US2718736A - Burnishing mat - Google Patents

Description

C. C. KINKER BURNISHING MAT Sept, 27, 1955 Filed June 12; 1955 Qwwmo o C/arence C. Amker l l l I United State t hfiQ" fljhis invention relates "to means forfburni h g j metal articles, and particularlyto a maflbrb ther me befrfh avi ing a rnulti'plicity of resilient projections ebnj-ifor nishing engagement'with the want?- i s'heretofore been proposedto prpvide a polishing "burpishiigg mat-in which theentireflbodylyzasirhade 91 an abfasive'impregnated 1 15515. ;The ab iasiyeimpi e gnated ubstance was molded into sheets or pads as fgw ell 'as into a'form' in which a of work contactung fingers extended 'from a main body. Ithas'been found that the elasticity.- of amubhersmass and especially a i i tt a atedteyetafla ii ;t aet -I Thus the ly reducedby the addition'of an abrasive.

known abrasive impregnated pads and projections above mentioned are useful only for the finishing of flat surfaces glglre the bending demands on the elements are not very The primary object of the present invention is the provision of a burnishing means of the class described which has only the surface portion of its resilient burnishing fingers or projections impregnated with an abrasive material, while the main bodies of the fingers or projections are of unimpregnated flexible material. The abrasive used may be of coarse or fine mesh, depending on the grade of burnishing to be performed, thus enabling workpieces to be successively burnished and polished by series of mats which, in succession, may have the resilient burnishing projections thereof impregnated with first a rough or coarse cutting abrasive, then with a fine cutting abrasive, and finally with a finishing burnishing material.

Further objects and advantages of the invention will be apparent from the following detailed description, and from the accompanying drawings illustrating one embodiment thereof, in which- Fig. 1 is a plan view of a mat embodying the invention mounted on a carrying member, with parts broken away, and with only a portion of the abrading projections shown, and

Fig. 2 is an enlarged fragmentary edge view thereof, taken on the line 2-2 in Fig. l, with some of the abrasive impregnated sleeves entirely or partially in central longitudinal section.

Referring to the drawings, 1 designates a mat or surface member that is mounted on a stifi" backing or carrying member 2 and having on its outer or exposed surface a multiplicity of rather closely spaced resilient fingers or projections 3 for rubbing or brushing engagement with metal articles to be burnished. In practice, either the articles, the mat, or both, may be relatively moved during burnishing operations.

The projections 3, and also preferably the mat member 1, are composed of resilient material, as for instance soft rubber, whereby the projections have yielding frictional coaction with the articles being burnished or polished.

The projecting fingers 3, in one embodiment that gives good results in practice, are approximately 2% inches long, circular in cross-section and are tapered lengthwise from a base radius of approximately of an inch to 2,718,736 a, liattg rrt ed Sept. 195,?

1 ere 5%; inch apart. These 'ineasiir'ements are mentioneii i 'n rei a filter and pump.

This use of fingers having impregnated surfaces has an advantage as it allows the successive use on the same work of a series of mats having different grades of impregnated abrasives so that one, for instance, may contain a rough cutting abrasive of about mesh, the next a medium coarse abrasive of, for example, 240 mesh, then an abrasive of, for example 325 mesh, and finally an abrasive suitable for the finishing operation, such as an air borne or flour size abrasive mesh.

We have found that rubber impregnated with an abrasive or other dissimilar hard materials is very brittle, the same as a rubber ink or pencil eraser, and thus entirely unsuited for use where great flexibility is a requirement because of its inherent inability to withstand rugged service and continuous flexing as is found where the work-pieces have domed or ridged or discontinuous surfaces that must be burnished.

The present invention is based on the provision of resilient fingers of mats of this character having only the working portions thereof provided with an abrasive impregnated coating or of a covering member impregnated with a suitable abrasive. This leaves the body of the burnishing finger, or at least the major portion thereof, composed of strong, durable, resilient stock, whereby breakage and deterioration in use are reduced to a minimum.

In practice, the object of the present invention is preferably accomplished by providing an abrasive impregnated sleeve or nipple 5 of soft rubber or the like, and fitting one of these sleeves over the Working end portion of each of the abrading fingers 3. The sleeve is preferably fixed in place by cementing or otherwise in such a manner that it can be removed only by immersion in a suitable solvent. These -sleeves preferably stop short of the base of the fingers so as to enable full advantage to be taken of the strength and resilience of the non-impregnated rubber stock at the base portions of the fingers where it is most needed. In event the abrasive impregnated portion of a finger is in the form of a sleeve or nipple that is fitted down over the finger, it is provided at its outer or blind end with a perforation 6 through which the entrapped air may escape. As wear in use occurs, the worn down sleeve portion may be removed from the flexible then substituted therefor on the finger.

I wish it understood that my invention is not limited to any specific construction, arrangement orform of the parts, as it is capable of numerous modifications and changes without departing from the spirit of the claims.

I claim:

1. In a burnishing mat or the like having aplurality of resilient rubber-like abradin'g'fingers, a' Sleeve ofpliant plastic material impregnated with abrasive material, fitted over and covering the burnishing end portionof each finger, and means to releasably, engage said impregnated sleeve and finger. p I

2. In" a burnishing mat or the like havinga base portion and a plurality of laterally spaced resilient rubberlike abrading fingers projecting outwardly from a surface of said base portion,'the provision of a sleeve of pliant plastic material impregnated with an abrasive material fitted over and covering the burnishing end portion of each finger in spaced relation to the base portion thereof,

wherebyeach finger has a neck portion at its inner end the flexing'pf which is not interfered with by its sleeve.

3. In a burnishing melt or the like having a base portion and a plurality of laterally spaced resilient rubberlike abrading fingers projecting outwardly from a surface of saidbase portion, the provision of a sleeve of pliant plastic material impregnated with an abrasive material fitted over and covering the burnishing end portion of each finger in spaced relation to the base portion thereof,

whereby each finger has a neck portion at its inner end angel 3 by applying a solvent and a new sleeve portion the flexing of which is not interfered with by its sleeve, each sleeve being releasably attached to its finger to permit replacement.

4. In a burnishing mat or the like having a base portion and a plurality of laterally spaced resilient rubberlike fingers projecting outwardly therefrom, said fingers each tapering so as to befredu'ced in size from near its inner end to its outer end, the provision of a sleeve of pliant plastic material impregnated with an abrasive fitted over the outer tapered end portion of each finger and terminating short of said base to provide a neck portion the resiliency of which is not interfered with by-the respective sleeve portion, said sleeve being releasably secured to the fingers for replacement.

References Cited in the file of this patent UNITED STATES PATENTS 963,523 Crismore July 5,1910 1,156,958 Whitin Oct. 19,1915 1,670,068 Grimes May 15, 1928 1,953,983 Benner Apr. 10, 1934 1,961,911 Pusch -June 5, 1934 2,049,324 Schneider July 28, 1936 2,083,749 Sword June 15, 1937 2,115,209 Mulholland et a1. Apr. 26, 1938 7 2,328,998 Radford Sept. 7, 1943 2,608,034 Frornson Aug. 26, 1952 FOREIGN PATENTS 451,704 Great Britain Aug. 11, 1936

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