Active brake release device attached to the exterior of a door controller

An active brake release device (1) which is attached to an exterior of a door controller (90) and used to actively shut off a safety door in an event of unexpected electricity failure, wherein said door controller (90) winding said safety door is braked by a brake device (91) and released by a brake release bar (92) extending outwardly, said active brake release device (1) comprising:

• a first electromagnet (20), which is fixed on a base plate (10) and placed on the exterior of the door controller (90), for activating a sliding portion (21) when the first electromagnet (20) is energized;
• a first actuator (40) and a second actuator (50), which are linked to the sliding portion (21), in which the first actuator (40) is abutted against the brake release bar (92), and the second actuator (50) has a cut-off portion (51);
• a first sliding bar (30), located on an opposite side of the first electromagnet (20), one end of which is connected with the sliding portion (21), and the other end of which is yieldingly biased by a first spring (36);
• a limit means (60), one end of which is pivoted on the base plate (10) to swing, and the other end of which is vertically penetrated with a sliding pin (61) and is yieldingly biased by a second spring (66), used to limit the cut-off portion (51) of the second actuator (50) at a fixed point;
• a second electromagnet (70), comprising a second sliding bar (71) for pushing the sliding pin (61) against a spring force of the second spring (66) when the second electromagnet (70) is energized;
• a circuit, which includes a limit-switch (80) switching on the first electromagnet (20) upon resetting the active brake release device (1), and a capacitor which temporarily energizes the second electromagnet (70) in the event of unexpected electricity failure.