Patent ID: 9010026
Filing Date: 2015-04-21
Classification: E05F,E05Y,E06B

Abstract:
1. A movable barrier apparatus comprising: a flexible driven member having a leading portion and a trailing portion each of which is configured to connect to a movable barrier which is configured to move between a first limit position and a second limit position; a movable barrier operator comprising a revolving drive, the revolving drive disposed between the leading and trailing portions of the flexible driven member and configured to rotate about an axis causing the leading portion of the flexible driven member to move in a forward direction which causes the leading portion to be paid out from the revolving drive, the trailing portion to be pulled toward the revolving drive and the movable barrier to move toward the first limit position, the movable barrier operator further configured to move the leading portion of the flexible driven member in a reverse direction opposite to the forward direction by moving the leading portion of the flexible driven member toward the revolving drive while moving the trailing portion of the flexible driven member away from the revolving drive to move the movable barrier laterally along a horizontal surface toward the second limit position, wherein the movement of the trailing portion of the flexible driven member away from the revolving drive effects a horizontal force on the movable barrier to effect the movement of the movable barrier toward the second limit position during all of the movement of the movable barrier toward the second limit position, wherein the movable barrier operator is configured to stop moving the movable barrier in response to the movable barrier arriving at the first or second limit positions, wherein the leading portion of the flexible driven member extends along a majority of a length of the movable barrier when said movable barrier is in said first limit position and the trailing portion extends along a portion of the length of the movable barrier, the length extending along the horizontal surface; and a movable barrier controller operatively coupled to the movable barrier operator, the movable barrier controller being configured to cause the revolving drive of the movable barrier operator to move the leading portion of the flexible driven member in the reverse direction a distance toward the revolving drive by rotating the revolving drive about the axis when the movable barrier is in the first limit position without moving the movable barrier to reduce sag in the leading portion of the flexible driven member.