| 摘要 |
437,245. Door-operating appliances. NATIONAL PNEUMATIC CO., 420, Lexing- ton Avenue, New York, U.S.A. April 26, 1935, No. 12572. Convention date, Sept. 26, 1934. [Class 65 (i)] The circuit of a valve 16 controlling a door-opening motor is successively closed when a person passes from left to right by the opening of barriers 5 and the depression of treadles 3, 2. The opening of the barrier 5 energizes a switch solenoid 7 and closes a contact 9 in the motor valve circuit 15. When the treadle 3 is depressed the energization of the solenoid 7 is maintained by a wire 14, wire 18, switch of treadle 3, wire 12, contact 8 and wire 11. When the treadle 2 is depressed the current passes direct to the valve 16 by the wire 14, the wire 18, the switch of treadle 2 and wire 17. The treadle 2 extends further to the side the door opens to enable the person to clear the doors before they close. |
