TECHNICAL FIELD

The invention relates to a device for use when a power tool attachment head is attached to a power tool.

BACKGROUND OF THE INVENTION

Power tools having rotating heads can create significant vibrations during use. The vibrations are created as the power tool attachment rotates, as it moves across an uneven surface and/or as the user applies different degrees of pressure on the power tool. For example, brush attachments and rotating cutting heads attached to angle grinders, power tools with rotating buffing heads attached, orbital sanders and the like are known to generate significant vibrations during use. The vibrations created in the power tool attachment are transferred to the body of the power tool, which is gripped by a user. Consequently, the vibrations of the power tool are transferred to the user holding the tool and typically tend to travel up the arm(s) of the user. After prolonged use, the vibrations cause fatigue in the person's arms. In some cases, the fatigue prevents the person from using the power tool until he or she has recovered, which can cause delays at the worksite.

The invention of United States patent no. 4,449,329 aims to dampen the vibrations produced by an angle grinder during use. The invention provides a composite washer used to provide a soft mount for a tool element subassembly mounted on the output spindle of a power tool. The composite washer is formed from a pair of metal washers separated by a softer material (such as thermoplastic polyurethane resin) that is moulded to the washers. The softer material fills a space between the washers and also covers inner edges of the washers that surround the spindle of an angle grinder. The washer is attached to a power tool by sliding the washer onto the output spindle of the power tool before a power tool attachment is attached to the spindle.

A drawback of the composite washer of US 4,449,329 is that it can easily fall off the output spindle when the head of the angle grinder is being changed. Furthermore, the composite washer and the head of the power tool need to be attached to the angle grinder in two separate steps. In addition, if the softer material of the composite washer starts to deteriorate, the entire device must be discarded, which is wasteful and costly.

Another problem relating to power tools is that power tool attachment heads typically comprise a metal body or a metal portion that presses against the metal body of a power tool when attached to the power tool. The metal to metal contact between the power tool and attachment can cause the two articles to lock or jam together when the power tool has been used. It can then be difficult to detach the power tool attachment from the power tool. Sometimes it may be necessary to use a tool, such as a wrench, to detach the power tool attachment from the power tool body,

It is therefore an object of the invention to provide a vibration absorbing device and/or an anti-lock device for a power tool that goes at least some way toward overcoming one or more disadvantages of the prior art, or that at least provides a useful alternative.

SUMMARY OF THE INVENTION

The device of the invention may be used for absorbing vibrations from power tools, such as brush attachments on angle grinders, electrical sanders, and the like. The device may also be used to provide anti-lock/anti-grab properties.

In a first aspect, the invention provides a device for use with a power tool, the device comprising: a retainer comprising opposing first surface and second surfaces and a bore extending between the first and second surfaces; and a compression member attached to the retainer, wherein a first surface of the compression member extends beyond the first surface of the retainer.

Preferably, the first surface of the retainer comprises a recess surrounding the bore and wherein at least one lip projects from an outer periphery of the recess toward the bore to partially cover at least a portion of the recess. The at least one lip may be substantially continuous around the outer periphery of the recess. Alternatively, two or more lips are spaced equidistant around the outer periphery of the recess,

In one form, the recess substantially surrounds the bore of the retainer.

In one form, the compression member comprises a second surface substantially opposing the first surface of the compression member and also comprises a centrally located aperture. The aperture extends between the first and second surfaces of the compression member and substantially aligns with the bore of the retainer. The compression member also comprises an outer wall from which at least one flange projects.

Preferably, the compression member is located within the recess of the retainer such that the at least one flange of the compression member is held beneath the lip of the retainer. More preferably, the at least one flange extends around the entire periphery of the compression member. In one form, at least two flanges are provided on opposing sides of the compression member. Alternatively, the compression member comprises three or more flanges spaced equidistant around the outer wall of the compression member.

In one form, the recess is a circular recess and the compression member is in the shape of a ring and is dimensioned to fit within the recess so that the bore of the compression member substantially aligns with the bore of the retainer.

Optionally, the compression member comprises a plurality of recesses or apertures formed in the outer wall and/or an opposing inner wall of the compression member. In one form, a plurality of recesses and/or apertures are formed in the first and/or second wall of the compression member.

The compression member may be made of polyurethane.

In one form, the device of the invention also comprises a shaft that extends from the second surface of the retainer and comprises a centrally located bore that extends along the length of the shaft and substantially aligns with the bore of the retainer.

Optionally, the surface of the bore of the shaft and/or retainer is polyurethane.

Preferably, the bore of the shaft and/or retainer has a threaded surface.

In a second aspect, the invention provides a power tool attachment head comprising a device according to the first aspect of the invention. In one form, the attachment head is a brush attachment.

In a third aspect, the invention provides a retainer for a device according to the first aspect. The retainer comprises a recess surrounding the bore and at least one lip that projects from the periphery of the recess toward the bore to partially cover at least a portion of the recess. The at least one lip of the retainer may be a substantially continuous lip projecting from the outer periphery of the recess.

Also disclosed herein is a vibration absorbing device comprising a retainer comprising opposing first surface and second surfaces and a centrally located bore extending between the first and second surfaces and further comprising a recess. The vibration absorbing device also comprises a compression member configured to be held within the retainer, wherein a first surface of the compression member extends beyond the first surface of the vibration absorbing device.

In one form, the retainer comprises a centrally located recess formed at the first surface of the retainer and also comprises a lip that projects from the retainer toward the bore to partially cover the recess. Preferably, the recess substantially surrounds the bore of the retainer.

In one form, the compression member comprises a second surface substantially opposing the first surface of the compression member and a centrally located aperture that extends between the first and second surfaces of the compression member and that substantially aligns with the bore of the retainer and wherein the compression member comprises an outer wall from which at least one flange projects.

The compression member may be located within the recess of the retainer such that the flange of the compression member is held beneath the lip of the retainer.

In one form, at least two flanges are provided on opposing sides of the compression member. In another form, three or more flanges are provided and are spaced evenly around the outer wall of the compression member. Preferably, the at least one flange extends around the entire periphery of the compression member. Preferably, the recess is an annular recess and the compression member is in the shape of a ring and is dimensioned to fit within the annular recess

Preferably, the compression member comprises a plurality of recesses or apertures formed in the outer wall and/or an opposing inner wall of the compression member.

Preferably, a plurality of recesses and/or apertures are formed in the first and/or second wall of the compression member

Preferably, the device further comprises a shaft that extends from the second surface of the retainer and comprises a centrally located bore that extends along the length of the shaft and substantially aligns with the bore of the collar. Preferably, the bore of the shaft has a threaded surface. Alternatively, or additionally, the bore of the retainer has a threaded surface. In some forms, the surface of the bore of the shaft and/or retainer may be polyurethane.

Preferably, the compression member is made of polyurethane.

In a second aspect, the invention provides a power tool attachment comprising a vibration absorbing device according to the first aspect of the invention.

Preferably, the power tool attachment is a brush attachment.

In a third aspect, the invention provides a retainer for a vibration absorbing device according to the first aspect of the invention. The retainer comprises first and second surfaces and a centrally located bore extending between the first and second surfaces and further comprises a retainer.

The retainer may comprise a centrally located recess formed at the first surface of the retainer and may also comprise a lip that projects from the retainer toward the bore to partially cover the recess. Preferably, the recess substantially surrounds the central bore of the collar.

Also disclosed herein is a vibration absorbing device comprising a retainer having opposing first and second surfaces and a centrally located bore extending between the first and second surfaces, wherein a centrally located recess is formed in the first surface of the retainer and surrounds the bore, wherein a portion of the first surface of the retainer forms a lip that projects inwardly toward the bore to partially cover the recess; and wherein the device also comprises a compression member having an outer wall from which a flange projects, the compression member comprises a first surface and an opposing second surface and a centrally located aperture that extends between the first and second surfaces of the compression member and that substantially aligns with the bore of the retainer.

Any reference to prior art documents in this specification is not to be considered an admission that such prior art is widely known or forms part of the common general knowledge in the field. As used in this specification, the words "comprise", "comprises", "comprising", and similar words, are not to be interpreted in an exclusive or exhaustive sense, In other words, they are intended to mean "including, but not limited to".

Preferred forms of the invention will now be described by way of example only and with reference to the following drawings. It will be appreciated that the invention as claimed is not intended to be limited in any way by these examples.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a perspective view of a brush attachment according to the prior art:

Figure 2 is a perspective view of one form of vibration absorbing device according to the present invention;

Figure 3 is a cross-sectional side view of the vibration absorbing device of Figure 2;

Figure 4a is a side view of one form of device according to the invention ;

Figure 4b is a cross-sectional side view of the device taken along line A-A of Figure 4a;

Figure 5a is a side view of one form of compression member according to the invention ;

Figure 5b is a cross-sectional side view of the compression member taken along line A-A of Figure 5a;

Figure 6 is a perspective view of one form of compression member in the shape of a ring;

Figure 7a is a side view of one form of vibration absorbing device according to the invention ;

Figure 7b is a cross-sectional side view of the vibration absorbing device taken along line A-A of Figure 7a;

Figure 8a is a perspective view of another form of compression member according to the invention ;

Figure 8b is a side view of the compression member of Figure 8a ;

Figure 8c is a cross-sectional side view of the compression member taken along line A-A of Figure 8b;

Figure 9a is a perspective view of another form of compression member according to the invention ;

Figure 9b is a side view of the compression member of Figure 9a ;

Figure 9c is a cross-sectional side view of the compression member taken along line A-A of Figure 9b;

Figure 10a is a perspective view of another form of compression member according to the invention;

Figure 10b is a side view of the compression member of Figure 10a; Figure 10c is a cross-sectional side view of the compression member taken along line A-A of Figure 10b;

Figure 11a is a side view of a brush attachment to which is attached one form of vibration absorbing device according to the invention; and

Figure lib is a cross-sectional side view of the brush attachment taken along line A-

A of Figure 11a

Figure 12a is a side view of another form of device according to the invention; and Figure 12b is a cross-sectional side view of the device taken along line A-A of Figure

12a.

DETAILED DESCRIPTION

The invention relates to a power tool device that can be used as a vibration absorbing device and/or as an anti-lock device for attachment to a power tool or to a power tool attachment, such as a brush attachment. The power tool device comprises a retainer adapted to hold a compression member therein. In one form, the device is configured to reduce the vibrations transferred from a power tool attachment to the body of a power tool in use, so that the vibrations experienced by a user of the power tool are also reduced. Alternatively or additionally, the device is configured to reduce the likelihood that a power tool attachment will lock against a power tool and become difficult to detach.

The device of the invention will now be described as if the device is for use with a brush attachment, but it should be appreciated that the device may used with any suitable power tool attachment without departing from the scope of the invention, including but not limited to: a sanding head, an orbital cutting head, a buffing head, or any other head or attachment for a power tool that creates vibration during use,

As shown in Figure 1, a typical brush attachment 300 comprises a cup 310 that supports and partially surrounds a plurality of bristles 320 to form a brush. The cup 310 has a substantially convex outer surface with an attachment region 330 where the brush attachment is to be attached to a power tool, such as an angle grinder. The attachment region 330 is typically metal and often the entire cup 310 is metal. The attachment region 330 is typically a substantially flat region that is centrally located on the outer surace of the cup 310. A centrally located aperture is formed in the attachment region 330 of the cup. A nut 340 is attached to the attachment region 330 of the cup and is positioned so that the bore 350 of the nut aligns with the central aperture of the cup. The bore of the nut 340 is a threaded, centrally located bore 350 for engaging with the threaded spindle of a power tool, such as an angle grinder, to attach the brush attachment 300 to the angle grinder.

Figure 2 shows one form of power tool device 100 according to the invention that can be used with the power tool attachment 200. For example, the device 100 can be attached to a brush attachment, such as that shown in Figure 1, instead of the nut, or to any other power tool attachment.

The device comprises a retainer 120 and optionally comprises an attachment memberl30 that extends from the retainer. The device also comprises a compression member 140 that is adapted so that at least a portion of the compression member is held by the retainer 120 and at least a portion of the compression member extends beyond the retainer.

In one form, as shown in Figures 2 and 3, the power tool device comprises a retainer 120 and an attachment member in the form of a shaft 130 that is configured to attach the device to a power tool or to a power tool attachment.

In one form, as shown in Figures 4A and 4B, the retainer 120 comprises opposing first and second surfaces 121a, 121b. A bore 122 extends through the retainer. In one form, the bore is located substantially centrally on the first surface of the retainer. Typically, at least a portion of the surface of the bore 122 is threaded.

In one form, the retainer comprises a recess 123 and at laest one lip 124. The recess 123 is formed on the first surface of the retainer and substantially surrounds the bore 122. However, in other forms, the recess may only surround a majority of the bore. Alternatively, more than one recess may be provided around the bore, such as a pair of opposing recesses or a series of recesses located around the bore of the collar. In these forms, one side of the compression member is specially shaped to fit within the recess(es) so that the opposing side of the compression member remains substantially level.

In one form, a portion of the first surface 121a of the retainer projects inwardly toward the bore 122 and partially covers the recess 123 to form an inwardly projecting lip 124. The lip 124 at least partially surrounds the outer periphery of the recess 123, as seen in Figures 3 and 4b. In this form, the lip is substantially continuous around the outer edge of the recess,

In other forms, a plurality of inwardly facing projections are spaced around the outer periphery of the recess. For example, two or more lips may be spaced equidistant around the outer edge of the recess.

The at least one lip may project at the first surface of the retainer or between the first surface of the retainer and the bottom of the recess. For example, one or more walls 126 of the recess may comprise one or more projections that project inwardly toward the bore 122 to form a continuous lip 124 substantially surrounding the periphery of the recess 123 or to form two or more lips 124 spaced around the periphery of the recess and configured to hold at least a portion of the compression member within the retainer. Preferably, the two or more lips are equidistant from each other. Preferably, the retainer 120 has at least two substantially flat opposing gripping regions 125 by which a wrench can grip the retainer, as shown in Figures 4a, 7a, and 12a, The gripping regions 125 may be textured to provide a better grip on the retainer 120.

In one form, as shown best in Figure 2, the retainer is a substantially hexagonal shape, similar to that of a hex nut, so that any two opposing sides of the hex shape can act as gripping regions. In other forms, the retainer may be square, octagonal, or of any other suitable shape. Preferably, the retainer is a regular shape having flat sides of equal length and at least two opposing sides.

The power tool device shown in Figures 2 to 7b further comprises a shaft 130 having opposing first and second ends 131a, 131b. The shaft 140 is attached to or integral with the retainer 120 such that the shaft projects from the second surface 121b of the retainer. Typically, the first end 131a of the shaft projects from the retainer to form a free end.

The shaft comprises a centrally located bore 132 that extends along the length of the shaft and substantially aligns with the bore 122 of the retainer to provide the power tool device with a spindle receiving bore. In one form, the shaft is cylindrical and the bore 132 of the shaft has a threaded surface, although in another form, as shown in Figure 7b, the bore 132 is not threaded. In one form, the shaft has a threaded outer surface.

The power tool device 100 also comprises a compression member 140 having first and second opposing surfaces 141a, 141b, and a bore 142 extending between the first and second surfaces. Typically, the bore 142 is centrally located on the first surface of the compression member. The compression member also comprises an inner wall 143a and an outer wall 143b. The inner wall 143a defines the bore 142 of the compression member and the outer wall defines the peripheral edge of the compression member.

One form of compression member is shown in Figures 5a and 5b. The compression member 140 and retainer are configured so that the first surface 141a of the compression member projects beyond the first surface 121a of the retainer. For example, the power tool device is configured so that, in use, the first surface of the compression member 141a abuts a surface of the power tool to which the device of the invention is attached. The first surface of the retainer does not contact the power tool.

The compression member may be detachable or it may be permanently fixed in position.

In one form, the compression member is positioned within the recess of the retainer so that the bore of the compression member substantially aligns with the bore 122 of the retainer.

In one form, at least one flange 144 extends from the outer wall 143b of the compression member. The at least one flange is adapted to sit within the recess 123 of the retainer and beneath the at least one lip 124 so that the lip(s) act(s) to hold a portion of the compression member 140 within the recess, as shown in Figures 7a and 7b. In this manner, the recess 123 and lip 124 form a housing that houses a portion of the compression member 140. In a preferred form, the at least one flange extends around all or most of the outer wall of the compression member. For example, where the compression member forms a ring shape, the flange may extend around all or most of the circumference of the outer wall of the ring. In another form, at least two flanges extend from the outer wall of the compression member, the flanges being located on substantially opposing sides of the outer wall. In yet other forms, three or more flanges may be spaced from each other and extend from the outer wall of the compression member. Preferably, the flanges are equidistant from each other. In a preferred form, the at least one flange projects from the outer wall of the compression member at or near the second surface of the compression member. In another form, the at least one flange projects from a region of the outer wall between the first and second surfaces of the compression member, preferably at a region that is located substantially centrally between the first and second surfaces of the compression member.

The recess 123 and the compression member 140 may be of any suitable complementary shape and dimensions such that the compression member can substantially fit within the recess. In a preferred form, as shown in Figures 2, 3, and 6, the recess 123 of the retainer is a circular recess (the bore of the retainer being centrally located within the recess) and the compression member 140 has a circular outer wall 143b and centrally located bore 142 to form a ring shape. In other forms, the recess and compression member may be substantially oval. In yet other forms, the recess and compression member may be a quadrilateral shape or any other suitable regular or irregular shape. Therefore, the recess may comprise one substantially continuous wall or the recess may comprise a plurality of walls. The bore of the compression member typically aligns with the bore of the retainer.

To help the compression member to fit well within the recess of the retainer, the second surface of the compression member may comprise a chamfered outer edge 145.

In another form, the compression member is adapted to be adhered or otherwise fixed to the retainer. In this form, the retainer comprises a first surface, which may be substantially planar or it may be the surface of a three dimensional body. Typically, the first surface of the retainer is substantially flat, but in some forms the first surface may be textured or ribbed and/or the second surface of the compression member may be textured or ribbed to help the compression member adhere to the retainer or to help reduce slipping between the compression member and retainer.

In other forms, the retainer may be adapted to interlock with the compression member. For example, a retainer comprising one or more clips may be used to hold onto one or more flanges of the compression member. Alternatively, the retainer may comprise one or more clips or claws that engage with one or more recesses or openings formed in the outer periphery of the compression member. In all forms, the compression member is attached to the power tool device and the compression member and retainer are configured so that the first surface of the compression member projects beyond the first surface of the retainer.

In one form, the compression member may comprise a plurality of apertures and/or recesses formed in the body of the compression member to enhance its ability to flex and compress, so that the compression member more effectively absorbs vibrations. The recesses may be formed in the first and/or second surfaces of the compression member or in the inner and/or outer walls of the compression member. For example, Figures 8a to 8c show a plurality of recesses 146 in the form of channels that extend around the circumference of the outer wall 143b of the compression member. In this embodiment, the recesses form a ribbed outer wall. Similarly, the apertures may extend between the first and second surfaces or between the inner and outer walls of the compression member. For example, Figures 9a to 9c show a plurality of apertures 147 that extend between the first and second surfaces 141, 141b of the compression member. The apertures may extend the complete distance between the first and second surfaces of the compression member or the apertures may extend only partially between the first and second surfaces to form recesses in the compression member. In yet another form, one or more apertures may be provided within the body of the compression member so that the aperture(s) do not comprise an exposed opening. In this form, the compression member comprises one or more hollow regions. In another form, as shown in Figures 10 to 10c, the compression member may comprise a plurality of apertures 147 that extend between the inner and outer walls 143a, 143b.

In another form, multiple compression members may be located on and attached to the first surface of the retainer, the compression members being spaced equidistant from each other around the bore of the retainer. For example, a pair of compression members may be used, one on either side of the retainer bore. Alternatively, three or more compression members may be spaced around the retainer bore. The compressino members may be attached to the retainer using any suitable method of attachment so that the first surface of each compression member projects beyond the first surface of the retainer. For example, the compression members may be adhered to the retainer.

The compression member(s) may be made from any suitable material that is sufficiently resilient to withstand the compression forces exerted by a moving power tool attachment, but is also sufficiently flexible to absorb at least some of or part of those compression forces. One suitable material for the compression member is polyurethane. Other suitable materials include PVC, LDPE, Viton, and thermoplastic elastomers.

In one form, as shown in Figures 11a and lib, the power tool device is attached directly to a power tool attachment 200, such as a brush attachment.

The brush attachment 200 comprises a cup 210 that supports and partially surrounds a plurality of bristles (not shown) to form a brush. The cup 210 has a first surface 211a in the form of a convex outer surface with a substantially flat central attachment region 212, A central aperture 213 is formed in the central region. A second surface 211b of the cup is in the form of a concave inner surface from which the bristles of the brush extend. The central aperture 213 is adapted to receive the shaft 130 of the power tool device 100 therein. In particular, the shaft 130 of the power tool device is held within the central aperture 213 of the brush attachment so that the second surface 121b of the retainer 120 abuts the attachment region 212 of the cup.

In one form, the central aperture 213 of the cup is a bore having a threaded surface and the outer surface of the shaft 130 is also threaded so that the device of the invention can be screwed onto the cup of the brush attachment. A tight fit can be obtained by using a wrench against gripping regions of the retainer to tighten the device against the brush attachment. In another form, the shaft of the device is adapted to be pushed into the central aperture to interlock with the brush attachment and form a snug fit. An adhesive may then used to hold the device in place. In another form, the shaft of the device extends through the bore of the brush attachment cup and the device is fixedly attached to the cup by a nut, welds, or by any other suitable form of attachment, as shown in Figures 7a and 7b. In yet another form, the brush attachment cup and power tool device of the invention may be integrally formed as one part.

The spindle receiving bore 150 of the power tool device 100 is configured to receive the output spindle of a power tool (not shown). Therefore, to attach the brush attachment 200 to a power tool, such as an angle grinder, the spindle of the angle grinder is screwed into the bore 150 of the power tool device until the first surface 121a of the compression member 140 abuts the body of the angle grinder.

In another form of the invention, the device comprises only a retainer 120, as described above and as shown in Figures 12a and 12b, In other words, the device does not comprise an attachment memberm such as a shaft, extending from the retainer. In this form, the retainer of the device may be integral with, welded, adhered, or may be otherwise removably or fixedly attached to the first surface of the central region of the brush attachment cup. The retainer is positioned on the cup so that the bore 150 of the retainer substantially aligns with the central aperture of the cup. The surface of the bore of the retainer may be threaded, or the central aperture of the cup may define the opening of a threaded bore provided in the cup, or both the bore of the retainer and the bore of the cup may be threaded.

The brush attachment with attached power tool device of the invention may then be screwed onto the output spindle of a power tool, such as an angle grinder, by inserting the free end of the spindle into the threaded bore of the retainer and/or cup until the spindle and bore mesh together. The brush attachment may be screwed to the spindle until the first surface of the compression member of the power tool device contacts the body of the angle grinder, A tight fit can be obtained by using a wrench against gripping regions of the retainer to tighten the power tool device (and attached cup) against the body of the angle grinder.

Alternatively, the power tool device of the invention can be threaded onto the output spindle of a power tool before the power tool attachment is also threaded onto the spindle. To enable the power tool device to be attached to the output spindle in this way, the bore 150 of the device (which comprises the bore of the retainer and will also comprise the bore of the shaft if the device comprises a shaft) has a threaded surface for meshing with the threaded output spindle. In this arrangement, the power tool device is positioned between the power tool attachment and body of a power tool. In this configuration, the power tool device of the invention may absorb at least some of the vibrations from the power tool attachment so that the vibrations transferred to the body of the power tool are reduced. In this configuration, the power tool device may also reduce the likelihood that the power tool attachment will lock against the power tool and be difficult to remove. In other words, the power tool device of the invention may provide a vibration absorbing system and/or an anti- lock/a nti -grab system.

In another form, the power tool device 100 is configured so that the second surface of the retainer is adapted to hold a portion of a second compression member. For example, the second surface of the retainer may comprise a second recess into which a second compression member is fitted, as described above, to better absorb the vibrations of the power tool attachment, The second recess may be centrally located on the second surface of the retainer or it may be concentrically located about the shaft of the device, where the device comprises a shaft projecting from the second surface of the retainer. Alternatively, the second compression member may be attached to the second surface of the retainer in any suitable arrangement in which the first surface of the compression member projects beyond the second surface of the retainer. For example, the second compression member may be adhered to the second surface of the retainer. In use, the first compression member projects from the first surface of the retainer and contacts the body of a power tool, The second compression member projects from the second surface of the retainer and contacts the power tool attachment that is attached to the power tool .

In all embodiments, when the power tool is in use, the compression member may provide a resilient cushion between the power tool attachment and the body of the power tool. As the power tool attachment vibrates, at least some of the vibrations may be absorbed by the compression member so that the vibrations transferred from the power tool to a user are reduced . As the power tool attachment vibrates, the compression member may also reduce the risk that the power tool attachment will lock against the power tool and become difficult to detach. Furthermore, in some forms, if the compression member fails, such as by splitting, or otherwise deteriorates and needs to be replaced, the compression member can be levered out of its recess or otherwise removed from the retainer, A replacement compression member can then be placed in the recess and held in place by the at least one lip of the retainer or may be otherwise attached to the retainer.

Advantages

The power tool device of the invention provides the advantage that, in some forms, the device is mounted to a power tool attachment so that the power tool attachment can be attached to an output spindle of a power tool without needing to provide a separate compression device between the power tool attachment head and power tool body.

In some forms, the device of the invention also allows the compression member to be replaced without needing to replace the entire device. This is particularly important where the device is integrally formed with or permanently attached to a power tool attachment such as by welding, adhesive, or by any other form of permanent attachment.

A further advantage of the device of the invention is that it may provide anti-grab or anti-lock benefits that allow a power tool attachment head to be removed from a power tool by hand, without needing to use a wrench or other tool to loosen the attachment head. This is because the compression washer forms a soft joint against which the metal of a power tool body presses when the attachment head is attached to a power tool. The soft joint avoids a metal to metal connection, which disadvantageously causes the metal contact region of the attachment head to lock hard against the metal contact region of the power tool body, making it difficult to detach the power tool attachment head from a power tool.

The power tool device of the invention also prevents overtightening of the attachment head to a power tool. Therefore, the attachment head may be loosened and removed by hand, without needing a tool, such as a wrench or the like.

Although the invention has been described by way of example, it should be appreciated that variations and modifications may be made without departing from the scope of the invention as defined in the claims. Furthermore, where known equivalents exist to specific features, such equivalents are incorporated as if specifically referred in this specification.