JPS6344317Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

This invention relates to an improvement of a bicycle brake shoe structure, and particularly to a brake shoe structure that enables reliable braking with a light operating force even under humid conditions such as rainy weather.

[Conventional technology]

Under humid conditions such as rainy weather, with a normal rubber brake shoe, even with sufficient brake operation force, sufficient contact friction between the brake and the rim cannot be obtained, and the bicycle cannot be stopped safely and smoothly. Can not. Therefore, methods of improving the structure of rubber brake shoes and methods of using leather instead of rubber are known. In particular, when using leather for brake shoes, it is preferable because sufficient braking force can be obtained under humid conditions such as on rainy days, but it is very difficult to obtain thick leather that is compatible with rubber brake shoes. Have difficulty. For this reason, various configurations have been proposed in which thin leather is fitted into the rubber base material or is attached using adhesive without being fitted into the rubber base material, and all or the main part of both sides of friction with the rim are made of leather. The strong frictional force causes the thin leather to twist or peel off from the different rubber base material. This is thought to be because when a frictional force is applied, there is a difference in deformation characteristics between the leather and the rubber base material during friction, which makes it easier for the joint surfaces to separate and separate. Furthermore, for example, Japanese Utility Model Application Publication No. 54-34946 discloses a configuration in which the brake shoe is pressed by a pressure plate that moves back and forth using a tightening screw, but in the conventional shoe holder, the width of the side wall that protrudes toward the rim is narrow and Since it is inclined toward the center, it is not possible to use a large tightening screw, and it is not possible to tighten it perpendicularly to the brake shoe.

[Problem that the invention attempts to solve]

This idea was devised in view of the above circumstances, and its main problem was to securely fix the brake shoe made of laminated thin leather to the holding part with a tightening screw, and to prevent repeated braking. To provide a bicycle brake shoe structure that does not twist or peel off.

[Means to solve the problem]

In order to achieve the above-mentioned problem, this invention (a) provides a connecting piece that connects the lower end of the brake arm, which is substantially planar, from both front and rear sides, and (b) connects the lower end of the brake arm, which is approximately flat, from below. A holding part having a substantially box-shaped cross section is provided at the center, extending in the front-rear direction (parallel to the rim when assembled) and continuously protruding inward (on the rim abutting side when assembled); (c) formed inside the holding part; (a) the brake shoe is made of a laminate made of a plurality of leathers bonded vertically; and (b) the upper part of the holding part facing the A technical measure is taken in which at least one of the wall surface or the lower wall surface is set longer toward the rim, and a tightening screw is screwed into that surface in the vertical direction, and the brake shoe is pressed and fixed at the tip of the tightening screw. ing.

[Effect]

The brake shoe is fitted into the opening of the holding portion, which has a substantially box-shaped cross section, with substantially no gaps. The upper wall surface or lower wall surface of this holding portion is set long toward the rim side. Therefore, a large tightening screw can be used on the long upper or lower wall surface, and can be tightened perpendicularly to the brake shoe. This increases the adhesion force of the leather made of the laminate to the holding portion of the brake shoe. The frictional force applied to the brake shoe is evenly applied to the joint surfaces of the leathers that make up the laminate, so there is no large load applied to only one part of the leather, and the deformation caused by the frictional force is the same, so it does not twist or peel. Never.

【Example】

Hereinafter, preferred embodiments of this invention will be described based on the drawings. Bicycle brake shoe structure 1 shown in Fig. 1
is composed of a brake shoe 2 and a holding member 3. That is, the brake shoe 2 is made of thin leather 21.
It is composed of a laminate made of bonded layers and a square prism body with a tapered surface whose rim abutting surface side slopes downward and gradually becomes wider. The holding member 3 that holds this brake shoe 2 is connected to a connecting piece 6 that connects the lower end of the brake arm with the lower end of the brake arm in between, and in the front-rear direction (parallel to the rim at the time of assembly) from the bottom of the connecting piece 6 to approximately the center thereof. A holding part 5 having a substantially box-shaped cross section that continuously protrudes inward (rim abutment side during assembly) while extending in a direction (direction); and a holding part 5 formed inside the holding part 5 to fit the brake shoe 2 without a gap. It has a concave portion 4 consisting of an opening. Here, the holding portion 5 has an approximately cross-sectional shape that extends from below the connecting piece portion 6 in the front-rear direction (in the direction parallel to the rim when assembled) and continuously projects inward (on the rim abutting side during assembly) with approximately the center thereof. It has a box shape. The concave portion 4 provided in the holding portion 5 has a lower wall surface 41 on the outer circumference (of the holding portion 5) and an upper wall surface 42.
Since it extends slightly longer, it is possible to restrain and hold the brake pad P, whose rim abutting surface is formed into a tapered surface shape downwardly, with a uniform force. Further, the upper wall surface 42 and the lower wall surface 41 are connected to the holding portion 5.
The brake shoe 2 is formed so as to be substantially parallel to the brake shoe 2 fitted to the brake shoe 2. Next, the connecting piece 6 has a bracket structure in which a fitting groove 61 opens outward (in the direction opposite to the brake pad). It is formed in the shape of a step that descends to the top. Therefore, the brake arm 10 having a substantially planar shape
The lower ends of each are fitted into the fitting groove 61 from the outside. Here, the height adjustment of the bicycle brake shoe structure 1 is performed using an elongated hole 1 provided in the brake arm 10.
The length can be adjusted within a range of 1,11. Further, the protruding pieces 12, 12 formed at the lower end of each brake arm 10 are connected to the bolt hole 62 of the connecting piece part 6 and the elongated hole 11 by abutting the lower end against the stepped part 61a of the fitting hole. It is set so that it aligns with the bottom edge, so insert the washer 6 at that position.
Brake shoe adjustment can be easily performed by inserting the mounting screw 64 into the bolt hole 62 and the elongated holes 11, 11 through the bolt hole 3, and tightening the nut 65 at the desired adjustment length position. Next, the rim contacting position of the brake shoe 2 needs to be set so that the front brake is up in the front and the rear brake is in the front down, based on the position perpendicular to the brake arm. The holding part 5, which determines the posture of the brake arm, is integrally formed with the connecting piece part 6, so it is only necessary to set the position of the holding part 5 in advance at a predetermined angle to raise the front and lower the front at the time of molding. There is no need to go through the trouble of adjusting the front up or down each time. In addition, in the case of a rear brake, conventionally a brake shoe stopper (boat stopper) with an L-shaped cross section is attached to the brake shoe, but in this embodiment, a stopper that protrudes outward from the rear end of the holding part is attached to the brake shoe. If a piece (not shown) is provided, it can be easily manufactured by integral molding, and the trouble of installing a brake stem stopper can be saved. In the case of this embodiment, a protruding piece 66 extending upward is provided at the upper part of the rear side of the bracket piece of the connecting piece 6, and a hooking step 67 is formed on the front side of the protruding piece 66. The illustrated example has a configuration in which a spring latching portion is formed by the wall surface of each brake arm and the latching step portion 67 when each brake arm is fixed. Therefore, when the spring is installed, the center portion of the spring 68 is supported by a spring support portion provided on a center bolt (not shown), and the active ends on both sides are supported by the wall surface of each arm and the latching step portion of the brake shoe portion. The brake is latched onto a spring latching portion formed by the brake lever and transmits the brake return turning force. The joint surface of the leather is placed horizontally (orthogonal to the rim contact surface) in the concave portion 4 of the holding member 5 configured in this way.
Then, the brake shoe 2 is fitted. On the other hand, on the lower wall surface 41 of the holding member 5, which forms the wall surface on the outer periphery of the recessed recess 4, two screw grooves 7 communicating with the recessed recess 4 are arranged at two locations in the front and rear. The tightening screws 8, 8 are screwed into the threaded grooves 7, 7, and the tightening force presses the brake shoe 2 in the tightening direction within the concave portion 4 to securely hold the brake shoe 2. With this structure, even if the tip of the brake shoe 2 comes into contact with the rim during braking and a frictional force is generated, the stress is evenly distributed to the joint surfaces of the leathers 21, 21, 21, so that the leather 21 There is no risk of part of the material coming off. Further, since the tightening screw applies a pressing force in the so-called skewering direction to the leathers arranged in series, a reliable and strong tightening force can be obtained. It is sufficient that the tightening screws 8, 8 are provided at least on the lower wall surface 41 or the upper wall surface 42, and it goes without saying that they may be provided on both.

[Effect of the idea]

With the above configuration, the upper or lower wall surface of the holding part can be set to a longer depth than conventional ones, so it is possible to use as large a screw as possible for tightening the brake shoe. Moreover, since the screw can be tightened perpendicularly to the brake shoe, the fixing force can be increased. In addition, since the connecting piece is in parallel contact with the brake arm and tightened with bolts, the center of gravity of the pressure point and the braking force point during braking coincide, so that the braking efficiency can be improved. At the same time, the brake shoe is fitted without any gaps, thin leather is layered on top and bottom, and is fixed to the holding member with tightening screws, so it will not twist or peel off due to repeated braking. do not have. This laminated brake shoe is advantageous because it has a simple structure and can perform a braking action similar to that of thick (single) leather.

[Brief explanation of the drawing]

The drawings show a preferred embodiment of the bicycle brake shoe structure of this invention, in which Fig. 1 is a partial sectional view of the main parts seen from the front, Fig. 2 is a side view of the same, and Fig. 3
The figure is a perspective view of the same. 2 is a brake shoe, 3 is a holding member, 4 is a concave portion, 5 is a holding portion, 6 is a connecting piece, 7 is a screw hole, 8 is a tightening screw, 21 is leather, 41 is a lower wall surface, 42 is a Upper wall.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A connecting piece that connects the lower end of a substantially flat brake arm from both front and rear sides; A holding part with a substantially box-shaped cross section that continuously protrudes inward (on the rim abutting side during assembly) while extending parallel to the rim (when assembled); and a brake that is fitted into an opening formed inside the holding part almost without any gaps. The brake shoe is made of a laminate made of a plurality of leathers bonded vertically, and at least one of the opposing upper wall surface or lower wall surface of the holding portion is set long toward the rim side, and A bicycle brake shoe structure characterized in that a tightening screw is screwed into a surface in the vertical direction and the brake shoe is pressed and fixed at the tip of the tightening screw. (2) The bicycle brake shoe structure according to claim 1, wherein the tightening screws are provided at two locations spaced apart from each other on the front and rear of the lower wall surface of the holding portion.