EP0638040A1

EP0638040A1 - Rim brake for bicycles

Info

Publication number: EP0638040A1
Application number: EP92909341A
Authority: EP
Inventors: Jörgen ERICHSEN
Original assignee: Hans Helmig GmbH
Current assignee: Hans Helmig GmbH
Priority date: 1990-10-27
Filing date: 1992-04-30
Publication date: 1995-02-15
Also published as: WO1993022189A1; DE4034271C2; DE4034271A1

Abstract

A rim brake is disclosed, in particular a double jaw brake having one or several rubber spring elements (6) which restore the brake jaws (3) to their initial position or which prestress them in the initial position. These rubber spring elements allow a completely new braking performance, in comparison to the conventional, rigidly mounted brakes, such as the cantilever brakes, because the rubber yields to a certain extent, according to its Shore hardness, although it ensures the required stiffness. The design of a rim brake with a rubber spring element is substantially more simple and unproblematic, as no seals are required, and the user can mount such a rim brake without danger of mistakes.

Description

DESCRIPTION

Rim brake for a bike

The invention relates to a rim brake for a bicycle, in particular for a caliper brake, which is of the type of a cantilever or middle pull brake, in which one or more rubber spring elements bring about the return and prestressing of the brake arms in their starting position.

If in the following we speak of a rubber spring element, it means one that consists of both natural rubber and other elastomers.

Such an invention is of great practical and above all security interest and value. After all, the demands on a bicycle have become much greater, especially for the braking system.

For example, consumer associations are calling for the quality of bicycle brakes to be improved. In a press release dated September 22, 1990, Bonn (AP), the AgV demands compliance with certain guide values. According to the applicable standard, the route must not be longer than 5.5 meters in dry weather and at a speed of 25 km / h.

In all of the brakes for bicycles known to date, in particular for the types mentioned above, as are also known from file numbers DE-OS 31 41 004 A1, DE-OS 37 20 115 A1 and DE-OS 37 22 712 A1 have become known, the resetting of the brake arms is carried out by various forms of springs made of spring steel, such as coil springs and leg springs.

Bicycle brakes have also become known in which the resetting takes place by means of compression and tension springs as well as leaf springs and torsion bar springs.

With all bicycle brakes of the types listed above, the brake arms are mounted on plain or roller bearings. On the one hand, this type of storage must be manufactured precisely and therefore has little play in the bearing point, and a braking operation therefore has a hard and abrupt effect. On the other hand, if there is too much play between the bearing points, the brake arm will tilt and this can result in the driver becoming blocked and therefore falling.

It is also common to all bicycle brakes that the brake arms are reset by means of coiled torsion springs (helical torsion springs), it being known that it is difficult to design the spring force of each return spring uniformly, which leads to an additional spring adjustment direction, and that means a More functional parts.

In addition, the leg springs must be of different types, i.e. there are springs wound on the right and left, since both brake levers have to be preloaded outwards. So that these springs cannot be confused, they are color-coded.

Bearings, as are the case with the brakes known to date, must be serviced. If there is insufficient lubrication, and this is the rule, this leads to excessive wear. They can even get stuck after a long standstill. Additional cover caps must protect the springs and bearing points against dirt and moisture. The invention is therefore based on the object of improving and designing a rim brake of the type mentioned at the outset such that on the one hand the braking properties are improved and the brake is prevented from locking and on the other hand the brake arms are reset by means of a rubber spring element , which can take over the storage of the same at the same time, which manages with a smaller number of components, and the setting of the spring preload can be done in a simple manner by the user.

This object is achieved in a generic embodiment by the characterizing features of claim 1.

Appropriate equipment is the subject of the subclaims.

The advantages achieved by the invention are that the brake arms are reset by rubber spring elements which are known for their simple, low-maintenance and inexpensive construction.

Since rubber spring elements can be actuated independently of the direction, a mix-up is impossible.

A major advantage of the invention is that there is no need for a bearing (plain or roller bearing), since the rubber spring elements perform this task according to the invention.

This eliminates the need for expensive and maintenance-intensive bearings, as these elements are insensitive to dirt, moisture and impact.

The number of components is reduced and the adjustment or pretensioning of the brake arms is simplified so that it can also be carried out by the user.

These purely technical advantages are the prerequisite for the much more important functional advantages, such as more sensitive braking, because when the pull cable is pulled heavily, the brake arms around the The elastic modulus of elasticity of the rubber spring element easily yields, and so the brake cannot be blocked, since the brake arms can easily yield both in the axial and in the radial direction, depending on the Shore hardness of the rubber, and due to the structural design. Another advantage is the internal damping of the entire brake system, as is achieved, for example, by a hydraulic system.

Further details of the invention result from the following description of an exemplary embodiment illustrated in the drawing. Show it:

Fig. 1 is a front view of the rim brake according to the invention for a bicycle

Fig. 2 The view of a section A-A through the axis of the bearing of a brake arm

Fig. 3 is a view of a partial section B-B through the axis of the bearing of a brake arm

4 The view of a section A-A through the axis of the bearing of a brake arm

Fig. 5 is a view of a partial section C-C through the axis of the bearing of a brake arm

The rim brake illustrated in FIG. 1 contains, as essential parts, two brake arms 3 which are designed in the usual way and are each pivotably mounted on a bearing base 1, which are welded to the front or rear wheel fork G, and each with a rubber spring element 6 between them the brake arms 3 and the bearing pin 2 is arranged so that it biases the brake arms 3 and thereby enlarges the distance between the brake shoes 10. A pull cable A, which is connected at one end to a brake lever, is provided at the other end with a pull hook B, in which a connecting cable C is guided, on both ends of which the brake arms 3 are suspended. Rubber spring elements, which consist for example of natural rubber or other elastomers, can be of different constructions. For example, three exemplary embodiments are described here, two of which are explained in more detail in the drawing.

In example 1, according to FIGS. 2 and 3, the rubber spring learning 6 consists of an outer square tube or opening 4, in which a smaller square tube 5 is arranged offset by 45 ° in such a way that an elastic member is formed in each of the four triangles formed shear ring 8 is clamped.

In example 2, without drawing, the rubber spring element, of the type a torsion thrust sleeve spring, consists of an outer and an inner sleeve and which are firmly bonded by vulcanization to an elastomeric material.

In example 3, the rubber spring element 6, of the type of a rotary thrust disk spring, consists of a front and a rear bearing disk 13 and 14, which are firmly bonded by vulcanization to an elastomeric material.

The principle of operation of all three elastic spring elements is the same. A spring effect as a torsion thrust spring is achieved when one of the two non-elastic parts, such as a sleeve, washer or square tube, is rotated against the other.

The embodiment shown in FIG. 2 shows a rim brake with the spring element 6 according to Example 1. Here, a square opening 4, in the center of gravity S of the brake arm 3, is worked out so that an inner, square bearing bush 5 is offset by 45 °, and an elastic round ring 8 is clamped into the resulting four triangles. Via a front and rear support disk 11 and 12, the inner bearing bush 5 is non-positively connected to the bearing base 1 by the fastening screw 7 on the bearing journal 2 and the brake arm 3 is guided when pivoting.

The rubber spring element 6 listed in Example 2 can be compared in principle with Example 1 and is therefore not described further.

Another embodiment is shown in FIG. 4, in which the rubber spring element 6 is designed according to Example 3 described above, a receiving bore 20 being present in the pivot point S of the brake arm 3, into which, for example, the front bearing disk 13 of the rubber spring element 6 is positively connected via a toothing 21 to the brake arm 3, and the rear bearing plate 14 is positively connected to the bearing pin 2 via a toothing 22. The front bearing disc 13 is rotatably supported on the journal 2, and the rear bearing disc 14 is rotatably supported in the brake arm. The fastening screw 7 holds the brake arm 3 in position.

Since the rubber spring elements 6 and the brake arms 3 can be combined to form a unit, the user can easily assemble and adjust the pretensioning or restoring force F1 of the two brake arms 3.

In example 1, the pretensioning force is set by loosening the fastening screws 7 and rotating the brake arms 3 with the elastic spring elements on the bearing journal 2 by a certain amount in the R and L direction. By subsequently tightening the fastening screws 7, the brake arms 3 are pretensioned and now, when the pull cable A is actuated, exert a restoring force Fl which becomes greater the greater the angle of rotation is selected. In example 2, the prestressing of the rubber spring element 6 takes place by turning the rear bearing disc 14 relative to the front bearing disc 13 by loosening the fastening screw 7 so that the rear bearing disc 14 is released from the toothing 22 of the bearing journal 2. By turning the brake arm 3 by a certain amount outwards in the direction R and L, the rear bearing disk 14 is pushed back onto the toothing 22 and then held with the fastening screw 7.

Although several exemplary embodiments have been described, they are only examples of the invention and do not constitute a restriction.

REPLACEMENT LEAF

Claims

PATENT REQUEST E rim brake for a bicycle

1. Rim brake for a bicycle, in particular for a Zangen¬ brake, which is of the type of a cantilever or middle pull brake, characterized by one or more rubber spring elements which are made, for example, of natural rubber or other elastomers, which on the one hand take over the bearing of the brake arms and on the other hand cause the return and bias of the brake arms to their initial position.

2. Rim brake for a bicycle according to claim 1, characterized in that the rubber spring elements are preferably arranged in the pivot point of the brake arms or on the swivel base.

3. Rim brake for a bicycle according to claim 1 to 2, characterized. In that the rubber spring elements simultaneously take over the storage of the brake arms.

4. rim brake for a bicycle according to claim 1 to 3, characterized in that the rubber spring elements act both as a torsion spring or as a compression spring or as a combination of both types.

5. rim brake for a bicycle according to claim 1 to 4, characterized in that the rubber spring elements are positively and / or non-positively arranged in the brake arms and on the Schwenk¬ base.

6. rim brake for a bicycle according to claim 1 to 5, characterized in that the rubber spring element is preferably vulcanized into the brake arm.

ERS