Door opening and closing system.

摘要

The operating mechanism includes a front cable attached to a drive pulley (144) which extends through a guide assembly (54) to a hinge and roller assembly (26). A rear cable attached to the drive pulley (136) extends through the guide assembly (56) to the hinge and the roller assembly (26). The drive pulleys (136,144) each have a large diameter spiral cable groove (164), a small diameter cable groove (208) and a transition cable groove (210). A motor rotates the drive pulleys. The small diameter cable grooves drive the door when the door is in the forward portion of the tracks, and the large diameter spiral cable grooves drive the door when the door is in the centre and rear portions of the track. Fixed idler rollers (226,254) are positioned relative to the cable drive pulleys to insure that the total cable in the continuous cable loop is substantially the same when the cable is driven by the small diameter cable grooves as when the cable is driven by the large diameter spiral cable grooves. A cable tension system (220) maintains cable tension. A slack cable take-up pulley (174) on the drive pulley (136) takes up slack cable to set cable tension and is then locked in position.