| 摘要 |
<p>The present invention relates to a multi-stage hydraulic cylinder for providing multi-ple stages of displacement with different cylinder forces, comprising a cylinder housing, a first stage piston slidably received in said cylinder housing to be dis-placed over a first stage of displacement, a second stage piston coupled to said first stage piston to be displaced, together with said first stage piston, over said first stage of displacement and to be displaced relative to said first stage piston over a second stage of displacement, said first stage piston and said second stage piston having pressure surface areas different from each other to provide for said different cylinder forces, and further comprising a cushion arrangement for smoothening stage changes. In accordance with the present invention, the cushion arrangement includes at least one compression chamber of variable volume with a movable and/or deformable chamber wall element to be displaced by at least one of the pis-tons when approaching the transition zone between said first and second stages of displacement, said compression chamber being operatively connected to a gas vol-ume to be compressed upon displacement of said chamber wall element and com-pression of said compression chamber.</p> |
