Patent ID: 8650801
Filing Date: 2014-02-18
Classification: E05F

Abstract:
1. A counterweight mechanism for applying a closing urging force at a first condition to a door and an opening urging force at a second, different condition to the door, the counterweight mechanism including: a series of movable elements operatively connected in sequence and at least one of the elements extending directly from the door, the series of elements moving during movement of the door; and a radial arm and a weight fixed to the radial arm, the radial arm and weight being pivotally supported and operatively directly connected to another one of the series of elements, with the series of elements interposed between the door and the radial arm and weight, for movement of the radial arm and weight during movement of the door and the series of elements, the weight being responsive to gravity and providing the closing urging force, via force applied by the radial arm to the series of elements in a first direction, that is transmitted through the radial arm and the series of elements to the door when the weight is in a first position, the closing urging force being reduced as the weight moves toward a second position, and the weight being responsive to gravity and providing the opening urging force, via force applied by the radial arm to the series of elements in a second direction that is opposite to the first direction, when the weight is in a third position, the second position of the weight is an over-center position relative to a pivot of the radial arm and weight and in which the weight does not provide the closing urging force or the opening urging force.