Patent GB-190303721-A (GB)
Title: Improvements in Casting Machines.
Inventor: MCADAMS WILLIAM ALBERT
Filed: 1903-02-17
Granted: 1903-08-13
Abstract: 3721. McAdams, W. A., and McDavitt, J. J. Feb. 17. Casting.-Relates to machines for casting aluminium alloys and other metals into bars or other forms. Fig. 2 shows a longitudinal section, and Fig. 3 a plan of a machine. Shallow pans 7, 8 are supported on pedestals, and have bolted to them brackets on which the other parts of the machine rest. The metal is fed in the form of bars 20, into the crucible 13, which is made of Dinas brick or other refractory material, and is suitably lined. The cover is made in sections, which are free to lift in event of excessive pressure. The openings 14 &c., through which the bars are fed, have notches in their ends to guide the bars, spaces being left at their sides for the escape of the hot gases. The outer metal casing 47 has a refractory lining, provided with notched ribs to form a series of communicating firechambers. A pocket 50, below each chamber, communicates with a cylinder 52, Fig. 5, through which the heating-jet from the burner 53 passes. Each cylinder and burner is supported on an arm 62, which can be swung down about a pivot 63, to allow the jet to be lit. A hydrocarbon is supplied to the burners from a tank 70, by means of air pressure. The height of the metal in the crucible is regulated by a spout 25, which is adjustable vertically by rack-and-pinion gear, and can be lowered to empty the crucible. From the spout, the metal falls on to a shoot, which delivers it into a mould 30 formed in a block 29. This block contains a number of moulds, which are filled in succession by moving the block endways on the supporting-bracket 36. The front of each mould is formed by a cover 38, hinged to links, so that it can be lifted, and swung away, by means of a handle 40. Extractors 44 with noses projecting into the moulds withdraw the castings, which then drop. A cooling-liquid is circulated through the block and cover from a tank 34. From the crucible the molten metal flows, past a valve 73, into a pressure chamber 71, constructed and heated in a similar manner to the crucible. This chamber has a cover provided with a flange fitting the interior of the chamber. An angle-bar fits against the outside of the chamber and the lower face of the cover. The valve is raised from its seat by a bell crank actuated by a rod 89 and other gearing from an eccentric on the driving-shaft 138. The valve can be lifted into the dome 83 by means of a rod 84. It is sealed by a pocket of molten metal. An observation tube 91 is provided in the top of the dome, which communicates with the high-pressure reservoir 95, through a valve-casing 93, Fig. 11. The casing communicates by means of a pipe 92 with the dome, and by means of a pipe 94 with the reservoir. It contains two slotted tubular valves, connected by a rod 153, and operated by an eccentric through a rod 156 and a pair of springs. In the position of the valves shown, the pressure chamber is in communication with the atmosphere, and is being filled from the crucible. After the valve 73 has been closed, the valves 146, 151 are raised, cutting off the chamber 71 from the atmosphere, and admitting air from the pipe 94. The metal is thus forced past the valve 103, Fig. 2, into the chamber 99, and thence into the mould or die 118, which is surrounded by a chamber 119 in communication with the cooling-tank. The chamber 99 is constructed and heated in a similar way to the crucible, and communicates with the low-pressure air reservoir by a pipe 110 provided with a safety-valve. As the bar leaves the die 118, it is gripped by rollers 123, 124 which can be driven at any required speed by means of bevel and change gearing. This gearing is controlled by a hand-lever 140 and clutch. Fig 14 shows a device for moulding under pressure. From the crucible 171, the metal is delivered past the valve 173 into the chamber 172 and, by means of pressure supplied through the pipe 174, is forced upwards through the delivery spout 175 into the receiving-spout attached to the mould, which may be one of several carried by a revolving table. A sharp edge 179 cuts off the metal when the pressure in the chamber 172 is withdrawn. Fluid under pressure is supplied by a pipe 180 to the mould, to compress the metal as it is poured in. Spring-actuated jaws 182, 183, pulled apart by a treadle, make a tight joint between the receiving and delivery spouts.