摘要 |
An overhoist prevention system suitable for use on a crane comprises (a) a proximity switch (17), (b) a movable detector plate (10) normally biassed away from the proximity switch, (c) an actuator (5) adapted for use with the hoist wire (4) for moving the detector plate towards the proximity switch and (d) a relay (21). The relay is actuated by a signal from the proximity switch and controls the operation of an alarm and/or the supply of the power to the winding drum of the crane.
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