Abstract: A security unit for a hanging stage scaffolding motorized by two electric winches of which each is supplied through a control circuit, said stage having a platform or gondola directly or indirectly suspended by two lugs pivotally mounted on each of said winches, respectively, characterized in that each lug carries a pin adapted to penetrate a slit in a slide to move towards the left or right said slide according to the default of the gondola to the horizontal, the displacement of said slide being adapted to bring it in contact with the opening thereof.

Abstract: The tractive apparatus has two clamping grippers each comprising a pair of jaws actuated by clamping links connected to an operating lever through connecting links pivotably mounted on this lever on each side of a pivot pin of the lever situated in the extension of a guide bar on which one of the two jaws of each gripper slides, the two grippers moving in opposite directions while being clamped in one of the two directions of movement. The guide jaw of each gripper is formed by a hollow body which serves as housing and bearing point for one of the ends of a pre-clamping spring whose other end exerts its action on a clamping link actuating the other jaw of the same gripper.

Abstract: This traction apparatus for hauling in and out a rope, of the type comprising a linkage mechanism adapted to actuate by turns two self-clamping pairs of jaws performing alternate to-and-fro movements, comprises a safety release device coupled to one of the levers of the mechanism, this device comprising essentially a push knob for releasing a two-armed strap normally held in locking engagement with the edges of apertures formed in the half-casings of the apparatus, push members associated with the outer bent arms of this strap and a U-shaped rod surrounded by pre-clamping springs and operatively connected to the strap, so that the rope cannot be released by the clamping jaws unless the operator pushes with both hands the push members subsequent to the depression of the push knob.

Abstract: The device, adapted to be associated with a motorized hauling installation, comprises a self-clamping jaws block with a safety cable passing through it onto which the load can be transferred by clamping the jaws. The jaws block is connected by means of control rods to a mobile chassis of which one end is adapted to pivot, in case of a fall, about a fixed point of the casing, this pivoting action activating an electric detector which stops the machine motor. (FIG. 1).

Abstract: The clutch device, adapted to be associated with a traction apparatus provided with a release device comprising two rocking levers, comprises a clutch engaging member associated with one of the rocking levers in order to modify the normal movement of this rocking lever and a clutch control member associated with the other rocking lever and adapted, when actuated, to provide a simultaneous opening of the two clamps of the apparatus.