DEVICE FOR VEHICLE AIR SPRING, ACCESS CAP, FORK AND VEHICLE FEATURING SUCH A DEVICE

Abstract

TITLE OF THE INVENTION: DEVICE FOR VEHICLE AIR SPRING, ACCESS CAP, FORK AND VEHICLE COMPRISING SUCH A DEVICE (20) for a vehicle air spring (60) (80), the air spring comprising a piston (62) moving about an axis (21) in a cylinder (61) and an access cap (63) to the cylinder located on the axis of movement of the piston, the device being characterized in that it comprises: - at least one removable elastomeric foam wedge having a mounting relief with a reinforcement, - a support comprising a means for attaching to the access cap and the reinforcement, the reinforcement being shaped corresponding to the mounting relief of at least one said removable wedge and configured to receive at least one said removable wedge. Figure for the abstract: [Fig 6]

Description

Title of the invention: DEVICE FOR VEHICLE AIR SPRING, ACCESS CAP, FORK AND VEHICLE CONTAINING SUCH A DEVICE Technical field of the invention

[0001] The present invention relates to a device for a vehicle air spring, an access plug, a fork, and a vehicle incorporating such a device. In particular, the present invention relates to the field of shock absorbers for bicycles or motorcycles. State of the art

[0002] Bicycles and motorcycles are equipped with shock absorbers located in the fork associated with the front wheel. The damping is usually produced by a spring, an air spring, or a hydraulic spring.

[0003] The pneumatic springs include, in particular, a piston moving within a cylinder, the piston and cylinder forming a compression chamber. The compression chamber is closed by an access plug. The access plug allows, in particular, for maintenance and various adjustments to adapt the spring's capacity to the terrain and / or the user of the bicycle or motorcycle.

[0004] Pneumatic springs are also called "air springs." The spring force corresponds to the air pressure. This pressure depends on the amount of air relative to the chamber volume. The more the spring is compressed, the stiffer it becomes. For example, the pressure doubles when the compression is doubled. It is therefore a progressive spring, as its stiffening increases exponentially at the end of its travel. Such a spring can be defined by a so-called "progression curve," as shown in [Fig. 1].

[0005] The curve of an air spring is sometimes criticized for its lack of support in the so-called "travel" zone. For this reason, one or more hard, waterproof plastic shims are added to reduce the volume of the compression chamber. These shims are also called "tokens." To add or remove shims, the assembly plug has an assembly relief, and the shim has, on one side, a corresponding relief, and on the other side, the same relief as that of the access plug. Thus, a shim can be attached to the access plug, and additional shims can be attached to each other to form a tower.

[0006] The greater the number of shims, the more the volume of air in the compression chamber is reduced, resulting in a fork that stiffens more quickly.

[0007] If the number of shims is correct, the user will feel better support of the fork at mid-stroke.

[0008] The pneumatic spring is often associated with a negative spring, which can be made of steel or consist of a negative air chamber. This negative spring provides sensitivity to small shocks. Indeed, the pneumatic spring produces more friction, and its activation threshold is higher than that of a helical spring; hence the use of the negative spring to counteract this effect.

[0009] However, the user is limited to a choice of progression curves equal to the maximum number of wedges that the user can add, plus one, depending on the number of wedges added and must therefore adapt to the choice offered to him.

[0010] Such progression curves are represented in [Fig.1] on which the x-axis represents the stroke of the piston and the y-axis represents the force (in Newtons) required to reach this stroke at equivalent initial air pressure.

[0011] Curve 11 represents a pneumatic spring curve without a shim, curve 12 represents a pneumatic spring with one shim, curve 13 represents a pneumatic spring with two shims and curve 14 represents a pneumatic spring with three shims. Summary of the invention

[0012] The present invention aims to remedy all or part of these drawbacks.

[0013] It offers a shim support made of elastomeric foams assembled directly with the plug, the removal of the shims for their replacement, addition or deletion is therefore facilitated without damaging the piston cylinder. Brief description of the figures

[0014] Other advantages, purposes and particular features of the invention will become apparent from the following non-limiting description of at least one particular embodiment of the device that is the subject of the present invention, with reference to the accompanying drawings, in which:

[0015] [Fig. 1] represents, schematically and in perspective, an example of the progression curves of a prior art device

[0016] [Fig.2] represents, schematically and in cross-section, a first embodiment of a device that is the subject of the present invention,

[0017] [Fig.3] represents, schematically and in view from below, the first embodiment of a device that is the subject of the present invention,

[0018] [Fig.4] schematically represents, in front view, different embodiments of a support for a device that is the subject of the present invention,

[0019] [Fig.5] schematically represents, in a bottom view, two wedge profiles of the device that is the subject of the present invention,

[0020] [Fig. 6] schematically represents, in front view, a pneumatic spring comprising the device that is the subject of the present invention, and

[0021] [Fig.7] schematically represents, in front view, a fork comprising the device that is the subject of the present invention, and

[0022] [Fig.8] represents, schematically, and in front view, a vehicle comprising the device which is the subject of the present invention. Description of the implementation methods

[0023] The present description is given by way of non-limiting grammar, each feature of an embodiment being able to be advantageously combined with any other feature of any other embodiment.

[0024] The expression "and / or", as used in this document and in the claims, shall be understood as meaning "either or both" of the elements thus joined, that is, elements that are present conjunctively in some cases and disjunctively in others. The multiple elements listed with "and / or" shall be interpreted in the same way, that is, "one or more" of the elements thus joined. Other elements may be present, other than the elements specifically identified by the "and / or" clause, whether or not they are related to those specifically identified elements.Thus, by way of non-limiting example, a reference to "A and / or B", when used in conjunction with an open language such as "including", may refer, in one embodiment, to A only (possibly including elements other than B); in another embodiment, to B only (possibly including elements other than A); in yet another embodiment, to A and B (possibly including other elements); etc.

[0025] As used in this description, the expression "at least one," with reference to a list of one or more elements, should be understood as meaning at least one element chosen from one or more elements in the list of elements, but not necessarily including at least one of each element specifically enumerated in the list of elements and not excluding any combination of elements in the list of elements. This definition also allows for the optional presence of elements other than the elements specifically identified in the list of elements to which the expression "at least one" refers, whether or not they are related to those specifically identified elements.Thus, by way of non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B", or, equivalently, "at least one of A and / or B") may refer, in one embodiment, to at least one, possibly including more than one, A, without B present (and possibly including elements other than B); in another embodiment, to at. minus one, possibly including more than one, B, without A present (and possibly including elements other than A); in yet another embodiment, at least one, possibly including more than one, A, and at least one, possibly including more than one, B (and possibly including other elements); etc.

[0026] In the description below, all transitive expressions such as "comprising", "including", "carrying", "having", "containing", "implying", "holding", "composed of", and others, are to be understood as open, that is, as meaning "including, but not limited to". Only the transitive expressions "consisting of" and "consisting essentially of" are to be understood as closed or semi-closed transitive expressions, respectively.

[0027] Figures 2 and 3 show a first embodiment of a device 20 of the present invention for a pneumatic spring 60 of a vehicle 80.

[0028] Figure 6 shows an embodiment of a pneumatic spring 60 comprising a piston 62 moving about an axis 21 in a cylinder 61 and an access plug 63 for the cylinder 61 located on the axis of movement 21 of the piston 62. Pneumatic springs 60 are known to those skilled in the art. The piston 62 and the cylinder 61 define a space called the "compression chamber" 66, into which pressurized air is inserted. The air pressure when the piston is at bottom dead center defines the elastic characteristics of the spring 60.

[0029] It should be noted from the outset that the figures are not to scale.

[0030] Device 20 comprises: - at least one wedge, 28, 30, 32, 34, removable elastomeric foam having an assembly relief, 29, 31, 33, 35, with a reinforcement 25, - a support 22 comprising a means of fixing, 23 and 24, to the access plug 63 and the frame 25, the frame 25 being of shape 27 corresponding to the assembly relief, 29, 31, 33, 35, of at least one said wedge, 28, 30, 32, 34, removable and configured to receive at least one said removable wedge.

[0031] In the embodiment shown in [Fig. 2], the assembly relief, 29, 31, 33, 35, of each wedge, 28, 30, 32, 34, is a truncated right cylinder with a circular directrix. Each wedge, 28, 30, 32, 34, has a truncated right cylinder shape with a circular directrix concentric to the directrix of the assembly relief, 29, 31, 33 or 35, and a diameter greater than the diameter of the directrix of the assembly relief, 29, 31, 33 or 35. Each wedge, 28, 30, 32, 34, therefore has a washer shape. Thus, a peripheral shape and an internal shape corresponding to the assembly relief can be defined.

[0032] The axis 21 can also be considered as an axis of symmetry for the wedges, the reinforcement and the means of fixing, or as an axis of revolution for these same elements.

[0033] This embodiment is shown by way of example, and other types of generators can be used to represent the peripheral and internal shapes, for example, a polygon or an ellipse. The peripheral and internal shapes can be different. Preferably, the peripheral shape circumscribes the internal shape.

[0034] Preferably, the center of gravity of the guide curve of the assembly relief, 29, 31, 33, 35, and of the peripheral shape are aligned. When the device 20 is assembled to an access plug 63 and inserted into the compression chamber 66 of the air spring 60, said centers of gravity are on the axis of movement 21 of the piston 62.

[0035] In embodiments (not shown), the assembly relief , 29, 31, 33, 35, comprises a plurality of truncated straight cylinders, preferably parallel, each truncated cylinder corresponding to an armature.

[0036] In [Fig. 5], two profiles, 50 and 51, different from shims 28, are observed. Profile 50 corresponds to the shim described above opposite [Fig. 2]. Profile 51 has at least one groove 52 on its peripheral shape. Each groove 52 can be of any profile known to those skilled in the art, for example, square, rectangular, arc-shaped, or polygonal. Each groove 52 has its axis parallel to the axis of movement of the piston 21. In other words, each groove 52 extends along an axis parallel to the axis of movement of the piston 21, the profile corresponding to an empty space along said axis.

[0037] It can be seen in [Fig. 5] that the profile 51 has four grooves 52 equidistant from each other. More generally, whatever the number of grooves in a wedge, 28, 30, 32, 34, the grooves are distributed around the periphery of the wedge, 28, 30, 32, 34.

[0038] In the embodiment shown in Figures 2 and 3, each shim, 28, 30, 32, 34, may have a different density, as indicated by the different dashed lines used. Furthermore, in the embodiment shown in Figures 2 and 3, the shims, 28, 30, and 32, have the same dimension along the axis 21, hereinafter referred to as "thickness," with shim 34 having a thickness less than that of one of the shims, 28, 30, or 32.

[0039] In preferred embodiments: - Each shim, 28, 30, 32 and 34, can have a thickness chosen from one of the following values: 12.5mm, 25mm, 37.5mm and 50mm, - each wedge, 28, 30, 32 and 34, is made of elastomer foam with a compressive strength between 14 and 3640 kPa, preferably chosen from the following values: 14, 22, 63, 82, 170, 330, 620, 840, 1050, 1241, 3640.

[0040] Preferably, each wedge, 28, 30, 32 and 34, is made of elastomeric foam of the brand “Regufoam” ®.

[0041] Preferably, the reinforcement 25 has a dimension along the axis 21. The number of shims, 28, 30, 32 and 34, that the reinforcement can receive is such that the sum of the thicknesses of the shims, 28, 30, 32 and 34 is less than the dimension of the reinforcement along the axis 21.

[0042] Preferably, the dimension of the armature 25 along the axis 21 is such that the distance between the distal end of the armature 25 and the piston is always greater than zero millimeters. In other words, the armature 25 and the piston do not come into contact.

[0043] The device 20 comprises the frame 25. The frame 25 has a truncated cylindrical shape 27 with a predefined guide curve corresponding to the internal shape of each wedge 28, 30, 32, 34. In Figures 2 and 3, the guide curve is a circle. However, similarly to what was described above concerning the wedges, the guide curve can be of any shape known to those skilled in the art.

[0044] Preferably, the reinforcement 25 has an axis passing through the center of gravity of the direction curve. The axis of the reinforcement 25 is preferably coincident with the axis 21.

[0045] In preferred embodiments, the armature 25 is traversed by an orifice 26 with an axis parallel to the axis 21 of movement of the piston 62. Such an orifice allows, when the spring is pressurized, for air to be injected through the access plug 63 into the compression chamber 66. The orifice 26 is a circular bore, with its axis coinciding with the axis 21, for example.

[0046] In preferred embodiments, the frame 25 includes a locking means, 36 and 37, for each wedge, 28, 30, 32, 34, removable against the frame 25, each wedge, 28, 30, 32, 34, removable being locked along the frame 25 between the locking means, 36 and 37, and the fixing means 22.

[0047] In Figures 2 and 3, such a locking means has the form of a groove 36 on the frame, in which a circlip 37 is assembled. These embodiments facilitate the removal and installation of this fastening means to add or remove one or more shims. Furthermore, this helps to limit the weight of the added parts.

[0048] The locking means is configured to limit the translational movement of each wedge, 28, 30, 32 or 34 to the dimension of the reinforcement 25 along the axis 21.

[0049] In variants, the locking means is a bolt formed by means of a thread on the end of the frame 25 furthest from the fastening means 22 called the "distal end" and a nut.

[0050] In embodiments shown in [Fig.4], the frame 25 has at least one concave relief, 41, 42, 43 or 45, configured for the passage of air between at least one wedge, 28, 30, 32, 34 and the frame 25. [Fig.4] shows two embodiments, 40 and 41, of supports which are the subject of the present invention.

[0051] In embodiment 40, shown on the left of [Fig. 4], the reinforcement has several holes, 41, 42, and 43, passing through the reinforcement along an axis perpendicular to axis 21. Although embodiment 40 shows three holes, the reinforcement could have more or fewer holes. Preferably, the holes, 41, 42, and 43, are equidistant from each other.

[0052] In embodiment 41, shown to the right of [Fig.4], the reinforcement is traversed by a helical groove 45 with axis 21.

[0053] The fastening means 22 is assembled to the frame 25. Preferably, the fastening means 22 has a truncated right-hand cylinder shape corresponding to the cylinder of the pneumatic spring. For example, the fastening means 22 has a truncated right-hand cylinder shape with a circular direction concentric to the direction of the frame 25.

[0054] This embodiment is represented by way of example and other types of generators can be used to represent the peripheral shape of the fastening means, for example, a polygon, or an ellipse.

[0055] Preferably, when the device 20 is assembled to an access plug 63 and inserted into the compression chamber 66 of the air spring 60, the center of gravity of the direction curve is on the axis of displacement 21 of the piston 62.

[0056] Preferably, the fastening means 22 is configured to form a sliding connection with an axis perpendicular to the axis of movement 21 of the piston 61 with the access plug 63.

[0057] In particular, figures 2 and 3 show a T-shaped groove, 23 and 24, passing through the fastening means 22 to the axis 21. Preferably, the groove 23 and 24 opens into a circular arc cavity with a T-shaped cross-section. The cavity has dimensions greater than those of the groove.

[0058] Such a form allows: - that it is assembled to a stud 65 present on the access plug 63 is known to a person skilled in the art, - to create friction between the stud 65 and the groove, 23 and 24, but to leave the groove free to rotate in the cavity.

[0059] The fastening means 22 and the frame 25 are preferably machined from a single piece. Such a piece is made of steel or aluminum, for example.

[0060] As can be seen from Figures 2, 3 and 6, the user performs the following steps to assemble the device 20 to a pneumatic spring 60: - selection of at least one shim, 28, 30, 32, 34, defined by its material and thickness, - placement of each shim, 28, 30, 32, 34, selected on the frame 25 by fitting it from the distal end to the fastening means 22, - positioning of a circlip 37 in the groove 36, - sliding of the stud 65 of the access plug 63 in the groove 23 and 24 until it reaches the cavity.

[0061] The plug 63, equipped with the device 20, is then assembled in the pneumatic spring in a manner known to those skilled in the art, and the adjustments known to those skilled in the art are made. For example, it can be seen in [Fig. 6] that the plug has a thread 64 corresponding to a tapped hole in the cylinder 61.

[0062] To replace, add or remove a shim, 28, 30, 32, and 34, the user removes the circlip 37 from the groove 36, performs the desired action and replaces the circlip 37 in the groove 36.

[0063] Figure 6 shows, from the plug 63 to the piston 62, along the axis 21 of piston movement: - the plug 63, fitted with a threaded shaft, 64 having a stud 65 at its end, - the device 20, comprising the fixing means 22, the stud 65 being assembled in the groove, 23 and 24, then the frame 25 surrounded by two shims, the circlip 37 and the groove are not shown, - around the threaded part 64 of the plug 63 and the device 20, is the cylinder 61, ending with the piston 62.

[0064] In some embodiments (not shown), the device 20 is integrated into the access plug 63; in other words, the device 20 and the access plug 63 form a single piece. The device 20 therefore does not have a means for attaching it to the plug. In other words, the access plug 63 comprises: - at least one wedge, 28, 30, 32, 34, removable elastomeric foam having an assembly relief, 29, 31, 33, 35, with a reinforcement 25, - a support, 22, 25, comprising the frame 25, the frame being of a shape corresponding 27 to the assembly relief of at least one said removable wedge and configured to receive at least one said removable wedge.

[0065] Figure 7 shows a bicycle fork 70 for a bicycle 80 comprising an air spring 60, the air spring 60 having a piston 62 moving about an axis in a cylinder 61 and an access plug 63 to the cylinder 61 located on the axis of movement of the piston 62, and at least one device 20 of the present invention. The fork 70, without the device 20, is known to those skilled in the art.

[0066] We observe, in [Fig.8], a bicycle 80 comprising a fork 70 comprising an air spring 60, the air spring 60 comprising a piston 62 moving along an axis in a cylinder 61 and an access plug 63 to the cylinder 61 placed in the axis of movement of the piston 62 and at least one device 20 of the object of the present invention.

[0067] Advantages provided

[0068] To this end, according to a first aspect, the present invention relates to a device for a vehicle air spring, the air spring comprising a piston moving about an axis in a cylinder, and an access plug for the cylinder placed on the axis of movement of the piston, the device comprising: - at least one removable elastomeric foam wedge with a raised area for assembly with a frame, - a support comprising a means of attachment to the access plug and the frame, the frame being of a shape corresponding to the assembly relief of at least one said removable wedge and configured to receive at least one said removable wedge.

[0069] Thanks to these arrangements, the elastomer foam shims are directly attached to the access plug. It is therefore easy to replace or remove the shims by removing the access plug.

[0070] Furthermore, the foam material is such that when the pressure in the compression chamber changes, the elastomer structure undergoes a substantially elastic deformation associated with viscous behavior. The presence of both elastic and viscous effects, which vary according to the material chosen and the size and / or shape of the elastomer body, thus makes it possible to adjust the behavior of the air spring according to requirements, particularly in the case of bicycle or motorcycle forks.

[0071] Finally, several shims made of different elastomer foams can be positioned on the frame allowing very fine adjustment of the behavior of the pneumatic spring according to the terrain and the user of the vehicle.

[0072] With sealed plastic wedges, the user feels a significant hardness during an impact or shock due to the roughness of the ground, whereas the present invention allows one to feel a good grip on the ground while limiting the effect of the impact.

[0073] In some embodiments, the armature is traversed by an orifice with an axis parallel to the axis of movement of the piston.

[0074] Thanks to these arrangements, it is possible to inject air into the piston through the access plug and the armature to adjust the capacities of the pneumatic spring.

[0075] In embodiments, the frame has a truncated right cylinder shape with a predefined guide curve, the assembly relief of each removable wedge has a corresponding truncated right cylinder shape with a predefined guide curve.

[0076] Thanks to these arrangements, the wedges can be assembled by sliding them around the frame.

[0077] In embodiments, the frame includes a means for locking each removable wedge against the frame, each removable wedge being locked along the frame between the locking means and the fixing means.

[0078] Thanks to these arrangements, the wedges remain positioned on the frame, regardless of the shocks received by the pneumatic spring.

[0079] In some embodiments, the armature includes at least one concave relief.

[0080] Thanks to these arrangements, the passage of air is facilitated during the expansion and compression phases of the pneumatic spring.

[0081] In embodiments, the fastening means has a truncated straight cylinder shape corresponding to the cylinder of the pneumatic spring.

[0082] Thanks to these arrangements, the support is inserted into the cylinder.

[0083] In embodiments, the fastening means is configured to form a sliding connection with an axis perpendicular to the axis of movement of the piston with the access plug.

[0084] Thanks to these provisions, in the event of shocks to the air spring, in particular if it is integrated into a fork or shock absorber, the support is locked in position on the access plug once the support is assembled to the access plug and inserted into the cylinder.

[0085] In embodiments, at least one shim has a washer shape and has at least one peripheral groove along an axis parallel to the axis of movement of the piston.

[0086] Thanks to these arrangements, air can easily circulate around the wedges in the compression chamber.

[0087] According to a second aspect, the present invention relates to an access plug for a vehicle air spring, the air spring comprising a piston moving about an axis in a cylinder, the access plug to the cylinder being placed on the axis of movement of the piston, and comprising: - at least one removable elastomeric foam wedge with a raised area for assembly with a frame, - a support comprising the reinforcement, the reinforcement being of a shape corresponding to the assembly relief of at least one said removable wedge and configured to receive at least one said removable wedge.

[0088] The purposes, advantages and special characteristics of the access plug which is the subject of the present invention being similar to those of the device which is the subject of the present invention, they are not recalled here.

[0089] According to a third aspect, the present invention relates to a vehicle fork comprising an air spring, the air spring comprising a piston moving along an axis in a cylinder and an access plug to the cylinder placed in the axis of movement of the piston and at least one device of the present invention or an access plug of the present invention.

[0090] The purposes, advantages and special characteristics of the fork which is the subject of the present invention being similar to those of the device which is the subject of the present invention, they are not recalled here.

[0091] According to a fourth aspect, the present invention relates to a vehicle comprising a fork having an air spring, the air spring having a piston moving along an axis in a cylinder and an access plug to the cylinder placed in the axis of movement of the piston and at least one device of the present invention or an access plug of the present invention.

[0092] The purposes, advantages and special characteristics of the vehicle which is the subject of the present invention being similar to those of the device which is the subject of the present invention, they are not recalled here.

Claims

Demands

1. Device (20) for a vehicle (80) air spring (60), the air spring comprising a piston (62) moving along an axis (21) in a cylinder (61) and an access plug (63) to the cylinder placed on the axis of movement of the piston, the device being characterized in that it comprises: - at least one removable elastomer foam wedge (28, 30, 32, 34) having an assembly relief (29, 31, 33, 35) with a frame (25), - a support (22, 25) comprising a means of attachment (22) to the access plug and the frame (25), the frame being of a shape corresponding (27) to the assembly relief of at least one said removable wedge and configured to receive at least one said removable wedge.

2. Device (20) according to claim 1, in which the armature (25) is traversed by an orifice (26) with an axis parallel to the axis (21) of displacement of the piston (62).

3. Device (20) according to any one of claims 1 or 2, wherein the frame (25) has a truncated right cylinder shape with a predefined guide curve, the assembly relief (29, 31, 33, 35) of each removable wedge (28, 30, 32, 34) has a corresponding truncated right cylinder shape with a predefined guide curve.

4. Device (20) according to any one of claims 1 to 3, wherein the frame (25) comprises a locking means (36, 37) for each removable wedge (28, 30, 32, 34) against the frame, each removable wedge being locked along the frame between the locking means and the fixing means (22).

5. Device (20) according to any one of claims 1 to 4, wherein the frame (25) has at least one concave relief (41, 42, 43, 45).

6. Device (20) according to any one of claims 1 to 5, wherein the fastening means (22) has a truncated straight cylinder shape corresponding to the cylinder (61) of the pneumatic spring (60).

7. Device (20) according to any one of claims 1 to 6, wherein the fastening means (22) is configured to form a sliding connection with axis perpendicular to the axis (21) of movement of the piston (62) with the access plug (63).

8. Device (20) according to any one of claims 1 to 7, wherein at least one shim (28, 30, 32, 34) has a washer shape and has at least one peripheral groove (52) along an axis parallel to the axis (21) of movement of the piston (62).

9. Access plug (63) for air spring (60) of vehicle (80), the air spring comprising a piston (62) moving along an axis (21) in a cylinder (61), the access plug (63) to the cylinder being placed on the axis of movement of the piston, and being characterized in that it comprises: - at least one removable elastomer foam wedge (28, 30, 32, 34) having an assembly relief (29, 31, 33, 35) with a reinforcement (25), - a support (22, 25) comprising the reinforcement (25), the reinforcement being of a shape corresponding (27) to the assembly relief of at least one said removable wedge and configured to receive at least one said removable wedge.

10. Fork (70) for vehicle (80) comprising an air spring (60), the air spring comprising a piston (62) moving about an axis (21) in a cylinder (61) and an access plug (63) to the cylinder placed in the axis of movement of the piston and at least one device (20) according to any one of claims 1 to 8 or an access plug according to claim 9.

11. Vehicle (80) comprising a fork (70) comprising an air spring (60), the air spring comprising a piston (62) moving about an axis (21) in a cylinder (61) and an access plug (63) to the cylinder placed in the axis of movement of the piston and at least one device (20) according to any one of claims 1 to 8 or an access plug according to claim 9.