Patent ID: 7097003

Claim:
A freight elevator landing door assembly comprising a generally rectangular panel that slides vertically for opening and closing movement, a pair of spaced guide rails adapted to be fixed in parallel alignment to the hoistway walls adjacent opposite vertical sides of an opening served by the door panel, the guide rails each having longitudinally extending vertical faces, the door panel having spaced vertical edges adjacent the guide rails and guide elements adjacent said vertical edges for engaging the guide rails so that the door is guided for movement in a vertical plane by said guide rails, a safety brake fixed on the door panel adjacent each of its vertical edges, the safety brake including a caliper block that extends over opposed vertical faces of the adjacent guide rail and is adapted to be fixed relative to the door, a separate chain for suspending the weight of the door panel adjacent each vertical edge, a wedging element moveable vertically in the caliper block between an inactive position and an active position where it frictionally locks the caliper block and, therefore, the door panel to the guide rail, a biasing spring urging the wedging element to move from the inactive position to the active position, and a control element normally holding the wedge element in an inactive position, the control element being responsive to loss of tension in the chain to release the wedging element and allow it to move to the active position under the influence of the biasing spring.