UNIDIRECTIONAL MECHANICAL FRICTION BRAKE FOR THE SMOOTH RETURN OF A ROLLER SCREEN

摘要

It is disclosed herein a brake mechanism designed for the control and the damping of the return speed of a roller screen bearing at its end a spring assisting its automatic return to the initial position. The mechanism is internally incorporated to the shaft 1 of the screen, is composed of the nut 2 rotating along with the shaft 1 and is urged in axial movement onto the thread of the steady screw 3. The movement of the nut involves the length modification of the spring 4 and the creation of friction between friction element 5 and ratchet 6 as well as on the surface between ratchet 6 and friction element 7. Throughout the screen's descending, the ratchet allows the free rotation of the shaft 1 of the screen by braking the screen only in thephase of its ascending. The initial position of the nut 2 defines in relationship to the spring both the initial tensing and the braking force that will be developed at the friction elements.