Combination of a chamber and a piston, a pump, a motor, a shock absorber and a transducer incorporating the combination

Abstract

A combination of a piston and a chamber, wherein the chamber defines an elongate chamber having a longitudinal axis, the chamber having, at a first longitudinal position thereof, a first cross-sectional area thereof and, at a second longitudinal position thereof, a second cross-sectional area, the second cross-sectional area being 95% or less of the first cross-sectional area, the change in cross-section of the chamber being at least substantially continuous between the first and second longitudinal positions, the piston being adapted to adapt itself to the cross-section of the chamber when moving from the first to the second longitudinal position of the chamber. The piston may comprise an umbrella-like support structure or a fiber enforced deformable container comprising a foam or a fluid. The combination may be used in a pump, a linear actuator, a motor, or a shock absorber.

1 . A piston-chamber combination comprising:
 an elongate chamber which is bounded by an inner chamber wall and comprising a piston means in said chamber,   the piston having a seal thereon that is movable relative to said chamber at least between first and second longitudinal positions of said chamber,   said chamber having cross-sections of different cross-sectional areas at the first and second longitudinal positions of said chamber, and at least substantially continuously differing cross-sectional areas at intermediate longitudinal positions between the first and second longitudinal positions thereof, the cross-sectional area at the first longitudinal position being larger than the cross sectional area at the second longitudinal position,   said piston being designed to adapt itself and the seal to different cross-sectional areas of the chamber during the relative movements of the piston from the first longitudinal position through said intermediate longitudinal positions to the second longitudinal position of said chamber,   wherein the cross-sections of the different cross-sectional areas have different cross-sectional shapes, the change in cross-sectional shape of the chamber being continuous between the first and second longitudinal positions of the chamber,   wherein the piston is further designed to adapt itself and the seal to the different cross-sectional shapes, and   wherein a first circumferential length of the cross-sectional shape of the chamber at the first longitudinal position thereof amounts to 80-120% of a second circumferential length of the cross-sectional shape of the chamber at the second longitudinal position thereof.   
     
     
         2 . The piston-chamber combination according to  claim 1 , wherein the cross-sectional shape of the chamber at the first longitudinal position thereof is at least substantially circular, and
 wherein the cross-sectional shape of the chamber at the second longitudinal position thereof has an elongate shape, such as oval, having a first dimension that is at least 2 times a dimension at an angle to the first dimension.   
     
     
         3 . The piston-chamber combination according to  claim 1 , wherein the cross-sectional shape of the chamber at the first longitudinal position thereof is at least substantially circular, and
 wherein the cross-sectional shape of the chamber at the second longitudinal position thereof comprises two or more at least substantially elongate shaped parts.   
     
     
         4 . The piston-chamber combination according to  claim 1 , wherein a first circumferential length of the cross-sectional shape of the chamber at the first longitudinal position thereof amounts to 85-115%, of a second circumferential length of the cross-sectional shape of the chamber at the second longitudinal position thereof. 
     
     
         5 . The piston-chamber combination according to  claim 4 , wherein the first and second circumferential lengths are at least substantially identical. 
     
     
         6 . The piston-chamber combination according to  claim 1 , wherein the cross-sectional area of said chamber at the second longitudinal position thereof is 95% or less of the cross-sectional area of said chamber at the first longitudinal position thereof. 
     
     
         7 . The piston-chamber combination according to  claim 6 , wherein the cross-sectional 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. 
     
     
         8 . The piston-chamber combination according to  claim 6 , wherein the cross-sectional area of said chamber at the second longitudinal position thereof is 95-70% of the cross-sectional area of said chamber at the first longitudinal position thereof. 
     
     
         9 . The piston-chamber combination according to  claim 6 , wherein the cross-sectional 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. 
     
     
         10 . A pump for pumping a fluid, the pump comprising:
 a piston-chamber combination, comprising an elongate chamber which is bounded by an inner chamber wall and comprising a piston means in said chamber,   the piston having a seal thereon that is movable relative to said chamber at least between first and second longitudinal positions of said chamber,   said chamber having cross-sections of different cross-sectional areas at the first and second longitudinal positions of said chamber, and at least substantially continuously differing cross-sectional areas at intermediate longitudinal positions between the first and second longitudinal positions thereof, the cross-sectional area at the first longitudinal position being larger than the cross sectional area at the second longitudinal position,   said piston being designed to adapt itself and the seal to different cross-sectional areas of the chamber during the relative movements of the piston from the first longitudinal position through said intermediate longitudinal positions to the second longitudinal position of said chamber,   wherein the cross-sections of the different cross-sectional areas have different cross-sectional shapes, the change in cross-sectional shape of the chamber being continuous between the first and second longitudinal positions of the chamber,   wherein the piston is further designed to adapt itself and the seal to the different cross-sectional shapes,   wherein a first circumferential length of the cross-sectional shape of the chamber at the first longitudinal position thereof amounts to 80-120% of a second circumferential length of the cross-sectional shape of the chamber at the second longitudinal position thereof,   further including a mechanism engaging the piston from a position outside the chamber, and   a fluid entrance connected to the chamber and comprising a valve assembly, and a fluid exit connected to the chamber.   
     
     
         11 . The pump according to  claim 10 , wherein the engaging mechanism has 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. 
     
     
         12 . The pump according to  claim 10 , wherein the engaging mechanism has 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. 
     
     
         13 . A shock absorber comprising:
 a piston-chamber comprising an elongate chamber which is bounded by an inner chamber wall and comprising a piston means in said chamber,   the piston having a seal thereon that is movable relative to said chamber at least between first and second longitudinal positions of said chamber,   said chamber having cross-sections of different cross-sectional areas at the first and second longitudinal positions of said chamber, and at least substantially continuously differing cross-sectional areas at intermediate longitudinal positions between the first and second longitudinal positions thereof, the cross-sectional area at the first longitudinal position being larger than the cross sectional area at the second longitudinal position,   said piston being designed to adapt itself and the seal to different cross-sectional areas of the chamber during the relative movements of the piston from the first longitudinal position through said intermediate longitudinal positions to the second longitudinal position of said chamber,   wherein the cross-sections of the different cross-sectional areas have different cross-sectional shapes, the change in cross-sectional shape of the chamber being continuous between the first and second longitudinal positions of the chamber,   wherein the piston is father designed to adapt itself and the seal to the different cross-sectional shapes, and   wherein a first circumferential length of the cross-sectional shape of the chamber at the first longitudinal position thereof amounts to 80-120% of a second circumferential length of the cross-sectional shape of the chamber at the second longitudinal position thereof,   further including a mechanism for engaging the piston from a position outside the chamber, wherein the engaging mechanism has an outer position where the piston is at the first longitudinal position of the chamber, and an inner position where the piston means is at the second longitudinal position.   
     
     
         14 . The shock absorber according to  claim 13 , further comprising a fluid entrance connected to the chamber and comprising a valve assembly. 
     
     
         15 . The shock absorber according to  claim 13 , further comprising a fluid exit connected to the chamber and comprising a valve assembly. 
     
     
         16 . The shock absorber according to  claim 13 , wherein the chamber and the piston form an at least substantially sealed cavity including a fluid, the fluid being compressed when the piston moves from the first to the second longitudinal positions of the chamber. 
     
     
         17 . The shock absorber according to  claim 13 , further comprising a biasing device to bias the piston means toward the first longitudinal position of the chamber. 
     
     
         18 . An actuator comprising:
 a piston-chamber combination comprising an elongate chamber which is bounded by an inner chamber wall and comprising a piston means in said chamber,   the piston having a seal thereon that is movable relative to said chamber at least between first and second longitudinal positions of said chamber,   said chamber having cross-sections of different cross-sectional areas at the first and second longitudinal positions of said chamber, and at least substantially continuously differing cross-sectional areas at intermediate longitudinal positions between the first and second longitudinal positions thereof, the cross-sectional area at the first longitudinal position being larger than the cross sectional area at the second longitudinal position,   said piston being designed to adapt itself and the seal to different cross-sectional areas of the chamber during the relative movements of the piston from the first longitudinal position through said intermediate longitudinal positions to the second longitudinal position of said chamber,   wherein the cross-sections of the different cross-sectional areas have different cross-sectional shapes, the change in cross-sectional shape of the chamber being continuous between the first and second longitudinal positions of the chamber,   wherein the piston is further designed to adapt itself and the seal to the different cross-sectional shapes, and   wherein a first circumferential length of the cross-sectional shape of the chamber at the first longitudinal position thereof amounts to 80-120% of a second circumferential length of the cross-sectional shape of the chamber at the second longitudinal position thereof,   further comprising a mechanism engaging the piston from a positron outside the chamber, and   a fluid source to introduce fluid into the chamber sufficient to displace the piston between the first and the second longitudinal positions of the chamber.   
     
     
         19 . The actuator according to  claim 18 , further comprising a fluid entrance connected to the chamber and an entry valve assembly. 
     
     
         20 . The actuator according to  claim 19 , further comprising a fluid exit connected to the chamber and an exit valve assembly. 
     
     
         21 . The actuator according to  claim 18 , further comprising a biasing device to bias the piston toward the first or second longitudinal position of the chamber. 
     
     
         22 . The actuator according  claim 18 , wherein the fluid source introduces pressurized fluid into the chamber. 
     
     
         23 . The actuator according to  claim 18 , wherein the fluid source introduces a combustible fluid into the chamber, and wherein the actuator further comprises a combustion device to ignite the combustible fluid. 
     
     
         24 . The actuator according to  claim 18 , further comprising a crank adapted to translate the translation of the piston into a rotation of the crank.