CN1119007A - Gearboxes for two-wheeled vehicles - Google Patents

Abstract

The present invention relates to a transmission for a two-wheeled vehicle, in particular a bicycle. At least two link plates (11, 12) of different sizes are arranged on the pedal shaft, and the chain can be selectively meshed through a first gear shifting device with a chain lifting wheel fork; on the rear wheel axle, a plurality of small chain wheels of different sizes are arranged, which can be selectively engaged by means of a second shifting device and a reversing device, wherein the transmission is operated by means of a cable (14, 15) which is enclosed in each case. The novel speed change device is characterized in that: the link plates (11, 12) are axially displaceable relative to the foot shaft (10) and can be selectively displaced into a number of positions corresponding to the number of link plates relative to the chain lifting fork (13) by means of a first shifting device, and the link plates (11, 12) and the chain lifting fork (13) can be displaced axially relative to the foot shaft by means of a second shifting device and a tilting device simultaneously, so that the chain runs in approximately one plane in all positions.

Description

Gearboxes for two-wheeled vehicles

The invention relates to a transmission of a two-wheeled vehicle, in particular a transmission according to the general concept of claim 1 of a bicycle.

Transmissions of this type are well known in practice. It includes up to 3 chain plates and 7 small sprockets. So, theoretically, it could have 21 gears.

In this known transmission, not only the sprocket, but also the pinion is always fixedly mounted. The conversion of the chain on the sprocket is realized by lifting the chain wheel fork. By operating the shifting device, the chain wheel fork pushes the chain to the desired chain plate.

The corresponding conversion of the chain on the small sprocket is accomplished by a turning device. While this device will be controlled by the second shifting device, the chain will move to the pinion selected at that time.

A disadvantage of this known transmission is that in some gears the chain will run at an extreme inclination. Therefore, not only will shifting be difficult, but it will also suffer from severe wear and tear.

As a consequence, the gears in these unfavorable positions were practically never used.

The object of the present invention is to further develop this type of transmission so that in all gears the chain can be kept approximately in the same plane, thereby avoiding tilting movements which are subject to wear.

The object of the invention is achieved in that a transmission having the features indicated in claim 1 is used.

Because the chain plate is movably arranged along the axial direction of the pedal shaft, and can be selectively moved to the positions corresponding to the number of chain plates relative to the chain wheel fork by the first shifting device. And due to the simultaneous use of the second shifting device and the overturning device, the chain plate and the chain wheel fork can move along the axial direction of the pedal shaft. At this time, the chain will approximately remain in one plane in all states. All this will have the effective result that the chain will then only move within the distance of one pinion to the next pinion, it will remain in one plane; stay in this plane.

The overturning device is in line with the existing technical status, so this paper will not discuss it any more.

The effective design also lies in that the chain plate is made into a gear ring and is fixed on the supporting disc. There are a large number of through holes along the circumferential direction on the disc, and a corresponding number of pins can slide through the through holes. One end of the pin is Fixed on the disc, the supporting disc is fixed on the pedal axle. This completes a virtually tilt-free, precisely guided axial bearing structure.

In a preferred scheme it is designed as follows:

The first shifting device has a bushing on which a rolling bearing is mounted, the bearing supports the support disc outside, the bushing is concentrically arranged on the pedal shaft, and a coil spring is contained in the bushing, and one end of the spring rests on the Set on the ring on the sleeve, the other end rests on a shell mounted on the bicycle frame and surrounds the pedal axle. The sleeve has an additional part, which is parallel to the axis of the pedal axle Extends out and into the body of the car. At this time, the cable of the first shifting device is fixed on this additional part; in the second shifting device there is a slider, which is mounted axially displaceable in the housing and has a The through hole for the cable and the support of a cable sleeve; for the cable of the second shifting device, it also has a reversing pulley, the end of the cable is fixed on the car shell, and it passes through the car A through hole on the shell leads to the outer wall, and the cable sleeve is against the outer wall of the car shell; the slider also has an arm protruding through the gap of the car shell, which drives the chain pulley fork and slides axially It rests on a bolt fixed to the bicycle frame.

The result is a very strong, stable structure which can be fitted to existing bicycles if some modification in the area of the pedal axle is tolerated.

The invention will now be further elucidated with the aid of the drawings. In the single figure, a cross-section of the transmission in the region of the pedal axle is shown. This only shows the main parts of the invention.

The figure shows the right part of a pedal axle 10 on which a disc 19 is screwed (threaded connection not shown) and indicates the arms of the pedals on the disc 19 in a known manner.

The brackets for the pedal axles are not shown in the figure, as they are well known to those skilled in the art.

The disc 19 supports the pins 18 arranged in the circumferential direction, protruding inwards, and axially parallel, and in this embodiment there are 8 pins in total.

The pedal shaft 10 is surrounded by a sleeve 20 at a certain distance, and a coil spring 22 is arranged in the inner chamber of the sleeve. One end of the coil spring leans against the outer ring of the sleeve 20, and the other end leans against the outer ring of the sleeve 20. On the shell 23 that is fixed on the bicycle frame. The sleeve 20 supports on its outer cylindrical surface a rolling bearing 21, here a ball bearing. On the outer surface of the rolling bearing 21 is a support disc 16 with through-holes 17 corresponding to the number and position of the pins 18, into which the pins 18 can slide. Two link plates 11 and 12 are fastened to the support plate 16, of which link plate 11 is the larger one.

The sleeve 20 has a projection 20' shown in the direction of the housing 23, on which projection the cable 14 is fastened, which cable is used for the first shifting device. Around the cable 14 there is a sleeve 14' fixed to a slider 24 which slides axially within the housing 23. A guide pulley 25 is provided on the slider 24 for guiding the cable 15 in the second shifting device.

The cable 15 is surrounded by a sheath 15' which is supported on the outside of the housing 23. Therefore, the cable goes like this: from a fixed point on the outside of the shell 23, through a through hole on the shell 23, then passes through the guide pulley 25, and is drawn out by another through hole on the cover 23, wherein the other through hole It is also the receiving point for the cable sheath 15'.

Slider 24 has an arm 26 which protrudes outwards through a slot in housing 23 and is guided onto a pin 27 which is fixed on the bicycle frame parallel to the axial direction of pedal axle 10 . On the free end of arm 26 is fixed with a chain roller yoke 13, and this chain roller yoke stretches out in the direction of chain plate as shown in the figure. Between the double arms of lifting chain wheel fork 13, run the chain not shown in the figure.

The working principle of the transmission is as follows:

To move the chain from the chain plate 12 to the larger chain plate 11, the first shifting device is used, in a known manner with a shift lever within reach of the rider, pulling the cable 14 , Sleeve 20 can move to the left in the figure shown because of the pressure of helical spring 22 like this, and in this process, the fixed lifting wheel fork has just moved chain from small chain plate 12 to large chain plate 11.

Obviously, in this shifting process, it can also be performed in reverse, the chain and the small sprocket are in the same plane.

To move the chain to an adjacent smaller sprocket, use the second shifter. This, in a known manner, will move the chain to the selected pinion by means of an overturning device, while a second shifting device comprising a cable 15 will be used. For example, if the cables 15 are loosened by moving the cable group 15 via the corresponding adjustment handle, as in the case of the first shifting device, the helical spring 22 forces the two chain plates 11 and 12 to press against the sleeve 20 and the arms 26 Slide block 24 is pressed to the right in figure with chain wheel fork 13, and wherein, the distance that moves is equivalent to the spacing of two pinions, like this, chain just remains in a plane. During this shifting process, there is no relative movement between the chain plates 12 and 11 and the chain roller fork 13, but they move relative to the pin 27 as a whole.

With the invention, all gears can be used without problems.

Claims (3)

1. It is suitable for two-wheeled vehicles, especially the transmission device of bicycles. The pedal shaft of the bicycle has at least two adjacent chain plates (11, 12) of different sizes. The sprocket fork (13) engages the chain in a selectable manner, and a plurality of adjacent small sprockets of different sizes are installed on the rear axle, and these small sprockets pass through a second shifting device with a turning device engage the chain in a selectable manner; Wherein the transmission device works through the cables (14, 15) which are wrapped respectively; It is characterized in that: the chain plate is installed on the pedal shaft and can move axially; it can be selectively moved to a position corresponding to the number of chain plates relative to the chain pulley fork (13) through the first shifting device; Through the second shifting device and using the turning device at the same time, the chain plates (11, 12) and the chain pulley fork (13) can be moved axially relative to the pedal shaft (10); In this way, the chain moves in almost one plane in all positions. 2. The speed change device according to claim 1, characterized in that: the chain plates (11, 12) are made into gear rings, which are fixed on a support disc (16), and the disc is provided with A plurality of through holes (17) arranged, the same number of pins (18) slide into the through holes, and one end of the pins (18) is fixed on the disc (19) fixed on the pedal axle. 3. The transmission according to claim 1 or 2, characterized in that the first shifting device comprises a sleeve (20), on which a rolling bearing (21) is arranged, which externally supports the A support plate (16), wherein the sleeve (20) is concentric with the pedal shaft (10) and contains a helical spring (22) in the inner space of the sleeve, one end of which is pressed against the sleeve (20) ) on a ring, the other end on a shell (23), the shell around the pedal shaft (10) is installed on the bicycle frame, wherein the sleeve (20) is parallel to the pedal shaft (10) The additional part (20'), which extends into the housing (23), the cable set (14) in the first shifting device is fixed on the additional part (20'); the second shifting device has a sliding block (24), the slider is axially movably supported in the housing (23); and a through hole through which the cable (14) of the first shifting device passes, and the bushing ( 14'), wherein the slider (24) also has a guide pulley (25) for the cable (15) of the second shifting device, the end of the cable is fixed on the shell (23) And be guided to the outer wall by a through hole on the shell (23), and the sleeve sleeve (15 ') of cable (15) is just supported on this point of the shell; The arm (26) that protrudes from the slit of 23) supports the chain wheel fork, and is slidably arranged in the axial direction on the pin (27) that is fixed on the bicycle frame.

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