JPH055715B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a bicycle caliper brake, and more particularly to one that has been improved to include a built-in return spring.

[Conventional technology]

The conventional general structure of this type of bicycle caliper brake is shown in JIS D 9414. First, the structure of this conventional caliper brake will be explained with reference to FIG. A pair of left and right brake arms 2 and 3 extend across the wheel rim to a support shaft 1 that is fixed to the hawk crown in the case of the front brake, and to a horizontal bar that spans the top of the back hawk in the case of the rear brake. Supported in a swingable manner. Brake shoes 7, 8 are attached to the inner sides of the ends of the brake arms 2, 3, which are brought into pressure contact with the side surfaces of the rim to perform braking operations. The inner cable w1 of the operation cable W is located on the opposite side of the support shaft 1 from the end brake shoe attachment part of the left arm 2.
An actuating arm 4 for fixing the outer cable w2 of the operating cable W is also provided at an appropriate part of the right arm 3, and an actuating arm 5 for fixing the outer cable w2 of the operating cable W
are provided respectively. Further, the left and right arms 2 and 3 are always biased by a return spring 6 in a direction in which their tips are separated from each other, that is, in a direction in which the brake is released. This return spring 6 has a central portion 6a fixed to a support shaft 1, and both tip portions 6b and 6c of the wire spring 6 are directed outward toward protrusions formed at appropriate positions near the tips of the left and right arms 2 and 3, respectively. It is constructed by hooking it to. Therefore, when a brake operating lever (not shown) is operated, the inner cable w1 of the operating cable W is pulled, and the operating arms 4 and 5 of the left and right arms 2 and 3 are moved closer to each other. As a result, the tips of the left and right arms 2, 3 are forced to approach each other, and the brake shoes 7, 8 of the respective arms 2, 3 are pressed against the side surface of the rim of the rotating wheel, thereby performing a braking action. When the operating force of a brake operating lever (not shown) is relaxed, the left and right arms 2, 3 are separated from each other by the elasticity of the return spring 6, and the braking action is released.

[Problem to be solved by the invention]

However, in the above-mentioned general bicycle caliper brake, the return spring 6, which is usually made of spring steel, is mounted in an exposed manner to the outside, which causes various problems. In other words, the use of light alloys for brake arms and other accessories has recently progressed, and the problem of rust is disappearing, but return springs have to be made of steel materials such as spring steel, which are prone to rust, and raindrops can cause this damage. Rust occurs on the return spring.
When such rust occurs, it not only looks bad, but also makes it difficult for the spring to slide against the protrusion of the arm on which the tip of the spring is to be hooked, resulting in very poor return of the arm.
If the arm returns poorly, the brakes will be applied slightly even though the brake control lever is not operated, resulting in a large loss. Furthermore, the fact that the return spring 6 is exposed to the outside as described above puts a limit on the improvement of the appearance of the caliper brake itself. In other words, even if the external shape is set to minimize the unevenness of the outer surface in order to improve aerodynamic characteristics, the return spring is exposed, so this return spring affects the entire caliper brake. This results in the formation of unevenness on the outer surface. Therefore, the problem to be solved by the present invention is to eliminate all at once the problems caused by the return spring being exposed to the outside in the conventional bicycle caliper brake.

[Means to solve the problem]

In order to solve the above problems, the bicycle caliper brake of the present invention takes the following technical measures. That is, the boss portion formed at the appropriate portion of the first brake arm and the boss portion formed at the appropriate portion of the second brake arm are fitted so as to be axially one behind the other with respect to the support shaft, and the first brake arm and In a bicycle caliper brake configured such that the second brake arm can swing around a support shaft, a predetermined length in the axial direction of the boss portion of the first brake arm on the side adjacent to the second brake arm. A first annular space is formed by enlarging the inner diameter of the second brake arm, and a second annular space is formed by enlarging the inner diameter of a predetermined length in the axial direction adjacent to the first brake arm of the boss portion of the second brake arm. A first torsion spring is fitted into the first annular space, one end of the first torsion spring is substantially received by the first brake arm, the other end is substantially received by the support shaft, and a second torsion spring is fitted into the second annular space. A torsion spring is fitted in the second torsion spring, and one end of the second torsion spring is substantially received by the second brake arm, and the other end is substantially received by the support shaft, and the second torsion spring is provided on one of the first brake arm and the second brake arm. The brake arm is characterized in that the maximum expansion state of both brake arms is defined by the engagement of the tip of the stopper screw screwed onto the other end with the engagement portion. To further summarize this invention, a torsion spring is used as a return spring that always elastically biases the first brake arm and the second brake arm in a direction in which their tips move away from each other, and this is used to oscillate the respective arms. After loading the torsion spring into the internal annular space of the boss portion formed in the dynamic support portion in a natural state, the first brake arm and the second brake arm are mutually rotated in a direction to squeeze each of the torsion springs. In the state that
By simply engaging the tip of the stopper screw screwed into the other brake arm with the engagement part provided on one brake arm, the maximum expansion state can be achieved with both brake arms biased in the brake release direction. This allows them to be assembled as specified.

[Effect]

The first torsion spring fitted into the first annular space of the boss portion of the first brake arm is substantially received by the first brake arm at one end and by the support shaft at the other end. Therefore, the first brake arm is always given a tendency to elastically rotate in one direction with respect to the supporting shaft as a fixed body. On the other hand, the second torsion spring fitted into the second annular space of the boss part of the second brake arm also has one end connected to the second brake arm and the other end connected to the support shaft.
Each is practically accepted. Therefore, the second brake arm always has a tendency to elastically rotate in one direction with respect to the supporting shaft as a fixed body. Of course, the direction in which the first brake arm tries to rotate elastically and the direction in which the second brake arm tries to rotate elastically are opposite, and the tip of the first brake arm and the second brake arm The tips are separated from each other. Thus, in the present invention, the torsion springs fitted into the boss portion of the first brake arm and the boss portion of the second brake arm perform the same function as a conventional exposed return spring.

【effect】

However, since the torsion spring is incorporated inside the boss portion, it is not visible from the outside and does not come into direct contact with raindrops. Moreover, since the annular space can be filled with a rust preventive material such as grease, even if some raindrops enter the annular space, the torsion spring will not easily rust. There isn't. moreover,
In the present invention, there are substantially two
A number of springs are used, and each arm receives a separate biasing force based on the support shaft. From this, for example, even if the distance from the spindle of the cable attachment part to the actuating arm of each arm is different for each arm,
By making the elasticities of the two springs substantially different from each other, it is possible to equalize the rotation moment to be applied to each arm. Therefore, the degree of freedom in arranging the cable increases, and countermeasures against cable breakage become easier. After the torsion springs are assembled in their natural state, the arms are mutually rotated in the direction of squeezing the torsion springs (in other words, the braking direction), and the engaging portion provided on one arm is connected to the other arm. The simple operation of engaging the tip of the stopper screw screwed into the
The assembly can be completed so that both brake arms are mutually biased in the brake release direction and the maximum expansion state is defined. From the above, the bicycle caliper brake of the present invention completely eliminates the problems of conventional caliper brakes in which the return spring is exposed to the outside, namely, the problems of poor appearance due to rust on the return spring and deterioration of brake return. This not only solves the problem, but also provides excellent additional effects such as reducing the possibility of so-called chipping and making the overall appearance of the brake device neat and sleek. Furthermore, regarding the fact that the appearance of the brake device as a whole becomes sleek and sleek, the bicycle caliper brake of the present invention has a caliper brake that is exposed to the outside in the conventional example, as described above. In addition to the fact that the return spring is all built into the boss part of the brake arm, the engaging part for defining the maximum expansion state of both arms and the stopper screw for engaging this engaging part are also built into the boss part of both arms. Since it is formed on the opposing part, it is not noticeable from the outside, and as mentioned above, the final assembly can be easily performed, and even the means for specifying the maximum expansion state can be applied to the entire brake system. There is no adverse effect on the appearance of the product.

[Explanation of Examples]

Hereinafter, embodiments of the bicycle caliper brake of the present invention will be specifically described with reference to the drawings. FIG. 1 shows the appearance of an example of a bicycle caliper brake according to the present invention. A pair of left and right brake arms 14 and 15 each having brake shoes 12 and 13 at their tips are swingably supported on the support shaft 11, and an operation cable W is connected to the actuation arm 16 of the first brake arm 14. inner cable w1
However, the outer cable w2 of the operating cable W is connected to the operating arm 17 of the second brake arm 15, and when the brake operating lever (not shown) is operated, the inner cable w1 is pulled and the operating arms 16 and 17 are forced to each other. This is similar to the conventional example shown in FIG. 7 in that the brake arms 14 and 15 are moved closer together, thereby swinging the brake arms 14 and 15 so that their tips approach each other. The support shaft 11 includes a head 111, a shaft support 112 following this, and a first threaded portion 113 following this.
and a second threaded portion 11 following this first threaded portion.
A special bolt with 4 is used. The shaft support 112 rotatably fits into and supports the inner holes 18a and 19a of the boss portions (first boss portion 18, second boss portion 19) of the first brake arm 14 and the second brake arm 15. A lock nut 20 consisting of two nuts 20a and 20b is tightened on the first threaded portion 113, so that the first boss portion 18 and the second boss portion 19 are secured to the head 111 on the support shaft 11.
and the lock nut 20. The second threaded portion 114 is for attaching the brake device itself to the bicycle frame. That is, in the case of a front brake device, this second threaded portion 11
4 is inserted into a support hole of a hawk crown (not shown), and a nut is tightened at the tip. In the case of a rear brake device, the second threaded portion 114 is inserted into a support hole formed in a rod extending between the upper portions of backhawks (not shown), and a nut is tightened at the tip. In addition, as clearly shown in FIG. 3, the support shaft 11 has an intermediate washer 21, which will be described later, fitted between the first boss part 18 and the second boss part 19 in a non-rotatable manner. An oval-shaped section 22 is formed. a first boss portion 18 of the first brake arm 14;
The second boss portion 19 of the second brake arm 15 is fitted into the shaft support 112 of the support shaft 11 so as to move back and forth in the axial direction. As shown in FIGS. 2 and 3, the diameter of the inner hole 18a of the first boss portion 18 is enlarged at an appropriate length portion 18b near the second boss portion 19, so that the shaft support 11
A first annular space 23 is formed, which is surrounded by the second outer periphery, the diameter-enlarged inner hole 18b, and the stepped portion 18c that separates the enlarged-diameter portion from the normal inner diameter portion. Further, the diameter of the inner hole 19a of the second boss portion 19 is enlarged at an appropriate length portion 19b near the first boss portion 18, so that the support shaft portion 112
A second annular space 24 is formed that is surrounded by the outer periphery, the inner hole 19b whose diameter has been enlarged, and the stepped portion 19c that separates the enlarged diameter portion and the normal inner diameter portion. A first torsion spring 25 and a second torsion spring 26 are loaded into the first annular space 23 and the second annular space 24 so as to surround the support shaft 11, respectively. Each of the first torsion spring 25 and the second torsion spring 26 has one end 25a, 26a substantially received by each brake arm 14, 15, and the other end 25b, 26b substantially received by the support shaft 11. I can accept it. In this example, one end 25a of the first torsion spring 25
is bent in the direction of the spindle, and inserted into the small hole 27 formed in the stepped portion 18c so that one end 25a is substantially received by the first brake arm 14, and the other end 25b is bent in the direction of the spindle,
This is inserted into a locking hole 28 provided in an intermediate washer 21 that is fitted between the first boss part 18 and the second boss part 19 so that it cannot rotate with respect to the support shaft 11, and this other end 25b is substantially is received by the support shaft 11. Also, in the case of the second torsion spring 26, in the same manner as the first torsion spring 25, one end 26a thereof was inserted into the small hole 29 of the stepped portion 19c of the inner hole 19a of the boss portion, and the other end 26b was provided in the intermediate washer 21. It is inserted into the locking hole 30. Note that the reference numeral 32a in the figure indicates that the tip of the first brake arm 14 and the second brake arm 15 are in contact with the engaging portion 32b provided on the first brake arm 14, and the torsion springs 25, 26 are compressed. This is a stopper screw screwed onto the second brake arm 15 so that the maximum expansion state is defined.
That is, when assembling the bicycle caliper brake of the present invention, each torsion spring 25, 26
After engaging both ends thereof with the intermediate washer 21 or a predetermined portion of each brake arm 14, 15 in a natural state, and then mutually rotating each brake arm 14, 15 in the direction of tightening each spring, The stopper screw 32a is threaded so that its tip engages with the engaging portion 32. As a result, a state in which the torsion springs 25 and 26 are compressed, that is, an assembled state is achieved in which both brake arms 14 and 15 are biased in the direction of releasing the brakes and are in their mutually maximum expanded state. be. FIG. 4 shows the main parts of another embodiment of the bicycle caliper brake of the present invention. In this example, an annular space 2 is provided in the fitting portion of each boss portion 18, 19 with respect to the support shaft.
Bushes 18d and 19d extending up to 3 and 24 are provided. In this way, the torsion springs 25, 2
Since the brake arms 6 do not come into direct contact with the support shaft 11, the brake arms 14 and 15 can swing smoothly. 5 and 6 show the main parts of another embodiment of the bicycle caliper brake of the present invention. In the above example, the torsion spring for elastically biasing the first brake arm 14 and the second brake arm 15 is
Although the first torsion spring 25 and the second torsion spring 26 are divided into two springs for the first brake arm, the torsion spring 31 of this example is a single spring with the first torsion spring 25' and the second torsion spring 26. It constitutes a spring 26'.
That is, this torsion spring 31 has a central portion with a sixth
As shown in the figure, a square shaft portion 115 is bent into a square shape, and the square portion 31a is formed as the support shaft 11.
At the same time, both ends 31b and 31c are inserted into the small holes 27 and 29 of the step parts 18c and 19c of the first boss part 18 and the second boss part 19, respectively. Therefore, with the square part 31a as a boundary, the rear part functions as the first torsion spring 25,
The front portion functions as a second torsion spring 26. As is clear from the above, in the bicycle caliper brake of the present invention, the return spring for returning the brake arm to the brake release side is
It is loaded into the boss part of each brake arm that is fitted into the support shaft. Therefore, this return spring does not rust due to raindrops, and the problems of the conventional example caused by this rust are solved at once. In addition, in the caliper brake of the present invention, a pair of brake arms are biased by substantially two springs each having one end substantially received by a support shaft. From this, the elastic return force to be applied to each arm can be made different for each arm as desired. Note that the scope of the present invention is not limited to the embodiments described above, and the present invention can be applied not only to so-called side-pull type caliper brakes as shown in the illustrated example, but also to center-pull type caliper brakes.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view of a first embodiment of the bicycle caliper brake of the present invention, FIG. 2 is an exploded perspective view of the bicycle caliper brake shown in FIG. 1, and FIG. 4 is a sectional view of the main part of the second embodiment, FIG. 5 is a sectional view of the main part of the third embodiment, and FIG. 6 is a side view of the spring used in the third embodiment. , FIG. 7 is a front view of the conventional example. 11... Support shaft, 14... (first) brake arm, 15... (second) brake arm, 18...
(First) Boss part, 19...(Second) Boss part, 23
...First annular space, 24...Second annular space, 25
...First torsion spring, 26...Second torsion spring.

Claims (1)

[Scope of Claims] 1. The boss portion formed at the appropriate portion of the first brake arm and the boss portion formed at the appropriate portion of the second brake arm are fitted so as to be axially one behind the other with respect to the support shaft, and the above-mentioned In a bicycle caliper brake configured such that a first brake arm and a second brake arm are swingable about a support shaft, the side adjacent to the second brake arm of the boss portion of the first brake arm is The first annular space is formed by enlarging the inner diameter of a predetermined length in the axial direction, and the inner diameter of the boss portion of the second brake arm adjacent to the first brake arm is enlarged. forming a second annular space, fitting a first torsion spring into the first annular space, and connecting one end of the first torsion spring to the first brake arm;
The other end is substantially received against the support shaft, and a second torsion spring is fitted into the second annular space, and one end of the second torsion spring is placed on the second brake arm, and the other end is substantially received against the support shaft. At the same time, the tip of the stopper screw threaded onto the other brake arm engages with the engaging portion provided on one of the first brake arm and the second brake arm, thereby bringing both brake arms into the maximum expanded state. A caliper brake for a bicycle, characterized in that it is configured such that: