US1924230A - Method of making bushings from strip metal - Google Patents

Description

Aug. 29, 1933. J. H. DAvl's- 1,924,230

METHOD OF MAKING BUSHINGS FRQM STRIP METAL Filed Jan. 14. y19:52 2 Sheets-Sheet 2 I Vfl {fg- (JH/WMO@ x Patented A ug. 29, 1 933 UMH-:Dr sTATlv-:s

METHOD OF MAKING BUSHINGS FROM STRIP METAL James Il. Davis, Dayton, Ohio, assignor to Moi rainc Products Company, Dayton, Ohio, a Corporation of Ohio Application January 14, 1932. Serial No. 586,509

4 Claims.

This invention relates to an improved method of rolling cylindrical forms from a strip of sheet metal stock while maintaining the blank integrally connected to the strip until the final forming 5 operation upon said blank.

An object of this invention is to provide such a method wherein the bushings formed thereby will have Acharnfered or otherwise finished ends which require no further trimming.

Patent No. 1,787,255 Klocke, issued December 30, 1930, discloses a method of forming bushings while maintaining the blanks integrally united with the sheet stock until the last forming operaation. This present invention has an important advantage over the method of this Klocke patent in the above-mentioned production of bushings with chamfered ends which require no further trimming, such as will be necessary in bushings formed by the Klocke method.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein ya preferred embodiment of one form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a strip of sheet metal stock from which bearing bushings may be formed by this invention.

Fig. 2 is a sectional view of the sheet stock and shows how the bearing blanks are successively partially cut from the main strip by the V-,shaped groove-forming dies.

Fig. 3 is a plan of the strip sheet showing the V-shaped grooves extending uniformly the full width of the strip.

Figs. 4, 5, 6 and 7 are transverse sections taken on lines 4 4, 5 5, 6 6, and 7-7 of Fig. 8, respectively.

4 Fig. 4 shows a section through the dies for shearing off the ends of the bushing blank tol 'sion of bushings to be formed. This metal strip l0 passes continuously over the lower die shown 65 in Fig. 9. The llat portion 11 of the lower die has a raised V-shaped wedge portion 12 which is directly aligned with a similar shaped reciprocating upper die 13. At each stroke of the press the die 13 descends and presses smooth V-shaped 70 grooves 14 and 15 in the upper and lower surfaces of the strip 10. These. grooves mark o ll the bushing blanks 16 but leaves them joined to gether throughout the full width of strip 10 by a relatively easily broken connecting web 17 (see Figs. 2 and 3). The grooved metal strip then advances over the portion 17 of the lower die `and at this station the upper reciprocating die 18 descends and ytrims off the'ends of each blank 16 to exact dimensions (see Fig. 4).

The strip then advances until the trimmed blank is in position over the portion 2l of the lowerdie and at this station the reciprocating upper die 22 descends and -gives the blank its initial forming as clearly shown at 20 in Fig. 5. When the ends of blank 20 are curled downwardly as shown, the connecting web 17 is easily progressively sheared or broken free from the next adjacent blank since this web 17 is quite thin.

The partially formed blank 20 next passes over the lower die portion 25 and at this station the reciprocating upper die 26 descends and forms the blank 20 into the open channel form 27 clearly shown in Fig. 6. During this forming operation the connecting web 17 is sheared olf for a further distance from both ends of the blank as will be readily understood from the drawings, but still leaving the channel form 27 integrally connected to the strip by a short length 28 of the web 17 which will be suilicient to 100 properly guide and support the channel form 27 as it is moved to its next station. l

The next and nal forming station is shown in Fig. 7. Here the channel form 27 has advanced to a position over the circular mandrel 30and 10 the upper and lower dies 31 and 32 have formed it into the circular bushing 35. At the time of this nal forming the connecting web 17 is `com-` pletely severed by the shearing action of the upper reciprocating die 31 and hence the formed 110 bushing 35 will drop from the end of mandrel 30 when the dies 31 and 32 recede and it is pushed endwise therefrom by the next advance of the succeeding channel form 27. This complete severance of web 17 is preferably made more positive or certain by providing a small drop or shoulder 40 (see Fig. 9) between the upper surfaces of die portion 25 and circular mandrel 30. The descent of die 31 will then obviously completely and positively sever the last remaining short length of the connecting web 17.

It is to be noted that the original V-grooves 14 and l5 form smooth bur-less chamfered end surfaces to the formed bushing 35 and hence no further trimming of the ends of the bushing 35 will be necessary. By this means the usual chamfering or other trimming or finishing operations on the ends of the bushings is entirely obviated and thereby the cost of manufacture is greatly reduced.

I have shown and described only one method of forming the transversely grooved strip into circular bushings for illustrative purposes. Obviously this invention is not limited to the specic number of forming stations or to the particular shapes of forming dies shown and described herein, as these may be greatly varied by those skilled in the art. An essential feature of the method of this invention is the step of pressing the transverse grooves in the strip stock and leaving a relatively weak connect-ing web between the blanks so that the finally formedr bushings will have chamfered or smooth finished ends such as will require no further trimming.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. In a method of making bearings, the steps comprising: marking off a bearing blank from a strip of sheet metal by a transverse groove extending only partly through the thickness of said blank, then curling the ends of said blank in progressive curling operations to form a bushing therefrom, said blank being, progressively sheared from said strip along said transverse groove by said progressive curling operations.

2. In a method of making bearings, the steps comprising: marking oi a bearing blank from a strip of sheet metal by opposed transverse grooves extending only partly through the metal thickness thus leaving an interconnecting web between said blank and strip, then forming said blank into circular form by progressively curling the two ends of said blank and simultaneously progressively severing said web of metal as said blank is shaped to circular form.

3. In a method of making bearings, the steps comprising: marking off a bearing blank from a strip of sheet metal by a transverse groove extending only partly through the thickness of said blank, forming said blank by transversely bending same into channel form and simultaneously progressively shearing said blank from said strip due to such bending, then severing said channel form from said strip and forming same into a closed circular bushing.

4. In a method of making bearings, the steps comprising: partially dividing a bearing blank from a strip of sheet stock by pressing V-shaped grooves into the metal but leaving a relatively easily severed connecting web between said blank and strip of stock, forming said blank into circular form by progressively curling the two end portions of said blank and simultaneously progressively shearing said connecting web by said progressive curling of said blank end portions.

JAMES H. DAVIS.

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