| 摘要 |
As clained in 1, 561, 681 is modified in that in the case of a vertical pipe, a sleeve is attached to an upper cover of a hollow piston to bias the spring (through an intermediate ring if necessary), one end of which abuts an axially displaceable flange disposed in the cylinder. This latter fastened with a pipe collapsible telescopically into the sleeve against the bias of the spring. Telescopic movement of the pipe is assisted by a threaded nut disposed slidably in the pipe and mounted on the threaded member of the spindle. Nut abuts a stop inserted into the pipe through its upper end. |
