GB478807A - Improvements in pneumatic tube conveyors - Google Patents

Abstract

478,807. Pneumatic despatch apparatus. TELEPHON - APPARAT - FABRIK E. ZWIETUSCH & CO., GES. Aug. 27, 1937, No. 23543. Convention date, Dec. 24, 1936. [Class 78 (i)] The receiver 9 of an intermediate station of a pneumatic tube conveyer is connected to a junction box 4 by two pipes 7, 8. The main conveyer tube 1 is interrupted in the junction box and the two portions are normally connected together by a switch tube 10 pivoted at 11 to the incoming tube and connected thereto by an air-tight connection 13. A spring-pressed slidable sleeve 12 mounted on the outgoing tube fits over the other end of the switch tube, and a corresponding sleeve is mounted on the end of the pipe 7 within the junction box. When a carrier is to be discharged from thereceiver 9, the operator completes a circuit to a solenoid 15, energization of which retracts the two sleeves 12 through the linkage shown and holds them retracted against the springs 16. As the sleeve on the tube 1 arrives in its retracted position, it completes a circuit to another solenoid 14 which causes the switch tube 10 to be rotated counterclockwise against a spring 17 to a position in which it is in alignment with the pipe 7. When in this position the switch tube breaks the circuit to the solenoid 15 and the sleeves 12 are pushed forward by their springs 16 so that the switch tube is now connected to the pipe 7. Forward movement of the sleeve 12 on the outgoing tube 1 breaks the circuit to the solenoid 14, but the switch tube remains connected to the pipe 7 through the sleeve 12 thereon. The arrival of the carrier in the receiver 9 again completes a circuit to the solenoid 15 to retract the sleeves 12 again, whereupon the switch tube 10 is restored by its spring 17 to its normal position, the retraction of the sleeves on this second occasion not energizing the solenoid 14 as the circuit thereto is broken by the movement of the carrier, the carrier finally breaks the circuit to the solenoid 15 so that the sleeves 12 are now restored by their springs and the main conveyer tube 1 recompleted. The carrier now rests in the receiver on a pivoted flap 21 biassed upwardly by a spring 20. A pressure relief valve 34 in the junction box equalizes the air-pressure on both sides of the flap which is now depressed by the weight of the carrier against the spring 20 and so releases the carrier.