| 摘要 |
A door closer for mounting between a door leaf and a door frame, the door closer comprising: an elongate housing 2 for mounting in one of the door leaf or door frame, a plunger 6 disposed in and movable along the housing 2, a biasing element 4, which may be a helical compression spring, disposed in the housing 2 and biasing the plunger 6 inwardly of the housing 2, and a tension member 14 having a first end 16 connected to the plunger 6 and a second end 20 connected to an anchor element assembly 24, the anchor element assembly comprising a mounting member 20, for mounting in the other of the door leaf or door frame, and a hydraulic damper 50 for damping the movement of the plunger 6 within the housing 2, the hydraulic damper 50 comprising a hydraulic fluid selected from a glycol-based fluid or a silicone-base fluid since their viscosity is less susceptible to changes in operating temperature. The hydraulic fluid is preferably a glycol-based brake fluid such as DOT 3, 4, or 5.1 as used in automobiles. The door closer is not limited to glycol-based or silicone-based fluids, in which case the hydraulic damper further comprises a restrictor valve having a threaded adjuster pin 52, including a needle valve member 55, which can be screwed in and out to adjust the flow of fluid in the damper; the needle valve 55 has a tapered surface at angle of less than 1 degree, alternatively it may have an angle of no greater than 2.5 degrees if a fluid having a viscosity in the range 750cP to 2000cP at minus 40 degrees centigrade is used. |
