JPH0376277B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention consists of two sprocket segments with a sector angle of approximately 180°, which by means of a spring-loaded lever device allow the driver to apply energy to the crank. Adjustable sprockets and kinematics for the best possible use of the cyclist's energy, such that the outer diameter of the sprocket in the part where it feeds can be larger than the diameter in other parts. The present invention relates to a combination device.

Such a sprocket and transmission combination is known from US Pat. No. 3,798,989.
This known sprocket has small auxiliary sprocket segments for bridging the spacing between sprocket segments having a sector angle of about 180° so that the relative spacing of the sprocket segments can be adjusted. . The connection between the sprocket segments is made by these small auxiliary sprocket segments, which urge the sprocket segments forward when the pedal is depressed forward.
The sprocket segments are constrained between the discs to prevent "spin". Known sprockets are complex, therefore heavy, and are difficult to operate due to dust ingress.

Additionally, the presence of the small auxiliary sprocket segments rather limits the maximum speed that can be generated. Each rotation of the sprocket creates a large angle in the chevron, which results in poor running flexibility and irregular and high wear. Furthermore, the Chivun makes a rattling noise when the pedal is pressed too quickly in a high position.

The aim of the invention is to prevent the above-mentioned drawbacks.

According to the invention, this object is achieved by connecting one of the cranks to each sprocket segment by a crank hinge pin, which crank hinge pins are connected to a recess in one of the sprocket segments near the outside diameter of the sprocket and in the circular state of the sprocket. A lever device is located on the protrusion of the other sprocket segment that fits into the transmission, and the lever device has a fixed hinge pin at its outer end and can be moved to various positions in the adjustable groove of the other sprocket segment at the other end. It consists of levers with pins, each sprocket segment being loaded toward each other by a spring around a crank hinge pin, and the levers being loaded by a spring around their lever hinge pin in a direction away from the crank. This can be achieved by

In an advantageous embodiment, the lever consists of a rod bent towards the other end to form a transmission pin that projects through the adjustment groove and is thereby adapted to cooperate with the pin of the transmission mechanism. The transmission block is provided on the rear side of the sprocket.

A simple embodiment is obtained by matching the hinge pin at the outer end of the lever with the crank hinge pin.

The transmission pin of the transmission mechanism, together with the transmission block placed near the outside diameter of the sprocket, serves to expand the sprocket. The transmission pin of the transmission mechanism is preferably placed on an adjustable piece carrying a rotatable pawl with two stop sliding ends that fall into recesses in the stop segment.

The present invention will be described in detail below based on embodiments shown in the drawings.

The sprocket shown in different states in FIGS. 1 and 2 has two sprocket segments 1, each having a sector angle of approximately 180°.
It consists of 2. Teeth 3 are provided on the outer periphery of these sprocket segments 1 and 2.
meshes with a chain (not shown). Arrow 4 indicates the direction of the chain. The sprocket segments 1, 2 are provided with several holes 5 to save weight.

Both sprocket segments 1, 2 have projections 6
and a recess 7, which can be clearly understood from FIG. Sprocket in a circular state (Fig. 1)
In the sprocket, the projections 6 are completely fitted into the corresponding recesses 7, and in the expanded state of the sprocket (FIG. 2) the projections 6 are spaced apart from the recesses 7. As will be described later, by placing the pivot point of the lever device in an appropriate position, the device for expanding and contracting the sprockets will expand and contract one sprocket segment, and the other sprocket segment. It is possible to prevent the tooth pitch "t" or "nt" of the sprocket from changing significantly when the sprocket is not in use.

Both projections 6 are interconnected by a crank 8. This crank 8 has a hole 9 for a pedal axle (not shown), into which the pedal axle is fixed, as is well known, by, for example, a threaded pin passing through a small hole 10. The connection between the protrusion 6 and the crank 8 is provided by crank hinge pins 11 and 12.
These crank hinge pins 11, 12 are loaded in opposite directions by the spring 13, i.e. the spring 13 directs one sprocket segment towards the other so that the sprocket becomes circular. to press.

Note that the projection 6 is pulled when the pedal is depressed in the forward direction, so that the rotation of the pedal shaft in FIGS. 1 and 2 corresponds to the direction of rotation of the clock.

The lever arrangement consists of two levers 14, 15, each of which has a fixed hinge pin 16, 17, which hinge pin 16, 17 is fitted in a suitable position outside the crank hinge pin 12, 11 in the projection 6, respectively. It is placed in a place. The positions of these fixed hinge pins 16 and 17 are determined by the lengths of the levers 14 and 15 and the positions of the fixed hinge pins 16 and 17.
In relation to the angle between the sprocket and the crank 8, one of the sprocket segments 1, 2 must be positioned such that the tooth pitch t of the entire sprocket does not change significantly during adjustment of expansion and contraction.
This is because the sprocket adjustment is done in two stages: first, when the pedal is rotated 180 degrees in the forward direction, the first sprocket segment is adjusted to expand or contract, and then when the pedal is rotated more than 360 degrees in the forward direction. The second sprocket segment expands when
This is because the size is adjusted to be reduced.

The levers 14 and 15 each have a transmission pin 1 at one end.
8A, 18B, these transmission pins 18A,
18B can be moved into various recesses in the adjustment grooves 19 provided in the sprocket segments 1, 2 during expansion of the sprocket. Hinge pins 16, 17
Spring 20 is also provided around these springs 2
0 acts to move the levers 14, 15 radially away from the crank 8.

The levers 14, 15 can be constructed from a pair of very thin plates on either side of the sprocket segments 1, 2, but they can also be made from a rod bent to one side to form the transmission pin 18.

In addition, the fixed hinge pin 16 of the levers 14, 15,
The construction can also be simplified by making 17 coincident with the crank hinge pins 11, 12.

2 of the transmission mechanism 22 in FIGS. 1 and 2.
The real pins 21, 21' are shown, and this transmission mechanism 2
2 is fixed to a seat pipe 23 of a bicycle frame, for example. The drawing also shows a pipe 24 leading towards the handlebars in the bicycle frame and a fork 25 leading towards the rear wheel.
One pin 21 is used to expand the sprocket and the other pin 21 is used to contract the sprocket. Both of these pins 2
1, 21' are the two sprocket segments 1,
Transmission block 2 rotatably installed on the back of 2
Operate 6.

In FIGS. 1 and 2, one of the two transmission mechanisms 22 located on the rear side of the sprocket segments 1, 2 is shown in broken lines as a block 26 on the rear side of the sprocket segments.

When expanding the sprocket segments 1, 2, these blocks 26 have no effect; when retracting the sprocket segments 1, 2, the levers 14, 15
firstly opens its adjustable end 18 during transmission.
A and 18B are lifted from their seats and then engaged in a lower position. This provides flexible transmission. Since adjustment of the sprocket segments is performed at the position where the chain and sprocket teeth engage or disengage, which is the position farthest from the center of rotation, the positions of the frame to which the transmission mechanism 22 is fixed are naturally limited.

Furthermore, the transmission mechanism 22 shown in FIG. 3 has an adjustable piece 27 which is operated by a handle 28 shown in FIG. This adjustable piece 27 is moved by a rotatable pawl 29 connected to the handle 28 via a push-pull cable 30.

During adjustment, this rotatable pawl 29 fits into a recess in a stop segment 31, which is rigidly connected to a fixed part 32 of the transmission mechanism 22.

The transmission mechanism 22 operates as follows. That is, the pawl 29 is placed in the next position by a push/pull cable 30 operated by a handle 28 on a bicycle handlebar (not shown). The pawl 29 has two stop sliding ends 29A and 29B and is rigidly connected to the operating piece 29C for the cable 30. The pawl 29 is rotatable about an axis 32 on the back side of the movable adjustable piece 27 which can be rotated about a pin 33.

By moving the handle 28 to a higher or lower position, the transmission pins 21, 21' respectively engage the transmission block 26 of the first sprocket segment when the driver depresses the pedal.

When the pedal is further depressed, the transmission pins 21, 2
1' and transmission block 26 engage to move the first sprocket segment toward the expanded or retracted position. If the driver continues to press the pedal, the second sprocket segment separates from the chain, rotates, and expands and contracts in the same way as the first sprocket segment.

After the first and second sprocket segments are aligned, they do not engage the transmission block 26.

Thus, a pedal rotation of 180 degrees adjusts one sprocket segment, and a pedal rotation of 360 degrees or more adjusts both sprocket segments. FIG. 5 shows the lever devices 14, 15, the transmission block 26 and the adjustable piece 27 in an exploded view.

The transmission block 26 is rotatably connected to the sprocket segments 1, 2 by pins 35. The entire transmission block 26 consists of four members 26, 2.
6A, 26B, and 26C, which are movably connected to each other.

Member 26A is rotatably attached to sprocket segments 1, 2 by pin 35. This member 26A is biased toward the cam 37 by a spring (not shown), and can rotate about the pin 35 with the limit of the position where it engages with the cam 37. The transmission block 26 is connected to the member 26A.
It is rotatably attached to a pin 36 provided in the. A spring (not shown) holds the transmission block 26 in a fixed rest position. Since this spring is a double-acting spring, the transmission block 26
can rotate clockwise and counterclockwise about pin 36.

The adjustable piece 27 is attached so that it can rotate in the direction of the arrow shown in the figure. Adjustable piece 27
When the pin 21' provided on the adjustable piece 27 rotates in the direction L, the pin 21' provided on the adjustable piece 27 engages the portion 4 of the transmission block 26.
1. Conversely, when the adjustable piece 27 is rotated in the direction H, the pin 21 provided on the adjustable piece 27 comes into contact with the portion 40 of the transmission block 26.

Member 26B is the link between members 26A and 26C. The member 26C is the transmission pin 18A and 18B.
It is rotatably connected to the ends of the levers 14 and 15.

Expansion and expansion of sprocket segments 1 and 2 are shown below.
The reduction adjustment operation will be explained.

When the driver moves the handle 28 to switch from the low position to the high position, the adjustable piece 27 moves to the fourth position.
It rotates in the direction H shown in the figure. After the adjustable piece 27 has rotated in direction H, when the driver rotates the pedal in the forward direction, the transmission block 26 rotates with the sprocket, causing the portion 40 of the transmission block 26 to rotate.
engages the pin 21 of the adjustable piece 27. As the sprocket continues to rotate, the transmission block 26 rotates clockwise while contacting the pin 21. As the transmission block 26 rotates clockwise, the member 26A is connected to the pin 35 via the pin 36.
can be rotated clockwise using the fulcrum. Part 2
6A rotates clockwise about the pin 35, so that the tips of the levers 14 and 15 touch the member 26.
It is pulled up from the recess via B and 26C and moved to a position far from the center of the sprocket. By rotating the sprocket by a predetermined angle, the transmission block 26 is separated from the pin 21 of the adjustable piece 27.
The tip of the lever 14 is connected to the adjustment groove 1 that is engaged at that time.
It is fixed in the recess of 9. Adjustment groove 19 where the tips of levers 14 and 15 are far from the center of the sprocket
By engaging with the recesses of the sprocket segments 1 and 2, the sprocket segments 1 and 2 are adjusted downward, resulting in a higher transmission ratio of the bicycle.

Conversely, when the driver switches the handle 28 from a high position to a low position, the adjustable piece 27 rotates in the direction L shown in FIG. When the driver rotates the pedal in the forward direction after the adjustable piece 27 has rotated in the direction L, the transmission block 26 rotates with the sprocket, and the portion 41 of the transmission block 26 rotates in the direction L. It engages with pin 21'. As the sprocket continues to rotate further, the transmission block 26 rotates counterclockwise while contacting the pin 21'. As the transmission block 26 rotates counterclockwise, the member 26A is rotated counterclockwise via the pin 36 with the pin 35 as a fulcrum. As the member 26A rotates counterclockwise about the pin 35, the levers 14, 15
The tip of the sprocket is pushed by members 26B and 26C and moved to a position close to the center of the sprocket. By rotating the sprocket by a predetermined angle, the transmission block 26 is separated from the pin 21' of the adjustable piece 27.
The tip of the lever 14 is connected to the adjustment groove 1 that is engaged at that time.
It is fixed in the recess of 9. By engaging the tips of the levers 14, 15 with the recesses in the adjustment groove 19 located near the center of the sprocket, the sprocket segments 1, 2 are adjusted to expand, resulting in a lower gear ratio of the bicycle.

The joint member 34 shown in FIG.
The device is configured so that if it is moved unnecessarily, it will be adjusted one step at a time to either a higher or lower position each time. This is to ensure that the correct position is selected without any problems even in the dark. This position can be read using the transmission handle.

It should be noted that the sprocket can be used with a chain tensioner only if it is used as part of a chain replacement gear.

Embodiments other than those shown in the drawings are also included within the scope of the invention.

[Brief explanation of drawings]

Fig. 1 is a side view of the sprocket in a circular state, Fig. 2 is a side view of the sprocket of Fig. 1 in an expanded non-circular state, Fig. 3 is a side view of the transmission mechanism, and Fig. 4 is a side view of the sprocket of Fig. 1 in a non-circular state. A side view of the operating member, and FIG. 5 is an exploded perspective view of the lever device, transmission block, and adjustable piece. 1, 2... Sprocket segment, 6... Protrusion, 7... Recess, 8... Crank, 11, 12...
...Crank hinge pin, 14,15...Lever,
16, 17... Lever hinge pin, 18... Transmission pin, 19... Adjustment groove, 21, 21'... Pin,
22...Transmission mechanism, 26...Transmission block, 27
. . . Adjustable piece, 29 . . . Pawl, 31 . . . Stop segment.

Claims (1)

[Claims] 1. Consisting of two sprocket segments with a sector angle of about 180°, where these sprocket segments supply energy to the crank by means of a spring-loaded lever device. In an adjustable sprocket and transmission combination device for making the best possible use of the cyclist's energy, which are interconnected in such a way that the outside diameter of the sprocket in one part can be larger than the other part. , one of the cranks 8 is connected to each sprocket segment 1, 2 by a crank hinge pin 11, 12, which crank hinge pins 11, 12 are connected to each sprocket segment 1, 2 near the outer diameter of the sprocket and in the circular state of the sprocket. Located on the projection 6 of the other sprocket segment which fits into the recess 7, the lever device has fixed hinge pins 16, 17 at the outer end and an adjustable groove 19 of the other sprocket segment at the other end. lever 14,1 with a transmission pin 18 that can be moved to various positions;
5, each sprocket segment is loaded against each other by a spring 13 around a crank hinge pin 11, 12, and the levers 14, 15 are loaded around their lever hinge pins 16, 17 by a spring 20. An adjustable sprocket and transmission mechanism characterized in that it is loaded in a direction away from the crank 8. 2. A transmission block 26 provided on the rear side of the sprocket segment, consisting of a rod bent towards the other end to form a transmission pin 18 through which the levers 14, 15 protrude through the adjusting groove 19.
Adjustable sprocket and transmission mechanism according to claim 1, characterized in that the pins (21, 21') of the transmission mechanism (22) can engage with the pins (21, 21') of the transmission mechanism (22). 3. Adjustable sprocket and transmission mechanism according to claim 1 or 2, characterized in that the hinge pins 16, 17 at the outer ends of the levers 14, 15 coincide with the crank hinge pins 11, 12. . 4 Transmission mechanism 22 for expanding the sprocket
Adjustable sprocket according to any one of claims 1 to 3, characterized in that the transmission pins 21, 21' of the sprocket cooperate with a transmission block 26 located near the outer diameter of the sprocket. Sprocket and transmission mechanism. 5. The transmission pins 21, 21' of the transmission mechanism 22 are positioned on the adjustable piece 27 supporting a rotatable pawl 29 with two stop sliding ends 29A, 29B, the stop sliding Adjustable sprocket and transmission mechanism according to any one of claims 1 to 4, characterized in that the ends (29A, 29B) fit into recesses in the stop segment (31).