Patent attributes
This invention relates to a type of safety door central release device which can be used to close the safety door automatically when electric power is disrupted. It comprises a cord that is tied to a mechanism having potential energy on one end, and extended to a far distance on the other end; a pair of crank arms of which one end molded as a grip and gripping the cord, and the other end is connected to a sliding bar, having potential energy which assists the grip in release the cord. When electric power is supplied, the sliding bar will be attracted to an electromagnet. As a result, while electric power is disrupted, the release device can immediately release the cord. Due to release of the cord, a brake for a door operator is released by means of the mechanism such that the safety door slides down and then it is closed.