JPS6246399B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bicycle brake, and more particularly to a pivot arm having a brake shaft at its tip.

In general, a side-pull type brake has curved rotating arms 2 and 3 that are each pivotally connected to a single center bolt shaft 1, as shown in FIG. By applying force to 3, both arms 2 and 3 are rotated in a direction toward each other, and a brake shoe 5 fixed to the tip thereof is pressed against a rim 6 of a bicycle tire, thereby performing braking. When the brake shoe 5 is pressed against the rim 6, stress is naturally applied to both arms 2 and 3 in the direction of rotation of the bicycle tire 7. Here, if both arms 2 and 3 are made of iron or forged light alloy, both arms 2 and 3 can sufficiently withstand this stress, but if both arms 2 and 3 are made of synthetic resin molded products or die-cast If the arms 2 and 3 are made of high quality materials, they may not be able to withstand the stress and may break. In particular, the area near the axis 1 where stress is concentrated may break or crack. This tendency becomes more pronounced when the hardness of the synthetic resin decreases over time due to long-term use.

Therefore, we made the entire area near the axis of arms 2 and 3 thicker,
Measures are taken to increase the mechanical strength, but if the entire area near the axis is made thicker in this way, both arms 2 and 3 will overlap each other,
Since it is pivotally connected to a shaft 1 that passes through both, the thickness of the entire brake in the axial direction increases significantly, which causes inconvenience when mounted on a bicycle and reduces marketability. Therefore, the above-mentioned drawback can be overcome by pivoting the pair of arms in parallel using two axes without overlapping them. Conventionally, a bicycle brake device disclosed in Japanese Patent Application Laid-open No. 14638/1983 is known as having a structure in which the arms are pivoted on two axes. According to this, the inner and outer arms are pivoted on the mounting bracket on two axes, and the outer arm The upper part of the outer arm is extended laterally and connected to the inner wire, and an upwardly facing engagement surface is formed in the middle part of the outer arm, and a downwardly facing engagement surface is formed at the corresponding part of the inner arm and slidably overlaps with the above engagement surface. It consists of a structure provided with an engaging surface.

However, in the above configuration, since the main focus is on interlocking the arms, no consideration is given to the wall thickness, which is a problem when molding the arms from synthetic resin, and the inner arm is always thinner than the outer arm (approximately half the thickness). ) Since it is set to be thick, it is not possible to increase the strength of the arm, and since it is assumed that the engagement surface is engaged from the front and back (in the axial direction), it is impossible to construct a structure in which the main parts of the arm are not overlapped. ing.

Furthermore, the inner arm performs braking motion only in conjunction with the outer arm via the engagement surface, and there is a drawback that it will not operate if the engagement surface is destroyed or damaged.

Next, in the center-pull type caliper brake according to Utility Model Publication No. 53-15097, a configuration is disclosed in which a separate locking body is pivotally attached to the arm and the locking body is hooked to the middle part of the wire. However, in this case, although the brake arms are pivotally attached to the fixed arm on two axes, the brake arms are overlapped with each other, and no means is provided to suppress the increase in thickness in the axial direction. In addition, Japanese Utility Model Publication No. 53-24765 discloses a configuration in which gears are meshed to prevent one-sided braking, and the large arch and small arch are pivoted to the flanges of the mounting bolts in parallel. ,
In this case, the large arch overlaps the front surface of the small arch and extends to the opposite side to be connected to the inner wire, so it is necessary to curve the large arch and reduce the axial thickness at the part where it overlaps with the small arch. increase

In the rim brake of Special Publication No. 38-16361, a cam is used to prevent the lever from working on one side, but in this case, the structure is complicated, and the pivot part of the lever is made thicker and made of plastic material. It is difficult to use.

An object of the present invention is to rotate at least a pair of main arms without overlapping each other, thereby reducing the space occupied by the main arms in the axial direction as much as possible, and making it possible to make the brake arms made of resin. Each one is independently linked to the brake wire. This will be explained in detail below using examples.

FIG. 2 is a principle diagram showing an embodiment of the bicycle brake according to the present invention, and is a diagram corresponding to the conventional side-pull type brake shown in FIG. This is a flat base that is fixed to the vehicle body.
It has two shafts 9 and 10 on the right, and the ends of curved arms 11 and 12 are independently rotatably pivoted to each shaft. A brake shoe 15 facing a rim 14 of a bicycle tire 13 is fixed to the tip of each arm 11, 12. Axis 9 of arm 11
From the side, the actuating arm 16 integrated with this arm 11
extends and a link 18 is provided at the end of the actuating arm 16.
is pivotally connected around a shaft 19, and an inner wire 21 of a brake wire 20 is connected to the other end of the link 18. Further, an actuation arm 17 integral with the arm 12 protrudes from near the shaft 10 of the arm 12 on the side close to the brake wire 20, and the tip of the actuation arm 17 is connected to the outer wire 22. In addition,
One end of a rod 23 for spacing setting is pivotally connected to the shaft 10, and the other end of the rod 23 is connected to one end of the link 18 by a shaft 24.
It is pivoted at. In this case, the length of the actuation arm 16
l ₁ , the length l ₂ of the rod 23, and the outer wire 22
The distance _l3 between the tip and the shaft 10 is set to be equal in length.

Therefore, according to the above configuration, when the inner wire 21 is pulled in the direction of the arrow 25 by operating a lever (not shown) fixed to the bicycle handlebar, the link 18 is pushed up in the same direction, and the operating arm 16 is thereby kept constant. The arm 11, which is integral with the operating arm 16, also rotates inward about the shaft 9 as a fulcrum. In addition, outer wire 2
2 also moves in a direction 26 opposite to that of the inner wire 21 due to the reaction caused by the movement of the inner wire 21, thereby pushing down the actuating arm 17. For this reason,
The arm 12 integrated with this operating arm 17 is a shaft 10.
Rotates inward using the brake shoe 1 as a fulcrum.
5 are each pressed against the rim 14 and provide a constant braking force. Next, when the force applied to the brake lever (not shown) is released, both arms 11, 12 are rotated outward by the force of a spring (not shown) and restored. According to this embodiment, since the link 18 is connected to the shaft 10 by the rod 23, the distance from the shaft 10 is always maintained by the length _l2 of the rod 23, and the force of the inner wire 21 is actuated. The information can be reliably transmitted to the arm 16. Furthermore, since the lengths l ₁ and l ₂ of the actuating arm 16 and the rod body 23 and the interval l ₃ are set to equal values, the amount of rotation of the arms 11 and 12 can always be kept constant, and each brake system You 15
The pressing force against the rim 14 can be made equal.

According to the embodiment described above, the shafts are substantially separated into those for arm 11 and those for arm 12, and the arms are prevented from overlapping each other at the shaft portions as in the conventional case, so that the shafts are located near the shafts of each arm. Even if the thickness of the arm is increased, the size in the axial direction near the shaft can be made smaller than in the past, and the arm can be made of synthetic resin to increase its mechanical strength. Further, as another effect, the distance between the brake shoe 15 and the shafts 9, 10 can be made shorter than in the conventional case. This means that if the same amount of force as before is applied to the brake lever based on the lever principle, the pressing force of the brake shoe 15 can be made larger than before, or even if a smaller force than before is applied to the brake lever. It is possible to apply the same pressing force as before. Therefore, a brake having such a structure is also suitable for use by children and women who require a small gripping force.

FIG. 3 is an exploded perspective view of a bicycle brake according to the present invention embodying the principle explained in FIG.
5 and 6 are a front view, a side view, and a plan view thereof, and the same parts as in FIG. 2 are given the same reference numerals. In this case, a center bolt 27 for mounting the bicycle body is fixed to the base 8, and the left side of the base 8,
On the right side, a screw hole 28 into which bolts corresponding to the shafts 9 and 10 are screwed is provided. Each bolt penetrates through hole 29 of arm 11, 12, respectively, and holds arm 11, 12 rotatably. Each arm 1
A movement adjustment slit 35 for fixing the brake shoe 15 is provided at the tip of each arm 11, 12, and the operating arms 16, 17 described in FIG. 2 protrude from each arm 11, 12. The link 18 and the rod 23 are fixed to each other by bolts 30 on both sides, and the inner wire 21 is inserted into the hole 31 of the bolt 30 and tightened. 32 is arm 1
It is a spring that rotates 1 and 12 outward,
This is fitted into the groove 33 of the base body 8, and its both ends are fitted into the inner grooves 34 of the arms 11 and 12. Here, the arms 11 and 12 are manufactured by injection molding resin, and depending on the case, the link 18 and the rod body 23 are also manufactured by a similar method. In this way, by manufacturing the main parts of the brake by injection molding, mass productivity can be improved, costs can be lowered, and it goes without saying that the weight can be further reduced.

FIG. 7 is a front view showing another embodiment of the bicycle brake according to the present invention, and the same parts as in FIG. 2 are designated by the same reference numerals. In this case, the link 18 in FIG.
It is designed to be able to slide freely against the surface. Therefore, when the inner wire 21 rises now, the rod 23 moves toward the shaft 1.
0 as a fulcrum, and the actuating arm 16 in contact with the rod 23 rotates around the shaft 9 as a fulcrum, thereby causing the arm 11 to rotate inward and press the brake shoe 15 against the rim 14. Further, when the outer wire 22 descends due to the reaction of the inner wire 21, the actuating arm 17 rotates about the shaft 10, moves the arm 12, and moves the brake shoe 15.
is pressed against the rim 14. That is, even if the link 18 is omitted as described above, the same operation as in the case of FIG. 2 can be performed.

As explained above, according to the bicycle brake according to the present invention, there is a bicycle brake having a brake shoe at the tip.
Each of the main arms is pivotally connected to two shafts spaced apart by a certain distance, and the main arm is provided with an operating arm so that the main arm can rotate via this operating arm. Overlapping can be prevented, and for this reason, even if the outer diameter of the main arm is increased, the overall wall thickness in the axial direction can be made smaller than in the past, and for this reason, at least the main arm can be made of synthetic resin, making mass production possible. Cost reduction can be achieved. In particular, since the rod is coaxially pivoted with one main arm and connected to the inner wire, the traction force of the inner wire is converted into rotational force, and this rotational force is further transferred to the other operating arm, which is connected via a link. It can be transmitted via the link if the other actuating arm is in contact with the rod, or directly to the other actuating arm if it abuts on the rod. This eliminates the need to connect the other actuating arm directly to the inner wire, and allows the left and right main arms to be attached to the base without any overlap between the pivot joint and the brake shoe. Can be set to . In addition, since the other operating arm extending from the other main arm has a short length so that it is not directly connected to the inner wire, it also has the function of preventing one side effect. In addition, since the distance from the main arm pivot to the brake shoe can be shortened, force can be effectively transmitted from the brake lever to the brake shoe, reducing fatigue on the driver's fingers.

[Brief explanation of the drawing]

Fig. 1 is a principle diagram showing an example of a conventional bicycle brake, Fig. 2 is a principle diagram showing an embodiment of the bicycle brake according to the present invention, and Fig. 3 is a perspective view specifically showing the bicycle brake according to the present invention. ,Figure 4,
5 and 6 are a front view, a side view, and a perspective view, and FIG. 7 is a front view showing another embodiment of the bicycle brake according to the present invention. 8... Base body, 9, 10... Shaft, 11, 12...
Arm, 16, 17... Operating arm, 15... Brake shoe, 18... Link, 20... Brake wire, 33... Groove, 32... Spring.

Claims (1)

[Scope of Claims] 1. A pair of opposing left and right main arms each having a brake shoe at the tip are pivotally connected to two shafts spaced apart by a certain distance, and an actuation arm is provided on the main arm, and In a side-pull type bicycle brake in which the main arm rotates with A pair of left and right main arms that are individually pivoted to the base body without overlapping and rotate in the same plane, and an outer wire that extends integrally from one main arm (on the brake wire installation side) to the brake wire installation side. one operating arm that is operatively connected; a rod that is coaxially connected to the axis of the one main arm and operatively connected to the inner wire; 1. A bicycle characterized by comprising: a main arm extending in series from the main arm (on the separation side), and the other operating arm abutting or interlockingly connected via a link to the above-mentioned rod so as to interlock with the rotation thereof. Brake for. 2. The bicycle brake according to claim 1, wherein a groove is provided in the base body, and a spring for rotating the main arm outward is fitted into the groove and held.