Improvements in the Manufacture of Counter Dies.
Year: 1899

page_text: Date of Application, 10th Mar., 1899
Complete Specification Left, 7th Dec,, 1899-Accepted, 3rd Mar., 1900
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Counter Dies.
I, ROBERT JAMES COPAS, of No. 41, Grays Inn Road, in the County of London,
Artist and Engraver, do hereby declare the nature of this invention to be as
follows:
-
This invention relates to improvements in the manufacture of counter dies
and has for its object to facilitate the distribution of the material of which
the die is composed; to permit of drying the counter die more rapidly without
causing shrinking or warping; to allow of a thinner metal plate or support
being used than heretofore, and to obviate the use of tools (other than those used
in perforating the plate) or etching in the preparation of the said metal
support.
For these purposes 1 use a perforated metal plate which I embed in the
material of which the die is to be composed. The perforations in the plate
are of a smaller diameter at the underside than on the upper surface; a backing
of celluloid or other suitable material in a plastic state is driven by pressure
through the perforations so that when it is necessary for portions of the front
of the die to be routed away, the dovetail shape of the material, with which
the perforations are filled will give the backing support and cause it to firmly
adhere to the metal plate. A grooved plate is placed beneath the backing of
plastic material along the grooves of which the material is driven and allowed
to escape or is driven up again through the perforations into the deeper parts
of the work in the die or matrix at the top thus obtaining, with less pressure,
heat, and use of solvent, a thinner counter die than heretofore. The perforations
in the plate may be made by punches and the burr caused thereby subsequently
rolled down, or taper punches, or templates, may be used, thus producing the
dovetail hole.
I first clean the rolled perforated plate by scratch brushing and washing and
then prepare a sheet or layer of the plastic material upon an oiled grooved metal
plate. The upper surface of the plastic material is then treated with a little
of its solvent. Upon this upper surface I lay the perforated plate and press it
into close contact with the plastic material beneath it. The perforations are
now filled with the solvent to exclude air. Another sheet or layer of the plastic
material is then placed upon upon the perforated plate, the lower surface of
this sheet or layer having been previously treated with its solvent, and it
is then pressed into close contact with the perforated plate and lower layer
of plastic material. I then place, face downward, the oiled electrotype. brass
or other die (or matrix) and place it under pressure cold in a suitable press or
under a weight for an hour or so to give time for the solvent to be thoroughly
absorbed by the plastic material and for the latter to be driven up and down
into the perforations uniting together in same. The two layers of plastic
material containing the metal plate, together with the electrotype, brass, or

page_text: other die (or matrix) are now placed in a press suitable for making dies and
the moulding is finished by pressure with a degree of heat suitable to the
material used. Subsequently it is, if the material used require it, dried in a
suitable chamber by heat. Should the form of the holes in the metal plate
shew through the die, or matrix. the die, or matrix, is, after being partly dried
pressed a second time, and the form of the holes will not be reproduced in the
embossing.
To ensure a good grip on the platen or cylinder the corrugated under surface
of the celluloid (or other material) backing, may he rubbed with glass paper,
or a file passed over it which will remove any roundness on the outer portions
of the corrugations.
JAMES G. STOKES,
4, Dane's Inn, Strand, London, W.C.,
Agent for the Applicant.
Improvements in the manufacture of Counter Dies.
I, ROBERT JAMES COPAS, of No. 41, Grays Inn Road, in the County of London,
Artist and Engraver, 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 improvements in the manufacture of counter dies
and has for its objects to facilitate the distribution of the material of which
the die is composed, to permit of drying the counter die more rapidly without
causing shrinking or warping to allow of a thinner metal plate or support
being used than heretofore, and to obviate the use of tools (other than those used
in perforating the plate) or etching in the preparation of the said metal
support.
For these purposes I use a perforated metal plate, preferably of copper, which
if found to have any "spring" in it, so that it will not readily press out flat,
may be annealed before using. In the case of copper I do this by making it
hot to a bluish-black colour, over a bunsen burner, and suddenly cool it by
pressure in any cold iron press, and such plate I embed in the material of which
the die is to be composed. The perforations in the plate are preferably of a
smaller diameter at the under side than on the upper surface; a backing of
celluloid or other suitable material in a plastic state is driven by pressure through
the perforations so that when it is necessary for portions of the front of the
die to be routed away, the dovetail shape of the material with which the per-
forations are filled will give the backing support and cause it to firmly adhere
to the metal plate. A grooved plate is placed beneath the backing of plastic
material, or the bed plate of the press used may be grooved and along such
grooves the material is driven and allowed to escape, or is driven up again
through the perforations into the deeper parts of the work in the die, or matrix,
at the top, thus obtaining with less pressure, heat, and use of solvent, a thinner
counter die than heretofore. The perforations in the plate may be made by
punches and the burr caused thereby subsequently rolled down, or taper punches.
or templates, may be used, thus producing the dovetail hole.
The accompanying drawing illustrates, to an enlarged scale, a sectional eleva-
tion of a matrix, die and grooved bed plate, according to my invention.
A is the matrix, B the upper surface of the die. C the perforated copper

page_text: plate, embedded in the material of which the die is composed. D the grooved
bottom of die. E the bed plate of press, having a grooved surface to form the
grooves on the bottom of the die.
The thickness of the perforated copper plate, for ordinary work is about one
thirtieth of an inch. If the perforations are circular, about 150 perforations
to the square inch is a suitable number, but for counter dies made from dies in
which the work is unusually deep a proportionately thicker perforated plate is
required, and the perforations larger, and fewer to the square inch. The grooved
plate may be grooved with straight parallel grooves, having little or no space
between them, and about twenty five grooves to the inch is a suitable number,
the depth of each groove to be about the same as its width and they may be made
by a V shaped tool on an ordinary planing machine.
I first clean the roller perforated plate C by scratch brushing washing and
drying and then prepare a sheet or layer D of the plastic material úpon an
oiled grooved metal plate E. The upper surface of the plastic material is then
treated with a little of its solvent. Upon this upper surface I lay the perforated
plate and press it into close contact with the plastic material beneath it.
The perforations are now filled with the solvent to exclude air. Another sheet
or layer B of the plastic material is then placed upon the perforated plate, the
lower surface this sheet or layer having been previously treated with its
solvent, and it is then pressed into close contact with the perforated plate C
and lower layer D of plastic material. I then place upon it, face downward
the oiled electrotype, brass, or other die (or matrix) A and place them under a
pressure cold, in a suitable press, or under a weight, for an hour or so, to give
time for the solvent to be thoroughly absorbed by the plastic material and for
the latter to be driven up and down into the perforations, uniting together in
The two layers of plastic material containing the metal plate, together
with the electrotype, brass or other die (or matrix) are now placed in a press
suitable for making dies, and the moulding is finished by pressure, with a
degree of heat suitable to the material used. Subsequently it is, if the material
used require it, dried in a suitable chamber by heat, and the edges may be
trimmed with shears or a card cutter.
same.
Should the form of the holes in the metal plate shewn through the die (or
matrix) the die (or matrix), is, after being partly dried, pressed a second time,
and the form of the holes will not be reproduced in the embossing.
To ensure a good grip on the printing or embossing press, the corrugated
under surface of the celluloid (or other material) backing may be rubbed with
glass paper, or file passed over it, which will remove any roundness on the
outer portions of the corrugations.
By having spaces between the top and bottom layers of plastic material,
into which the material is driven by pressure, and a grooved plate at the bottom,
along the grooves of which the plastic material is driven and allowed to escape,
or is driven up again into the deeper parts of the work in the die (or matrix)
at top, a thinner counterdie is obtained. with less pressure than heretofore and
the distribution of the material is facilitated. These dies also permit of under-
laying in parts, with plastic material, for the deeper portions of the work, instead
of having thicker material over the whole of the plate, as heretofore.
In drying the counter dies by means of a gentle heat in any ordinary heating
store or cupboard, the material being on both sides of the plate, and united
through the perforations both sides dry equally, without shrinking or warping.
Counterdies constructed as above, permit of a thinner metal plate being used
as a support, and also afford increaded facilities in modelling, and in routing
and bevilling those parts of the die not occupied by the work, and preservatives,
súch as oils, glue or paper are not necessary to prevent the die warping or
shrinking when stored away. They may also, unless the spaces have been
lowered away, when injured by accident or otherwise, be repaired from the back
by the application of further plastic material.

page_text: Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
1 claim is
In the manufacture of counterdies the use of a perforated copper, or other
metal, plate, embedded in the material of which the die is composed, substantially
as and for the purposes specified.
11
1
1
1000
JAMES G. STOKES.
Chartered Patent Agent,
4, Dane's Inn, Strand, London, W.C.,