| 摘要 |
PURPOSE:To simplify the structure considerably by opening/closing a pressure balance valve for feeding pressure into a cylinder by means of piston itself. CONSTITUTION:Only the foot rod 18 of a pressure balance valve 16 for closing the valve port 15 through resilience is projected to a cylinder 2 without projecting a pressure balance sleeve 10 fixed to the delivery chamber 9 side. A press chip 20 for pushing the foot rod 18 to open said valve 15 near the final stage of compression stroke is provided on the piston head. Consequently, only the pressure balance valve 16 is provided movably to function it directly by means of the press chip 20 of piston 3. Since a mechanism for driving said valve 16 is not required independently, the structure can be simplified considerably. Also since the sleeve 10 is not movable, occurrence of faults can be reduced. |
