Patent ID: 7228883
Filing Date: 2007-06-12
Classification: E05F,E05Y

Abstract:
1. A movable barrier operator system configured to move a barrier along a path between upper and lower limit positions, the system comprising: a motorized operator which moves the barrier between upper and lower limit positions of the path; and a photo-electric safety system connected to said motorized operator, wherein said safety comprises: a first emitter-receiver pair positioned at a primary obstruction detection height and generating a primary obstruction signal upon detection of an obstruction; and a second emitter-receiver pair positioned at a secondary obstruction detection height and generating a secondary obstruction signal upon detection of an obstruction, wherein said first and second emitter-receiver pairs are connected to one another; and wherein said photo-electric safety systems monitors for obstructions at more than one height along the path, and said motorized operator initiates corrective action upon receipt of one of said primary and said secondary obstruction signals.