Cushioning kit for walking assistance crutch

Abstract

The invention relates to a shock-absorbing kit for a kickstand comprising a shock-absorbing sub-assembly intended to be inserted into the upper tube (10) of this kickstand in replacement of its lower tube and comprising: - a stop block (110) having a bore provided to be passed through by a pin (32) of a first locking member (30) of said kickstand also passing through an upper pair of holes of said upper tube so as to ensure its fixing, - a lower leg made of plastic or composite material (150) having an oblong slot (151) provided to be passed through by the pin (202) of a second locking member (200) also passing through a lower pair of holes of said upper tube so as to ensure said leg can slide axially between two extreme positions high and low, and - a helical compression spring (120) intended to be arranged between said stop block and said leg.

Description

[0001] The present invention relates generally to the field of walking aids, particularly for medical use. It specifically relates to a shock-absorbing kit for a crutch, as well as a crutch incorporating such a shock-absorbing kit.

[0002] A crutch is generally defined as a medical device used to support all or part of a patient's body weight.

[0003] We mainly know of axillary or full-size crutches comprising a double support for the armpit and for the hand, as well as forearm or "English" crutches comprising a double support for the forearm and for the hand.

[0004] There figure 1 represents a classic forearm crutch 1 conforming to the most common model that has been commercially available for several decades and described in particular by document FR 2 679 441 A1.

[0005] In the remainder of this description and by convention, when referring to orientation qualifiers such as the terms "superior" or "inferior", these will be defined in relation to the normal position of use of such a crutch 1 by a user.

[0006] With reference to this figure 1 The crutch 1 includes: a cylindrical metal upper tube 10 provided with two pairs, upper and lower, axially spaced, of diametrically opposed circular holes 11 facing each other; a cylindrical metal lower tube 20 adapted to be partially inserted by telescopic sliding into said upper tube 10 and also provided with one or more pairs, spaced along its axis, of diametrically opposed circular holes facing each other (the latter not being visible on this figure 1 ) ; a first locking member 30 comprising an elastically deformable collar 31 clippable onto said upper tube and an internal radial pin 32 intended to pass through a pair of holes 11 of the upper tube 10 and a pair of holes in the lower tube 20 so as to axially lock the position of the latter in order to adjust the height of the kickstand.

[0007] The crutch 1 also includes a gripping head 40 fixedly fitted (typically by press fitting) onto the upper end of the upper tube 10 and made, for example, from a one-piece molding in plastic material.

[0008] This gripping head 40 classically includes a handle 41 extending in a direction substantially perpendicular to the axis of the upper tube 10, as well as a support for the forearm 42 extending obliquely upwards from this handle 41 and including at its upper end a cradle in an arc of a circle 43 serving as a support for this forearm.

[0009] The stand 1 also includes an anti-slip foot 50, designed to ensure contact with the ground, and mounted by fitting onto the lower end of the lower tube 20.

[0010] Furthermore, in order to limit friction between the upper metal tubes 10 and lower metal tubes 20 during its use, the stand 1 finally includes a plastic end piece 60 which is press-fitted onto the lower end of the upper tube 10, this end piece 60 being provided with a lower cylindrical collar 61 which rests against the lower edge of this upper tube 10 and whose internal diameter is slightly smaller than that of this same tube 10.

[0011] In use, a significant portion of the ground impact force of these crutches 1 is transmitted to the upper body of the user, particularly to the most sensitive areas such as the wrist, elbow and shoulder joints, which can lead to inflammatory pain for the user, especially when their condition requires them to use them for a long period.

[0012] In order to limit the transmission of this impact force to the ground for the user, some crutch models are equipped with an integrated damping device.

[0013] We know of crutches equipped with an external helical compression spring surrounding their lower tubular part and whose two upper and lower ends are respectively coupled to the upper tube and the lower tube.

[0014] It is understood that the pressure exerted on the upper tube causes a telescopic movement of the lower tube within the upper tube by putting the spring under stress.

[0015] Although they provide some attenuation of the impact force transmitted to the user and therefore greater comfort of use, these crutches generate particularly unpleasant operating noises for the user and pose a risk of pinching the fingers of young children playing near the user.

[0016] In addition, they represent a high purchase cost for users, which is generally added to that of a pair of "classic" crutches (i.e., without such shock-absorbing means) previously purchased.

[0017] This cost issue largely explains the poor commercial success of these shock-absorbing crutches.

[0018] In order to improve user comfort while limiting the necessary financial investment, recent years have seen the development of damping kits designed to be installed later in conventional crutches.

[0019] US document 2007 / 0277865 A1 discloses a shock absorber kit for a kickstand, including: a first stop collar intended to be fixedly mounted around a lower portion of the upper tube; a second stop collar intended to be fixedly mounted around a lower portion of the lower tube; and an external helical compression spring intended to be positioned between said first stop and said second stop with its two upper and lower ends which are respectively received in corresponding recesses provided in the first and second collars.

[0020] However, simply tightening the stop collars onto the upper and extension tubes creates a significant risk of the collars slipping along these tubes during use of the kickstand, potentially causing the user to fall. Furthermore, the problems related to operating noise and the risk of pinching the fingers of young children playing near the kickstand user persist.

[0021] US document 2013 / 0263903 A1 discloses another type of kickstand damping kit including: a piston cylinder comprising a bottom stop surface; a piston rod configured to move axially inside the piston cylinder; and a damper configured to be located on the piston rod and to abut against the stop surface to reduce the velocity of movement of the piston rod inside the piston cylinder.

[0022] This damping kit is configured to be fully installed in a removable manner within an internal space formed collectively by the upper and lower tubes of the kickstand.

[0023] More specifically, the piston cylinder and piston rod are each configured to be fixed respectively to the lower tube and upper tube when the shock absorber insert is removably mounted in the internal space, the shock absorber insert as a whole allowing mutual longitudinal movement between the upper and lower support elements.

[0024] In practice, however, this type of kit does not provide sufficient cushioning of impacts with the ground.

[0025] The present invention therefore aims to improve the situation.

[0026] For this purpose, it proposes a shock-absorbing kit for a walking assistance crutch of the type comprising an upper cylindrical tube having at least two pairs of axially spaced upper and lower opposite holes, a lower cylindrical tube capable of being partially inserted by telescopic sliding into said upper tube and also having at least one pair of opposite holes, as well as a first locking member having a pin intended to pass through said pair of holes in said upper tube and said pair of holes in said lower tube so as to axially lock the position of the latter.

[0027] The damping kit according to the invention is characterized in that it comprises a second locking member equipped with said pin and a damping sub-assembly intended to be inserted into said upper tube in replacement of said lower tube and comprising: a stop block having a diametrical bore intended to be passed through by the pin of said first locking member also passing through said upper pair of holes so as to ensure its fixing inside said upper tube, a lower cylindrical leg made of plastic or composite material having an oblong diametrical slot oriented axially and intended to be passed through by the pin of said second locking member also passing through said lower pair of holes so that said lower leg can slide axially vis-à-vis said upper tube between two extreme positions high and low in which this leg protrudes partially out of said upper tube, and a helical compression spring intended to be arranged between said stop block and said lower leg so as to elastically return said lower leg to its extreme low position.

[0028] With its intuitive and quick assembly, the damping kit according to the invention makes it possible to attenuate the impact force transmitted to the user while considerably limiting the operating noise compared to existing kits due to the plastic or composite material of its lower leg, so as to ensure much better user comfort.

[0029] Its relatively simple design also ensures a low production cost, making it affordable for everyone. Finally, the arrangement of its spring inside the upper tube prevents any risk of pinching the fingers of young children playing near the user.

[0030] In order to ensure a perfectly smooth and silent sliding of the lower jamb relative to the upper tube while limiting its mechanical wear in order to optimize its lifespan, this lower jamb or the contour of its oblong light will advantageously be made from a self-lubricating thermoplastic polymer resin possibly reinforced with synthetic and / or natural fillers.

[0031] In order to limit the mechanical wear of this lower jamb over time and to ensure a lifespan of several years, this self-lubricating thermoplastic polymer resin will preferably be chosen from polyoxymethylene (POM), polyethylene terephthalate (PETP), polyetheretherketone (PEEK) and polytetrafluoroethylene (PTFE).

[0032] In order to keep the longitudinal axis of the spring centered on the longitudinal axis of the upper tube so as to ensure optimal compression of this spring when using the kickstand, said shock absorber sub-assembly advantageously includes two hollow cylindrical caps, upper and lower, respectively fitted overlapping onto the upper and lower ends of the spring.

[0033] According to a preferred conformation, each of said caps comprises a cylindrical outer envelope covering a respective end portion of the spring, and a circular bottom wall against the inner face of which rests a corresponding end coil of this spring.

[0034] In order to limit friction with the upper tube so as to further reduce operating noise, improve its corrosion resistance and increase its service life, said compression spring is advantageously covered with an anti-friction coating.

[0035] In order to allow better adaptation of the stand equipped with said damping kit according to the invention to the need and / or morphology of the user, the damping sub-assembly preferably includes at least one adjustment element provided to be disposed, prior to the insertion of said lower leg inside said upper tube of the stand, in its oblong opening at the level of one or the other of its ends, so as to limit the sliding stroke of this lower leg.

[0036] According to a preferred conformation, each said adjustment organ has a width and depth substantially identical to those of said oblong light, so as to fill by correspondence of shape a portion of the end of the latter.

[0037] In order to ensure its axial retention vis-à-vis said lower jamb after its installation, each said adjustment member preferably includes at one of its transverse ends an interface lug intended to fit into one of the counterbores of complementary shape provided on said lower jamb at the periphery of the two ends of said light.

[0038] In order to ensure a more advanced level of personalization for the user, the damping kit according to the invention may advantageously include several said interchangeable adjustment elements of different lengths.

[0039] In order to increase the restoring force exerted by said spring so as to make the behavior of the kickstand firmer and therefore better suited to users of heavy build, said shock absorber sub-assembly preferably includes at least one cylindrical preload shim intended to be inserted entirely inside said upper tube, either between said stop block and said spring, or between said spring and said lower leg.

[0040] In order to ensure a more advanced level of personalization for the user, the damping kit according to the invention may advantageously include several interchangeable preload shims of different lengths.

[0041] With the aim of limiting the operating noise of the kickstand equipped with the damping kit according to the invention, caused in particular by repeated friction during the relative sliding between said damping sub-assembly and said upper tube of this kickstand, all the constituent elements of said damping sub-assembly, with the exception of said spring, are advantageously made of plastic or composite material.

[0042] Furthermore, and in order to facilitate the placement of said stop block inside said upper tube of the stand so that its diametrical drilling is aligned with the upper pair of holes of this tube to allow the insertion of the pin of said first locking member, the constituent elements of said shock absorber sub-assembly are suitable for being removably fixed to each other by means of snap-fit ​​fixing means.

[0043] The invention further relates, in a second aspect, to a walking assistance crutch comprising an upper cylindrical tube provided with at least two pairs, upper and lower, axially spaced, of opposite holes, a first locking member with a pin, and such a damping kit, of which said damping sub-assembly is inserted in said upper tube, the pin of said first locking member passing through said stop block and said upper pair of holes so as to ensure its fixing inside said upper tube, the pin of said second locking member passing through said lower cylindrical leg and said lower pair of holes so that said lower leg can slide axially vis-à-vis said upper tube between said extreme upper and lower positions.

[0044] The description of the invention will now be continued by a detailed description of several embodiments, given below by way of illustration but not limitation, with reference to the attached drawings, on which: there figure 1 represents a perspective view of an English-style walking aid, conforming to the model most commonly found on the market, and comprising a first clip-on ring with a pin for locking the position of the lower tube; the figure 2 is a perspective view of an assembly consisting of a classic crutch such as that of the figure 1 and a damping kit according to the invention, comprising in particular a damping sub-assembly inserted into the upper tube of this kickstand in place of its lower tube; the figure 3 represents a perspective view showing the shock absorber sub-assembly in its assembled configuration, ready to be inserted into the upper tube of the kickstand; the figures 4 et 5 are exploded perspective views from different angles of the damping kit according to the invention; figures 6 et 7 represent diametrical longitudinal cross-sectional views of the lower part of the entire figure 2 respectively in resting configuration and in fully retracted configuration; and the figure 8 is a perspective view of the upper cap that comprises the shock absorber subassembly; and; the figure 9 represents an exploded view of a preferred embodiment of the lower cap included in the shock absorber subassembly.

[0045] There figure 2 represents a perspective view of an assembly consisting of a classic English-type crutch 1 as described previously in support of the figure 1 but missing its lower tube 20, and a damping kit K according to the invention mounted on the upper tube 10 of this stand 1.

[0046] As can be seen on the figure 3 , the damping kit K according to the invention consists of a damping sub-assembly 100 intended to be introduced into the upper tube 10 in replacement of the lower tube 20, as well as a second locking member 200 comprising an elastically deformable collar 201 clippable onto the upper tube 10 and an internal radial pin 202 similar to that 32 of the first locking member 30.

[0047] We will now describe in detail the different constituent elements of the shock absorber sub-assembly 100.

[0048] This shock absorber sub-assembly 100 includes a cylindrical stop block 110 intended to be inserted entirely first inside the upper tube 10 and to be fixed there by means of the first locking member 30 which is included in the stand 1.

[0049] This stop block 110 thus has a diametrical through bore of cylindrical shape 111 whose diameter is slightly greater than that of the pin 32 of this first locking member 30.

[0050] As can be seen on the figures 6 et 7 , this hole 111 is intended to be passed transversely by this pin 32 which also passes through the upper pair of holes 11 of the upper tube 10 of the stand 1, so as to ensure the fixing of this stop block 110 inside this upper tube 10.

[0051] The shock absorber sub-assembly 100 also includes a helical compression spring 120 intended to be inserted fully inside the upper tube 10 after the stop block 110.

[0052] According to an advantageous feature of the invention, and as can be seen on the figures 3 And 4 , this shock absorber sub-assembly 100 further includes two hollow cylindrical caps upper 130 and lower 140 respectively fitted overlapping onto the upper and lower ends of the spring 120.

[0053] Each of these caps 130, 140 comprises an outer cylindrical envelope 131, 141 covering a respective end portion of the spring 120, and a circular bottom wall 132, 142 against the inner face of which rests a corresponding end coil of this spring 120.

[0054] The presence of these caps 130, 140 allows in particular to keep the longitudinal axis of the spring 120 centered on the longitudinal axis of the upper tube 10 of the kickstand 1 so as to guarantee optimal compression of this spring 120 when using this kickstand.

[0055] These caps 130, 140 also prevent any direct contact between the ends of this spring 120 and the inner face of the upper metal tube 10 of the stand 1, which limits the transmission of vibrations generated by this spring 120 to the user's arm via this upper tube 10 and reduces unwanted noise.

[0056] In order to increase the contact area between the inner faces of the bottom walls 132, 142 of these caps 130, 140 and the end coils of the spring 120 so as to improve its stability, the latter are advantageously closed and ground.

[0057] In order to limit friction, particularly with the upper tube 10, thereby reducing operating noise, improving its corrosion resistance and increasing its lifespan, this compression spring 120 can also be coated with an anti-friction coating, for example in polymer resin.

[0058] Other surface treatments such as shot blasting, passivation or chrome plating can also be applied to this 120 compression spring to further improve its lifespan and / or corrosion resistance.

[0059] In order to ensure sufficient cushioning for users of large build, its stiffness will advantageously be between 2 and 4 N / mm.

[0060] The shock-absorbing sub-assembly 100 further comprises a lower cylindrical leg 150 made of plastic or composite material, intended to be partially inserted inside the upper tube 10 of the kickstand after the spring 120, and onto the lower end of which the anti-slip foot 50 of this kickstand 1 is fitted as illustrated by the figures 2 , 6 et 7 .

[0061] This lower cylindrical jamb 150 has, in its upper part, an oblong diametrical light 151 oriented axially and whose width is slightly greater than the diameter of the pin 202 of the second locking member 200.

[0062] As can be seen on the figures 6 et 7 , this oblong light 151 is intended to be crossed transversely by this pin 202 also passing through the lower pair of holes 11 provided on the upper tube 10 of the support 1, so that this jamb 150 can slide axially vis-à-vis the upper tube 10 between two extreme positions high and low in which it protrudes partially out of this upper tube 10.

[0063] The external diameter of the lower leg 150 will be advantageously defined so that the gap with the internal diameter of the lower collar 61 of the end fitting 60 fitted onto the lower end of the upper tube 10 is less than 0.3 millimeters and preferably between 0.1 and 0.2 millimeters.

[0064] This small gap limits the lateral movement of the lower leg 150 during its axial sliding within the upper tube 10, thus ensuring greater user comfort. It also limits air leakage between this lower leg 150 and this collar 61, providing additional cushioning to that provided by the spring 120 during violent impacts with the ground (for example, in the event of a loss of balance by the user combined with a sudden recovery movement).

[0065] With the aim of ensuring additional damping to that exerted by the spring 120, it should be noted that the external diameter of the stop block 110 will also be advantageously defined so that the difference with the internal diameter of the upper tube 10 is less than 0.3 millimeters and preferably between 0.1 and 0.2 millimeters, in order to limit the air leakage between this stop block 110 and this upper tube 10.

[0066] In order to adapt to the size of the user, the damping kit according to the invention may advantageously include several interchangeable lower legs of different lengths.

[0067] Configured to elastically return this lower leg 150 to its lowest extreme position, the spring 120 will advantageously have sufficient length so that it remains partially compressed when this lower leg 150 reaches this lowest extreme position corresponding to the resting configuration of the kickstand 1 equipped with the kit according to the invention (see figure 6 ). This residual compression of the spring 120 allows a minimum restoring force to be exerted on the lower leg 150, ensuring secure support for the user upon contact with the ground and faster absorption of the impact force.

[0068] In order to allow for better adaptation of the kickstand 1 equipped with the damping kit K to the user's needs and / or body shape, the damping sub-assembly 100 preferably includes at least one adjustment element 160 designed to be positioned, prior to the insertion of the lower leg 150 into the upper tube 10 of the kickstand, in its oblong slot 151 at one or the other of its ends, so as to limit the sliding travel of this lower leg 150 as illustrated by the figure 7 .

[0069] Depending on its position at the upper or lower end of the oblong light 151 of the lower jamb 150, the addition of such an adjustment device 160 will thus allow the height of the support to be adjusted in its resting configuration or in its fully retracted configuration.

[0070] It should also be noted that the arrangement of such an adjustment element 160 at the lower end of this oblong opening 151 will limit the compression stroke of the spring 120 and thus increase its lifespan and limit operating noise.

[0071] As illustrated by the figures 4 et 5 , each adjustment organ 160 advantageously presents a width and depth substantially identical to those of the oblong opening 151, so as to fill by correspondence of form a portion of the end of the latter.

[0072] In order to ensure its axial retention vis-à-vis the lower jamb 150 after its installation, each adjustment member 160 preferentially includes at one of its transverse ends an interface lug 161 intended to fit into one of the counterbores of complementary shape 152 provided on this lower jamb 150 at the periphery of the two ends of the light 151.

[0073] The K damping kit according to the invention may advantageously include several interchangeable adjustment elements 160 of different lengths so as to ensure a more advanced level of customization for the user.

[0074] To allow for better adaptation of the kickstand equipped with the damping kit K to the user's needs and / or body shape, the damper sub-assembly 100 may also include at least one cylindrical preload spacer 170 intended to be fully inserted inside the upper tube 10 of the kickstand 1, either between the stop block 110 and the spring 120, or between this spring 120 and the lower leg 150 as illustrated by the figures 3 à 7 , so as to increase the residual compression of the spring 120 in the resting configuration of the kickstand 1 equipped with the kit according to the invention.

[0075] This increase in the residual compression of spring 120 will thus increase the restoring force exerted by this spring 120 so as to make the behavior of the kickstand firmer and therefore better suited to users of heavy build.

[0076] The K damping kit according to the invention may advantageously include several interchangeable 170 preload shims of different lengths so as to ensure a more advanced level of customization for the user.

[0077] In order to further limit the operating noise of the stand 1 caused in particular by the repeated friction exerted during the relative sliding between the shock absorber sub-assembly 100 and the upper tube 10 of this stand 1 during its use, all the constituent elements of this shock absorber sub-assembly 100 with the notable exception of the spring 120 shall advantageously be made of plastic or composite material.

[0078] In order to ensure perfectly smooth and silent sliding of the lower leg 150 relative to the upper tube 10, while limiting its mechanical wear to optimize its lifespan, the lower leg 150, or at least the outline of the oblong opening 151 of said lower leg 150, will advantageously be made from a self-lubricating thermoplastic polymer resin, possibly reinforced with synthetic and / or natural fillers. Accordingly, said lower leg 150 may include, for example, at the level of said oblong opening 151, a corresponding reinforcement in the form of a layer of self-lubricating thermoplastic polymer resin applied to the wall of said lower leg 150, thus forming said oblong opening 151.

[0079] In order to limit the mechanical wear of this lower jamb 150 over time and to ensure a lifespan of several years, this self-lubricating thermoplastic polymer resin will preferably be chosen from polyoxymethylene (POM), polyethylene terephthalate (PETP), polyetheretherketone (PEEK) and polytetrafluoroethylene (PTFE).

[0080] To reduce production costs for limited volumes, the 150 mm bottom jamb can be advantageously machined from a solid rod of standard diameter. For larger production volumes, this 150 mm bottom jamb could be produced directly using a plastic injection molding process.

[0081] Apart from this lower leg 150, the other plastic or composite elements constituting the shock absorber sub-assembly 100 (namely, the stop block 110, the caps 130, 140, the adjustment element(s) 160 and the preload shim(s) 170) will advantageously be obtained by a three-dimensional printing process, from a thermoplastic polymer resin possibly reinforced with synthetic and / or natural fillers.

[0082] The three-dimensional printing process used will, for example, be of the type by fused filament deposition (or FDM for "Fused Deposition Modeling" in English), by stereolithography (or SLA for "Stereolithography" in English), or by selective laser sintering (or SLS for "Selective Laser Sintering" in English).

[0083] In the case of larger production volumes, these elements could alternatively be produced by a plastic injection process.

[0084] In order to limit the mechanical wear of these parts over time and to ensure their lifespan of several years, this thermoplastic polymer resin will preferably be chosen from glycolized polyethylene terephthalate (PETG), polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), polyamide (PA), acrylonitrile styrene acrylate (ASA) and polycarbonate (PC).

[0085] Furthermore, and in order to facilitate the placement of the stop block 110 inside the upper tube 10 of the stand 1 so that its diametrical hole 111 is aligned with the upper pair of holes 11 of this tube 10 to allow the insertion of the pin 32 of the first locking member 30, the constituent elements of the shock absorber sub-assembly 100 are suitable for being removably fixed to each other by means of snap-fit ​​fixing means.

[0086] To secure the ends of the spring 120 to the caps 130 and 140, these snap-fit ​​fastening means comprise, on each cap 130, 140 and as can be seen on the figure 8 with reference to the upper cap 130, an inner annular ring 133 protruding from its bottom wall 132 being centered on its axis and intended to allow the forceful fitting of a corresponding end coil of the spring 120.

[0087] To ensure the fixing between two successive plastic or composite elements of this shock absorber sub-assembly 100, and as can be seen on the figures 4 et 5 , these fixing means include a pin P projecting from one end of the first element (such a pin P projecting in this case from the lower ends of the stop block 110, the lower cap 140 and the prestressing wedge 170) and intended to fit by force into a recess E of complementary shape made on the corresponding end opposite the second element (such a recess E being made in this case on the upper ends of the upper cap 130, the prestressing wedge 170 and the lower leg 150).

[0088] For ease of manufacturing by 3D printing, it will be noted in support of the figure 9that the lower cap 140 is advantageously made up of two separate pieces assembled together by press fitting, namely a first piece 140A identical to the upper cap 130 and a second piece 140B; the latter comprising a cylindrical base 140Ba intended to press fit into the inner housing defined by the inner annular ring of the first piece 140A, as well as a cylindrical finger 140Bb passing through the through imprint E made in the bottom wall of this first piece 140 and forming the pin P of this lower cap 140.

[0089] Numerous other embodiments are also possible, and it should be noted in this regard that the invention is not limited to the embodiments described and illustrated, but also encompasses all embodiments within the grasp of a person skilled in the art. In particular, it should be specified that the K damping kit according to the invention can also be mounted on crutches of different types, such as axillary or full-size crutches, provided that their configuration is compatible with the installation of such a kit.

Claims

1. Damping kit (K) for walking assistance crutch (1) of the type comprising an upper cylindrical tube (10) having at least two pairs of axially spaced upper and lower opposite holes (11), a lower cylindrical tube (20) suitable for being partially inserted by telescopic sliding into said upper tube (10) and also having at least one pair of opposite holes, as well as a first locking member (30) having a pin (32) intended to pass through said pair of holes (11) of said upper tube (10) and said pair of holes of said lower tube (20) so as to axially lock the position of the latter; characterized in thatsaid damping kit (K) includes a second locking member (200) having said pin (202) and a damping sub-assembly (100) intended to be inserted into said upper tube (10) in replacement of said lower tube (20) and comprising: - a stop block (110) having a diametrical hole (111) intended to be passed through said pin (32) of said first locking member (30) also passing through said upper pair of holes (11) so as to ensure its fixing inside said upper tube (10),- a lower cylindrical leg made of plastic or composite material (150) having an oblong diametrical slot (151) oriented axially and provided for passage by the pin (202) of said second locking member (200), which also passes through said lower pair of holes (11) so that said lower leg (150) can slide axially relative to said upper tube (10) between two extreme high and low positions in which said leg (150) protrudes partially out of said upper tube (10), and - a helical compression spring (120) intended to be arranged between said stop block (110) and said lower leg (150) so as to elastically return said lower leg (150) to its extreme low position.

2. Damping kit (K) according to claim 1, characterized in thatsaid lower jamb (150) or the contour of said oblong light (151) of said lower jamb (150) is made from a self-lubricating thermoplastic polymer resin possibly reinforced with synthetic and / or natural fillers.

3. Damping kit (K) according to claim 2, characterized in that said self-lubricating thermoplastic polymer resin is selected from polyoxymethylene (POM), polyethylene terephthalate (PETP), polyetheretherketone (PEEK) and polytetrafluoroethylene (PTFE).

4. Damping kit (K) according to any one of claims 1 to 3, characterized in that said shock absorber sub-assembly (100) comprises two hollow cylindrical caps, upper (130) and lower (140), respectively fitted overlapping onto the upper and lower ends of said spring (120).

5. Damping kit (K) according to claim 4, characterized in thatEach said cap (130, 140) comprises a cylindrical outer casing (131, 141) covering a respective end portion of said spring (120), and a circular bottom wall (132, 142) against the inner face of which rests a corresponding end coil of said spring (120).

6. Damping kit (K) according to any one of claims 1 to 5, characterized in that said compression spring (120) is covered with an anti-friction coating.

7. Damping kit (K) according to any one of claims 1 to 6, characterized in that the shock absorber subassembly (100) includes at least one adjustment member (160) provided to be disposed, prior to the insertion of said lower leg (150) inside said upper tube (10) of the stand, in its oblong opening (151) at the level of one or the other of its ends, so as to limit the sliding stroke of this lower leg (150).

8. Damping kit (K) according to claim 7, characterized in that each said adjustment member (160) has a width and depth substantially identical to those of said oblong light (151), so as to fill by correspondence of shape a portion of end of the latter.

9. Damping kit (K) according to claim 7 or 8, characterized in that Each said adjustment member (160) includes at one of its transverse ends an interface ear (161) intended to fit into one of the counterbores of complementary shape (152) provided on said lower jamb (150) at the periphery of the two ends of said light (151).

10. Damping kit (K) according to any one of claims 7 to 9, characterized in that It includes several interchangeable adjustment elements (160) of different lengths.

11. Damping kit (K) according to any one of claims 1 to 10, characterized in thatsaid shock absorber sub-assembly (100) includes at least one cylindrical preload shim (170) intended to be inserted entirely inside said upper tube (10), either between said stop block (110) and said spring (120), or between said spring (120) and said lower leg (150).

12. Damping kit (K) according to claim 11, characterized in that It includes several interchangeable prestressing shims (170) of different lengths.

13. Damping kit (K) according to any one of claims 1 to 12, characterized in that all the constituent elements of said shock absorber sub-assembly (100) with the exception of said spring (120) are made of plastic or composite material.

14. Damping kit (K) according to any one of claims 1 to 13, characterized in thatthe constituent elements of said shock absorber subassembly (100) are suitable for being removably fixed to one another by means of snap-fit ​​fixing means.

15. A walking aid comprising an upper cylindrical tube (10) having at least two axially spaced pairs of holes (11) at the top and bottom, a first locking member (30) having a pin (32), and a damping kit (K) according to any one of claims 1 to 14, wherein said damping subassembly (100) is inserted into said upper tube (10), the pin (32) of said first locking member (30) passing through said stop block (110) and said upper pair of holes (11) so as to secure it inside said upper tube (10), the pin (202) of said second locking member (200) passing through said lower cylindrical leg (150) and said lower pair of holes (11) so as to allow said lower leg (150) to slide axially relative to said upper tube (10) between said extreme high and low positions.

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