Patent GB-803333-A (GB)
Title: Improvements in and relating to means for controlling the movements of articles on conveyors
IPC: B65G47/68
Filed: 1956-03-22
Abstract: 803,333. Endless conveyers. ROWE, A. E. March 20, 1957 [March 22, 1956], No. 8916/56. Class 78 (1). In an endless conveyer system wherein conveyers A, B meet at a junction to form a single conveyer means is provided for preventing collisions between articles approaching the junction comprising a feeler 10 in each of the conveyers A, B, a withdrawable stop member 3 in each conveyer, and a control apparatus so relating these elements that when the feeler in one conveyer is operated the stop member in the other conveyer is made operative to arrest the flow of articles thereon unless the feeler in the other conveyer is already operative. Means is also provided whereby if both feelers are operated simultaneously by articles the stop member in a selected one of the conveyers is made operative. Each conveyer consists of a pair of endless chains al, a2, b1, b2 respectively, each stop member being disposed between the respective pair of chains and each feeler being disposed on the outside of one of the chains of the respective pair. Each feeler is a pivoted lever which, when engaged by an article, e.g. a box, is caused to open a pneumatic valve, Fig. 4, or close a switch 15, Fig. 5, and each stop member is a plate adapted to be projected by a pneumatic cylinder 5 when air is supplied to it. In the all pneumatic arrangement, Fig. 4, the valves operated by the feelers 10 are arranged to supply air to respective ends of a shuttle valve 9 to move the piston of the shuttle valve to one end or the other and so cause the supply of air via the shuttle valve through line 7 or 8 to one or other of the cylinders 5, the unoperated cylinder 5 being exhausted through the shuttle valve. Restrictor devices 12 are inserted in the lines 7 and 8 and are designed to allow easy flow to the cylinder 5 but restricted flow away from the cylinders. In addition, a further piston-controlled valve 13 is disposed in the line between one of the feeler-operated valves and the respective end of the shuttle valve, the piston of valve 13 being normally held in a position in which air is allowed to pass through it by pressure derived from one of the lines 7 or 8 through restrictor devices 15. The arrangement is such that if both feelers are simultaneously actuated by articles causing the shuttle valve to become temporarily stalled in an intermediate position, both lines 7, 8 are exhausted and air leaks away from the piston of valve 13 causing a spring to move this piston into a position blocking the supply of air to that end of the shuttle valve with which it is associated, so that the shuttle valve moves to the other end position. In the electro-pneumatic system of Fig. 5, the valves operated by feelers 10 are replaced by the switches 15 referred to above, the piston of the shuttle valve is arranged to be moved to either end by respective solenoids 14 energized by operation of the switches 15, and the valve 13 is replaced by a pistoncontrolled switch 13<SP>1</SP> arranged in series with one of the switches 15. This arrangement operates similarly to that of Fig. 4.