WO2003099496A2

WO2003099496A2 - Rotary foam sanding tool and method for manufacture

Info

Publication number: WO2003099496A2
Application number: PCT/US2003/016709
Authority: WO
Inventors: Michael M. Homma
Original assignee: Homma Michael M
Priority date: 2002-05-28
Filing date: 2003-05-27
Publication date: 2003-12-04
Also published as: WO2003099496A3; AU2003234662A8; AU2003234662A1

Abstract

A rotary foam sanding tool for use with a powered rotary hand tool has a shaft (110) connected to a hub or mandrel (115), an abrasive surface contacting layer (135), a compressive foam layer (130) intermediate the abrasive surface contacting layer and the mandrel. The abrasive surface contacting layer in on the exterior of the tool and is comprised of an abrasive substance. The compressive layer is composed of tubular polyethylene foam that has been treated with a fluorination process that allows the glue to adhere to the surface of the polyethylene foam. The rotary foam sanding tool may also include a mandrel contacting layer (425). The mandrel contacting layer is intermediate the mandrel (415) and the compressive foam layer (430), and the compressive foam layer is intermediate the mandrel contacting layer and the abrasive surface (435).

Description

Rotary Foam Sanding Tool And Method for Manufacture

Inventor: Michael M. Homma

Cross-Reference To Related Application [0001] This application claims the benefit of U.S. Provisional Patent Application

No. 60/319,277 filed on May 28, 2002, which is incorporated herein by reference.

Background of Invention

1. Field of Invention

[0002] The present invention relates generally to rotary sanding tools and more specifically to a tool that can be used in the fingernail industry, or hobby and crafts tool industry.

2. Description of the Related Art

[0003] In the artificial fingernail and hobby and crafts tool industry, the need exists for a tool that can be used to shape and prepare an object in preparation for accepting a suitable finish coating without using manual sanding steps or resorting to tools that require a great degree of manual dexterity on the part of the tool user in order to obtain an acceptable finish. Prior Art inventions met one or more of the above requirements but not all. For example, the prior art often requires numerous manual steps causing wrist strain due to repetitive movement required by a manual sanding tool. Although mechanical tools can be used to speed up the process and reduce wrist fatigue, current tools are difficult to manipulate on fine levels of detail and can potentially damage the material or person being worked upon. Because of their unforgiving nature, the tool operator must slow down to insure that the object being worked upon is not damaged or injured. Therefore, both the manual and mechanically automated prior art added additional time to the process of sanding an object in preparation for finishing.

[0004] Previous equipment included manual files, which slowed down the process of finishing an object, diamond and carbide bits, which were quick for cutting and shaping but required significant manual dexterity in order to properly shape an object without damaging the object that is being shaped.

[0005] Cylindrically or spirally wound sanding bands, as shown in Figure 2 are made of the same material as larger commercial belt sanders, thus they allow quick shaping of an object but have the same drawbacks as previous rotary sanding tools, specifically, they require a high level of manual dexterity to properly shape an object without damaging the object being shaped. The construction materials of a spirally wound sanding band is very rigid. Any slip while using such a tool would cause gouges or cuts in the material being worked upon. The ability to not damage the object being shaped is extremely important in the artificial fingernail application industry because the damage that would be inflicted upon the wearer of the artificial fingernail and if the user of the tool slipped and touched the cuticle area surrounding the fingernail, can be significant and very painful. [0006] Foam sanding blocks, as shown in Figure 1, have been used for quite some time in the hobby and fingernail industries, which allow the shaping, and sanding of odd shaped materials by hand. These blocks are typically made of polyurethane foam and manufactured as described in U.S. Patent No. 5,849,051 assigned to the 3M Corporation. Polyurethane foam is used because the open cell nature of the material allows grit to be deposited in the recesses of the foam creating additional abrasive surface area for greater performance and longer wear. Polyurethane also accepts standard flexible glues, which are common for sanding foams. While the block polyurethane sanding foams make it easier to reach the contours of small curved objects, they still required much manual effort on the part of the tool user to accomplish the goal of preparing the objects surface for finish application.

[0007] A prior art rotary buffing tool, with four layers as described in U.S. Patent

No. 6,162,117 and as shown in FIG. 3, has limited use because the materials and method of construction limit the minimum diameter of the device. Tools produced according to the '117 patent result in a tool having a diameter greater than "1/4 of an inch, in some cases as much as three times greater. The tripling of the diameter is particularly problematic because it spins the outer diameter of the tool at three times the speed of a normal 1/4" sanding band, causing the tool to delaminate and fling the foam and abrasive material off of the mandrel engaging section destroying the tool and endangering the tool operator and anyone else nearby. The stated maximum RPM operation of the tool according to the '117 patent is 600 RPM, which restricts this tool from being used by many of the commonly used rotary powered hand tools because the lowest speeds achievable are greater than 600 RPMs. The typical speed range of such tools, for example the UPower UP200, is from 6000 to 30,000 RPM. Furthermore, construction of this tool uses spiral winding techniques similar to traditional sanding bands where the mandrel engaging layer is a polyethylene tube to which a layer of two sided polyethylene foam tape is applied at a 45 degree angle to the tube and a layer of sandpaper or abrasive coated material is applied in the opposite direction polyethylene foam tape perpendicular to the polyethylene foam tape to add additional strength to its construction. This method of construction is very complex and requires sophisticated machinery or a very manually labor intensive process to manufacture this device. This complex construction also raises the manufacturing cost of this device. [0008] Thus, there is a need for a low cost, easy to manufacture sanding tool that can be used with conventional power tools to, sand, buff and shape fingernails, artificial or real, and other objects.

Summary of Invention [0009] Accordingly, the present invention has several advantages. First, it allows a simpler construction using only three major components. In the preferred embodiment, this simple construction is a fluorine treated polyethylene foam tube, flexible glue, and an abrasive material. The manufacturing technique is similar to those currently employed in the making of other commercial sanding foams with the exception of the additional fluorine treating step used to make the adhesive stick to the polyethylene foam, and the substitution of polyethylene foam for polyurethane foam. The additional fluorine treating step is unique for the construction of a polyethylene abrasive foamed products and has not been employed on a polyethylene foam tube. In contrast to the present invention, the prior art applied sandpaper to the surface rather than applying the abrasive directly to the polyethylene foam. The cost of the construction materials and simple manufacturing process allow this invention to be produced at an extremely low cost.

[0010] Second, the use of compressive foam beneath the abrasive allows the user of the tool to work on objects without the negative effect of cutting or gouging the object being worked upon. A slip of the wrist no longer means a gouge in the working surface that needs to be repaired or in the case of an artificial fingernail, a cut on the finger of the wearer of the artificial nail. The tool having foam with abrasive directly thereon allows the user to sand or shape the object while the tool is very delicate to the object being sanded or shaped. [0011] Third, the present invention can be constructed so that its outer diameter is best suited for use with existing, conventional, rotary sanding tools. The use of the minimum thickness of foam and reducing the number of total layers, keeps the diameter of the tool within the normal operating limits of most rotary sanding tools. The preferred outer diameter of the invention is 3/8", which is slightly larger than the sanding band prior art shown in Figure 2. [0012] Fourth, the present invention uses environmentally friendly materials such as low volatile organic hydrocarbon (NOC) adhesives and polyethylene foam create less pollution during manufacturing and pose less impact on the environment once the material is discarded after its use.

[0013] Fifth, the present invention provides a lower operating temperature. The tool's compressible foam deforms slightly when pressed against an object being sanded or shaped, which causes the sanding surface to flatten slightly as the tool is being used. The flattened portion of the tool allows more cutting surface area to be exposed to the object that is being shaped or sanded. This additional cutting surface area allows the tool to be run at a lower RPM, while achieving the same sanding effect. The lower RPM decreases the rise in surface temperature caused by the friction of the tool which would normally occur at a higher RPM. The lowering of the sanding surface temperature means less heat damage to delicate objects while being shaped or sanded, and in the case of an artificial fingernail wearer, greater comfort during the process of getting a set of artificial nails refmished. [0014] The present invention is a foam sanding tool for use with a powered hand tool. The sanding tool comprises a shaft connected to a hub or mandrel, a surface contacting layer, and a compressive foam layer intermediate the surface contacting layer and the mandrel. The surface contacting layer is on the exterior of the tool and is comprised of an abrasive substance. Preferably the compressive foam layer is composed of tubular polyethylene foam that has been which has been treated with a fluorination process that allows the glue to adhere to the surface of the polyethylene foam. Preferably the compressive foam layer is thinner than the mandrel diameter to minimize the total diameter of the tool to allow the tool to operate safely at the high RPM encountered using normal rotary tools such as the UPower model number UP200 or Kupa model number 2000. It should be understood, that the surface contacting layer is an abrasive material directly attached to the exterior surface of the compressive foam layer. [0015] The present invention also includes a second embodiment of the foam sanding tool. The second embodiment of the present invention includes a rotary foam sanding tool for use with a rotary powered hand tool. The second embodiment of the rotary sanding tool comprises a shaft connected to a mandrel, a mandrel contacting layer, an abrasive surface contacting layer, and a compressive foam layer intermediate the mandrel contacting layer and an abrasive surface contacting layer. The mandrel contacting layer is intermediate the mandrel and the compressive foam layer. [0016] One objective of this invention is to provide a rotary foam sanding tool that allows the user to more quickly shape and polish small curved surfaces with less stress on the wrist of the user than previous manual or automated methods.

[0017] Still another objective of this invention is to provide an extremely inexpensive tool that allows the user to dispose of the tool after each use. In the fingernail application, this is also be done for health and safety reasons. In the hobby craft application this would be done for convenience.

[0018] Still another objective of this invention is to provide comfort to the wearer of an artificial fingernail during the entire nail shaping and polishing process by reducing the heat produced and time involved to apply or repair an artificial fingernail.

[0019] Further objects and advantages will become apparent from consideration of the drawings and ensuing description.

Brief Description of The Drawings [0020] FIG. 1 is a perspective view of a prior art foam sanding block.

[0021] FIG. 2. is a perspective view of a sanding band of the prior art.

[0022] FIG. 3 is an exploded perspective view of a nail buffing tool of the prior art.

[0023] FIG. 4 is a perspective view of a first embodiment of the present invention.

[0024] FIG. 5 is an exploded perspective view of the first embodiment of the present invention.

[0025] FIG. 6 is an exploded perspective view of a second embodiment of the present invention.

Detailed Description Of The Invention [0026] Referring now to Figures 4 and 5, the first and preferred embodiment of the present invention will be described. Figure 4 shows a system 100 including the tool 103 attached on a conventional drill 101. Fig 5 shows an exploded view of the first embodiment of the invention. This is the preferred embodiment of the invention and it comprises a drill portion 301, and a tool portion 303.

[0027] The drill portion 301 features a shaft 310 which is connected to a hub or mandrel 315.

[0028] The tool portion 303 comprises a compressive layer 330, an adhesion promotion surface treatment coating 325 and an abrasive surface contacting layer 335. The abrasive surface contacting layer 335 is connected to the surface treatment coating layer 325 by a flexible adhesive as outlined in 3M patent number 5,849,051 or other flexible PNC adhesives commonly used in the manufacturing of flexible sanding sponges such as HB Fuller N3869RB. The adhesion promotion surface treatment coating 325 is attached upon the compressive foam layer 330. The preferred adhesion promotion surface treatment layer 325 is applied to the compressive foam layer 330 by a proprietary process available from the Fluoroseal Corporation Houston, Texas. Other suitable surface treatments include, but not limited to, corona treating, flame treating, and other adhesion enhancement methods that raise the surface energy to enhance the adhesion properties of the polyethylene foam to accept standard flexible adhesives currently used in the foam abrasive industry. The outer diameter of the tool 303 is preferably 0" to 1/2" with the outer diameter more preferably being 1/4" to 3/8". The length of the tool 303 is preferably about from 1/2" to 1" with the length preferably being closer tol/2". As can be seen the tool 303 preferably has a tube shape. The tube shape has an inner diameter that is adapted for a friction fit upon the mandrel 315.

[0029] The compressive foam layer 330 is preferably composed of a compressible foam substance referred to in the trade as being a foam object such as, but not limited to, automotive nitrile, closed cell rubber, polyurethane foam, polyethylene foam or polypropylene foam. The thickness of the compressible foam layer 330 is made as thin as possible while still maintaining the cushioning function of the foam to keep from adding more than necessary to the diameter of the tool 303. The thickness of the compressive foam layer 330 may be 1/16" to 3/8" in thickness with the thickness preferably being 3/16" compressing to less than 1/8" thickness once placed snugly on the mandrel 315. The inner diameter of the compressible foam layer 330 is slightly smaller that the outer diameter of the mandrel 315, for example, one 1/16⁴¹ of an inch. Since the compressive foam layer 330 has elastic properties, it can be stretched to fit over the mandrel 315 for secure friction fit. [0030] The preferred surface treated coating layer 325 is formed by a proprietary process of the Fluoroseal Corporation of Houston, Texas and covers the outer layer of the compressible foam layer 330.

[0031] The abrasive surface contacting layer 335 may be composed of an abrasive material suitable for sanding sponges or sandpaper. The abrasives that may be used contain, but are not limited to silicon carbide, diamonds, synthetic diamonds, garnet, aluminum oxide, and alumina-zirconia. This abrasive surface contacting layer 335 is directly attached to the compressible foam layer 330 with a suitable flexible adhesive and the surface treated coating layer 325 as described above. The abrasive surface contacting layer 335 is advantageous over the prior art in that no backing such as paper or other material is required.

[0032] Fig 6 shows an exploded view of a second embodiment of the present invention. This second embodiment of the present invention comprises a drill portion 401, and a tool portion 403. The drill portion 401 features a shaft 410 which is connected to a hub or mandrel 415. The tool portion 403 has a hub or mandrel engaging layer 425, a compressive foam layer 430 and an abrasive layer 435. The mandrel engaging layer 425 is connected to the compressive foam layer 430. The compressive foam layer 430 is connected to the abrasive layer 435 by a flexible adhesive as outlined in 3M patent number 5,849,051 or other flexible PVC adhesives commonly used in the manufacturing of flexible sanding sponges such as HB Fuller N3869RB. The external diameter of the tool 403 is 1/4" to 1/2" with the external diameter more preferably being 1/4" to 3/8". The length of the tool 403 is from 1/2 " to 5/8" with the length preferably being 1/2".

[0033] The mandrel engaging layer 425 is composed of, but not limited to, plastic, fabric, or metal. The preferred material being polyethylene plastic. The mandrel engaging layer 425 is provided to provide better attachment of the compressive foam layer 430 to the mandrel 315.

[0034] The compressive layer 430 may be composed of a compressible foam substance referred to in the trade as being a foam object, including, but not limited to, automotive nitrile, closed cell rubber, polyurethane foam, polyethylene foam and polypropylene foam. The thickness of the compressible foam layer is made as thin as possible while still maintaining the cushioning function of the foam to keep from adding more than necessary to the diameter of the tool. The thickness of the foam layer may be 1/16" to 3/8" in thickness with the thickness preferably being 3/16" compressing to less than 1/8" thickness once placed snugly on the mandrel 415.

[0035] The abrasive surface contacting layer 435 may be composed of an abrasive material suitable for sanding sponges or sandpaper. The abrasives that may be used contain, but are not limited to silicon carbide, diamonds, synthetic diamonds, garnet, aluminum oxide, and alumina-zirconia. This abrasive surface contacting layer 435 is connected directly to the compressible foam layer with a suitable flexible adhesive as outlined in U.S. Patent No. 5,849,051 assigned to the 3M Corporation.

[0036] The present invention also includes a method for manufacturing the tool 303 of the present invention. The process begins with a tube of compressible foam. The tube of compressible foam has an inner and outer diameter as has been noted above. However, the tube preferably has a length of several feet. The tube of compressible foam then has its exterior surface treated and coated with an adhesion promotion surface treatment. As noted above, the preferred embodiment is a proprietary process available from the Fluoroseal Corporation of Houston, Texas. After the tube has been treated with the adhesion promotion surface treatment, an adliesive is applied to the exterior surface of the tube. After the adhesive has been applied, an abrasive grit is placed over the exterior surface of the tube. This can be done by spraying directly or indirectly the abrasive grit over the exterior of the tube for an even coating of abrasive material. The portions of the abrasive grit that do not adhere to the tube are removed, and finally the tube is cut into sections of a desired length as has been described above.

[0037] The above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. The scope of the invention is to be limited by only the following claims. From the above discussion, many variations will be apparent to one skilled in the relevant art that would yet to be encompassed by the spirit and scope of the invention.

Claims

WHAT IS CLAIMED IS:

1. A sanding device for use with a powered hand tool, the sanding device comprising: a compressive layer; an adhesion promoting layer attached on an exterior of the compressive layer; and an abrasive attached to the exterior of the compressive layer by the adhesion promoting layer and an adhesive.

2. The sanding device of claim 1, wherein: the powered hand tool comprises a shaft and a mandrel, the shaft adapted for connection to a drill, and the mandrel connected to the shaft; and the compressive layer has an inner diameter adapted to receive the mandrel and the compressive layer has a thickness in the range of 1/16" to 3/16" after the compressive layer is inserted on mandrel.

3. The device according to claim 1, wherein the abrasive is an abrasive grit and is one from the group including silicon carbide, diamonds, synthetic diamonds, garnet, aluminum oxide, and alumina-zirconia.

4. The device according to claim 1, which includes a compressive layer intermediate the mandrel and the surface treated adhesion promoting layer.

5. The device according to claim 1, wherein the abrasive layer is secured directly to the surface treated adhesion promoting layer.

6. The device according to claim 1, wherein the adhesion promoting layer is comprised of an adhesion promoting surface treatment.

7. The device according to claim 6, wherein the adhesion promoting surface treatment is a treatment from the group of fluorine surface treating, corona surface treating, and flame treating.

8. The device according to claim 1, wherein the compressive layer is comprised of a foam substance.

9. The device according to claim 8, wherein the foamed substance is one from the group of foam rubber, sponge, automotive nitrile, closed cell rubber, polyethylene foam and polyurethane foam.

10. The device according to claim 1, wherein the compressive layer has a cylindrical shape.

11. The device according to claim 1, wherein the compressive layer has a tube shape.

12. A rotary foam sanding tool for use with a powered rotary hand tool, the rotary foam sanding tool comprising a shaft, the shaft for connection to the powered rotary hand tool, a mandrel, the mandrel connected to the shaft, a mandrel contacting layer, a compressive foam layer, and an abrasive layer, the mandrel contacting layer positioned intermediate the mandrel and the compressive foam layer, the compressive foam layer positioned intermediate the mandrel and the abrasive layer, the abrasive layer being on the exterior of the rotary foam sanding tool, the abrasive layer comprising an abrasive grit, the compressive foam layer having a thickness in the range of 1/16" to 3/16" after the compressive foam layer is inserted on the mandrel.

13. The tool according to claim 12, wherein the abrasive grit is one from the group of silicon carbide, diamonds, synthetic diamonds, garnet, aluminum oxide, and alumina- zirconia.

14. The tool according to claim 12, wherein the compressive foam layer is positioned intermediate the mandrel engaging layer and the abrasive layer.

15. The tool according to claim 12, wherein the mandrel engaging layer is comprised of plastic, fabric, or metal.

16. The tool according to claiml2, wherein the compressive foam layer is comprised of a foamed substance.

17. The tool according to claim 14, wherein the foamed substance is one from the group of foam rubber, sponge, automotive nitrile, closed cell rubber, polyurethane foam, polyethylene foam and polypropylene foam.

18. A method for manufacturing a sanding tool, the method comprising the steps of: receiving a tube of compressible foam; applying an adhesion promotion surface treatment to an exterior surface of the tube of compressible foam; applying an adhesive on the exterior surface of the tube of compressible foam; placing an abrasive grit on the adhesive and the exterior surface of the tube of compressible foam; and cutting the tube of compressible foam into sections.

19. The method of claim 18 wherein the tube of compressible foam is one from the group of foam rubber, sponge, automotive nitrile, closed cell rubber, polyurethane foam, polyethylene foam and polypropylene foam.

20. The method of claim 18 wherein the abrasive grit is one from the group of silicon carbide, diamonds, synthetic diamonds, garnet, aluminum oxide, and alumina- zirconia.

21. The method of claim 18 wherein the adhesion promoting surface treatment is a treatment from the group of fluorine surface treating, corona surface treating, and flame treating.

22. The method of claim 18 wherein the cutting step is performed by cutting the tube along a plane orthogonal to the longitudinal axis of the tube.