Hydraulic damper with double-acting piston - has piston rod passing through loose membrane sealed to it and forming end wall of pot

摘要

The pot (2) containing the piston is filled with hydraulic fluid. The piston rod (5) passes only through one end wall of the pot to the outside, this wall consisting of a loose sealing membrane (7) enclosing and fixed to the rod. The piston can consist of a perforated disc (6) leaving only a narrow peripheral gap (18) between its outer edge and the inside wall (40) of the pot. There can also be a baffle disc (19) at one or both sides of the piston and clear of it. This has an opening (21) for the contact-free passage of the rod through it. ADVANTAGE - Reacts to very slight vibration, being particularly for the vertical oscillation of a footbridge.