| 摘要 |
A door closer for mounting on a door leaf or frame has a rotatable closer shaft 7 actuable in a closing direction by a spring arrangement 2, 16. An actuating arm is coupled to an end 6 of the shaft 7 to pivot therewith so that a slide block on the actuating arm is slidably displaceable in a slide bar for mounting in a door frame or leaf (as the case may be). The closer shaft 7 is connected to a rotatable cam 10. An opening piston 9 biased by spring 2 acts on faces of the cam 10 through a roller 11 and a damping piston 13 biased by spring 16 acts on the faces of cam 10 through a roller 12. The faces 31, 32 of the cam 10 are profiled so that the reaction of the spring biased pistons 9, 13 thereon provides the closer with a torque which decreases as the door opens. <IMAGE> |
