface configured for facing towards an attachment hub for attachment to a sander, and a mounting portion for aligned engagement with an attachment hub of a sander.

Claims

1. An attachment hub for attachment to a sander, comprising a quick-release attachment assembly configured for releasable and aligned engagement with a counterpart of a backup pad particularly for an abrasive disc.

2. The attachment hub of claim 1, wherein the attachment hub comprises a hub portion and a frame, the hub portion being adapted for releasable attachment to the sander, the frame having a truss configuration forming an outer perimeter of the attachment hub, and the quick-release attachment assembly being mounted to the frame.

3. The attachment hub of claim 1, wherein the quick-release attachment assembly comprises an actuator, wherein actuation of the actuator results in disengagement of the attachment hub from the counterpart, wherein optionally the actuator comprises a button, and wherein the quick-release attachment assembly is adapted to disengage from the counterpart upon a user pressing the button.

4. The attachment hub of claim 1, wherein the quick-release attachment assembly is configured for axial coupling with the counterpart and wherein the attachment hub comprises one or more protrusions and/or one or more recesses configured for rotational coupling of the attachment hub with the counterpart.

5. The attachment hub of claim 1, wherein the quick-release attachment assembly comprises at least one spring member, wherein optionally: the at least one spring member comprises an engagement portion configured for engagement with the counterpart, and/or the at least one spring member is configured for radial movement, wherein radial outward movement of the at least one spring member causes the quick-release attachment assembly to disengage from the counterpart, and/or the actuator is adapted to be moved along an axial direction and the spring member is adapted to be moved in a radial direction, wherein the movement of the actuator in the axial direction causes the at least one spring member to move in the radial direction, wherein further optionally the actuator comprises a first tapered surface and the at least one spring member comprises a corresponding second tapered surface that is inversely tapered relative to the first tapered surface, wherein the first and second tapered surfaces are slidable relative to each other so that actuation of the actuator results in a transmission of the actuator's movement in the axial direction into the at least one spring member's movement in the radial direction.

6. The attachment hub of claim 5, wherein the at least one spring member comprises a straight section oriented radially within a space of the frame, the engagement portion being formed at the radially outer end section of the straight section, and the straight section being connected to one or more truss elements of the frame, wherein optionally the straight section is connected to the frame by a plurality of bent elements that bias the engagement portion towards an engaged position.

7. The attachment hub of claim 5, wherein the hub portion, at least one spring member and the frame are integrally formed, optionally from a plastic material.

8. The attachment hub of claim 6, wherein the at least one spring member comprises several spring members, each of the spring members extending in a radial direction from a radially inner portion to a radially outer portion and having the engagement portion arranged at the radially outer portion, wherein each engagement portion is configured for engagement with the counterpart, and wherein the spring members are evenly circumferentially distributed.

9. A backup pad having a disc-like shape and comprising: a first major surface and a second major surface, the first major surface configured for direct or indirect attachment of an abrasive disc, and the second major surface configured for facing towards an attachment hub for attachment to a sander, and a mounting portion for aligned engagement with an attachment hub of a sander.

10. The backup pad of claim 9, wherein the backup pad comprises the supporting frame and the foam pad, and wherein the foam pad is located between the first major surface and the supporting frame, and wherein the supporting frame is located between the foam pad and the second major surface, the foam pad preferably providing the first major surface.

11. The backup pad of claim 9, further comprising an access for an actuator of the attachment hub, wherein the access is preferably a central through hole.

12. The backup pad of claim 9, wherein the mounting part is a counterpart to a quick-release attachment assembly, wherein the counterpart comprises one or more recesses, undercuts, a rim, a groove, or any combination thereof, extending at least partially around a circumference of the pad.

13. The backup pad of claim 9, wherein the backup pad comprises a quick-release attachment assembly configured for releasable and aligned engagement with a counterpart on the attachment hub, wherein the quick-release attachment assembly comprises an actuator, wherein actuation of the actuator results in disengagement of the backup pad from the counterpart on the attachment hub, wherein optionally the actuator comprises a button, and wherein the quick-release attachment assembly is adapted to disengage from the counterpart on the attachment hub upon a user pressing the button.

14. The backup pad of claim 12, wherein the quick-release attachment assembly comprises at least one spring member, the spring member optionally including an engagement portion configured for engagement with the counterpart on the attachment hub.

15. The backup pad of claim 9, wherein the quick-release attachment assembly is configured for axial coupling with the respective counterpart and wherein the backup pad comprises one or more protrusions and/or one or more recesses configured for rotational coupling of the backup pad with the attachment hub.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Specific embodiments of the invention will be described in further detail with reference to the figures.

[0074] FIG. 1 shows a sander attachment system according to the invention;

[0075] FIG. 2A shows an inventive backup pad from a first side;

[0076] FIG. 2B shows the inventive backup pad of FIG. 2A from a second side;

[0077] FIG. 3A shows an inventive attachment hub from a first side;

[0078] FIG. 3B shows the inventive attachment hub of FIG. 3A from a second side;

[0079] FIG. 4A shows a cross-section of detail of the attachment hub of FIGS. 3A and 3B;

[0080] FIG. 4B shows the detail of the attachment hub of FIG. 4A in a top view.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0081] FIG. 1 shows a sander attachment system 2 according to the invention. It includes a backup pad 4 and an attachment hub 6 for attachment to a sander 8. The backup pad 4 has a disc-like shape, preferably with an essentially circular circumference, and has a first major surface 6a and a second major surface 4b. The first major surface 4a is configured for facing towards an abrasive disc 10, and the second major surface 4b is configured for facing towards the attachment hub 6.

[0082] According to the invention, one of the attachment hub 6 and the backup pad 4 comprises a quick-release attachment assembly configured for releasable, and optionally aligned, engagement with the counterpart on the other one of the attachment hub 6 and the backup pad 4. As shown in the embodiment shown in the figures, the attachment hub 6 may comprise the quick-release attachment assembly 12 and the backup pad 4 may comprise a mounting portion 17 for aligned engagement with the attachment hub 6, the mounting portion 17 serving as the counterpart 14 (see also FIGS. 2A and 2B). The dashed line in FIG. 1 indicates a common axis for attachment of the backup pad 4, the attachment hub 6 and the abrasive disc 10 to the sander 8.

[0083] FIG. 2A shows a first side, i.e. the first major surface 4a, of the backup pad 4. FIG. 2B shows a second side, i.e. the second major surface 4b opposite to the first major surface 4a of the backup pad 4. As shown in FIG. 2B, the backup pad 4 may comprise a supporting frame 15 and a foam pad 16. As shown, the foam pad 16 is preferably located between the first major surface 4a and the supporting frame 15 and thus provides the first major surface 4a. The supporting frame 15 is preferably located between the foam pad 16 and the second major surface 4b.

[0084] The backup pad 4 may comprise a fastener component (not shown) for releasable attachment of the abrasive disc 10. The fastener component may be an adhesive, the hooks and/or the loops of a hook and loop fastener, another mechanical fastening system or a component thereof, or any combination thereof.

[0085] As shown in FIGS. 4A and 4B, the attachment hub 6 may comprise a hub portion 18 and a frame 20. The hub portion 18 is adapted for releasable attachment to the sander 8. As shown, the frame 20 preferably has a truss configuration and forms an outer perimeter 22 of the attachment hub 6. The quick-release attachment assembly 12 is mounted to the frame 20.

[0086] In the shown embodiment, the quick-release attachment assembly 12 comprises an actuator 24. Actuation of the actuator 24 results in disengagement of the attachment hub 6 from the counterpart 14.

[0087] Preferably, as illustrated in the figures, the actuator 24 comprises button 24a and the quick-release attachment assembly 12 is adapted to disengage from the counterpart 14 upon a user pressing the button 24a.

[0088] As shown in FIGS. 2A and 2B, the backup pad 4 preferably comprises an access 26 for receiving the actuator 24 of the attachment hub 6, or at least a portion of the actuator 24 such as the button 24a. When the backup pad 4 is attached to the attachment hub 6, the actuator 24 extends from the side of the second major surface 4B through the backup pad 4 towards and optionally beyond the first major surface 4a of the backup pad 4.

[0089] As also shown in FIG. 2A and 2B, the counterpart 14 of the backup pad 4 may be a circumferential undercut. However, it is also contemplated that the counterpart 14 comprises one or more recesses, undercuts, rims, grooves, or any combination thereof, extending at least partially around a circumference of the backup pad 4.

[0090] The quick-release attachment assembly 12 comprises an engagement portion 28 configured for engagement with the counterpart 14.

[0091] As can be seen in FIGS. 3A and 3B, the quick-release attachment assembly 12 preferably comprises at least one spring member 30, and more preferably a plurality of spring members 30. Preferably, each of the at least one spring member 30 comprises an engagement portion 28. Each of the engagement portions 28 corresponds to the respective portion of the counterpart 14, i.e. the mounting portion 17 in the form of an undercut.

[0092] Via the engagement between the one or more engagement portions 28 with the counterpart 14 the attachment hub 6 may be coupled with the backup pad 4. This coupling via the counterpart 14 and the one or more engagement portions 28 may be an axial coupling, i.e. the quick-release attachment assembly 12 may be configured for axial coupling with the counterpart 14.

[0093] As shown in FIGS. 2A to 3B, the attachment hub 6 may comprise one or more protrusions 32 and/or one or more recesses 34 configured for rotational coupling of the attachment hub 6 with the counterpart 14. The backup pad 4 comprises corresponding recesses 34 and protrusions 32. In the attached configuration, i.e. when the backup pad 4 is attached to the attachment hub 6, the protrusions 32 of the backup pad 4 are engaged with the recesses 34 of the attachment hub 6 and the protrusions 32 of the attachment hub 6 are engaged with the recesses 34 of the backup pad 4. A rotation of the attachment hub 6 during operation of the sander 8 will be transmitted to the backup pad 4 via the protrusions 32 and the recesses 34.

[0094] The specific coupling mechanism between the attachment hub 6 and the backup pad 4 may be implemented in a number of different ways. A preferred embodiment is explained with reference to FIGS. 3A to 4B. In the shown embodiment, each spring member 30 comprises a straight section 36 oriented generally radially within a space of the frame 20. The engagement portions 28 are formed at respective radially outer end sections of straight sections 36. Particularly, the straight sections 36 are connected to the frame 20 by a plurality of end elements 38. Preferably, the straight sections 36 are connected to one or more truss elements of the frame 20. Each end element 38 biases the corresponding engagement portion 28 towards an engaged position.

[0095] The spring members 30 are configured for radial movement, as indicated by arrows. A radial outward movement of the spring members 30 causes the attached quick-release attachment assembly 12 to disengage from the counterpart 14 such that the attachment 6 and the backup pad 4 may be separated from one another. In this case, the engaged position is radially inward as compared to a release position. However, it is also possible that a radial inward movement of one or more of the spring members 30 causes the attached quick-release attachment assembly 12 to disengage from the counterpart 14. In this case, the engaged position is radially outward as compared to a release position.

[0096] Each of the spring members 30 preferably comprises a plastic material or is made of a plastic material. The plastic material may be selected from polyamide, polypropylene, ABS, HDPE, acetal, polyester or any combination thereof Additionally or alternatively, the hub portion 18 and/or the frame 20 are formed from a plastic material, preferably from the same material as the spring members 30. The hub portion, the at least one spring member 30 and the frame 20 are integrally formed, for example by injection molding.

[0097] As shown in FIG. 4A, the actuator 24 may be adapted to be moved along a first direction, such as an axial direction, and the at least one spring member 30 may be adapted to be moved in a second direction, such as a radial direction, wherein the movement of the actuator 24 in the first direction causes the at least one spring member 30 to move in the second direction. Such transmission of the movement of the actuator 24 to the movement of the at least one spring member 30 may be achieved in several different ways. A preferred embodiment is shown in FIG. 4A. The actuator 24 comprises a first tapered surface 40 and each of the spring members 30 comprises a corresponding second tapered surface 42. The second tapered surface 42 is inversely tapered relative to the first tapered surface 40. The first and second tapered surfaces 40, 42 are slidable relative to each other and oriented such that actuation of the actuator 24 results in a transmission of the actuator's movement in the axial direction into the at least one spring member's movement in the radial direction. Particularly, pushing the actuator 24 in a downward direction in FIG. 4A causes the first tapered surface 40 to slide along the second tapered surface 42, thereby pushing on the second tapered surface 42 in a radially outward direction, which results in a radially outward movement of the second tapered surface 42 (to the left in FIG. 4 a). As the second tapered surface 42 is a surface of the spring member 30, the spring member 30 including the engagement portion 28 moves radially outward towards the disengaged position.

[0098] Hence, the backup pad 4 may be removed from the attachment hub 6 by actuation of the actuator 24, which results in a movement of the spring members 30 and the engagement portions 28 into the disengaged position. The backup pad 4 including the abrasive disc 10 may then be removed. The same backup pad 4 or another backup pad 4 may be attached to the attachment hub 6 by pushing the backup pad 4 in the correct orientation onto the attachment hub 6 and simultaneously pressing actuating the actuator to move the spring members 30 into the disengaged position. After having the backup pad 4 placed on the attachment hub 6, the actuator 24 may be actuated such that the spring members 30 and the engagement portions 28 return to the engaged position. This causes the engagement of the attachment hub 6 with the backup pad 4. Alternatively or additionally, each spring member 30, preferably each engagement portion 28, may comprise one or more third tapered surfaces 44 and the counterpart 14 may comprise a fourth tapered surface 46 corresponding to the third tapered surface(s) 44. The working principle is analogous to the first and second tapered surfaces 40, 42. Pushing the backup pad 4 against the attachment hub causes the fourth tapered surface(s) 46 to push against the third tapered surfaces 44. This causes third tapered surfaces 44 and thus the spring members 30 to move into the disengaged position until the third and fourth surfaces 44, 46 have passed each other and the spring members 30 return into the engaged position, thus causing the backup pad 4 to snap into engagement with the attachment hub 6.

[0099] The backup pad 4 is shown to comprise dust extraction holes 48 extending from the first major surface 4a through the backup pad to the second major surface 4b. The dust extraction holes 48 contribute to removal of dust generated during sanding of an object with the inventive system. For the dust extraction holes 48 to be effective, they are preferably configured for alignment with corresponding dust extraction holes 49 on the abrasive disc 10.

[0100] As shown in FIG. 2B, the backup pad 4 may comprise one or more pockets or cavities 50. The cavities 50 are preferably arranged in the supporting frame 15 and contribute to a reduction of mass of the backup pad 4. The reduced mass of the backup pad 4 contributes to a reduction of load transferred to the hand and arm of a user. The open truss configuration of the frame and spring member(s) of the attachment hub and the cutouts in the backup pad aid in dust extraction and require no rotational alignment of the backup pad with the frame.