| 摘要 |
A piston (600) includes a piston housing (601) and a decompression valve (620) disposed in the piston housing. The decompression valve includes a valve housing (630) seated in the piston housing and a valve member (640) moveably received by the valve housing. The valve member (640) has a radially outer surface including an annular shoulder. In addition, the piston includes an end cap (670) secured to the first end of the piston housing. A radially inner surface of the end cap includes an annular valve seat (674). The decompression valve has a closed position with the annular shoulder of the valve member engaging the valve seat of the end cap and an open position with the annular shoulder of the valve member axially spaced from the valve seat of the end cap. The piston also includes a biasing member (660a,660b,660c,660d) configured to bias the decompression valve to the closed position. |
