| 摘要 |
<p>An automatic operating system for swinging doors which is controlled by the user by means of a miniature, hand-held radio transmitter having a a single operating pushbutton. Depression of the pushbutton results, sequentially, in the retraction of the deadbolt, the retraction of the main latch, and the opening of the door. The door then remains open until the pushbutton is again depressed, whereupon the main latch is extended, the door is swung to its closed position, the deadbolt air pressure in the automatic door operating system is bled to atmospheric level, resetting the system to its normal or quiescent state.</p> |
