IN MACHINERY FOR PRINTING METAL PLATES AND IN FIXING DURABLE
Year: 1875

page_text: LETTERS PATENT to Robert Barclay, of 9, College Hill, Cannon
" IMPROVEMENTS
Street, in the City of London, for the Invention of
IN MACHINERY FOR PRINTING METAL PLATES AND IN FIXING DURABLE
Scaled the 14th September 1875, and dated the 20th July 1875.
PROVISIONAL SPECIFICATION left by the said Robert Barclay at
the Office of the Commissioners of Patents, with his Petition, on
the 20th July 1875.
I, ROBERT BARCLAY, of 9, College Hill, Cannon Street, in the City
5 of London, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN MACHINERY FOR PRINTING METAL PLATES AND IN FIXING
DURABLE COLOURED IMPRESSIONS UPON METAL PLATES," to be as follows .-
This Invention has for its object improvements in machinery for
printing metal plates and in fixing durable coloured impressions upon
O metal plates.

page_text: In order to work more advantageously the process described in the
Provisional Specification filed by me and another on the 31st day of
March last, No 1168, I employ printing machinery constructed in the
following manner.-The frame of the machine carries a table to which
a to-and-fro motion is given On the table is fixed a lithographic stone,
which by the motion of the table is carried beneath inking rollers and
also beneath an impression or printing cylinder. To the periphery of
this roller a sheet of cardboard is attached which receives the impression
from the lithographic stone. Over the impression or printing cylinder
is a second or pressure roller or cylinder, and the tin plates or other
metal plates to be printed are passed between the two rollers. The
rotation of the impression or printing cylinder is not continuous, but it
pauses for an instant after the cardboard has passed over the stone, and
during this pause the edge of the metal plate is introduced between the
impression or printing cylinder and the pressure roller. The plate is
accurately placed against a spring stop on the periphery of the impression
or printing roller. When after the pause the rollers again revolve the
metal plate passes between the rollers and the color on the cardboard
is set off on to the plate. The plate is delivered on to small friction
wheels which support it without allowing the impression to be blurred.
Several colors may be printed in accurate register either by different
machines or by the same machine, the lithographic stone, the inking
arrangements, and the cardboard sheet being changed
The same
method can be applied to an impression taken from type or wood and
metal blocks instead of a lithographic stone, and to impressions in more
than one color produced on the sheet of cardboard thus fixed on the
printing cylinder.
In order to fix a color or white ground on the metal plates, whether
printed by this machinery or otherwise, in place of hand varnishing as
is now usual I dust the plates whilst the ink is moist with finely
powdered shellac or other similar gum and afterwards stove the plates.
The powdered shellac may also be caused to adhero either to the printed
impressions or over any larger surface of the plate by means of a second
printing in register in adhesive or tacky printing varnish. Either
ordinary white or coloured shellac may be used.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Barclay in the Great Seal Patent Office
on the 19th January 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
BARCLAY, of 9, College Hill, Cannon Street, in the City of London,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of July, in the year
of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Robert Barclay, Her special license,
that I, the said Robert Barclay, my executors, administrators, and
assigns, or such others as I, the said Robert Barclay, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time, and at all times thercafter during the term
therein expressed, should and lawfully might make, usc, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN MACHINERY FOR PRINTING METAL PLATES AND IN FIXING DURABLE COLORED
IMPRESSIONS UPON METAL PLATES," upon the condition (amongst others)
that I, the said Robert Barclay, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Robert Barclay, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :—

page_text: In order to work more advantageously the process described in the
Specification of the Patent granted to me and another, and dated the
31st day of March last, No. 1168, we employ printing machinery con-
structed in the following manner _The frame of the machine carries a
table to which a to-and-fro motion is given On the table is fixed a
lithographic stone which by the motion of the table is carried beneath
inking rollers and also beneath an impression or printing cylinder. To
the periphery of this cylinder a sheet of thin cardboard or drawing paper
well sized and highly glazed is attached, which receives the impression
from the lithographic stone. Over the impression or printing cylinder
is-a-second-or-pressure-cylinder, and the_tin plates or other metal plates
to be printed are passed between the two cylinders The rotation of the
'impression or printing cylinder is not continuous but it pauses for an
instant after the cardboard has passed over the stone, and during this
pause the edge of the metal plate is introduced between the impression
or printing cylinder and the pressure cylinder. The plate is accurately
placed against a spring stop on the periphery of the impression or
printing cylinder When after the pause the cylinders again revolve the
metal plate passes between the cylinders, and the color on the cardboard
is set off on to the plate The plate is delivered on to small friction
wheels which support it without allowing the impression to be blurred.
Several colors may be printed in accurate register either by different
machines or by the same machine, the lithographic stone, the inking
arrangements, and the cardboard sheet being changed. The same
method can be applied to an impression taken from type on wood and
metal blocks instead of a lithographic stone, and to impressions in more
than one color produced on the cylinder clothed with the highly glazed
drawing paper or cardboard, as before described.
Figure 1 is a side view of a machine constructed according to my
a is the frame carrying
Invention, the principal parts only are shown
a reciprocating table b on which is carried a lithographic stone, or it
may be a surface printing block, or other printing surface, is the
portion of the table b on which the ink is distributed, the ink rollers
being carried in the racks a¹ on the frame a, c is the impression cylinder
clothed with cardboard or other suitable material c' over about half its
circumference It rotates in one ducction with a surface speed cqual

page_text: to that of the printing block, but makes a pause on the completion of
cach rotation just before it reaches the position shown in the Drawing.
d is the pressure cylinder revolving in unison with the impression
cylinder, e is a spring stop When the pauso takes place the plate of
metal to be printed is fed up to the spring stops, and when the cylinders
commence again to move it is pressed forward and made to follow the
stops until the cylinders take hold of it and draw it through, delivering
it on to the small rollers f,f. Thus during tho first half of cach rotation
of the impression cylinder the cardboard surface is printed, and during
the second half rotation the color so printed is transferred to or set off
on a metal plate. The metal plates after printing are stoved and
varnished, and stoved or varnished, and stoved and polished in the usual
manner Shellac, or copal, or other suitable varnishes are employed.
Figure 2 is a side elevation of a machine for transferring or setting off
several colors to the metal plato at one operation. a is the impression
cylinder clothed all round with highly glazed cardboard; around it arc
printing cylinders b, b, b, provided with printing surfaces, clectrotype
blocks may be employed, c, c, c, are the series of inking rollers, each
series working a different color; dis the pressure cylinder. The cylinders
all revolve at the same surface speed As all the colors are printed at a
time the plates may be fed with sufficient accuracy without any pause
taking place at the end of the rovolution, except in cases where the
nature of the design requires registration to another color either printed
previously on the metal plate or to be printed hereafter; also when the
nature of the design requires it to be printed in a definite and exact
position on the metal plate I then use the metal stop, as before
described, and the plate is pushed forward as before described to the
metal stop, and a pause takes place in the rotation of the cylinders as
before described.
The frame of the machine I so construct that the printing cylinders
b, b, b, which are provided with printing surfaces or electrotype blocks
can be readily removed from the machine and others already fitted with
fresh electrotypes substituted, much time is thus economized in printing
short numbers of tin or metal plates.
When it is found that the quantity or intensity of the color which is
thus transferred or set off from the impression cylinder to the plate is

page_text: insufficient it may be increased and rendered more vivid by dusting the
plate in the usual way with color, having previously mixed with the
printing ink an additional quantity of gold size or copal varnish over
and above the usual quantity to render the printing sticky or tacky.
Or the same object may be attained by printing a ground or duplicate
color before printing the final color or colors of the design. In dusting
the plates we prefer to use a dusting machine or machines so as to keep
space with the great speed of the machines. This method of producing
fixed impressions upon iron or copper plates may be varied by printing
in a varnish contaming copal varnish or gold size and dusting with
vitreo enamel colors, in accordance with the well known art of printing
plates of or iron copper in vitreo enamel. The plates are then exposed
to a sufficient heat in a suitable furnace to fuse and fix the said colors
in accordance with the said art.
In order to fix a color on a white ground on metal plates, whether
printed by this machinery or process or by any other, I employ the
following process of fixing it firmly to the metal plate without the uso
of any varnishing process -I dust the colored impression with white
or orange shellac or gum having similar properties, and afterwards
stove the plates so that this powdered shellac is melted on the surface. 2
Or after producing the printed impression on the plate I print in register
upon it a suitable tacky or sticky printer's varnish in the ordinary way
and then apply the powdered shellac, and the plate is then stoved till
the shellac melts on the surface of the color when printed. In this
manner impressions of an exceedingly durable character can be 2
economically produced upon tin plates or other sheets of metal, and
without the necessity of protecting the design by varnishing the wholo
plate. The shellac may in some cases be ground up with the ink or
varnish used.

page_text: I also claim the means of fixing a color ground upon a metal plate,
substantially as described.
In witness whereof, I, the said Robert Barclay, have hereunto
set my hand and seal, this Thirteenth day of January, in the
year of our Lord One thousand cight hundred and seventy-six.
ROBERT BARCLAY. (L.S.)