Molding machine monitoring system

Claim 1

A monitoring system for detecting molded material in a molding machine having two platens, relatively movable between a first position for receiving molding material in die cavities formed between said platens and a second spaced-apart position in which said platens should carry no molded material, one of said platens including a plurality of die recesses, each recess having a first condition in which the recess is free from molded material and a second condition in which said recess has molded material disposed therein, said system comprising a television camera for sensing said one platen and providing a video signal output representative of all of said plurality of die recesses of said one platen, display means at a position spaced from said molding machine including a screen and means responsive to said video signal for providing a visual display representative of said die recesses on said screen, an array of photocells, each corresponding to a die recess and being disposed in fixed relation relative to said screen to sense the condition of the image of the corresponding recess when said platens are in said second position, and having first and second outputs corresponding, respectively, to said first and second conditions, and an electrical circuit having first switch means, said first switch means having a closed position permitting said machine to operate and an open position in which said machine does not operate, said circuit being arranged to open said first switch means when one of said photocells has a second output indicating the presence of molded material in a monitored die recess and second switch means arranged to return said first switch means to said closed position when all of said photocells have their first outputs.