| 摘要 |
A clutch device for the hoisting machinery for a door or the like, which device comprises a primary shaft (2), which is connected to a driving motor via a gearing, and a secondary shaft (4), which carries the hoisting means for the door. For the purpose of manual operation the device comprises a clutch between said secondary shaft (4) and said gearing, said clutch comprising a clutch disc (9) movable in axial direction. The clutch disc (9) preferably comprises clutch teeth (10) having contact flanks (11, 12) extending essentially in the direction of said shaft (4) and acting perpendicularly to said direction. The flanks (11, 12) have different dimensions in the direction of said shaft (4). The invention also relates to a method for controlling the movement of said secondary shaft (4), wherein said clutch disc (9) is displaced so far in the direction of said shaft (4), that a shorter one (11) of flanks (11, 12) of said teeth (10), the peripheral cross section of which is formed as an orthogonal trapezium with unequal sides will be disconnected from an engagement with one flank (7) of a notch (6) in a counter piece (5), said engagement being capable of bearing a load in one direction, while the other flank (12) of said tooth (10) still remains in a load bearing contact with the other flank (8) of the same notch (6). |
