US1578215A - Wire spoke - Google Patents

Description

March 23 1926. 1,578,215

E. W. STOLER WIRE SPOKE Filed April 1'7, 1923 avwmc 7% Patented Mar. 23, 1926 EDWARD W. STQLER, 0F MANSFIELD, OHIO.

Winn SPOKE.

Application filed April 17, 1923. Serial No. 632,680.

To all whom it may concern:

Be it known that EDWARD W. S'ronnn, a citizen of the United States of America, residing at Mansfield, in the county of Richland and State of Ohio, has invented certain new and useful .lmproven'ients in ire Spokes, of which the following is a specilication.

This invention relates to an improvement in spokes designed for use in wire wheels and the like, and is particularly directed to a method of forming the spoke to permit its yielding under load strains in a manner to avoid breakage.

The wire spoke of usual construction has a body or main length of uniform diameter throughout, and beyond such body is formed with somewhat enlarged terminal portions, one of which is headed and bent for cooperationwith the hub of the wheel, and the other of which is threaded for adjustable connection with the usual rim nipple. In the use of the wheel, the spokes flex in wardly and outwardly under the recurring load strains and relief therefrom, and as the body portion or main length of the usual constructions is of uniform diameter throughout, the flexing tendency and strain is transferred to the terminal portions, the bend, or the threaded portion, orall such parts, with a resultant breakage at one or the other of these points.

The present method of construction consists in forming the body portion or main length of the spoke of reversely-tapered formation from or about the center of such main length toward the ends thereof, this construction providing a gradual decrease in diameter of the body portion from one end toward the central point, and a gradual increase from such minimum diameter toward the opposite end.

lVith this formation, the central point of the body length of the spoke is weaker than the terminal portions, so that under the flexing strain and relief the strain is directed toward such central point. As this central point is farthest from the points of resistance, that is, the connected terminals of the spoke, the result is a gradual and uniform curving of the spoke length under the flexing movement, with materially less liability of breakage.

The invention is illustrated in the accompanying drawings, in which:

Fig. 1 is sectional View of a wire Wheel under ng the application of the spoke arnent in. a simple form, in order that flei'ing strain may be understood. K is an elevation of a conventional form of spoke, showing the line of bend or flexing when one end of such spoke is held and pressure is applied to the opposite end, to illustrate in a somewhat exaggerated manner the action of the spoke under working conditions.

Fig.- 3 is a- VlQ. of the improved spoke.

Fig. i is a view similar to Fig. 2, showing the results of a similar test on the improved spoke of this application.

The improved spoke 1 is .as usual constructed of appropriate material, formed at the hub end with an enlargement 2, headed at '3, and bent adjacent the head, as at 4. Beyond the enlargement the-spoke includes what may be termed the main length or body portion 5, the opposite terminal of the spoke being enlarged at 6, and threaded, as at 7. r

In the usual type of'spoke, indicated at 1, Fig. 2, the main length 5 is of uniform diameter, and under test, where one end of the spoke is held and pressure applied to the other end, to simulate actual use though in exaggerated form, the bending tendency is at the juncture of the body length 5 with one or the other of the enlarged ends 2 and 6. Thus a bending or flexing occurs in the instance illustrated, adjacent the enlarged end 2, as at 8. This continued bending or flexing at this point, which occurs in the actual use of the spoke, soon results in fracture of the spoke.

The improved spoke is shown in Fig. 3, and is distinguished from the conventional formation in the particular method of constructing the body portion or main length 5. In the improved construction, this main length is of usual strength of material, but is of minimum diameter at or about the center of such length, as at 9, and of gradually increased diameter from such point 9 to the terminal enlargements. Thus tne spoke isof weakest construction centrally of its main length or body portion, and load strains, this central point being the weakest will yield first to the flexing of the spoke. As this yielding is at a point farthest from the application of pressure, the spoke will yield in a uniform and large curve, as indicated at 10, Fig. 4. Thus no short bend strain is put on any portion of the spoke, and the flexing may continue for a much longer period than with the preferred forms vas previously constructed. The spoke of the improved form is thus of materially greater life than 'lorms heretofore used. 7

It is to be particularly noted that the main length 5 of the spoke is quite sharply reduced in diameter immediately adjacent the respective end enlargements 2 and '6, as clearly shown in Fig. 3, and that such main length is tapered toward its mid-length from each of these sharply' reduced portions. This particular construction of spoke body, including the sharply reduced portions adjacent the eulargn'ien'ts, is particularly important in lending to the spoke the desired resiliency at the central portion, for if the spoke was gradually tapered from the enlargements, instead of being sharply reduced as shown, the strain tendency would be all distributed at the point oi narrowest dimension of the spoke and under such strain a liability of breakage at this narrowest point might occur. With the sharply reduced portions adjacent the enlarged ones however, these particular points take care of some of :the strain and sufficient of said strain is transmitted to the narrowest part to absorb such strain and permit a resiliency of the central portion to avoid breakage.

The method of forming the spoke of the varying diameter may be mechanically carried out as preferred. However, it is believed that a simple and expeditious manner of securing this result is by swaging through a hammering toward the center, that is a series 01 hammers are arranged in radial lines on a chuck, with movements in and out toward the center, and by a constant hammeringo'f about nine thousand blows to the minute, the swaging on a tapered form is carried out. This method of swaging is usual and needs no further explanation.

The improved spoke is therefore designed for greater life than the usual spoke, by providing a weakened portion remote from the application of pressure, to insure a gradual and IDELXlHlIU'D curvature under flexing strains.

Attention is called to the act that because of the rapid, extensive and intensive hammering oi the metal to produce a spoke by the process herein described the same process will produce superior struts and bracing wires for aeroplanes because the size and weight is reduced in tapering same, while at the same time the tensile strength thereot is increased and maintained because of the amalgamation of the fibers of the metal produced by the intensive hammering process.

What is claimed as new, is 2- A wire spoke having enlarged terminals of substantially uniform diameter, and a main body length intermediate the termi nals, the body length being gradually tapered in both directions from said terminals, with :the tapering portions meeting at substantially the mid-length or" such body length.

In testimony whereof I afiix my signature.

,EDXVARD XV. STOLER.

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