| 摘要 |
PROBLEM TO BE SOLVED: To eliminate oil leakage from a door closer irrespective of whether or not only hydraulic oil is set so as to be present by discharging air put in a cylinder, and prevent a buffer action from being degraded by the presence of entrained air, or the stopping angle of a closer stopper from being displaced. SOLUTION: A piston 2 is inserted into a cylinder 1 which is sealing-filled with hydraulic oil, the cylinder 1 is partitioned into the high-pressure side of the first chamber 11 and the low-pressure side of the second chamber 12, and a return spring 3 is mounted in the second chamber 12. A bottomed pressure governing tube 5 which opens in the second chamber 12 is mounted in the cylinder 1, and a pressure regulating plug 6 around which an O-ring 7 is wound is slidably-fitted in the pressure governing tube 5 with gas sealed in the pressure governing tube 5 to fill the cylinder 1 with only the hydraulic oil without mixing of air bubbles.
|
