JPH0226790Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an improvement of a side-pull type caliper brake for a bicycle.

<Prior Art> Generally, in a side-pull type caliper brake for a bicycle, a pair of front and rear overlapping brake arms 2 and 3 are attached to a center bolt 4 as shown in Figure 5.
A support body 18 is fitted on the rear end side of the center bolt 4 so as to be swingable, and a support body 18 is fitted on the rear end side of the center bolt 4 so that it cannot move in the axial direction.
A support nut 22 is screwed into the male threaded portion 20 on the front end side, and both the brake arms 2 and 3 are held in a sandwich shape by the support body 18 and the support nut 22, and are prevented from coming off from the center bolt 4. There is. In this case, the support nut 22 cannot be pressed by the front brake arm 2 because the brake arms 2 and 3 need to be swingable. Therefore, it has been conventional practice to interpose a lock nut 26 between the support nut 22 and the front brake arm 2 to prevent the support nut 22 from loosening.

<Problem to be solved by the invention> When the lock nut 26 is interposed as described above, the support nut 22 is removed by the thickness of the lock nut 26.
has the disadvantage that it protrudes forward and increases the packaging volume.

In addition, if the center bolt 4 is to be used in common with the brake 1 having brake arms 2 and 3 with different wall thicknesses, the male threaded portion 20 at the front end of the center bolt 4
It is necessary to make it long in the axial direction to some extent. Then, if the brake arms 2 and 3 are thin, at least the front brake arm 2
is supported by the male threaded portion 20 of the center bolt 4. Then, since the male threaded portion 20 is loosely fitted to the brake arm 2 so as not to crush the threads thereof, there was a problem in that the brake arm 2 swings loosely.

In view of the above, an object of the present invention is to provide a side-pull type caliper brake for a bicycle that can prevent a support nut from loosening without using a lock nut, and can also prevent rattling of the brake arm. .

<Means for Solving the Problems> The technical measures taken by the present invention to solve the problems of the prior art are characterized by the fact that the pair of front and rear overlapping brake arms 2 and 3 are connected to the center bolt 4.
A support body 18 is fitted on the rear end side of the center bolt 4 so as to be swingable, and a support body 18 is fitted on the rear end side of the center bolt 4 so that it cannot move in the axial direction.
A support nut 22 is screwed into the male threaded portion 20 on the front end side, and both the brake arms 2 and 3 are held in a sandwich shape by the support body 18 and the support nut 22, and are prevented from coming off from the center bolt 4. In the bicycle side-pull caliper brake 1, the female screw hole 23 of the support nut 22 is a through hole, and the depth of the female screw hole 23 is such that the front end surface of the center bolt 4 reaches only a halfway position in the axial direction. The locking bolt 24, which presses against the front end surface of the center bolt 4, is screwed into the female threaded hole 23, and the support nut 22 is attached to the front brake arm 2 or the front and rear brake arms 2, 3 so as to be relatively rotatable and tightly attached. The point is that they are fitted in a shape.

<Operation> When the locking bolt 24 is screwed into the female threaded hole 23 and brought into pressure contact with the front end surface of the center bolt 4, a force is applied to separate the center bolt 4 and the support nut 22 in the direction of separation, so that the support nut 22 It can be used to prevent loosening.

Since the support nut 22 is fitted to the front brake arm 2 or the front and rear brake arms 2 and 3,
There is no need to support the brake arms 2 and 3 by the male threaded portion 20 at the front end of the center bolt 4, and since the brake arms 2 and 3 are relatively rotatable and closely fitted, no wobbling occurs in the swinging of the brake arms.

<Example> Hereinafter, an example of the present invention will be described based on the drawings.

1 and 2 show a side-pull type caliper brake 1 for a bicycle, and 2 and 3 are a pair of front and rear brake arms, which are externally fitted onto a center bolt 4 so as to be swingable. Note that a washer 5 is interposed between both brake arms 2 and 3.

The front brake arm 2 has a C-shape, and a brake shoe 6 is attached to the lower end.

The rear brake arm 3 has a Y-shape with a protruding arm 7 protruding from the middle, and a brake shoe 8 is attached to the lower end.

A brake spring 9 has one end engaged with a protrusion 10 on the front brake arm 2 and the other end engaged with a protrusion 11 on the rear brake arm 3, and urges both brake arms 2 and 3 in a direction to widen the gap between their lower ends. ing.

11 is a Bowden wire, one end of an outer wire 12 is received by the protruding arm 7, and an inner wire 13
One end is attached to the tip of the front arm 2 via a well-known quick release device 14. The other end of the Bowden wire 11 is connected to a well-known brake lever device (not shown). This results in
When the brake lever is rotated, the inner wire 13 moves in the axial direction within the outer wire 12, and as the distance between the tip of the protruding arm 7 and the tip of the front brake arm 2 expands or contracts, the front and rear brake arms 2 and 3 are moved to the center bolt. The brake shoes 6 and 8 move toward and away from the rim 16 of the tire 15.

The rear end of the center bolt 4 is attached to the bicycle body (not shown), and a support body 18 is fitted onto the rear end side through a washer 17 so that it cannot move in the axial direction, and is attached to the rear end surface of the rear brake arm 3. It is in contact. In order to prevent the brake spring 9 from coming off, the support body 18 has a groove 19 formed in its front end surface into which the brake spring 9 is inserted.

In addition, a male threaded portion 2 is provided at the front end of the center bolt 4.
0 is formed, and a support nut 22 is screwed into this via a washer 21, and is in contact with the front surface of the front brake arm 2. As a result, both brake arms 2 and 3 are held in a pinched manner by the support body 18 and the support nut 22, and are prevented from coming off from the center bolt 4.

Here, the female screw hole 23 of the support nut 22 is a through hole, and the depth of the female screw hole 23 is such that the front end surface of the center bolt 4 reaches only a halfway position in the axial direction. A locking bolt 24 that presses against the front end surface of the center bolt 4 is screwed into the female threaded hole 23. As shown in the third figure, the locking bolt 24 has a hexagonal hole 25 for inserting a tool in the center thereof. As a result, the support nut 22 is first screwed onto the center bolt 4, and brought into contact with the front surface of the front brake arm 2 to the extent that both brake arms 2, 3 can swing. Next, by screwing the locking bolt 24 into the female screw hole 23 and pressing it against the front end surface of the center bolt 4, a force is generated that separates the center bolt 4 and the support nut 22 in the direction of separation. It is prevented from loosening.

Further, the shape of the support nut 22 is such that the front end portion 22a
has a truncated cone shape, the middle part 22b has a hexagonal column shape for tool engagement, and the rear end part 22c has a cylindrical shape with a smaller diameter than the middle part 22b. The rear end 22c of this support nut 22 is attached to the front brake arm 2.
The middle part 2 is fitted tightly and relatively rotatably to the
The rear surface of 2b is used to clamp the front and rear brake arms 2 and 3.

Side-pull caliper brake 1 with the above configuration
According to the above, since the support nut 22 is prevented from loosening by the locking bolt 24 screwed into the female screw hole 23, there is no need for the lock nut 26 screwed to the center bolt 4 as in the conventional case. It can be made more compact by the thickness of 26 mm.

Further, since the rear end portion 22c of the support nut 22 is relatively rotatably and tightly fitted to the front brake arm 2, there is no need to support the brake arm 2 by the male threaded portion 20 at the front end of the center bolt 4. There is no wobbling in the swinging of the brake arm 2.

FIG. 4 shows a different embodiment, and the difference from the above embodiment is that there is a recess 2 on the front surface of the front brake arm 2.
7, and the support nut 22 is embedded in the recess 27 to achieve further compactness, and the rear end 22c of the support nut 22 is connected not only to the front brake arm 2 but also to the rear brake arm 3. They are relatively rotatable and closely fitted. With this, the same effects as those of the above-mentioned embodiment can be obtained, and the device can be made more compact.

<Effects of the invention> According to the side-pull caliper brake according to the invention, the female threaded hole of the support nut is a through hole, and the depth of the female threaded hole is such that the front end surface of the center bolt reaches only a midway position in the axial direction. Not deep and
A locking bolt that presses against the front end surface of the center bolt is screwed into a female threaded hole, and a support nut is tightly and rotatably fitted to the front brake arm or the front and rear brake arms.
As a result, the lock nut is not used to prevent the support nut from loosening, as is the case in the past, so the size can be reduced by the thickness of the lock nut. Further, since there is no need to support the brake arm with the male threaded portion at the front end of the center bolt, there is no wobbling in the swinging of the brake arm.

[Brief explanation of drawings]

Fig. 1 is a cutaway plan view of essential parts of a side-pull caliper brake according to an embodiment of the present invention, Fig. 2 is a front view of the same, Fig. 3 is a perspective view of the same locking bolt, and Fig. 4 is a different implementation. FIG. 5 is a fragmentary plan view of the main part according to the conventional example. 1...Brake, 2...Front brake arm,
3... Rear brake arm, 4... Center bolt, 18... Support body, 20... Male threaded part, 22...
...Support nut, 23...Female screw hole, 24...Loosening bolt.

Claims (1)

[Scope of utility model registration request] A pair of front and rear overlapping brake arms 2 and 3 are fitted around the center bolt 4 so as to be able to swing freely, and a support body 18 is fitted onto the rear end of the center bolt 4 so as not to be able to move in the axial direction. A support nut 22 is screwed into the threaded portion 20, and the support body 18 and the support nut 2
A bicycle side-pull type caliper brake 1 in which both brake arms 2 and 3 are shaped like a clamp and prevented from coming off from a center bolt 4.
The female screw hole 23 of the support nut 22 is a through hole, and the depth of the female screw hole 23 is such that the front end surface of the center bolt 4 reaches only a halfway position in the axial direction. The locking bolt 24 that presses against the locking bolt 24 is screwed into the female threaded hole 23, and the support nut 22 is fitted tightly and relatively rotatably to the front brake arm 2 or the front and rear brake arms 2, 3. Features a side-pull caliper brake for bicycles.