Abstract
A piston-chamber combination comprising an elongate chamber (70) which is bounded by an inner chamber wall (71,73,75) and comprising a piston means (76,76', 163) 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 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 means 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 means from the first longitudinal position through said intermediate longitudinal positions to the second longitudinal position of said chamber, wherein the piston means (76,76', 163) comprises:a plurality of at least substantially stiff support members (81-,82,184) rotatably fastened to a common member (6,23,45,180), said support members embedded in elastically deformable means (79), supported by said support members, for sealing against the inner wall (71,73,75,155,156,157,158) of the chamber (70) said support members being rotatable between 10° and 40° relative to the longitudinal axis (19) of the chamber (70).
