| 摘要 |
PURPOSE: To increase closing force at gate closing final point by forming the diametrically contracted part on one end of an actuating stem and constituting so as to apply axial tension to the actuating stem when a roller lever engages with the diametrically contacted part after a gate stem rises according to progress of closing of a gate. CONSTITUTION: When a closing stroke of a gate 20 makes progress, a pressure fluid is allowed to flow out of a valve chest 32 and a spring 38 pushes up a piston 36 to move a gate stem 28 and a gate 20 upward. When a small roller 104 reaches the round part of an intersection between the surface 94 and a shoulder 42 according to the rise, force of a spring 72 generated in a large roller 106 acts so as to move an actuating stem 44 upward by rotating a lever 64 around a pin 108 by engaging the small roller 104 with a shoulder 92. When the actuating stem 44 rises, large force is generated by a pivotal movement of an arm 102 and increased force is applied to the shoulder 92 according to progress of the pivotal movement to assist the final closing movement of the gate 20. |
