Patent GB-1235470-A (GB)
Title: Improvements in or relating to flat glass manufacturing apparatus
IPC: C03B18/14
Filed: 1967-11-09
Abstract: 1,235,470. Dispensing apparatus. PILKING- TON BROS. Ltd., and J. MATHER. 21 Aug., 1968 [9 Nov., 1967], No. 51145/67. Heading B8S. [Also in Division C1] An apparatus for dispensing metal pellets, .e.g lead shot, individually into a supply duct 52 connected to a feed head 41. (Fig. 4), which feeds the material of the pellets when molten into a body of molten metal 36 in contact with flat glass, comprises a marshalling hopper 46-47 of width just greater than the diameter of the pellets and having an outlet channel 50 through which the pellets fall in single file, a supply duct 51 (Fig. 3) communicating with the channel 50, a detent 53 in the supply duct which holds back the pellets and an ejector 57 mounted relative to the supply duct where it is connected to the channel and operable by driving means to force one pellet at a time past the detent into the supply duct. The supply duct 51 is extended as a bore beyond the channel 50 and through one side of the hopper, the ejector 53 being mounted in this bore. The ejector is connected to a plate 58 externally of the hopper and to this plate is also connected a disturbance rod 63 extending through a bore 64 into the main body of the pellets. The plate 58 is connected to a spring-loaded piston and cylinder arrangement 60-62 which in the inoperative position with draws the ejector along its bore away from the detent. The cylinder 61 is operated by a signal from a solenoid 66 which is actuated by a control signal related to the lead content of the  molten body 36. The supply duct 52 connects with a graphite lined steel feed pipe 40 leading to a graphite feed head 41. The feed head (Fig. 4) has a central bore portion 72, the lower end of which terminates in a downwardly extending portion 73 of lesser diameter from a shoulder 74. A plug 75 seats on shoulder 74 and has a central bore 76 communicating with portion 73, the upper face of the plug 75 being a funnel-shaped inlet 77. The feed head has a protruding nose 82 having an upwardly sloping lower surface into which is fitted a graphite spout 42. The spout communicates with a bore 85 extending upwardly through the nose to the upper surface 86 where it meets an upwardly inclined bore 87 extending from said upper surface 86 to a position near the bottom of portion 73. The bores 85, 87 meet and define a knife edge which in turn defines the level of molten metal to form a reservoir 89. Thus on actuation of the dispenser 45 a lead shot is forced down supply tubes 52, 40 into the feed head 41. It drops in the funnel 77 and if too big to fall down bore 76 into reservoir 89 remains there until it melts and gradually runs into the reservoir. This causes the level to rise and allows molten metal to pass through spout 42 into a recess 43 in the upper surface of an electrode 31 to which a main body 36 of molten material clings and is in contact with the developed ribbon of glass 32. Movement of pellets down supply duct 52 may be assisted by a flow of purging gas through the duct, which gas exhausts through apertures 95, and aperture 81 in the cap 80 of feed head 41 (Fig. 4).