| 摘要 |
1,022,547. Door operating mechanisms. STANLEY WORKS. Aug. 7, 1963 [Aug. 8, 1962], No. 31121/63. Heading E2M. [Also in Division F2] A door actuator is provided with an overload release clutch 54 Figs. 2 having a rotatable inner hub 52 coupled to a shaft 22 for opening and closing the door and a rotatable ring member 56 positioned concentrically around the hub 52 and driven by a reversible electric motor via reduction gearing 50, 47, crank 46 and drive link 58. Two curved drive segments 60, 62 are pivotally mounted at 64, 66 on the ring 56 for movement towards and away from the hub 52, the segments being provided with a pair of dogs 70 normally engaging in diametrically opposed recesses 72 in the hub 52. The free ends of the drive segments 60, 62 are joined by a pair of toggle links 80, 82 which together with an adjustable compression spring 104, urge the segments inwardly to maintain the dogs 70 in the recesses 72. As the dogs 70 have their inclined faces 107 facing in opposite angular directions, the clutch 54 is bi-directional and torque is primarily transmitted through clutch segment 60 and its dog 70 to the hub 52 when the clutch is moving in a clockwise or door-opening direction and through clutch segment 62 and its dog 70 in the door-closing direction. When the torque transmitted, e.g. in a clockwise direction, exceeds a preselected amount determined by adjustment of the spring 104, the dog 70 of the clutch segment 60 begins to slide outwardly on wall 108 of the recess 72 against the action of the spring 104 acting through the toggle links 80, 82. At the same time the dog 70 of segment 62 will be cammed outwardly by the recess wall 76 of its mating recess until finally the clutch is disengaged. A pedestrian-responsive signal for energizing the electric motor 16, Fig. 1 (not shown) comprises a switch-type contact carpet or a photo-electric sensing system or a manually operated switch. Cam washers and a coil spring located between bearings for the door drive shaft 22 are arranged to increase the load on the motor to damp the movement of the door as it approaches its fully closed and open positions. Further damping is provided by an electric citcuit which places a resistor in parallel with the motor field. In addition a time delay circuit permits the door to "dwell" at the fully open position. The complete door actuating mechanism is mounted as a unit in a header above the doorway and the drive shaft 22 is coupled directly to the pivot shaft of the door. In an alternative arrangement, the actuator is mounted externally of the header and the door is driven through linkage 180, 182, Fig. 5 (not shown) connected respectively to the drive shaft 22 and to a safety arm pivoted at one end to the door normally retained for movement with the door by a latch. |
