Patent ID: 7025106

Claim:
A door assembly comprising: a door frame having a door jamb and defining a central opening therein through which ingress and egress can occur; a door slidable in the door frame between a door open position permitting travel through the central opening and a door closed position obstructing travel through the central opening; and an automatic closure system comprising: a cable with a first end and a second end, wherein the first end is mounted to an upper portion of the sliding door; a counterweight connected at the second end of the cable and movable along a path between a counterweight open position when the sliding door is in the door open position and a counterweight closed position when the sliding door is in the door closed position, wherein the counterweight open position is above the counterweight closed position; and a pulley mounted to the door frame for redirecting the cable from a generally horizontal orientation near the first end to a generally vertical orientation near the second end; and an adjuster to control movement of the counterweight between the counterweight open and counterweight closed positions and comprising an arm having an end thereof fixedly mounted in relation to the frame and extending into the path of the counterweight; wherein when a force is applied to the sliding door to cause the sliding door to slide to the door open position, the counterweight is elevated from the counterweight closed position along the path to the counterweight open position by virtue of the attachment of the cable to the sliding door via the pulley, and when the force is released, the arm abuts the counterweight and imparts a damping force to the counterweight as it descends along the path to the counterweight closed position to slow movement of the counterweight as it returns the sliding door to the door closed position.