Improvements in or relating to the Production of Electrotype Plates for Printing Purposes.
Year: 1893

page_text: Date of Application, 28th Dec., 1893
Complete Specification Left, 28th Sept., 1894-Accepted, 24th Nov., 1894
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Production of Electrotype
Plates for Printing Purposes.
I, RICHARD JOHN LATIMER, of 157 St. Andrews Road, Higham Hill,
Walthamstow, in the County of Essex, Electrotyper and Stereotyper, do hereby
declare the nature of this invention to be as follows:-
This invention relates to a new or improved method of backing-up electrotype
shells for the production of electrotype plates for printing purposes, whereby such
plates can be produced in an efficient manner in much less time and at less cost
than with the usual method, the operations of turning in a lathe and bringing-up
on a polished steel surface being dispensed with.
According thereto the copper shell which forms the foundation, and also the
face of the electrotype plate is first covered on the back or pink side with a
solution of chloride of zinc and tin foil or solder. The shell with the tin foil, or
solder, as the case may be, is then put into an open iron pan which is placed upon
the surface of molten metal where it is allowed to remain until the tin foil or
solder melts and covers the pink side of the shell so as to unite therewith. The
shell is then removed from the pan and washed with warm water in order to free it
from any dirty matter that may be adhering to the tinned side. A piece of sheet
material such as strong paper, brown will do, is now attached, it may be by pasting,
to one end of the copper shell on the tinned side, to act as a guide when pouring
the molten backing metal into the casting box, or a piece of thin sheet metal such
as sheet iron bent over the top of the box with one end resting over the top of the
shell will answer the same purpose, but greater care must then be used in pouring
the metal into the casting box, otherwise some of it may find its way on to the
face of the shell. The tinned shell is then again covered with solution of zinc and
dried. If cut work is to be backed up or the shell has holes in it, the face of the shell
should be wiped over with a soft dry rag whilst it is warm so as to free it as
far as possible from the wax thereon, after which a little blacklead may be lightly
rubbed over it.
The tin foil used should contain a large proportion of tin, say about equal parts
of tin & lead.
The shell thus prepared is then ready to be placed in the casting box which
should be previously heated to a temperature somewhat higher than the melting
point of the tin foil or solder used, say to about 600° F. The prepared shell is
placed in the casting box face downwards, a set of grooved gauges being laid on
the bottom of the said box so as to overlap the two sides and oue end of the shell
and permit the same to freely expand and contract, the other end being left free
with the paper or other attachment hanging out at the front end of the casting box
and a piece of suitable material, such as dry cardboard, is placed over both gauges
and copper shell in order to prevent rapid cooling of the backing metal when
poured into the box. The box is then closed and placed in an upright position
and the molten backing metal poured into it between the gauges up to within say
about one inch of top of the box, and after allowing the metal to set, the box is
turned down and the plate removed and cooled under hand screw pressure which
may be done in a similar box to the casting box.
In this way a copper shell can be backed up in a few minutes and the resulting
electrotype plate is practically perfect on the face and equal in that respect to the
type or cut from which the mould for the electro was taken. The plate may be

page_text: cast to any desired thickness and will usually only require one cut or shave in the
planing machine to give it a smooth back suitable for "impression" in printing.
Dated this 28th day of December 1893.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.
COMPLETE SPECIFICATION.
Improvements in or relating to the Production of Electrotype
Plates for Printing Purposes.
I, RICHARD JOHN LATIMER, of 157 St. Andrews Road, Higham Hill,
Walthamstow, in the County of Essex, Electrotyper and Stereotyper, do hereby
declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement :-
This invention relates to a new or improved method of backing-up electrotype
shells for the production of electrotype plates for printing purposes, whereby such
plates can be produced in an efficient manner in much less time and at less cost
than with the usual method, the operations of turning in a lathe and bringing-up
on a polished steel surface being dispensed with.
According thereto, the copper shell which forms the foundation, and also the
face, of the electrotype plate, is, after having its edges trimmed, first covered, as
usual, on the back or pink side with a solution of chloride of zinc and tin foil or
solder.
The tin foil used should contain a large proportion of tin, say about equal parts
of tin and lead. The shell with the tin foil, or solder, as the case may be, is then
put into an open iron pau which is placed upon the surface of molten metal, in the
ordinary way, where it is allowed to remain until the tin foil or solder melts and
covers the pink side of the shell so as to unite therewith. The shell may, however,
be heated for this purpose in any other suitable manner.
The shell is then
removed from the pan and washed with warm water in order to free it from any
dirty matter that may be adhering to the tinned side. This washing is important
as it enables the backing metal that is subsequently applied, to be in intimate
contact with the back of the shell over the whole of the surface thereof. A piece
of shect material such as strong paper, brown will do, is now attached, it may be
by pasting, to one end of the copper shell on the tinned side, to act as a guide
when pouring the molten backing metal into the casting box, and prevent the
backing metal passing to the face of the shell, or a piece of thin sheet metal,
such as sheet iron, bent over the top of the box with one end resting over the
top of the shell will answer the same purpose, but greater care must then be used
in pouring the metal into the casting box, otherwise some of it may find its way
on to the face of the shell. The tinned shell is then again covered with a flux
such as a solution of chloride of zinc, and dried. The face of the shell is now
brushed over with blacklead; but if cut work is to be backed up, or the shell has
holes in it, the face of the shell should be first wiped over with a soft dry rag
whilst it is warm so as to free it as far as possible from the wax thereon.
The shell thus prepared is then ready to be placed in the casting box, which
may be of any suitable kind and should be previously heated to a temperature
somewhat higher than the melting point of the tin foil or solder used, say to
between 6000 and 700° F. The casting box may conveniently consist of two flat
plates 1 and 2, of iron having smooth inner faces, as shown in longitudinal and cross
section respectively in Figs. 1 & 2 of the accompanying drawings, these plates
being connected together at one end by a pin and slot connection like the plates

page_text: composing an ordinary casting box for stereos, and secured together for use by
suitable clamps. The prepared shell 3 is placed in the casting box face
downwards, a set of grooved guides or gauges 4, of rabetted form in cross
section, being laid on the bottom of the said box so as to overlap the two sides
and one end of the shell to a small extent as shown, and permit the same to freely
expand and contract, the other or outer end being left free with the paper 5 or
other attachment thereon hanging out at the front end of the casting box. The
portions 4ª of the gauges 4 which overlap the shell 3 should touch or nearly touch
the shell but not bear tightly against it so that whilst the shell is free to expand
there will be little or no liability of the backing metal passing between it and the
guides and thence to the face side. As the gauges will be put in place only just
before the casting is to be effected, they will be cooler than the casting box and
will therefore act to cool and solidify any of the backing metal that may enter
between them and the shell. When the guides are put in place, a piece 6 of
suitable material, such as dry cardboard, that is a bad conductor of heat, is placed
over the gauges and copper shell in order to prevent rapid cooling of the backing
metal when poured into the casting box. The piece of cardboard or other material
should be previously brushed over, on the side that is to be next the shell, with a sub-
stance such as chalk or preferably blacklead, in order to render it available for a
larger number of backing-operations and to enable the operator to detach it more
easily from the backing. The box is then closed and placed in an upright position
and the molten backing metal poured into it between the gauges up to within say
about one inch of the top of the box, and after allowing the metal to set, the box is
turned down and the plate removed and cooled under slight pressure, which may be
done in a similar box to the casting box, in order that the plate may retain its flat
condition when cold.
In this way a copper shell can be backed up in a few minutes, and the resulting
electrotype plate is practically perfect on the face and equal in that respect to the
type or cut from which the mould for the electro was taken. The plate may be
cast to any desired thickness and will usually only require one cut or shave in
the planing machine to give it a smooth back suitable for "impression
" in
printing.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
The hereinabove described method or process of producing electrotype plates
for printing purposes which consists in placing an electrotype shell, prepared
substantially in the manner described, face downwards in a casting box heated to
a temperature somewhat higher than the melting point of the metal or alloy used
to tin the shell and retaining the edges of the shell in place by grooved guides that
will permit the shell to expand but will prevent backing metal passing to its face,
and pouring the backing metal into the space between the shell, guides and opposite
side of the casting box, a sheet of material that is a bad conductor of heat having
previously been placed between such side and the guides and shell, and a layer of
sheet material having previously been arranged at the top of the box to serve as
a guide to prevent backing metal passing to the face of the shell, removing the
electrotype plate thus produced from the casting box, and cooling it under pressure,
as set forth.
Datel tot 1
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1