DE29924519U1 - Hydraulic rim brake for bicycle ha brake cylinder actuating pad and mounted on pivoting frame bracket - Google Patents

Abstract

The hydraulic rim brake for a pedal cycle has a brake cylinder (100) actuating a brake pad (103). The brake cylinder has a connecting bracket (302) for mounting it on the bicycle frame (2'') so that it can pivot around an axis orthogonal to the brake pad mounting. The bracket has a bore to receive the pivot pin (303).

Description

Dipl.-Chem. Dr. Steffen ANDRAE

Dipl.-Phys. Dieter FLACH

Dipl.-Ing. Dietmar HAUG

Dipl.-Chem. Dr. Richard KNEISSL

Dipl.-Ing., Dipl.-Wirtsch.-Ing. Friedrich BAUER

Dipl.-Phys. Dr. Martin FRIESE

Balanstrasse 55

81541 Munich Our reference number:

2 984 A GMDE

Applicant:

Gustav Magenwirth GmbH & Co D-72574 Bad Urach

Brake cylinder for a rim brake

The invention relates to a brake cylinder for a rim brake according to the preamble of claim 1 or a rim brake with such brake cylinders. In particular, the invention relates to a brake cylinder for a hydraulic rim brake for bicycles and a hydraulic rim brake.

A brake cylinder according to the preamble of claim 1 is known from DE 42 32 598 C2.

In the case of the rim brake shown in DE 42 32 598 C2 with the brake cylinders disclosed therein, it is difficult to dismantle the wheel if the tire mounted on the wheel rim is significantly wider than the wheel rim, because the tire has to be moved through the gap between the two brake pads arranged on the brake cylinders. Dismantling the wheel is particularly difficult when using the thick tires used on mountain bikes, for example.

It is therefore the object of the invention to provide a brake cylinder for a rim brake or a rim brake which allows easy disassembly of the wheel with a simple construction of the rim brake.

The object is achieved with a brake cylinder according to the features of claim 1 or a rim brake with the features of one of claims 11 to 14. Advantageous embodiments of the invention are specified in the dependent claims.

In the context of this invention, the direction of the receiving device for a brake pad means a direction tangential to the rim in relation to an area of the rim where the brake pad engages the rim. This direction is equivalent to the running direction of the rim at the point where the brake pad engages the rim.

In the context of this invention, the direction of the main axis of the brake cylinder means a direction in which the brake pad is moved towards or away from the rim. As a rule, a piston in the brake cylinder is moved along the main axis of the brake cylinder to actuate the brake.

The inventive design of the brake cylinder according to claim 1 or of the rim brake according to one of claims 11 to 14 has the advantage that, due to the pivotable arrangement of the brake cylinder(s), the wheel can be removed and reinstalled easily and quickly.

In addition, the inventive design of the brake cylinder according to claim 1 or of the rim brake according to one of claims 11 to 14 has the advantage that a complex readjustment of the brake cylinders with respect to the rim is not necessary, because the pivoting of the brake cylinders returns the brake cylinders to the old setting after the wheel has been reinstalled.

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This is particularly the case because the brake cylinders do not have to be removed from the frame to dismantle the wheel and a defined guide of the brake cylinders is guaranteed during the swivel movement. In this respect, the brake cylinders can always be returned to exactly the same starting position after each swivel movement.

A well-known solution for attaching a brake cylinder of a hydraulic rim brake to the frame parts of a bicycle is a two-part adapter with a clamp-like mount for the brake cylinder. The adapter is attached to a cantilever brake base. Degrees of freedom for aligning the brake cylinder in all directions for adjusting the rim brake are provided by a spherical mount.

The known solution has the disadvantage that complex, expensive parts are used. The parts are also heavy and large. The number of parts is large. The installation of the rim brake requires complex adjustment work. The complex adjustment work is also required when reinstalling the wheel.

According to the invention, a brake cylinder or a rim brake is provided which has at least one feature or any combination of the following features:

1) The brake cylinder is pivotably mounted on the bicycle front fork or the bicycle rear frame.

2) The pivot axis is largely parallel to the fork tube or seat stay.

3) The pivoting takes place around the longitudinal axis of the fork tube or the seat stay.

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4) The pivot axis is essentially perpendicular to the brake pad.

5) The swivel axis is located inside the brake cylinder. This has the advantage that a very compact design of the brake cylinder can be realized.

6) The pivot axis is located outside the brake cylinder. This has the advantage that the design of a specific version is simpler because collisions between components during the pivoting movement of the brake cylinder can be more easily avoided.

7) The brake cylinder is mounted in front of the supporting part when viewed in the direction of travel.

8) The brake cylinder supports the contact forces and main braking forces in the force flow in a form-fitting manner.

9) Swinging out one or both brake cylinders ensures quick wheel removal.

10) The braking forces in the reverse direction are supported by a releasable locking device.

11) The swivel device is designed in such a way that a defined guidance of the brake cylinders is guaranteed during the swivel movement. In this respect, the brake cylinders can always be returned to exactly the same starting position after each swivel movement.

12) The degrees of freedom in cultivation are limited to a reasonable range.

The invention has the following particular advantages:

Both the brake cylinder and the rim brake

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Overall it is simple in construction and has few parts.

Furthermore, production is cost-effective and requires little installation space.

The inventive design results in a low weight.

The brake cylinder and its mounting can be easily integrated visually.

Wheel assembly and disassembly is quick and easy.

The brake pad adjustment does not have to be carried out again when the wheel is reinstalled, but remains the same.

The rim brake or brake cylinder is installed easily, quickly and clearly. There is no need for complex adjustment.

In order to adjust the position of the free end of the piston within the cylinder relative to the brake cylinder and thus relative to the rim, it is known in rim brakes to introduce hydraulic fluid into the pressure chamber of the brake cylinder using a screw on the master cylinder. The piston moves in the direction of the rim against the effect of a spring arrangement. By loosening the screw on the master cylinder, hydraulic fluid is drawn from the pressure chamber. As a result, the piston moves back away from the rim due to the force of the spring device.

The free end of the piston is the end of the piston that, in the case of a brake system mounted on a bicycle,

cylinder is located opposite the rim of the bicycle and, when the brake cylinder is actuated, causes a brake pad to be moved towards the rim.

In a hydraulic rim brake, two brake cylinders are usually connected to one another with a hydraulic line in such a way that when the brake lever is operated, both brake cylinders are actuated equally and the respective pistons are disengaged from the cylinders equally. Accordingly, adjusting the adjusting screw on the master cylinder simultaneously adjusts the rest position of the pistons of both brake cylinders. However, there is a need to adjust the rest position individually for each brake cylinder to ensure optimal adaptation of the brake to the rim.

For example, it is known for disc brakes to use an open system instead of a closed system. An open system means a system with an expansion tank that is connected to the pressure chamber of the brake calliper when the brake lever is in the resting position. If the volume of the pressure chamber is changed by adjusting the piston in the brake calliper, the corresponding compensation can be carried out with hydraulic fluid through the expansion tank. When the brake is applied, the connection between the pressure chamber and the expansion tank is blocked. However, an open system has the disadvantage that it is relatively complex due to the need for an expansion tank and is therefore expensive to manufacture. For this reason, closed systems without an expansion tank are usually used for hydraulic rim brakes.

In order to be able to adjust the relative position of the free end of the piston with respect to the cylinder independently of the other brake cylinder, the brake cylinder according to the invention preferably has an adjusting device with which the relative position of the free end of the piston in the axial direction

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in the cylinder is adjustable in such a way that the volume of the pressure chamber remains essentially unchanged. This has the advantage that when the free end of the piston is adjusted in the axial direction with respect to the cylinder, there is no exchange of hydraulic fluid with the system. Therefore, the free end of the piston in a single brake cylinder can be adjusted independently of an expansion tank.

For example, the relative position of the free end of the piston with respect to the cylinder can be adjusted using an adjusting piston that moves the piston (and thus also the free end of the piston) together with the pressure chamber in the cylinder in an axial direction. This changes the relative position of the free end of the piston with respect to the cylinder, while at the same time the volume of the pressure chamber remains unchanged.

Advantageously, the adjusting piston is screwed into an area of the cylinder. This has the advantage that the free end of the piston can be adjusted precisely and reliably.

Advantageously, the distance between the inflow into the pressure chamber and the adjusting piston in a position furthest away from the inflow is greater than the maximum possible adjustment path of the adjusting piston. This ensures the possible exchange of hydraulic fluid between the inflow and the pressure chamber at all times.

Advantageously, the adjusting piston has a locking ring which limits the maximum possible adjustment travel of the adjusting piston.

For example, the adjustment of the relative position of the free end of the piston with respect to the cylinder can be carried out by, according to a further embodiment, the

Invention the piston is designed to be adjustable in length. This has the advantage that the position and size of the pressure chamber do not have to be changed when adjusting the distance between the free end of the piston and the rim, because the relative distance between the free end of the piston and the rim or between the brake pad and the rim can be adjusted simply by adjusting the length of the piston.

The further development of the present invention with one of the described adjustment devices for the relative position of the free end of the piston with respect to the cylinder results in the further advantage that the brake pad adjustment can be carried out particularly easily and independently of the adjustment of the brake cylinder. In particular, the distance of the free end of the piston or the brake pad from the rim of the bicycle can be roughly specified by the inventive design of the pivoting attachment and finely adjusted by individually adjusting the relative position of the free end of the piston with respect to the cylinder of the brake cylinder. This further development results in an overall simple construction of the brake cylinder with few parts. In particular, the brake cylinder can be mounted on the bicycle precisely, easily and quickly.

The further development of the present invention with one of the described adjustment devices of the relative position of the free end of the piston with respect to the cylinder also results in the advantage that the position of the brake pad can be adjusted separately axially and readjusted as the pad wears.

According to one embodiment of the present invention, the locating member on the rear of the frame or fork is arranged in relation to the rim in such a way that when the brake cylinder is installed on the locating member and when the brake cylinder is pivoted into the braking point, the correct position between the brake pad and the rim is automatically established.

In the following, the invention is described by way of example with reference to the embodiments shown in the figures:

Fig. 1 shows a first embodiment of a rim brake according to the present invention with brake cylinders according to the invention in a braking position.

Fig. 2 shows a second embodiment of a rim brake according to the present invention with brake cylinders according to the invention in an assembly position.

Fig. 3 shows the preferred embodiment of a rim brake according to the present invention with brake cylinders according to the invention, which are shown partially in cross section.

Fig. 4 shows a brake cylinder from Fig. 3
larger scale.

in a

Fig. 5 shows a perspective view of the brake cylinder of Fig. 3.

Fig. 6 shows a top view of the brake cylinder of Fig. 3, cut away in the area of the fastening device.

Fig. 7 shows a cross section of a brake cylinder according to another embodiment of the present invention.

Fig. 1 shows a first embodiment of a rim brake according to the present invention with brake cylinders according to the invention in a braking position. Braking position means a position in which the brakes can be operated. The embodiment shown in Fig. 1 is for the assembly of the

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Rim brake suitable for both the front fork and the rear of the frame.

Two brake cylinders 4 are arranged on two frame parts 1 of a bicycle (not shown). The frame parts are either the fork legs of the front fork or the struts of the rear frame. A wheel, i.e. the front wheel or rear wheel, is arranged between the frame parts 1. For the sake of clarity, only part of the wheel rim 6 is shown schematically, on which a tire (not shown) is usually mounted.

A master cylinder (not shown) is attached to a handlebar (not shown) and is connected to the brake cylinders 4 in a known manner via hydraulic lines 9. When the hand lever of the master cylinder is operated, hydraulic pressure is built up in the hydraulic lines, which actuates the brake cylinders, which in turn press the brake pads 5 arranged thereon in a receiving device 10 against the rim 6.

An arrangement member 2 is attached to each of the frame parts 1. In the embodiment shown, the arrangement member 2 is designed as a tab. The arrangement members 2 are preferably each formed in one piece with the associated frame part 1. The arrangement members are preferably designed in such a way that the brake cylinder is set sufficiently precisely for braking operation by its fastening or arrangement on the arrangement member.

A brake cylinder 4 is pivotably mounted on each of the arrangement members. The brake cylinders 4 have a connecting member 41 at their ends facing away from the rim. In the embodiment shown, the connecting members 41 are projections with openings in which bolts 3 are received, each of which engages an arrangement member 2. The projections of the

Brake cylinders 4 are preferably each formed integrally with the associated brake cylinder 4.

The brake cylinders 4 are articulated via the bolts 3 to the frame parts 1 in such a way that the brake cylinders 4 can each pivot about the axis of the bolts 3. This pivot axis is essentially perpendicular to the direction of travel of the rim at the point where the brake pads engage the rim during braking. In other words, the pivot axis is essentially perpendicular to the brake pads or the mounting device. The defined guidance of the pivot device enables the brake cylinders to be positioned reproducibly even with repeated pivoting movements, which may occur, for example, when the wheel is being turned in or out.
expansion is required.

The possible swivel range of the brake cylinder 4 is limited by the arrangement member 2. When the brake is actuated, forces are transferred from the rim 6 to the brake pads 5 and from the brake pads 5 to the brake cylinder 4, the direction of which corresponds to the running direction 8 of the wheel at the point where the brake pads 5 act on the rim 6. These forces exert a torque on the brake cylinder 4 in relation to the swivel axes defined by the bolt 3, which turns the respective brake cylinder 4 in the direction of the associated arrangement member 2, i.e. the brake cylinder shown on the left in Fig. 1 anti-clockwise and the brake cylinder shown on the right in Fig. 1 clockwise. The brake cylinders 4 are positively received by the arrangement members 2. The force is therefore transferred from the brake cylinders 4 to the arrangement members and from the arrangement members to the frame parts.

According to an embodiment of the invention, the brake cylinders are arranged on the arrangement members so as to be pivotable about a pivot axis, that the force acting from the brake pad on the brake cylinder during braking is transmitted from the

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The centre of the contact area between the brake pad and the rim points approximately and preferably exactly to the tube centre of the frame part on which the brake cylinder is arranged. This has the advantage that only a small amount of torque, or no torque, is exerted on the frame part, which would cause the frame part to twist. The force acting on the brake cylinder from the brake pad during braking is the sum of the force exerted on the brake cylinder by the rim via the brake pad, which is directed parallel to the direction of movement 8 of the rim, plus the counterforce acting on the brake pad during braking, which is directed away from the rim perpendicular to the direction of movement 8 of the rim. The pivot axis is arranged in such a way that the force acting on the brake cylinder from the brake pad during braking exerts a torque on the brake cylinder in such a way that the brake cylinder is rotated into the braking position, in which it rests positively on the arrangement member.

The arrangement member 2, designed as a tab, forms a pivot point. The pivot point can be provided as a pin formed in one piece with the arrangement member or can be designed as a bolt 3. The pivot point serves as a mount for the brake cylinder 4. The reaction force is absorbed in a form-fitting manner by the arrangement member in the axial and tangential directions.

The brake cylinder 4 shown on the right in Fig. 1 is also provided with a locking member 42. The locking member is preferably formed in one piece with the brake cylinder 4. A bolt 7 is accommodated in an opening of the locking member 42 as a detachable securing element. The bolt can be pre-tensioned into a closed position by a spring, for example. In the closed position, the bolt 7 forms a positive connection between the brake cylinder 4 and the arrangement member 2. This fixes the brake cylinder with two axes relative to the arrangement member and enables rotation about the axis defined by the

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The pivot axis defined by bolt 3 is prevented. Particularly when reversing, the removable locking element prevents the brake cylinder from rotating about the pivot axis defined by bolt 3.

For dismantling the wheel, the bolt 7 is arranged detachably so that the brake cylinder 4 can be pivoted into the embodiment shown in Fig. 2 in the other embodiment of the invention.

In an embodiment of the invention (not shown), a pre-tensioning member causes the brake cylinder 4 to be pre-tensioned against the arrangement member 2 in the braking position. This ensures that the brake cylinder automatically rotates back into the braking position, for example from the assembly position. In addition, when driving forward, it is ensured that the brake cylinders are always arranged in the braking position.

Fig. 2 shows a second embodiment of a rim brake according to the present invention with brake cylinders according to the invention in an assembly position. Assembly position means a position in which the wheel can be assembled and disassembled.

The embodiment shown in Fig. 2 is suitable for mounting the rim brake both on the rear of the frame and on the fork that holds the front wheel.

The embodiment of Fig. 2 differs from the embodiment of Fig. 1 essentially in the design of the arrangement member 2 or 2'. The remaining identical parts have the same reference numerals as the embodiment of Fig. 1.

In the assembly position, the two brake cylinders 4 are shown pivoted by 90° from the braking position. As a result,

the brake pads 5 do not hinder the assembly and disassembly of the wheel.

To attach a brake cylinder 4 to a frame part 1, the brake cylinder 4 is simply pivotally connected at its connecting part 41 via the bolt 3 to the arrangement member 2 of the frame part 1. In the version with the detachable securing element, the bolt 7 is then inserted into the locking member 42 and connected to the arrangement member.

Figures 3 to 6 show the preferred embodiment of the invention.

Fig. 3 shows a rim brake according to the present invention with brake cylinders 100, 100' according to the invention, which are arranged on both sides of a rim 6. The mutually symmetrical brake cylinders 100, 100' are described in more detail using the brake cylinder 100 shown on the left in connection with Fig. 4. To actuate the brake, hydraulic fluid is fed into the left brake cylinder via a hose 20.

100. At the same time, hydraulic fluid is supplied to the right brake cylinder 100' via a second connection (not shown) to the pressure chamber 106 and a connecting hose 21. The hydraulic fluid is supplied in a known manner via a brake lever which actuates a master cylinder which presses hydraulic fluid into the hose 20.

Fig. 4 shows the left brake cylinder 100 of Fig. 3 on a larger scale. The brake cylinder 100 has a cylinder

101 with a through hole, the diameter of which is smaller in a first section 1011 than in a second section 1012. The first section 1011 has an internal thread. In the inner bore of the cylinder 101 are

From left to right, an adjusting piston 109, a pressure chamber 106 and a piston 108 are arranged.

The adjusting piston 109 has a section of smaller diameter on the left-hand side, which is provided with an external thread 111, and a second section of larger diameter, arranged to the right of the first section in Fig. 4, in which a groove is provided for a seal 105 which seals the pressure chamber 106. The adjusting piston 109 is screwed into the internal thread of the cylinder 101 with the external thread 111. A hexagon socket 110 is provided in the front face of the adjusting piston 109 for rotating the adjusting piston 109. The locking ring 112 limits the possible adjustment path of the adjusting piston 109 in the inner bore by abutting the internal thread in section 1011 of the cylinder 101 at the maximum possible adjustment. To the right of the adjusting piston is the pressure chamber 106, which is filled with hydraulic fluid during operation. The pressure chamber 106 is connected to the hose 20 via an inlet 107. The piston 108 is arranged to the right of the pressure chamber 106. The piston 108 has a circumferential groove for a seal 104 for sealing the pressure chamber 106. The piston 108 also has an internal bore in which the bolt 115 and the spring 113 are accommodated. The spring 113 is supported on the left side on a disk 114 which is inserted and caulked into the piston 108 in a first section of the bore, which has a larger diameter. The disk 114 can alternatively or additionally be fastened by other conventional securing components, such as a circlip. On the right side, the spring 113 is supported on a head 119 of the bolt 115. The bolt 115 is fastened in the adjusting piston 109 with a press fit 116. Alternatively or additionally, the bolt 115 could also be fastened in the adjusting piston 109 by means of an adhesive, solder or threaded connection.

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The piston has a fastening head 117 to which the brake pad 103 is attached. In order to prevent dirt from entering the cylinder 101, a scraper 102 is provided in the area of the opening of the cylinder 101.

When the brake lever (not shown) is operated, a piston in a master cylinder (not shown) is actuated, which presses hydraulic fluid into the hose 20. As a result, hydraulic fluid is introduced into the pressure chamber 106 via the inlet 107. As a result of this increase in pressure, the piston 108 in the cylinder 101 moves to the right against the action of the spring 113, so that the pad 103 rests on the rim 6 and braking can take place. Hydraulic fluid is fed to the brake cylinder 100' via the connecting hose 21 and the piston of this brake cylinder is actuated accordingly. If the pressure of the hydraulic fluid drops when the brake lever is released, the piston 108 is pushed back to its starting position by the spring 113 and the hydraulic fluid is pressed back into the hose 20.

For optimum braking effect, it is necessary to adjust the distance between the brake pad 103 and the rim 6. For example, if the brake pad 103 is worn, it is necessary to shift the basic position of the piston 108 to the right. In the brake cylinder according to the invention, this can be done simply by rotating the adjusting piston 109 via the thread 111 in the inner bore of the cylinder 101 and thus moving it in the axial direction. The adjusting piston 109 shifts the piston 108 to the right, in particular by means of the bolt 115. The tension of the spring 113 does not change in the process. Basically, all parts in the inner bore in the cylinder 101 are shifted in the axial direction relative to the cylinder 101.

To ensure that the brake functions safely at all times, it is important that the adjustment is not too far

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occurs that the adjusting piston 109 directs the inflow 107 into the

Pressure chamber 106 closes. Therefore, the retaining ring 112

arranged in such a way that it allows the adjustment of the

adjusting piston 109 is limited in such a way that it is always arranged to the left of the inlet 107.

Fig. 5 shows a perspective view of the brake cylinder 100 of Figures 3 and 4. The perspective view shows the preferred fastening device 300 according to the invention for the brake cylinder. The brake cylinder can be pivotally fastened to a frame part with the lugs 302 by means of a bolt (not shown in Fig. 5). In order to be able to carry out the pivoting movement quickly, a quick-release lever 301 is provided.

Fig. 6 shows a view of the brake cylinder 100 of Figures 3 to 5 from above, cut away in the area of the fastening arrangement 3 00. The preferred fastening device 3 00 according to the invention can best be described using this illustration.

In Fig. 6, the fastening device is only shown for the brake cylinder 100 shown on the left in Fig. 3, i.e. the left brake cylinder in the direction of travel of the bicycle. The fastening device 300 for the other brake cylinder is constructed accordingly, i.e. mirror-inverted.

The arrangement member 2'' is arranged on the rear frame of the bicycle frame or on the fork of the bicycle. The brake cylinder 100 is pivotably arranged on the arrangement member 2'' via the bolt 303. The bolt 303 engages both in an opening of the arrangement member 2'' and in an opening of the connecting member 302. To lock the pivoting movement around the axis determined by the bolt 303, an eccentric clamping bolt 3011 is provided, which is connected to a quick-release lever 301. The eccentric quick-release lever 3011 interacts with a screw 304,

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which is screwed into a threaded bore 305 formed in the arrangement member 2''. The preload caused by the interaction of the eccentric clamping bolt with the recessed head of the screw 3 05 can be preset by the screw 3 04.

Fig. 6 shows the brake cylinder 100 in a position in which the pivoting movement is locked. By moving the clamping lever 301 into a position parallel to the rim 6, the eccentric clamping bolt 3 011 releases the head of the screw 3 04 in such a way that the brake cylinder 100 can be pivoted into the assembly position about the axis determined by the bolts 303.

The fastening device 300 shown in Fig. 6 represents a particularly simple and reliable fastening of the brake cylinder 100 to the arrangement member 2'' and locking of the pivoting movement about the axis determined by the bolt 303. In particular, a releasable locking between the brake cylinder 100 and the arrangement member 2'' is provided.

In a further embodiment not shown, the brake cylinder is not arranged in front of the frame part and the arrangement element 2'' as shown in Fig. 6, as seen in the running direction 8 of the rim 6, but behind the arrangement element and the frame part as seen in the running direction of the rim. This embodiment is particularly suitable for applications in which the space in the knee area between the frame and the fork is limited. The embodiment corresponds to that shown in Fig. 6, but the running direction 8 points in the other direction. This embodiment also provides an integrated solution and a defined pivoting movement of the brake cylinder into the braking position. In this embodiment, due to the changed force distribution during braking, the eccentric clamping bolt must be suitably dimensioned in order to be able to absorb the forces occurring during braking.

Fig. 7 shows a section through a further embodiment of a brake cylinder according to the invention. The brake cylinder has a cylinder 201 with a bore in which a piston 208 is slidably arranged. To the left of the piston 208 there is a pressure chamber 206 which is connected via an inlet 207 to a hose 20 (not shown) which is connected to the master cylinder (not shown). The piston 208 has an inner piston part 2081 and an outer piston part 2082. The outer piston part 2082 has a bore with an internal thread. The inner piston part 2081 has an external thread which engages in the internal thread of the outer piston part 2082. By rotating the inner piston part 2081 relative to the outer piston part 2082 it is thus possible to change the length of the piston 208. The piston inner part 2081 has a non-circular inner bore in which a bolt 215 with a head is arranged in a rotationally fixed manner. The head has a cross section corresponding to the cross section of the bore. In the exemplary embodiment shown, the cross section of the piston inner part is hexagonal and the head of the bolt is a conventional hexagon. The spring 213 is supported on the head of the bolt 215. On the side of the piston inner part 2081 adjacent to the pressure chamber 206, the piston inner part 2081 has a short, larger bore into which a disk 214 is inserted and caulked. The disk 114 can alternatively or additionally be attached using other conventional securing components, such as a circlip. The spring 213 is supported on the disk 214. The bolt passes through an opening in the right-hand wall of the brake cylinder 200 which closes off the pressure chamber 206. The seal 2 05 seals the pressure chamber 2 06 from the environment. The piston inner part 2 081 has a groove in which the seal 204 is arranged to seal the pressure chamber 206. In order to prevent contamination of the interior of the cylinder 201, a scraper 202 is provided at the opening of the cylinder 2 01.

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An adjusting wheel 209 is attached to the bolt 215 with a press fit 216 in a rotationally fixed manner and is thus connected to the piston inner part 2081 in a rotationally fixed manner. Alternatively or additionally, the bolt 215 could also be connected to the adjusting wheel 209 via an adhesive, solder or threaded connection. The piston outer part 2082 has a fastening head 217 for fastening the brake pad (not shown). The brake pad engages with its outer ends in extensions 2013 of the brake cylinder. As a result, the brake pad is arranged in a rotationally fixed manner relative to the brake cylinder 200. The fastening head 217 has a surface 218 which secures the piston outer part 2082 against rotation relative to the brake pad and thus relative to the cylinder 201. By turning the adjusting wheel 209, the piston inner part 2081, which is connected to the adjusting wheel in a rotationally fixed manner, can be rotated relative to the piston outer part 2082, which is arranged essentially in a rotationally fixed manner with the brake cylinder 200. This changes the length of the piston 208 and the distance of the brake pad from the rim. Since the position of the piston 208 relative to the pressure chamber 206 does not change, the volume of the pressure chamber 206 remains unchanged.

The invention thus also relates to a brake cylinder for a hydraulic rim brake with a pressure chamber and a cylinder in which a piston is displaceably arranged, wherein the pressure chamber is displaceable together with the piston.

The invention thus also relates to a brake cylinder for a hydraulic rim brake or disc brake with a cylinder in which a piston is slidably arranged, wherein the length of the piston is adjustable.

The invention thus also relates to a brake cylinder for a hydraulic brake with a cylinder in which a piston is arranged to be displaceable in the axial direction of the cylinder, a pressure chamber, wherein the piston is displaceable in the cylinder by changing the volume of the pressure chamber, and

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an adjustment device with which the relative position of the

free end of the piston in axial direction with respect to the

cylinder is adjustable in such a way that the volume of the pressure chamber remains essentially unchanged.

The invention thus also relates to a brake cylinder as described above, in which the piston can be displaced in the axial direction together with the pressure chamber in the cylinder by actuating the adjusting device.

The invention thus also relates to a brake cylinder as described above, in which the adjusting device has an adjusting piston which is arranged displaceably in the cylinder such that the pressure chamber is located between the piston and the adjusting piston.

The invention thus also relates to a brake cylinder as described above, in which the cylinder has a section with an internal thread into which the adjusting piston with an external thread is screwed.

The invention thus also relates to a brake cylinder as described above, in which the adjusting piston has a hexagon socket in order to rotate the adjusting piston for adjustment in the cylinder.

The invention thus also relates to a brake cylinder as described above, in which the adjusting piston and the piston are connected to one another via a spring arrangement.

The invention thus also relates to a brake cylinder as described above, in which the distance between the inflow for hydraulic fluid into the pressure chamber and the adjusting piston in a position furthest away from the inflow is greater than the maximum possible adjustment path of the adjusting piston.

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The invention thus also relates to a brake cylinder as described above, in which the adjusting piston has a locking ring for limiting the adjustment path.

The invention thus also relates to a brake cylinder as described above, in which the adjusting piston is sealed with a seal relative to the pressure chamber and the piston is sealed with a seal relative to the pressure chamber.

The invention thus also relates to a brake cylinder as described above, in which the piston is adjustable in length.

The invention thus also relates to a brake cylinder as described above, in which the piston has a part which is arranged in a rotationally fixed manner with the adjusting device and a part which is arranged essentially in a rotationally fixed manner with the cylinder.

The invention thus also relates to a brake cylinder as described above, in which the piston has an inner piston part and an outer piston part which are arranged to be rotatable relative to one another via a thread, and in which the adjusting device has an adjusting wheel which is connected to the inner piston part in a rotationally fixed manner, wherein the outer piston part is arranged in the cylinder in a substantially rotationally fixed manner relative to the cylinder.

The invention thus also relates to a brake cylinder as described above, in which the adjusting wheel is preferably connected to a bolt in a rotationally fixed manner via a press fit, the bolt having a non-round head which engages in an opening in the inner piston part, which preferably has a cross section corresponding to the cross section of the head, in such a way that a rotationally locking connection is established between the adjusting wheel and the inner piston part.

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The invention thus also relates to a brake cylinder as described above, in which the piston outer part has a fastening head for receiving a brake pad, which is arranged essentially in a rotationally fixed manner to the cylinder, wherein the fastening head has a surface for securing the piston outer part against rotation relative to the pad.

The invention thus also relates to a brake cylinder as described above, in which the brake pad is arranged in end regions between extensions of the cylinder.

The invention thus also relates to a brake cylinder as described above, in which the piston is arranged to be displaceable in the axial direction in the cylinder against the force of a spring.

The invention thus also relates to a brake cylinder as described above, in which the piston has a cavity in which a bolt which is firmly connected to the adjusting device in the axial direction is accommodated, wherein the spring is supported with its pressure chamber-side end on the piston and with its other end on a head of the bolt.

The invention thus also relates to a brake cylinder as described above, in which the axial support of the spring on the piston is achieved by means of a disc.

The invention thus also relates to a hydraulic rim brake with at least one and preferably two of the brake cylinders described above.

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List of reference symbols

Frame part (fork leg or rear frame) Arrangement element Bolt (pivoting connection) Brake cylinder Connecting element Locking element Brake pad Rim Bolt (removable locking) Direction of rotation of the rim Hydraulic line Receptacle (for a brake pad)

20 Hose 21 Connecting hose 100 Brake cylinder 101 cylinder 1011 first section 1012 second part 102 Scraper 103 Brake pad 104 poetry 105 poetry 106 Printing room 107 Inflow 108 Pistons 109 Adjusting piston 110 Hexagon socket 111 thread 112 Retaining ring (to limit displacement) 113 Feather 114 disc 115 bolt 116 Press fit ··· ···· ·· ·# ·· ·· · &igr;··· · ·· · , ,
• · · ·······#· · ·» · _a · · ·&igr;
* * ··· ·· ·· · · · &phgr; ··· · · · · · i
• · · · ··· ··· · ···· · · ·&phgr;&phgr; · · &igr;
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I · · ♦

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117 Mounting head 119 Bolt head 200 Brake cylinder 201 cylinder 2013 Extension 202 Scraper 203 Brake pad 204 poetry 205 poetry 206 Printing room 207 Inflow 208 Pistons 2081 Piston inner part 2082 Piston outer part 209 Adjustment wheel 210 Hexagon (for driving the piston) 211 thread 213 Feather 214 disc 215 bolt 217 Mounting head 218 Surface (to prevent rotation of the piston outer part compared to the surface) 220 Adjustment device

Fastening device quick clamping lever eccentric clamping bolt

Connecting link bolt screw threaded hole

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Claims (41)

1. Brake cylinder ( 4 ; 100 , 100 '; 200 ) for a hydraulic rim brake with a receiving device ( 10 ) for a brake pad ( 5 ; 103 ), characterized by a connecting member ( 41 ; 302 ) for arranging the brake cylinder ( 4 ; 100 , 100 '; 200 ) on a frame part ( 1 ) so as to be pivotable about a pivot axis, the pivot axis being substantially orthogonal to the receiving device ( 10 ) for the brake pad ( 5 ; 103 ) and/or substantially orthogonal to the main axis of the brake cylinder ( 4 ; 100 , 100 '; 200 ). 2. Brake cylinder ( 4 ; 100 , 100 '; 200 ) according to claim 1, characterized in that the connecting member ( 41 ; 302 ) is designed as an extension of the brake cylinder ( 4 ; 100 , 100 '; 200 ). 3. Brake cylinder ( 4 ; 100 , 100 '; 200 ) according to one of the preceding claims, characterized in that the connecting member ( 41 ; 302 ) has an opening in which a bolt ( 3 ; 303 ) can be received for the pivotable arrangement of the brake cylinder ( 4 ; 100 , 100 '; 200 ) on the frame part. 4. Brake cylinder ( 4 ; 100 , 100 '; 200 ) according to one of the preceding claims, characterized in that the brake cylinder ( 4 ; 100 , 100 '; 200 ) is hydraulically actuated. 5. Brake cylinder ( 4 ; 100 , 100 '; 200 ) according to one of the preceding claims, characterized in that the brake cylinder ( 4 ; 100 , 100 '; 200 ) has a connecting member ( 41 ; 302 ) in which a bolt ( 3 ; 303 ) is received, which is in engagement with an arrangement member ( 2 ; 2 '; 2 ") arranged on the frame part ( 1 ). 6. Brake cylinder ( 4 ; 100 , 100 '; 200 ) according to one of the preceding claims, characterized in that the brake cylinder ( 4 ; 100 , 100 '; 200 ) has a releasable locking device ( 300 ) of the pivoting movement. 7. Brake cylinder ( 4 ; 100 , 100 '; 200 ) according to one of the preceding claims, characterized in that the brake cylinder ( 4 ; 100 , 100 '; 200 ) has a return spring which prestresses the brake cylinder ( 4 ; 100 , 100 '; 200 ) against the arrangement member ( 2 ; 2 '; 2 ") into a braking position. 8. Brake cylinder ( 100 ; 200 ) according to one of the preceding claims for a hydraulic brake with
a cylinder ( 101 ; 201 ) in which a piston ( 108 ; 208 ) is arranged to be displaceable in the axial direction of the cylinder ( 101 ; 201 ),
a pressure chamber ( 106 ; 206 ), wherein the piston ( 108 ; 208 ) is displaceable in the cylinder ( 101 ; 201 ) by changing the volume of the pressure chamber ( 106 ; 206 ), and
an adjusting device ( 120 ; 220 ) with which the relative position of the free end of the piston ( 108 ; 208 ) in the axial direction with respect to the cylinder ( 101 ; 201 ) can be adjusted such that the volume of the pressure chamber ( 106 ; 206 ) remains substantially unchanged. 9. Brake cylinder ( 100 ) according to claim 8, characterized in that by actuating the adjusting device ( 120 ) the piston ( 108 ) can be displaced in the axial direction together with the pressure chamber ( 106 ) in the cylinder ( 101 ). 10. Brake cylinder ( 200 ) according to claim 8, characterized in that the piston ( 208 ) is adjustable in length. 11. Rim brake, in particular for bicycles, with one or two brake cylinders ( 4 ; 100 , 100 '; 200 ) according to one of the preceding claims. 12. Rim brake, especially for bicycles,
with two brake cylinders ( 4 ; 100 , 100 '; 200 ) for attachment to frame parts ( 1 ) which enclose a wheel rim ( 6 ) between them,
characterized in that
at least one brake cylinder ( 4 ; 100 , 100 '; 200 ) can be arranged on the frame part ( 1 ) so as to be pivotable about an axis which runs essentially parallel to the course of the frame part ( 1 ) at the fastening point. 13. Rim brake, especially for bicycles,
with two brake cylinders ( 4 ; 100 , 100 '; 200 ) for fastening to frame parts ( 1 ) which enclose a wheel rim ( 6 ) between them and have a receiving device ( 10 ) for receiving a brake pad ( 5 ; 103 ),
characterized in that
at least one brake cylinder ( 4 ; 100 , 100 '; 200 ) can be arranged on the frame part ( 1 ) so as to be pivotable about an axis which runs essentially orthogonal to the receiving device ( 10 ) and/or essentially orthogonal to the main axis of the brake cylinder ( 4 ; 100 , 100 '; 200 ). 14. Hydraulic rim brake for bicycles with two brake cylinders ( 4 ; 100 , 100 '; 200 ) enclosing the wheel rim ( 6 ) between them, characterized in that the brake cylinders ( 4 ; 100 , 100 '; 200 ) are each arranged to be pivotable about an axis which runs essentially parallel to a frame part ( 1 ) on which the respective brake cylinder ( 4 ; 100 , 100 '; 200 ) is arranged to be pivotable. 15. Rim brake according to one of claims 11 to 14, characterized in that the brake cylinder or cylinders ( 4 ; 100 , 100 '; 200 ) are arranged in front of or behind the frame part ( 1 ) as seen in the running direction ( 8 ) of the rim ( 6 ). 16. Rim brake according to one of claims 11 to 15, characterized in that both brake cylinders ( 4 ; 100 , 100 '; 200 ) are arranged pivotably. 17. Rim brake according to one of claims 11 to 16, characterized in that the pivot axis is arranged between the frame part ( 1 ) and the brake cylinder ( 4 ; 100 , 100 '; 200 ) as seen in the running direction ( 8 ) of the rim ( 6 ). 18. Rim brake according to one of claims 11 to 17, characterized in that the brake cylinder or cylinders ( 4 ; 100 , 100 '; 200 ) are positively received in a braking position by the associated arrangement member ( 2 , 2 ') (for power transmission). 19. Rim brake in particular according to one of claims 11 to 18, characterized in that the brake cylinder or cylinders ( 4 ; 100 , 100 '; 200 ) can be pivoted from a mounting position into a defined braking position. 20. Brake cylinder ( 100 ; 200 ) Brake cylinder for a hydraulic rim brake with a pressure chamber ( 106 ; 206 ) and a cylinder ( 101 ; 201 ) in which a piston ( 108 ; 208 ) is displaceably arranged, wherein the pressure chamber ( 106 ; 206 ) is displaceable together with the piston ( 108 ; 208 ). 21. Brake cylinder ( 100 ; 200 ) for a hydraulic rim brake or disc brake with a cylinder ( 101 ; 201 ) in which a piston ( 108 ; 208 ) is displaceably arranged, wherein the length of the piston ( 108 ; 208 ) is adjustable. 22. Brake cylinder ( 100 ; 200 ) for a hydraulic brake with
a cylinder ( 101 ; 201 ) in which a piston ( 108 ; 208 ) is arranged to be displaceable in the axial direction of the cylinder ( 101 ; 201 ), and
a pressure chamber ( 106 ; 206 ), wherein the piston ( 108 ; 208 ) is displaceable in the cylinder ( 101 ; 201 ) by changing the volume of the pressure chamber ( 106 ; 206 ),
characterized by an adjusting device ( 120 ; 220 ) with which the relative position of the free end of the piston ( 108 ; 208 ) in the axial direction with respect to the cylinder ( 101 ; 201 ) can be adjusted such that the volume of the pressure chamber ( 106 ; 206 ) remains substantially unchanged. 23. Brake cylinder ( 100 ) according to claim 22, characterized in that by actuating the adjusting device ( 120 ) the piston ( 108 ) can be displaced in the axial direction together with the pressure chamber ( 106 ) in the cylinder ( 101 ). 24. Brake cylinder ( 100 ) according to claim 22 or 23, characterized in that the adjusting device ( 120 ) has an adjusting piston ( 109 ) which is arranged displaceably in the cylinder ( 101 ) such that the pressure chamber ( 106 ) is located between the piston ( 108 ) and the adjusting piston ( 109 ). 25. Brake cylinder ( 100 ) according to claim 24, characterized in that the cylinder ( 101 ) has a section ( 1011 ) with an internal thread into which the adjusting piston ( 109 ) is screwed with an external thread ( 111 ). 26. Brake cylinder ( 100 ) according to claim 25, characterized in that the adjusting piston ( 109 ) has a hexagon socket ( 110 ) in order to rotate the adjusting piston ( 109 ) for adjustment in the cylinder ( 101 ). 27. Brake cylinder ( 100 ) according to one of claims 23 to 26, characterized in that the adjusting piston ( 109 ) and the piston ( 108 ) are connected to one another via a spring arrangement. 28. Brake cylinder ( 100 ) according to one of claims 23 to 27, characterized in that the distance between the inflow ( 107 ) for hydraulic fluid into the pressure chamber ( 106 ) and the adjusting piston ( 109 ) in a position furthest away from the inflow ( 107 ) is greater than the maximum possible adjustment path of the adjusting piston ( 109 ). 29. Brake cylinder ( 100 ) according to one of claims 23 to 28, characterized in that the adjusting piston ( 109 ) has a locking ring ( 112 ) for limiting the adjustment path. 30. Brake cylinder ( 100 ) according to one of claims 23 to 29, characterized in that the adjusting piston ( 109 ) is sealed with a seal ( 105 ) relative to the pressure chamber ( 106 ) and the piston ( 108 ) is sealed with a seal ( 104 ) relative to the pressure chamber ( 106 ). 31. Brake cylinder ( 200 ) according to claim 22, characterized in that the piston ( 208 ) is adjustable in length. 32. Brake cylinder ( 200 ) according to claim 22 or 31, characterized in that the piston ( 208 ) has a part arranged in a rotationally fixed manner with the adjusting device ( 220 ) and a part arranged in a substantially rotationally fixed manner with the cylinder ( 201 ). 33. Brake cylinder ( 200 ) according to claim 22, 31 or 32, characterized in that the piston ( 208 ) has an inner piston part ( 2081 ) and an outer piston part ( 2082 ) which are arranged to be rotatable relative to one another via a thread ( 211 ), and in that the adjusting device ( 220 ) has an adjusting wheel ( 209 ) which is connected to the inner piston part ( 2081 ) in a rotationally fixed manner, the outer piston part ( 2082 ) being arranged in the cylinder ( 201 ) in a substantially rotationally fixed manner relative to the cylinder ( 201 ). 34. Brake cylinder ( 200 ) according to claim 33, characterized in that the adjusting wheel ( 209 ) is connected to a bolt ( 215 ) in a rotationally fixed manner, preferably via a press fit ( 216 ), the bolt ( 215 ) having a non-round head ( 210 ) which engages in an opening of the piston inner part ( 2081 ), which preferably has a cross section corresponding to the cross section of the head, in such a way that a rotationally locking connection is established between the adjusting wheel ( 209 ) and the piston inner part ( 2081 ). 35. Brake cylinder ( 200 ) according to claim 33 or 34, characterized in that the piston outer part ( 2082 ) has a fastening head ( 217 ) for receiving a brake pad, which is arranged substantially rotationally fixed to the cylinder ( 201 ), wherein the fastening head ( 217 ) has a surface ( 218 ) for securing the piston outer part ( 2082 ) against rotation relative to the pad. 36. Brake cylinder ( 200 ) according to claim 35, characterized in that the brake pad is arranged in end regions between extensions ( 213 ) of the cylinder ( 201 ). 37. Brake cylinder ( 100 ; 200 ) according to one of claims 22 to 36, characterized in that the piston ( 108 ; 208 ) is arranged to be displaceable in the axial direction in the cylinder ( 101 ; 201 ) against the force of a spring ( 113 ; 213 ). 38. Brake cylinder ( 100 ; 200 ) according to claim 37, characterized in that the piston ( 108 ; 208 ) has a cavity in which a bolt ( 115 ; 215 ) which is firmly connected in the axial direction to the adjusting device ( 120 ; 220 ) is accommodated, the spring ( 113 ; 213 ) being supported with its pressure chamber-side end on the piston ( 108 ; 208 ) and with its other end on a head ( 119 ; 219 ) of the bolt ( 115 ; 215 ). 39. Brake cylinder ( 100 ; 200 ) according to one of claims 22 to 38, characterized in that the axial support of the spring ( 113 ; 213 ) on the piston ( 108 ; 208 ) is effected by means of a disk ( 114 ; 214 ). 40. Hydraulic rim brake with at least one and preferably two brake cylinders ( 100 ; 200 ) according to one of claims 22 to 39. 41. Hydraulic disc brake with a brake cylinder ( 100 ; 200 ) according to one of claims 22 to 39.