IMPROVEMENTS IN APPARATUS FOR CASTING STEREOTYPE PLATES
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Richard Bagnall Reed at the Office
of the Commissioners of Patents on the 2nd March 1880.
RICHARD BAGNALL REED, of Newcastle on Tyne, in the County of Northumber-
land. 'IMPROVEMENTS IN APPARATUS FOR CASTING STEREOTYPE PLATES."
"
The object of this Invention is to provide an apparatus for casting stereotype
plates for cylinder letter press printing machines in a more expeditious manner
than heretofore.
The apparatus consists of a semi-cylindrical support for the matrix of the plate,
and which is mounted in a suitable framework or stand. To this support is hinged
or otherwise suitably connected a hollow metal cylinder having a radius equal to
the concave surface of the plate it is desired to cast, and this cylinder forms the bed
on which the plate is cast.
A segment of this cylinder is cut out and it is connected at its lower end to the
main body of the cylinder by hinges which will admit of its opening outwards a
short distance. This segment piece is provided with a rib which runs longi-
tudinally of the cylinder, and two short ribs extending transversely of the cylinder
from the longitudinal rib to the upper edge of the segment piece. These ribs
together with a flange on the support form when placed together a runner into
which the molten metal for casting the stereoplate is poured.
*
"
When taking a cast the paper matrix is placed in the support and semicircular
end pieces or strips, whose total depth is equal to the thickness of the matrix and
the plate to be cast, are placed between and near the ends of the support and the
cylinder to form ends to the mould; the segment piece of the cylinder is then
closed down and the cylinder turned over on its hinges, until it fits against the end
pieces when it is clamped to the support. The molten metal is then poured in from
the top, and when it has been allowed to cool for a few minutes the clamps are
removed, and the cylinder carrying the stereoplate is turned back in order that the
'sprue" may be removed before the plate is taken from the cylinder to the
printing press.
.66.
The removal of the "sprue" may be effected by means of a rotary saw which is
run across it in the usual manner.
In order however to entirely sever the sprue from the plate it is necessary
that a portion of the cylinder should be removed to form a passage for the saw
to pass along, and this without removing the support for the sprue. This
removal of a portion of the cylinder is effected by turning back on its hinges
[Prine 231

page_text: the segment piece a sufficient distance, say a quarter of an inch, to allow the saw
to pass along the space thus left.
When the sprue is removed the plate is lifted from the mould, trimmed, and
placed upon the printing cylinder without further delay.
As a modification of this arrangement the segment piece may be carried by arms
mounted loosely on the axis of the cylinder, so that it may be slidden back by
means of a cam or excentric the required distance to make an opening or slot in the
cylinder for the passage of the saw.
In this case however the circumferential width of the segment piece must be less
than the gap made in the periphery of the cylinder to receive it, so that sufficient
space may be left for the segment piece to slide back the required distance.
Or the segment piece may be mounted on curved guides suitably carried for the
purpose, and the sliding motion may be given in any convenient manner to the
segment piece.