| 摘要 |
<p>PURPOSE:To greatly reduce actuation time of a piston in the returning direction by connecting a chamber where a spring is disposed with external oil through a one-way valve. CONSTITUTION:A spring 57 to energize a piston member 53 forward is disposed in the right chamber 52 of a hydraulic piston 50, and the right chamber 52 is connected with an external oil sump 58 through a one-way valve 59 which only allows oil flow from the oil sump 58 to the right chamber 52. Thus, when piston member 53 is actuated by force of the spring, oil is sucked smoothly from the oil sump 58 through the one-way valve 59 by negative pressure produced in the right chamber 52, and actuation time of the piston member 53 in the returning direction can be greatly reduced.</p> |
