| 摘要 |
A hydraulic cylinder 2 comprises fluid chambers 18, 20 split by piston 4, a piston rod 6 and two valves biased closed by magnetism which allow flow in opposite directions in response to pressure differentials between chambers 18 and 20. Springs 30, 50 may restrict the opening of the valves. The valves may have sloped grooves 40, 52 such that the restriction valve members 28, 42 place on the flow decreases the further they are from their seats. Valve 42-54 may be opened by projection 54 of member 42 contacting a buffer 14 located in chamber 20 which is biased by spring 16 against piston 4. Buffer 14 may magnetically attract extended member 40 to open valve 28-40. The distal end of cylinder 2 may have grooves (62, fig. 9) providing a flow bypass around piston 4 and a gas-filled compensation chamber 10 defined by moveable wall 12. The other end of cylinder 2 may have hydroelastic (64, figs. 10 and 11) or hydraulic 26 damping means to stop piston 4. Fixings 70, 72 may be provided to separate from cylinder 2 under excessive force to allow piston 4 to be operated. Seals 38 may be provided to damp noise when valve 28-40 closes. |
