Patent GB-1333596-A (GB)
Title: Pneumatic message tube systems
IPC: B65G53/56
Filed: 1970-03-31
Abstract: 1333596 Pneumatic shuttle conveyer J W HALPERN and W WARD 19 April 1971 [31 March 1970] 15101/70 Heading B8A In a pneumatic shuttle conveyer system having a main tube to which branch tubes are connected by switched junctions (see Fig. 6) and each branch terminates in a station for both dispatch and receipt of shuttles open to the atmosphere, a shuttle is loaded into a holder at a station after its destination has been set on a dial or push buttons (Fig. 8, not shown) and then a central control unit clears a route to the destination, moves the holder into the dispatch position and dispatches it, and finally returns the holder to the loading position either immediately on dispatch or when the shuttle reaches a sensor in the main tube. In the first embodiment, Fig. 1, the shuttle is dropped through opening 2 into holder 8 and operates switch 10 which causes the central control unit to search for the station having a shuttle for dispatch. On finding the station the control unit reads the selected destination and, after switching the tube junctions to provide a suitable route for it, starts motor 13 to drive holder 8 into position under branch tube 3 whence the shuttle is sucked into the system, the flexible collar 11 forming a seal against the end of the tube. Holder 8 is driven between end stops 14, 15 and limit switches 16, 17 by a threaded rod screwed through holder mounting 5 and rotated through friction coupling 12 by motor 13. A similar mounting (7, not shown) slides on smooth rod (6) parallel to rod 4. Shuttles arriving at the station come to rest against buffer 21 after passing down slide 19 and operating switch SB to reset the control unit for a further transmission. In a second embodiment, Fig. 5, the shuttle is placed in a part-cylindrical holder 33 pivoted to a portion 30 carrying two sealing strips against which holder 33 closes to form a complete cylinder in the dispatch position. The holder 33 is rotated by a motor connected to its pivot pin by a flexible drive. When this embodiment is used horizontally, as shown, the clearance between portion 33f and the shroud 43 is made less than diameter of a shuttle so that the shuttle cannot be placed directly into portion 30. Braking of the shuttles as they approach their destination is achieved by a shuttle operating a switch as it passes into the branch tube 53, Fig. 6, of its receiving station, which switch causes the air flow to be stopped by the central control unit after a delay which is adjustable by a variable resistor at the receiving station. The air flow in branch 53 is stopped by switching over junction tube 64 from that tube to tube 52 and thereby closing off the end of tube 53 with flap 57 which is hinged to and operated by a lever 55 on tube 54. If the shuttle fails to operate the switch at branch tube 53 of its receiving station within a short time, indicating that it has not been sucessfully dispatched, the control circuit will reset itself for a further transmission. If the shuttle operates that switch but not the final switch SB the control circuit will switch junction tube 54 over to re-apply pressure to the branch to expel the shuttle.