| 摘要 |
PURPOSE:To make it possible to maintain the turning manipulation of a shut-off member constant even though gas pressure is affected by variations in temperature, by providing a gas pressure regulating means for regulating the pressure of gas charged in a cylinder. CONSTITUTION:A regulating means 20 have a sub-tank 22 and a pressure regulating piston 23 is communicated with one 8 of gas chambers in a cylinder 6 so that it contains therein gas 5. An adjusting screw 24 on one end face of a pressure regulating piston 23 is engaged with a female-threaded guide member 25 secured to the sub-tank 22 so as to secure a manipulating knob 26. When the atmospheric temperature lowers so that the gas reaction force by a gas spring 4 is decreased, the effective volume of the sub-tank 22 is decreased by means of the adjusting screw 24 to increase the gas pressure in the cylinder 6 so that the gas reaction force is increased. When the atmospheric temperature rises, the gas pressure is lowered contrarily so as to decrease the gas reaction force. Thus, the gas reaction of the gas spring may be steplessly adjusted by simply rotating the adjusting screw, thereby it is possible to adjust assisting force for a shut-off member to a suitable degree. |
