| 摘要 |
<p>The retraction stroke of a piston and rod (16) is limited by a valve (26) which closes the port to the head chamber (20) of the cyclinder (12). The valve (26) comprises a poppet which is biased to close by a spring but is normally held open by the tensions in a cable (70) extending through a hose (33) from the valve (26) to a fitting (60) closing the distal end of the hose, in which the end of the cable (70) is anchored. The hose is given a slightly sinuous form and tensions the cable (70) by its natural tendency to extend and by virtue of the fluid pressure which is communicated to the inside of the hose from the valve (26). The fitting (60) is supported by a bracket (50) which is moved in by a stop on the piston rod (16) at the end of the retraction stroke to remove the tension from the cable (70) and thereby allow the valve (26) to close and shut off the chamber (20) to prevent further retraction. </p> |
