| 摘要 |
A safety device, particularly intended for use in roll-up doors for the purpose of causing reversal of the closing movement of the door when an object is obstructing the path of movement of the door. The device comprises at least one signal emitting means which is arranged to emit a beam of light, a beam of sound or another kind of signalling beams and which is supported by the door-leaf some distance from the door-leaf closing edge. The signalling device emits a beam of light, a beam of sound or a signalling beam of another nature across the width of the door-leaf at such a distance from the lower closing edge of the door-leaf that any object that interrupts the beam emitted by the signalling means causes reversal or standstill of the closing movement of the door-leaf before the edge thereof hits the obstructing object. The signalling means is arranged to be displaced towards the lower closing edge of the door-leaf during the final closing movement of the latter. |
