JPH0140362Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The invention is based on a bicycle drive chain, in particular, transmits power from the multi-stage front sprocket attached to the crankshaft to the multi-stage rear sprocket attached to the rear wheel hub to drive the rear wheel. This relates to a transmission chain that is driven.

(Prior art) A typical bicycle chain consists of an inner link plate in the shape of a lion, a bearing section with pins and bushes as nodes, and an endless multi-joint structure with rollers attached to the outer periphery of the bush. It is the body. However, when this type of chain is wound around a multi-stage front sprocket and a multi-stage rear sprocket and used for shifting, the shifting performance is poor and smooth shifting operations cannot be achieved. Therefore, a mechanism has been developed in which the shape of the link plate is modified to improve the shifting performance, one of which is Utility Model Publication No. 55-1988. In this transmission chain, the outer link plate is not shaped like a flat plate, but is made to protrude outward from both sides, thereby preventing both end surfaces of the pins from coming into contact with the sprocket, thereby improving the transmission performance. In addition, the transmission chain according to Utility Model Application Publication No. 53-151063 improves transmission performance by cutting out the portion corresponding to the lower center of the outer link plate and its surrounding area to reach near the pitch line. It is something.

(Problems to be Solved by the Present Invention) There are various ways to improve the shifting performance of the chain, but the present invention involves cutting out the lower center of the link plate and its surroundings. This type of chain is intended to improve the above-mentioned speed change performance. The transmission chain according to Utility Model Application Publication No. 53-151063 has the disadvantage that, when the sprocket is reversed, the chain may scrape up onto other sprockets or fall down, resulting in a lack of stability. ing. It is not enough for a speed change chain to simply have excellent speed change performance; it must avoid the phenomenon of the sprocket lifting up or falling off when unnecessary, and the speed change chain according to the present invention has the following characteristics: The objective is to achieve both speed changeability and stability.

(Measures to solve the problem) Stability can be increased by making the chain link shape into a lion shape, and by forming a constriction at the bottom of the center,
On the contrary, the shifting performance is improved, and the first feature of the present invention is that the constricted link is used as an inner link,
The external link is a dot shaped like a hyotan.

The second feature is that if all the inner links were waist links, the stability would be degraded, so waist links are used only on one side.

The third feature, however, is that if a constricted link is provided only on one side, the shifting performance to one side is good, but the shifting performance to the other side is degraded, so the constricted link is provided alternately one pitch at a time. The point lies in the use of links. Therefore, in the transmission chain, the inner links are connected and arranged so that the left and right directions of the inner links are changed every other pitch.

EMBODIMENT OF THE INVENTION Hereinafter, one embodiment of the transmission chain according to the present invention will be described in detail based on the drawings.

(Example) Figures 1 and 2 show one form of a bicycle chain for shifting according to the present invention, and 1 is an outer link plate;
2 is an inner link plate, 3 is a constriction link plate, 4 is a pin, 5 is a bush, 6 is a roller,
These constitute an endless multi-segmented body connected to each other. The structure of each of these parts is no different from that of a conventional bicycle chain, but the outer link plate 1 has a partial surface 7 formed at the constriction in the center, and the surfaces 7, 7 are directed inwardly toward each other. Built-in for. On the other hand, the inner link plate 2 and the waist link plate 3 have a surface 8 over the entire circumference.
, and these surfaces 8, 8 are arranged so as to face each other inward.

Of course, the transmission chain according to the present invention has the surface 7,
8 is not an essential requirement and does not necessarily have to be formed.

By the way, the roller link has inner link plate 2.
The constriction link plates 3 are press-fitted into both sides of the bushing 5, and the direction of the constriction link plates 3 is alternately changed for each pitch.

As shown in Fig. 2, the constriction link plate 3 has a large constriction 9 formed at the lower center (inward in the radial direction when wrapped around the sprocket), and the constriction 9 reaches nearly to the pitch line M-M. .
Of course, the size of the constriction 9 is not determined in absolute terms here, but is determined relatively based on the chain pitch, sprocket shape, and other dimensions and shapes of the chain, taking into account speed change performance and stability.

As described above, the transmission chain according to the present invention uses a constriction link plate 3 on one of the inner links constituting the roller link, and the constriction link plate 3 is alternately arranged at each pitch. You can get the following effects.

(Effects) The transmission chain according to the present invention not only has good transmission properties, but also has excellent stability without causing phenomena such as lifting or dropping when unnecessary. In other words, by arranging the constriction link plate 3 only on one of the inner links and alternating directions, it is possible to achieve both speed changeability and stability as the speed change chain.

[Brief explanation of the drawing]

1 and 2 show one embodiment of the bicycle chain for shifting according to the present invention, with FIG. 1 showing a plan view including a cross section, and FIG. 2 showing a front view. 1... Outer link plate, 2... Inner link plate, 3... Narrow link plate, 4... Pin, 5... Bush, 6... Roller, 7, 8...
Face, 9...constriction.

Claims (1)

[Scope of utility model registration request] In a bicycle chain that is wrapped around a multi-stage front sprocket and a multi-stage rear sprocket to enable speed change, one of the roller link plates that make up the chain is a gourd-shaped inner link plate, and the other is a constriction link. A bicycle chain for shifting characterized by alternating the arrangement direction of the plates at each pitch.