US1016068A - Process of manufacturing brake-shoe keys. - Google Patents

Description

YTH. G BRAKE SHOE KEYS.

Patepted Jan. 30, 1912.

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Xmmmkn muuuy l W. D. F PROCESS 0F MANUPAGT I APPLICATION FILEDVOOTI, 1910. 1,01 6,068.

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WILLIAM n. ronsYTH. Yor YoUNesTo-wn, onto'.

vrnocnssl F MANUFACTURING BRAKE-snor. KEYS.

Speciicaton of Letters '.Patent.

' Patented Jan. 30,1912".

Application led October 31, 1910. ,A Serial No. 589,966.

be effective in producing brake-shoe keys yat minimum cost.

In the accompanying drawing, Figure l Ais a plan view of a key-blank cut from the rolled bar. Fig. 2 is a side elevation of the same. Fig. 3 is a cross section of the rolls to form rolled bars such as shown foreshortened in Fig. 5. Fig. 4 is a side elevation of a completed brake-shoe key. Fig. 5 is a foreshortened plan of the rolled bar from which the key blanks are cut. Fig.-6 is a longitudinal section on the line 6-6 of Fig. 5. Fig. 7 is a foreshortened plan view of a portion of a development of the peripheryy of one of the rolls by which the bar shown in Fi-g.,5 is rolled. Fig. 8 is a cross section of this roll on the line 8-8 of Fig. 7. Fig. 9 is a left end view of the key shown in Fig. 4.

Similar reference characters refer to like parts throughout the -several views.

The usual manner of' producing brake-shoeV keys is to form abar of even cross-section into a'wedge and then trim oft1 the edges of the wedge until the proper width is attained. This results in waste, firstV because the key is of unnecessary'weight; and second, the metal trimmed from the wedges is of less value per pound than the original material. The process employed to form the key shown in Figs. 4 and 9., as hereinafter described, results in no waste of material by trimming, and avoids unnecessary weight in the finished key. While keys have been cast in proper form, cast keys are either too expensive or worthless.

The process forming the basis of this invention consists in rolling a bar l by means unique rolls, shearing the bar to form blanks 2, and then bending the blanks to form keys The rolls for formino' the bar shown in Figs. 5 and may be of any proper diameter, so long as the circumference of the grooving roll equals a multiple of double the length of a key blank. One roll is formed with the usual groove and the other with the .circumferential rib,l employed to produce -barsv of exact sizes. The bottom of the groove of one roll or the top of the rib of the other roll' is formed with projections or dies 3, which are diamond-shaped in plan and substantially*semi-circular in cross section at their middle portions. ln the drawings, `the projections are shown at the bottom of the groove. These projections taper toward their ends, not because the radial height ofthe projections changes, but because the radial heights of the bottoms of the spaces between the projections and the walls 14 change.

Considering the circumference of the cylindrical portion 4 of the roll 5 of Fig. 3, developed into va plane 9, Figs. 7 and 8, then the highest surface of the projections 3 will form a line 10, in Fig. 8. On each sideof these projections are inclines 11.. The opposite roll 12 has a cylindrical projection 13 which enters between the walls 14 of the groove in the first roll, and in the development in Fig. 8, forms the dotted line l5.

When a bar of metal of suii'icient size is passed between the rolls, the edges will be formed into two consecutive series of in clines 16, 5 and 6) which inclines are f separated .by round-bottomed grooves 17 having tapering ends, whose deepest depressions are at .the apexes of the inclines. T he blankbar lis then formed at one pass through the rolls. The blank-bar l is next sheared trans,-

versely at the tops and bottoms of the inclines 16,:on the lines Lf-a and b-b, Fig. 5, thus forming the blanks 2, having a thin lower end, 'and a thick upper end which is provided with a groove 19. The blank is then bent to conform to the curve of the brake-shoe and to produce a head 20. There is no waste of material either in the forming of the key 7, nor in the key itself, and as all the steps may be carriedout by means of machines, the labor cost is very small.

The form of the rolls, the depth and cross section of the groove, and the general proportions may be changed without departf ing from the spirit of my invention.

Having now explained my process, what I claim as my invention anddesire to secure by Letters Patent is The process of manufacturing Abrake-shoe keys'wln'ch consists in so rolling a bar as to `inclines, and semi-circuler, tapering, 1ong i' tudina-l grooves Whose deepest depresslons are "at 'the apexes Of sald lnclinesythenshearlng form on one of its Surfaces a' plurality of e predetermined curvature and toform a conseeutve nclines ascending and descending from apexe's located at the` endsof said said bar transversely at the apex .of said inclines and again. midway between the apexes ,f said nclines to form key-blanks;

and then bending blanks so as to give them heed at the thick end. I

,In testimony whereof, I have signed this specication in the presence of two subscrb ing Witnesses.

l VILLIAM D. F ORSYTH. In the presence of A l ELIZABETH M. BROWN,

GEORGE T. WILSON.

Copies ofthis patent may be obtanedfor live cents each, by addressingthe Comnrissier of Patents. t Washington, D. C.

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