SHOCK ABSORBER CONNECTED THERETO

BACKGROUND

The invention relates to a shock absorber . Furthermore , the invention relates to an assembly of a seat construction and a shock absorber connected thereto .

A shock absorber is known in the prior art . The known shock absorber comprises an absorbing cylinder with an absorbing chamber defined therein and configured for holding an absorbing fluid; an absorbing piston rod having a first piston rod end and a second piston rod end, opposite to the first piston rod end, wherein the second piston rod end is arranged within the absorbing chamber and the first piston rod end outside the absorbing chamber ; and an absorbing piston arranged at the second piston rod end of the absorbing piston rod . The first piston rod end of the absorbing piston rod may be provided with a first connector configured for being connected to an external obj ect , and a second connector may be provided on top of the absorbing chamber and may be configured for being connected to an external obj ect , which may differ from the external obj ect to which the first connector may be connected .

SUMMARY OF THE INVENTION

A disadvantage of the known shock absorber, for example when connected to a seat construction, in particular below a seat , is that the higher the weight of the person sitting on the seat, the lower the height of the seat . As a result , a heavier person disadvantageously may have a lower seat height .

Additionally, the spring of the known shock absorber is preloaded by applying a predetermined preload force to the spring, which predetermined preload force is disadvantageously applied regardless of the person sitting on the seat to which the shock absorber is applied . In other words , the predetermined preload force may be intended for persons of a predetermined length, such that the known shock absorber is not functioning properly for persons with another length .

It is an obj ect of the present invention to ameliorate or to eliminate one or more disadvantages of the known prior art , to provide an improved shock absorber or to at least provide an alternative shock absorber .

According to a first aspect , the invention provides a shock absorber, comprising : an absorbing cylinder with an absorbing chamber defined therein and configured for holding an absorbing fluid, wherein the absorbing cylinder has a first cylinder end and a second cylinder end, opposite to the first cylinder end in the longitudinal direction thereof ; an absorbing piston rod having a first piston rod end and a second piston rod end, opposite to the first piston rod end, wherein the second piston rod end is arranged within the absorbing chamber, the first piston rod end outside the absorbing chamber and the absorbing piston rod passes through the first cylinder end of the absorbing cylinder ; an absorbing piston arranged at the second piston rod end of the absorbing piston rod; and an absorbing spring arranged partially around the absorbing piston rod and the absorbing cylinder, wherein the shock absorber comprises a height adj usting mechanism arranged on the second cylinder end of the absorbing cylinder and comprising, at the end of the height adj usting mechanism facing away from the absorbing cylinder, a connector configured for being connected to an external obj ect, wherein the height adj usting mechanism is configured for adj usting the height of the connector by moving the connector away from or towards the second end of the absorbing cylinder in a direction parallel to the longitudinal direction of the absorbing cylinder, wherein the shock absorber further comprises a preloading mechanism configured for applying a preloading force onto the absorbing spring, wherein the height adj usting mechanism and the preloading mechanism are operatively connected to each other, such that adj usting the height of the connector results in adj ustment of the preloading force applied to the absorbing spring by the preloading mechanism.

The shock absorber according to the invention, for example, may be mounted to the fixed side of a seat construction, direct or via a link system, at the first piston rod end thereof , which fixed side may be intended to be mounted to a vessel , such as a boat, car, truck, etc . , wherein the moving side of the seat construction ( seat side ) may be connected to the connector of the height adj usting mechanism. During use , the seat of the seat construction may be used by a number of di fferent persons , whom each have a dif ferent length . The height adj usting mechanism advantageously enables the current user to adj ust the height of the seat to his own desires . For example , a longer person usually tends to adj ust the seat to a higher position in comparison with a shorter person . Due to the operative connection between the height adj usting mechanism and the preloading mechanism, adj ustment of the height of the connector, and thereby of the seat , results in adj ustment of the preload force applied to the absorbing spring . For example, the higher the connector, i . e . the further the connector is away from the second piston rod end, the higher the preload force applied to the absorbing spring . According to the inventors , a longer person usually has a higher weight in comparison with a shorter person . An advantage of the shock absorber, therefore, is that adj ustment of the height of the connector and thereby the seat on basis of the length of a person results in adj ustment of the preload force applied to the absorbing spring, wherein the weight of the person is taken into account .

In an embodiment , the connector is moveable between a high position and a low position by the height adj usting mechanism, wherein moving the connector towards the high position results in increase of the preload force applied to the absorbing spring, and moving the connector towards the low position results in decrease of the preload force applied to the absorbing spring . According to this embodiment the preload force applied to the absorbing spring increases when the connector is moved towards the high position, such that when a longer person sits on the seat , who usually is heavier than a shorter person, a higher preload force is applied to the absorbing spring in comparison with the connector moving towards the low position . This is advantageous as the preload force may be adj usted in dependence of the length and thereby the weight of a person sitting on the seat .

In an embodiment , the height adj usting mechanism comprises : a first adj usting chamber; a height adj usting rod having a first end and a second end, opposite to the first end, wherein the first end is located within the first adj usting chamber and the second end, at which the connector is provided, is located outside the first adj usting chamber ; and a first closed piston arranged at the first end of the height adj usting rod and dividing the first adj usting chamber into a first lower chamber portion and a first upper chamber portion, wherein the first lower chamber portion is in fluid communication with the absorbing chamber . Preferably, the closed piston within the first adj usting chamber is moveable therein in a direction parallel to the longitudinal direction of the absorbing cylinder . In a further embodiment, the first adj usting chamber has an inner surface and the first closed piston has a circumferential outer surface , wherein the inner surface of the first adj usting chamber and the circumferential outer surface of the closed piston are in contact with each other in a sealing manner, such that a fluid flow between the first lower chamber portion and the first upper chamber portion is prevented .

In an embodiment, the height adj usting mechanism comprises a second adj usting chamber arranged next to the first adj usting chamber such that the height adj usting rod extends through the second adj usting chamber, and a second closed piston arranged at the height adj usting rod and within the second adj usting chamber, wherein the second closed piston divides the second adj usting chamber into a second lower chamber portion and a second upper chamber portion .

In an embodiment, the second adj usting chamber has an inner surface and the second closed piston has a circumferential outer surface, wherein the inner surface of the second adj usting chamber and the circumferential outer surface of the second closed piston are in contact with each other in a sealing manner, such that a fluid flow along the second closed piston and between the second lower chamber portion and the second upper chamber portion is prevented .

In an embodiment, a connecting channel is provided between the second lower chamber portion and the second upper chamber portion for allowing a flow of fluid therebetween . In a further embodiment thereof , an operating closure, such as an operating valve, is provided, at least partially, within the connecting channel , which operating closure is configured to be moved between an open position, in which a flow of fluid between the second lower chamber portion and the second upper chamber portion is allowed, and a blocking position, in which a flow of fluid between the second lower chamber portion and the second upper chamber portion is blocked . The second adj usting chamber, on the one hand, may be used for maintaining the height of the seat , since movement of the second closed piston within the second adj usting chamber is blocked when no fluid flow is possible when the operating closure, in particular the operating valve, is in the blocking position thereof . On the other hand, moving the operating closure, in particular the operating valve, into the open position allows the height of the seat to be adj usted as fluid may flow from the second lower chamber portion to the second upper chamber portion, or vice versa, which allows the second closed piston to move upwards or downwards within the second adj usting chamber . Therefore, the operating closure may be used for enabling or preventing adj ustment of the height of the connector and thereby of the preload force applied to the absorbing spring .

In an embodiment, the height adj usting mechanism comprises a height operator configured for operating the height adj usting mechanism in order to adj ust the height of the connector . In an embodiment thereof , the height operator is operatively connected to the operating closure . Preferably, the height operator comprises a height operating lever that is operationally connected to the operating closure, which height operating lever is configured to be moved between an open position, in which the operating closure is in the open position, and a blocking position, in which the operating closure is in the blocking position . Preferably a biasing spring is provided that is operationally connected to the height operating lever, which biasing spring biases the height operating lever into the blocking position . The height operating lever allows a user to move the operating valve into the open position thereof by actuating the height operating lever, such that the height of the seat may be changed by operating the height operating lever . According to this embodiment, operation of the height adj usting mechanism is relatively simple and may be performed advantageously by a user themselves in a relatively easy manner .

In an embodiment , the shock absorber comprises a pressure cylinder with a pressure chamber defined therein, wherein the pressure chamber is in fluid communication with the absorbing chamber . The pressure cylinder with the pressure chamber is provided for controlling the pressure within the absorbing chamber in dependence of the absorbing piston rod moving further into or out of the absorbing chamber .

In an embodiment, the connecting channel is in fluid communication with the pressure chamber within the pressure cylinder . During use, the temperature of the fluid within the second adj usting chamber may increase, for example, due to the second closed piston moving therein . Due to the connecting channel being in fluid communication with the pressure cylinder, fluid may run, preferably via a channel valve provided between the pressure chamber and the connecting channel , into the pressure chamber such that it advantageously may be prevented that the pressure within the second adj usting chamber becomes too high . In an embodiment, the shock absorber comprises a spring cuff arranged around a part of the absorbing cylinder and the absorbing spring arranged partially within the spring cuff and around the absorbing cylinder and the absorbing piston rod, and extending between the spring cuf f and the first piston rod end . In an embodiment thereof , the preloading mechanism is provided within the spring cuf f . In an even further embodiment thereof , the preloading mechanism comprises a preloading pressure chamber, a pretensioner and a preloading plate, wherein the preloading pressure chamber is configured for holding a fluid to generate a preloading force applied to the pretensioner, which preloading force is applied to the absorbing spring by means of the preloading plate, wherein the preloading pressure chamber is in fluid communication with the height adj usting mechanism. Preferably the preloading pressure chamber is in fluid communication with the first upper chamber portion . In case a longer, and thus generally heavier, person is placed onto the seat, the longer person usually adj ust the height of the seat to a higher position . When the first closed piston moves upwards , the volume of the first lower chamber portion increases and the volume of the first upper chamber portion decreases . Due to the decreasing volume of the first upper chamber portion, fluid therein is forced towards the preloading pressure chamber thereby increasing the pressure within the preloading pressure chamber . The increased pressure within the preloading pressure chamber results in an increasing volume thereof , such that the preloading pressure chamber expands and the pretensioner exerts an increased preloading force to the absorbing spring . When a shorter, and thus generally lighter, person is placed onto the seat, the opposite may happen and a smaller preload force will be applied to the absorbing spring . An advantage of this embodiment is that the preload force of the absorbing spring is adj usted in dependence of the length and thereby the weight of the person sitting on the seat .

In an embodiment , the shock absorber comprises a helper spring arranged within the spring cuff and around a part of the absorbing spring and the absorbing cylinder . Preferably, the preloading mechanism is configured to preload the helper spring too . The helper spring may be used for helping in adj usting the height by means of the height adj usting mechanism, as the helper spring keeps exerting a small preload onto the preloading mechanism . This seems to be advantageous , in particular, for relatively light persons .

In an embodiment, the absorbing piston rod passes through a sealing end of the absorbing cylinder, wherein the sealing end comprises a cylinder seal with a receiving groove at the side facing the absorbing chamber, and a rubber end stop arranged within the receiving groove, wherein the rubber end stop proj ects from the surface of the cylinder seal into the absorbing chamber . An advantage of this embodiment is that the rubber end stop prevents the absorbing valve from colliding to the cylinder seal when the absorbing piston rod is suddenly moved out of the absorbing chamber and into the position in which the absorbing valve abuts against the sealing end of the absorbing cylinder .

In an embodiment , the shock absorber comprises a further connector arranged at the first piston rod end and configured for being connected to an external obj ect, and the connector arranged at the height adj usting mechanism.

According to a second aspect , the invention provides an assembly of a seat construction and a shock absorber connected thereto, wherein the seat construction has a fixed side configured to be mounted to an external obj ection, and a moving side at which a seat is provided, wherein the shock absorber is provided between the fixed side and the moving side and is a shock absorber according to the first aspect of the invention .

The various aspects and features described and shown in the specification can be applied, individually, wherever possible . These individual aspects , in particular the aspects and features described in the attached dependent claims , can be made subj ect of divisional patent applications .

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis of an exemplary embodiment shown in the attached drawings , in which :

Figure 1 shows an isometric view of a shock absorber according to an embodiment of the invention; and

Figure 2 shows a cross-sectional view of the shock absorber of figure 1 .

DETAILED DESCRIPTION OF THE INVENTION

An isometric view of a shock absorber 1 according to an embodiment of the invention is shown in figure 1 . The shock absorber 1 , for example, may be used for operatively arranging a seat construction, for example, to a vessel . During use , the shock absorber 1 may absorb shocks , caused by an uneven surface, for examples bumps or waves on/in which the vessel moves . As a result , a person sitting on the seat will have a more ergonomic seating position and may experience less or reduced shocks , or is even prevented from being thrown of the seat due to the uneven surface .

As schematically shown in figures 1 and 2 , the shock absorber 1 comprises an absorbing cylinder 2 having a first cylinder end and a second cylinder end, at which a first chamber closure 15 is provided, and in which an absorbing chamber 3 , in particular a cylindrical absorbing chamber, is defined . The absorbing chamber 3 is configured for holding an absorbing fluid 4 , such as an absorbing oil .

The shock absorber 1 further has an absorbing piston rod 5 with a first piston rod end 6 and a second piston rod end 7 , opposite to the first piston rod end 6 in the longitudinal direction of the absorbing piston rod 5 . The absorbing piston rod 5 is arranged partially within the absorbing chamber 3 , wherein the absorbing piston rod 5 extends moveable through a sealing end 8 , i . e . the first cylinder end, of the absorbing cylinder 2 . At the first piston rod end 6, which is located outside the absorbing chamber 3 , the absorbing piston rod 5 is provided with a first connector 9, which is arranged at the first piston rod end 6, wherein the first connector 9 has a first connector eye 10 for connecting the first connector 9 , for example, to a not shown mounting frame of the vessel . At the second piston rod end 7 , which is located within the absorbing chamber 3 , the absorbing piston rod 5 is provided with an absorbing piston 11 , which is arranged at the second piston rod end 7 . The absorbing piston 11 divides the absorbing chamber 3 into an absorbing upper chamber portion 12 and an absorbing lower chamber portion 13 , and is configured for dampening movement of the absorbing piston rod 5. The volume of each of the absorbing upper chamber portion 12 and the absorbing lower chamber portion 13 depends on the position of the absorbing piston 11 within the absorbing chamber 3 , which position depends among others on a load applied to the shock absorber 1 .

The shock absorber 1 further includes a pressure cylinder 20 that is externally located with respect to the absorbing chamber 3 . The pressure cylinder 20 has a cylindrical hollow sleeve 21 with a first closed end 22 , in the figure at the lower end of the cylindrical hollow sleeve 21 , a second closed end 23 , in the figure at the upper end of the cylindrical hollow sleeve 21 , and a pressure chamber 24 defined within the cylindrical sleeve 21 . The pressure chamber 24 is bounded by the inner surface of the cylindrical sleeve 21 and the first and second closed ends 22 , 23 . A separation piston 25 is arranged within the cylindrical sleeve 21 in a moveable manner, thereby dividing the pressure chamber 24 into a pressurizing chamber portion 26 and a pressuri zed chamber portion 27 . Moving the separation piston 25, in the figure, upwards or downwards results in reducing or enlarging the volume of the pressurized chamber portion 27 , respectively . The pressurized chamber portion 27 is configured for holding an absorbing fluid, in particular the same absorbing fluid as the absorbing chamber 3 , and the pressuri zing chamber portion 26 is configured for holding, for example , an inert gas such as nitrogen, wherein contact between the inert gas and the absorbing fluid is prevented by the separation piston 25 .

The pressure cylinder 20 is arranged at, in particular fixed to , the outer side of the absorbing cylinder

2 . The pressure chamber 24 of the pressure cylinder 20 , in particular the pressuri zed chamber portion 27 thereof , is fluidly connected to the absorbing chamber 3 , in particular the absorbing upper chamber portion 12 thereof , such that absorbing fluid may flow from the absorbing chamber 3 to the pressuri zed chamber portion 27 of the pressure chamber 24 within the pressure cylinder 20 . The fluid connection is realized by means of a first connecting channel 28 extending between the pressuri zed chamber portion 27 and the absorbing chamber 3 , in particular the absorbing upper chamber portion 12 . The first connecting channel 28 comprises in series , from the pressurized chamber portion 27 to the absorbing chamber

3 , a first channel portion 29 , a compression chamber 30 and a second channel portion 31 . A compression adj ustment device 32 is arranged within the compression chamber 30 , which compression adj ustment device 32 is arranged for setting the flow of absorbing fluid therethrough during compression of the absorbing fluid within the absorbing chamber 3 .

The pressure chamber 24 of the pressure cylinder 20 and the absorbing chamber 3 of the absorbing cylinder 2 work together in order to control the pressure within the absorbing chamber 3 in dependence of the absorbing piston rod 5 moving further into or out of the absorbing chamber 3 .

As shown in figures 1 and 2 , a spring cuff 35 is arranged around a part of the absorbing cylinder 2 , in particular close to the upper end of the absorbing cylinder 2 . The spring cuff 35 includes a cuff body 36 arranged at the outer surface of the absorbing cylinder 2 and having a first body portion 37 and a second body portion 38 . The first body portion 37 is arranged concentrically around the absorbing cylinder 2 , and the second body portion 38 is arranged concentrically around the first body portion 37 . As shown in figure 2 , the first body portion 37 has a first height and the second body portion 38 has a second height that is smaller than the first height, wherein the lower ends of the first and second body portions 37 , 38 are arranged at substantially the same level . The first body portion 37 defines a first spring cuff chamber 39 with an open bottom, while the second body portion 38 defines a second spring cuff chamber 40 with a closed bottom. As a result, a spring gap 41 is present between the closed bottom of the second spring cuff chamber 40 and the outer surface of the absorbing cylinder 2 . The first and second spring cuff chambers 39, 40 are in open communication with each other, wherein the inner surface of the first spring cuff chamber 39 merges via a diameter step into the inner surface of the second spring cuff chamber 40 .

As shown in figure 2 , a preloading mechanism 45 is arranged within the spring cuff 35, which extends through the first and second spring cuff chambers 39 , 40 . The preloading mechanism 45 is provided with a preloading pressure chamber 46 that is defined in the first spring cuff chamber 39 , in particular at or near the upper end thereof . Additionally, the preloading mechanism 45 has a pretensioner 47 , in particular an annular pretensioner, arranged concentrically around the absorbing cylinder 2 and within the first spring cuf f chamber 39. In particular, the pretensioner 47 is provided below the preloading pressure chamber 46. The pretensioner 47 is provided in a sealing manner between the outer surface of the absorbing cylinder 2 and the inner surface of the first spring cuf f chamber 39 , and is moveable in dependence of a pressure within the preloading pressure chamber 46 , along the absorbing cylinder 2 in a direction parallel to the longitudinal direction of the absorbing cylinder 2 . The preloading mechanism 45 is further provided with an annular preloading plate 48 having an absorbing spring portion 49, located within the first spring cuff chamber 39, and a helper spring portion 50 , located within the second spring cuff chamber 40 , which are connected to each other by a connecting portion 51 . As shown in figure 2 , the absorbing spring and helper spring portions 49, 50 extend substantially transverse to the longitudinal direction of the absorbing cylinder 2 , wherein the absorbing spring portion 49 is located at a higher level than the helper spring portion 50 . The absorbing spring portion 49 , in particular the upper side thereof , is abutting against the pretensioner 47 , and the helper spring portion 50 is provided with an upstanding edge 52 that is facing downwards from the helper spring portion 50 .

An absorbing spring 55 is provided around a part of the absorbing piston rod 5 and a part of the absorbing cylinder 2 and partially within the spring cuf f 35, in particular the first spring cuff chamber 39 thereof , which absorbing spring 55 extends between the first connector 9 and the preloading mechanism 45, in particular the absorbing spring portion 49 thereof . A helper spring 56 is provided around a part of the absorbing cylinder 2 and a part of the absorbing spring 55, and within the spring cuf f 35 , in particular the second spring cuff chamber 40 , wherein the helper spring 56 is locked between the closed bottom of the second spring cuff chamber 40 and the helper spring portion 50 of the preloading mechanism 45.

As shown in figure 2 , the absorbing cylinder 2 comprises a cylinder seal 57 at the sealing end 8 thereof . The cylinder seal 57 allows the absorbing piston rod 5 to pass therethrough in a sealing manner, while the absorbing piston rod 5 may be moved in a direction substantially parallel to the longitudinal direction of the absorbing cylinder 2 . At the side facing towards the absorbing chamber 3 , the cylinder seal 57 has a receiving groove 58 , in particular an annular receiving groove 58 , in which a rubber end stop 59 is received . As clearly shown, the rubber end stop 59 extends beyond the surface of the cylinder seal 57 facing towards the absorbing chamber 3 .

The absorbing piston 11 , as best shown in figure 2 , has not shown fluid channels extending therethrough to allow the absorbing fluid 4 within the absorbing chamber 3 to flow through the absorbing piston 11 .

As shown in figure 2 , the shock absorber 1 is provided with a height adj usting mechanism 70 that, according to this exemplary embodiment, is arranged on top of the absorbing cylinder 2 , i . e . on top of the first chamber closure 15. The height adj usting mechanism 70 has a first adj usting chamber 71 and a second adj usting chamber 72 , located above the first adj usting chamber 71 , defined therein . Each of the first and second adj usting chambers 71 , 72 is configured for holding a fluid, such as an oil . Further, the height adj usting mechanism 70 has a height adj usting rod 73 that extends from the first adj usting chamber 71 , through the second adj usting chamber 72 , to above the second adj usting chamber 72 , such that the height adj usting rod 73 is located partially outside the first and second adj usting chambers 71 , 72 . The height adj usting rod 73 has a first end 74 that is located within the first adj usting chamber 71 , and a second end 75, opposite to the first end 74 in the longitudinal direction of the height adj usting rod 73 , which second end 75 is located outside each of the first and second adj usting chambers 71 , 72 . At the second end 75 of the height adj usting rod 73 , a second connector 76 with a second connector eye 77 is provided .

As shown in figures 1 and 2 , according to this exemplary embodiment , the height adj usting mechanism 70 and the absorbing cylinder 2 are connected to each other, thereby forming as a unitary piece .

The first and second adj usting chambers 71 , 72 are separated from each other by means of a second chamber closure 78 , wherein the first adj usting chamber 71 is located between the first and second chamber closures 15, 78 , and the second adj usting chamber 72 is located between the second chamber closure 78 and a further sealing end 79 at the top side thereof . The height adj usting rod 73 extends through both of the second chamber closure 78 and the further sealing end 79 in a moveable manner, such that the height adj usting rod 73 is moveable in a direction substantially parallel to the longitudinal direction of the shock absorber 1 .

As shown in figure 2 , the height adj usting rod 73 , at the second end 74 thereof , is provided with a first closed piston 80 that is located within the first adj usting chamber 71 . The first closed piston 80 is arranged within the first adj usting chamber 71 in a moveable manner, such that the first closed piston 80 may be moved within the first adj usting chamber 71 in a direction substantially parallel to the longitudinal direction of the shock absorber 1 . The first closed piston 80 divides the first adj usting chamber 71 into a first lower chamber portion 81 and a first upper chamber portion 82 . The inner surface of the first adj usting chamber 71 and the outer surface of the first closed piston 80 are contacting each other in a sealing manner, such that no fluid may flow from the first lower chamber portion 81 to the first upper chamber portion 82 , or vice versa .

The first lower chamber portion 81 is fluidly connected to the first connecting channel 28 , in particular the compression chamber 30 thereof , via a second connecting channel 83 . The second connecting channel 83 debouches into the first lower chamber portion 81 , in particular near the bottom thereof , and into the compression chamber 30 , such that absorbing fluid may flow freely between the pressure chamber 24 and the first lower chamber portion 81 . Furthermore , the first upper chamber portion 82 is fluidly connected to the preloading mechanism 45 , in particular the preloading pressure chamber 46 thereof , via a third connecting channel 84 . The third connecting channel 84 runs outside the first adj usting chamber 71 and debouches into the first upper chamber portion 82 at or near a top side thereof . As a result, fluid may flow freely between the first upper chamber portion 82 and the preloading pressure chamber 46.

As shown in figure 2 , a second closed piston 85 is arranged at the height adj usting rod 73 at a position between the first and second ends 74 , 75 thereof and such that the second closed piston 85 is located within the second adj usting chamber 72 . The second closed piston 85 is arranged within the second adj usting chamber 72 in a moveable manner, such that the second closed piston 85 may be moved, simultaneously with the first closed piston 80 , within the second adj usting chamber 72 in a direction substantially parallel to the longitudinal direction of the shock absorber 1 . The second closed piston 85 divides the second adj usting chamber 72 into a second lower chamber portion 86 and a second upper chamber portion 87 . The inner surface of the second adj usting chamber 72 and the outer surface of the second closed piston 85 are contacting each other in a sealing manner, such that no fluid may flow from the second lower chamber portion 86 to the second upper chamber portion 87 , or vi ce versa .

The second lower chamber portion 86 and the second upper chamber portion 87 are fluidly connected to each other by means of a fourth connecting channel 88 . The fourth connecting channel 88 debouches into the second lower chamber portion 86 near the bottom side thereof , and into the second upper chamber portion 87 at the top side thereof . The fourth connecting channel 88 may allow fluid to flow from the second lower chamber portion 86 to the second upper chamber portion 87 , or vice versa . Additionally, a fifth connecting channel 89 is provided between the fourth connecting channel 88 and the first connecting channel 28 , in particular the compression chamber 30 thereof , which fifth connecting channel 89 debouches into the fourth connecting channel 88 and the compression chamber 30 . The fi fth connecting channel 89 has a channel valve 60 arranged therein and is provided for allowing fluid to flow from the second adj usting chamber 72 to the pressure chamber 24 , when the temperature , and thereby the volume , of the fluid within the second adj usting chamber 72 increases .

An operating valve 90 is provided within the fourth connecting channel 88 , which operating valve 90 is configured for allowing or blocking a flow of fluid from the second lower chamber portion 86 to the second upper chamber portion 87 , or vice versa . The operating valve 90 has an elongated valve rod 91 that extends partially into the fourth connecting channel 88 and into the exterior via a valve channel 92 provided in the wall of the second adj usting chamber 72 and debouching into the fourth connecting channel 88 and externally . The elongated valve rod 91 is configured for being moved between a blocking position, in which a flow of fluid between the second lower chamber portion 86 and the second upper chamber portion 87 is blocked, and an open position, in which a flow of fluid between the second lower chamber portion 86 and the second upper chamber portion 87 is allowed . The exterior end 93 of the elongated valve rod 91 located outside the valve channel 92 is semi-dome shaped, wherein a biasing spring 94 is provided between the exterior end 93 and the outer surface of the wall of the second adj usting chamber 72 .

As shown in figures 1 and 2 , a height operating lever 95 is provided at the outer surface of the height adj usting mechanism 70 , wherein the height operating lever 95 is operationally connected to the elongated valve rod 91 , in particular the exterior end 93 thereof . The height operating lever 95 is pivotable connected to the exterior of the height adj usting mechanism 70 and is configured for being pivoted between a blocking position and an open position to move the valve rod 91 between the blocking position and the open position . Due to the biasing spring 94 , the height operating lever 95 and the elongated valve rod 91 are pulled into the blocking position by default . Additionally, a limiting rod 96 is provided, which extends through the height operating lever 95 and into the wall of the second adj usting chamber 72 in such manner that pivoting of the height operating lever 95 is limited . As a result , pivoting of the height operating lever 95 only results in moving the valve rod 91 between the blocking position and the open position .

The shock absorber 1 as shown in figures 1-2 , for example, may be used in combination with a seat construction, for example, on a vessel , such that the shock absorber prevents a shock absorbed by the vessel from being passed on to the seat of the seat construction by absorbing the shock . As a result , a person sitting on the respective seat is prevented from encountering numerous shocks during use of the vessel .

The height of the seat that is connected to the second connector 76 of the shock absorber 1 with respect to the vessel that is connected to the first connector 9 of the shock absorber 1 may be adj usted under influence of the weight of a person sitting on the seat, as elucidated below .

The shock absorber 1 as shown in the figures 1-2 , in particular the height adj usting rod 73 with the second connector 76, is at its highest possible position . This may be understood as that a long person and thus a relatively heavy person is sitting on the seat . Alternatively, the highest possible position may be the position into which the connector 76 moves when nobody is sitting on the seat and the operating valve 90 is in the open position . When the long person is replaced by a shorter, and usually lighter, person, the position of the seat may be too high for the shorter person . For example , the shorter person may not be able to touch the floor of the vessel with his feet . Therefore , the shorter person is expected to lower the height of the seat .

When the person sitting on the seat pivots the height operating lever 95 such that the operating valve 90 , in particular the valve rod 91 thereof , is moved from the blocking position to the open position, fluid may flow from the second lower chamber portion 86 to the second upper chamber portion 87 , or vice versa . Due to the person sitting on the seat , thereby applying a force onto the second connector 76 , and the operating valve 90 being in the open position, the first closed piston 80 moves downwards within the first adj usting chamber 71 while the second closed piston 85 moves downwards within the second adj usting chamber 72 under influence of the weight of the person sitting on the seat . This results in lowering of the second connector 76. When the height of the seat is to the likings of the person thereon, the height operating lever 95 is released, such that the biasing spring 94 pivots the height operating lever 95 back into the blocking position thereof such that the operating valve 90 is moved into the blocking position thereof . In the blocking position of the operating valve 90 , no fluid flow is possible between the second lower chamber portion 86 and the second upper chamber portion 87 , thereby maintaining the position of the second closed piston 85 within the second adj usting chamber 72 and thus the height of the second connector 76 .

Due to moving the first closed piston 80 downwards within the first adj usting chamber 71 , the volume of the first upper chamber portion 82 increases . Due to the increasing volume of the first upper chamber portion 82 , fluid is drawn from the preloading pressure chamber 46 into the first upper chamber portion 82 . This results in less pressure being applied to the pretensioner 47 , which moves upwards , together with the preloading plate , within the preloading pressure chamber 46 . Due to the upwards moving pretensioner 47 , the preloading force applied to the absorbing spring 55 is reduced . This results in lowering the preload force applied to the absorbing spring 55 of the shock absorber 1 . Therefore , the shock absorber 1 enables a person to adj ust the height of the seat in dependence of his length, while the preload force applied to the absorbing spring 55 is adj usted simultaneously in dependence of his length and, therefore, in dependence of his weight .

When a person is replaced by a longer person with a higher weight , the opposite may happen wherein moving the seat upwards may be done without a person sitting on the seat . It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention . From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the scope of the present invention .

List of reference numbers

1 => shock absorber

2 => absorbing cylinder

3 => absorbing chamber

4 => absorbing fluid

5 => absorbing piston rod

6 => first piston rod end

7 => second piston rod end

8 => sealing end

9 => first connector

10 => first connector eye

11 => absorbing piston

12 => absorbing upper chamber portion

13 => absorbing lower chamber portion

15 => first chamber closure

20 => pressure cylinder

21 => cylindrical sleeve

22 => first closed end

23 => second closed end

24 => pressure chamber

25 => separation piston

26 => pressuri zing chamber portion

27 => pressuri zed chamber portion

28 => first connecting channel

29 => first channel portion

30 => compression chamber

31 => second channel portion

32 => compression adj ustment device

35 => spring cuf f

36 => cuff body

37 => first body portion

38 => second body portion

39 => first spring cuf f chamber

40 => second spring cuff chamber

41 => spring gap

45 => preloading mechanism => preloading pressure chamber

=> pretensioner

=> preloading plate

=> absorbing spring portion

=> helper spring portion

=> connecting portion

=> upstanding edge

=> absorbing spring

=> helper spring

=> cylinder seal

=> receiving groove

=> rubber end stop

=> channel valve

=> height adj usting mechanism

=> first adj usting chamber

=> second adj usting chamber

=> height adj usting rod

=> first end

=> second end

=> second connector

=> second connector eye

=> second chamber closure

=> further sealing end

=> first closed piston

=> first lower chamber portion

=> first upper chamber portion

=> second connecting channel

=> third connecting channel

=> second closed piston

=> second lower chamber portion

=> second upper chamber portion

=> fourth connecting channel

=> fi fth connecting channel

=> operating valve

=> elongated valve rod

=> valve channel

=> exterior end => biasing spring => height operating lever => limiting rod