US2763354A - Sprags for one-way clutches - Google Patents

Description

Sept. 18, 1956 FIG.2. A

| T. SZADY 2,763,354

SPRAGS FOR ONE-WAY CLUTCHES Filed April 13, 1953 FIGJ.

I INVENTOR. LEOPOLD T. SZADY WAZ W ATTO RN EYS United States Patent SPRAGS FOR ONE-WAY CLUTCHES Leopold T. Szady, Hamtramck, Mich., assiguor to Formsprag Company, Van Dyke, Mich., a corporation of Michigan Application April 13, 1953, Serial No. 348,540

3 Claims. (Cl. 192-45.1)

The invention relates to one-way clutches including coaxial driving and driven rotary members having radially spaced concentric raceways thereon and a series of sprags interposed between said raceways. This application is a continuation in part of my application Serial No. 209,356 for Sprags for One-Way Clutches and Method of Forming the Same, filed February 5, 1951, Patent No. 2,715,262, August 16, 1955, the instant application being for the construction of sprags. With such clutch constructions, it is necessary to provide means for energizing the sprags or turning them so as to frictionally engage the raceways. This is sometimes accomplished by garter springs formed of helically coiled resilient wire which surrounds the series of sprags and engage properly inclined channels or apertures therein so as to impart to each sprag a torque stress. With certain constructions the garter spring receiving channels are formed in one or both ends of the sprag and usually subsequent to the severing of the sprags from a stock bar and the heat treatment for hardening the same. However, this requires not only a distinct mechanical operation but also the orienting of the separate sprags for feeding to the channel forming means.

It is the object of the instant invention to obtain a construction of sprag in which the garter spring receiving channels may be made in the stock bar prior to the severing of the sprags therefrom. To this end, the invention consists in the construction as hereinafter set forth.

In the drawings:

Fig. l is a side elevation of a sprag of my improved construction;

Fig. 2 is an end elevation thereof;

Fig. 3 is a plan view illustrating a method of forming the channel in the stock bar and then severing the bar into individual sprags;

Fig. 4 is a View similar to Fig. 3 illustrating a modified method for forming the channels in the stock bar and for severing the same into individual sprags;

Fig. 5 is a side elevation of the construction of sprag illustrated in Fig. 4; and

Fig. 6 is an end elevation thereof.

My improved sprag may be varied as to its cross sectional contour but, as specifically illustrated, this contour includes diametrically opposite eccentric cam portions A and B, a generally radial side C between said cam portions and an opposite side having oppositely inclined portions D and E extending to a central rounded nose portion F. The sprags may be formed from drawn or extruded stock bars having the cross sectional contour as just described and such bars are severed into suitable lengths for forming the individual sprags. However, before the severance of the sprags the bar is chan- 2,763,354 Patented Sept. 18, 1956 nelled and the channels are located to be at one or both ends of the severed sprags. The channels G- extend transversely across the sprag adjacent to one of the cam surfaces thereof and are inclined from the side C to the side portion E. Thus with a series of sprags in assembled relation to the other elements of the clutch, a garter spring N can be engaged with the channel of the sprag and will bear thereagainst at one side of the center of turning of the sprag so as to impart a torque stress thereto. This will energize the sprags to turn the cam faces A and B thereof into frictional engagement with the raceways on the driving and driven members. To retain the garter spring when once engaged, the chan nels G are undercut as indicated at H so that the resilient pressure of the spring against such undercut portion will hold it from endwise displacement.

In the method of forming the sprags, as above described, the stock bar I is advanced longitudinally step by step a distance equal to the length of the sprag plus the material removed in the severing of the bar. The channels G with their undercut portions H are formed by moving a suitable fashioned rotary cutter J transversely across the bar and through a path to give the proper inclination to the channel. The cross section of the cutter 1 corresponds in contour to the undercut portion H of the channel. The bar is severed into sprag lengths by a rotary cutter K and if desired this may be coaxial with the cutter I but projects beyond the periphery of the latter to extend completely across the bar. It will, of course, be understood that where both operations are performed simultaneously by cutters I and K on the same arbor it will be necessary to hold the bar from transverse displacement during this operation.

Sprags formed by the method above described only require heat treatment and hardening to complete the same and are then in condition for assembly in the clutch.

With the modified method illustrated in Fig. 4, a rotary cutter or grinder wheel L is fashioned to form the channels in the bar and this same cutter is used for severing the bar into individual sprags. In alternate operations of the cutter L, it is moved laterally different distances with respect to the bar M and intermediate each operation said bar is advanced an amount substantially equal to one-half the sprag length. Thus in one operation of the cutter L, it is moved to form a channel G in the sprag and in the alternate operation it is moved completely across the bar ot sever the sprag therefrom. As the advancement of the bar is between each operation of the cutter, the channel will be located centrally between the ends of the severed sprag.

One of the important advantages of the construction of sprag as above described is that it is capable of being formed by the method described which latter forms the subject matter of my application, Serial No. 209,356, Patent No. 2,715,262, August 16, 1955. In addition to this, the construction in both of its modifications respectively illustrated in Fig. 1 and Fig. 5 has the channels for receiving the energizing garter spring formed in one of the cam faces of the sprag. Thus the garter spring may be engaged with the series of sprags peripherally in the construction of Fig. 5 or either peripherally or endwise in the construction shown in Fig. 1.

What I claim as my invention is:

1. A sprag for one-way clutches having diametrically opposite eccentric cam faces, one of said faces having a transversely extending channel therein open radially out- References Cited in, the file of this patent UNITED STATES PATENTS. [2,364,280 Dodge Dec. 5, 1944 10 4 Dodge Sept. 17, 1946 Davis Oct. 25, 1949 Turner Oct. 9, 1951 Turner June 3, 1952 FOREIGN PATENTS Australia Sept. 6, 1949

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