US556852A - Frank h - Google Patents

Description

(NG Model.)

F. H.y LEFROY. GHANGBABLB GBARING.

No. 556,852. Patented Mar.. 24, 1896.

EJE

UNITED STATES PATENT FRANK I-I. LEFROY, OF NEV YORK, N. Y.

CHANGEABLE GEARING.

SPECIFICATION forming part of Letters Patent NoA 556,852, dated March 24, 1896. Application nea my 2, 1895. sain No. 554,746. or@ modem .To @ZZ whom t may concern:

Be it known that I, FRANK H. LEFROY, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Changeable Gearing; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to an improvement in gearing for crank-actuated vehicles, and it is embodied in the construction and arrange ment of members hereinafter .referred to and definitely pointed out in the claims.

The invention is designed more particularly for application to bicycles and tricycles, and is applicable to either the crank-shaft or the shaft of the driving-wheel.

Primarily the invention is designed to afford a very positive and easy variation of the leverage and consequently the speed of the driving-chain or other powentransmittin g instrumentality.

lVhile I have suggested that the invention is applicable to certain classes of vehicles, I wish it understood that it may be applied to other classes of machinery with equally as good results.

IIeretofore it has been suggested to vary the speed of the driving means or chain by shifting multiple gear of varying diameter, the gears being internal gears, and consequently limiting the number of variations to the interior diameter of the smallest gear, and in such constructions the multiple gears are of necessity loosely mounted eccentrically, and are susceptible of disarrangement by the warping or bending oi' their supports, thereby throwing their teeth out of true alignment with the moving pinion. These, as well as other objections, can be urged against structures employing internal multiple gears. It has also been suggested in numerous cases to employ a shifting-gear, which may be employed eccentricallyas well as concentrically, but which provides for but one change of speed. Such devices are, however, unsatisfactory, owing to the limit of variation and to the general complicated arrangement of parts. `With my invention these objections are practically overcome` In the drawings, wherein the preferred form of the invention is illustrated, and in which like letters of reference designate corresponding parts in the several views, Figure l is a longitudinal vertical section taken through the crank-shaft and sleeve of a bicycle. Fig. 2 is an elevation looking to the left hand of Fig. l and showing the shaft in section. Fig. 3 is a det-ail perspective of the shifting deviceA In the drawings, A designates the crank shaft, B the sleeve, and C the crank, all of usual construction, with the exception that the shaft A has alongitudinal spline l) thereon between the end of the sleeve and crank.

Slidingly supported on the shaft is the molto-gear D, the same being prevented from independent rotation by having a groove cut in its inn er wall into which the spline passes. This gear D is composed of a stepped series of disks d d d2, each having a diameter diftering from the other, arranged side by side and each being formed with external teeth, as shown. These gears constitute by preference an integral unit, but it is to be understood that they can be otherwise formed or constructedas, for instance, the several steps of the gear can be made separately and then bolted together. The inner wall of gear D is recessed and a circumferential groove d3 is formed in the edge wall of this recess, for purposes presently to be explained.

E designates the sprocket-wheel, which is vin the form of a ring having the sprocketteeth on its outer periphery and a series of gear-teeth on its inner peripheral wall. The diameter of the interior of the ring is substantially equal to the diameter of the part d of the gear, so that the latter will closely fit within the former, the teeth of the respective members intermeshing.

To independently support the sprocket-ring I form a groove in its inner side face and secure therein by a suitable locking-ring F the carrying-frame G, consisting preferably of a ring having a iiange fitting in the recess. Suitable balls maybe interposed, if desired, to form an antiriction-bearing for the sprocketring on the frame. The carrying-frame is iiXedly held from rotation by being supported IOO 'sleeve B.

on suitable arms g g' projecting outward from a sliding frame H and connected with the carrying-frame G at its bottom an d sides only, so that the upward movement of the-ring is unopposed by the arms.

The sliding frame II comprises the two curved side bars 7i ZL curved on a radiiwith its center the center of the rear axle to prevent the binding of the chain by the adjustments. These side bars are connected at their topsand bottoms by the web h2 and the crossbar '2.3.

K designates the supporting-plate keyedor otherwise flxedly secured on the end of the This plate is fashioned to conform to the shape of the frame H, but is somewhat smaller, its side edges being fitted in grooves h4 formed in a flange h5 on the side bars only of the frame H. By this means it will be apparent that the frame H will have or be permitted a substantially vertical movement on the supporting-plate or at about right angles to the shaft, and by its movement the sprocket* ring will be raised or lowered, as the case may be.

The flanges Zr" on the bars ZL Zt" project laterally beyond the cross-bar and web, so that the frame H is permitted a movement which kwill carry its opposite ends beyond the platel K, the limit of movement being governed by the distance between the cross-bar and web, which, as will be readily understood, can be greatly varied without necessitating structural changes in the machine-frame.

To effect the relative adjustment of the sprocket ring and gear I employ what I term an adjuster or cam L, which consists of a flat plate Z having a circular aperture therein,

and sleeve the same loosely on the hub Zo of the liXed plate K, the same being properly.

held in place by a suitable nut. The plate Z has an arm or actuating-lever L thereon, which extends upward to any convenient point and by which the same may be shifted or rotated about its axis. In the lower and side portions of the plate Z is formed a campath Z fashioned to correspond to the required vertieal movement of the sprocketring. Into this cam path or groove Z is extended a pin fm made fast to the web Zi of the plate I-I, so that as the plate Z is rotated the plate H will be raised or lowered through the medium of the pin, the pin working in a slot k3 in the plate K.

To provide for the movement of the gear D, I form a squared hollow bushing Zt' on the plate K, and through this bushing pass a link M squared in cross-section and having a hook o at its outer end which loosely engages in the groove Z3 of the gear D. The opposite end of the link is turned down or hooked, as at o', and passes into a cam-groove Z2 formed in a circular-shaped flange concentrically mounted or formed on the side of the plate Z of the adjuster L.

By reference to the drawings it will be noted kat right angles to the other.

one serves to elevate the pin therein the other.

being horizontal, will serve to move the link These cam1 grooves are so shaped that the movement or' the ,parts will be properly timed, and when needed the movement of the gear will be stopped and both movements interrupted or locked by interrupted pitches in the cams.

It will be noted that the shifting device and the supporting-frame H are both arranged inwardly beyond the gear and are therefore located in a position to prevent accidental interference, and at the same time may be readily applied to the usual structure vwithout materially altering the parts.

In operation, by shifting the lever L' the gear is moved longitudinally, and as its sue ceeding step reaches the plane of the sprocket-rin g the latter is lowered onto the gear and the speed thereby varied, the movement be- .ing simple and eective. By forming the bushing on the plate K the link M is held in its horizontal position, so that it is prevented from being cramped orbound in the groove (Z3.

"While I have shown what I deem the preferable form of construction I wish it understood that other forms may be employed so long as the principle of the external gear is retained, which feature I regard as of much importance. I have shown but a three-stepped gear for convenience, but it will be evident that any desired number may beused, ranging from two to ten or twenty. The gear being supported directly on the axle is held positively irrespective of weight or number.

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

l. In a gearing for crank actuated machines, the combination with a crank-shaft and a sleeve, of an externally-toothed muitogear loosely mounted on the shaft and comprisinga series of gears of varying diameters. means for preventing an independent rotary movement of the gear, a vertically-adj ustable power-transmitter ring having a toothed inner wall, an adjustable frame supporting the ring, a fixed support with which the frame slidingly engages, and shifting means for changing the relative position of the gear and sprocket, substantially as described.

2. In a changeable gear for crank-actuated machines, the combination with a shaft, of a stepped multe-gear sleeved directly on the shaft and formed with external teeth, means for preventing an independent rotation of the shaft and gear, a power-transmitting ring with which the gear engages, means for shift` ing the ring at substantiallya right angle to the gear, and means for changing the relative lateral position between the gear and ring, substantially as described.

3. In a changeable gear for crank-actuated machines, the combination with a crank-shaft and its sleeve, of a longitudinally-movable IIO muito-gear sleeved on the shaft having` eX- ternal teeth, means for preventing independent rotation oi' the gear and shaft, a plate fixed on the sleeve, a curved carrying-frame slidinglysupported on the plate, arms on the frame, a power-transmitting ring arranged to engage with the gear, loose connection between the ring and arms, a shifting cam mounted on the sleeve having a plurality of cam-paths therein, a sliding connection between the cam and carrying-frame, and a sliding connection between the cams and gear, substantially as described.

et. In a changeable gear for crank-actuated machines, the combination with a crank-shaft and its sleeve, of an externally-toothed muitogear on the shaft, a power-transmitting ring arranged to engage the gear, a curved carrying-frame for the ring comprising two side bars, and laterally extending supportingarms, a plate xed to the sleeve and with which the frame sli din gly engages, and a shifting device mounted on the sleeve inwardly beyond the plate for changing the relative position of the ring and gear, substantially as described.

In a changeable gear for crank-actuated machines, the combination With a crank-shaft and its sleeve, of an externally-toothed multogear, slidingly supported on the shaft, means for preventing independent rotation of the gear and shaft, a sprocket-ring independent of the gear, having internal teeth arranged to engage the gear, a carrying-frame located inwardly beyond the gear, arms extending outward from the frame and having a journal connection with the ring, a xed support for the frame with Which the latter has a sliding connection, and a shifting device having connections With the frame and gear and loosely sleeved on the frame, substantially as described.

G. In a chan gea-blc gear for crank-actuated machines, the combination with a crank-shaft and its sleeve, of a multe-gear on the shaft, a power-transmitting ring arranged to engage the gea1,means for adjustably supporting the ring directly on the sleeve, a rotatable shiftingl device having horizontal and verticalcam-grooves therein and connections engaging in the grooves for changing the relative positions of the gear and ring, substantially as described.

7. In a changeable gear for crank-actuated machines, the combination with a shaft, of a muito-gear on the shaft, a sprocket-ring independent of the gear, a ring supporting the sprocket-ring loosely engaging therewith, a curved carrying-frame for the supportingring located inward from the ring, arms connecting the carrying-frame and supportingring, a fixed support for the carrying-frame a cam-plate having loose connection with the carrying-frame and gear, and comprising a horizontal plate and a vertical plate having cams thereon, and a lever for shifting the plates, and means operated by the cams for shifting the gears and ring, substantially as described.

8. In a changeable gear for crank-actuated machines, the combination With a shaft, of an external toothed multe-gear loosely mounted to move longitudinally on the shaft, a poiver-transmiting ring arranged to be engaged With the gear and movable in a vertical plane only, and means Jfor changing the relative position of the ring and gear, so that the ring will be caused to engage the dierent steps or sections of the gear, substantially as described.

In testimony whereof I aiiix my signature in presence of two Witnesses.

FRANK II. LEFROY.

Witnesses G. A. PENNINGTON, L. S. BACON.

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