JPS589290B2 - Side bull type caliper brake device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a bicycle caliper brake device, and more specifically, it is of a side-pull type, and is equipped with a posture correction means so that the so-called brake width between a pair of left and right brake shoes and a rim is always at an appropriate value. The present invention also relates to the provision of a new brake device which is improved so as to be able to perform a braking action at the same time even if there is an imbalance in operation transmission force that is unavoidable with Bowden cables.

A pair of brake arms equipped with brake shoes that move toward and away from the rim of the wheel are mounted on the shoulders of a handlebar post and supported by bolts, and a brake spring is provided that biases each arch in a direction away from each other. A bicycle caliper brake device in which the operating force of a lever is transmitted from one side through a Bowden cable against a brake spring is known as a so-called side-pull type brake device.

By the way, in this type of brake device, it is necessary to temporarily change the relative positional relationship between the brake arch and the rim due to wear of the brake shoes or tire puncture, and then to assemble the brake spring in the proper position. Because it was fixed on bolts, it was extremely difficult, requiring many years of experience and advanced technology, and replacing it was also a very troublesome task.

In particular, when a tire puncture occurs on a competition bicycle, it is necessary to replace the tire as soon as possible, but if the rim and brake shoe are not properly centered after the tire is replaced, a serious accident can occur. This will induce

Therefore, by fitting the brake spring holder so that it can rotate freely around a fixed axis, the brake spring itself can rotate independently without being restrained, and this can be done by operating the brake operating means in the braking direction. However, even with such a configuration, it becomes essentially meaningless if the operational transmission force of the Bowden cable consisting of the inner wire and the outer wire becomes unbalanced.

Now, if we assume that the outer wire transmits the operation transmission force more strongly than the inner wire, the second arm corresponding to the outer wire will perform a unilateral braking operation, and in this case, the brake spring will be supported to control this. Since it is not done, the other 1st arm will remain the winner, and this will cause one brake shoe to heel or cause problems with driving, and it will become virtually impossible to center each brake arm. .

The inventors have found that this tendency is particularly problematic in applications where the Bowden cable has to connect the brake lever and the braking means through a bent portion, particularly in applications for rear wheel brakes for bicycles.

In view of the above-mentioned circumstances, it is an object of the present invention to provide a brake device that automatically guarantees proper centering after operating the brake lever in the braking direction even if the centering of the rim and brake shoes is not proper. With the goal.

In addition, in this invention, the centering of the rim and brake shoe is automatically corrected by operating the brake lever in the braking direction, so assembly and disassembly work is relatively easy.
Furthermore, the present invention aims to provide a brake device that guarantees quick tire replacement.

Furthermore, another useful object of the present invention is to provide a device that guarantees automatic and proper centering even when Bowden cables are bent and connected and the transmission forces between the inner wire and the outer wire are unbalanced. shall be.

Another object of the present invention is to provide a brake device having a centering function in which a balance spring is built in and hidden after assembly so that there is no problem in appearance.

In order to achieve the above object, the present invention includes a first arm and a second arm each equipped with a brake shoe that approaches and separates from the rim of a wheel. A brake means including a brake spring biased in a direction of separation; an operation means for operating the brake means; an inner wire and an outer wire that connect the two means so that the operation means can operate the brake means. In the brake device, a spring holder for supporting the brake spring is fitted around the fixed shaft so as to be relatively rotatable about the axis of the fixed shaft, and a A friction body is fitted onto the fixed shaft, and a balance spring that resiliently biases both arms in the expansion direction is attached to the fixed shaft side, and is immovable around the shaft so that the applied force is applied to both arms. It is characterized by being made to act on.

Hereinafter, specific examples of the present invention will be described in detail with reference to the drawings.

In Figure 1.2.3 shown for the rear wheel of a bicycle, 1
is the vehicle body, specifically the bridge of the rear Hawk.

The brake device of the present invention is supported in the center of this vehicle body.

Reference numeral 2 denotes a first brake arm, which has a substantially semicircular arch shape.

Reference numeral 3 denotes a second brake arm, which has an arch shape that is approximately horseshoe-shaped.

The pair of arms 2 and 3 are supported by the vehicle body 1 with mounting bolts 4, with one end of the first brake arm 2 superimposed on the arch center portion of the second brake arm 3.

5 is a wheel tire, 6 is a tire rim, a pair of arms 2,
The arms 2 and 3 are provided with a pair of brake shoes 7 and 8 that move toward and away from the tire rim 6 when the brake shoe 3 is supported on the vehicle body by a mounting bolt 4.

The brake shoes 7, 8 are held by holders 9, 10 and are provided with bolts 1, 12 so as to be freely adjustable in the height direction as shown in the figure.
In addition, the brake width L between the brake shoe 78 and the rim 6 is approximately 2 mm.

Reference numeral 13 designates a brake spring, which is a so-called spectacle spring having a spectacle portion 14.15 at a target position centered on the mounting bolt 4, and a pin portion 16.15 formed on each arm 2, 3 at a target position.
Both free ends extend symmetrically to 17 and engage from the inside, where brake shoes 7 and 8 urge each arm 2 and 3 in a direction away from each other.

An overhanging arm 18 is formed in the middle of the first brake arm 2, and an outer receiving fitting 19 having a threaded tube 19a is loosely inserted into the free end of the arm 18, and an adjusting fitting 20 is screwed into the threaded tube 19a. equipped.

An inner wire connector 21 is provided at one end of the second brake arm 3 on the side of the overhang arm 18, and an inner wire 22 inserted into the screw tube 19a is coupled to the connector 21.
4 indicates its quick release lever.

Note that the outer wire 23 is supported by the receiving metal fitting 20,
The other end of the Bowden wire 25 consisting of the inner wire and the outer wire is connected to a brake lever (not shown),
When the operating force of the lever in the braking direction is transmitted, the pair of brake arms 23 are contracted in a direction toward each other against the brake spring 13.

As illustrated in particular detail in FIGS. 4 and 5, in the past, the brake spring holder 26 was integral with the mounting bolt 4, but in the present invention, it is fitted as a separate body so as to be relatively rotatable.

The spring holder 26 is a disk block having a bolt insertion hole 26a, and a spring holder 26b is formed in the radial direction.

The mounting bolt 4 has an axial length longer than that which passes through the vehicle body 1 when each part is attached to it, has threaded portions 4a and 4b at both ends, and has a disk-shaped receiver 27 integrally formed at the middle of the axial length. ing.

Although it is preferable to form a flat surface for tool engagement at a position corresponding to the outer circumference of the receiver 27, this is omitted in the figure.

Reference numeral 28 denotes a friction plate made of resin such as 6-nylon or a soft metal such as bronze.
and the boss portion 29 of the first brake arm 2.
It is fitted onto the top so that it can rotate freely.

Reference numeral 30 denotes a balance spring, and in the first embodiment shown in FIGS. 1 to 5, a pair of legs 30a and 30b are engaged with a spring holder 31 fitted over the back of the receiver 27 in an overhanging manner.

The spring holder 31 includes a curved portion 31a along the vehicle body 1 and a radial retaining portion 31b, and when it is fitted onto the bolt 4 and fastened to the vehicle body 1, it becomes immovable around the axis of the bolt 4. .

By engaging the arch portion 30c of the spring 30 with the holding portion 31b,
A pair of legs 30a and 30b are engaged inside each brake arm 2 and 3.

Additionally, in FIGS. 4 and 5, reference numeral 32 denotes a mounting collar, which has a curved portion 32 corresponding to the curved portion 31a of the holder 31.
The body 1 is held between the members 31 and 32, and the nut 33 is screwed onto the threaded portion 4a.

A flat washer 34 is interposed on the bolt between the spring holder 26 and the receiver 27.

35 is another flat washer, which is interposed on the bolt between the boss portions of each arm.

A flat nut 36 is screwed onto the threaded portion 4b, and has a truncated conical shape and has an engaging portion 36a for a tool formed on its opposing outer periphery.

A flat washer 37 is held between the flat nut 36 and the brake arm.

A nut 38 has a truncated conical shape, is screwed onto the threaded portion 4b, and cooperates with the flat nut 36 to enhance the design effect.

The nut 38 has a square hole in the axis of its top surface, which is filled with rubber,
A decorative body 39 made of resin is detachable.

6 and 7 show a second embodiment of the present invention, in which a rolling bearing body 40 such as a bush or a bearing is fitted onto a holder 126 for a brake spring 13 so that it can rotate freely relative to the bolt 4. A friction body 28 is interposed between the holding body 126 and the receiver 27.

Furthermore, an engaging portion 126b for the balance spring 130 is formed on the holding body 126, and the holding body 126 and the holding body 13
A balance spring 130 is wound around the bolt 4 with a resin seat plate 41 interposed between the balance spring 130 and the bolt 4.

The balance spring 130 of this second embodiment has a ring shape as shown in the eighth figure, and a pair of legs 1 30a and 130b are connected to an engaging portion 126b of a holding body 126 and an engaging portion 131 of a holding body 131.
b, and the brake spring holder 126 is engaged therewith.
Bowden cable 2 through brake spring 13 through
The unbalanced transmission force of 5 is absorbed and corrected.

Note that the legs 130a of the ring spring 130 are attached to the resin seat plate 41.
An elongated hole 41a is formed to allow the water to escape, and other parts and members common to those in the first embodiment are designated by the same reference numerals.

Further, the holding body 26 in the first embodiment also includes a rolling bearing body 4.
0 can be attached, and a rolling bearing body such as a thrust bearing or a radial ball bearing can also be attached to the boss portion of each brake arm.

In the above configuration, when one brake shoe 8 is in an unfavorable mounting position such as in contact with the tire rim 6, in order to center it in the correct position, move the brake lever (not shown) in the braking direction. When operated, the pair of brake arms 2 and 3 move in the retracting direction, and the other brake shoe 7 also comes into contact with the rim 6.

When the brake lever is released, the brake spring 13
The restoring force urges the brake arms 2 and 3 in the direction of separation, and the brake spring 13 is engaged with the holder 26 or 126, which is rotatable relative to the bolt 4, so that the brake spring 13 is evenly moved at a target position around the bolt 4. Since a restoring force acts on each of the arms 2 and 3, the arms 2 and 3 are separated from the rim 6 by a uniform width.

At this time, if the spring holder 26 or 126 were simply made relatively rotatable on the bolt 4, the holder 26 or 126 and the arms 2, 3 would rotate together and the relative positional relationship would not change. Spring holder 26 or 1
Since a friction plate 28 is interposed between 26 and the vehicle body or bolt 4 on the fixed side, the frictional force by this friction plate 28 becomes torque and causes each brake arm 23 to move toward the rim 6.
This causes the arms 2 and 3 to swing on the bolt 4.

Therefore, by repeatedly operating the brake lever in the braking direction, centering is automatically performed.

For this reason, for example, when the tire 5 is punctured and needs to be replaced, the release lever 24 is operated to release the brake shoes 7,
8 is enlarged as shown by the chain line in FIG. 5, the tire 5 is removed together with the rim 6, and a new tire is assembled together with the rim.

Thereafter, when the release lever 24 is returned to its original state, the rim 6 and the brake shoes 7, 8 may still be incorrectly centered.

Even in such a case, just by operating the brake lever in the braking direction, the rim 6 and brake shoes 7, 8 will be centered in the same way as described above, so even if a tire goes flat during a bicycle race, etc. , centering can be done easily and quickly under the appropriate brake width.

Such centering ensures perfect operation when the relative transmission forces between the outer wire 23 and the inner wire 22 of the Bowden cable 25 are balanced, but if the Bowden cable 25 is bent, for example, the push of the outer wire 23 When the pressure is greater than the pulling force of the inner wire 22,
Since the brake spring 13 is relatively rotatable on the bolt 4, proper centering may not be expected in some cases.

In such a situation, in the present invention, in both the first and second embodiments, the first brake arm 2 corresponding to the outer wire 23 first performs a braking operation, and here the fixed balance spring 30 or 130 is activated. resists and transmits spring resistance to the outer wire 23 side, thereby restricting the movement of the first brake arm 2.

On the other hand, since the inner wire 22 performs a pulling action, the second brake arm 3 performs a braking action, and as a result, the first and second arms 2, 3 synchronously perform braking while balancing each other while receiving resistance. When the brake shoes 7 and 8 come into contact with the rim 6 at an appropriate time without any time delay, and then release the operating force of the operating lever, that is, the transmission force of the Bowden cable 25, the pair of brake shoes 7 and 8 It is returned to its proper position.

The present invention is as described above, and has great practical benefits as it can effectively achieve its intended purpose.

[Brief explanation of the drawing]

FIG. 1 is a front view of a brake device according to the present invention, and FIG. 2 is a side view of FIG. 1, with tires omitted. 3 is a plan view of the brake device, FIG. 4 is an exploded perspective view of the brake device mounting section, FIG. 5 is an enlarged sectional view of the mounting section, FIG. 6 is an exploded perspective view of the second embodiment, and FIG. The figure is an enlarged sectional view during assembly, and FIGS. 8 1 and 2 are a front view and a plan view of the balance spring of the second embodiment. 1... Vehicle body, 2, 3... Brake arm, 4... Mounting bolt, 6... Rim, 7, 8... Brake. Shu, 13...
Brake spring, 26,126... Spring holder,
28...Friction plate, 30, 1 30...
...Balance spring, 31,131...30,
Holder for 130.

Claims (1)

[Claims] 1. A first arm and a second arm each having a brake shoe that approaches and separates from the rim of a wheel are each held swingably around a fixed axis, and each arm is attached in a direction away from each other. a Bowden cable comprising: a braking means provided with a biased brake spring; an operating means for operating the braking means; and an inner wire and an outer wire interconnecting both means so that the operating means can operate the braking means. and;
In the brake device, a spring holder for supporting the brake spring is fitted around the fixed shaft so as to be relatively rotatable, and a friction body is mounted on the fixed shaft between the spring holder and the brake arm. and a balance spring that elastically biases both arms in the expansion direction is attached to the fixed shaft side, and is immovable around the axis so that the applied force is applied to both arms. Type caliper brake device. 2. A holding body for the balance spring is fitted onto a fixed shaft so as to be relatively rotatable, and remains immovable when the brake means is attached to the vehicle body. A side-pull caliper brake device according to claim 1. 3. The holder for the balance spring is fitted on the fixed shaft so as to be relatively rotatable, and remains immovable when the brake means is attached to the vehicle body, and the holder for the balance spring is A side-pull type caliper brake device according to claim 1, comprising a balance spring provided on a fixed shaft.