Patent GB-1241141-A (GB)
Title: Improvements in or relating to pneumatic shuttle-conveying systems
IPC: B65G51/20
Filed: 1969-10-02
Abstract: 1,241,141. Pneumatic shuttle conveyers. SIEMENS A.G. 2 Oct., 1969, No. 48504/69. Heading B8A. In a pneumatic shuttle conveying system having stations RS2 to RS8 arranged along a travel tube F between terminal stations RS 1 and RS9, each intermediate station includes a delay tube VR2 to VR8 for receiving or despatching a shuttle from or to the system, the tubes VR2 to VR8 each being inclined downwardly from the tube F at switchpoints W2 to W8. The delay tubes VR2 to VR8 couple the travel tube switchpoints to despatch devices S2 to S8 for receiving or despatching shuttles. The delay tubes VR1-VR9 at the termini stations are provided with values Va and Vb operable to open the system to atmosphere, the despatch devices S1 and S9 for these stations extending directly from the ends of the travel tube F. In a first condition of operation when a shuttle is selected to be transferred from station RS5 to station RS8, for example, the despatch device 55 comprising a slidable, sealable sleeve extension of the delay tube VR5 and incorporating a buffer mounted electromagnetic valve V5 for opening the device to atmosphere, is opened to insert a shuttle, and then closed, and a control ZS is supplied with a shuttle destination signal. Once the tube F is clear, the control ZS sets switch tongues of the switchpoints W5 and W8 to provide communication between the delay tubes VR5 and VR8 and the tube F, causes valves Va and Vb to close and valve V5 to open, and switches a blower G in the tube F into a sucking operation whereby the shuttle is sucked into the tube F thereby operating a photo-electric contact fK5 causing the valve V5 to close and the valve Va to open. A contact fg is operated by the shuttle as it approaches the blower G to change the operation thereof to that of blowing and to cause the valve Va to close and the valve Vb to open, whereupon the shuttle is conveyed into the delay tube VR8 where it gravitates against a cushion of air, for removal. The resetting of the switch tongues to their original positions is effected as the shuttle -operates the contacts fK5 and fK8 at the stations RS5 and RS8. In a second condition of operation when a shuttle is to be transferred from station RS2 to station RS5, for example, the shuttle is sucked into and along the tube F as before but the switch torque at station RS5 permits the shuttle to pass the delay tube VR5 until it operates the contact fK5 whereby the blower G is switched off and the switch torque moved to direct the shuttle into the delay tube VR5 as it gravitates backwards. In a third condition of operation when a shuttle is to be transferred from station RS7 to station RS8, for example, the shuttle is sucked into the tube F as before, but upon operation of the contact fK7 the blower is switched into a blowing condition, the switch torque at station RS7 is moved to permit the shuttle to pass back over the delay tube VR7 and along into the delay tube VR8. Delay tubes at stations between which a lot of shuttle traffic is expected may be inclined towards each other whereby the shuttle doesn't have to traverse the same switchpoint twice during transfer.