WO1990013470A1

WO1990013470A1 - Hydraulic rim brake on a bicycle

Info

Publication number: WO1990013470A1
Application number: PCT/CH1990/000121
Authority: WO
Inventors: Ueli Eser
Original assignee: Ueli Eser
Priority date: 1989-05-03
Filing date: 1990-05-03
Publication date: 1990-11-15

Abstract

The hydraulic lines (8a, 8b) for the front and rear brakes are lodged in the handlebar (30), the steering head (31) and the steering tube. The line for the front brake emerges through the head of the front wheel fork. To simplify the assembly of the lines (8a, 8b), the steering head (31) has a removable cover (32). The handlebar (30) is clamped to a U-shaped bend (34) between the cover (32) and a support body (35).

Description

Hydraulic rim brake on a bike

The invention relates to a hydraulic rim brake on a bicycle.

In the prior art, mechanical rim brakes with cables for the front wheel and rear wheel are generally known in bicycles. Also known is a bicycle with a hydraulic rim brake, which has a transmitter, two receivers and hose lines filled with liquid mineral oil for the front wheel brake and the rear wheel brake. The brake pads are moved in pairs with the slave cylinders. To attach the slave, they are attached to the ends of a U-shaped bracket, which are attached in front of or behind a fork, similar to the mechanical brakes. According to a likewise known embodiment, the slave cylinders with brackets are soldered to the frame or the fork. Compared to the cable brake, the hydraulic brake has advantages. Since the rope friction is completely eliminated, the loss in efficiency is much smaller. In addition, the dosage of the braking force is better and the braking force is greater with the same hand force. As with brakes with a cable, the laying of the brake lines can be improved from a functional and aesthetic point of view.

The invention has for its object to provide a hydraulic rim brake of the type mentioned, which is particularly suitable for racing bicycles and which can nevertheless be manufactured inexpensively and meets the high safety requirements. The brake according to the invention should be structurally simple and enable an aesthetically pleasing structure. The object is achieved by the invention according to claim 1.

In the rim brake according to the invention, the lines are completely laid inside the handlebar, the stem and the head tube and are not visible from the outside here. Since the lines here do not offer any air resistance when driving, this improves the aerodynamics of the bicycle. Soldering parts or openings in the top tube for laying the line for the rear wheel brake are dispensed with, since this line can be drawn directly from the head tube into the interior of the down tube. This extensive internal routing of the lines also makes bike cleaning simplified and damage to the cables due to external influences avoided.

Further advantageous features result from the dependent claims and the description.

Through the development according to claims 15 and 16, a simple adjustment of the brake and a soft pressure point is achieved.

An embodiment of the invention is explained in more detail below with reference to the drawings. Show it:

1 shows a part of a partially sectioned front wheel fork with the brake according to the invention and schematically a front wheel,

Fgi. 2 shows a view of a brake pad and a guide plate,

3 shows a partial section along the line III-III in FIG. 1,

4 shows a section through a handlebar stem,

5 is a view of part of the handlebar stem, 6 is a partial section through a brake valve and part of the handlebar,

7 shows a section through a brake valve according to a variant,

8 a section of part of a front wheel fork and schematically a part of the front wheel,

9 in section a slave inserted in a front wheel fork according to a further variant,

10 in section a slave inserted in a wheel fork according to a further variant,

11a shows a section through a handlebar stem according to a variant,

11b shows a plan view of the handlebar stem according to FIG. 11a, and

12a-12c show schematic views of a further variant of the handlebar and the handlebar stem.

On the fork 2 shown in Fig. 2, a front wheel 1 with a tire la, a rim 1b and spokes lc is attached in the usual manner. To the left and right of the rim 1b there are brake pads 3 and 4, the braking surfaces 3a and 4a of which are each a few millimeters apart, for example 2 mm from the rim. point. The brake pads 3 and 4 are made of the usual material for this. In order to brake the wheel 1, only the brake pad 3 is moved to the right in FIG. 1. As soon as the braking surface 3a hits the brake, the wheel 1 is already braked somewhat. The braking effect is increased by moving the brake pad 3 further to the right and displacing the rim 1b against the brake pad 4. As soon as both brake pads 3 and 4 rest on the rim, the braking force can be increased to the maximum. An embodiment is also conceivable in which both brake pads are moved together.

The distance between the brake pad 4 and the rim 1b can be adjusted with an Allen key. For this purpose, an adjusting screw 10 provided with an external thread, which engages with a head 11 in a recess 4b of the brake pad, is screwed in one or the other direction in a sleeve 9 provided with a corresponding internal thread. The sleeve 9 is inserted into a bore 2c of a fork arm 2b and welded to arm 2b or connected by brazing. A guide plate 6 is welded onto the inside of the arm 2b. This plate 6 has two guide pins (not visible here) on the front, which are inserted into corresponding through-holes in the brake block 4. These guide pins enable the brake pad 4 to be moved in the longitudinal direction of the adjusting screw 10 and at the same time to be held on the plate 6. Wear of the brake pad 4 can be achieved by adjusting the brake pad accordingly 4 can be compensated at pin 10.

The brake block 3 which is movable during braking is slidably fastened on a guide plate 5, as shown in FIGS. 2 and 3, which plate is welded onto the inside of the fork arm 2a. This plate 5 has protruding guide pins 5a at the front which correspond to the pins of the guide plate 6. The guide pins 5a are inserted into through bores 3c of the brake block 3. The pins 5a are dimensioned such that the brake pad 3 can never slide off the plate 5 even during the braking process.

The slave 7 has a housing with a sleeve 7b and a cover 7a and a piston 7h which is displaceably guided in the sleeve 7b. The piston 7h is sealed with two sealing rings 7c against the sleeve 7b. As can be seen from Fig. 1, the sleeve 7b is inserted into a continuous and circular bore 2d of the arm 2a. At the inner end, the sleeve 7b engages in a recess in the guide plate 5. The guide plate 5 and the sleeve 7b are welded to the arm 2a in such a way that this arm 2a is not weakened by the bore 2d. The cover 7a is firmly connected to the sleeve 7b, for example by brazing. The pressure chamber of the slave 7 is connected to the line hose 8a via a bore 71. A nipple 7k is attached to the sleeve 7b for fastening the line hose 8a. To return the piston 7h, a spring 7f and a retaining pin are in a bore of the piston 7h 7e used. The spring 7f is limited in its movement on a head of the holding pin 7e and on a plate 7g which is firmly connected to the piston 7h. The holding pin 7e is detachably fastened to the inside of the cover 7a by a screw 7d which can be operated from the outside. If the piston 7h is shifted to the right during the braking process, the spring 7f is compressed and brings the piston 7h back into the rest position when the pressure of the brake fluid decreases. Necessary if the piston 1 is removed, the piston can be removed to the front after loosening the screw 7d.

Shortly after the nipple 7k, the hose line 8a leads through a bore 2e into the interior of the fork 2 and from there inside and therefore not visible from the outside through the frame, the handlebar stem 13 (FIG. 4) and as in FIG. 6 shown by the handlebar 17. The line hose 8a leaves the handlebar 17 through a bore 7a and is connected at the upper end to the transmitter 19 with a nipple 18i.

To attach the handlebar stem 13 to the frame of the bicycle, a conical part 16 is provided, which with a screw

14 is drawn between two clamping arms 13b, which in this case deflect laterally and clamp the handlebar stem 13 in the frame. The head of the screw 14 is with the cover removed

15 accessible from above. 5 shows, the conical part 16 has two passages 16b, through which two hose lines 8a and 8b are drawn. The hose line 8a leads down to the rim brake for the front wheel and the hose line 8b also inside the frame to the rim brake for the rear wheel. The handlebar stem 13 has a semicircular recess 13c at the front end, in which the handlebar is inserted and fastened in a known manner .

The sensor 19 shown in FIG. 6 has a sleeve-shaped housing 19e which is firmly inserted in a corresponding cylindrical recess in the housing 18d. The housing 19e and the piston 19d are sealed off from one another with a rubber-elastic sealing ring 19f. A compression spring 19g, which is supported on the housing 18d and on the piston 19d, ensures the return of the piston 19d. To initiate a braking operation, the hand lever 18a is pivoted about a pivot axis 18c in the usual way, as a result of which the rubber-elastic body 19c in FIG. 6 presses the piston 19d downward against the restoring force of the spring 19g. The pressure arising in the brake fluid is passed on to the slave 7 via the hose line 8a. A threaded rod 19b is attached to the rubber-elastic body 19c, which is pivotably mounted in a body 19a, and which can be adjusted in its longitudinal direction via an opening 18b in the handle 18a and thus the rubber-elastic body 19c. As can be seen, the distance between the brake pad 3a and the rim 1b can be adjusted by turning the threaded rod 19b. All that is required is a screwdriver, making it a very simple one and there is a precise setting option. To vent the pressure chamber of the transmitter 19, a closure body 18g is loosened, which is screwed into a passage 18f in the housing 18d.

On the handlebar 17, a brake fitting is provided for the rim brake of the rear wheel, which is connected to the hose line 8b and is designed in exactly the same way as that shown in FIG. 6. The statements made above for the rear rim brake also apply. 1 to 3 were made. However, the fork 2 is the approximately horizontal fork of the bicycle frame. As such, it would be possible to operate both rim brakes with a single brake fitting 18. For safety reasons, however, it is advisable to use separate and self-contained hydraulic systems for the front rim brake and the rear rim brake.

An important advantage of the invention is the good metering ability of the braking power and the avoidance of unintentional over-braking. On the one hand, the rubber-elastic body 19c contributes to this, which ensures a soft pressure point even when the brakes are applied brusquely. On the other hand, it is the movement sequence of the brake pad 3 or the rim 1b explained with reference to FIG. 1 that enables an approximately continuous increase in the braking power. The rubber-elastic body 19c and the movement sequence mentioned work together and are coordinated with each other, which results in a particularly good braking effect.

In the brake fitting shown in section in FIG. 7, a filling device 180 is provided, via which the brake fluid can be filled and at the same time vented. A sleeve 180a with an internal thread is inserted into the mouth of a passage 181a of a fitting housing 181. The passage 181a leads to the pressure chamber 181b of the transmitter, which can be designed as shown in FIG. 6. A body 180b is screwed into the sleeve 180a and has a conical surface 180c at the front, which cooperates with a corresponding conical sealing surface 181c of the housing 181. The body 180b also has a transverse bore 18Od and a passage 180e which extends in the longitudinal direction and into which a hexagon key 182 with a continuous inner channel 182a can be inserted.

In order to fill in brake fluid, the hexagon socket key 182 is inserted into the passage 180e and a hose line (not shown here) is connected to the free end 182b, which leads to a container containing brake fluid. When the aforementioned container is raised, brake fluid flows through the passage 182a into the transverse bore 180d and from there between the surfaces 180c and 181c into the passage 181a and finally into the lines and the slave on the front wheel or rear wheel. The when filling the brake fluid Displaced air escapes through the brake fluid upwards and finally through passage 182a to the outside. When enough brake fluid has been filled in, the body 180b is screwed in with the key 182 in the sleeve 180a until the conical surface 180c bears against the sealing surface 181c. 7 can be designed according to FIG. 6, however, the closure body 18g and the passage 18f are unnecessary.

8 shows a further advantageous mounting of the brake pad 4. A sleeve 201 with a funnel-shaped extension 201b is inserted into bores 200a and 200b of a wheel fork 200. The sleeve 201 has an internal thread, into which a set screw 202 is screwed, which engages with a head 202a in a recess 4a of the brake pad 4. A plate 203 is welded to the fork 200 and has a bore 203a into which a spring washer 204 is inserted. When braking, the brake pad 4 is moved against the spring force of the disk 204 against the outer surface 203b of the plate 203, a gap 203c being partially or completely eliminated. The head 202a is displaceable in the recess 4a in accordance with this movement. This design of the brake pad holder has the further advantage that it alone prevents overly brusque braking. The funnel-shaped extension 201b has the advantage that the set screw 202 can also be operated with an articulated Allen key if it is bad on the rear wheel due to the pedal device is accessible. In the case of the front wheel brake, the shoulder 201b can be omitted.

The slave 300 shown in FIG. 9 has a housing 300a with a cover 300b soldered on, which is inserted together with the piston 301 into a sleeve 302 which is fastened in bores 303a of a fork 303. At the front end, the housing 300a has a groove 300c on the outside, into which a snap ring 300d is inserted, which detachably fixes the slave 300 in the fork 303. A holding pin 304 is fixed at one end 304a by spot welding to the cover 300b and engages with the other end 300c in a recess 301b of the piston 301. A compression spring, not shown here, is supported on the holding pin 304 and on a disk 301b connected to the piston 301 and ensures that the piston 301 is returned after the braking process. Further parts of the slave 300 are a nipple 304 for the connection of the brake line and sealing rings 305 and 306, not shown here, and a ring 307. The slave 300 is characterized by a particularly easy-to-assemble construction.

Due to its particularly short construction, the slave 400 shown in FIG. 10 is particularly suitable for the rear wheel brake. In contrast to the slave 300, a piston 401 is provided here, which has a turn 401b on the outside at the rear end, which ensures the passage of the brake fluid from the pressure chamber 403 to the nipple 402. A variant of a handlebar stem 500 is shown in FIGS. 11a and 11b. This has an upper part 501, which is detachably fastened to a lower part 504 by cylinder screws 502 and 503. The handlebar, not shown here, is clamped between the pliers-shaped ends 501a and 504a. Recesses 501b and 504b in the upper part 501 and lower part 504 form a channel 505 into which the brake line (not shown here) is drawn. The brake line emerging at a front opening 505a of the channel 505 is drawn into the handlebar rod through a bore and connected to the transmitter as shown in FIG. 6. The parts 501 and 504 are preferably made of aluminum.

Figures 12a to 12c show a handlebar 30 and a handlebar stem 31, in which the lines 8a and 8b for the front and rear brakes are also completely laid inside. The brake fittings not shown here can be designed as shown in FIG. 6. As shown in FIGS. 12b and 12c, the link 30 has a semicircular bend 34 in the middle, which bears on a support body 35 at the bottom and on a cover 32 at the top. The handlebar 30 is clamped between the cover 32 and the support body 35 with a screw 36 which engages in a clamping part 37 for fastening the handlebar stem. The lines 8a and 8b, not shown here, pass through openings 38 below the cover 32 out of the handlebar 30 and through a pipe piece 38 inserted into the support body 35 into a sleeve 39 in which the lines 8a and 8b are wound into spirals 40 and 41 as shown in FIG. 12a. These spirals 40 and 41 form a line supply with which changes in length when steering can be compensated for. The sleeve 39 is open at the top and bottom and inserted with the tube piece 38 into the head tube of the bicycle frame. The cover 32 and the support body 35 are additionally secured with two further screws 42.

The cover 32 has a recess 43 into which a device 33 is inserted, which shows the driver, for example, the speed, the distance traveled and the average speed. Such devices are generally known and generally have an electrical cable that leads to a sensor attached to the front wheel fork. In the embodiment of the handlebar stem according to the invention, this cable can now also be laid down through the interior of the handlebar stem 31 into the front wheel fork. Through an opening in the fork, the cable is led outside to the sensor. If the device 33 is inserted from below into the cover 32, this is much better protected against theft than before.

Despite the considerable advantages of the hydraulic rim brake according to the invention, this can be seen with relatively few, simple and robust components. A rim brake was thus created which not only takes excellent account of the safety and driving requirements, but is also inexpensive and extremely reliable due to its simple and robust design.

Claims

Patent claims

1. Hydraulic rim brake on a bicycle, with a transmitter and a slave and with lines for a brake fluid, characterized in that the lines (8a, 8b) in the handlebar (17, 30), in the handlebar stem (13, 31, 500 ) and runs in the control tube (20).

2. Hydraulic rim brake according to claim 1, characterized gekenn¬ characterized in that the. Handlebar rod (17) in the brake armatures (18) each has an opening (17a) and the lines (8a, 8b) pass through one of these openings (17a).

3. Hydraulic rim brake according to claim 1 or 2, characterized in that the front wheel fork (2) has an opening (2e) through which the line (8a) for the front wheel brake exits the front wheel fork (2).

4. Hydraulic rim brake according to one of claims 1 to 3, characterized in that the handlebar stem (13, 500) has an interior passage (13a, 13d, 504) and the lines (8a, 8b) are pulled through this passage.

5. Hydraulic rim brake according to one of the claims

1 to 4, characterized in that the handlebar stem (31, 500) has a detachable cover (32, 501) for the assembly of the lines (8a, 8b).

6. Hydraulic rim brake according to claim 5, characterized gekenn¬ characterized in that with the cover (32) of the handlebar (30) is fixed by clamping on the stem (31).

7. Hydraulic rim brake according to claim 5 or 6, characterized in that in the cover (32) a device (33), for example for displaying the driving speed, is used.

8. Hydraulic rim brake according to one of the claims

1 to 7, characterized in that the handlebar (30) is clamped under the cover (32) along a semicircular bend (34).

9. Hydraulic rim brake according to one of the claims

1 to 8, characterized in that on the inside of at least one arm (2a) of the front wheel fork (2) a guide plate (5) is fixed, and that this guide plate (5) a brake pad (3) is guided during the braking process.

10. Hydraulic rim brake according to claim 1, characterized gekenn¬ characterized in that the piston (19d) of the transmitter (19) is movable approximately vertically to the course of the handlebar (17).

11. Hydraulic rim brake according to claim 1, characterized gekenn¬ characterized in that the brake armature (18) has a housing (18d) manufactured in the Spritzgussver¬ method, and that this housing with screws (18a) screwed directly to the handlebar (17) is.

12. Hydraulic rim brake according to claim 10, characterized in that between the piston (19d) and the hand lever (18a) a rubber-elastic body (19d) is angeord¬ net.

13. Hydraulic rim brake according to claim 12, characterized in that the rubber-elastic body (19c) on the hand lever (18a) is adjustably attached.