Patent ID: 7610719

Claim:
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.