Damping device for a bicycle

Abstract

The invention relates to a damping device (28) for a bicycle (10), said damping device comprising an outer tube (30) and an inner tube (32) located coaxially to the outer tube, wherein a compensation chamber (34) for receiving hydraulic fluid is formed between the outer tube (30) and the inner tube (32), and also comprising a piston (40) which is connected to a piston rod (42) and can be moved back and forth within the inner tube (32), wherein the piston (40) divides the interior of the inner tube (32) into a working chamber (44) that is free of the piston rod and a working chamber (46) that contains the piston rod, wherein the damping device (28) also comprises a valve assembly (50) and an adjustment device (55) for adjusting the damping of the valve assembly (50) in the rebound stage and / or the compression stage, and wherein the damping device (28) has a gas reservoir (98) which is located coaxially to the adjustment device (55) and encircles the adjustment device (55).

Description

[0001] August 15, 2025

[0002] 1 / 29

[0003] Damping device for a bicycle

[0004] The invention relates to a damping device for a bicycle and a suspension fork of a bicycle with such a damping device.

[0005] Bicycles, especially mountain bikes, are often equipped with shock absorbers to dampen the bicycle's movement when riding over uneven terrain. Typically, the movement of each wheel, i.e., the rear wheel and the front wheel, is dampened by a separate shock absorber. For example, the rear wheel is connected to the bicycle frame via a rear shock absorber, and the front wheel via a suspension fork. The rear shock absorber and / or the suspension fork often incorporate a damping mechanism, such as a single-tube or multi-tube shock absorber.

[0006] A suspension fork with a damping device is known from DE102015115678A1.

[0007] Starting from this premise, the object of the present invention is to provide a damping device for a bicycle that is particularly low in wear and tear and can be manufactured cost-effectively.

[0008] This problem is solved according to the invention by a device having the features of independent device claim 1. Advantageous further developments are described in the dependent claims.

[0009] A damping device for a bicycle comprises, according to a first aspect, an outer tube and an inner tube arranged coaxially to it, wherein a compensation chamber for receiving hydraulic fluids is formed between the outer tube and the inner tube, and a piston connected to a piston rod, which is arranged to be movable back and forth within the inner tube, wherein the interior of the inner tube is divided by the piston into a working chamber remote from the piston rod and a working chamber on the side of the piston rod, and wherein the damping device includes a valve device and an adjusting device for adjusting the damping of the 15.08.2025

[0010] 2 / 29

[0011] The damping device has a valve assembly in the rebound and compression stages. It includes a gas reservoir arranged coaxially to and around the adjusting mechanism.

[0012] The gas storage unit primarily serves to compensate for volume changes during piston movement and offers a particularly simple design solution, eliminating the need for a dynamic seal between the gas chamber and the oil chamber.

[0013] The damping device preferably comprises an outer tube and an inner tube arranged coaxially to and within the outer tube, which is also referred to, for example, as a damper tube. The inner tube preferably has a smaller diameter than the outer tube and is arranged radially spaced from it, so that a compensating chamber filled with hydraulic fluid is formed between the inner and outer tubes. The outer and inner tubes are preferably attached at their lower ends to a base piece that seals the hydraulic fluid-filled inner and outer tubes, preferably forming a gas chamber of a spring fork, in a fluid-tight manner. For example, a valve is arranged in the base piece that fluidly connects the compensating chamber to the interior of the inner tube. In particular, the base piece does not have a valve.

[0014] A piston and a piston rod attached to it are arranged to be axially movable within the inner tube and coaxially to it. The piston preferably rests fluid-tight against the inner wall of the inner tube with its outer diameter and is slidably mounted along the inner wall of the inner tube in the axial direction, the inner tube preferably forming a guide for the piston. The piston rod extends, in particular, from the piston towards the base piece and centrally through it, the base piece having, for example, a central bore. Preferably, the piston rod is slidably mounted in the base piece in a fluid-tight manner in the axial direction. The piston preferably divides the interior of the inner tube into a first working chamber furthest from the piston rod and a second working chamber closer to the piston rod. The piston optionally includes a valve assembly. 15.08.2025

[0015] 3 / 29

[0016] At the upper end of the outer tube, the damping device preferably has a sealing assembly that is attached to the outer tube and seals the interior of the outer tube fluid-tight. The inner tube preferably does not extend as far as the sealing assembly. In particular, the inner tube extends to the valve assembly of the damping device.

[0017] The damping device preferably further comprises an adjustment device, which is designed and arranged such that the damping, in particular the damping characteristic, of the damping device can be adjusted in both the rebound and compression stages by means of the adjustment device. The adjustment device particularly includes a compression stage adjustment device for adjusting the damping in the compression stage and a rebound stage adjustment device for adjusting the damping in the rebound stage, wherein the compression stage adjustment device and the rebound stage adjustment device are preferably separate components.

[0018] According to a first embodiment, the gas accumulator rests against the outer tube. The gas accumulator is preferably a separate component and arranged separately from the outer tube and the adjustment mechanism. The gas accumulator is preferably designed such that its volume changes depending on the hydraulic pressure and / or the gas pressure. Preferably, a gap is formed between the gas accumulator and the outer tube, which is filled with hydraulic fluid. Preferably, the outer surface of the gas accumulator rests against the inner surface of the outer tube. The gas accumulator extends axially, preferably along approximately 50% to 90%, and in particular 80%, of the length of the adjustment mechanism.

[0019] According to a further embodiment, the gas storage unit rests against the adjusting device. Preferably, a gap filled with hydraulic fluid is formed between the gas storage unit and the adjusting device. In particular, the gas storage unit rests with its inner surface against the outer surface of the adjusting device. The adjusting device is preferably arranged coaxially with the outer tube.

[0020] According to another embodiment, the gas storage tank, particularly in its installed state, has a C-shaped cross-section. The gas storage tank is preferably 15.08.2025

[0021] 4 / 29 The gas reservoir is mat-shaped or cushion-shaped and, in the installed state, rolled up around the adjustment device. The gas reservoir is preferably designed as a gas bellows, gas pocket, or gas bladder. Preferably, the gas reservoir is partially annular, particularly partially circular, and has an outer surface facing the outer tube and an inner surface facing the adjustment device.

[0022] According to another embodiment, the gas accumulator is filled with a compressible gas, in particular nitrogen. Unlike the hydraulic fluid, the gas in the accumulator is compressible and therefore able to compensate for changes in volume when the pressure of the hydraulic fluid increases or decreases.

[0023] According to another embodiment, the gas storage unit has exactly one gas chamber. This allows for particularly simple and cost-effective manufacturing of the gas storage unit. Optionally, the gas storage unit has multiple gas chambers, for example, 2 to 10 gas chambers. The gas chamber is preferably filled exclusively with the compressible gas.

[0024] According to a further embodiment, the gas storage tank has flexible walls, preferably made of aluminum and / or a composite foil. The gas storage tank preferably comprises exactly one, two, or more flexible side walls, which are bonded together, in particular welded. The gas chamber, which is fluid-tight, is formed between the side walls. Preferably, the gas storage tank comprises exactly one gas-filled gas chamber. In a rolled-up state, the side walls of the gas storage tank are, for example, square, in particular rectangular, and are joined by a weld seam running around the outer edge. By way of example, the gas storage tank has exactly two side walls. In the installed state, the gas storage tank is rolled up around its central axis into a C-shape, so that a radially outer side wall and a radially inner side wall are formed.In its rolled-up state, the inner side wall exhibits, in particular, a plurality of, for example, axially extending creases, which are, in particular, evenly spaced from one another. The outer side wall is located on August 15, 2025.

[0025] 5 / 29

[0026] The side wall is attached to the outer tube, and the inner side wall rests, for example, against the adjustment device.

[0027] According to a further embodiment, the valve assembly comprises a compression stage valve for damping the piston movement in the compression stage and a rebound stage valve for damping the piston movement in the rebound stage. The adjusting device includes a compression stage adjusting device for setting the damping of the compression stage valve and a rebound stage adjusting device for setting the damping of the rebound stage valve. The compression stage adjusting device and the rebound stage adjusting device are preferably designed as separate components. The compression stage valve is preferably arranged and configured such that it dampens the movement of the piston in the compression stage when the piston moves towards the sealing element. The rebound stage valve is preferably arranged and configured such that it dampens the movement of the piston in the rebound stage when the piston moves towards the base.The pressure stage valve is arranged by way of example inside the inner tube, in particular at the upper end of the inner tube.

[0028] The pressure stage valve preferably comprises a pressure stage valve body, which is preferably located entirely within the inner tube and is rigidly connected to it. For example, the pressure stage valve body is connected to the inner tube via a positive-locking, force-locking, or material-locking connection. Preferably, the pressure stage valve body rests fluid-tight against the inner wall of the inner tube. The pressure stage valve body has, in particular, at least one or a plurality of axially extending through-bores. The pressure stage valve preferably comprises a pressure stage spring washer assembly, which rests against the pressure stage valve body in such a way that it covers the through-bore and, in particular, seals it fluid-tight.The pressure stage valve includes, for example, a fastening element, in particular a bolt or screw, which extends axially through the pressure stage valve body and to which the pressure stage spring washer assembly is optionally attached. The pressure stage spring washer assembly preferably comprises at least one or a plurality of spring washers. The pressure stage spring washer assembly is located, for example, on the upwardly facing end face of the valve body.

[0029] 6 / 29

[0030] The pressure stage valve body preferably comprises a flow passage that extends separately, particularly parallel to the flow passage, and is fluid-tightly covered by a check valve disc at the lower end of the pressure stage valve body. Preferably, the flow passage is open to hydraulic fluid flow exclusively in the compression direction and the flow passage exclusively in the compression direction.

[0031] The pressure stage valve comprises, in particular, a pressure stage spring which rests against the pressure stage spring washer assembly and applies a preload force to it in the closing direction of the pressure stage valve. The pressure stage valve preferably includes the pressure stage adjustment device for adjusting the damping, in particular the damping characteristic, of the pressure stage valve in the pressure stage, and especially for adjusting the preload of the pressure stage spring washer assembly.

[0032] The rebound valve preferably has a rebound valve body that is attached to the upper end region, in particular the upper end face, of the inner tube. The rebound valve body is preferably located entirely within the outer tube and rigidly connected to it. For example, the rebound valve body is rigidly connected to the outer tube. In particular, the outer tube has a shoulder, in particular a diameter constriction, on its inner wall against which the rebound valve body rests. Preferably, the rebound valve body is in a fluid-tight seal against the inner wall of the outer tube. The rebound valve body has at least one or a plurality of flow passages extending in the axial direction. The rebound valve preferably includes a rebound spring washer assembly that rests against the rebound valve body in such a way that it covers the flow passages and, in particular, seals them fluid-tight.The rebound damping spring washer assembly is, in particular, mounted in an axial recess on the axially upward-facing end face of the rebound damping valve body. The rebound damping spring washer assembly preferably comprises at least one or a plurality of spring washers. The rebound damping valve body preferably comprises a flow channel that extends separately, in particular parallel to the flow passage in the rebound damping valve body, and is terminated by a check valve washer at the lower end of the valve body.

[0033] 7 / 29

[0034] The rebound valve body is covered in a fluid-tight manner. Preferably, the flow passage is exclusively open to hydraulic fluid during the rebound stage, and the flow channel is exclusively open to hydraulic fluid during the compression stage. The flow channel is, for example, arranged radially outwards from the flow passage in the rebound valve body. The rebound valve preferably comprises a preload spring that bears against the check valve disc and applies a preload force to it. The preload spring preferably bears against the check valve disc at one end and against the inner tube, in particular the upper end face of the inner tube, at the other end. The preload spring is preferably a coil spring.

[0035] The rebound damping valve preferably comprises a rebound damping spring that rests against the rebound damping spring assembly and applies a preload force to it in the closing direction of the rebound damping valve. The rebound damping spring is preferably a coil spring. The rebound damping valve preferably includes the rebound damping adjustment device for adjusting the damping, in particular the damping characteristic of the rebound damping valve during rebound, and especially for adjusting the preload of the rebound damping spring assembly.

[0036] According to a further embodiment, the rebound damping adjustment device has a hollow cylindrical rebound damping adjustment rod, and the compression damping adjustment device has a compression damping adjustment rod that is at least partially arranged inside the rebound damping adjustment rod. The compression damping adjustment device, in particular, has a compression damping adjustment rod arranged coaxially to the outer tube, which preferably extends from the locking assembly into the inner tube. The rebound damping adjustment device has a rebound damping adjustment rod arranged coaxially to the outer tube, which preferably extends axially downwards from the locking assembly.

[0037] The pressure stage adjusting rod is preferably mounted within the outer tube so as to be movable in the axial direction. Preferably, the pressure stage adjusting rod is mounted so as to be movable relative to the outer tube, the inner tube, and the pressure stage valve body. The pressure stage adjusting device is particularly designed and configured as follows: 15.08.2025

[0038] 8 / 29 that a downward axial movement of the compression adjustment rod increases the preload of the compression spring washer assembly and an upward axial movement of the compression adjustment rod decreases the preload of the compression spring washer assembly.

[0039] The rebound damping adjustment rod is preferably mounted within the outer tube so as to be axially movable. Preferably, the rebound damping adjustment rod is mounted so as to be movable relative to the outer tube, the inner tube, and the rebound damping valve body. The rebound damping adjustment device is designed and configured such that a downward axial movement of the rebound damping adjustment rod increases the preload of the rebound damping spring washer assembly, and an upward axial movement of the rebound damping adjustment rod decreases the preload of the rebound damping spring washer assembly.

[0040] The rebound damping adjustment rod and the compression damping adjustment rod are preferably arranged coaxially. For example, the rebound damping adjustment rod is tubular and has a larger diameter than the compression damping adjustment rod. The compression damping adjustment rod preferably extends at least partially inside the rebound damping adjustment rod. For example, the inner surface of the rebound damping adjustment rod rests against the outer surface of the compression damping adjustment rod, particularly in a fluid-tight manner. The compression damping adjustment rod preferably extends axially downwards beyond the rebound damping adjustment rod, particularly into the inner tube.

[0041] The compression spring preferably rests at one end against the compression spring washer assembly and at the other end against the compression adjusting rod. Preferably, the compression adjusting rod has a contact area designed for the compression spring and is located at its lower end. This contact area preferably has a larger diameter than the axially extending section of the compression adjusting rod. The contact area of ​​the compression adjusting rod is preferably spaced apart from the inner tube, so that a gap exists between the inner tube and the compression adjusting rod, particularly the contact area.

[0042] 9 / 29

[0043] The inner tube is formed as an annular channel. The pressure-stage adjusting rod is, for example, formed in one piece or as a single unit. The pressure-stage adjusting rod has, for instance, a separate contact area that is firmly attached to a section of the rod. The upper end of the inner tube has, in particular, a decreasing diameter with a central opening through which the pressure-stage adjusting rod extends.

[0044] The rebound spring preferably rests at one end against the rebound spring washer assembly and at the other end against the rebound adjusting rod. Preferably, the rebound adjusting rod has a receiving area designed to accommodate the rebound spring. This receiving area is preferably located at the lower end of the rebound adjusting rod and has a larger diameter than the section of the rebound adjusting rod that extends upwards in the axial direction. The receiving area of ​​the rebound adjusting rod is preferably arranged axially spaced from the rebound valve body.

[0045] During operation, the damping device operates in both the rebound and compression stages. In the compression stage, the hydraulic fluid flows from the working chamber furthest from the piston rod through the compression stage valve and then through the flow channel into the compensation chamber. In the rebound stage, the hydraulic fluid flows from the compensation chamber into the rebound stage valve and then through the annular channel and the flow passage into the working chamber furthest from the piston rod.

[0046] According to another embodiment, the gas reservoir rests against the rebound adjustment rod. For example, the gas reservoir is arranged above the receiving area of ​​the rebound adjustment rod and, in particular, is spaced apart from this receiving area. The gas reservoir is preferably arranged completely separately from the adjustment mechanism and the outer tube.

[0047] According to another embodiment, the gas storage tank has a valve for filling it. This valve is, for example, a check valve. The valve is preferably located at the upward-facing end of the gas storage tank, particularly the end facing the sealing assembly. 15.08.2025

[0048] 10 / 29

[0049] According to another embodiment, the valve is mounted within the sealing assembly. Preferably, the valve is arranged completely or partially within the sealing assembly. The sealing assembly preferably has a filling channel extending from a valve inlet out of the sealing assembly and opening into a filling port. The valve is, for example, mounted in the sealing assembly by means of a positive-locking and / or force-locking connection. The sealing assembly has, in particular, an axial bore in its downward-facing surface in which the valve is mounted. The gas storage device is preferably mounted in the damping device exclusively by means of the valve mounted within the sealing assembly. This allows the gas storage device to be positioned within the damping device in a simple and secure manner.

[0050] According to a further embodiment, the walls of the gas storage tank are connected to one another by means of a weld, and a connecting block to which the valve is attached is arranged within the weld. The gas storage tank preferably has a weld that seals the gas chamber completely or partially in a fluid-tight manner. The weld, for example, extends completely around the gas chamber and is, in particular, rectangular in shape when coiled. A connecting block is attached to the upward-facing end of the gas storage tank in the installed state, particularly within the weld. The connecting block preferably extends axially completely through the weld into the gas chamber. Preferably, the valve is attached to the connecting block or formed integrally with it. The connecting block preferably has a round, oval, circular, or elliptical cross-section.In particular, the connecting block is fluid-tight within the weld seam, especially between the outer and inner side walls. The connecting block preferably includes a bore, particularly an axial bore, which is fluidically connected to the valve and, in particular, to the filling channel. The bore has, for example, a round, circular, oval, or elliptical cross-section.

[0051] The invention optionally also includes a suspension fork for a bicycle with at least one damping device as described above. This application was filed on August 15, 2025.

[0052] The terms "top", "bottom", "front", and "rear" used in section 11 / 29 refer to the usual operating position of a bicycle with a suspension device. The suspension fork is preferably connected to the bicycle frame and front wheel and preferably incorporates the suspension device so that the movement of the front wheel is dampened by the suspension fork. Optionally, the bicycle has a rear shock absorber, which is preferably connected to the bicycle frame and rear wheel and may also incorporate a suspension device, so that the movement of the rear wheel is dampened by the rear shock absorber.

[0053] According to a further embodiment, the spring fork has two legs, each having a slider tube and a stanchion tube, wherein the stanchion tube is at least partially slidably arranged within the respective slider tube, and wherein a damping device is attached in one or both legs, and wherein the respective piston rod is attached to the respective slider tube.

[0054] The suspension fork comprises, for example, a first leg and a second leg, and a fork crown to which the two legs are attached. The first and second legs are preferably each attached to the fork crown at their upper ends and extend parallel to each other. The legs are preferably each designed as a telescopic tube and, for example, each have a stanchion and a slider tube. The slider tube is, in particular, rigidly connected to the fork crown. Preferably, the slider tube of each leg has a smaller diameter than the stanchion tube of the respective leg. The slider tube is preferably arranged, at least partially, and especially with its lower end, within the respective slider tube. Preferably, the slider tube is arranged to be telescopically and slidably mounted within the respective slider tube.The fork tubes are preferably connected to each other and to the front wheel via an axle, particularly at their lower ends.

[0055] The damping device is arranged, in particular, within a leg designed as a telescopic tube. Optionally, the suspension fork has two damping devices, with one damping device arranged in each leg. Preferably, a [15.08.2025] is located within the first and second legs.

[0056] 12 / 29

[0057] A gas space is formed, with the interior of the dip tube and the interior of the standpipe being filled with a gas.

[0058] The outer tube of the damping device is arranged coaxially to the stanchion and the slider tube and has a smaller diameter than these. The outer tube is preferably arranged radially spaced from the stanchion and the slider tube, with a gas-filled annular space formed between the outer tube and the stanchion and the slider tube. The piston rod extends axially, preferably to the lower end of the slider tube, and is attached to it, so that the slider tube and the piston rod are preferably not movable relative to each other. The sealing assembly is preferably fixedly connected to the stanchion tube and seals the interior of the stanchion tube, preferably in a fluid-tight, and in particular gas-tight, manner. The sealing assembly is preferably attached to the fork crown.

[0059] The invention optionally also includes a bicycle comprising a previously described suspension fork and / or a rear shock absorber with a previously described damping device.

[0060] Description of the drawings

[0061] The invention is explained in more detail below with reference to several exemplary embodiments and the accompanying figures.

[0062] Fig. 1 shows a schematic representation of a bicycle with a suspension fork and a rear shock absorber in a side view according to an exemplary embodiment.

[0063] Fig. 2 shows a schematic representation of a spring fork in a sectional view according to a further embodiment.

[0064] Fig. 3 shows a schematic representation of a section of a leg of a suspension fork with a damping device in a longitudinal sectional view according to an exemplary embodiment. 15.08.2025 13 / 29

[0065] Fig. 4 shows a schematic representation of a valve assembly of the damping device in a longitudinal sectional view according to an exemplary embodiment.

[0066] Fig. 5 shows a schematic representation of a section of a damping device with a gas storage tank in a longitudinal sectional view according to an exemplary embodiment.

[0067] Fig. 6 shows a schematic representation of a section of a damping device with a gas storage unit in a semi-perspective longitudinal section view according to an exemplary embodiment.

[0068] Fig. 7 shows a schematic representation of a gas storage tank in a perspective view according to an exemplary embodiment.

[0069] Fig. 1 shows a schematic representation of a bicycle 10 with a suspension fork 12 and a rear shock absorber 14. Fig. 1 shows a bicycle 10 in an operating position, where the terms used below, such as "top", "bottom", "front", and "rear", refer to the operating position of the bicycle 10 shown. The suspension fork 12 is preferably connected to the bicycle frame and front wheel of the bicycle 10 and preferably has a damping device 28 so that the movement of the front wheel is dampened by means of the suspension fork 12. The rear shock absorber 14 is preferably connected to the bicycle frame and the rear wheel and also has, for example, a damping device 28 so that the movement of the rear wheel is dampened by means of the rear shock absorber 14.

[0070] Fig. 2 shows a suspension fork 12. The suspension fork 12 comprises a first leg 16 and a second leg 18. The suspension fork 12 further comprises a fork crown 20 to which the two legs 16, 18 are attached. The first and the second legs 16, 18 are each attached to the fork crown 20 at their upper ends and extend parallel to each other. A head tube 22 is preferably attached to the fork crown 20 for attaching the suspension fork 12 within the bicycle frame, in particular to a handlebar. The legs 16, 18 are 15.08.2025

[0071] 14 / 29 preferably each designed as a telescopic tube and each having, for example, a slider tube 24a, b and a stanchion tube 26a, b. The stanchion tube 26a, b is in particular rigidly connected to the fork crown 20 or formed integrally with it. Preferably, the stanchion tube 26a, b of each leg 16, 18 has a smaller diameter than the slider tube 24a, b of the respective leg 16, 18. The stanchion tube 26a, b is preferably arranged at least partially, in particular with its lower end region, within the respective slider tube 24a, b. Preferably, the stanchion tube 26a, b is arranged to slide within the respective slider tube 24a, b, preferably telescopically. The slider tubes 24a, b are in particular connected at their lower ends preferably to each other and to the front wheel via an axis (not shown). For example, the slider tubes 24a, b are additionally connected at their upper end via a bracket.

[0072] The spring fork 12 further preferably comprises at least one damping device 28. The damping device 28 is arranged, in particular, within the leg 16, 18, which is designed as a telescopic tube. By way of example, only one damping device 28 is arranged in the first leg 16 of the spring fork 12 in Fig. 2. For example, the spring fork 12 has two damping devices 28, with one damping device 28 arranged in each leg 16, 18. The following description refers, by way of example, to the damping device 28 arranged in the first leg 16. Optionally, a further damping device 28, preferably of identical design, is arranged within the second leg 18. A gas chamber 38 is preferably formed within the first and the second legs 16, 18, wherein the interior of the stanchion tube 24 and the interior of the upright tube 26 are filled with a gas.Preferably, a damping device 28 is arranged exclusively in one leg, 16, 18, for example in the leg 16 on the right in the direction of travel. In the second leg 18, for example a gas spring (not shown), in particular an air spring, and / or a steel spring is arranged.

[0073] The damping device 28 is shown enlarged in Fig. 3 and includes, by way of example, an outer tube 30, which is arranged coaxially to the standpipe 26 and the immersion tube 24 and has a smaller diameter than these. The outer tube 30 15.08.2025

[0074] The outer tube 30 is preferably arranged radially spaced from the standpipe 26 and the immersion tube 24, with a gas-filled annular space being formed between the outer tube 30 and the standpipe 26 and the immersion tube 24. An inner tube 32, which may also be referred to as a damper tube 32, is arranged coaxially to and within the outer tube 30. The inner tube 32 has a smaller diameter than the outer tube 30 and is arranged radially spaced from it, so that a compensating chamber 34 filled with hydraulic fluid is formed between the inner tube 32 and the outer tube 30. The outer tube 30 and the inner tube 32 are preferably attached at their lower ends to a base piece 36, which seals the hydraulic fluid-filled inner tube 32 and outer tube 30 against the gas space 38 in a fluid-tight manner.For example, a valve is arranged in the base piece 36, which fluidically connects the compensation chamber 34 to the interior of the inner tube 32. In particular, the base piece 36 does not have a valve.

[0075] A piston 40 and a piston rod 42 attached to it are arranged to be axially movable within and coaxial to the inner tube 32. The piston 40 preferably rests fluid-tight against the inner wall of the inner tube 32 with its outer diameter and is slidably mounted along the inner wall of the inner tube 32 in the axial direction, the inner tube 32 preferably forming a guide for the piston 40. The piston rod 42 extends from the piston 40 towards the base piece 36 and centrally through it, the base piece 36 having a central bore. Preferably, the piston rod 42 is slidable through the base piece 36 in a fluid-tight manner in the axial direction. The piston rod 42 preferably extends axially to the lower end of the immersion tube 24 and is attached to it, so that the immersion tube 24 and the piston rod 42 are preferably not movable relative to each other.

[0076] The piston 40 preferably divides the interior of the inner tube 32 into a first working chamber 44, located away from the piston rod, and a second working chamber 46, located closer to the piston rod, by means of a fluid flow system. The piston 40 preferably includes a valve assembly (not shown). 15.08.2025

[0077] 16 / 29

[0078] At the upper end of the outer tube 30, the damping device 28 has a sealing assembly 48, which is attached to the outer tube 30 and seals the interior of the outer tube 30 fluid-tight. The sealing assembly 48 is preferably rigidly connected to the stanchion 26 and seals the interior of the stanchion 26 preferably fluid-tight, and in particular gas-tight. The sealing assembly 48 is preferably attached to the fork crown 20. The inner tube 32 preferably does not extend to the sealing assembly 48. In particular, the inner tube 32 extends to a valve assembly 50 of the damping device 28.

[0079] The valve assembly 50 preferably comprises a first valve 52, also referred to as the compression stage valve 52, and a second valve 54, also referred to as the rebound stage valve 54. The compression stage valve 52 is preferably arranged and configured such that it dampens the movement of the piston 40 in the compression stage when the piston moves upwards in the compression direction D, particularly towards the closure assembly 48. The rebound stage valve 54 is preferably arranged and configured such that it dampens the movement of the piston 40 in the rebound stage when the piston moves downwards in the tension direction Z, particularly towards the base piece 36. The compression stage valve 52 is preferably arranged inside the inner tube 32, particularly at the upper end of the inner tube 32. The damping device 28 further preferably comprises an adjusting device 55 for adjusting the damping in the rebound and compression stages.The adjusting device 55 includes in particular a compression stage adjusting device 68 as described with reference to Fig. 4 and a rebound stage adjusting device 92.

[0080] Fig. 4 shows a detailed view of the valve assembly 50. The pressure stage valve 52 includes, by way of example, a pressure stage valve body 56, which is preferably mounted completely inside the inner tube 32 and is firmly connected to it. For example, the pressure stage valve body 56 is connected to the inner tube via a positive-locking, force-locking, or material-locking connection. By way of example, the inner tube 32 has a recess on its inner wall, and the pressure stage valve body 56 has a projection on its outer surface that is arranged in the recess and interacts with it to form a positive-locking connection. Preferably, the pressure stage valve body 56 is fluid-tight against the inner tube 32.

[0081] 17 / 29

[0082] The inner wall of the inner tube 32. The pressure stage valve body 56 has at least one or a plurality of axially extending through-bores 58. The pressure stage valve 52 preferably comprises a pressure stage spring washer assembly 60, which rests against the pressure stage valve body 56 in such a way that it covers the through-bore 58 and, in particular, seals it fluid-tight. The pressure stage valve 52 optionally includes a fastening element 74, in particular a bolt or screw, which extends axially through the pressure stage valve body 56 and to which, optionally, the pressure stage spring washer assembly 60 is attached. The pressure stage spring washer assembly 60 preferably comprises at least one or a plurality of spring washers. The pressure stage spring washer assembly 60 optionally rests against the upwardly facing end face of the pressure stage valve body 56.The pressure stage valve body 56 preferably comprises a flow passage 62, which extends separately, in particular parallel to the passage bore 58, and is fluid-tightly covered by a check valve disc 64 at the lower end of the pressure stage valve body 56. Preferably, the passage bore 58 is open to hydraulic fluid exclusively in the pressure direction D and the flow passage 62 exclusively in the tension direction Z.

[0083] The pressure stage valve 52 includes, for example, a pressure stage spring 66, which bears against the pressure stage spring washer assembly 60 and applies a preload force to it in the closing direction of the pressure stage valve 52. The pressure stage spring 66 is preferably a coil spring. The pressure stage valve 52 preferably includes a pressure stage adjusting device 68 for adjusting the damping in the pressure stage, in particular the preload of the pressure stage spring washer assembly 60. The pressure stage adjusting device 68 has a pressure stage adjusting rod 70 arranged coaxially to the outer tube 30, which preferably extends from the closure assembly 48 into the inner tube 32.

[0084] The compression spring 66 preferably rests at one end against the compression spring washer assembly 60 and at the other end against the compression adjusting rod 70. Preferably, the compression adjusting rod 70 has a contact area 72 designed to bear against the compression spring 66. The contact area 72 is preferably located at the lower end of the compression adjusting rod 70 and preferably has a larger diameter than the axially extending upwards section of the compression adjusting rod 70. By way of example, the contact area 72 is hollow cylindrical. The contact area 72 includes, by way of example, an annular surface facing downwards, preferably towards the compression spring washer assembly 60, against which the compression spring 66 bears.Furthermore, the contact area 72 preferably has a hollow cylinder section, which is designed, for example, as a guide for the compression spring 66, and wherein the compression spring 66 optionally bears against the outer surface of the hollow cylinder section. The fastening element 74 is, by way of example, at least partially arranged inside the hollow cylinder section. The contact area 72 of the compression adjusting rod 70 is preferably arranged at a distance from the inner tube 32, such that an annular channel 76 is formed between the inner tube 32 and the compression adjusting rod 70, in particular the contact area 72. The compression adjusting rod 70 is, for example, formed in one piece or as a single component. By way of example, the compression adjusting rod 70 of Fig. 4 has a separate contact area that is fixedly attached to a rod section of the compression adjusting rod 70.The upper end region of the inner tube 32 has a decreasing diameter with a central opening through which the pressure stage adjusting rod 70 extends.

[0085] The compression adjustment rod 70 is preferably mounted within the outer tube 30 so as to be movable in the axial direction. Preferably, the compression adjustment rod 70 is mounted so as to be movable relative to the outer tube 30, the inner tube 32, and the compression valve body 56. The compression adjustment device 68 is designed and configured such that a downward axial movement of the compression adjustment rod 70 increases the preload of the compression spring washer assembly 60, and an upward axial movement of the compression adjustment rod 70 decreases the preload of the compression spring washer assembly 60.

[0086] The rebound valve 54 has, by way of example, a rebound valve body 78 which is attached to the upper end region, in particular the upper end face of the inner tube 32. The rebound valve body 78, which is preferably completely within the outer tube 15.08.2025

[0087] 19 / 29

[0088] The rebound valve body 78 is attached to and firmly connected to the outer tube 30. For example, the rebound valve body 78 is connected to the outer tube 30 via a positive-locking, force-locking, or material-locking connection. The outer tube 30 may, for example, have a shoulder, in particular a diameter constriction, on its inner wall against which the rebound valve body 78 rests. The shoulder may, for example, have an end face extending downwards in an axial direction against which the rebound valve body 78 preferably rests in a fluid-tight manner. Preferably, the rebound valve body 78 rests fluid-tight against the inner wall of the outer tube 30. The rebound valve body 78 has at least one or a plurality of flow passages 80 extending in the axial direction. The rebound valve 54 preferably comprises a rebound spring washer assembly 82, which rests against the rebound valve body 78 in such a way that it covers the flow passages 80 and, in particular, seals them fluid-tight.The rebound damping spring washer assembly 82 is, by way of example, mounted in an axial recess on the axially upward-facing end face of the rebound damping valve body 78. The rebound damping spring washer assembly 82 preferably comprises at least one or a plurality of spring washers. The rebound damping valve body 78 preferably comprises a flow channel 84, which extends separately, in particular parallel to the flow passage 80 in the rebound damping valve body 78, and is fluid-tightly covered by a check valve washer 86 at the lower end of the rebound damping valve body 78. Preferably, the flow passage 80 is accessible to hydraulic fluid exclusively in the rebound stage and the flow channel 84 exclusively in the compression stage. The flow channel 84 is, by way of example, arranged radially outward from the flow passage 80 in the rebound damping valve body 78.The rebound valve 54 further comprises, by way of example, a preload spring 88 which bears against the check valve disc 86 and applies a preload force to it. The preload spring 88 preferably bears against the check valve disc 86 at one end and against the inner tube 32, in particular the upper end face of the inner tube 32, at the other end. The preload spring 88 is, by way of example, a coil spring which is arranged coaxially with the compression adjustment rod 70.

[0089] The rebound valve 54 includes, for example, a rebound spring 90 which rests against the rebound spring washer assembly 82 and applies a preload force to it on 15.08.2025

[0090] 20 / 29

[0091] The closing direction of the rebound damping valve 54 is actuated. The rebound damping spring 90 is preferably a coil spring. The rebound damping valve 54 preferably comprises a rebound damping adjustment device 92 for adjusting the damping in the rebound stage, in particular the preload of the rebound damping spring washer assembly 82. The rebound damping adjustment device 92 has a rebound damping adjustment rod 94 arranged coaxially to the outer tube 30, which preferably extends downwards in an axial direction from the closure assembly 48.

[0092] The rebound spring 90 preferably rests at one end against the rebound spring washer assembly 82 and at the other end against the rebound adjusting rod 94. Preferably, the rebound adjusting rod 94 has a receiving area 96 designed to accommodate the rebound spring 90. The receiving area 96 is preferably located at the lower end of the rebound adjusting rod 94 and has a larger diameter than the axially upward-extending portion of the rebound adjusting rod 94. The receiving area 96 includes, for example, an annular recess with a downward-facing surface, preferably facing the rebound spring washer assembly 82, against which the rebound spring 90 rests. The rebound spring 90 preferably rests with its inner surface against the receiving area 96. The receiving area 96 of the rebound adjusting rod 94 is preferably arranged axially spaced from the rebound valve body 78.The rebound adjustment rod 94 is, for example, formed in one piece or as a single unit. By way of example, the rebound adjustment rod 94 has a separate receiving area 96 which is fixedly attached to a section of the rebound adjustment rod 94.

[0093] The rebound damping adjustment rod 94 is preferably mounted so as to be axially movable within the outer tube 30. Preferably, the rebound damping adjustment rod 94 is mounted so as to be movable relative to the outer tube 30, the inner tube 32, and the rebound damping valve body 78. The rebound damping adjustment device 92 is designed and configured such that a downward axial movement of the rebound damping adjustment rod 94 increases the preload of the rebound damping spring washer assembly 82, and an upward axial movement of the rebound damping adjustment rod 94 decreases the preload of the rebound damping spring washer assembly 82. 15.08.2025

[0094] 21 / 29

[0095] The rebound adjustment rod 94 and the compression adjustment rod 70 are preferably arranged coaxially. For example, the rebound adjustment rod 94 is tubular and has a larger diameter than the compression adjustment rod 70. The compression adjustment rod 70 preferably extends at least partially inside the rebound adjustment rod 94. For example, the inner surface of the rebound adjustment rod 94 rests against the outer surface of the compression adjustment rod 70, particularly in a fluid-tight manner. The compression adjustment rod 70 preferably extends axially downwards beyond the rebound adjustment rod 94, particularly into the inner tube 32.

[0096] In operation of the suspension fork 12, the damping device 28 is operated in both the rebound and compression stages. In the compression stage, the hydraulic fluid flows from the working chamber 44 furthest from the piston rod through the compression stage valve 52 and then through the flow channel 84 into the compensation chamber 34. In the rebound stage, the hydraulic fluid flows from the compensation chamber 34 into the rebound stage valve 54 and then through the annular channel 76 and the flow passage 62 into the working chamber 44 furthest from the piston rod. The hydraulic fluid flow in the rebound stage is represented by the dotted arrow line, and the hydraulic fluid flow in the compression stage is represented by the dashed arrow line.

[0097] The damping device 28 also includes, in particular, a gas reservoir 98, which is installed inside the outer tube 30. The gas reservoir 98 is preferably filled with nitrogen or another compressible gas such as air. By way of example, the gas reservoir 98 is arranged around the adjusting device 55. Preferably, the gas reservoir 98 is partially annular, in particular partially circular, and has an outer surface facing the outer tube 30 and an inner surface facing the adjusting device 55. Preferably, the outer surface of the gas reservoir 98 rests against the inner surface of the outer tube 30. By way of example, the inner surface of the gas reservoir 98 rests against the outer surface of the adjusting device 55, in particular the rebound adjustment rod 94. The gas reservoir 98 extends axially, preferably along approximately 50% to 90%, in particular 80%, of the length of the adjusting device 55.For example, the gas storage tank 98 is arranged above the receiving area 96 of the rebound adjustment rod 94 and in particular on 15.08.2025.

[0098] The gas storage unit 98 is arranged at a distance from the receiving area 96 (22 / 29). It is preferably arranged completely separately from the adjusting device 55 and the outer tube 30.

[0099] The gas storage device 98, as shown for example in Fig. 5, preferably has exactly one gas chamber or a plurality of gas chambers. The gas storage device 98 is preferably designed as a gas bellows, gas pocket, or gas bladder. Preferably, the gas storage device 98 has flexible walls and is in particular made of a composite film, for example, of aluminum foil.

[0100] Fig. 6 shows the gas storage tank 98 in a partial perspective view within the damping device 28. The gas storage tank 98 includes, by way of example, a valve 100 for filling the gas storage tank 98 with gas. The valve 100 is preferably arranged at the end of the gas storage tank 98 that points upwards, particularly towards the sealing assembly 48. By way of example, the valve 100 is arranged completely or partially within the sealing assembly 48. The sealing assembly 48 preferably has a filling channel 102 that extends from a valve inlet out of the sealing assembly 48 and opens into a filling opening. The valve 100 is, by way of example, secured in the sealing assembly 48 by means of a positive-locking and / or force-locking connection. Preferably, the valve 100 is secured in the sealing assembly 48 by means of a snap-fit ​​connection.The sealing assembly 48 has, for example, an axial bore 104 in its downward-facing surface, in which the valve 100 is arranged. The gas storage tank 98 is preferably mounted in the damping device 28 exclusively by means of the valve 100, which is fastened within the sealing assembly 48.

[0101] Fig. 7 shows a gas storage tank 98 in a perspective view. The gas storage tank 98 comprises, by way of example, two flexible side walls which are joined together by a material bond, in particular by welding. A gas chamber is formed between the side walls, which is sealed in a fluid-tight manner. Preferably, the gas storage tank 98 comprises exactly one gas-filled gas chamber. The gas storage tank 98 preferably has a weld 106 which seals the gas chamber completely or partially in a fluid-tight manner. The weld 106 extends, by way of example, completely around the gas chamber. 15.08.2025

[0102] 23 / 29 and is, in particular, rectangular in its rolled-up state. The gas storage tank 98, by way of example, has a C-shaped cross-section in its rolled-up installed state. The side walls of the gas storage tank 98, in its rolled-up state, are, for example, rectangular, and are connected to each other by the weld seam 106 circumferentially around the outer edge. By way of example, the gas storage tank 98 has exactly two side walls 108, 110. In its installed state, the gas storage tank is rolled up around its central axis into a C-shape, so that a radially outer side wall 108 and a radially inner side wall 110 are formed. The inner side wall 110, in its rolled-up state, has a plurality of, for example, axially extending creases, which are, in particular, evenly spaced from each other.In particular, the outer side wall rests against the outer tube 30 and the inner side wall 110 rests, for example, against the rebound adjustment rod 94.

[0103] A connecting block 114 is attached to the upward-facing end of the gas storage unit 98 in its installed state, particularly within the weld seam 106. The connecting block 114 preferably extends axially completely through the weld seam 106 into the gas chamber. Preferably, the valve 100 is attached to the connecting block 114 or formed integrally with it. The connecting block 114 preferably has a round, oval, circular, or elliptical cross-section. In particular, the connecting block is fluid-tight within the weld seam 106, especially between the outer side wall 108 and the inner side wall 110. The connecting block 114 preferably includes a bore 116, particularly an axial bore, which is fluidically connected to the valve 100 and, in particular, to the filling channel 102. 15.08.2025

[0104] 24 / 29

[0105] Reference symbol list

[0106] 10 bicycles

[0107] 12 Suspension fork

[0108] 14 rear wheel dampers

[0109] 16 first leg of the suspension fork

[0110] 18 second leg of the suspension fork

[0111] 20 Fork crown

[0112] 22 Head tube

[0113] 24a, b immersion tube

[0114] 26a, b Standpipe

[0115] 28 Damping device

[0116] 30 Outer pipe

[0117] 32 Inner tube / Damper tube

[0118] 34 Compensation area

[0119] 36 bottom piece

[0120] 38 Gas space

[0121] 40 pistons

[0122] 42 Piston rod

[0123] 44 working space far from piston rod

[0124] 46 piston rod side working space

[0125] 48 sealing packs

[0126] 50 Valve assembly

[0127] 52 first valve / pressure stage valve

[0128] 54 second valve / rebound valve

[0129] 55 Adjustment device

[0130] 56 pressure stage valve bodies

[0131] 58 through hole

[0132] 60 compression spring disc package

[0133] 62 Flow passage

[0134] 64 Check valve disc

[0135] 66 compression spring

[0136] 68 pressure stage adjustment device

[0137] 70 pressure-level adjustment rod

[0138] 72 Investment area

[0139] 74 Fasteners

[0140] 76 Ring channel

[0141] 78 Rebound valve bodies

[0142] 80 Flow passage

[0143] 82 Rebound damping spring disc package

[0144] 84 Flow channel

[0145] 86 Check valve disc

[0146] 88 Preload spring

[0147] 90 Rebound spring

[0148] 92 Rebound adjustment device

[0149] 94 Rebound adjustment rod

[0150] 96 Recording area

[0151] 98 gas storage tanks

[0152] 100 valve 15.08.2025

[0153] 25 / 29

[0154] 102 Filling channel

[0155] 104 bore

[0156] 106 weld

[0157] 108 outer side wall 110 inner side wall

[0158] 112 creases

[0159] 114 Connecting block

Claims

August 15, 2025 26 / 29 Patent claims 1. A damping device (28) for a bicycle (10) comprising an outer tube (30) and an inner tube (32) arranged coaxially to it, wherein a compensation chamber (34) for receiving hydraulic fluids is formed between the outer tube (30) and the inner tube (32), and a piston (40) connected to a piston rod (42), which is arranged to be movable back and forth within the inner tube (32), wherein the interior of the inner tube (32) is divided by the piston (40) into a working chamber (44) remote from the piston rod and a working chamber (46) on the side of the piston rod, and wherein the damping device (28) comprises a valve assembly (50) and an adjusting device (55) for adjusting the damping of the valve assembly (50) in the rebound and / or compression stage, characterized in that the damping device (28) comprises a gas accumulator (98) which is arranged coaxially to and around the adjusting device (55). (55) is arranged around it.

2. Damping device (28) according to claim 1, wherein the gas storage (98) is located against the outer tube (30).

3. Damping device (28) according to one of the preceding claims, wherein the gas storage (98) is located at the adjusting device (55).

4. Damping device (28) according to one of the preceding claims, wherein the gas storage (98) has a C-shaped cross-section.

5. Damping device (28) according to one of the preceding claims, wherein the gas storage (98) is filled with a compressible gas, in particular nitrogen.

6. Damping device (28) according to one of the preceding claims, wherein the gas storage (98) has exactly one gas chamber. 8.2025 27 / 29 7. Damping device (28) according to one of the preceding claims, wherein the gas storage tank (98) has flexible walls (108, 110) which are preferably made of aluminium and / or a composite foil.

8. Damping device (28) according to one of the preceding claims, wherein the valve device (50) has a compression stage valve (52) for damping the piston movement in the compression stage and a rebound stage valve (54) for damping the piston movement in the rebound stage and wherein the adjusting device (55) has a compression stage adjusting device (68) for adjusting the damping of the compression stage valve (52) and a rebound stage adjusting device (92) for adjusting the damping of the rebound stage valve (54).

9. Damping device (28) according to claim 8, wherein the rebound adjustment device (92) has a hollow cylindrical rebound adjustment rod (94) and the compression adjustment device (68) has a compression adjustment rod (70) which is arranged at least partially inside the rebound adjustment rod (94).

10. Damping device (28) according to claim 9, wherein the gas storage (98) rests against the rebound adjustment rod (94).

11. Damping device (28) according to one of the preceding claims, wherein the gas storage tank (98) has a valve (100) for filling the gas storage tank (98).

12. Damping device (28) according to claim 11, wherein the damping valve device (28) has a closure package (48) which seals the outer tube (30) in a fluid-tight manner, and wherein the valve (100) is fixed inside the closure package (48).

13. Damping device (28) according to claim 7, wherein the walls (108, 110) are connected to each other by means of a weld (106) and wherein a connecting block (114) is arranged within the weld (106) to which the valve (100) is attached. 8.2025 28 / 29 14. Suspension fork (12) for a bicycle (10) comprising at least one damping device (28) according to one of the preceding claims.

15. Spring fork (12) according to claim 14, wherein the spring fork (12) has two legs (16, 18) each having a slide tube (24a, b) and a stanchion (26a, b), wherein the stanchion (26a, b) is at least partially slidably arranged within the respective slide tube (24a, b) and wherein a damping device (28) is attached in one or both legs (16, 18) and wherein the respective piston rod (42) is attached to the respective slide tube (24a, b).

16. Bicycle (10) comprising a suspension fork (12) according to claim 14 or 15 and / or comprising a rear wheel damper (14) with a damping device (28) according to one of claims 1 to 13.

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