The present practice in making metal sheets is to cast ingots or slabs
and then reduce these by repeated rollings and reheating. Attempts
have been previously made to produce sheets directly from molten metal
by pouring the metal: (1) between two revolving rollers; or (2)
between a revolving wheel and the surface of an inclosing fixed
semicircular segment. By these means none but very thin plates could
be satisfactorily produced. In this invention by C.M. Pielsticker,
London, the machinery consists of a large receiving roller of 5 ft.
diameter more or less, and of a length equal to that of the plate to
be produced. With this are combined small forming rollers arranged in
succession part way round the periphery of the large roller, and
revolving at the same rate as the large roller. The rollers can be
cooled by a current of water circulating through them. The molten
metal flows on to the surface of the large roller and is prevented
from escaping sideways by flanges with which the large roller is
provided. These flanges embrace the small rollers and are of a depth
greater than that of the thickest plate which it is proposed to roll.
The distance between the large roller and the small rollers can be
adjusted according to the desired thickness of the plate. When dealing
with metals of high melting point, such as steel, the first small
roller is made of refractory material and is heated from inside by the
flame of a blow pipe. The rollers are coated with plumbago or other
material to prevent adhesion to the molten metal. In the case of
metals of high melting point the machine is fed direct from a furnace
divided into two compartments by a wall or bridge in which is a
stopper which can be operated so as to regulate the flow of metal.
When applied to forming sheets of glass, the rollers should be warmed
by a blow pipe flame as above described, and the sheet of glass
stretched and annealed as it leaves the last roller.
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