Damping mechanism for hydraulic piston at end position - has radially resilient ring serving as throttle in annular groove in fluid outlet wall, with apertures in ring to facilitate return flow

摘要

A cylindrical throttle (18) enters an outlet opening n6) in the end wall (5) of the hydraulic cylinder (14) ahead of the piston. A ring (22) is mounted with axial play in an annular groove (23) in the wall of the outlet opening. The ring services as a return valve. As the piston approaches its end position, the ring engages the two walls of the groove that are respectively furthest from the piston and parallel to the piston, restricting the otward flow of the hydraulic fluid. When the piston returns, the ring allows fluid to flow in the opposite direction, into the cylinder. The ring is radially resilient and has circumferentially distributed apertures. When the piston returns, fluid flows axially through the apertures.