| 摘要 |
A load operating mechanism, for a load (2) pivotted about a horizontal line, comprises a pivoted wedge (3) having an operative end 5 engageable with the load 2 and a profiled edge (6) extending between its axis of pivot 4 and its operative end 5, a first linear actuator (8) having a wheel 7 which acts against the profiled edge (6) so that activation of the actuator (8) urges the operative end 5 of The wedge (3) against the load (2) and a cable (11) which is attached to the load (2), extends around a fixed pulley (13) and wheel (7) and is attached to a second linear actuator (12). Activation of actuator (12) serves to urge the load (2) in the direction opposite to that in which it is urged by activation of actuator (8) and serves to retract actuator (8). The actuators are pneumatic or hydraulic. Actuator 8 may be a sealed gas spring. Actuator 12 may be a pneumatic cylinder controlled by a smoke detector, fire alarm or manual switch. The load operating mechanism may be a window, shutter or hatch opening mechanism. The cable may include rope, wire, string or twine or belting. <IMAGE> |
