Abstract: A brake structure for a roll-up door includes a brake drum fixed to a transmission shaft of a speed reducer. The brake drum receives a pair of brake shoes in opposite inner sides thereof. The brake shoes are pivotably connected to each other at an end of each brake shoe. A linking resilient member is connected between the free ends of the brake shoes. A brake pad is attached to a surface of each brake shoe facing the inner surface of the brake drum. A controlling lever is disposed at the top of the speed reducer corresponding to the free ends of the brake shoes. One end of the controlling lever is connected to an end of a fixing resilient member. The other end of the fixing resilient member is connected to a moving iron of a first solenoid. A clasping block is connected to the moving iron of the first solenoid. The other end of the controlling lever is connected to a moving iron of a second solenoid.

Abstract: A mechanism for controlling the raising and lowering of a door comprising a speed reduction gearing, a high speed input shaft and a low speed output shaft connected to the gearing, and a governor mounted on the input shaft for regulating the input shaft's rotational speed. More particularly, the mechanism is provided with a brake having a movable brake shoe, a temperature sensitive link and an elongate member having a central portion coupled to the brake shoe. As well, the first portion of the elongate member is engageable with the temperature sensitive element and a second portion of the elongate member is engageable with the actuator. In this way, the elongate member is provided for moving the brake shoe to the release position in response to one of (1) the temperature sensitive link upon the temperature reaching a predetermined temperature and (2) the actuator.

Abstract: A mechanism for controlling the raising and lowering of a door comprises a speed reduction gearing, a high speed input shaft and a low speed output shaft connected to the gearing, a governor mounted on the input shaft for regulating the input shaft's rotational speed whereby also regulating the output shaft's rotational speed, a first mechanism for operatively connecting the input shaft to a second mechanism for rotating the input shaft, a mechanism for operatively connecting the output shaft to a slatted retractable door, a brake for preventing rotation of the output shaft, and a release-mechanism the brake to permit rotation of the output shaft.