Automatic anti-fall device for manual or motorized lifting systems

Automatic safety apparatus adapted to working with a cable passing through it for stopping a load in the event of a breakdown of a motor driven and manual hoisting and pulling system, which comprises

• an automatic cable clamping device 1 consisting of a self-tightening jaw block (11) with two jaws (13), (13') located in the proximity of the cable, said jaws being constantly urged by a pair of spring driven levers (14), (14') to clamp the cable, whereby said jaw actuating levers are pivoted on two flanges (12), (12') parallel to the cable, which are connected with the load by means of a case O of the safety apparatus, as well as--in the case of a motor driven hoisting and pulling system
• an automatic motor(s) stopping device 5 comprising a circuit breaker 51 coupled with the cable clamping device 1, so that, while jaw block 11 is not prevented from clamping the cable, circuit breaker 51 interrupts feeding of the motor(s) driving the hoisting and pulling system, and which comprises besides, on the one hand,
• an engaging device 2 adapted to prevent working of said cable clamping device and of said eventual motor(s) stopping device as long as the relative speed of the safety apparatus and of the cable is lower than a pre-established critical speed, and, on the other hand,
• an automatic releasing device 3 of said automatic cable clamping device and of said eventual motor(s) stopping device, which is actuated by the centrifugal force developing in an inertia block 32 rotated by a driving member 41 of a driving device 4, whereby said driving member directly or indirectly receives itself a rotary motion from the cable, and which is adapted to neutralize the action of said engaging device as soon as the relative speed of the cable and of the safety apparatus attains said critical speed, and
• a manual releasing device 6 being adapted to neutralize the action of said engaging device indepentently from the relative speed of the cable and of the safety apparatus, characterized by the fact that said flanges 12, 12' to which the self-tightening block 11 is linked through its jaw actuating levers 14 are connected with the load directly and/or by means of a case of a hoisting and pulling apparatus A.L. so that the safety apparatus is adapted to work in order to stop the load either, by a breaking of the cable of the hoisting and pulling apparatus, on an auxiliary cable, or, by attaining said critical speed, as well on the cable of the hoisting and pulling apparatus as on an auxiliary cable.