US597196A - Clarence l - Google Patents

Description

(No Model.)

U. L. GOODRIGH.

BICYCLE GRANK,

No, 597,196. Patented Jan. 11,1898.

Witnesses.-

By is vitto/'wey mf' M UNITED STATES PATENT Enron.

CLARENCE L. COODRICH, OF HARTFORD, CONNECTICUT, ASSIGNOR TO XVILLIAM W. TUCKER, OF SAME PLACE.`

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SPECIFICATION forming part of Letters Patent No. 597,196, dated January 11, 1898.

Application filed November 18,1895. Serial No. 569,264. (No model.)

To @ZZ wwm it may concern:

Be it known that 1, CLARENCE L. Go onRIcH, a citizen of the United States,residing at Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Bicycle-Cranks, of which the following is a specilication.

This invention relates to an improvement in detachable cranks for bicycles; and it comprises, in the preferred form thereof herein shown and described, crank arms or stems non-removably secured to the crank to which the pedals are attached and sleeved one upon the other. The stem of one crank-arm is of tapering form longitudinally and of different diameters throughout its length, the largest diameter being at a point adjacent to the collar of the crank on which the sprocket-wheel is placed. Sleeved upon this stem is a tubular body projecting from the other pedal-arm and having a tapering bore. This tubular body is externally provided with concaved recesses or depressions to receive the usual balls on which the bearing is fitted. The two crank-arms are preferably connected by a tapered key passed through openings in their ends and serving closely to draw the parts together when adjusted.

In the drawings accompanying and forming part oit' this specification, Figure 1 is a sidev elevation illustrating the bearing in place on the crank-arms and the usual sprocket-wheel in section. Fig. 2 is a longitudinal vertical section of my invention, illustrating the connected crank-arms in position within the bearing. Fig. 3 is a partial longitudinal section of the connected crank-arms. Fig. 4 is a detail view, partly in section, of the tubular crank-arm; and Fig. 5 is a detail side elevation of the solid crank-arm.

Similar characters represent like parts in all the iigures of the drawings.

The improved two-part crank-shaft herein described comprises an elongated tubular shaft having a tapering bore and externally fitted for support and rotation in suitable bearings, and having, rigid on one end thereof, a crank or arm for carrying the pedal and an elongated tapering shaft extending entirely through the central longitudinal bore of said tubular shaft, and having on lits projecting larger end a second and corresponding crank-arm, and means for detachably connecting said shafts together', preferably and as herein shown, at the crank end of the tubular shaft, so that the force of the crankarm of the central shaft is communicated through said attaching device directly to the crank-arm of the tubular shaft.

, The numeral 1 represents a preferably solid crank-arm, (shown non -removablyv secured to 'and projecting at right angles from the pedal support or crank 2,) although it may be separate from said crank and attached thereto in any well-known manner. This arm is provided with a shoulder or enlargement 3, on which the usual sprocket or driving Wheel 4 is mounted, with enlarged portions 5 and 6, respectively, of a tapering form or gradually decreasing in diameter toward the free end of the arm and with a reduced intermediate portion 7.

The numeral 8 represents a tubular crank arm or stem which is also preferably non-removably secured to the pedal crank or support 9. Tubular stem 8 is provided, adjacent to the end from which the `crank ll projects, 4with a circular concave recess or bearing 10, and at its opposite or free end With a circular rib or enlargement 11, having a concave wall or seat 12 for a purpose hereinafter described, said seat and Wall being preferably hardened in any well-known manner.

13 represents a tapered pin having a thread ed end iitted with a nut 1e, and 15 and 15 are holes in the respective arms or stems 7 and 8 for the reception of such pin. The hole 15 is made of greater diameter than the pin to permit the parts to slide or be adjusted one upon the other.

16 represents the bearing, which is to be mounted in the frame in the usual manner, said bearing being internally threaded at its ends 16 and 162 to receive externally-threaded rings 17 and 17', having inner annular concave seats or recesses 1S and 18', respectively.

19 represents antifriction-balls seated be tween the recesses 10 and 18 and concave wall 12 and recess 1S.

20 represents an internally-threaded ring which acts as a jam-nut to lock the ring 17' IOO either after it has been originally inserted or subsequently adjusted to take up Wear between the parts.

Both rings 17 and 17 are provided with recesses 21 and 21 to receive a Spanner-Wrench by which they may be inserted into the bearing or Withdrawn therefrom, and the rings 17 and 2O are each provided With a knurled or roughened peripheral portion to facilitate their manipulation by hand.

It Will be observed that the bear-ing is supported, adjacent to its extreme ends, on the balls or rollers mounted in the seats of tubular arm 8, and that by this means the strain caused by the. pedals is more equally sustained and there is less tendency of the shaft formed by the joined crank-arms to deflect or Wabble than in constructions where the balls and bearings are differently disposed.

In assembling the parts the balls, bearings, and rings are secured to the tubular arm 8, and the bearing is inserted in the frame. The arm 1, carrying the sprocket-Wheel, is then inserted in tubular arm 8, and the parts are rigidly secured together by the tapered pin 13. i

Owing to the tapering form of they bearingsurfaces 5 and 6 of arm 1 and the corresponding tapering bore of arm 8 the parts are readily adjusted on each other to take up Wear by simply tightening the tapered pin 13. By providing the reduced portion 7 intermediate the tapered portions 5 and 6 of arm 1 the tapered shaft 1 is capable of being inserted and Withdrawn more easily than if it were formed to have frictional contact throughout its length With the Walls of the bore of arm 8.

The crank-arms are readily disassembled by simply withdrawing the tapered pin 13 and then removing arm 1 from the tapered bore of arm 8.

Whilel have shown arm 1 as a solid arm, yet it is evident that it may be made hollow or tubular to save Weight, if desired.

It is obvious that my improved detachable crank above described is adapted for various uses, and the invention is therefore not limited in its application to a v'elocipede or bicycle. It is evident that the parts may be varied in construction from what is herein described, and that many substitutes for the tapering pin could be adopted as a means for uniting and adjusting the arms Without departing from my invention. It is also evident that the preferably-hardened seats for the balls could be formed in separate rings secured to the tubular crank-arm, instead of being made integral therewith, as described.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

1. The combination with a bearing-sleeve, of a two-part crank-shaft comprising an elongated tubular shaft extending through said sleeve having external bearing-surfaces and provided with a tapering bore extending longitudinally through the same, said tubular shaft having a crank-arm rigid on one end thereof; combined with a tapering shaft extending from end to end of said tubular shaft and having a crank-arm rigid on the projecting, larger end of said tapering shaft; and means for detachably connecting together said shafts at the crank end of one of the shafts, the construction being such that said connecting means will force one shaft into the other.

2. The combination of a bearing-sleeve; a tubular crank-shaft extending entirely through and rotatable therein and having a tapering bore extending longitudinally from end to end of said crank-shaft; and a cent-ral tapering crank-shaft extending entirely through said tubular shaft-bore from end to end thereof and detachably secured for rotation there- With.

3. The combination with a bearing-sleeve, of a two-part detachable crank-shaft comprising a tubular shaft extending through said sleeve having external bearing-surfaces and also having a tapering bore extending longitudinally through the Ashaft from end to end thereof; a central, tapering shaft extending through the tubular shaft; and a tapering pin extending through both of said shafts. for detachably Wedging said shafts together.

CLARENCE L. GOODRICH.

Vitnesses:

FRED. J. DOLE, HEATH SUTHERLAND.

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