JPS59144828A - Brake for bicycle - Google Patents

Abstract

PURPOSE:To prevent partial abrasion of a braking surface by supporting the forward side of a leading shoe on a support member, the movement of which is regulated along the turning direction of a drum through an anchor to obtain the braking force more than a leading effect. CONSTITUTION:A shoe 2 is brought into pressure contact with a drum 1 to apply braking force to the drum 1, and the turning torque of the drum 1 works upon the leading shoe 2, so that self-braking force works upon the leading shoe 2. The leading shoe 2 is moved in the same direction as the turning direction of the drum 1 by the self-braking force, and the movement causes an anchor to operate counterclockwise on a supporting position for supporting the anchor on a support member 10, so that the shoe 2 is forcibly brought into pressure contact with the inner peripheral surface of the drum 1 strongly. Thus, a very great braking force can be obtained by large contact pressure of the anchor 5 and self-braking force, though an input is small.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bicycle brake, and more particularly, to a bicycle brake which is braked by pressing a shoe having an arcuate braking surface facing the peripheral surface of a drum that rotates together with the hub into pressure contact with the peripheral surface of a drum that rotates together with the hub. Regarding brakes.

Conventionally, this type of brake mainly includes a leading shoe with an arc-shaped braking surface and a cam body with one end of the trading shoe pivotally connected to a fixed member and a pair of cam surfaces between the other end. An inwardly expanding type drum brake is known in which the shoes are rotatably interposed and connected to the cam body, and the shoes are brought into contact with the inner circumferential surface of the drum by operating an operating body connected to the cam body.

However, in the case of this conventional brake, the cam body must be disposed within the drum, and the length between the cam surfaces of the cam body is specified to be relatively short. ,
The operating body has one end attached to a central position of the cam body provided in the drum, and the other end is pulled out radially outward from the outer peripheral surface of the drum, and an operating wire is fixed to the pulled-out end. As necessary, the length from the rotation center position of the cam body to the cam surface '+), and the length l,) from the attachment position of the operating body to the cam body to the fixed position of the wire. If the ratio (A < 1m) becomes too large, the operation stroke of the wire required for braking becomes larger than the appropriate stroke, and the grip dimension on the brake lever side becomes a dog, making it difficult to perform the braking operation. There was a problem.

In addition, in the case of conventional internally expanding drum brakes, a self-braking force acts on the leading shoe of the leading shoe and the trading shoe, and the braking force can be increased by the effect of this self-braking force, that is, the leading effect. On the other hand, the trading shoe has no self-braking force and only a small braking force can be obtained.However, since the leading shoe and trading shoe are used, the structure is complex, there are many parts, and the cost is 1-
There is a problem. Moreover, since the structure is such that one end of the pair of shoes is pivotally connected to the fixing member and the cam body is provided between the other end edges, the part of the braking surface of the arcuate shoe that is pivoted to the fixing member is The braking surface on the cam body side is more likely to wear than the braking surface on the landing side, and there is a problem that the braking effect deteriorates due to uneven wear, and it is not possible to obtain a braking force greater than the above-mentioned leading effect. The braking force was limited.The present invention was invented in view of the above-mentioned conventional problems.
The purpose is to simplify the structure by using only the IJ-ding shoe on which self-braking force acts, and to have a structure in which an operating body is attached to one end of the connolly leading shoe so that the operating body can be placed outside the drum. The front side of the leading shoe is supported via an anchor on a support member whose movement in at least the rotational direction of the drum is regulated, so that a braking force greater than the leading effect can be obtained and uneven wear of the braking surface can be prevented. The point is to make it possible.

Therefore, the configuration of the present invention includes a drum that rotates together with the hub and a leading shoe having an arcuate braking surface facing the circumferential surface of the drum, and the leading shoe is provided on the rear side of the drum in the direction of rotation of the drum. an operating body for moving the shoe in the direction of the surface of the drum, and a support member that restricts movement at least in the rotational direction of the drum, and the front side of the shoe is pivoted to an anchor supported by the support member. As a result, the operating body can be formed freely without being restricted by the drum, etc., and has a simple structure.Moreover, when braking, the anchor is actuated and the shoe is attached to the circumferential surface of the drum. It is possible to make a strong pressure contact with the material.

An embodiment of the brake of the present invention will be described below based on the drawings.

The brake shown in the figure is the hub collar (
A drive base (1) is fixed by screwing to the hub body (hook) on the outside of the drum (Hl), and the drum (
A leading shoe (2) having an arcuate braking surface (21) facing the inner circumferential surface of the drum (1) is installed inside, and the leading shoe (2) is located on the rear side (2a) of the two shoes in the forward rotational direction of the drum (1).
An operating body (6) for moving the shoe (2) in the circumferential direction of the drum (1) is attached to the operating body (6)'.
A fixing member (4) that fixes the middle part of the
), and the front side (2b) of the shoe (2) in the forward rotation direction of the drum (1) is rotated to a support member (10) whose one end is formed integrally with the fixing member (4). The operating body (6) is actuated by pulling the operating wire (W'5) which is pivotally connected to a freely movably supported rod-shaped anchor (5) and fixed to the operating body (3). be.

In the above configuration, the drum (1) has a cylindrical portion (1
1), a disk-shaped support part (12) extending radially inward from one end of the cylindrical part, and a cylindrical boss part (16) provided at the center of this support part.

Further, the leading shoe (2) is formed to have a U-shaped cross section, and the outer surface of the bottom surface thereof serves as the braking surface (21), and the rear side (2a) of this shoe (2)
) End-side, the cylindrical part (11) of said drum ('1)
An extension part (22) protruding further radially outward is provided, and the operating body (6) is attached to the tip of the extension part (22) via the mounting shaft (6). 2)
The tip of the anchor (5) is pivotally attached to both sides of the front side (2b) via a pin (7).

Further, a spring receiving piece (2 ro) is provided on the rear side (2a) of the shoe (2), and this spring receiving piece (2 ro) and a spring receiving piece (2 ro) provided on the fixing member (4) 41), a return spring (8) is interposed to bias the shoe (2) in a direction away from the inner peripheral surface of the drum (1). Although it is preferable to provide the braking surface (21) of the shoe (2) with a lining layer (24) as shown, this lining layer (24) is not absolutely necessary.

The operating body (6) is composed of a bell crank, and its middle bent portion is pivoted to the fixing member (4) via a pivot shaft (9), and one end is connected to the shoe (2). Extension part (22
), and the aforementioned operating wire (W) is attached to the other end, so that the shoe (2) is directly actuated by the swinging of the operating body (6) caused by the pulling operation of the wire (W). . Further, the mounting position of the operating body (3) to the extension portion (22) is the mounting position of the operating body (lo) to the fixing member (4) and the mounting position of the anchor (5) to the supporting member (10). The operating body (
3) on the rear side in the forward movement direction (clockwise in FIG. 1), so that when the operating body (6) swings in the forward movement direction by the pulling operation of the operating wire (W), the shoe (2) Drum (1
) can be moved by a slight stroke in the forward rotation direction. The operation body (6) is attached to the extension part (22) using the attachment shaft (6) as shown in the figure, but other than that, one of the operation body (6) and the extension part (22) is used. A concave holding portion is provided on the other side, and a fitting portion that fits into the holding portion is provided on the other side, and the operating body (6) is attached to the extension portion (22) by fitting the fitting portion into the holding portion. May be installed. Further, as a means for moving the shoe (2) in the same direction as the rotational direction of the drum (1), as described above (specifying the attachment position of the operating body (6) to the extension part (22)) In addition, a gap may be provided at the attachment position of the operation body (6) to the extension part (22) to allow movement of the shoe (2), and as described later, a gap may be provided to allow the movement of the shoe (2). It may be formed from a flexible material, and its structure is not particularly limited.

Further, the anchor (5) is configured such that the shoe (2) contacts the inner circumferential surface of the drum (1), and the rotational torque of the drum (1) acts on the shoe (2). ) When a self-braking force acts on the shoe (2) due to the torque received from the shoe (2), the front side (tTJ) of the shoe (2)
b) is forcibly brought into contact with the inner circumferential surface of the drum (1), and has an attachment part (5m) to the support member (4) at one end, and the pin (7) at the other end. When a self-braking force operates on the shoe (2), the mounting portion (5b) is
The shoe (2) is rotatably supported via a support shaft (20) at a position where it can be moved radially outward of the drum (1).

Further, the fixing member (4) is disposed axially outward of the drum (1), and is a disc-shaped plate body having a through hole in the center for receiving the hub shaft (H,). An arm (41) protruding radially outward is provided on the outer periphery and side surface thereof, and the operating body (6) is pivotally attached to the arm (41).

Further, the supporting member (10) uses a part of the fixing member (4) as a supporting member, but other parts formed separately from the fixing member (4) may be used by fixing means such as welding or It may be fixed using a fixture such as a set screw, or it may be supported by a member supported by the fixing member (4) or a stationary member such as a bicycle frame that supports the fixing member (4). You can also use it as

In the figure, (0) is an outer tube for guiding the operating wire (w), and (30) is a spring for returning the operating body (6).

However, in the above configuration, when braking is performed while the bicycle is traveling in the forward direction, that is, when the drum (1) rotates in the forward direction (clockwise rotation in Figure 1), the operation lever (not shown) is used to This is done by pulling the operating wire (W), and by pulling the wire (W), the operating body (6) swings clockwise in FIG. 1 about the pivot shaft (9), and The leading shoe (2) moves in the needle direction, and the braking surface (21) of this shoe (2) comes into pressure contact with the inner peripheral surface of the drum (1).

By pressing the shoe (2) against the drum (1), a braking force is applied to the drum (1). At this time, the rotational torque of the drum (1) acts on the leading shoe (2), and the torque received from the drum (1) causes a self-braking force to act on the leading shoe (2). The leading shoe (2) moves in the same direction as the rotation direction of the n1J drum (1), and due to this movement, the anchor (5)
The shoe (2) operates counterclockwise in FIG.
1) is forcibly and strongly pressed against the inner peripheral surface. Therefore, even if the input is small, a very large braking force can be obtained due to the large pressing force by the anchor (5) and the self-braking force.

Also, when the bicycle is moving backwards or when braking is performed to prevent backward movement on a slope, the wire (W) is pulled in the same way as braking when moving forward.

In the embodiment described above, the anchor (5) is rotatably supported on the support member (10), but it may be fixed.

In this case 1. The anchor (5) is, for example, flexible;
When the leading shoe (2) moves in the same direction as the rotation direction of the drum (1) due to self-braking force, the anchor (
5) may be slightly bent.

Furthermore, in the above explanation, the supporting member (10) is replaced by the fixing member (4).
) to make it inoperable; however, the supporting member (10) may be formed separately from the fixing member (4), for example, to attach the drum (1) to the fixing member (4). The drum (1) is supported so that its movement in the rotational direction is regulated and the movement of the drum (1) in the radial direction is allowed within a certain range.
When the leading shoe (2) moves in the same direction as the rotational direction of the drum (1) due to the braking force, the support member (1-0) moves in the radius of the drum (1) via the anchor (5). Acting inward in the direction, the drum (1
) may be brought into contact with the outer circumferential surface of the boss portion (16), and a braking force may be applied to the drum (1) through contact with the outer circumferential surface of the boss portion (13). In this case, it is preferable to provide a lining layer on the contact surface of the support member (10) with the outer peripheral surface of the boss portion (13).

As described above, the present invention uses only a leading shoe as a shoe having an arcuate braking surface facing the circumferential surface of a drum that rotates together with a hub, and the shoe is placed on the rear side of the shoe in the direction of rotation of the drum. An operating body for moving the drum in the horizontal direction is attached, and a support member is provided that restricts movement of the drum at least in the rotational direction, and the front side of the shoe is pivoted by 6° to an anchor supported by the support member. The operating body can be arranged outside the drum so that the shoe can be operated from outside the drum. Therefore, the first operating body can be operated without being restricted by the drum or the like. The operation stroke required for the operation operation, for example, braking the operation wire, can be formed to be shorter than the appropriate stroke. As a result, the grip dimension on the brake lever side can be reduced, making it easier to perform braking operations.

Moreover, since a leading shoe is used, braking can be achieved by the leading effect, and when a self-braking force is applied to the shoe using an anchor, the shoe is forcibly and strongly pressed against the surface of the drum to achieve braking. Because of this, even if the input is small, a very large braking force can be obtained by the braking force due to the above-mentioned leading effect and the large pressure contact force by the above-mentioned anchor, and the stopping distance of the bicycle when running at high speed can be reduced to a predetermined distance. This can be further shortened.

Furthermore, by using the anchor to press the shoe against the surface of the drum, uneven wear of the braking surface of the shoe can be prevented, and a reduction in braking force due to this uneven wear can be prevented. Since only the leading shoe is used, a large braking force can be obtained, and the structure is simple and the number of parts can be reduced, resulting in cost reduction.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view showing an embodiment of the brake of the present invention, Fig. 2 is a sectional view taken along the line If-II in Fig. 1, and Fig. 6 is a cross-sectional view of the
It is a sectional view taken along line III-M in FIG. (1)...Drum (2)...Leading shoe (6)...Operating body (5)...Anchor (21)...Braking surface (10)...Support member - Attorney Attorney Shizu 1) Hisashi Nao Figure 2 Figure 3 Procedural amendment 1 Indication of the case 1981 Patent License No. 17704 2 Name of the invention Bicycle brake 3 Person making the amendment Relationship to the case Applicant address Osaka 3Y77 Yachi (24-ro) Oimatsu-cho, Sakai-shi, Osaka Prefecture Kenno Kogyo 4-bed Shikikaiso L Name Director and President Shozo Shimano 4 Agent Address 5-5 Yonezawa Hill, 1-9-9 Sumiyoshibashi-cho, Sakai-shi, Osaka 590 Date of amendment order Initial issue 6 Subject of amendment (1) The following explanation is added to the last line of page 11 and the first line of page 12 of the specification. As for the anchor (5), as shown in Fig. 1, a long mounting space is formed above the mounting position to the leading shoe (2), so this mounting space (
At this point, the anchor (5) can be installed with a longer swinging stroke, so that the self-braking force acts and forces the anchor (5) against the leading shoe (2) by 1 m on the inner circumference of the drum (1). Pressure braking stabilizes the direction of the feeding operation, and even if the leading shoe (2) is worn out, the leading shoe (2) can always be accurately fed regardless of the degree of persimmon.

Claims (1)

[Claims] A drum that rotates together with a hub and a leading shoe having an arcuate braking surface facing the curved surface of the drum, the shoe being moved toward the rear in the direction of rotation of the drum in the circumferential direction of the drum. In addition to attaching a 5-operating body, a support member is provided that restricts movement of the drum at least in the rotational direction, and the front side of the shoe is pivotally connected to an anchor supported by the support member. Bicycle brake.