Patent GB-190327359-A (GB)
Title: Improvements in Pneumatic Dispatching Tube Systems
Inventor: DINSPEL WILLIAM HENRY
Filed: 1903-12-14
Granted: 1904-06-02
Abstract: 27,359. Dinspel, W. H., and Stoetzel, J. J. Dec. 14. Pneumatic despatch apparatus. -Relates to a pneumatic or vacuum despatch system, which is divided into sections to which power is supplied separately at relay stations, and, if desired, from separate pumping-stations, so that carrier cartridges may be transmitted in close succession without the possibility of their bunching together ; the main exhausting-pumps of the system are put in gear as required by means of vacuum-controlled valves in connection with the pipes of the system. When a cartridge is to be transmitted through one of the two transmission tubes 2 of the system shown in Fig. 1, it is placed under the hinged end cover 33, Fig. 2, behind the gate valve 36, and the lever 48 is drawn down. The air inlet 46 is thus connected through the three-way cock 47 to the bottom, and the suction inlet 49 through the similar cock 50 to the top, of the cylinder 43, so that the piston draws up the valve 36. Towards the end of its travel, a lug 74 on the valve stem 42 opens an air inlet 68 in the bottom of a second cylinder 55, so that the suction produced by the suction connection 71 in the upper end and the pressure in the lower end of this cylinder raise the piston-rod 56. The first movement of this rod acts through the pawl 67, levers 66, 64, and link 65 to break the toggle 39, so that the suction in the body of the tube 2 opens the valve 37 and draws the cartridge along, air being admitted at the rear through small holes 35. After the cartridge has passed the valve 40, the rod 56 acts on the slotted link 58 and opens the valve 40 to admit air freely behind the cartridge. The pawl 67 is afterwards released and the valve 37 closed, and the lever 54 then raised to reverse the cocks 50, 47, thus closing also the valve 36. When the valve 69 is released from the lug 74, the pressures in the top and bottom of the cylinder 55 are equalized through the small bye-pass 72, so that the rod 56 falls and closes the valve 40. The byepass 72 is adjusted so that the valve 40 closes only after the cartridge has passed out of the first section of the tube, which is then again opened to the suction pipe. When approaching the end of the first section, the cartridge passes and raises a lever 80, Fig. 5, which is pivoted in a housing 98 on the tube 2, so that a stop lever 97 is raised clear of a sliding rod 96. A spring 94 then oscillates a lever 92 to slide a cam-plate 90 from one end to the other of its case, the final effect being that the cylindrical suction valve is rotated by an arm 88 on its spindle, and the connection between the tube 2 and the suction pipe 1 closed. The suction valve is of the cylindrical balanced type, and consists of two separate cylindrical valves on one spindle within a casing 81, which is under the camplate 90 and above the pipe 1, and is fitted at the central part with the passage 86 to the tube 2. The forward section is closed by a transverse and inclined valve 75, Fig. 6, turning on a pivot 76 and balanced by a spring 77 so that, if not already open, it may be raised easily either by the advancing cartridge or by the slightly. compressed air in front of it. After entering the second section, the cartridge operates a depending lever 107 and thereby also, by reason of the levers 104, 103 and link 105, the air valve 102 on the bottom of a cylinder 101 similar to the cylinder 55 already described. The piston 100 in rising then opens an air valve 78, which admits air behind the cartridge to foice it forwards and also to close the valve 75. At the same time, the piston acts through a lever 110 on the rod 91, Figs. 1 and.5, thereby re-opening the first section to the suction pipe and re-setting the mechanism of the suction valve. The valve 102 is afterwards closed by a lug 109 on the pistonrod, and the bye-pass 72 acts, as in the case of the cylinder 55, to close the valve 78 after a short interval. As the vacuum is re-established in the first section immediately the cartridge passes out of it, a second cartridge can then be transmitted. The delivery end of the tube 2 is connected to the pipe 1 by a small pipe 114, Fig. 1, and is fitted with a valve which is somewhat similar to the valve 75 and which opens under the slight compression of the air in front of the advancing cartridge. The cartridge is expelled into an inclined terminal piece 117 provided with a spring dash-pot which returns the cartridge on to a table 116. In the arrangements shown in Fig. 1, two pumps 3,4 are provided, one for neutralizing the effect of leakages in the system and the other for maintaining the vacuum necessary when the system is in use. The latter or main pump 3 is driven from the motor 5 only when the pulley 9 is clutched to its shaft. The clutch provided consists of a shoe 13, Fig. 8, placed between a flange 11 on the pulley 9 and a boss 12 on the shaft 10 with a coiled flexible pipe 14 underneath it. The pipe 14 is connected through a stuffing-box 16 with a fixed tube 18 fitted with piston valves 19, 20 to control the connection of the pipe .14 to pressure water inlet and outlet pipes 21, 22. The stem 24 of the valves 19, 20 is secured to, and passes through, a disc 23 in a casing 25 which is connected on opposite sides to the air and to the suction pipe 1, Fig. 1. The disc 23 is nor. mally forced into the position shown in Fig. 8 by a spring 30, so that pressure water enters the pipe 14, expanding it to clutch the pulley 9 and shaft 10 together. When, by the operation of the pump 3, the pressure in the suction pipe 1 falls to the desired amount, the disc 23 is drawn back to open the pipe 14 to the outlet 22 and so to stop the pump. The pressure at which this action occurs is regulated by means of a screwed hollow plug 29 acting on the spring 30. Small fluctuations are prevented by means of an adjustably-weighted lever 31 from affecting the disc 23.