Automatic press

Abstract

Abstract The method provides matched molds in superimposed relation, cyclically reciprocating vertically each of said molds relative to the other, to first mold a product in a continuous web of heated thermo-plastic material fed cyclically between said molds, halting each cycle just short of its reaching the point of maximum proximity between said molds to allow the material adjacent the periphery of said product to cool prior to performing the trim step, starting the next following cycle with the trim step, the latter being accomplished by continuing the approach of said molds to the point of their maximum proximity, said product being left connected to the web by easily broken tabs and punching the product from the web at a stacking station during a succeeding cycle. The apparatus embodies a double action automatic press including parallel vertical side frames rigidly united with each other and with a tripod supported base. A pair of massive vertical guide posts fixed at upper and lower ends to inner faces of said frames, vertically guide upper and lower tooling mounting platens, each platen being connected by four adjustable links to arms on one of two pair of rocker shafts, one such pair being above the upper platen, the other pair being below the lower platen. Outside one side frame, short arms are fixed on the upper pair of rocker shafts and double armed bell cranks are fixed on the lower pair of rocker shafts, each of the bell cranks having a long arm and a short arm. A pair of long links connect upper and lower outside short arms and a third link connects said long arms. A pitman connects one of said long bell crank arms to a crank arm fixed on one end of a transversely journaled crank shaft at the forward end of the press. A base mounted constant speed motor is connected through a variable speed transmission and an electro-air controlled clutch brake mechanism to a reduction gear box which is interposed in a gap in said crank shaft and directly drives the latter. Each revolution of the drive shaft accomplishes one production cycle of the press. A separate control device determines at what point in the production each cycle ends to provide a cooling "dwell" between cycles so that the trim step takes place at the beginning of each cycle, thereby improving the product. A cyclic web feeder and heater is provided on and driven by the press. The tooling employed in the press leaves the product lightly connected with the scrap of the web following each trimming step by several oppositely disposed transfer tabs which may readily be broken by a punching operation when the product arrives at a stacking station. The press embodies and automatically drives a product punch for accomplishing this function. A product stack conveyor receives products thus punched from the web and automatically discharges product stacks of predetermined quantity. A scrap chopper disposes of the scrap left in the web. The press also includes separate means manually operable while the press is running to vary the time period of the cooling dwell and also to vary the distance, short of reaching the point of maximum proximity between the platens, at which each operating cycle concludes.

Inventors

• 👤 Jere F Irwin

Bibliographic Details