| 摘要 |
<p>A lift cylinder comprises a cylinder body (1) containing a piston (2), a check valve (4) provided in the piston for allowing only oil flow from an air chamber (A) to a pressure chamber (R) and a cushion ring (21) provided in the piston for producing a cushioning effect near the maximum contraction of the lift cylinder by sliding onto a static cushion guide part (11a). <??>The check valve (4) comprises a tubular valve seat member (41), a poppet valve (42), a spring receiver (44), and a bias spring (43) to bias the poppet valve in a closing direction. The top of the cushion ring (21) is arranged in close proximity to the bottom of the valve seat member (41) so as to prevent the check valve (4) from slipping to any significant extent out of its predetermined position. Thus there is no need to perform the fiddly and difficult assembly step of fitting a snap ring as in the prior art to hold the check valve (4) in position. The check valve (4) may also be preassembled as a cartridge which is slid into position, rather than the components of the check valve (4) being assembled in situ in the piston (2). <IMAGE></p> |
