The present invention relates to apparatus and methods for removing scratches from smooth surfaces such as glass. More specifically, the present invention relates to a polishing wheel and methods for manufacture and for use in removing the scratches.
Rotary tools are used to grind and polish glass to remove scratches and other damage from the surface of the glass. After processing the glass, such as windshields, it is desirable to leave the glass so the scratch or other damage is less visible and/or less likely to affect viewing through the glass. U.S. Pat. Nos. 4,709,513 and 4,622,780 show various tools for use in polishing glass.
Further improvements are desired for the rotary tools and methods used to polish glass.
The present invention relates to a polishing wheel including a body defining a central longitudinal axis and a central passage coaxial with the longitudinal axis. The body is mountable to a rotating polishing device. The body of the polishing wheel has a lower polishing surface including a planar portion. The lower polishing surface includes a plurality of main flutes extending from the central passage to an outer edge of the lower polishing surface. Further flutes extend from the outer edge of the lower polishing surface and terminate without communicating with the central passage or the main flutes.
In one embodiment, the main flutes have a different depth between the central passage and the outer edge. As the lower portion of the body of the polishing is worn away during use, the different depth portion allows for the main flutes to be reformed or recut so as to again be in fluid communication from the outer edge to the central passage if a portion of the main flute becomes worn away to a zero depth or an otherwise insufficient depth. In one preferred embodiment, the different depth portion is a varying depth portion located adjacent to the outer edge.
In one preferred method in accordance with the present invention, a polishing wheel is formed by providing a generally cylindrical disk of polishing material. The disk is formed, such as being cut with a tool, to include a plurality of main flutes located on a lower surface of the disk. The main flutes extend from a central passage to an outer edge. The main flutes preferably include a varying depth portion, adjacent to the outer edge. In one preferred method, the tool for cutting the main flutes is a circular saw. Preferably, secondary flutes separate from the main flutes are cut with the same circular saw. One preferred method uses an indexing machine to equally space the main flutes and the secondary flutes around a central axis of the disk during formation.
Referring to
Polishing wheel 10 includes a body 12 defining a central longitudinal axis 14. During use, body 12 is rotated about longitudinal axis 14. Polishing wheel 10 is designed for use with a center slurry feed tool like that described in the above noted patents.
Body 12 includes a central passage 16 which is coaxial with longitudinal axis 14. Central passage 16 is in fluid communication with the slurry source provided by the rotating tool as described in the above noted patents.
Body 12 further includes a lower portion or layer 18, and an upper portion or layer 20. Lower portion 18 defines a lower polishing surface 26. Upper portion 20 is located on an opposite side of lower portion 18 from polishing surface 26. An upper surface 28 is defined by upper portion 20 and faces in an opposite direction to polishing surface 26. Body 12 further defines a side surface extending between polishing surface 26 and upper surface 28. Polishing surface 26 extends from an inner edge 36 adjacent to central passage 16 to an outer edge 38.
Lower portion 18 includes main flutes 40 extending from central passage 16 at inner edge 36 to outer edge 38. In the preferred embodiment, main flutes 40 extend radially. In one preferred embodiment, main flutes 40 include reduced profile exit passages 42 for providing control of slurry outflow. Generally, a main portion 41 of main flutes 40 extends completely through lower portion 18. Exit passages 42 are shown in the illustrated embodiment as small v-grooves formed in lower portion 18. Main flutes 40 are arranged radially relative to longitudinal axis 14. Main flutes 40 are further arranged to be equally spaced from each other.
Secondary flutes 44 are also provided in lower portion 18. Secondary flutes 44 extend from outer edge 38 toward central passage 16. However, secondary flutes 44 terminate before communicating with central passage 16 or main flutes 40. In the illustrated embodiment, secondary flutes 44 extend all the way through lower portion 18. Secondary flutes 44 are radially arranged, and are equally spaced about polishing surface 26.
Central passage 16 includes a T-nut 46 which permits mounting of polishing wheel 10 to the rotating tool. Preferably, an inner surface of T-nut 46 is threaded. Spikes or other projections on T-nut 46 can be added to assist with holding T-nut 46 in position.
Preferably, body 12 is made from a moldable material. In the preferred embodiment, lower portion 18 and upper portion 20 are made from a common material, such as a moldable elastomeric material. Lower portion 18 is further provided with an impregnated material to facilitate polishing. Preferably, the impregnated material is a particulate. In one preferred embodiment, the particulate material is cerium oxide.
Upper portion 20 is not designed to polish. Therefore, no impregnated material for polishing is used in upper portion 20 in the preferred embodiment.
Preferably, lower and upper portions 18, 20 are molded together such that the layers are heat fused together. One preferred elastomeric material is expanded urethane. LP66 designation by Universal Photonics of Hicksville, N.Y. is one material for layer 18 that can be used. LP66 material includes impregnated cerium oxide.
To indicate wear of lower portion 18 to the user, a colorant is added to one or both of lower portion 18 and upper portion 20. The colorant or colorants are selected so as to provide a visual contrast between lower portion 18 and upper portion 20. Such contrast provides a visual indication to the user when lower portion 18 is worn away, or is otherwise sufficiently removed to no longer be desired for continued use in further polishing operations. For example, lower portion 18 can be rust in color, and upper portion 20 can be gray.
Secondary flutes 44 reduce the lower surface area and allow for an increase in the workload on the wheel by minimizing the square area in contact with the surface being polished. Such increase in the workload will allow the polishing operation to be accomplished faster. The arrangement of flutes as shown in the Figures also helps to more evenly distribute the polishing material across the polishing surface 26, to minimize distortion. One problem with prior art devices is that inexperienced users can apply excessive pressure and cause uneven polishing, and possibly distortion, to the glass. By providing an arrangement of polishing surface 26 as described above, less distortion and less uneven polishing results.
Body 112 includes a central axis 114 and a central passage 116 including a T-nut 146 which permits mounting of polishing wheel 100 to the rotating tool. Lower portion 118 includes a different color from upper portion 120. Body 112 includes a side taper 130 which tapers down to polishing surface 126.
In the illustrated embodiment, polishing wheel 100 includes a plurality of radially extending flutes 140 extending from central passage 116 to an outside edge of lower portion 118.
A further alternative embodiment of a polishing wheel 200 is shown in
Another alternative embodiment of a polishing wheel 300 is shown in
Polishing surface 326 of polishing wheel 300 includes a plurality of radially extending main flutes 340 extending from central passage 316 to an outer edge 338 of lower portion 318. Polishing surface 326 also includes a plurality of radially extending secondary flutes 344. Secondary flutes 344 extend from adjacent to, but not in fluid communication with, central passage 316. Secondary flutes 344 extend outward to outer edge 338.
Main flutes 340 include a width W1, and a depth D1 adjacent to central passage 316. At outer edge 338, the depth of main flutes 340 is reduced to depth D2 Main flutes 340 each have a variable depth portion 342 from depth D1 to D2. In the illustrated embodiment, the variable depth portion 342 has a curved surface 346. Exit passages 347 form reduced profile passages for the polishing fluid to exit out from wheel 300.
Secondary flutes 344 include a width W2, and a depth D3 adjacent to outer edge 338. Adjacent to central passage 316, the depth of each second flute 344 reduces from depth D3 to a zero depth where it terminates at polishing surface 326. Preferably, each secondary flute 344 includes a variable depth portion 348. In the illustrated embodiment, the variable depth portion 348 has a curved surface 350.
Referring now to
The recutting process can be repeated as the newly recut reduced profile portions 357 are worn away. For example, it is preferred that polishing wheel 300 can be recut at least twice, and more preferably more than twice, such as 3-5 times.
Any of the polishing wheels 10, 100, 200 described above can also be made in accordance with the flute features provided in wheel 300. Specifically, the materials, shapes and constructions including the attachment nuts can be used with the flute shapes and methods described with respect to
The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
The present application is related to application Ser. No. 11/240,129, filed Sep. 30, 2005, entitled, “Scratch Removal Device and Method”, now issued as U.S. Pat. No. 7,137,872, on Nov. 21, 2006.