GB1441099A - Control system for repetitive processes - Google Patents

Abstract

1441099 Controls for glass blowing machines HAWKER SIDDELEY DYNAMICS ENG Ltd 26 June 1973 [27 June 1972] 19519/72 Heading C1M [Also in Division G3] In the automatic control of repeated cycles of a glass forming machine 1 the occurrence of events within each cycle is controlled via comparator 9, comparing the content of a counter 8; advanced by shaped pulses derived from transducer 4 detecting a plurality of marker pulses for each machine cycle and actuated in dependence on the angle of machine driven shaft 2; with the content of memory 9, containing, for each specific machine function a-n to be addressed, the count for which such function is to be switched on, or off. Under control of unit 11, every location of memory 10 is interrogated for each step of counter 8, an output address bus connected to stages 12a-12n ensuring that any comparator coincidence signal enables the addressed output stage, controlling a corresponding valve, pneumatic, hydraulic, or electromagnetic actuator, or electric motor. At the completion of each machine cycle, a shaped pulse from transducer 5 actuated once per complete cycle in dependence on the angle of machine driven shaft 3 resets counter 8 for the next cycle. Transducers may be of electromagnetic impulse or proximity or photo-electric type. Memory 10 may be of read-only preprogrammed type, using sets of switches to store the counts at which each machine function is to be switched on, or off, or a readwrite memory may receive data from keyboard 14 via unit 16, entered data being displayed by unit 15. New data, or data modifications may enter on line 17, from a computer, or punched or magnetic tape (cartridge, cassette, or reel), or a magnetic drum or disc store, or as feedback derived from machine sensors to constitute a retroactive arrangement, or from an operator inspecting the machine. Counter 8 may be in two parts each driven, in parallel, a comparator between the two parts being provided, and providing inhibiting and warning signals if coincidence is absent. Glass forming machine.-The machine 1 produces sets of "gobs" of given size, which are separated and each blown in two moulds, each "gob" being inverted between blowing operations, there being a plurality of moulds, and the product being ejected onto a conveyer belt. Control may be of "gob" weight, or hardness, blown size of glass, or physical imperfections.