AN IMPROVEMENT IN THE MODE OF OBTAINING IMPRESSIONS FROM PRINTING PLATES
Year: 1860

page_text: PROVISIONAL SPECIFICATION left by Alfred Vincent Newton at the
Office of the Commissioners of Patents, with his Petition, on the 28th
September 1860.-A communication from abroad by William Harrison
Oakes, of the City of New York.
I, ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery
Lane, in the County of Middlesex, Mechanical Draughtsman, do hereby
declare the nature of the said Invention for "AN IMPROVEMENT IN THE MODE
OF OBTAINING IMPRESSIONS FROM PRINTING PLATES," to be as follows:-
This Invention relates to an improvement in printing from engraved plates
or those which have the design, figure, pattern, or lettering to be printed sunk
in their surface, and which has hitherto required the paper or other substance
intended to receive the impression to be pressed into the recesses or sunken
portions of the plate, the recesses or sunken portions being filled with ink, and
the raised portions wiped perfectly clean.
This kind of printing, commonly termed copper-plate printing, is, compared
with the operation of a typographical press, very slow and tedious work. In
the former process, the plate requires to be covered or smeared over entirely
with ink, in order to fill the sunken portions, and the surplus ink must then
be wiped off and the surface of the plate left perfectly clean, in order that the
sheet to receive the impression be not soiled. In the latter process, the
design being a raised surface, no wiping and but little manipulation is
required.
The object of this Invention is to expedite the process of "plate printing."
To this end, an ink of a fluid nature is injected into the recesses or sunken
portions of the plate through perforations made in the plate, the ink being
injected into the plate with sufficient force, and while the paper or other sub-

page_text: stance to receive the impression is being pressed upon its face, to leave an
impression on the paper corresponding to the configurations formed by the
sunken portions of the plate. As soon as an impression has been given the
ink is withdrawn from the recesses of the plate, in order to admit of the adjust-
ment of a succeeding sheet and a repetition of the operation.
In the framing of the press and directly underneath the platen there is a
fixed block, the upper surface of which is provided with diverging grooves
communicating with a tube, which passes out through the side of the block
and is in connection with a pipe that branches off to elevated ink reservoirs
and to a pump; placed on the grooved block is a bed, on which the plate to
be printed from rests. This bed has its upper surface grooved longitudinally
and transversely, the grooves intersecting each other and forming sunken pas-
sages over nearly its entire surface. The under surface of the bed is grooved
in zig-zag form, and the bed is perforated with holes which communicate
with the zig-zag grooves, and these grooves communicate with the grooves at
the upper surface of the block.
The plate to be printed from, say, a music plate, must have one hole at
least in each isolated sunken portion of the plate. When placed on the bed
there is a direct communication between the sunken portions in the plate and
the ink-supply tubes. The reservoirs being filled with quite fluid ink and the
plate covered with a sheet of paper or other substance to receive the impres-
sion, the platen is brought down, a valve in a pipe leading from the ink
reservoir is opened, when the ink will flow down and pass into the sunken
portions of the plate and be forced against the sheet covering the plate with a
pressure due to the height of the reservoir above the plate. The valve in the
pipe now closes, and the piston of the pump rises and draws the ink from the
recesses in the plate. The platen then rises and the printed sheet is removed
and replaced by another sheet, when the operation is repeated. As the platen
again descends, the plunger of the pump also descends and forces back the ink
which it drew from the plate into the raised reservoir. At the commencement
of the downward movement of the platen a valve is opened, which forms a
communication between the grooved block and the second reservoir. The
employment of the second reservoir is essential, as it ensures a quick operation
of the press, saving the time which would be otherwise consumed in the
passage of the ink from the first reservoir after the descent of the platen.