Patent attributes
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. A controlling block is disposed at the controlling lever between the free ends of the brake shoes and in contact to the free ends of the brake shoes. A brake control solenoid is disposed at the top of the speed reducer. The brake control solenoid is connected to a power supply with capacitance character. A moving iron of the brake control solenoid is connected to a connecting rod mechanism. The clasping block is connected to the connecting rod mechanism.