Patent ID: 7600553

Claim:
A safety device for a closing installation comprising: a mechanism for driving a screen body for selectively closing an opening, said mechanism including: a shaft for winding and unwinding said screen body, an element having teeth, said element being mounted to said shaft, at least one catch which successively contacts said teeth and oscillates over said teeth of said element to permit rotational movements of said shaft as said screen body is being unwound, and a braking means for braking said at least one catch by preventing further oscillation of said at least one catch and causing said at least one catch to engage said teeth of said element in a non-oscillating manner to thereby cause said shaft to be immobilized, said braking means being controlled by a detection means for detecting a failure of a compensating means for compensating for a torque exerted on said shaft by said screen body, and said braking means having a shoe axially moveable along an axis (X-X′) with respect to said shaft and adapted to come into abutment against said at least one catch.