Patent ID: 6189266
Filing Date: 2001-02-20
Classification: E05D,E05Y

Abstract:
A safety brake mechanism for use at the lower corner of an overhead sectional door having rollers running in guide tracks positioned at each side of the door, each track having a front end wall, the door being lifted by tensioned lift cables extending upwardly from its lower corners, comprising:a bracket for attachment to one lower corner of the door adjacent one of the tracks;a brake shaft having a longitudinal axis and inner and outer ends, the brake shaft being rotatably mounted to the bracket so that it is adapted to rotate about its axis between non-braking and braking positions, the outer end of the brake shaft having a cam member secured thereto, the cam member having at least one tooth, positioned below the brake shaft, downwardly and rearwardly directed toward the door surface, at its outer end, operative to angularly engage the front end wall of the adjacent track with a wedging biting action when the brake shaft rotates to the breaking position;an arm protruding upwardly from the brake shaft inwardly of the cam member, the arm having means for engaging with a lift cable;a torsion spring mounted on the brake shaft;means, rotatably mounted on the brake shaft and being connected with one end of the torsion spring, for adjusting the tension of the spring, said means being disengagably secured to the bracket to affix said one spring;means for affixing the other end of the torsion spring to the brake shaft;the brake shaft being positioned upwardly and forwardly of the roller shaft so that, when mounted to a door in use, the roller can be positioned in the adjacent track and the teeth are positioned outside and forwardly of the track;so that the spring will normally urge the brake shaft to rotate to bring the teeth into angular engagement with the track front end wall but the arm will prevent such rotation as long as the lift cable with which it is engaged is tensioned.