JPH1016867A - Rear derailer for bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bicycle rear derailer capable of reducing the possibility of damaging caused by contact with a foreign object by suppressing a projection to the side of a car body. SOLUTION: A guide pulley 5 and a guide pulley supporting member 7 are connected to each other by a guide pulley shaft 3, a tension pulley 6 and a tension pulley supporting member 8 are connected to each other by a tension pulley shaft 4 and the guide pulley supporting member 1 and the tension pulley supporting member 8 are connected to each other by a connecting part 2. A distance between the guide pulley shaft 3 and the tension pulley shaft 4 is made variable, a spring for pressing the guide pulley shaft 3 and the tension pulley shaft 4 to be narrowed in the distance therebetween is disposed in the connecting part 2 and, by using the spring for both chain laying and chain tension adjusting, the necessity of providing a plurality of springs is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses at least two pulleys to change a chain between sprockets around a rear hub, and to absorb a slack of the chain caused by the change of the chain, thereby making the chain suitable for the chain. The present invention relates to a bicycle rear derailleur that adds tension, that is, adjusts the tension of a chain.

[0002]

2. Description of the Related Art A conventional bicycle rear derailleur, hereinafter referred to as a rear derailleur, has a guide pulley and a tension pulley connected to a single pulley support via respective pulley shafts, and the guide moves along with the pulley support. The chain is changed and the tension of the chain is adjusted via the pulley and the tension pulley.

[0003]

Since the conventional rear derailleur has a structure in which at least two springs, ie, a spring for changing the chain and a spring for adjusting the tension of the chain, are built in, the rear derailleur is directed to the side of the vehicle body. It is difficult to suppress the protrusion. As a result, there is a problem that the possibility of breakage due to contact with an external object increases. SUMMARY OF THE INVENTION It is an object of the present invention to provide a rear derailleur that reduces the possibility of breakage due to contact with an external object by suppressing a protrusion to the side of the vehicle body.

[0004]

In the rear derailleur of the present invention, a guide pulley and a guide pulley support member are connected via a guide pulley shaft, and a tension pulley and a tension pulley support member are connected via a tension pulley shaft. Coupling, connecting the guide pulley support member and the tension pulley support member via a connecting portion, to make the center distance between the guide pulley shaft and the tension pulley shaft variable,
A spring for biasing the guide pulley shaft and the tension pulley shaft in a direction to reduce the distance between the shafts is disposed at the connecting portion.

In the rear derailleur of the present invention, a spring for changing the chain and a spring for adjusting the tension of the chain are combined with the spring disposed in the connecting portion, so that the spring is not built in a plurality of places. Thus, the protrusion to the side of the vehicle body can be suppressed. As a result, the possibility of breakage due to contact with an external object is reduced.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments will be described with reference to the drawings. 1, 2 and 3, a base member 12 connected to the vehicle body F via mounting bolts 17 and a bracket member 9 are connected via a bracket shaft 13, and the bracket member 9, the inner tension link member 10 a, Outer tension link member 10b, tension pulley support member 8
Are sequentially coupled via pins 14a, 14b, 14c, and 14d to form a parallel crank mechanism. The tension pulley support member 8, the tension pulley 6, and the outer member 2b of the connecting portion 2
Are connected via a tension pulley shaft 4 so that the base member 1
2. The guide link member 11 and the guide pulley support member 7 are sequentially connected via pins 15a and 15b, and the guide pulley support member 7, the guide pulley 5 and the inner member 2a of the connecting portion 2 are connected via the guide pulley shaft 3. I do.

The chain guides 16a and 16b are arranged on the side of the guide pulley 5, and the chain guides 16c and 16b
d is arranged on the side surface of the tension pulley 6. The chain C is located on the front side of the front gear (not shown),
, The front side of the guide pulley 5 and the rear side of the sprocket S. The operation wire W is fixed to the guide link member 11.

In FIG. 4, a spring 1 is disposed between an inner member 2a and an outer member 2b. When one of the inner member 2a and the outer member 2b slides with respect to the other, the connecting portion 2 expands and contracts.

In FIG. 2, an operation for opening the center distance between the guide pulley shaft 3 and the tension pulley shaft 4 or a spring 1 (not shown) for reducing the center distance between the guide pulley shaft 3 and the tension pulley shaft 4 is shown. With the return by the urging, the connecting portion 2 expands and contracts, and the guide pulley 5 and the tension pulley 6 move in parallel in the vehicle width direction with respect to the base member 12 coupled to the vehicle body F (not shown). By this movement, the chain C is moved via the guide pulley 5 and the tension pulley 6.
(Not shown).

In FIG. 3, the tension pulley 6 swings clockwise about the bracket shaft 13 by the urging of a spring 1 (not shown) for reducing the distance between the guide pulley shaft 3 and the tension pulley shaft 4. Move. At the same time as the guide pulley 5 and the tension pulley 6 are moved in parallel with the base member 12 in the vehicle width direction, the tension pulley 6
Swings clockwise or counterclockwise about the bracket shaft 13. That is, the tension pulley 6 is vertically displaced with respect to the guide pulley 5. With this displacement, the tension of the chain C is adjusted via the guide pulley 5 and the tension pulley 6.

[0011]

According to the rear derailleur of the present invention, the spring is not built in a plurality of places and the protrusion to the side of the vehicle body can be suppressed. As a result, the possibility of breakage due to contact with an external object can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view of an attached state showing an embodiment of the present invention.

FIG. 2 is a plan view showing an embodiment of the present invention.

FIG. 3 is a front view showing an embodiment of the present invention.

FIG. 4 is a sectional view of a connecting portion.

[Description of Signs] 1 Spring 2 Connecting part 3 Guide pulley shaft 4 Tension pulley shaft 5 Guide pulley 6 Tension pulley 7 Guide pulley support member 8 Tension pulley support member

Claims (1)

[Claims] 1. A guide pulley (5) and a guide pulley support member (7) are connected via a guide pulley shaft (3),
Also, the tension pulley (6) and the tension pulley support member (8) are connected via a tension pulley shaft (4),
The guide pulley support member (7) and the tension pulley support member (8) are connected via a connecting portion (2), and an inter-axis distance between the guide pulley shaft (3) and the tension pulley shaft (4). Rear derailleur for bicycles that can be changed.