US2370490A - Polishing or buffing pad - Google Patents

Description

Feb. 27,1945. G. D. RICE I 2,370,490

POLISHING OR BUFFING PAD v I Filed Oct. 22, 194

B v P s Q/ r flwm. CAT-r0%y s atented Feb. 27:, 1945 UNITED STATES PATENT orrica POLISHING R BUFFING PAD George D. Rice, Chicago, Ill. Application October 22, 1942, Serial No. 462,917

13 Claims.

The invention has for its aim the provision of an improved form of polishing or bufllng device of the type employed in finishing and polishing the irregular surfaces of dental plates and other surfaces of varying contours, and commonly called bufilng cones.

Prior bufiing devices of this general class have been made of felt, and, in some instances, it has been necessary on account of difficulties experienced with felt to resort to the use of a cloth wound or wrapped upon a mandrel. Felt bufling cones have proven unsatisfactory because they are not suiliciently flexible for many uses. Moreover, metal particles tend to become embedded in the material, with the result that an undesirable abradingor cutting action is produced; and the felt is apt to become grooved.

With the foregoing in view, the primary object of my invention is to provide a polishing device possessing a high degree of flexibility so as to be capable of conforming readily to irregular shapes and surfaces, which has an ability to retain an abrasive but to shed relatively heaviermetallic particles, and which is capable of withstanding long and hard usage.

Another object is to provide a polishing device of the character indicated which may be produced at a very low cost.

Another object is to provide .a polishing device in the nature of a bull or cone composed of a plurality ofplies of flexible material, such as cloth,

securedtogether along the axis of a supporting I mandrel and providing wing portions adapted to flex reversely in the unidirectional rotation of the mandrel with the wing portions engaging diametrically opposite sides of an internal annular surface of relatively small diameter.

The objects of the invention thus generally stated, together with other and ancillary advantages, are attained by the construction and arrangement shown by way of illustration in the accompanying drawing, wherein Figure l is a side elevational view, and Fig. 2 an end view of the improved polishing device, the supporting mandrel in the case of Fig. 2 being shown in section.

Fig. 3 is a perspective view on asomewhat enlarged scale illustrating the shape which the device tends to assume in use.

Fig. 4 is a side view of a slightly modified form.

Fig. 5 is a fragmentary perspective view of still another form of the device.

The improved device consists of a multiplicity of layers or plies 1 of cloth or other flexible material arranged in the form of a pile or stack and held or secured together along a central axis so as to form diametrically opposed wing portions 8 and 8. Thus the device is in the nature of a pad of substantial thickness. As shown in Figs. 1 and 2, the plies I are fastened centrally thereof by two rows 9 of stitching which extend generally lengthwise of the pad and are spaced apart so as to provide a central mounting or hub portion In which when split or divided centrally forms a longitudinal or axial recess or pocket H for the reception of a mandrel a. Preferably the rows 9 converge at or near the outer end of the pad so that the hub and recess are conical in form.

Also, as shown'in Figs. 1 and 2, the plies may be secured together at their inner edges by rows of stitching l2.

the mandrel is tapered and externally screw threaded as shown in Fig. 1. Since the device is customarily rotated at extremely high speeds when in use, the location of the pocket centrally of the pad, with opposite wing portions accurately balanced, is very important.

The pad may be of any suitable or preferred shape. As herein shown it is generally rectangular in form, with the outer corners of the plies cut off as indicated at l3 to produce a-somewhat tapered tip portion. The wing portions 8 and 8 maybe of varying widths depending on th use to which the device is to be put, and the same is true as to the thickness, variations being obtained by employing difierent numbers of plies. It should be observed, however, that in practice the device is usually rotated at extremely high speeds so that it is very important that the pad and its rotary support be symmetrical with respect to the rotational axis of the device.

While various materials may be used, ordinary cloth such as muslin is preferred for many uses.

To facilitate division of the plies within the hub III to form the recess II, the central ply l4 may be made of contrasting color.

' When the pad is rotated by its supporting mandrel, the outer edges of the plies 1 engage with the work and, as an incident thereto, the wing portions 8 and 8 bend or flex reversely after the fashion of the leaves of a book, thereby producing broadened edge portions substantially brush-like in character which constitute the main polishing surfaces of the device. It has been found that the edges ofthese wing portions are capable of retaining an applied abrasive effectually, but at the same time have the capacity of throwing oil heavier particles of metal or other material being I operated upon.

For some purposes, as when polishing concave or internal conical surfaces it is desirable that the body assume a conical form in use. This result is obtained especially in the case of relatively wide pads through a spiraling action of the reversely bent wing portions 8 and 8 (Fig. 3) which is induced by the convergence of the rows 9 of stitching, and is moreover promoted by the tapering tip portion I3. The same effect is also obtainable by the use of parallel rows of stitches 9 (Fig. 4) terminating short 01' the tip end of the pad and preferably connected by a transverse row 9. It will of course be understood that when the pad is used for bufling or polishing the internal surface of a cylinder of a diameter substantially less than the width of the pad, the reverse- 1y flexed wing portions 8 and 8 will, when properly dimensioned with respect to the size of the cylinder, assume an annular or cylindrical form. In practice, the size and shape of the pad is determined by the nature of the particular bufling or polishing operation to be performed.

As illustrative of the use of different materials employed, in Fig. I have shown a pad composed in part of ordinary fabric to form plies 1 and in part of intervening lies I of'hair cloth. In use the warp threads of the hair cloth become disengaged and are thrown free, leaving the ends of the weft threads exposed so s to form in effect bristle-like edge portions l5. 0th materials of varying degrees of hardness or sti ness or having an abrasive effect, such, for example, as paper,

wool, emery cloth and the like, may be used. The

plies may be fastened or held together by means varying to some extent according to the material employed in makingthe plies. In the case of cloth, stitching has proven very efiectiveand is inexpensive. Moreover, this form of fastening is advantageous as compared to mechanical clamps which are apt to involve the use of eccentrically disposed parts which, being out of balance, are highly objectionable because of the extremely high speeds at which polishing devices are driven.

A feature of the improved pad of primary importance is its flexibility, rendering it adaptable to many and varied uses and to the attainment of results which are impossible of attainment with prior polishing or bufling devices.

It may be made easily and cheaply, in many different sizes according to the size and nature of the work. For example, a pad of the character has proven very effective in removing burrs on the interiors of shells in the manufacture of munitions, in the case of which the use of prior bufling devices has resulted in a high percentage of rejections. It has also proven especially advantageous in polishing irregular surfaces such as I those encountered in dental plates.

I claim as my invention:

1. A bufling or polishing pad composed of a multiplicity of plies of flexible material such as cloth fastened together along a central longitu-. dinal axis and adapted to be mounted upon a rotatable mandrel, said plies providing wing portions projecting radially outward from said axis substantially equidistantly and adapted to bend reversely when carried into engagement with a workpiece upon the unidirectional rotation of the mandrel.

2. A bufling or polishing pad comprising a multiplicity of layers of cloth or the" like having spaced rows of stitching extending longitudinally of the pad substantially centrally thereof, said rows being spaced apart sufllciently to Permit the insertion of a mandrelbetween' two of the plies centrally of the pad, said pad providing opposed wing portions'adapted to fold reversely so as to assume a substantially annular form as an incident to simultaneous engagement with diametrically opposed surfaces upon the unidirectional rotation of the mandrel.

3. A bufling or polishing pad comprising layers ofcloth or the like having spaced rows of stitching extending longitudinally of the pad, said rows being spaced apart sufliciently to permit the insertion of a mandrel between two adjacent plies centrally of the pad and being inclined relative to each other so as to converge toward the tip end of the pad.

4. A bufl'ing or polishing pad comprising a plurality of layers of cloth or the like having spaced substantially parallel rows of stitching extending longitudinally of the pad substantially centrally thereof, said rows of stitching terminating short of the tip end of the pad, and forming between the central layers a pocket for receiving a supporting mandrel. v

5. A bufling or polishing device comprising a plurality of plies of flexible material stacked one upon the other to form a pad, and means fastening said plies together centrally of the pad and along spaced longitudinal lines to permit of the insertion of a supporting mandrel between cen-v tral plies along the longitudinal axis of the pad, said pad providing radial wing portions each adapted to flex reversely as an incident to em gagement with the work upon unidirectional rotation of the mandrel.

6. A device for polishing or bufllng internal surfaces, comprising a pad composed of a plurality of layers of flexible material such as cloth and adapted to be mounted upon asupporting mandrel with wing portions formed by said plies extending radially from the mandrel, said plies being secured together only adjacent the mandrel so as to be slidable relative to each other whereby when the pad is inserted into a workpiece of an internal diameter substantially smaller than the width of the pad, said wing portions are capable offolding reversely upon themselves in the unidirectional rotation of the mandrel.

7. The combination with a mandrel having a tapering screw threaded end portion, of a polishing or bufling pad composed ofa plurality of layers of flexible material and having an axial pocket between adjacent layers, said pocket being conical in form to receive said tapering mandrel, the

mandrel being screw threaded into driving en gagement with the walls of the pocket.

8. A device of the class set forth comprising, in combination, a. support to be mounted for rotation about a longitudinalaxis, and a polishing element mounted on the support and having wing portions extending lengthwise of the support and projecting radially therefrom, said element and its support being symmetrical with respect to the rotational axis of-the device whereby to secure I substantial dynamic balance.

9. A polishing or bufling device in the form of a flat pad composed of a plurality of piles of flexible material, said plies being secured together to provide an elongated pocket between adjacent ones of the plies with wing portions extending radially from opposite sides of said pocket, the plies in said wing portions being slidable relative to each other to permit the wing portions to fold reversely upon contact with a workpiece when the pad is rotated about the axis of said pocket.

10. A polishing or bufiing device in the form of 1 a pad comprising a plurality of flat plies of flexible material assembled in face-to-face relation and having an elongated pocket formed between adjacent central plies, said pocket being open at one end for the reception of a supporting mandrel.

11. A polishing or bufiing device in the form of a flat pad composed of a plurality of plies of flexible material and having an elongated pocket for.

receiving a supporting mandrel, said pocket being formed between two adjacent plies and having its long? idinal axis disposed in a common plane with the fiat pad.

12. A polishing or buffing device comprising a plurality of plies of flexible material stacked one upon the other to form a pad adapted to be rotated about a central longitudinal axis disposed in the plane of the pad, said plies being shaped to provide a tapering tip at one end of the pad adapted to facilitate the flexing of the plies when the pad is inserted in a cylindrical work piece of a diameter less than the normal width of the pad.

13. A thin flat polishing device of flexible material adapted to be supported for rotation about a centrally disposed axis substantially in the plane .of the device and presenting radially disposed wing portions engageable with opposite sides of an internal cylindrical surface, said wing portions being tapered at one end to facilitate reverse'flexing thereof upon insertion of the device in the work.

GEORGE D. RICE.

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