US 2751664 A
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Description (OCR text may contain errors)
June 26, 1956 ARNlT 2,751,664
METHOD OF MAKING BALL CARRIERS Filed Oct. 29, 1952 United States Patent Cfiice 2,751,664 Patented June 26, 1956 METHOD OF MAKING BALL CARRIERS Fred H. Arnit, Mount Prospect, 111., assignor to Garden City Plating & Manufacturing Co., a corporation of Illinois Application October 29, 1952, Serial No. 317,559
3 Claims. (Cl. 29-148.4)
This invention relates to a method of making ball carriers for antifriction bearings, and is particularly concerned with the progressive shaping of a metal strip and assembly of a plurality of ball bearings with the metal strip prior to the final forming operation.
.The present method is particularly designed to make ball carriers for the antifriction bearing described in my copending application filed concurrently herewith.
In accordance with the present invention a strip of metal is run through a series of dies to bend it from a fiat strip into tubular form with infolded edges, and, concurrently with the forming operations, a series of apertures, is blanked out of the strip and a ball is inserted within the tubular member adjacent each aperture prior to the final forming operation which is effective to retain the ball bearings in rotatable relationship to the tubular member.
The method of making ball carriers is applicable to metal strips of predetermined length or to a continuous strip. The present method is advantageous in that it reduces the expense of making ball carriers by speeding up the manufacture and reducing spoilage. In addition, the balls are held in position within the carrier more securely than in similar devices previously known. The steps comprising the method by which the above and other advantages are attained will be described in the following specification, taken in conjunction with the accompanying drawing, showing a preferred illustrative embodiment of the method constituting the invention, in which:
Fig. 1 is a fragmentary perspective view of a ball carrier made in accordance with the invention;
Fig. 2 is a fragmentary top plan view showing a strip of metal in various stages of the process;
Fig. 3 is a fragmentary side elevational view, similar to Fig. 2, showing some of the apparatus diagrammatically;
Fig. 4 is a cross sectional view taken along the line 4-4 of Fig. 3;
Fig. 5 is a cross sectional view along line 5-5 of Fig. 3;
Fig. 6 is a cross sectional view along line 6-6 of Fig. 3;
Fig. 7 is an enlarged fragmentary top plan view of a a portion of the metal strip after the punching operation;
Fig. 8 is an enlarged fragmentary top plan view of the strip after the projections adjacent the aperture have been bent into ball retaining position;
Fig. 9 is an enlarged side elevational view of a portion of the strip, showing the shape of the strip at the time of the ball inserting step;
Fig. 10 is a cross sectional view taken along the line 10-10 of Fig. 7; and
Fig. 11 is a cross sectional view taken along the line 11-11 of Fig. 8.
Referring to the drawing, a flat strip 2 of metal being fed intermittently towards the right, as viewed in Figs. 2 and 3, is bent upwardly, as indicated at 3, along its longitudinal edges. The edges 3 are then bent inwardly into juxtaposition with the upper face of the metal strip, to form doubled edge. portions as indicated at 4. The edges 4 are comparatively narrow so that a substantial portion 5 of the metal strip 2, disposed centrally of the edges 4 is of single thickness. The bending operations are performed by rollers or any other suitable forming tools while the strip is moving.
At timed intervals the feeding motion of the strip is halted for a short pause, and a punch 6 moves downwardly during the pause. to blank out an aperture 7 in the central portion 5 of the strip. The opposite ends of aperture 7 are semicircular, as indicated at 8, and are connected by undulating lines 9 which provide projections 10 extending inwardly towards the longer axis of the aperture 7.
Another punch 11, is spaced from the punch 6 laterally a distance equal to the distance the strip 2 is fed between the timed pauses. The punch 11 is activated simultaneously with punch 6 and operates to bend the projections 10 downwardly at a slight angle, as indicated at 12, during the same pause in which the punch 6 is blanking out the next successive aperture 7. It is obvious that the punches 6 and 11 need not be positioned to opcrate on adjacent apertures, but may be spaced two or three times the distance between apertures so long as the distance between the punches is a multiple of the dist'anee between adjacent apertures.
After the strip passes the work station at which the punch 11 is located, it is bent upwardly along its longitudinal center line, as indicated at 13, to form a troughlike structure with the edges 4 facing each other. A ball dispenser 14 is spaced laterally from punch 11 a distance equal to the distance the strip moves between pauses, and at each pause the dispenser drops a ball 15 into the aperture which is positioned below the dispenser during the pause. The dispenser 14 may be controlled automatically by mechanical or electronic means, or may be operated manually. The diameter of the ball is slightly greater than the width of the aperture 7 so that it is retained therein as the metal strip moves to the right, and the bending along the longitudinal center line is continued until the edges 4 are juxtaposed in face to face relationship and the strip has been formed into a tubular member with a ball 15 positioned adjacent each aperture 7. If a continuous strip of metal is used in the process, any suitable cut-01f tool may be used to cut the ball carriers into desired lengths.
The ball 15 is slightly greater in diameter than the distance between the inner ends of the edges 4 and the upper edge 16 of the completed carrier, as shown in Fig. l. The ball is also larger than the distance between the side walls 17 of the carrier and, accordingly, projects laterally and vertically from the carrier. The projections 10 are shaped to conform to the curvature of the ball and hold the ball securely within the carrier while permitting it to rotate freely therein. Thus it will be seen that the projecting surface of the ball 15 provides a rolling contact with any surface with which it comes in contact.
Although I have described a preferred method constituting my invention in considerable detail, it will be understood that the method described is intended as an example, as many details may be modified or changed without departing from the spirit or scope of the invention. For example, the apertures may be blanked out before the edges are bent inwardly, or the projections may be bent downwardly in the blanking operation. Accordingly, I do not desire to be restricted to the details or exact sequence of steps described.
I. A method of making ball carriers comprising the steps of bending the longitudinal edges of a metal strip upwardly and inwardly into juxtaposition with the body portion of said strip to form doubled edge portions, blanking an aperture in the center portion of said strip, bending said apertured strip progressively along its longitudinal center line, positioning a ball bearing larger than the width of said aperture on said strip with a'portion of its peripheral surface projecting through said aperture, and continuing bending of said strip around said ball bearing to form a tubular member with said doubled edge portions juxtaposed, and said ball bearing rotatably-retained in said tubular member, with a portion of its peripheral surface projecting through said aperture, by said doubled edge portions and the edges of said tubular member contiguous to said aperture.
2. A method of making ball carriers comprising the steps of bending the longitudinal edges of a metal strip upwardly and inwardly into juxtaposition with the body portion of said strip to form doubled edge portions, blanking an aperture in the center portion of said strip, the configuration of said aperture providing a plurality of projections extending from the edges of said aperture towards the opposite edge thereof, bending said projections downwardly at a predetermined angle, positioning a ball bearing on said partially bent strip with a portion of its peripheral surface projecting through said aperture, and then bending said strip upwardly around said ball bearing to bring said doubled edge portions in juxtaposition and to retain said ball bearing in position with a portion of its peripheral surface projecting through said aperture.
3. The method of making a ball carrier which comprises feeding a metal strip intermittently past a plurality of 'work stations and simultaneously bending different portions of said metal strip, one of said bending operations being effective to double the longitudinal edges of said strip inwardly and the other being efiective to bring said doubled edges into juxtaposition to form said metal strip into a tubular member, blanking an aperture in the center portion of said strip and simultaneously forming projections extending laterally from the edge of said strip adjacent said aperture, bending said projections downwardly at a slight angle, said blanking and last mentioned bending operation being done intermediately of said first and second mentioned bending operations, and positioning a ball bean'ng'in said partially formed tubular member with a portion of its peripheral surface projecting through said aperture prior to the completion of said second mentioned bending operation.
References Cited in the file of this patent UNITED STATES PATENTS Quarnstrom Nov. 25, 1952