| 摘要 |
Provided is a control mechanism for use with a door closer having a pinion shaft (18), comprises a coiled torsion spring (22) around the shaft with a free end of the spring lying along part of a strap (29), which strap is connected to the shaft and normally held in tension, in use, by its connection to a movable hydraulic piston of the door closer which is biased in one direction. On normal closing of the door, in use, the strap remains tensioned and the spring (22) is thus prevented from tightening on the shaft. However, if an additional, i.e. external, closing force is applied to the door, the strap becomes untensioned, thereby allowing the spring to tighten about the shaft to retard its angular door closing movement. |
