CLAIMS

1.

A pistonchamber combination comprising an elongate chamber (162,186,231) which is bounded by an inner chamber wall (156,185,238) and comprising an elastically deformable piston comprising a container (208,208', 217,217', 228,228', 258,258', 450,450') in said chamber to be sealingly movable relative to said chamber at least between first and second longitudinal positions of said chamber, said chamber having crosssections of different crosssectional areas at the first and second longitudinal positions of said chamber and at least substantially continuously different cross sectional areas at intermediate longitudinal positions between the first and second longitudinal positions thereof, the crosssectional area at the first longitudinal position being larger than the crosssectional area at the second longitudinal position, said piston including a piston body and sealing means supported by the piston body for sealing on said inner chamber wall, wherein said piston body being designed to adapt itself and said sealing means to said different cross sectional areas of said chamber during the relative movements of said piston from the second longitudinal position through said intermediate longitudinal positions to the first longitudinal position of said chamber.

2.	A combination according to claim 1, wherein the crosssectional area of said chamber at the second longitudinal position thereof is between 95% and 15% of the cross sectional area of said chamber at the first longitudinal position thereof.

3.	A combination according to claim 1, wherein the crosssectional area of said chamber at the second longitudinal position thereof is 9570% of the crosssectional area of said chamber at the first longitudinal position thereof.

4.	A combination according to claim 1, wherein the crosssectional area of said chamber at the second longitudinal position thereof is approximately 50% of the cross sectional area of said chamber at the first longitudinal position thereof.

5.	A combination according to any of claims 1 to 4, wherein the piston ( 208,208', 217,217', 228,228', 258,258', 450,450') comprising a deformable material (205,206).

6.	A combination according to claim 5, wherein the deformable material (205,206) is a fluid or a mixture of fluids, such as water, steam and/or gas, or a foam.

7.

A combination according to claim 5 or 6, wherein, in a crosssection through the longitudinal direction, the container, when being positioned at the first longitudinal position of the chamber (162,186,231), has a first shape which is different from a second shape of the container when being positioned at the second longitudinal position of said chamber.

8.	A combination according to claim 7, wherein at least part of the deformable material (206) is compressible and wherein the first shape has an area being larger than an area of the second shape.

9.	A combination according to claim 7, wherein the deformable material (206) is at least substantially incompressible.

10.	A combination according to claim 5 or 6, wherein the container is inflatable, to a certain predetermined pressure value.

11.	A combination according to claim 10, wherein the pressure remains constant during the stroke.

12.	A combination according to any of claims 5 to 11, wherein the piston ( 208,208', 217,217', 228,228', 258,258', 450,450') comprises an enclosed space (210,243) communicating with the deformable container, the enclosed space (210,243) having a variable volume.

13.	A combination according to claim 12, wherein the volume is adjustable.

14.	A combination according to claim 12, wherein the first enclosed space (210) comprises a springbiased pressure tuning piston (126).

15.	A combination according to any of claims 12 to 14, further comprising means (126, wall of 195,246,248,249,273,274) for defining the volume of the first enclosed space (210) so that the pressure of fluid in the first enclosed space (210) relates to the pressure in the second enclosed space (243).

16.	A combination according to claim 15, wherein the the defining means (126,194, 195,246,248,249,273,274) are adapted to define the pressure in the first enclosed space (210) during the stroke.

17.	A combination according to claim 15, wherein the defining means (126, wall of 195,246,248,249,273,274) are adapted to define the pressure in the first enclosed space (210) at least substantially constant during the stroke.

18.	A combination according to claim 14, wherein the springbiased pressure tuning piston (126) is a check valve (242) through which fluid of an external pressure source can flow into the first enclosed space (210).

19.	A combination according to claim 18, wherein the fluid from an external pressure source can enter the second enclosed space (243) through an inflation valve, preferably a valve with a core pin (245) biased by a spring, such as a Schrader valve (241) from an external pressure source.

20.	A combination according to claim 1, wherein the piston (248) is communicating with at least one valve (260).

21.	A combination according to claim 20, wherein the piston comprises a pressure source.

22.	A combination according to claim 20, wherein the valve is an inflation valve, preferably a valve with a core pin (245) biased by a spring, such as a Schrader valve (260).

23.	A combination according to claim 20, wherein the valve is a check valve.

24.	A combination according to claim 1, wherein the foot (262) of the chamber (162,1 86,231) comprises at least one valve (263,269).

25.	A combination according to claim 24, wherein the outlet valve is inflation valve preferably a valve with a core pin (245) biased by a spring, such as a Schrader valve (263), said core pin is moving towards the chamber (162,186,231) when closing the valve.

26.	A combination according to claim 22 20 or 25 23, wherein the core pin (245) of the valve (260,263) is connected to a valve actuator (261) or an activating pin.

27.

A combination according to claim 26 24, wherein the valve actuator for operating with valves having a springforce operated valve core pin, comprising a housing to be connected to a pressure medium source; within the housing a coupling section for receiving the valve to be actuated, a cylinder circumferentially surrounded by a cylinder wall of a predetermined cylinder wall diameter and having a first cylinder end and a second cylinder end which is farther away from the coupling section than said first cylinder end and is connected to the housing for receiving pressure medium from said pressure source, a piston which is movably located in the cylinder and fixedly coupled to an activating pin for engaging with the springforce operated valve core pin of the valve received in the coupling section, and a conducting channel between said second cylinder end and said coupling section for conducting pressure medium from said second cylinder end to the coupling section when the piston is moved into a first piston position in which the piston is at a first predetermined distance from said first cylinder end, said conduction of pressure medium between said second cylinder end and the coupling section being inhibited when the piston is moved into a second piston position in which the piston is at a second predermined distance from said first cylinder end which second distance being larger than said first distance, wherein the conducting channel is arranged in said cylinder wall and has a channel portion which opens into the cylinder at a cylinder wall portion having said predetermined cylinder wall diameter, and the piston comprises a piston ring with a sealing edge which sealingly fits with said cylinder wall portion, said sealing edge of the piston ring being located between said channel portion and said second cylinder end in said second piston position, thereby inhibiting said conduction of the pressure medium from said second cylinder end into the channel in said second piston position, and being located between said channel portion and said first cylinder end in said first piston position, thereby opening the channel to said second cylinder end in said first piston position.

28.	A combination according to claim 20, wherein the piston comprising means to obtain a predetermined pressure level.

29.	A combination according to claim 20 or 28, wherein the valve is a release valve.

30.	A combination according to claim 28, wherein a springforce operated cap (312) which closes the channel (286) above the valve actuator (261) when the pressure comes above a certain predetermined pressure value.

31.

A combination according to claim 28, wherein a channel can be opened or closed, the channel connects the chamber (186) and the space (305,306,307) between the valve actuator (261) and the core pin (245), a piston (292) is movable between an opening position (294) and a closing position (295) of said channel, and the movement of the piston (292) is controlled by an actuator (363) which is steered as a result of a measurement of the pressure in the piston (208,208', 217,217', 228,228', 238,238', 450,450').

32.	A combination according to claim 25, wherein a channel (297) can be opened or closed, which connects the chamber (186) and the space (305,306,307) between the valve actuator (261) and the core pin (245).

33.	A combination according to claim 25 or 32, wherein a piston (292) is movable between an opening position (294) and a closing position (295) of said channel.

34.	A combination according to claim 33, wherein the piston (292) is operated by a operator controlled pedal (265), which is turning around an axle (264) from a inactive position (277) to an activated position (277') and vice versa.

35.	A combination according to claim 33, wherein the piston (292) is controlled by an actuator (366) which is steered as a result of a measurement of the pressure in the piston (208,208', 217,217', 228,228', 238,238', 450,450').

36.	A combination according to any of claims 12 to 14, further comprising means (321,322,323,324) for defining the volume of the enclosed space (325) so that the pressure of fluid in the enclosed space (210) relates to the pressure acting on the piston (208,208') during the stroke.

37.

A combination according to any of claims 6 to 17, wherein the foam or fluid is adapted to provide, within the container, a pressure higher than the highest pressure of the surrounding atmosphere during translation of the piston (148,149) from the second longitudi nal position of the chamber (216) to the first longitudinal position thereof or vice versa.

38.	A combination according to any of claims 5 to 17, wherein the container comprises an elastically deformable material comprising reinforcement means.

39.	A combination according to claim 39, wherein the reinforcement windings having a braid angle which is different from 54°44'.

40.	A combination according to claim 38 or 39, wherein the reinforcement means comprise a textile reinforcement.

41.	A combination according to claim 38 or 39, wherein the reinforcement means comprise fibres.

42.	A combination according to claim 42, wherein the fibers are arrangend as to the Trellis Effect.

43.	A combination according to claim 38, wherein the reinforcement means comprises a flexable material positioned in the container, comprising a plurality of at least substantially elastic support members rotatably fastened to a common member, the common members connected to the skin of the container.

44.	A combination according to claim 43, wherein said members and/or the common member are inflatable.

45.

A pistonchamber combination comprising an elongate chamber (231) bounded by an inner chamber wall and comprising a piston in the chamber to be sealingly movable in the chamber, the piston (230) being movable in the chamber (231) at least from a first longitudinal position thereof to a second longitudinal position thereof, the chamber (231) comprising an elastically deformable inner wall (238) along at least part of the length of the chamber wall between the first and second longitudinal positions, the chamber (231) having, at the first longitudinal position thereof when the piston (230) is positioned at that position, a first crosssectional area, which is larger than a second crosssectional area at the second longitudinal position of the chamber (231) when the piston (230) is positioned at that position, the change in crosssections of the chamber (231) being at least substantially continuous between the first and second longitudinal positions when the piston (230) is moved between the first and second longitudinal positions.

46.	A combination according to claim 45, wherein the piston (230) is made of an at least substantially incompressible material.

47.	A combination according to claim 45 or 46, wherein the piston (230) has, in a cross section along the longitudinal axis, a shape tapering in a direction from the first longitudinal position of the chamber (231) to the second longitudinal position thereof.

48.	A combination according to claim 47, wherein the angle () between the wall (238) and the central axis (236) of the cylinder (231) is at least smaller than the angle (u) between the wall of the taper of the piston (230) and the central axis (236) of the chamber (231).

49.	A combination according to any of claims 45 to 48, wherein the chamber (231) comprises: an outer supporting structure (234) enclosing the inner wall (238) and a fluid (232,233) held by a space defined by the outer supporting structure (234) and the inner wall (238).

50.	A combination according to claim 49, wherein the space defined by the outer structure (234) and the inner wall (238) is inflatable.

51.	A combination according to claim 45, wherein the piston (450') comprises an elastically deformable container comprising a deformable material and designed according to claims 7 to 17.

52.

A combination according to any of claims 38 to 47, wherein the foam or fluid is adapted to provide, within the container, a pressure higher than the highest pressure of the surrounding atmosphere during translation of the piston (148,149) from the second longitudi nal position of the chamber (216) to the first longitudinal position thereof or vice versa.

53.	A pump for pumping a fluid, the pump comprising: a combination according to any of the preceeding claims, means for engaging the piston from a position outside the chamber, a fluid entrance connected to the chamber and comprising a valve means, and a fluid exit connected to the chamber.

54.	A pump according to claim 53, wherein the engaging means have an outer position where the piston is at the first longitudinal position of the chamber, and an inner position where the piston is at the second longitudinal position of the chamber.

55.	A pump according to claim 53, wherein the engaging means have an outer position where the piston is at the second longitudinal position of the chamber, and an inner position where the piston is at the first longitudinal position of the chamber.

56.

A shock absorber comprising: a combination according to any of claims 1 to 53, means for engaging the piston from a position outside the chamber, wherein the engaging means have an outer position where the piston is at the first longitudinal position of the chamber, and an inner position where the piston is at the second longitudinal position.

57.	A shock absorber according to claim 56, further comprising a fluid entrance connec ted to the chamber and comprising a valve means.

58.	A shock absorber according to claim 56 or 57, further comprising a fluid exit connected to the chamber and comprising a valve means.

59.	A shock absorber according to any of claims 56 to 58, wherein the chamber and the piston form an at least substantially sealed cavity comprising a fluid, the fluid being compressed when the piston moves from the first to the second longitudinal positions of the chamber.

60.	A shock absorber according to any of claims 56 to 59, further comprising means for biasing the piston toward the first longitudinal position of the chamber.

61.	An actuator comprising: a combination according to any of claims 1 to 53, means for engaging the piston from a position outside the chamber, means for introducing fluid into the chamber in order to displace the piston between the first and the second longitudinal positions of the chamber.

62.	An actuator according to claim 61, further comprising a fluid entrance connected to the chamber and comprising a valve means.

63.	An actuator according to claim 61 or 62, further comprising a fluid exit connected to the chamber and comprising a valve means.

64.	An actuator according to any of claims 61 to 63, further comprising means for biasing the piston toward the first or second longitudinal position of the chamber.

65.	An actuator according to any of claims 61 to 64, wherein the introducing means comprise means for introducing pressurised fluid into the chamber.

66.	An actuator according to any of claims 61 to 64, wherein the introducing means are adapted to introduce a combustible fluid, such as gasoline or diesel, into the chamber, and wherein the actuator further comprises means for combusting the combustible fluid.

67.

An actuator according to any of claims 61 to 64, further comprising a crank adapted to translate the translation of the piston into a rotation of the crank. AMENDED CLAIMS [received by the International Bureau on 03 September 2002 (03.09.02); original claims 1,5,16,26,27,45 amended; remaining claims unchanged] 1. A pistonchamber combination comprising an elongate chamber (162,186,231) which is bounded by an inner chamber wall (156,185,238) and comprising a piston in said chamber to be sealingly movable relative to said chamber at least between first and second longitudinal positions of said chamber, said chamber having crosssections of different crosssectional areas and different circumferential lengths at the first and second longitudinal positions of said chamber and at least substantially continuously different crosssectional areas and different circumferential length at intermediate longitudinal positions between the first and second longitudinal positions thereof, the crosssectional area at the first longitudinal position being larger than the crosssectional area at the second longitudinal position, said piston comprising an inflatable container (208, 208', 217, 217', 228,228', 258, 258', 450, 450') having an elasfcaUy deformable container wall for sealing contact on the inner chamber wall, said container being elastically deformable and being inflatable to provide for different crosssectional areas and circumferential lengths of the piston, wherein for adaption to said different crosssectional areas and different circumferential lengths of said chamber during the relative movements of said piston between the first and second longitudinal positions through said intermediate longitudinal positions of said chamber, the piston being produced to have a productionsize of the container in which the container wall has a stressfree and undeformed state, wherein the container (208,208', 217,217', 228,228', 258,258', 450,450') is made to be elastically expandable and to have its circumferential length in the stressfree and undeformed state of its production size approximately the circumferential length of the inner chamber wall of the container at said second longitudinal position.

68.	2 A combination according to claim 1, wherein the crosssectional area of said chamber at the second longitudinal position thereof is between 95% and 15% of the crosssectional area of said chamber at the first longitudinal position thereof.

69.	3 A combination according to claim 1, wherein the crosssectional area of said chamber at the second longitudinal position thereof is 9570% of the crosssectional area of said chamber at the first longitudinal position thereof.

70.	4 A combination according to claim 1, wherein the crosssectional area of said chamber at the second longitudinal position thereof is approximately 50% of the crosssectional area of said chamber at the first longitudinal position thereof.

71.	5 A combination according to any of claims 1 to 4, wherein the container (208, 208', 217,217', 228,228', 258,258', 450,450') contains a deformable material (205, 206).

72.	6 A combination according to claim 5, wherein the deformable material (205, 206) is a fluid or a mixture of fluids, such as water, steam and/or gas, or a foam.

73.

7 A combination according to claim 5 or 6, wherein, in a crosssection through the longitudinal direction, the container, when being positioned at the first longitudinal position of the chamber (162,186,231), has a first shape which is different from a second shape of the container when being positioned at the second longitudinal position of said chamber.

74.	8 A combination according to claim 7, wherein at least part of the deformable material (206) is compressible and wherein the first shape has an area being larger than an area of the second shape.

75.	9 A combination according to claim 7, wherein the deformable material (206) is at least substantially incompressible.

76.	10 A combination according to claim 5 or 6, wherein the container is inflatable, to a certain predetermined pressure value.

77.	11 A combination according to claim 10, wherein the pressure remains constant during the stroke.

78.	12 A combination according to any of claims 5 to 11, wherein the piston {208, 208', 217,217', 228, 228', 258,258', 450,450') comprises an enclosed space (210,243) communicating with the deformable container, the enclosed space (210, 243) having a variable volume.

79.	13 A combination according to claim 12, wherein the volume is adjustable.

80.	14 A combination according to claim 12, wherein the first enclosed space (210) comprises a springbiased pressure tuning piston (126).

81.

15 A combination according to any of claims 12 to 14, further comprising means (126, wall of 195, 246,248,249,273, 274) for defining the volume of the first enclosed space (210) so that the pressure of fluid in the first enclosed space (210) relates to the pressure in the second enclosed space (243).

82.	16 A combination according to claim 15, wherein the defining means (126,194, 195,246,248,249,273, 274) are adapted to define the pressure in the first enclosed space (210) during the stroke.

83.	17 A combination according to claim 15, wherein the defining means (126, wall of 195,246,248,249,273,274) are adapted to define the pressure in the first enclosed space (210) at least substantially constant during the stroke.

84.	18 A combination according to claim 14, wherein the springbiased pressure tuning piston (126) is a check valve (242) through which fluid of an external pressure source can flow into the first enclosed space (210).

85.	19 A combination according to claim 18, wherein the fluid from an external pressure source can enter the second enclosed space (243) through an inflation valve, preferably a valve with a core pin (245) biased by a spring, such as a Schrader valve (241) from an external pressure source.

86.	20 A combination according to claim 1, wherein the piston (248) is communicating with at least one valve (260).

87.	21 A combination according to claim 20, wherein the piston comprises a pressure source.

88.	22 A combination according to claim 20, wherein the valve is an inflation valve, preferably a valve with a core pin (245) biased by a spring, such as a Schrader valve (260).

89.	23 A combination according to claim 20, wherein the valve is a check valve.

90.	24 A combination according to claim 1, wherein the foot (262) of the chamber (162,186,231) comprises at least one valve (263,269).

91.	25 A combination according to claim 24, wherein the outlet valve is inflation valve preferably a valve with a core pin (245) biased by a spring, such as a Schrader valve (263), said core pin is moving towards the chamber (162,186,231) when closing the valve.

92.	26 A combination according to claim 22 or 25, wherein the core pin (245) of the valve (260,263) is connected to a valve actuator (261) or an activating pin.

93.

27 A combination according to claim 26, wherein the valve actuator for operating with valves having a springforce operated valve core pin, comprising a housing to be connected to a pressure medium source ; within the housing a coupling section for receiving the valve to be actuated, a cylinder circumferentially surrounded by a cylinder wall of a predetermined cylinder wall diameter and having a first cylinder end and a second cylinder end which is farther away from the coupling section than said first cylinder end and is connected to the housing for receiving pressure medium from said pressure source, a piston which is movably located in the cylinder and fixedly coupled to an activating pin for engaging with the springforce operated valve core pin of the valve received in the coupling section, and a conducting channel between said second cylinder end and said coupling section for conducting pressure medium from said second cylinder end to the coupling section when the piston is moved into a first piston position in which the piston is at a first predetermined distance from said first cylinder end, said conduction of pressure medium between said second cylinder end and the coupling section being inhibited when the piston is moved into a second piston position in which the piston is at a second predermined distance from said first cylinder end which second distance being larger than said first distance, wherein the conducting channel is arranged in said cylinder wall and has a channel portion which opens into the cylinder at a cylinder wall portion having said predetermined cylinder wall diameter, and the piston comprises a piston ring with a sealing edge which sealingly fits with said cylinder wall portion, said sealing edge of the piston ring being located between said channel portion and said second cylinder end in said second piston position, thereby inhibiting said conduction of the pressure medium from said second cylinder end into the channel in said second piston position, and being located between said channel portion and said first cylinder end in said first piston position, thereby opening the channel to said second cylinder end in said first piston position.

94.	28 A combination according to claim 20, wherein the piston comprising means to obtain a predetermined pressure level.

95.	29 A combination according to claim 20 or 28, wherein the valve is a release valve.

96.	30 A combination according to claim 28, wherein a springforce operated cap (312) which closes the channel (286) above the valve actuator (261) when the pressure comes above a certain predetermined pressure value.

97.

31 A combination according to claim 28, wherein a channel can be opened or closed, the channel connects the chamber (186) and the space (305,306,307) between the valve actuator (261) and the core pin (245), a piston (292) is movable between an opening position (294) and a closing position (295) of said channel, and the movement of the piston (292) is controlled by an actuator (363) which is steered as a result of a measurement of the pressure in the piston (208, 208', 217,217', 228, 28,238,238', 450,450').

98.	32 A combination according to claim 25, wherein a channel (297) can be opened or closed, which connects the chamber (186) and the space (305,306,307) between the valve actuator (261) and the core pin (245).

99.	33 A combination according to claim 25 or 32, wherein a piston (292) is movable between an opening position (294) and a closing position (295) of said channel.

100.	34 A combination according to claim 33, wherein the piston (292) is operated by a operator controlled pedal (265), which is turning around an axle (264) from a inactive position (277) to an activated position (277') and vice versa.

101.	35 A combination according to claim 33, wherein the piston (292) is controlled by an actuator (366) which is steered as a result of a measurement of the pressure in the piston (208, 208', 217,217', 228, 228', 238,238', 450,450').

102.	36 A combination according to any of claims 12 to 14, further comprising means (321,322, 323,324) for defining the volume of the enclosed space (325) so that the pressure of fluid in the enclosed space (210) relates to the pressure acting on the piston (208, 208') during the stroke.

103.

37 A combination according to any of claims 6 to 17, wherein the foam or fluid is adapted to provide, within the container, a pressure higher than the highest pressure of the surrounding atmosphere during translation of the piston (148,149) from the second longitudi nal position of the chamber (216) to the first longitudinal position thereof or vice versa.

104.	38 A combination according to any of claims 5 to 17, wherein the container comprises an elastically deformable material comprising reinforcement means.

105.	39 A combination according to claim 39, wherein the reinforcement windings having a braid angle which is different from 54°44'.

106.	40 A combination according to claim 38 or 39, wherein the reinforcement means comprise a textile reinforcement.

107.	41 A combination according to claim 38 or 39, wherein the reinforcement means comprise fibres.

108.	42 A combination according to claim 42, wherein the fibers are arrangend as to the Trellis Effect.

109.

43 A combination according to claim 38, wherein the reinforcement means comprises a flexable material positioned in the container, comprising a plurality of at least substantially elastic support members rotatably fastened to a common member, the common members connected to the skin of the container.

110.	44 A combination according to claim 43, wherein said members and/or the common member are inflatable.

111.

45 A pistonchamber combination comprising an elongate chamber (231) bounded by an inner chamber wall and comprising a piston in the chamber to be sealingly movable in the chamber, the piston (230) being movable in the chamber (231) at least from a first longitudinal position thereof to a second longitudinal position thereof, the chamber (231) comprising an elastically deformable inner wall (238) along at least part of the length of the chamber wall between the first and second longitudinal positions, the chamber (231) having, at the first longitudinal position thereof when the piston (230) is positioned at that position, a first crosssectional area, which is larger than a second crosssectional area at the second longitudinal position of the chamber (231) when the piston (230) is positioned at that position, the change in crosssections of the chamber (231) being at least substantially continuous between the first and second longitudinal positions when the piston (230) is moved between the first and second longitudinal positions the piston including an elastically expandable container having changeable geometrical shapes which adapt to each other during the piston stroke thereby enabling a continuous sealing, and the piston having its production size when positioned at the second longitudinal position of the chamber.

112.	46 A combination according to claim 45, wherein the piston (230) is made of an at least substantially incompressible material.

113.	47 A combination according to claim 45 or 46, wherein the piston (230) has, in a cross section along the longitudinal axis, a shape tapering in a direction from the first longitudinal position of the chamber (231) to the second longitudinal position thereof.

114.	48 A combination according to claim 47, wherein the angle (i) between the wall (238) and the central axis (236) of the cylinder (231) is at least smaller than the angle (o) between the wall of the taper of the piston (230) and the central axis (236) of the chamber (231).

115.	49 A combination according to any of claims 45 to 48, wherein the chamber (231) comprises: an outer supporting structure (234) enclosing the inner wall (238) and a fluid (232,233) held by a space defined by the outer supporting structure (234) and the inner wall (238).

116.	50 A combination according to claim 49, wherein the space defined by the outer structure (234) and the inner wall (238) is inflatable.

117.	51 A combination according to claim 45, wherein the piston (450') comprises an elastically deformable container comprising a deformable material and designed according to claims 7 to 17.

118.

52 A combination according to any of claims 38 to 47, wherein the foam or fluid is adapted to provide, within the container, a pressure higher than the highest pressure of the surrounding atmosphere during translation of the piston (148, 149) from the second longitudi nal position of the chamber (216) to the first longitudinal position thereof or vice versa.

119.	53 A pump for pumping a fluid, the pump comprising: a combination according to any of the preceeding claims, means for engaging the piston from a position outside the chamber, a fluid entrance connected to the chamber and comprising a valve means, and a fluid exit connected to the chamber.

120.	54 A pump according to claim 53, wherein the engaging means have an outer position where the piston is at the first longitudinal position of the chamber, and an inner position where the piston is at the second longitudinal position of the chamber.

121.	55 A pump according to claim 53, wherein the engaging means have an outer position where the piston is at the second longitudinal position of the chamber, and an inner position where the piston is at the first longitudinal position of the chamber.

122.

56 A shock absorber comprising: a combination according to any of claims 1 to 53, means for engaging the piston from a position outside the chamber, wherein the engaging means have an outer position where the piston is at the first longitudinal position of the chamber, and an inner position where the piston is at the second longitudinal position.

123.	57 A shock absorber according to claim 56, further comprising a fluid entrance connected to the chamber and comprising a valve means.

124.	58 A shock absorber according to claim 56 or 57, further comprising a fluid exit connected to the chamber and comprising a valve means.

125.	59 A shock absorber according to any of claims 56 to 58, wherein the chamber and the piston form an at least substantially sealed cavity comprising a fluid, the fluid being compressed when the piston moves from the first to the second longitudinal positions of the chamber.

126.	60 A shock absorber according to any of claims 56 to 59, further comprising means for biasing the piston toward the first longitudinal position of the chamber.

127.	61 An actuator comprising : a combination according to any of claims 1 to 53, means for engaging the piston from a position outside the chamber, means for introducing fluid into the chamber in order to displace the piston between the first and the second longitudinal positions of the chamber.

128.	62 An actuator according to claim 61, further comprising a fluid entrance connected to the chamber and comprising a valve means.

129.	63 An actuator according to claim 61 or 62, further comprising a fluid exit connected to the chamber and comprising a valve means.

130.	64 An actuator according to any of claims 61 to 63, further comprising means for biasing the piston toward the first or second longitudinal position of the chamber.

131.	65 An actuator according to any of claims 61 to 64, wherein the introducing means comprise means for introducing pressurised fluid into the chamber.

132.	66 An actuator according to any of claims 61 to 64, wherein the introducing means are adapted to introduce a combustible fluid, such as gasoline or diesel, into the chamber, and wherein the actuator further comprises means for combusting the combustible fluid.

133.

67 An actuator according to any of claims 61 to 64, further comprising a crank adapted to translate the translation of the piston into a rotation of the crank. STATEMENT UNDER ARTICLE 19 (1) The amendments in claims 1 and 45 were made to limit the claims against the references cited in the international Search Report. Neither GB 2070731 A nor GB 2023715 A does show a pistonchamber combination comprising a piston including an elasticallly expandable container. Further, the inflatable containers of the piston of the pistonchamber combinations disclosed in WO 0070227 A1 and in WO 0065235 A1 are shown to have their production sizes in the first longitudinal positions of the chamber where the chamber has its largest crosssection, and the containers seem not disclosed to be elastically expandable. Claims 1,5,16,26,27,45 have been amended.