| 摘要 |
An automatic door or window closing device which includes a tube attached to the edge of a movable door or window. The tube has a weight displaced therein with a cable attached at the top which passes out of the top of the tube across a pulley and is connected to the door or window jamb. A pneumatic seal is provided between the weight and the inside wall of the tube and works in conjunction with a port and valve at the bottom of the tube for controlling the flow of air passing therethrough. When the door or window is opened, the weight rises in the tube. When the door or window is released, the weight drops in the tube according to the adjustment of the port and valve at the bottom of the tube, until the door or window is completely closed. |
