Device for opening and closing of cord operated closures

摘要

A device for the opening and closing of cord operated closures, including a unidirectional electric drive motor and a pair of movable idler pulleys. The drive motor drives a frictional drive roller. A pair of flexible cords from the closure are singularly held against the drive roller by moving one or the other of the idler pulleys against the drive roller sandwiching a cord therebetween, one idler pulley causing one cord to move in one direction and the other idler pulley causing the cord to move in the other direction. An automatic shutoff mechanism is incorporated to shut off the drive motor and release the cord when sufficient tension is present on the cord, for instance, at the end of closure travel. The shutoff mechanism causes the drive roller and associated mechanism to travel along the cord a short distance thereby triggering a latch release mechanism.