COMBINAÇÃO DE PISTÃO E CÂMARA

IPC Classification

Abstract

A piston-chamber combination comprising a chamber (1) which is bounded by an inner chamber wall (4), and comprising a piston (1) in said chamber (2) to be engagingly movable relative to said chamber wall (4) at least between a first position and a second position of the chamber (2), said chamber (2) having cross-sections of different cross-sectional areas and differing 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 (1) is comprising an member (12) for suspension of the sealing (8,9), said member (12) is rotatable, and said sealing (8,9) is comprising a separate part (6,6?) engaging the wall (4) of said chamber (2) and a sealing (8,9) made of elastically deformable impervious material, and mounted on the piston rod (5).This is achieved by the piston (1) is produced to have a production-size of said separate part (6?) and said sealing (8,9) in the stress-free and undeformed state thereof in which the circumferential length of the piston (1) is approximately equivalent to the circumferential length of said chamber wall (4) at said second longitudinal position, the piston (1) being expandable from its production size in a direction transversally with respect to the longitudinal / circular direction of the chamber (2) thereby providing for an expansion of sealing (7) of the piston (1) from the production size thereof during the relative movements of the piston from said second longitudinal position to said first longitudinal / circular position, one end, closest to a second longitudinal / circular position of the chamber, the sealing (7,7?) is embedded in a separate part (6,6?), said sealing (8,9) of the piston (1) is comprising sealing sections (19,20; 51,51?) in a direction along the piston rod (5), said sealing (7) is updivided updivided in said sections over the circumference of said sealing (7), and, the angle (¿;¿) in-between two adjacent sealing sections is much less than 180¿, one other end, closest to a first longitudinal / circular position of the chamber, said sealing (7) is updivided updivided in said sections over the circumference of said sealing (7), and, the angle (¿;¿) in-between two adjacent sealing sections is bigger than said angle.Figs. 3B,3C.