GB1174908A - Improvements in and relating to Manufacture of Articles of Food - Google Patents

Abstract

1,174,908. Moulding pie lids. J. LYONS & CO. Ltd. 19 March, 1968 [20 Dec., 1966], No. 56945/66. Heading B5A. In a pie lidding apparatus, a dough piece prepared by pressing into a recessed roller by a doctor or scraper, or by means of an adjustable stroke piston apparatus, is pressed between surfaces of an upper plunger and a lower stationary platen with one or other of the surfaces being heated to a higher temperature whereby, after separation of the surfaces, the moulded dough piece is retained on the cooler surface wherefrom it is applied to a lidless container containing filling and with or without a pastry lining. The plunger and platen are provided with air passages, and may have porous metal surfaces, whereby suction is prevented from building up during the separation of the surfaces and which separating operation may be supplemented by the application of positive or negative fluid pressure through the passages. The moulded dough, if retained on the plunger, may be applied to the pie by relative downward movement of the plunger with respect to a downwardly spring loaded skirt, defining part of the moulding space, and released from the plunger by air pressure. The plunger with the lid to be applied may be positioned with respect to the pie by delivering the pies to the plunger on a conveyer or rotating turret, or the plunger may alternatively be displaced thereto. Alternatively, the moulded dough may be retained on the cooler surface of the platen which is then pivoted or turned through 180 degrees to apply the lid, with release therefrom effected by air pressure. In one form of apparatus, metal foil dishes 50 are intermitently conveyed to a pie lidding position, within apertures 50 of carriers. e.g. 52, carried by a pair of endless chains 53; the chains in common with all parts of the apparatus being driven from a main shaft 60. Dough portioning mechanism 72 comprises a hopper 73 wherefrom a reciprocating knife and plunger arrangement 75, 77, driven by a lever arrangement from a cam-shaft 65, delivers dough into the cylinder 81 of a member 82 which then rotates through 90 degrees, to deposit the dough on to a heated platen 117 by the action of a piston 83, actuated by a reciprocable cross-head member 89;-the members 89 and 82 being driven by a lever arrangement from a cam-shaft 93. A series of platens 117-124 are mounted for intermittent movement in an endless path, upon carriages 125 which are driven by a chain 128 and are movable along a guide channel 127 provided with conductor rails whereby current is supplied, via a thermostat, to platen heating elements. The dough is moulded to the lid on a platen, e.g. 119, by a plunger 132, reciprocated by an eccentric drive from a shaft 135, which is provided with a spring biased skirt and with air pressure supply means and is heated to a higher temperature than platen 119 to facilitate dough release. In the lidding position, a pie carrier 144 -is raised from chains 53 to urge the rim of the pie against the lid, by a beam (145), Fig. 26, not shown, provided with suction gripping nozzles (126) whereby, with the assistance of pressure air supplied to the platen 121, via a pipe (183) movable with the beam (145), the lidded pie is separated from the platen 121 on descent of the beam (145). Pins (181) are provided on the beam (145) for locating the pie carrier 144 and the beam (145) is reciprocated by a lever arrangement from cam-shaft 135 and guided by carriages (166) which run in rails (168). The plunger (132), Fig. 27, not shown, is provided with an intermittently actuated air pressure supply via passages (139, 207) and a plurality of poppet valves at the plunger face to effect release of the moulded dough, and with an independent air supply at constant pressure, via passages (217, 216) to a plenum 209 within relatively movable portions of the plunger to provide a resilient cushion against over-weight dough pieces. The air cushion is replacable by a spring or foam material. Shaft 135 is driven froma main shaft 60 input gear-box which is also drivingly connected to sprocket 131 of chain 128, via an intermittent drive gear-box.