SHOCK ABSORBER FOR A BICYCLE

Abstract

A shock absorber for a bicycle including a damping system, the damping system including a damping chamber partitioned in a first chamber and a second chamber by a movable piston, a low-speed throttle for the low-speed range, and a high-speed throttle for the high-speed range, the high-speed throttle having a throttle valve biased to a closed position by a spring device. An effective flow cross-section for the high-speed throttle is adjustable.

Claims

1. A shock absorber for an at least partially muscle-powered two-wheeled vehicle, and in particular a bicycle comprising: at least one damping system, the damping system comprising at least one damping chamber partitioned in a first chamber and a second chamber by means of a movable piston; and at least one low-speed throttle for the low-speed range; and at least one high-speed throttle for the high-speed range; the high-speed throttle comprising at least one throttle valve biased to a closed position by means of a spring device; and at least one effective flow cross-section for the high-speed throttle is adjustable.

2. The shock absorber according to claim 1, wherein at least three different effective flow cross-sections of the high-speed throttle are adjustable.

3. The shock absorber according to claim 1, wherein the high-speed throttle shows an adjustable flow cross-section in at least one flow duct.

4. The shock absorber according to claim 1, wherein the free flow cross-section is adjustable by means of a movable adjusting unit.

5. The shock absorber according to claim 4, wherein the adjusting unit comprises an axially movable lance element and/or a positioning body adjustable transverse to the flow duct.

6. The shock absorber according to claim 1, wherein the free flow cross-section is at least partially configured at an adjustable flow valve comprising the at least one flow duct.

7. The shock absorber according to claim 5, wherein a plurality of flow ducts is provided, and at least one flow duct can be at least partially covered by the positioning body.

8. The shock absorber according to claim 1, wherein a spring constant of the spring device of the throttle valve is changeable, wherein a spring force of the spring device of the throttle valve is changeable, and wherein, in particular the spring force-loaded throttle valve is disposed in series or in parallel to the flow valve.

9. The shock absorber according to claim 1, wherein the throttle valve is configured as a shim valve and comprises at least one shim unit, and wherein the spring device acts on at least one shim unit of the shim valve.

10. The shock absorber according to claim 1, wherein the spring device is disposed off-center on a shim unit, or wherein the spring device is disposed at the shim unit pivotable around an eccentric axis, and wherein a spring constant is variable by way of relative motion relative to the shim unit.

11. The shock absorber according to claim 1, wherein the throttle valve and/or the flow valve is configured inside a damper housing of the damping system.

12. The shock absorber according to claim 1, wherein the throttle valve and/or the flow valve is disposed outside of a damper housing of the damping system.

13. The shock absorber according to claim 1, wherein the damping system comprises a magnetorheological fluid and is controlled by way of a magnetic field.

14. The shock absorber according to claim 1, wherein the low-speed throttle is adjustable, and wherein in particular the low-speed throttle is adjustable together with the high-speed throttle.

15. The shock absorber according to claim 1, wherein low-speed throttles and high-speed throttles are provided for the compression stage and the rebound stage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Further advantages and features of the present invention can be taken from the exemplary embodiment which will be described below with reference to the enclosed figures.

[0040] The figures show in:

[0041] FIG. 1 a schematic illustration of a mountain bike;

[0042] FIG. 2 a schematic illustration of a shock absorber according to the invention;

[0043] FIG. 3 an adjustment option for adjusting a flow valve of the damping system according to FIG. 2;

[0044] FIG. 4 a top view of a throttle valve of the shock absorber according to FIG. 2;

[0045] FIG. 5 a sectional side view of the throttle valve according to FIG. 4; and

[0046] FIG. 6 a bottom view of an alternative throttle valve of the shock absorber according to FIG. 2;

[0047] FIG. 7 various characteristic curves.

DETAILED DESCRIPTION

[0048] FIG. 1 illustrates a simplistic side view of a bicycle 100, which in this case is a mountain bike. The bicycle 100 is at least partially muscle-powered and may be provided with an electric auxiliary drive.

[0049] The mountain bike or bicycle 100 is provided with a front wheel 51 and a rear wheel 52, each having rims 61. Tires 60 are mounted to the rims. Furthermore, the bicycle 100 comprises a frame 53, a sprung front fork 54 and a rear wheel damper 55.

[0050] FIG. 2 is a simplistic view of a shock absorber 50 for the bicycle 100 in FIG. 1. The shock absorber 50 may be both a front wheel fork or a rear wheel damper.

[0051] Presently, the damping system 1 comprises a damper housing 6 in which a damping chamber 2 is disposed which is partitioned into a first chamber 3 and a second chamber 4 by way of a movable piston 5. To compensate for the entering volume of the piston rod, an equalizing chamber 7 having a dividing piston 8 is provided.

[0052] The first chamber 3 and the second chamber 4 are interconnected through flow ducts which are presently shown externally for better clarity. Alternately, it is possible to provide external and/or internal flow ducts. Basically, flow ducts may be accommodated internally in the piston as is shown e.g. in FIG. 6.

[0053] In the flow path, at least one low-speed throttle 30 and a high-speed throttle 10 are provided which are presently connected in parallel. Both the low-speed throttle 30 and the high-speed throttle 10 are adjustable.

[0054] The high-speed throttle 10 comprises for the same flow direction, two series-connected valves, a throttle valve 13 and a flow valve 19, both of which may be adjustable.

[0055] The flow valve 19 in FIG. 2 provides for adjusting the active flow cross-section to thereby vary the characteristic curve in the high-speed range as desired.

[0056] The throttle valve 13 is configured as a one-way valve, comprising a shim valve 20 having at least one shim unit 21. The throttle valve 13 is biased to the closed position by a spring device 11.

[0057] The closed position 12 is illustrated in FIG. 2. For example, a ball biased by a spring device 11 closes a flow duct. Other throttle valves such as shim valves etc. are likewise possible.

[0058] FIG. 3 shows a schematic design option for the flow valve 19 in FIG. 2. Here, a flow duct 15 is provided in which an adjusting unit 16 is disposed adjustable in the axial direction. The adjusting unit 16 is configured as somewhat like a lance element 17 showing a tapered, pointed front end element which partially projects into an opening of a wall so that it provides only part of the possible flow cross-section 14. As the adjusting unit 16 is inserted further into the opening, the remaining flow cross-section decreases, and vice versa. This configuration provides an effective way of adapting and adjusting the high-speed characteristic curve.

[0059] The FIGS. 4 and 5 show a schematic illustration of a throttle valve 13, FIG. 4 showing a top view and FIG. 5, a sectional side view.

[0060] This throttle valve 13 comprises a shim valve and has a shim unit 21. The shim unit 21 is a circular spring leaf and is centrally fixed to the axle 22. Therefore, the shim unit 21 also covers the hatched flow duct 15 so that any damping fluid from the bottom through the flow duct 15 can only escape upwardly as the spring force of the shim valve is overcome.

[0061] The figure shows that in the flow duct 15 an adjusting unit 16 or a lance element 17 is disposed to be adjustable in the axial direction. The lance element 17 projects into the opening and provides only part of the feasible flow cross-section 14. As the adjusting unit 16 is retracted further out of the opening, the remaining flow cross-section increases, and vice versa. This is where the flow cross-section and the spring rate or spring rigidity of the spring device 11 can be influenced.

[0062] FIGS. 4 and 5 show the shim valve 20 which is biased to the closed position 12 by a spring device 11. The spring device 11 is composed of the shim unit 21 and the leaf which is presently designated a spring device 11. The spring device 11 comprises at least one roughly oval leaf acting as a positioning body 18 which is/are rotatably accommodated off-center on the central axle 22. Adjusting the angle of rotation of the positioning body 18 may be done from the outside.

[0063] In the position shown in a solid line the positioning body 18 resting on the shim unit 21 virtually covers the entire flow duct 15. This considerably increases the spring rate or spring rigidity of the spring device 11 in the region of the flow duct. The characteristic curve turns considerably steeper.

[0064] A position rotated 90 is shown in a dotted line. In this position, the positioning body 18 no longer rests on the shim unit 21 immediately above the flow duct 15. However, the spring constant of the spring device 11 is entirely changed in the region of the flow duct 15. The weakest spring constant of the spring device 11 is set with the spring device 11 positioned in the dash-dotted line. In this spot, the spring constant of the shim unit is influenced or boosted the least. The characteristic curve is adjusted correspondingly flatter.

[0065] The decisive flow cross-section is the gap beneath the shim unit 21 which is adjusted by an adjustable maximum deflecting amount of the shim unit 21.

[0066] FIG. 5 shows a sectional, schematic side view of the illustration according to FIG. 4, the spring device 11 also being in the position in which the positioning body 18 resting on the shim unit 21 extends entirely across the flow duct 15. This achieves particularly high rigidity of the spring constant of the system of the spring device 11 consisting of the positioning body 18 and the shim valve 20 so that a particularly large force must be applied to bend the shim unit 21 wide enough open. Moreover, the effective flow cross-section is variable by way of axially adjusting the adjusting unit 16. It is possible to provide only one of the two adjusting functions.

[0067] FIG. 6 shows a schematic illustration of an alternative throttle valve 13 which may e.g. be realized in the piston.

[0068] Again, the throttle valve 13 may comprise a shim valve and have a shim unit 21 which is shown in a dashed line since it is attached e.g. to the bottom end of the piston. The shim unit 21 may be a circular spring leaf and be centrally fixed to the axle 22.

[0069] The illustrated shim unit 21 covers all the flow ducts 15 so that any damping fluid can escape downwardly into the plane of the drawing through the flow ducts 15 only as the spring force of the shim valve is overcome.

[0070] The shim valve 20 is biased to the closed position 12 by a spring device 11 not shown in detail. In simple cases, the spring device 11 may be formed by the spring force of a spring leaf or of a stack of spring leaves.

[0071] The throttle valve 13 has disposed at what is the top end of the flow ducts 15 a rotatable positioning body 18 which covers a variable portion of the flow ducts 15 depending on the angle of rotation. The positioning body 18 is rotatably accommodated off-center on the central axle 22. An adjustment of the angle of rotation of the positioning body 18 is again possible from the exterior.

[0072] In the position shown in a solid line in FIG. 6, the positioning body 18 closes the majority of the flow ducts 15. Preferably, the positioning body 18 does not completely close all of the flow ducts 15 so that the shim packet can still open up and damping does not increase undesirably high or even infinitely high. Therefore, it is possible to have at least one flow duct 15 uncovered at all times (the flow duct 15 shown in a dashed line).

[0073] In the dashed-line rotary position of the positioning body 18, the positioning body 18 only closes part of the flow ducts 15, and in the dash-dotted line rotary position none of the flow ducts 15 is covered by the positioning body 18. This allows effectiveness of changing the flow resistance and the passage resistance of the high-speed throttle.

[0074] FIG. 7 shows the result of the adjustment options of the invention by way of two basically different characteristic damper curves. The characteristic damper curves having the break point 35 show a relatively steep low-speed range, while the characteristic damper curves having the break point 36 show just a slight rise in the low-speed range.

[0075] The two break points or transitions 35 and 36 are shown with two variants 31 and 32, and 33 and 34 each. It can clearly be seen that different settings for the high-speed range virtually show no effect on the low-speed range and also virtually no effect on the transition or break point 35 or 36. The flatter progression of the characteristic damper curve 31 is only flatter from the break point 35. No displacement takes place.

[0076] The same applies to the two characteristic damper curves 33 and 34, which also show the same paths up to the break point 36.

[0077] On the whole, the invention provides an advantageous adjustment option for the high-speed range without showing undesirable effects on the low-speed range. Adjustment is possible by way of changing the flow passage and/or the spring characteristics, and in particular the spring constant.

[0078] While particular embodiments of the present shock absorber for a bicycle have been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.

LIST OF REFERENCE NUMERALS

[0079]

TABLE-US-00001 1 damping system 2 damping chamber 3 first chamber 4 second chamber 5 piston 6 damper housing 7 equalizing chamber 8 dividing piston 10 high-speed throttle 11 spring device 12 closed position 13 throttle valve 14 flow cross-section 15 flow duct 16 adjusting unit 17 lance component 18 positioning body 19 flow valve 20 shim valve 21 shim unit 22 axle, axis 30 low-speed throttle 31 curve 32 curve 33 curve 34 curve 35 transition 36 transition 50 shock absorber 51 front wheel 52 rear wheel 53 frame 54 fork 55 rear wheel damper 56 handlebar 57 saddle 58 battery 59 spoke 60 tire 61 rim 100 bicycle