Abrading – Abrading process – Utilizing nonrigid tool
Reexamination Certificate
1999-10-27
2001-04-24
Rose, Robert A. (Department: 3723)
Abrading
Abrading process
Utilizing nonrigid tool
C451S168000, C451S049000, C451S336000
Reexamination Certificate
active
06220940
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a micro-finishing apparatus capable of providing continuous through-feed. More specifically, this invention is used to place a repeatable micro-finish on cylindrical workpieces having a relatively small diameter.
BACKGROUND OF THE INVENTION
Micro-finishing is a surface finishing process wherein an abrasive is brought to bear against a workpiece having a rough outer surface. By improving the surface finish, less friction will be produced between the workpiece and any contact surface thereby extending the life of the workpiece. Non-metallic products, such as wood, glass, rubber and plastic can also be micro-finished.
How a workpiece is micro-finished depends on its shape and size. Viewing
FIGS. 1-4
herein, “centerless” or “center” operations dictate how a workpiece is held in place during the finishing process. Center operations are appropriate when the workpiece is large enough in diameter and length to be supported at each end for rotation, such as with a chuck on a lathe. However, when the diameter or the length of a workpiece is too small to be supported by a lathe, centerless operations may be used by placing the workpiece, for example, between two rotating rollers, as seen in
FIGS. 2 and 4
.
In addition, a workpiece contacts the abrasive either through “plunge” or “transverse” operations. A workpiece is subject to finishing by plunge operations when the workpiece's length is less than or equal to the width of the available abrasives. The entire length of the workpiece is constantly in contact with the abrasive. Transverse finishing is used when the workpiece is longer than the width of any available abrasives. In which case the abrasive must travel along the longitudinal axis of the rotating workpiece as it micro-finishes.
It is therefore well known in the art that the shape and size of the metal product will determine which one of the various micro-finishing machines would produce the best finish: 1) plunge-center; 2) plunge-centerless; 3) transverse-center; or 4) transverse-centerless.
For purpose of this invention, it is important to expand upon the typical transverse centerless micro-finishing machine known in the art. When cylindrical metal workpieces are micro-finished using the transverse centerless micro-finishing type machine, the workpieces are placed between two rollers as seen in FIG.
4
. The rollers are located beneath the abrasive and are offset at an angle for feeding the part through the micro-finishing apparatus. Hence, this process is also often referred to as “through-feed centerless” micro-finishing. The rollers rotate in the same direction very quickly, thereby rotating the part along the abrasive. Problems occur when workpieces are very small, such as those having diameters less than {fraction (
3
/
8
)} of an inch or 8 millimeters. Particularly, transverse centerless cylindrical workpieces are difficult to micro-finish, if not impossible for small parts, because the abrasive cannot reach the small workpiece positioned between the rollers. This is due to the large difference in diameter between the rollers and the workpiece. More specifically, the diameter of the workpiece is so small that the abrasive contacts the rollers and never reaches the workpiece positioned therebetween. Also, conventional methods of holding the workpiece during finishing, such as using a lathe, cannot be used because the workpieces are just too small to be held by the chuck.
Art in the field may also be directed to grinding machines, as opposed to micro-finishing machines. Typical grinding machines are shown in
FIGS. 5 and 6
. These machines are comprised of a regulating mechanism, an abrasive and a means of supporting the workpiece at a fixed location. However, none of the grinding machines in the art can be used to solve the problem of micro-finishing miniature cylindrical workpieces. Problems exist in traditional grinding processes because of the abrasive used. In traditional grinding processes, the abrasive is a wheel or continuous belt that travels very fast, constantly being reused. As a result, the finish varies as the abrasive wears. Also, the contact surface of the abrasive is short if a plurality of workpieces are continuously fed through typical grinding machines. The preferred apparatus should repeatably produce consistent micro-finishing results to the entire outside surface of very small centerless workpieces.
In summation, there is nothing currently in the art capable of micro-finishing small workpieces. The purpose of this invention is to provide an apparatus that can micro-finish the outer surface of very small cylindrical workpieces with repeatability and consistency.
SUMMARY OF THE INVENTION
The present invention is directed to a micro-finishing apparatus, satisfying the need for finishing small cylindrical workpieces. This is accomplished by feeding the workpiece through two planar surfaces, one surface being a regulating mechanism and the other being a micro-finishing spool drive mechanism. The regulating mechanism rotates the workpiece against the abrasive of the micro-finishing spool drive mechanism and feeds it through the apparatus.
More specifically, this invention comprises a regulating mechanism having a planar contact surface for rotating the workpiece. The micro-finishing drive mechanism advances a roll of non-continuous abrasive belt over a planar grinding work face, which is substantially parallel to and forms an opening with the planar contact surface of the regulating mechanism. The invention also comprises a guide bar that passes through the opening and traverses at an angle between the planar contact surface of the regulating mechanism and the planar grinding work face of the micro-finishing drive mechanism.
Accordingly, it is an object of the present invention to provide a micro-finishing apparatus that is capable of micro-finishing small cylindrical workpieces that cannot be micro-finished on center machines or machines that support a workpiece on rollers.
Another objective of the present invention is to provide a micro-finishing apparatus that provides repeatability in finishing results by always introducing the workpiece to new abrasive.
Still another objective of the present invention is to provide a micro-finishing apparatus that more efficiently utilizes abrasive material by moving the abrasive at a very low rate of speed.
Another objective of the present invention is to provide a micro-finishing apparatus that can adjust to accommodate cylindrical workpieces of various diameters.
Further, another objective of the present invention is to provide a micro-finishing apparatus that has continuous through feed so that a plurality of workpieces can be micro-finished without constant and direct manual intervention.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims.
REFERENCES:
patent: 1281366 (1918-10-01), Heim
patent: 1932092 (1933-10-01), Hijo
patent: 3271909 (1966-09-01), Rutt et al.
patent: 3732648 (1973-05-01), Shaller
patent: 3909986 (1975-10-01), Miyazawa et al.
patent: 5437125 (1995-08-01), Barton, II
patent: 5683291 (1997-11-01), Humpert et al.
patent: 5695391 (1997-12-01), Steinwender
patent: 5766057 (1998-06-01), Maack
patent: 5803796 (1998-09-01), Barton, II
patent: 5863239 (1999-01-01), Barton, II
patent: 5913716 (1999-06-01), Mucci et al.
patent: 0504355 (1930-08-01), None
patent: 2254643 (1974-05-01), None
Grinding Equipment & Machinery Co., Inc.
Herberger Robert J.
Rose Robert A.
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