US627597A - Means for attaching sprocket-wheels to crank-shafts. - Google Patents

Description

\ No. 627,597. Patented June 27, I899.

B. W. SCOTT. MEANS FOR ATTACHING SPROCKET WHEELS T0 CRANK SHAFTS.

(Application filed Aug. 26, 1898.)

[No Model.)

Y Z %VTOR.

I I 'f Attorneys.

a yL/K a UNITED STATES PATENT OFFICE.

BURTON w. scoTT,- or DETROIT, MICHIGAN.

MEANS FOR ATT'ACHING SPROCKET-WHEELS TO CRANK-SHAFTS.

SPECIFICATION forming-part of Letters Patent No. 627,597, dated June 27, 1899.

Application filed August 26, 1898.

To all whom it may concern:

Be it known that I, BURTONNV, SCOTT, a citizen of Canada, residing at Detroit, in the county of Wayne, State of Michigan, have invented certain new and useful Improvements in Means for Attaching Sprocket-\Vheels to Crank- Shafts; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to whichit appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon,which form a part of this specification. I

This invention relates to means for attaching the sprocket-wheel to the cank-shaft of a bicycle; and it consists in the construction and arrangement of parts hereinafter more fully set forth.

The object of the invention is to provide simple and efficient means for securely attaching the sprocket-wheel to the crank-shaft in such manner as to enable said sprocketwheel to be readily removed, the arrangement being such that the operation of securing the sprocket-wheel upon the shaft also looks one of the-bearing-cones and secures the crank in place. This object is attained by the mechanism illustrated in the accom:v panyin g drawings, in which- Figure l is a sectional view through the crank-hanger, bearing,-and sprocket-wheel of a bicycle, the shaft and bearing-cones being in elevation and a portion of the crank and shaft being broken away. Fig. 2 is-an elevation of the end of the shaft and cone, showing the milling on opposite sides of the shaft and by dotted lines the locking-wedges lying thereon. Fig. 3 is an elevation of the hub of the sprocket-wheel looking from the inner side, showing the beveled recesses in the bore which receive the locking-Wedges. Fig. 4 is an elevation of said wedges, showinga side, end, and plan view thereof.

Referring to the letters of reference, A designates the barrel of an ordinary crankhanger, in which are the ball-cases A, carrying the balls A".

B designates the crank-shaft, having the threaded end portions a for the reception of the bearing-cones O C. The crank D in the construction shown is formed integral with Serial No. 689,573. (No model.)

the shaft. The end of the shaft opposite from the crank D is provided with a threaded bore 79. Adjacent to the cone 0 the shaft is milled on opposite sides, producing the parallel flat surfaces 0, which stand in a plane at right angles to the crank D.

Two quadrangular keys (I, having an outer beveled face 'e, are adapted to lie with their straight side against the milled faces a of theshaft and tobear against or rest upon the cone 0.

The sprocket-wheel E is provided with a bore f,- passing through the hub thereof, adapted to receive the shaft B, and with two opposed rectangular recessesg,leading from said bore, adaptedto embrace the keys d and having a beveled face e, the incline of which extendsin ward through the inner face of the hub of said wheel and is adapted to coincide with the beveled face of the keys (1. The sprocket-wheel is adapted to .be slipped over the end of the shaft, so that the recesses g in the hub thereof shall receive the keys (1, the inclined face e of the recesses in said sprocketwheel engaging the inclined face 6 of said keys, so as to wedge the sprocket-wheel tightly upon the shaft and prevent its turning thereon.

,F designates an annular washer, which is slipped over the outer end of the shaft 13 and bears against the outer face of the sprocketwheel.

same time forcing said keys against the cone 0, locking said cone upon the shaft by the same operation which looks the sprocket wheel and tightens the crank G. The stem of the crank G is screwed into the shaft until the shoulder a thereon bears forcibly against the washer F, when the boss h on said crank, in which is a threaded aperture, is brought to register with the screw h, which passes thron gh the arm 11 of the sprocket-wheel and is adapted to enter said boss, whereby said crank is securely locked from unscrewing.

To insure a proper alinement of the cranks, the recesses g are formed in the bore of the hub of the sprocket-wheel so as to register with the arm H of said wheel, through which the locking-screw h passes, so that the crank G when brought into position to receive the screw h will always stand in alinement with the crank D.

To enable the crank G to be always brought into proper position to receive the screw h, the cone 0 may be so adjusted on the threaded portion of the shaft as to allow the crank G when screwed tightly into place to stand in such position as to receive the screw h.

After the sprocket-wheel has been properly lock ed upon the shaft the bearing may be adjusted through the medium of the cone C, which is free to be adjusted after the crank G is locked and which after adjustment may be locked by the jam-nut C".

By means of the construction above set forth it will be seen that the sprocket-wheel, although firmly locked to the crank-shaft, is made readily removable therefrom bysimply unscrewing the crank G, when the washer F and the sprocket-wheel E may he slipped from the shaft, enabling an easy exchange of sprocket-wheels, if desired, or the ready removal of the crank-shaft from the hearing by simply unscrewing the cone O therefrom. \Vhen setting up the bearing, said parts may be quickly assembled and easily seen red in place, as before described.

Having thus fully set forth this invention, what is claimed is- 1. The combination of a crank-shaft of a bicycle, said shaft having a flattened face, a beveled key adapted to lie with its straight side against the flat face of said shaft, a sprocket-wheel apertu red to receive the shaft and having a recess which receives said beveled key, and a crank secured upon the projecting end of said shaft and bearing forcibly against the outer face of the sprocket-wheel.

2. The combination with the crank-shaft of a bicycle having a flattened face and a threaded bore in the end thereof, a cone threaded upon said shaft, a beveled key lying against the flat face of the shaft and bearing upon said cone, a sprocket-wheel apertured to receive the shaft and having a recess in which said beveled key is adapted to lie, a washer fitting on the outer end of the shaft and lying against the face of the sprocketwheel, a crank adapted'to be screwed into the threaded bore of the shaft and to bear forcibly against said washer,'and means for locking said crank.

In testimony whereof I sign this specification in the presence of two witnesses.

BURTON \V. SCOTT.

Witnesses:

E. WHEELER, M. A. MARTIN.

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