Patent GB-855344-A (GB)
Title: Improvements in pneumatic message transmission systems
IPC: B65G51/40
Filed: 1956-04-20
Abstract: 855,344. Pneumatic despatch apparatus. HALPERN, J. W., and WARD, W. April 16, 1957 [April 20, 1956; July 16, 1956], Nos. 12145/56 and 21867/56. Class 78 (1). A pneumatic tube system for transmitting messages, which is suitable for light traffic and consists of a main line and a series of branch lines and sub-branch lines, is provided with switching means in the proximity of each branch line, or sub-branch line, which are actuated by the carrier during its travel along the line to alter its direction of travel and to regulate the speed and direction of flow of the transporting medium in accordance with a predetermined routing schedule. The main line ML, Fig. 1, has branch lines a, b, c and is connected at each end to suction pumps P1, P2. A diverter unit d is inserted in the main line at the junction with each branch and contains a guide tube, which normally forms part of the main line, but can be moved to connect it to the branch. Switches x, y are inserted in the main line before each diverter and a switch z in each branch. An air branch tube abr connects the branch to the main line. When a person at station A wishes to send a message to station C, he inserts a carrier in the branch a and then either presses the selector button for station C or dials its number. The pump P1 then comes into operation if the main line is free and causes the guide tube at d to swing to connect the branch to the main line. The carrier is then drawn into the main line. When it passes switch x, the tube returns to its normal position and when it reaches switch y and actuates it, pump P1 is stopped or disconnected from the main line. At the same time pump P2 comes into operation, guide tube at station C swings to communicate with the branch c and the carrier reverses its movement and passes along the main line and into branch c. As it passes switch Z it actuates it to put pump P2 out of action. In a modification one of the pumps is dispensed with and the inlet and outlet of the other pump are connected to the main line through a two-way valve so that either suction or pressure can be produced in the main line. The valve, or several similar valves, are under remote control and can produce various degrees of pressure or suction in the main line. A wiring diagram of a control system is given in the Specification. The movable tube 19, Fig. 7, of the diverters has at each end a tapered piece 5 and a soft rubberbonded ring 8 and can be moved to connect the tubular piece 2a either to a similar piece 2b or to a piece 2c. Pressed cup parts 4, 4a are rubberbonded on the rings 8 and parts 5 and the part 4 is driven by a motor 16 through gearing 14. The outer faces of the rings 8 slide on ground steel rings 3, 25, respectively. Felt pads 35a, 35b, Fig. 8, stop the movement of the tube when it registers with the outlets. If it is desired to connect the right-hand end of the tube 19 to more than two alternative tubes 2b, 2c, a modified apparatus shown in Figs. 12 and 13 is used which is described as applied to three outlets, but can be used for more. Fig. 12 is a sectional view through the left-hand end of the diverter. The tube 151 carries a flanged metal drum 152 covered with frictional material which is engaged tightly by a belt or chain 154 driven by a motor. An annular frame 159 carries pins 160<SP>1</SP>, 160<SP>2</SP> and 160<SP>3</SP> on each of which is mounted a triangular shaped lever such as 161<SP>3</SP>. One side 161a of each lever is covered with felt and each lever is connected to the frame 159 by a spring 162<SP>3</SP>. Each lever is connected also to an electromagnet 163<SP>3</SP> which, when actuated, moves the lever into the position shown in broken lines. In this position it is in the path of the stop 158 mounted on the drum 152, and on reaching it the movable tube is in register with the selected tube. Specification 714,143 is referred to.