| 摘要 |
<p>The safety appts. is used with lifting units having an electrical motor (MO) to which a drum (1) is connected. The drum has a skirt (2) on which a pull rope (3) is spirally wound. The appts. has a detector to determine the position of the rope in operating conditions and detect shifting, if any, of the rope to an anomalous condition. A device is placed below the skirt and connected to an electric circuit to deactivate the motor. The circuit is 'on' when the rope vertical length, reeling off of the drum, sets itself on the side opposite to the vertical axial pan (b-b) of the drum. The device includes a lever (4) having horizontal rotation axis (z) and being provided with a slotted hole (41) through which the rope (3) is made to pass. A 'V' shaped appendix (42) makes-up a flaring and locking element for the rope when its position changes w.r.t the plane b-b by winding over the skirt in an abnormal direction, so as to cause the rotation of the lever about the pivot axis. A consequent pressure is applied on a switch button (5) connected to the electrical circuit for the motor supply and control.</p> |
