US821597A - Variable-speed mechanism. - Google Patents

Description

No. 821,597. PATENTBD MAY 22, 1906.

G. F. POUGHER.

VARIABLE SPEED MEGHANISM.

APPLICATION FILED 00T. 6, 1905.

2 SHEETS-SHEBT 1.

No. 821,597; PATENTED MAY 22, 1906.

C. F. POUGHBR.

VARIABLE SPEED MEGHANISM.

APPLICATION FILED OCT.6. 1905.

2 SHEETS-SHEET 2.

Uivrrnn erariale OFFBOB.

CHARLES FORRYN POUGHER, OF BIRMINGHAM, ENGLAND, ASSIGNOR TO .THE BIRMINGHAM SMALL ARMS COMPANY LIMITED, OF BIRMINGHAM,

ENGLAND.

Specification of Letters Patent.

Patented May Q2, 1906-.

Application ileo October 6, 1905. Serial No. 281,621.

To tI/Z when@ 'llt may concern:

Be it known that I, CHARLES FORRYN POUGHER, a subject of the King of Great Britain, residing at 36 St. Oswalds road, Small Heath, Birmingham, England, have invented certain new and useful Improvements in Variable-Speed Mechanism, of which the following is a specification.

This invention has relation to variablespeed driving mechanism for cycles and motor-cycles, 'motor-cars, and other mechanically-propelled vehicles, but has more particular reference to two-speed driving-gears for bicycles.

One ofthe objects of the present invention is to provide an improved construction of epicyclic two-speed gear which can be so dcsigned as to afford a lower percentage of difference between the two speeds than is possible with the sun-and-pla'net gears above referred to, while another object is to simplify the construction of such mechanism and render same perfectly reliable when in use, in addition to facilitating the operation of changing. speeds and reducing to a minimum the friction between the running parts when the drive is being transmitted through the gears.

Figure I of the accompanying drawings represents a section, with parts in elevation, of a two-speed cycle-hub constructed and arranged in accordance with my invention. This view shows the several parts in the lowspeed positions-that is to say, the controlling-cam is positively locked or held stationary and serves as a bearing around which the eccentric-pinion rotates in transmitting the drive to the internal tooth-ring and hubshell at a reduced speed relative to the external chain-wheel. Fig. 2 is a similar view, but portions of the eccentric driving-pinion are broken away, so as to show part of the controlling-eccentric in elevation, and the various elements are shown in the high-speed positions in which the controlling-eccentric is freed from its locking device and is coupled to the eccentric-pinion so that the said eccentric and pinion are free to revolve bodily around the spindle and carry the internal toothed wheel and the hub-shell with them at the saine speed as the external chainwheel. Fig. 3 is a transverse vertical section of the hub taken upon the dotted line Fig. l,

and looking toward the right-hand end of the hub, so as to show the relative dispositions of the controlling-eccentric, the driving-pinion, the internal toothed ring, and the hub-shell. Fig. 4 is a transverse section taken upon the dotted line Fig. l, showing the arrangement of the means provided for transmitting the drive from the external chain-wheel to the eccentric-pinion. Fig. 5 is a similar view; but the section is taken upon the dotted line Fig. 2, and the parts of the drive-transmission mechanism are shown in a different position. Fig. 6 represents a separate plan of the controlling mechanism by 'which the change of speed is effected and shows the relative dispositions of the controlling-eccentric, the clutch devices, and the screw-actuated slide, whereby the said eccentric is shifted laterally and engaged either with the pinion or with the stationary element of the clutch system. Fig. 7 shows the same parts in side elevation; and Fig. 8 is a longitudinal section thereof, showing the manner in which the stationary element of the clutch system is made a fixture relative to the frame of the machine when the hub is in position. Fig. 9 is a detail front elevation of the slide. Fig. 10 is a detail front elevation of the rotatable nut.

The same letters of reference indicate corresponding parts in the several figures of the drawings.

In the arrangement represented in the said figures the hub-shell c is freely mounted upon two sets of ball-bearings e c2, of which the iirst-named are arranged at the right-hand end between a cup or bearing-ring a, screwed into the shell, and a cone a", formed on the inner face of the outer portion b/ of a drivingsleeve Z), which surrounds a stationary and solid axle c and has screwed or otherwise applied to the said external part of it either a fixed chain ring or free wheel-clutch d of the usual construction, which provides an automatic action on both speeds, while the ballbearings e2 at the left-hand end of the shell are disposed between a second cup or ring et", screwed into this end of the said shell, and a stationary cone e, which is formed with a clearance for the actuating-slidef of the controlling mechanism to work within and is provided on its outer side with a slotted IOO sleeve or barrel e, serving as the bearing for a rotatable nut g, whereby the said actuatingslide is traversed in one direction or the other, as hereinafter described. T he solid axle c is secured to the frame in the usual way, and the'driving-sleeve may be mounted on ballbearings b2, disposed between a cup b3, formed in its outer end, and a cone b" on the said axle.

The internal gear-ring or toothed annulus h, constituting the driven member of the epicyclic gear, is iixed in about the middle of the hub-shell and prevented from rotating therein, preferably by key ribs or feathers 7i on its outer periphery engaging within internal grooves h2 in the shell and being there retained by any suitable locking arrangement. In the particular form shown the right-'hand end of the ring is provided with a circumferential flange or collar h3, adapted to bear against internal shoulders i in the hubshcll, and it is kept up to its bearing by a distance-ring i, which is interposed between the flanged end of the said gear-ring and the cup a3, so that bythe screwing home of the said cup the gear-ring is rigidly secured to the shell, but in such a manner that it can be readily disassembled therefrom when necessary.

On about the middle part of the axle is loosely mounted the eccentric-block or controlling element j, and this block is concentrically surrounded in turn by the loose driving-pinion 7c, which is located eccentrically within and gears with the fixed internal gearring. The relative sizes of the driving-,pinion and the gear-ring depend upon the ratios ofthe two speeds required or the percentage of reduction that is to be provided for.

In order to transmit motion from the driving-sleeve to the eccentric-pinion, any suitable stud and slot or equivalent mechanism may be used, but preferably the systeml represented in the drawings is adopted, in which the inner end of the driving-sleeve b is formed with a cross groove or channel m, which is engaged by a pair of feathers vm on the adjacent'face of a loose intermediate plate m2, interposed between the driving-sleeve and the eccentric-pinion and having a central clearance m3 of larger diameter than the axle, while its inner side carries another pair of feathers m", disposed at right angles to the irst named and engaging with corresponding channels or grooves m5, cut transversely in the opposed end of an extension of the pinion. This interposed drive-plate forms a floating connection or coupling between the sleeve andthe pinion and is free to slide or change its position with respect to the two other elements, while it is nevertheless ccmpelled to rotate bodily with both of them in transmitting rotatory movement from the concentric element to the eccentric one.

To hold the parts of thc drive-transmission mechanism together, it is proposed to make the feathers and the grooves or channels with which they engage of a T-shaped dovetail or hook-like section so that they cannot be separated laterally, but are nevertheless capable of the relative sliding movement above described. In the arrangement represented in the drawings the T formation is adopted,

For the purpose of locking the controllingeccentric either to a stationary member connected with the frame of the machine for the low-speed drive or to the pinion for the highspeed drive the said eccentric is arranged so as to be capable of a sliding motion upon the axle and within the hub of the said pinion and has combined with it a double-action clutch device having at its opposite ends ratchetshaped or other teeth adapted to engage, respectively, either with corresponding teeth formed on the left-hand side of the pinion or with the teeth of a locking-collar, which is anchored in such a manner as to be afixture relative to the frame of the machine, as hereinafter described. Thus the left-hand end of the pinion is formed with a concentric set of ratchetlike teeth, and the left-hand end of the sliding eccentric-block carries a collar or clutchring f/t, having teeth n2 corresponding to and opposed tothose, n, on the pinion, and these teeth n n2 are adapted to be engaged and disengaged by the sliding of the block to and fro upon the axle. Further, the said block has also formed upon its left-hand end a short sleeve or extension n3, which is concentric with respect to the axle and has on its outer face a ring of ratchet-like clutch-teeth n4, while secured in a stationary position relative to the frame of the machine is a locking collar or ring o, whose inner side has similar teeth 0, with which the teeth of the sleeve are engaged when the eccentric-block is drawn outward by the clutch-actuating mechanism.

To facilitate the meshing or striking of the teeth n n2 when the sliding eccentric is moved toward the right-hand end 0f the hub t0 engage with the pinion and obtain the highspeed drive, the clutch-ring n is preferably mounted in such a manner as to be capable of a limited rotatory movement upon the said eccentric, although it is iirml'y secured thereto in a lateral direction. This is effected by making the ring separate from the eccentric and providing its left-hand end with a series of ears or tongues as, having ggooves a5, while the eccentric itself carries a ed collar ab' with gaps a7 formed therein, these gaps being of a greater width than the tongues, so that the latter may have free play within the former to an extent equal to the movement which the clutch-ring is to have around the eccentric. l/Vhen the parts are assembled, the plain edge of the clutch-ring fits against the 'inside vof the fixed collar n, and the grooved parts of the tongues extend beyond the left-hand edge of the said collar, so as to admit of the two parts being secured TUO iro

Ysiente? together' laterally (but without interfering with their relative angular movement) by springing` a locking-wire p into the grooves n, as shown in Figs. l and 2.

For traversing the combined eccentricblock and clutch to and fro upon the axle a clutch-actuating device is employed, consisting of a forked slidef, having at its inner end an internal fiange f2, which engages with a circular groove f3 in the sleeve extension n3 of the eccentric-block, and thus establishes a swiveling connection between these parts, which admits of the said block freely rotating around the axle, but compels it to move with the slide on the latter being traversed or moved backward and forward for changing the gear. The flanged end of the said slide is also formed into a cradle j" into which the tooth part of the sleeve extension n3 extends, and is presented to the toothed face of the locking-ring o, as hereinafter described.

To prevent the slide from rotating or twisting upon the axle and also to guide same in its sliding movement, its opposite sides or branches f 4, which embrace the said axle, extend outwardly through clearances in the bearing-cone e into a pair of guide-slots e3, formed in the barrel e, and as this cone is a fixture to the hub when the hub is assembled in a machine it follows that the slide confined within it is also effectually held against rotatory movement. The barrel of the cone and the branches of the slide project beyond the end of the hub, and the former constitutes a bearing or support for the nut g ofthe gearchanging mechanism, whose female screwthread g engages with male screw-threadsj', cut upon the outer edges of the branches of the slide extending through the slots e3. The nut itself is mounted in a box or bearing q, made fast to the axle by any suitable means, and is preferably rotated by a sliding rack r, engaging with aring of teeth g2, cut around its outer periphery, although it is to be understood that any other suitable arrangement may be provided for rotating the nut or traver sing the clutch-actuating slide.

The stationary locking-ring o, with which the controlling-eccentric is engaged when the drive is to be transmitted at the reduced speed, is carried within the cradle at the inner end of the non-rotatable slide f, into which it is dropped or inserted prior to the said slide being passed over the axle in assembling the parts, and the said ring is prevented from rotating (other than to a limited extent sufficient to facilitate the meshing of its teeth with the teeth n4 ofthe eccentric) by means of a pair of stops or shoulders 02, which overhang the branches of the slide, but do not interfere with the movements of the latter upon the axle. The locking-ring itself is prevented from sliding upon the axle by confining same between a shoulder s on the latter and a coiled spring t, which is interposed between the said ring and suitable abutments f inside the slide. This spring is also used for the purpose of moving the slide outward and automatically locking the eccentric and throwing the low gear into operation on the release of the rack r, which is connected with a system 'of gear-changing rods and levers or with an operating-cable or the like. It is, however, obvious that the locking-ring may be confined to the axle or prevented from sliding thereon by a split wire, which is sprung into a groove in the axle, or in any other manner which will not interfere with the movements of the slide.

When the parts of the hub are placed in the position represented in Fig. i by the outward movement of the clutch-actuating slide, the eccentric y' is locked or held stationary upon the axle by the engagement of the teeth n* with the locking-collar o, and thusforms a rigid bearing around which the pinion rotates when motion is transmitted to it from the externalv chain-wheel and the sleeve b through the fioating intermediate drive-plate m3, and this motion will be transmitted from the pinion to the internal gear-ring and hubshell at a less speed than that at which the external chain-wheel is rotated, this reduction in speed being of course proportional to the tooth ratios of the intergearing elements; but assuming that it is desired to change onto the high speed the gear-changing lever is operated by the rider, so as to draw forward the rack r and rotate the nut g in a direction which will force the clutch-actuating slide inward and carry the clutch and the eccentric-block with it. This movement will first disengage the clutch-teeth n4 from the collar, so that the eccentric is freed or released from the axle, and then take the teeth n2 of the said clutch into engagement with the ratchet-teeth n on the opposed side of the eccentric-pinion, which has the effect of locking the said pinion and the eccentric-block solidly together, while at the same time the pinion is rendered incapable of relative movement within the internal-toothed ring, .so that when the motion is transmitted through the intermediate drive-plate the whole of the parts revolve bodily or solidly around the axle at the same speed as that at which the said chain-wheel is driven. Vhen the drive is transmitted in this way, the intermediate mi makes no sliding or floating movement with respect to the sleeve b and the pinion, but simply rotates bodily with them around the axle as a center.

The application of the invention to speedgears arranged in connection with the crankaxle bracket of a bicycle or in connection with the driven shaft of a mechanically-propelled vehicle differs in no essential respect from its application to a bicycle-hub gear, as herein described.

Having fully described my invention, what IOO ITO

I desire to claim and secure by Letters Patent isl. In a variable-speed mechanism, a controlling-eccentric, a driving-pinion loosely mounted upon the same, a looking element, and a sliding toothed clutch device for positively connecting the said eccentric either to the driving-pinion or to said stationary locking element.

2. In a variable-speed mechanism, a controlling-eccentric, a driving-pinion loosely mounted upon the controlling-eccentric, a locking element, a sliding clutch device having tWo sets of teeth adapted When actuated to engage respectively With corresponding teeth on the driving-pinion and on the locking element, the latter being fixed to the frame of a machine and whereby when the clutch is in one position, the said eccentric is positively connected to the pinion to provide for transmission of the drive of the high speed, and when in another position the eccentric is positively engaged With the locking device and constitutes a bearing around Which the free or loose pinion revolves When transmitting the drive at the reduced speed.

3. In a mechanism of the class described, a controlling eccentric, a driving pinion loosely mounted upon the controlling-eccentric and having teeth, a clutch device movable upon a fixed axle and provided at one portion thereof with a series of teeth adapted to engage with the corresponding teeth on the driving-pinion, and it basking-ring fixed to the frame and adapted' for engagement with the clutch device.

4. In a mechanism of the cl-/Lss described, a driving-pinion, a controlling-eccentric supporting said pinion, and a fixed internallytoothed driving element, a locking element, a sliding toothed clutch device adapted to positively connect the said eccentric either to the driving-pinion or to the locking element, and means for actuating the clutch device.

5. ln a mechanism of the class described, a controllingeccentric, a driving-pinion loosely mounted thereon, a stationary locking ring, a sliding toothed clutch device adapted to positively connect the eccentric either to the driving-pinion or said lockingring, and an externally-operative clutch-actuating slide connected With said clutch device ior operating the same.

In testimony Whereot1 l have hereunto set my hand in presence of tWo subscribing Witnesses.

CHARLES FORRYNk POUGHER.

Witnesses:

HENRY SKERRETT, HENRY NORTON SKRRRETT.

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