Combined transmit and receive pneumatic carrier terminal with mechanical

Abstract

A terminal for transmitting and receiving pneumatic carriers is disclosed having a pneumatic tube section which constitutes an upwardly directed extension of a combined transmit/receive line of a pneumatic tube system. The tube extension section is provided with a carrier insertion/removal opening which is normally closed by a vertically reciprocating door driven from a bidirectional drive mechanism. Also included is a catch pivotally mounted for movement between (a) an inner position projecting into the pneumatic tube extension section for supporting the base of a received carrier and (b) an outer position for permitting unobstructed passage of a carrier between the combined transmit/receive system line and the pneumatic tube extension section which constitutes an extension thereof. A counterweight is connected to the catch through a lost motion mechanism. The counterweight is also connected to the door drive mechanism via a link, e.g., a flexible cable. The link maintains the counterweight in an upper position when the door is closed biasing the catch to its inner position to support a received carrier thereon. The catch, however, is free to momentarily pivot to its outer position when an upwardly moving carrier momentarily passes by in the course of receipt at the terminal. The link between the counterweight and the door actuating mechanism biases the catch to its outer position, allowing unobstructed insertion of the carrier into the tube extension for transmission, when the door is in its open position, except when a received carrier supported by the detent has not yet been manually withdrawn through the open terminal door in which case the weight of the carrier maintains the detent in its inner position.