JPS593024Y2 - Bicycle exterior derailleur - Google Patents

Description

[Detailed description of the invention] This invention is an external transmission for bicycles, more specifically, a sumo frame with two pulleys that guides the driving chain to one of the multi-stage sprockets. This invention relates to an external bicycle transmission that can be moved to change gears.

Generally, this type of external transmission has a pantograph mechanism consisting of a base member with a bracket attached to the hawk end of the bicycle frame, a pair of links and a movable member, and the sumo frame is attached to the movable member. , a fixing device for the operating wire is attached to one of the two members that move relative to each other in the pantograph mechanism, and a supporting device for an outer cylinder that guides the operating wire is attached to the other, so that the movement due to the operation of the operating wire is fixed. The movable member is displaced in the axial direction of the multi-stage sprocket by the tensioning action of the outer tube against the movement of the wire, and the driving chain guided by the pulley is replaced with one of the sprockets.

By the way, in order to attach the middle part of the outer tube to the bicycle frame, it is most preferable that the support for supporting the outer tube is attached to the base member fixed to the fork end of the frame, but in this case, Since the support is located on the rear side of the bicycle from the fixing device for the operating wire, when the outer tube is stretched between the operation lever provided on the front side of the bicycle and the support, the outer tube There was a problem in that the curved portion was largely curved near the support, and this curved portion protruded to the side of the bicycle wheel and caught feet or the like.

In other words, if the support is on the rear side of the bicycle than the fixing device, the outer tube will be curved near the support, but if the radius of curvature at the curved portion of the outer tube is made smaller, The frictional resistance during relative movement between the cylinder and the operating wire becomes large, and the efficiency of transmitting the operating force by the operating lever deteriorates, so it is necessary to make the outer cylinder largely curved.

The present invention was devised in view of the above-mentioned conventional problems, and the purpose is to reduce the curvature of the outer tube near the support, and to stretch the outer tube along the chain stay of the bicycle frame. It is an object of the present invention to provide an external transmission that can be installed in an external gear, and that can reduce frictional resistance during relative movement between an outer cylinder and an operating wire.

Therefore, the present invention extends a bracket fixed to a stationary member of a bicycle toward the front side of the bicycle, and provides a support for an outer tube for guiding an operating wire at the extended end, and also provides a support for an outer tube that guides an operating wire on one side of the bracket. A sumo frame with two pulleys is supported via a pair of links, while one of the links is extended to the other side of the bracket, and a fixing device for the operating wire is provided at this extended end. It is characterized by:

Embodiments of the transmission according to the present invention will be described below based on the drawings.

Reference numeral 1 designates a bracket 1 to be fixed to a stationary member 2 of a bicycle frame, etc., and is made of a single plate, and one end thereof is provided with a fixing part 1a that is fixed to a hawk end 2a of the stationary member 2 together with a bubble shaft. The other end of the bracket 1 is extended toward the front side of the bicycle along the chain stay 2b of the stationary member 2, and this extended portion 1b
A support 3 that supports the end of the outer tube O that guides the operating wire W at the bent portion 1C by bending the tip sideward.
It is installed.

Further, in the middle of the bracket 1, there are provided a pair of support pieces 1d and le that protrude to one side.
One ends of the pair of links 4 and 5 are pivotally connected by two pins 6.7.

The links 5, 4 are parallel and have two first . A sumo frame 8 having a second pulley 81, 82 is pivotally connected to the bracket 1, a pair of links 4, 5, and the sumo frame by two pins 9, 10 parallel to the pins 6, 7. 8 constitutes a pantograph mechanism.

Further, one end of the link 4 is extended to the other side of the bracket 1, and the operating wire W is connected to the extended end 4a.
Attach a fixture 11 that fixes the end of the
The support 3 is placed closer to the front of the bicycle.

Then, the outer tube O supported by the support 3 can be stretched along the chain stay 2b of the stationary member 2, and is not bent greatly near the support 3.

Also, the above-mentioned link 4 is provided with abutments 4b and 4C, and the tips of the adjustment screws 12 and 13 attached to the bracket 1 are engaged with the abutments 4b and 4C, so that the adjustment screws 12 The swing range of the links 4 and 5 is adjusted by .13.

The extension portion 4a is made to protrude from a notch hole 1f provided in the middle of the bracket 1 to the other side of the bracket 1.

Further, the sumo frame 8 is composed of a set of two plates, and the first... The second pulley 81.82 is connected to the first pulley. It is rotatably supported via the second horizontal plate 83 and 84.

A bearing metal 85 is interposed between the first horizontal shaft 83 and the first pulley 81, and a tension spring 86 is provided between the bearing metal 85 and the first horizontal shaft 83. 86 urges the sumo frame 8 with respect to the first horizontal shaft 83 in the tensioning direction of the driving chino.

Further, at one end of the first horizontal shaft 83, the supporting pieces 1d and le
A movable member 87 having a pair of support pieces 87 a , 87 b parallel to the above is attached, and the support pieces 87 a , 87 b of this movable member 87 are connected to the link 4 via the pins 9 , 10 . , 5.

In the figure, 14 is a return spring wound around the pin 10, and 15 is a stopper for regulating the range of swing of the sumo frame 8.

In the above configuration, the operation wire W is connected to the fixture 11.
It is used with the outer tube O supported on the support 3, and when the operation wire W is pulled by operating a control lever (not shown), the space between the fixation 11 and the support 3 is used. The distance between the pantographs is shortened, the pantograph mechanism is deformed, and the sumo frame 8 is displaced in the axial direction of a multi-stage sprocket (not shown).

And the first one above. The drive chino guided by the second pulley 81, 82 is replaced with one of the sprockets, and as the chino is replaced, the sumo frame 8 is rotated by the tension spring 86 to rotate the first horizontal shaft 83. It swings in the center to give a certain tension to the cheno.

Since the support 3 is disposed on the front side of the bicycle with respect to the fixture 11 as shown in FIGS. 1 and 2, the outer tube O can be stretched along the chain stay 2b of the stationary member 2. Moreover, this outer tube O does not curve greatly near the support 3.

As described above, the present invention extends a bracket fixed to a stationary member of the bicycle toward the front side of the bicycle, provides a support for the outer tube at the extended end, supports a pair of links on the bracket, and supports the outer tube. Since one of the links is extended to provide a fixing device for the operating wire, and the supporting device is placed on the front side of the bicycle from the fixing device, the outer tube can be moved along the chain stay of the stationary member of the bicycle. It can be stretched, and the outer tube does not curve significantly near the support.

Therefore, there is no problem of getting one's feet caught on the outer tube, and the frictional resistance during relative movement between the outer tube and the operating wire can be reduced, and the efficiency of transmitting the operating force by the operating lever can be improved.

Furthermore, the present invention utilizes a bracket, which is provided with the support and supports the sumo frame via a pair of links, making the structure simple, lightweight, and inexpensive.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a front view;
FIG. 2 is a partially cutaway plan view, FIG. 3 is a perspective view of the bracket, and FIG. 4 is a perspective view of the link. 1... Bracket I, 2... Stationary member, 3... Support tool, 4.5... Link,
8...Sumo frame, 81.82...Pulley, 11...Fixing tool, W...Operation wire, O...Outer tube .

Claims (1)

[Scope of utility model registration request] A bracket to be fixed to a stationary member of a bicycle is extended toward the front side of the bicycle, and a support for an outer tube for guiding an operating wire is provided at the extended end, and a pair of links are provided on one side of the bracket. , a bicycle supporting a sumo frame having two pulleys, one of the links extending to the other side of the bracket, and a fixing device for the operating wire being provided at the extended end. Exterior transmission.