CH369976A - Gear change device by chain derailment, with articulated parallelogram, for cycle and similar vehicle - Google Patents

Description

Gear change device by chain derailment, with articulated parallelogram, for cycle and similar vehicle The object of the present patent is a gear change device by chain derailment, with articulated parallelogram, for cycle and similar vehicle. We already know of such devices in which means resting on the chain and entering it transversely to move it on the sprockets, are carried by an articulated parallelogram fixed to the frame of the vehicle, generally close to the axle. of the rear wheel.

The device according to the invention is characterized in that it comprises a support bracket intended to be fixed to the frame of the cycle, an articulated para1161ogram in the form of two Supports, each in the form of a double yoke, and two lateral levers approximately parallels pivoted between the pairs of wings of the yokes of the said supports located opposite one another, the upper support being pivoted on the support leg and biased by a spring intended to cause it to rotate relative to this yoke, while that the lower Support carries a chain-guide device pivoted on it and which is also biased by a spring tending to make it rotate relative to this Support, the transverse displacements of the chain-guide device resulting from the deformation of the para116- logram being controlled , in one direction, by a flexible traction member, the end of which is attached to a catch integral with the side lever of the parallelogram located on the outside and, in the other direction, by a return spring bearing against one of said lateral levers, and in that it comprises stop means arranged so as to limit the pivoting of the upper support with respect to the support leg and the first pivoting of the chain guide device with respect to the lower Support under the action of their respective springs and stop means arranged so as to limit the deformations of the parallelogram in both directions, these stop means being manually adjustable.

The appended drawing represents, by way of example, one form of execution of the gear-changing device which is the subject of the invention and variants.

Figs. 1 and 2 are respectively front and side views of this form of execution.

Figs. 3 and 4 are sections of this device, in two different positions and on a larger scale.

fig. 5 is a section along line 5-5 of FIG. 3.

fig. 6 is a side view of the device according to arrows 6-6 of laRTI ID="0001.0269"WI="5" HE="4" LX="1437" LY="1723"> fig. 1.

fig. 7 is a view along the arrows 7-7 of FIG. 6.

fig. 8 is a partial view of a first variant, on a larger scale, FIG. 9 being a view along the arrows 9-9 of FIG. B.

fig. 10 is a partial view of a second variant, on a larger scale, FIG. 11 6tant a view according to the arrows 1l-11 of fig. 10.

fig. 12 is a partial view of a third variant, on a larger scale, FIG. 13 being a section along line 6-6 of FIG. 12.

Figs. 14 and 15 are partial views: of another variant, respectively in profile and from the front. fig. 16 is a perspective view of an element of this latter variant.

The illustrated gear-changing device comprises a support bracket 1 of known type, having an open slot 1i and intended to be engaged in an adjustable manner on the axis a of the rear hub of a cycle carrying stepped sprockets, I>p,</I> p1 and p2. A bolt-nut assembly 2 locks the support leg 1 against a door of the frame of the cycle. The speed change device further comprises an upper support 3 pivotally mounted on an extension of the bracket 1, and a lower support 4 carrying a chain guide assembly.

The two Supports 3 and 4 are identical, to simplify manufacture, and they are made economically in sheet metal cut and bent in the form of two opposite yokes with the wings respectively 31 and 32, on the one hand, and 41 and 42 , on the other hand. The pairs of wings 32 and 42 of the two yokes face each other and each carry two pa ralleles articulation axes 33 and 43 On which are pivoted freely, between said wings, two levers 5 and 6, having a flat or profiled shape and which are terminated by bosses 51, 61 crossed by axes 33 and 43.

The, levers 5 and 6 have equal lengths while the axes 33 on the one hand, and the axes 43 on the other hand, have same spacing, so that these bodies constitute an articulated parallelogram. Lever 5 is considered the outer lever, while lever 6, closer to the chain and sprockets, is considered the inner lever.

The wings 31 of the upper support 3 are used for the pivoting mounting of said support on the leg 1. The pivot axis is constituted by a bolt 7, (fig. 3) whose smooth rod freely passes through the wings 31. A threaded end 71 of the bolt 7 has a smaller diameter and passes through a washer 8 as well as bracket 1. A nut 9 locks bolt 7, washer 8 and bracket 1 together.

A spring 10 is engaged around the smooth surface of the bolt 7. One end 101 of this spring is engaged in a hole drilled in a wing 31 of the Support 3. The other end 102 of the spring is engaged in a longitudinal slot 72 of the bolt 7. A sleeve 11 (plastic, rubber metal or other material) protects the spring 10.

The washer 8 is rotationally integral with the bolt 7 whose bearing surface 71 has two flats <B>733</B> cooperating with flats of the opening of the washer (fig. 5). On the other hand, the washer 8 has diametrically opposed tabs folded in opposite directions 81, 82 and a circular tension is given to the spring 10 in a direction tending to cause the Support 3 and the members associated with it to pivot in the 1st direction. hands of a watch, to tighten the chain. The leg 81 of the washer 8 bears permanently against the support leg 1. The leg 82 constitutes a stop On the trajectory of the Support 3, limiting the rearward pivoting of the Parallelogram, which facilitates the wheel removals.

In a comparable manner, the wings 41 of the clevis of the lower Support 4 carry a shaft 12, a shoulder 121 of which abuts against one of the wings 41, with free pivoting. however prevent the relative angular displacement of these elements. A spring 14 is engaged around Faxe 12 between wings 41. One end 141 of this spring is engaged in a hole drilled in a flange 41. The other end 142 of the spring is engaged in a longitudinal slot 122 of Faxe 12 and the first spring and protected by a protection sleeve 15.

Ort thus obtains a support device comprising two points of articulation constituted respectively by the bolt 7 and by the bolt 12, and which are each stressed by a spring tending to elastically maintain this device in a determined angular position.

This double-jointed device operates in the following way when the chain requires it (by changing the freewheel sprocket), a set of flanges 16 and 17 carrying chain guide rollers 18 and 19 tilts towards the rear or towards 1 forward by pivoting On the lower joint 12. If there is excess chain tension, this is automatically corrected by the inclination of the oscillating Parallelogram On the upper joint 7.

This feature is very interesting, since it makes it possible to absorb the great chain wobbles observed when there are large gaps in the teeth, and also because it ensures greater winding flexibility. This flexibility makes it possible to eliminate unexpected irregularities, such as a hard link, gravel on the chain, etc...

The other end of Faxe 12 is integral with the flange 16 bearing in cooperation with a counter-flange 17, axes 181 and 191 of two chain guide rollers 18 and 19 mounted in free rotation, the flanges, counter-flanges, axes and rollers constitute the chain guide device itself. A characteristic of this chain guide device lies in the distance or eccentricity with respect to the axis 12 of the fictitious line joining the axes of the rollers 18 and 19. This eccentricity has the effect of lowering, with respect to the pinions p, p1, p2, the Position of the roller 18 says upper roller, which allows the chain to pass more easily On the first sprocket of large diameter p2. This arrangement increases the capacity of the device by allowing the use of a pinion p<B>2</B> of larger diameter.

The circular tension given to the spring 14 tends to drive in rotation RTI ID="0002.0546" WI="3" HE="4" LX="1558" LY="2126"> the first chain guide device (in the first clockwise direction dune watch) which tightens the chain. A rod 161 integral with the flange 16 and capable of abutting against the first Support 4, however, limits the first pivoting of the chain guide device towards the front. This limitation facilitates disassembly and reassembly of the wheel.

The deformations of the articulated Parallelogram, that is to say the pivoting of the levers 5 and 6 with the corresponding transverse displacements of the chain guide device, are controlled, in the direction of displacement towards, the large pinion p2, by a guide cable 20 and protected by a sheath 21, (fig. 6). The sheath 21 rests in a stop in the sheath 22 extending Faxe<B>32,</B> of the interior lever 6. The end of the cable is fixed On a fastening lug 51 of the lever 5. hand that the position of the tab 51 is closer to the axis 43 than to the Y axis of the lever 5, and on the other hand, that the tab 51 extends up to the proximity of the interior lever 6. The pivot arm with respect to the axis 33 of the lever 5 is therefore as large as possible, which facilitates the pivoting of the lever 5 and gives great smoothness of operation.

In the other direction, the transverse displacements are controlled by a spring 23 which is mounted on an axis 24 secured to a wing 32 of the Support 3. A strand 231 of the spring is fixed to the Support 3 (fig. 3). The other strand 232, extended downwards, bears against the inner face of lever 5. This strand 23<B>2</B> is housed in the hollow of the concave profile of lever 5 and is held between tab 51 and a paw 52.

The lug 52, formed by a folded part of the lever 5, extends to the vicinity of a threaded rod 29, the ends of which are fixed in heads 25 integral with the external lever 5. Two knurled nuts 26 and 27 are screwed onto the rod 24 , on either side of the lug 52 and the springs. 28 mounted in compression between the nuts and the heads 25, serve to slow the rotation of said nuts and to maintain them in their adjustment positions.

The adjustment device, simple and entirely manual, constituted by the nuts 26 and 27 placed on the trajectory of the bracket 5<B>2</B> makes it possible to limit with precision and without any friction, in both directions, the 1st movement transverse of the chain guide device. Figs. 3 and 4 illustrate these extreme positions, corresponding to the positions of the chain C On the first pinion p and On the first pinion p-' and which Fon can adjust conveniently, with precision, by means of the very accessible knurled nuts 26 and 27.

Figs. 8 to 12 represent variants of the articulation of the upper support 3 on the support leg 1. The articulation of the lower support 4 with respect to the axis of the chain guide device can be arranged in the same way.

In a first variant represented in FIGS. 8 and 9, the upper support 3 in the form of a double clevis comprises two wings 34 and 35 serving for mounting on the hinge plate and two wings 31 and 37 carrying the levers 5 and 6 constitute the first paral2ogram.

The wing 31 has a conical opening 33 in which is housed a corresponding conical port 301 of a hinge pin 30. On the side of its attachment to the support bracket 1, the wing 30 has a threaded port 302 , with flats 303 for angular positioning. At the other end, pin 30 has a threaded seat 304 intended to cooperate with a mobile cone 31. easily accessible exterior of the gear change device. The mobile cone 31 has notches 311 facilitating adjustment manipulations.

Following the cone 31 is engaged on the bearing 304, in a non-screwed manner, a washer 32 however having a flat surface projecting in its bore which positions it angularly On a corresponding flat 305 of the bearing surface 304.

A lock nut 33 screwed last on the port6e 304 blocks the first cone 31 in the adopted adjustment position. The effect of the counter nut 33 on the cone 31 is exerted through the intermediary of the washer 32 in a constant angular position, which prevents the cone 31 from being adjusted by locking the counter nut 33.

The outer end 306 of the axis 30 can be arranged in any useful or decorative manner (decorative patterns, concave imprint, paint, cabochon, etc.). A circular housing 332 of the lock nut 33, Jans which is partially embedded in the washer 32, makes it possible to reduce the projection beyond the support 3.

The articulation also comprises the first return spring 10 hooked on the one hand, at 101 On the first bottom of the Support 3 and, on the other hand, at 102 in a slot 307 milled in Faxe 30. A sleeve 34 protects the articulation.

In a variant illustrated in FIGS. 10 and 11, the articulation axis is supported by a mobile cone 35 screwed onto the threaded seat 304. This cone 35 has a flange 351 comprising driving flats and a screw 36, screwed into the extremity of the axis 30 and having a hexagonal head 361, ensures the first blocking of the cone 35. A chamber hollowed out in the end of the cone 35 and intended for the head of the screw 36 would make it possible to reduce the size.

In a variant illustrated in FIGS. 12 and 13, a hinge pin 38 is carried by a mobile cone 37 screwed on a threaded port 381 of the axis 38. slotted diametrically as shown at 382 (Fig. 13), so that screwing in screw 39 causes gate 381 to expand radially and cone 37 to lock. attaches to one end of spring 10.

The variant represented in FIGS. 14, 15 and 16 relates more particularly to the execution and assembly of the spring which acts as a return on the levers of the articulated para1161ogramme, and also to the production of the device for adjusting the transverse displacements of the chain guide assembly. We wanted to make the return spring more robust and more powerful, by operating its assembly in a more rational way.

In this variant, the levers of the articulated parallelogram remain designated by 5 and 6.

The device comprises an upper support 40 having upper wings 401 and wings. lower holes 402 and 403 pierced, the first, with a smooth hole 404, and the second, with a tapped hole 405 serving for the removable fixing of a pin 41. The pin 41 is screwed until it abuts against the inner face of the wing 40s and a return spring 42 is mounted on said axis, between the wings 402 and 403. This spring comprises contiguous cylindrical coils constituting the first spring itself, and it is divided into two equal parts, of different winding directions, joined by lower strands of link 421 terminated by a ball 422 shaped to bear against the inner face of lever 5 of the parallelogram. End strands 42s and 42s of the spring run parallel, as shown in FIG. 16, in a position of rest at 90 with respect to the branch 421. These strands 423 and 421 are housed in holes drilled in the bottom of the upper Support, and the spring is strapped so as to exert an elastic thrust against the lever 5.

This construction has the advantages - of eliminating any overhang in the axis of the support of the return spring. Spring 42 is firmly guided and spring 41 is supported at both ends by wings 402 and 40s. The large number of coils of the spring 42 also contributes to improving the guiding of the spring.

- to improve the balance of the spring 42 (shape and symmetrical attachments). The high number of turns also makes it possible to obtain greater smoothness in the operation of the mechanism.

- to increase safety because the upper sections and the lower section of the spring, which constitute weak points, are doubled. Alternatively, for reasons of economy in particular, the spring 42 could be replaced by two separate symmetrical springs.

Studs 43 and 44 sohdaires of the lever 6, sollt relatively close together and carry a threaded rod 45, of reduced length On which sollt screwed knurled adjustment nuts 46 and 47 dopt the first braking is provided by a single spring, or compression 48.

Deerit gear-changing devices are simple and economical in construction and have many advantages - possibility of very precise and rapid manual adjustment, without the aid of any tool, of the amplitude of the transverse movement of the chain guide device .

- possibility of immobilizing the first chain guide device On one of the sprockets of the freewheel (for example the first middle pinion p1) in the event of an operating incident such as the breakage of the cable 20, by quickly adjusting the nuts 26 and 27 which will then come into abutment against the gatte 52, on the other side thereof.

- simple and effective stops for positioning Supports 3 and 4.

- eccentricity towards the bottom of the attachment point of the chain guide device.

- economical execution, by cutting and folding, of different organs.

- protection of the springs surrounding the axes of the Supports. - rational attachment of the cable to the external lever of the parallelogram, giving great smoothness of operation.

- convenient backlash and precise adjustment of the upper and lower joints.

Finally, in a variant not shown, a cover may still be provided which is integral with one of the supports or with the external lever and which is arranged to protect the adjustment device and the first spring housed between the levers 5 and 6 of the parallelogram; this cover can in particular be pivoted to give access to the manually adjustable knurled nuts.

Claims (14)

CLAIM Device for changing gears by chain derailment, with an articulated parallelogram, for a cycle and similar vehicle, characterized in that it comprises a support bracket intended to be fixed to the frame of the cycle, an articulated parallelogram in the form of two supports, each in the form of a double clevis, and of two approximately parallel side levers pivoted between the pairs of wings of the clevises of the said Supports located opposite one another, the upper Support being pivoted on the support leg and urged by a spring intended to make it rotate with respect to this catch, while the inner support carries a chain-guide device pivoted on it and which is also urged by a spring tending to make it rotate with respect to this Support, the transverse displacements of the chain guide device resulting from the deformation of the parallelogram being controlled, in one direction, by ui. flexible traction member, the end of which is attached to a catch secured to the side lever of the parallelogram located on the outside and, in the other direction, by a return spring bearing against one of the said side levers, and in that it comprises stopping means arranged so as to limit the pivoting of the upper support relative to the support leg and the pivoting of the chain guide device relative to the lower support under the action of their respective springs and of the means of abutment arranged so as to limit the deformations of the parallelogram in both directions, these abutment means being manually adjustable. 1. Gear-changing device according to claim 14, characterized in that said upper and lower supports are identical and sollt each formed by a sheet metal element cut and bent in the form of a double clevis, the two wings of the clevises of said supports located in RTI ID="0004.0542" WI="10" HE="4" LX="1596" LY="2373"> look Fune 1'autre bearing parallel axes extending from one wing to the other and on which sollt articulated the ends of said side levers freely. 2. A gear change device according to claim, characterized in that said upper support is rotatably mounted gart, with this axis and, on the other hand, with the said Support, and in that a washer angularly integral with the said axis and placed between the said Support and the support lug has radial abutment lugs folded in opposite directions and Tune of which rests against the support leg, while the other Limits the first pivoting towards the rear of said support. 3. Gear change device according to claim, characterized in that the first chain guide device comprises a flange and a counter-flange between which are pivot6s two rollers and is angularly integral with a shaft mounted rotating in said lower support, a torsion spring enrou16 around said coop6erant axis, on one side, with the latter and, on the other side, with said lower support. 4. A gearshift device according to claim and sub-claims 2 and 3, characterized in that each of said torsion springs is logo between the two wings of one of. yokes of the corresponding Support and is arranged inside a protective sleeve extending between these two wings. 5. Device for changing gears according to claim and sub-claim 3, characterized in that a fictitious line passing through the centers of the two rollers of the chain guide device is spaced away from the axis of pivoting of said device in the lower support. 6. A gear change device according to claim, characterized in that said return spring of the articulated para1161ogramme is constituted by a torsion spring housed for the most part in the first upper support and comprising a strand fixed to this support and a strand abutting against the inside face of the outside side lever of the parallelogram. 7. Gear-changing device according to claim, characterized in that the stop means limiting the 66formations of the para1161ogramme comprise a flap of the outer lever which extends near a threaded rod fixed along the inner lever, so as to cooperate with two knurled nuts screwed onto said rod, at least one spring-brake 6being mounted around the rod and immobilizing said nuts. B. Gear-changing device according to claim, characterized in that said flexible traction member consists of a cable in a sheath, the end of the sheath resting on a sheath stop located on the axis of articulation of the inner side lever On RTI ID="0005.0277" WI="3" HE="4" LX="516" LY="2309"> the 1st Upper Support, and the end of the cable being fixed to a catch of the external lever, said catch being more closer to the lower support than to the upper support and advanced with respect to the upper pivoting point of said lever, to increase the length of the lever arm from the point of attachment of the end of the cable. 9. Gear change device according to claim and sub-claims 2 and 3, characterized in that said lower and upper hinge pins are mounted in the wings of one of the yokes, of the corresponding support, each by two bearing conical with opposite conicities, one of these bearings being integral with the body of the hinge joint, while the other is made up of a cone which is axially movable with respect to said body, with a view to adjusting and taking up play. 10. Gear change device according to claim and sub-claims 2, 3 and 9, characterized in that it comprises means for locking the mobile cone comprising a counter-nut screwed onto the end of a threaded bearing surface. of the hinge body, this counter-nut abutting against the mobile cone by means of a washer sliding axially on said threaded port6e but. dopt the angular position is fixed due to the co-operation of flats of the washer and said axis. 11. Gear change device according to claim and sub-claims 2, 3 and 9, characterized in that it comprises means for locking the mobile cone comprising a screw screwed Jans the end of a threaded port6e of the fax body of articulation, the head of this screw abutting against the first movable cone. 12. Gear change device according to claim and sub-claims 2, 3 and 9, characterized in that it comprises means for locking the mobile cone comprising a screw having a conical bearing surface and which is screwed into the end of a threaded seat of the body of the hinge pin, said threaded seat of the pin having an internal cone shaped to cooperate with the conical seat of the screw and at least one radial slot allowing its expansion to biocate the 1st mobile cone. 13. Gear-changing device according to claim and sub-claim 6, characterized in that said torsion spring is threaded onto a support shaft resting by its ends on the two wings of the lower yoke of the upper support. , this torsion spring comprising two parts with contiguous turns and opposite winding directions, central strands dopt the end bears against the 1st outer side lever of the RTI ID="0005.0547" WI="25"HE="4" LX= "1654" LY="2178"> para1161ogramme and end strands engaged in holes formed in the bottom of the Upper Support. 14. Gear change device according to claim and sub-claims 6 and 13, characterized in that said central strands are joined at their ends so as to form a double brauch.