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Title:
ECCENTRIC SANDING DEVICE
Document Type and Number:
WIPO Patent Application WO/2017/072751
Kind Code:
A1
Abstract:
A sanding device includes a rotatable structure with one or a plurality of resilient extensions that extend outward from a front face of the rotatable structure. A holding structure holds an arch of sandpaper over each resilient extension such that the sandpaper arch covers a distal end of the resilient extension. The sanding device is eccentrically mounted on a rotatable mounting structure.

Inventors:
HAGAY YONATAN (IL)
SPECTOR GAVRIEL (IL)
Application Number:
PCT/IL2016/051101
Publication Date:
May 04, 2017
Filing Date:
October 10, 2016
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
DIMAR LTD (IL)
International Classes:
B24D13/14; B24D13/02
Foreign References:
US4493170A1985-01-15
US5119601A1992-06-09
US5317838A1994-06-07
DE2411749A11975-09-25
EP0922535A11999-06-16
JP3051951B22000-06-12
US7081047B22006-07-25
US8043144B22011-10-25
US20130157548A12013-06-20
US4133146A1979-01-09
US4324017A1982-04-13
US4365448A1982-12-28
Attorney, Agent or Firm:
SIERADZKI, Doron et al. (IL)
Download PDF:
Claims:
P-79142-PC

CLAIMS

1. A sanding device comprising:

a rotatable structure with one or a plurality of resilient extensions that extend outward from a front face of the rotatable structure; and

a holding structure for holding an arch of sandpaper over each of said one or a plurality of resilient extensions such that the sandpaper arch covers a distal end of that resilient extension.

2. The device of claim 1, wherein said one or a plurality of resilient extensions extend substantially perpendicularly from the side of the rotatable structure.

3. The device of claim 1 or 2, wherein a resilient extension of said one or a plurality of resilient extensions comprises a brush.

4. The device of any of claims 1 to 3, wherein the resilient extension is substantially flat.

5. The device of claim 4, wherein a width of the flat resilient extension is oriented substantially radially on the front face of the rotatable structure.

6. The device of any of claims 1 to 5, wherein the rotatable structure comprises a disk.

7. The device of any of claims 1 to 6, comprising a face plate that is separable from the rotatable structure.

8. The device of claim 7, wherein the holding structure comprises two slots in the face plate into which an each end of the sandpaper arch is insertable such that each end is held between the face plate and the rotatable structure when the face plate is tightened against the rotatable structure. P-79142-PC

9. The device of claim 8, wherein the face plate comprises an opening for a resilient extension of said one or a plurality of resilient extensions, the two slots straddling the opening.

10. The device of claim 9, wherein the two slots are substantially parallel to the opening.

11. The device of any of claims 7 to 10, wherein a spring is configured to separate the face plate from the rotatable structure when a screw for holding the face plate to the rotatable structure is loosened.

12. The device of any of claims 1 to 11, further comprising a shaft that extends rearward from the rotatable structure and that is rotatable with the rotatable structure.

13. The device of claim 12, wherein the shaft is eccentrically mounted on a rotatable mounting structure.

14. The device of claim 13, wherein the mounting structure comprises a bearing to enable the shaft to freely rotate relative to the mounting structure.

15. The device of claim 13 or 14, wherein the mounting structure comprises a disk.

16. The device of any of claims 13 to 15, wherein a shaft of the mounting structure is connectable to a rotation mechanism.

17. The device of claim 16, wherein the rotation mechanism comprises a CNC machine.

18. A method for sanding a surface, the method comprising: P-79142-PC with an arch of sandpaper held by a holding structure to cover a distal end of each resilient extension of one or a plurality of resilient extensions that extend from a side of a rotatable structure of a sanding device, rotating the device concurrently with placing the sandpaper arch in contact with the surface.

19. The method of claim 18, wherein rotating the device comprises rotating a mounting structure on which an axis of rotation of the device is eccentrically mounted via a bearing that enables the device to freely rotate with respect to the mounting structure.

20. The method of claim 18 or 19, further comprising operating the holding structure to hold the arch of sandpaper to the rotatable structure.

Description:
ECCENTRIC SANDING DEVICE

FIELD OF THE INVENTION

[0001] The present invention relates to sanding devices.

BACKGROUND OF THE INVENTION

[0002] Wood is often used to make various items and structures whose surfaces are exposed. Such items and structures may include doors, flooring, walls, furniture, cabinets, shelving, chests, utensils, tools and tool handles, toys and decorative items.

[0003] A wood surface that has been cut, carved or otherwise worked is typically rough and may contain splinters. Such a surface, if exposed, may injure skin that comes into contact with the surface, or may snag clothing or fabric. Roughness of the surface may interfere with uniform painting or coating of the surface, with adhesion or other attachment of items or objects to the surface, and may interfere with the stable support of items on the surface.

[0004] Exposed wood surfaces are generally finished by sanding, or by otherwise abrading the surface with a roughened or abrasive tool or surface. Various types of motorized sanders and other finishing tools have been developed for the purpose of eliminating the effort of manual sanding and, in some cases, to enable automated sanding or smoothing of a workpiece. Various types of sanding tools may be designed for a particular use. For example, various types of sanders may be designed primarily for sanding a flat surface, a curved surface, or another type of surface. Some types of sanders may be suitable primarily for use in a plant that mass-produces items.

SUMMARY OF THE INVENTION

[0005] There is thus provided, in accordance with an embodiment of the present invention, a sanding device including: a rotatable structure with one or a plurality of resilient extensions that extend outward from a front face of the rotatable structure; and a holding structure for holding an arch of sandpaper over each of the one or a plurality of resilient extensions such that the sandpaper arch covers a distal end of that resilient extension. P-79142-PC

[0006] Furthermore, in accordance with an embodiment of the present invention, the one or a plurality of resilient extensions extend substantially perpendicularly from the side of the rotatable structure.

[0007] Furthermore, in accordance with an embodiment of the present invention, a resilient extension of the one or a plurality of resilient extensions includes a brush.

[0008] Furthermore, in accordance with an embodiment of the present invention, the resilient extension is substantially flat.

[0009] Furthermore, in accordance with an embodiment of the present invention, a width of the flat resilient extension is oriented substantially radially on the front face of the rotatable structure.

[0010] Furthermore, in accordance with an embodiment of the present invention, the rotatable structure includes a disk.

[0011] Furthermore, in accordance with an embodiment of the present invention, the device includes a face plate that is separable from the rotatable structure.

[0012] Furthermore, in accordance with an embodiment of the present invention, the holding structure includes two slots in the face plate into which an each end of the sandpaper arch is insertable such that each end is held between the face plate and the rotatable structure when the face plate is tightened against the rotatable structure.

[0013] Furthermore, in accordance with an embodiment of the present invention, the face plate includes an opening for a resilient extension of the one or a plurality of resilient extensions, the two slots straddling the opening.

[0014] Furthermore, in accordance with an embodiment of the present invention, the two slots are substantially parallel to the opening.

[0015] Furthermore, in accordance with an embodiment of the present invention, a spring is configured to separate the face plate from the rotatable structure when a screw for holding the face plate to the rotatable structure is loosened.

[0016] Furthermore, in accordance with an embodiment of the present invention, the device includes a shaft that extends rearward from the rotatable structure and that is rotatable with the rotatable structure. P-79142-PC

[0017] Furthermore, in accordance with an embodiment of the present invention, the shaft is eccentrically mounted on a rotatable mounting structure.

[0018] Furthermore, in accordance with an embodiment of the present invention, the mounting structure includes a bearing to enable the shaft to freely rotate relative to the mounting structure.

[0019] Furthermore, in accordance with an embodiment of the present invention, the mounting structure includes a disk.

[0020] Furthermore, in accordance with an embodiment of the present invention, a shaft of the mounting structure is connectable to a rotation mechanism.

[0021] Furthermore, in accordance with an embodiment of the present invention, the rotation mechanism includes a CNC machine.

[0022] There is further provided, in accordance with an embodiment of the present invention, a method for sanding a surface, the method including: with an arch of sandpaper held by a holding structure to cover a distal end of each resilient extension of one or a plurality of resilient extensions that extend from a side of a rotatable structure of a sanding device, rotating the device concurrently with placing the sandpaper arch in contact with the surface.

[0023] Furthermore, in accordance with an embodiment of the present invention, rotating the device includes rotating a mounting structure on which an axis of rotation of the device is eccentrically mounted via a bearing that enables the device to freely rotate with respect to the mounting structure.

[0024] Furthermore, in accordance with an embodiment of the present invention, the method includes operating the holding structure to hold the arch of sandpaper to the rotatable structure.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order for the present invention, to be better understood and for its practical applications to be appreciated, the following Figures are provided and referenced hereafter. It should be noted that the Figures are given as examples only and in no way limit the scope of the invention. Like components are denoted by like reference numerals.

[0026] Fig. 1 schematically illustrates a sanding device, in accordance with an embodiment of the present invention.

[0027] Fig. 2 schematically illustrates components of the sanding device shown in Fig. 1. P-79142-PC

[0028] Fig. 3 schematically illustrates an assembly that includes the sanding device of Fig. 1, eccentrically mounted.

[0029] Fig. 4 schematically illustrates components of the assembly shown in Fig. 3.

[0030] Fig. 5 is a schematic side view of the assembly shown in Fig. 3.

[0031] Fig. 6 is a cross section of the assembly shown in Fig. 5.

[0032] Fig. 7 is a flowchart depicting a method for sanding a surface, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0033] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, modules, units and/or circuits have not been described in detail so as not to obscure the invention.

[0034] Although embodiments of the invention are not limited in this regard, discussions utilizing terms such as, for example, "processing," "computing," "calculating," "determining," "establishing", "analyzing", "checking", or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulates and/or transforms data represented as physical (e.g., electronic) quantities within the computer's registers and/or memories into other data similarly represented as physical quantities within the computer's registers and/or memories or other information non-transitory storage medium (e.g., a memory) that may store instructions to perform operations and/or processes. Although embodiments of the invention are not limited in this regard, the terms "plurality" and "a plurality" as used herein may include, for example, "multiple" or "two or more". The terms "plurality" or "a plurality" may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed simultaneously, at the same point in time, or concurrently. Unless P-79142-PC otherwise indicated, us of the conjunction "or" as used herein is to be understood as inclusive (any or all of the stated options).

[0035] In accordance with an embodiment of the present invention, a sanding device includes a structure that is rotatable about an axis. For example, the rotatable structure may include, or have the form of, a disk. One or more flexible and resilient extensions extend outward from a front face of the rotatable structure. For example, the resilient extension may include a brush, or a slab or array of strips of a flexible and resilient material such as rubber, plastic or a bendable wood. An arch of sandpaper may be placed over each resilient extension such that an abrasive side of the sandpaper faces outward. The rotatable structure includes a holding structure to securely hold the ends of the sandpaper arch over the resilient extension. The holding structure is releasable so as to enable removal of a sandpaper arch from the resilient extension and to enable replacement of a sandpaper arch with another.

[0036] The resilient extensions are sufficiently stiff so as to hold the sandpaper arches outward (forward) from the front face of the rotatable structure toward a surface that is to be sanded. Thus, the sandpaper arches may be prevented from folding over or flapping when the rotatable structure is rotated about its axis. The resilient extensions are sufficiently flexible so as to enable the resilient extensions to bend upon contact with the surface. Thus, as the rotatable structure rotates and the sandpaper arches are pressed onto the surface to be sanded, the resilient extensions may enable the sandpaper surface to adapt to the topography of the surface being sanded. Thus, the sanding device may be capable of sanding carved features of a surface. As the rotatable structure rotates, the resilient extensions may push the sandpaper arch into grooves or other depressions in the wood surface, and into edges along raised features of the wood surface.

[0037] For example, the resilient extensions (e.g., bristles of each of the brushes) may extend outward from a face of the rotatable structure in a direction that is substantially perpendicular to the face of the rotatable structure (e.g., parallel to the axis of rotation of the rotatable structure). The resilient extension may be substantially flat. For example, a brush may be in the form of a flat brush with bristles may be arranged in an elongated pattern. The width of the flat resilient extension (e.g., the elongated dimension of the bristle pattern of a flat brush) may be oriented substantially radially on the face of the rotatable structure.

[0038] The sandpaper arch may be at least as wide as the resilient extension over which it is placed. A distal end of the sandpaper arch covers, and may extend further outward than, the P-79142-PC distal end of the resilient extension over which it is placed. Thus, the sandpaper arch may bend with the resilient extension.

[0039] The structure to hold the sandpaper arch in place on the rotatable structure may include a plate that is held to the front face of the rotatable structure. The plate is partially or completely separable from rotatable structure. The plate includes slits that are positioned on both sides of each resilient extension. Ends of the sandpaper arches may be inserted into the slits. The plate may be tightened against the front face of the rotatable structure to hold the ends of the sandpaper arch between the plate and the rotatable structure. Thus, a sandpaper arch may be securely held so as to cover one of the resilient extensions of the sanding device. For example, one or more screws may be provided for tightening the plate against the front face of the rotatable structure. The screws may be loosened to enable removal or replacement of a sandpaper arch. One or more springs may be provided to push the plate away from the front face when the screws are loosened, thus facilitating replacement of a sandpaper arch.

[0040] Alternatively or in addition, clips or another mechanism may be provided to hold the plate against the front face of the rotatable structure. Alternatively or in addition, the sandpaper arches may be held over the resilient extensions by one or more clips or other mechanisms.

[0041] A distal section of the sandpaper arch near its distal end may include one or more slits. The slits divide the distal end of the sandpaper arch into two or more lateral segments. Dividing the distal end into a plurality of lateral segments may enable each lateral segment to bend differently than an adjacent segment. By enabling different lateral segments of the sandpaper arch to bend by different amounts, the distal end of the sandpaper arch may accommodate itself more exactly to the topography of the surface being sanded. Thus, a sandpaper arch with slits may be capable of sanding finer carved features than a sandpaper arch with fewer or no slits.

[0042] A sanding device, in accordance with an embodiment of the present invention, may be mounted on a rotation mechanism that is configured to rotate the rotatable structure. Such rotation mechanisms may include a handheld drill or a computerized numerical control (CNC) machine. For example, a CNC machine may be programmed to apply the sanding device to an entire surface, or to a region of the surface that includes carved features.

[0043] In some cases, the sanding device may be mounted on the rotation mechanism via an eccentric mounting structure. For example, the mounting structure may include a disk. The axis P-79142-PC of rotation of the rotatable structure of the sanding device is positioned eccentrically on the eccentric mounting structure. The eccentric mounting structure is rotated about the center (axis of rotation) of the eccentric mount by the rotation mechanism Thus, the rotation mechanism may rotate the axis of rotation of the rotatable structure around a center of rotation corresponding to the axis of rotation of the eccentric mounting structure.

[0044] The axis of rotation of the rotatable structure of the sanding device is provided with one or more bearings to enable the rotatable structure to rotate freely about its axis. The combination of eccentric rotation of the axis of rotation of the rotatable structure together with forces between the brushes and sandpaper arches of the sanding device with the surface being sanded, may cause the rotatable structure to rotate. The direction of rotation may be determined

[0045] The eccentric rotation may enable more effective removal of sawdust and chips from the surface than concentric rotation, and may leave fewer marks on the surface.

[0046] Fig. 1 schematically illustrates a sanding device, in accordance with an embodiment of the present invention. Fig. 2 schematically illustrates components of the sanding device shown in Fig. 1.

[0047] Sanding device 10 includes a rotatable sanding structure 12. Although rotatable sanding structure 12 is shown in the form of a circular disk, other forms are possible. For example, a rotatable sanding structure may have a polygonal shape, or may include a plurality of arms that radiate from a central hub.

[0048] Rotatable sanding structure 12 may rotate about its axis of rotation. As shown, the axis of rotation is located substantially at the center of central bore 35. For example, rotatable sanding structure 12 may be directly connected to a shaft of a rotation mechanism that rotates rotatable sanding structure 12 about its axis. In some cases, rotatable sanding structure 12 may be connected to a shaft that is configured to rotate freely about its axis, e.g., when mounted eccentrically on a rotation mechanism. Rotatable sanding structure 12 may include a shaft socket 34 in a central bore 35. Shaft socket 34 may include structure that enables rotatable sanding structure 12 to attach to a shaft in a manner that enables rotation of rotatable sanding structure 12 without disconnecting from the shaft. For example, shaft socket 34 may include one or more indentations other structure that enables a firm connection of rotatable sanding structure 12 to a correspondingly structured shaft of the rotation mechanism. P-79142-PC

[0049] Face plate 14 may be mounted on a side of rotatable sanding structure 12 that is configured to face a surface that is being sanded by sanding device 10. The direction that is faced by face plate 14 when mounted on rotatable sanding structure 12 is herein referred to as the forward direction. The opposite direction is herein referred to as the rearward direction, and any substantially perpendicular direction is herein referred to as a lateral direction. Face plate 14 is at least partially separable from rotatable sanding structure 12 so as to open a gap between face plate 14 and rotatable sanding structure 12. For example, the width of the gap may be no less than the thickness of a sandpaper arch 18.

[0050] A plurality of resilient extensions in the form of brushes 15 extends forward from rotatable sanding structure 12. Alternatively or in addition, some or all of the resilient extensions may have a form other than that of a brush (e.g., a resilient slab or flap, or an array of elongated resilient strips, rods, or other extensions).

[0051] Brush bristles 16 of each brush 15 are mounted on brush base 26. Brush bristles 16 of each brush 15 may extend substantially perpendicularly forward from rotatable sanding structure 12 as shown. Alternatively or in addition, all or some of the brushes or brush bristles may extend in a direction that is slanted at an oblique angle (e.g., smaller than 45°) with respect to the perpendicular. For example, the slants of different brushes may differ from one another.

[0052] Brush bristles 16 of each brush 15 may have a shape that is substantially the same as the shape of a flat brush. Thus, the thickness of brush bristles 16 is much smaller than their width or length. As shown, brush 15 is mounted such that its width is oriented radially on rotatable sanding structure 12. Alternatively or in addition, all or some brushes 15 may be mounted with their widths oriented at an oblique angle (e.g., smaller than 45°) to the radial direction.

[0053] As shown, all brushes 15 are mounted at substantially equal radial distances from the axis of rotation of rotatable sanding structure 12. Alternatively or in addition, different brushes 15 may be mounted at different distances from the axis of rotation.

[0054] Each bristle of brush bristles 16 is sufficiently stiff or resilient to maintain or recover its shape when no bending forces are present, or after a bending force is removed. On the other hand, brush bristles 16 are sufficiently flexible to bend when subjected to a bending force, e.g., due to interaction with a surface that is being sanded. In some cases, brush bristles 16 of a P-79142-PC particular stiffness may be selected in accordance with an intended application (e.g., in accordance with the material or topographical features of a surface to be sanded).

[0055] Brush 15 may be mounted on rotatable sanding structure 12 in a manner that enables replacement of a brush 15. For example, brush 15 may be mounted to rotatable sanding structure 12 by insertion of brush base 26 into brush base slot 17 on rotatable sanding structure 12. Brush bristles 16 extend forward through bristle slot 19 of brush base slot 17. For example, a width of brush base 26 may be at least slightly greater than a thickness of brush bristles 16. Thus, bristle slot 19 may be sufficiently wide to enable brush bristles 16 to extend outward, while retaining brush base 26 within brush base slot 17. When face plate 14 is mounted on rotatable sanding structure 12, brush bristles 16 extend forward via brush slot 20 in face plate 14. In the example shown, each brush base slot 17 is oriented substantially radially, such that the widths of brush bristles 16 of an inserted brush 15 are likewise oriented substantially radially. Alternatively or in addition, all or some of brush base slots 17 may be oriented at an oblique angle to the radial direction.

[0056] Alternatively or in addition, one or more other mechanisms may be provided for holding brush 15 to rotatable sanding structure 12.

[0057] A sandpaper arch 18 may be attached to rotatable sanding structure 12 so as to cover brush bristles 16 of each brush 15. Sandpaper arch 18 may be formed of sandpaper with its rough or sanded side facing outward. Thus, when sanding device 10 is placed against a surface to be sanded, sandpaper arches 18 may be held against the surface by brushes 15. When rotatable sanding structure 12 is rotated while sandpaper arches 18 are held against the surface, the rotational motion may sand the surface.

[0058] Sandpaper arch 18 may conform closely to the shape of brush bristles 16. For example, sandpaper arch 18 may have proximal sides 18a that are straight when mounted over an unbent brush 15. Distal bend 18b (approximately at the middle of sandpaper arch 18) is bent to form arched end 18b.

[0059] Each sandpaper arch 18 may include one or more slits 24 at distal bend 18b. A slit 24 may enable different sections along the width of distal bend 18b to bend by different amounts. During sanding, distal bend 18b is pressed against a topographical feature of a surface being sanded. When the size of the feature is smaller than the width of distal bend 18b, contact with the P-79142-PC feature may bend each section of distal bend 18b by a different amount. Thus, slit 24 may enable distal bend 18b of sandpaper arch 18 to closely conform to the topography of the surface that is being sanded.

[0060] Increasing the number of slits in distal bend 18b may increase the capability of distal bend 18b to conform to a surface feature. However, increasing the number of slits typically results in each section of distal bend 18b covering a smaller number of brush bristles 16. The stiffness of each section increases with the number of brush bristles 16 that are covered by that section. Therefore, the number of slits may be limited to one or another small number in order to ensure that each section of distal bend 18b covers a sufficient number of brush bristles 16 to impart to that section a desired stiffness.

[0061] A holding structure is provided to hold sandpaper arch 18 over a brush 15. For example, each sandpaper arch 18 may be shaped with a proximal foot 18c that is bent (e.g., perpendicularly or otherwise) laterally outward from each proximal side 18a. Proximal foot 18c may be held to rotatable sanding structure 12 by clamping between rotatable sanding structure 12 and face place 14. For example, each proximal end of sandpaper arch 18 (e.g., where proximal side 18a meets proximal foot 18c) may be inserted into sandpaper slot 21 in face plate 14.

[0062] For example, each brush base slot 17 may be straddled by two sandpaper slots 21. The distal end of each sandpaper slot 21 may be open such that one of proximal sides 18a of a sandpaper arch 18 may each be slid in or out of the two sandpaper slots 21. The two sandpaper slots 21 may be oriented substantially parallel to the brush base slot 17 that they straddle. Proximal sides 18a of sandpaper arch 18 may inserted into the two sandpaper slots 21 when a brush base 26 of a brush 15 is inserted into the straddled brush base slot 17. Thus, distal bend 18b of the inserted sandpaper arch 18 may cover, and be oriented parallel to, the distal end of brush bristles 16 of the brush 15 whose brush base 26 is inserted into the straddled brush base slot 17.

[0063] Each proximal foot 18c may extend laterally (e.g., circumferentially) from sandpaper slot 21. Thus, when face plate 14 is held against rotatable sanding structure 12, proximal foot 18c may be held between face plate 14 and rotatable sanding structure 12.

[0064] A mechanism for holding sandpaper arch 18 over brush bristles 16 may be configured to enable or facilitate removal and replacement of sandpaper arch 18. For example, a mechanism P-79142-PC may be provided to facilitate partial or full separation of face plate 14 from rotatable sanding structure 12. Face plate 14 may be held to rotatable sanding structure 12 by a plurality (e.g., three, in the example shown, or another number) of screws 22. For example, each screw 22 may be inserted through a screw hole 25 in face plate 14 and screw hole 23 in rotatable sanding structure 12 and into a corresponding nut 32.

[0065] A spring 30 may be placed over each screw 22, and may be compressed between face plate 14 and rotatable sanding structure 12. Alternatively or in in addition, a spring may be placed elsewhere between face plate 14 and rotatable sanding structure 12. Loosening a screw 22 by partially unscrewing screw 22 from nut 32 may enable spring 30 to expand. The expansion of spring 30 may separate face plate 14 from rotatable sanding structure 12 to form a gap between face plate 14 and rotatable sanding structure 12. If screws 22 are not completely removed, face plate 14 may remain attached to rotatable sanding structure 12.

[0066] When the gap between face plate 14 and rotatable sanding structure 12 is formed, sandpaper arch 18 may be removed from sandpaper slots 21, e.g., by sliding outward via open distal ends of sandpaper slots 21. Similarly, proximal sides 18a of a replacement sandpaper arch 18 may be inserted into sandpaper slots 21. Proximal sides 18a may be inserted into sandpaper slots 21 such that proximal feet 18c are inserted into the gap between face plate 14 and rotatable sanding structure 12.

[0067] After a new or replaced sandpaper arch 18 is fully inserted into sandpaper slots 21, screws 22 may be tightened into nuts 32. When tightened, screws 22 may hold face plate 14 against rotatable sanding structure 12. As a result, proximal feet 18c of sandpaper arch 18 are sandwiched between face plate 14 and sandpaper arch 18, thus impeding or preventing removal of sandpaper arch 18 from sanding device 10.

[0068] Alternatively or in addition, one or both of a rearward-facing surface of face plate 14, a forward- facing surface of rotatable sanding structure 12, or both, may be configured to hold proximal feet 18c, or another part, of sandpaper arch 18 in place. For example, one or both surfaces may be roughened, may be configured with ridges, spikes, or other projections (e.g., with corresponding depressions or indentations on the opposite surface), may be covered with a non-slip material, or may be otherwise configured to assist in holding sandpaper arch 18 in place. P-79142-PC

[0069] Alternatively or in addition, another mechanism may be provided to hold sandpaper arch 18 to sanding device 10. For example, the other mechanism may include one or more clips, clamps, pins, hooks or other structure or mechanisms for holding a sandpaper arch 18 to a rotatable sanding structure 12 of a sanding device 10.

[0070] Sandpaper arches 18 may be provided in a precut and pre-shaped form that is suitable for mounting onto sanding device 10. As another example, sandpaper arches 18 may be provided in a precut form that may be shaped by a user who mounts sandpaper arches 18 on sanding device 10. As another example, sandpaper arches 18 may be cut to a suitable shape by the user from a sheet or roll of sandpaper. In this case, a tool may be provided (e.g., in the form of a press or die) for cutting the sandpaper into a shape that is suitable for use as a sandpaper arch 18.

[0071] In accordance with an embodiment of the present invention, sanding device 10 may be eccentrically mounted in a sanding assembly.

[0072] Fig. 3 schematically illustrates an assembly that includes the sanding device of Fig. 1, eccentrically mounted. Fig. 4 schematically illustrates components of the assembly shown in Fig. 3. Fig. 5 is a schematic side view of the assembly shown in Fig. 3. Fig. 6 is a cross section of the assembly shown in Fig. 5.

[0073] Sanding assembly 40 includes mounting structure 41 onto which sanding device 10 may be eccentrically mounted. Mounting structure 41 may be rotated about its axis. Rotation of mounting structure 41 about its axis causes the axis of a sanding device 10 that is eccentrically mounted on mounting structure 41 to move along a circle that is centered on the axis of mounting structure 41. When operated to sand a surface, a combination of the circular motion of the axis of sanding device 10 and forces exerted by the surface (e.g., friction, normal forces) may cause sanding device 10 to rotate about its axis.

[0074] Mounting structure 41 includes eccentric mounting structure insert 46 that is inserted into mounting structure shell 42. Assembly shaft 44 extends in rearward direction from mounting structure shell 42. Another type of device or structure for eccentrically mounting sanding device 10 may be provided. For example, a mounting structure may have a polygonal shape or may include one or more arms that extend from a central hub.

[0075] Sanding assembly 40 may be operated to sand a surface. For example, sanding assembly 40 may be mounted on a rotation mechanism of a sanding system in the form of, or that includes, P-79142-PC a CNC machine, drill, lathe or other machine or mechanism that is configured or configurable to rotate sanding assembly 40. Typically, the system may be configured to produce, concurrently with rotation of sanding assembly 40, translation of sanding assembly 40 in at least two dimensions relative to a surface to be sanded. For example, the mechanism may include a table or stage on which the surface may be placed and that may be translated relative to the rotation mechanism. Alternatively or in addition, the rotation mechanism may be translatable relative to the surface. For example, the assembly may be configured to move sanding assembly 40 relative to the surface in a two-dimensional pattern that results in sanding of all regions of the surface. In some cases, the system may be configured to produce relative translation in three dimensions. In these cases, sanding assembly 40 may be translated to accommodate a large-scale structure or curving of the surface, or surfaces of different thicknesses or that that are mounted at different elevations relative to other components of the sanding system.

[0076] Sanding device 10 and sanding assembly 40 may be especially suitable for sanding a carved or otherwise structured surface. In some cases, a CNC machine may be programmed to translate sanding assembly 40 to those parts of the surface that include carvings or other structure. In this case, flat portions of the surface may be sanded using an otherwise configured sanding system (e.g., with sanding device 10 replaced by a flat sanding disk).

[0077] Assembly shaft 44 substantially coincides with the axis of rotation of mounting structure 41. Assembly shaft 44 may be mounted, for example, on a chuck or similar holder of a rotation mechanism of a sanding system. Assembly shaft 44 may be mounted substantially at a center of mounting structure shell 42. Thus, mounting structure shell 42 may be rotated substantially symmetrically about its axis.

[0078] Eccentric mounting structure insert 46 is configured to be assembled into cavity 43 of mounting structure shell 42. An orientation of eccentric mounting structure insert 46 relative to mounting structure shell 42 may be fixed by a plurality (e.g., three, or another number) of pins 52. Pins 52 extend from mounting structure shell 42 and may each be inserted into a pin bore 58 of eccentric mounting structure insert 46. Each pin 52 may be provided with a spring 54. For example, spring 54 may enable eccentric mounting structure insert 46 to move longitudinally in or out (e.g., in a frontward or rearward direction) of mounting structure shell 42 to some extent. The longitudinal movement may enable continuous adjustment to a distance between the rotation mechanism and topographical features of a surface that is being sanded. P-79142-PC

[0079] One or more weights may be secured to balance weight holes 53. The weights may be added to enable smooth rotation of mounting structure 41.

[0080] Eccentric mounting structure insert 46 includes eccentric bore 48. Eccentric bore 48 is laterally displaced from assembly shaft 44. Thus, when assembly shaft 44 is rotated by a rotation mechanism of a sanding system, the motion of eccentric bore 48 describes a circle about assembly shaft 44. A particular eccentric mounting structure insert 46 may be selected to be incorporated into mounting structure shell 42 of sanding assembly 40 in accordance with an intended use. For example, a particular eccentric placement of eccentric bore 48 may be suitable for a particular type of surface, type of brush 15 or sandpaper arch 18, speed of rotation, or other characteristic of an intended use.

[0081] Sanding device 10 is mounted to mounting structure 41 via eccentric shaft 56. For example, a frontward facing end of eccentric shaft 56 may in inserted into shaft socket 34 of rotatable sanding structure 12 of sanding device 10. For example, the end of eccentric shaft 56 may have a square or polygonal shape that fits into a correspondingly shaped section of shaft socket 34. When inserted into shaft socket 34, eccentric shaft 56 rotates together with rotatable sanding structure 12 and sanding device 10.

[0082] A rearward facing end of eccentric shaft 56 may be inserted into eccentric bore 48 of mounting structure 41. Eccentric shaft 56 may be held within eccentric bore 48 via shaft bearings 50. Shaft bearings 50 enable eccentric shaft 56 to rotate freely relative to eccentric bore 48 and mounting structure 41. Thus, rotation of sanding device 10 may be governed by the rotation of eccentric shaft 56 in a circular path about assembly shaft 44 and by externally exerted forces. When so governed, a direction and speed of rotation of sanding device 10 may vary during sanding as determined by the shape of a structure that is currently being sanded at each moment.

[0083] Alternatively to bearings that enable free rotation of sanding device 10, mounting structure 41 may include a transmission (e.g., including one or more gears, cams, pulleys, or other transmission structure) to cause sanding device 10 to rotate in a predetermined manner.

[0084] Fig. 7 is a flowchart depicting a method for sanding a surface, in accordance with an embodiment of the present invention.

[0085] It should be understood with respect to any flowchart referenced herein that the division of the illustrated method into discrete operations represented by blocks of the flowchart has been P-79142-PC selected for convenience and clarity only. Alternative division of the illustrated method into discrete operations is possible with equivalent results. Such alternative division of the illustrated method into discrete operations should be understood as representing other embodiments of the illustrated method.

[0086] Similarly, it should be understood that, unless indicated otherwise, the illustrated order of execution of the operations represented by blocks of any flowchart referenced herein has been selected for convenience and clarity only. Operations of the illustrated method may be executed in an alternative order, or concurrently, with equivalent results. Such reordering of operations of the illustrated method should be understood as representing other embodiments of the illustrated method.

[0087] Sanding method 100 may be performed by an operator of a sanding system that includes a rotation mechanism and a sanding device in accordance with an embodiment of the present invention.

[0088] Sanding method 100 may be performed when sandpaper arches are held to a rotatable structure of the device so as to cover resilient extensions that extend in a forward direction from the rotatable structure (block 110). When needed, a holding structure of the device may be manipulated or otherwise operated to enable attachment, holding, or replacing of one or more of the sandpaper arches. For example, ends of the sandpaper arches may be held within slots in a face plate of the structure on either side of each resilient extension when the face plate is tightened against the rotatable structure. As another example, ends of the sandpaper arches may be held by clips or other holding structure.

[0089] The rotatable structure together with the resilient extensions may be rotated by a rotation mechanism while bringing the arched portion of the sandpaper arches into contact with a surface that is to be sanded (block 120). The rotatable structure may be mounted eccentrically on a mounting structure that is rotated by the rotation mechanism. The rotatable structure may be configured to rotate freely relative to the mounting structure. For example, the rotatable structure or mounting structure may be rotated and translated across the surface to be sanded by a CNC machine.

[0090] Different embodiments are disclosed herein. Features of certain embodiments may be combined with features of other embodiments; thus certain embodiments may be combinations P-79142-PC of features of multiple embodiments. The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be appreciated by persons skilled in the art that many modifications, variations, substitutions, changes, and equivalents are possible in light of the above teaching. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

[0091] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.