DISPOSITIVO A COMANDO MANUALE, PARTICOLARMENTE PER MANOVRA D'EMERGENZADI PORTE A SCORRIMENTO VERTICALE COMANDATO DALLA ROTAZIONE DI UN RULLO

A manual control device for the emergency operation, especially of vertical moving doors actuated by a roller controlled by a self-braking electric motor 3. On a control shaft 6, which can be made to rotate manually via a remote control device 10, there is mounted an actuator 12, which carries a clutch element 25 and which is moved axially via a cam 28a between a position of rest and an active position in a first phase of the rotation of the control shaft 6, in which the actuator 12 is connected in rotation to the shaft 6 via a first coupling device 16, 17, 18. Said axial displacement results in interruption of the electric circuit of the motor 3, releasing of the brake of the motor 41 and the engagement of the clutch element 25 with a supplemental clutch element 5 carried by the shaft 4 of the electric motor 3. At the end of said axial displacement, the first coupling device 16, 17, 18 is disengaged and a second coupling device 18, 27 is engaged, which connects in rotation the actuator 12 to the control shaft 6, thus allowing the shaft 4 of the electric motor 3 to be entrained in rotation by virtue of a further rotation of the control shaft 6.