Patent GB-759132-A (GB)
Title: Improvements in and relating to coating or enrobing machines
IPC: B05C5/00
Filed: 1952-01-19
Abstract: <PICT:0759132/III/1> <PICT:0759132/III/2> <PICT:0759132/III/3> In a machine for coating articles with molten or plastic substances, of the kind in which the articles under treatment are carried on a moving conveyer through a falling curtain of the coating substance, the curtain issues from a slot provided at the base of a hopper and in the bottom of a groove which has seated therein an angularly-adjustable valve of half-round section, which, in one position, has its flat face flush with the hopper base, and in other positions has an edge co-operating with an edge of the slot to control the effective width of the latter, and hence directly to regulate the rate of discharge of the hopper. As illustrated, articles to be coated are carried on a moving conveyer 10, preferably of stainless steel wire mesh, beneath a hopper 11 fed with molten chocolate or other coating substance from a fishtail nozzle 13.  The hopper 11, also of stainless steel, is mounted transversely of the conveyer 10, and its height may be adjusted by a handle 36, through leadscrews 32, which are interconnected as by a chain 37 and sprockets 38, and act on nuts formed in blocks 27 on the sides 11a of the hopper 11.  The latter projects beyond both lateral edges of the conveyer 10 and has partitions 14 acting as overflow weirs and dependinng at 15 to direct overflowing material clear of the conveyer 10.  The bottom of the hopper 11 is formed by a thick plate 16 (Fig. 3) in whose upper face are formed two parallel longitudinal grooves 17 of semicircular cross-section, at the bottom of each of which is a vertical slot 18.  Valves 20, having the same cross-sectional shape and size as the grooves 17, lie in the latter; the end portions of the valves have cylindrical portions fitted in bearings, and are provided with handles 24 for controlling the rate of flow of the coating material forming the curtain 25.  The intervening parts of the valves 20 are supported at intervals by recessed members 21, the inner surfaces of the recesses being engaged by pins 23 on the valves.  The hopper may be provided with a wire-mesh filter 26. Below the conveyer is a rectangular surge tray 39, pivoted at its front end about an axis 40, the height of the rear end being adjustable by nuts 42 on screws 41.  Two horizontal rollers 441 and 442 are journalled in fixed bearings in the machine frame for rotation in the tray 39, the roller 441 being continuously rotated and co-operating with a doctor plate 45, carried on a flat horizontal surge plate 46; the heights of both plates are adjustable by screws 47.  The rotation of the roller 441 causes an upsurge 52 of the coating substance across the top of the plate 46 and through the conveyer 10, to coat the lower surfaces of the articles thereon. The roller 442 may rotate in the same direction as the roller 441, or be contra-rotated to increase the height of the upsurge 52.  The tray 39 is provided with an overflow weir 50, which is hinged, and, when fully lowered, allows the tray to empty.  Specification 663,049 [Group VI] is referred to.