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

Abstract

A piston-chamber combination has an elongate chamber with a piston movable therein between first and second positions. The chamber has cross-sections of different areas and different circumferential lengths at the two positions, and substantially continuously different cross-sectional areas and circumferential lengths at intermediate positions, area and circumferential length at the second position being smaller than that at the first. The piston is elastically deformable and has other features to adapt to the different cross-sectional areas and circumferential lengths of the chamber during movements of the piston.

1 . A piston-chamber combination comprising an elongate chamber which is bounded by an inner chamber wall, and comprising a piston in said chamber to be sealingly movable relative to said chamber wall at least between a first longitudinal position and a second longitudinal position of the chamber,
 said chamber having cross-sections of different cross-sectional areas and different circumferential lengths at the first and second longitudinal positions, and at least substantially continuously different cross-sectional areas and circumferential lengths at intermediate longitudinal positions between the first and second longitudinal positions, the cross-sectional area and circumferential length at said second longitudinal position being smaller than the cross-sectional area and circumferential length at said first longitudinal position,   said piston comprising an envelope defining an enclosed space, the envelope being elastically deformable thereby providing for different cross-sectional areas and circumferential lengths of the piston adapting the same to said different cross-sectional areas and different circumferential lengths of the chamber during the relative movements of the piston between the first and second longitudinal positions through said intermediate longitudinal positions of the chamber, wherein the piston is produced to have a production-size of the envelope in the stress-free and undeformed state thereof in which the circumferential length of the piston is approximately equivalent to the circumferential length of said chamber at said second longitudinal position, the envelope being expandable from its production size in a direction transversely with respect to the longitudinal direction of the chamber thereby providing for an expansion of the piston from the production size thereof during the relative movements of the piston from said second longitudinal position to said first longitudinal position.   
   
   
       2 . A combination according to  claim 1 , 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. 
   
   
       3 . A combination according to  claim 1 , 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. 
   
   
       4 . A combination according to  claim 1 , 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. 
   
   
       5 . A combination according to  claim 1 , wherein the envelope contains a deformable material. 
   
   
       6 . A combination according to  claim 5 , wherein the piston comprises an enclosed space communicating with the deformable envelope, the enclosed space having a variable volume. 
   
   
       7 . A combination according to  claim 6 , wherein the volume is adjustable. 
   
   
       8 . A combination according to  claim 6 , wherein the enclosed space comprises a spring-biased pressure tuning piston. 
   
   
       9 . A combination according to  claim 1 , wherein the piston includes at least one valve. 
   
   
       10 . A combination according to  claim 9 , wherein the piston comprises a pressure source. 
   
   
       11 . A combination according to  claim 9 , wherein the valve is a check valve. 
   
   
       12 . A combination according to  claim 1 , wherein a foot of the chamber comprises at least one valve. 
   
   
       13 . A combination according to  claim 9 , wherein the valve is a release valve. 
   
   
       14 . A combination according to  claim 1 , including 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. 
   
   
       15 . A combination according to  claim 14 , further comprising a fluid entrance connected to the chamber and comprising a valve means. 
   
   
       16 . A combination according to  claim 14 , further comprising a fluid exit connected to the chamber and comprising a valve means. 
   
   
       17 . A combination according to  claim 14 , 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. 
   
   
       18 . A combination according to  claim 14 , further comprising means for biasing the piston toward the first longitudinal position of the chamber. 
   
   
       19 . A combination according to  claim 1 , including 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. 
   
   
       20 . A combination according to  claim 19 , wherein the means for introducing fluid comprises a fluid entrance connected to the chamber including a valve. 
   
   
       21 . A combination according to  claim 19 , wherein the means for introducing fluid comprises a fluid exit connected to the chamber and a valve. 
   
   
       22 . A combination according to  claim 19 , further comprising means for biasing the piston toward the first or second longitudinal position of the chamber. 
   
   
       23 . A combination according to  claim 19 , wherein the introducing means comprises means for introducing pressurized fluid into the chamber. 
   
   
       24 . A combination according to  claim 19 , further comprising a crank adapted to translate the translation of the piston into a rotation of the crank. 
   
   
       25 . A combination according to  claim 6 , wherein the enclosed space consists of a first and a second enclosed space.