JPS6010957Y2 - Bicycle transmission pulley - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a transmission pulley in a bicycle transmission, and more specifically, to a transmission pulley that is rotatably supported on a pulley shaft provided in a transmission frame of the transmission. It is.

Conventionally, this type of shift assist pulley (hereinafter simply referred to as a pulley) has either been made entirely of metal, such as a light aluminum alloy, or made entirely of synthetic resin, made of a wear-resistant synthetic resin material. Ta.

By the way, generally, a bicycle transmission moves the pulley in the axial direction of the pulley shaft via the hanging frame.
The drive chain 7 suspended on the pulley is guided to any one of the multistage sprockets, and at this time, the drive chain 7 is guided by
The chain line is displaced in the axial direction of the pulley shaft.

Therefore, when the chain line is displaced as described above, if the pulley is made of conventional all-metal or all-synthetic resin, the teeth of the pulley will strongly abut against the link plate of the chain 7. As a result of an unbalanced load acting on the pulley, there is a problem in that rotational resistance is generated in the pulley and the pulley does not rotate smoothly.

Furthermore, when the teeth of the pulley come into contact with the check 7, if the pulley is made entirely of metal or synthetic resin as in the past, there is a problem in that the so-called ringing of the check 7 occurs. It was.

In view of these circumstances, the present invention forms the tooth portion where the roller of the check 7 engages and the contact portion where the link plate of the check 7 contacts with an elastically deformable rubber material, and connects the contact portion to the pulley shaft. It is an object of the present invention to solve the above-mentioned problems by providing a pulley for a transmission that is held in a pulley body that is freely rotatably supported.

Hereinafter, the configuration of the present invention will be explained according to the embodiment shown in the drawings.

In FIGS. 1 and 2, reference numeral 1 denotes a pulley body made of a metal material such as an aluminum light alloy, which is divided into two parts 11 and 12 in the axial direction. Annular grooves 13 and 14 are formed on one side of the divided body 11 and 12, and shaft holes 15 and 16 are formed through the center.

Incidentally, the pulley bodies 1, 1 may be formed from a wear-resistant synthetic resin material.

Further, reference numeral 2 denotes an annular tooth body consisting of a plurality of tooth parts 21, 21, which are engaged with the rollers of a chino (not shown), and a contact part 22, which is in contact with a link plate of the chino. The body 2 is made of an elastically deformable rubber material.

Thus, this tooth body 2 is divided into the above-mentioned pair of divided bodies 11 and 12.
and insert the screw 3 into the through hole 17.18 formed through the annular groove 13.14 of the divided body 11.12 and the through hole 23 formed through the tooth body 2, and The pulley main body 1 cut out from these divided bodies 11 and 12 and the tooth body 2 are integrally joined by caulking the tips of the parts 3 to form a pulley.

The pulley of the present invention formed as described above is rotatably supported on a pulley shaft 5 installed on a changing frame 4 of a transmission as shown in FIG. 2, while a cap 51 supported on the pulley shaft 5 .51 is loosely inserted into the annular groove 13.14 formed in the split body 11.12 of the pulley main body 1.

When the chino is guided by the pulley to any one of the multi-stage sprockets and the chino line of the chino is displaced in the axial direction of the pulley shaft 5, the teeth 21 of the tooth body 2 of the pulley... - And the contact portion 22 is also displaced in the axial direction of the pulley shaft 5 in response to the displacement of the Cheno line.

That is, as the cheno line of the cheno is displaced,
As a result of the contact portion 22 of the tooth body 2 being pressed by the link plate of the chino, the tooth portions 21, 21, . The pulley rotates smoothly by being displaced in the same direction.

Furthermore, since the teeth 21, 21... and the contact part 22 are made of a rubber material as described above, these teeth 21, 21... and the contact part 22 provide elasticity to the chino. Therefore, the chino is driven quietly without making any noise.

Incidentally, in the present invention, instead of the above embodiment, as shown in FIGS. 3 and 4, a divided body 11.1 in the pulley main body 1 is provided.
2 are brought into close contact with each other, and stepped portions 19 and 20 are provided on the outer periphery of each of these divided bodies 11 and 12, respectively, and between these stepped portions 19 and 20, the contact portion 2 of the tooth body 2 is
2 may be held in between.

In this case, the divided bodies 11 and 12 may have the same shape, but as shown in FIG.
5' may be formed, and the other divided body 12 may be incorporated therein.

In either case, the divided bodies 11, 12 are integrally joined by the aforementioned fixing method using screws, welding, or other fixing means.

Further, in the above embodiments, the pulley main body 1 is constituted by a pair of divided bodies 11 and 12, but as an integral structure, a recessed part is formed in the outer peripheral part as shown in FIG. 4, The tooth body 2 may be elastically deformed to fit into the recessed portion.

As described above, in the pulley of the present invention, the teeth with which the rollers of the chain engage and the contact part with which the link plate of the chain comes into contact are formed of an elastically deformable rubber material, and the contact part is connected to the pulley shaft of the hanging frame. Since the teeth are engaged with the rollers of the chain and the contact part contacts the link plate of the chain, these teeth and the contact part are made of rubber material. Therefore, so-called chino noise will not occur, even if the chino line of the chino, which is guided by the pulley to one of the multi-stage sprockets, is displaced in the axial direction of the pulley shaft. Since the tooth portion and the contact portion are displaced in the same direction as the Cheno line, the pulley body rotates extremely smoothly without any unbalanced load acting on it.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and Fig. 1 is a right side view with the cap removed, Fig. 2 is a longitudinal sectional view showing the pulley of the invention supported on the transmission frame, and Fig. 3. 4 is a right side view with the cap removed showing another embodiment.
The figure is a partially cutaway side view of the embodiment shown in FIG. 3. 1...Pulley body, 2...Tooth body, 2
1...Tooth part, 22...Contact part, 3...
...screw, 4...replacement frame, 5...
Pulley shaft, 51...cap.

Claims (1)

[Scope of utility model registration request] A pulley that is rotatably supported on a pulley shaft of a change frame in a bicycle transmission and guides a bicycle driving roller chain, and has toothed portions with which the rollers of the chain 7 engage, and a link plate of the chain 7. The contact part that comes into contact with
A pulley for a bicycle transmission, characterized in that it is formed of an elastically deformable rubber material, and the contact portion is held by a pulley body that is rotatably supported on the pulley shaft.