IMPROVEMENTS IN AND CONNECTED WITH PRINTING MACHINES
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by John Halliday Young and Robert
Paterson at the Office of the Commissioners of Patents on the 23rd August
1881.
JOHN HALLIDAY YOUNG and ROBERT PATERSON, both of Glasgow, in the County
of Lanark, North Britain. "IMPROVEMENTS IN AND CONNECTED WITH PRINTING
MACHINES."
This Invention relates to improvements in and connected with double cylinder
perfecting printing machines, in which the sheets are printed on the one side by
the "forme" of type under the first cylinder, and have the other side printed by
the forme under the second cylinder when the sheet is reversed. The object of the
present improvements is (first) to prevent the "set-off" or impression made on the
second cylinder by the letter press on each wet printed sheet passing under it
being transferred from the cylinder to the next sheet in succession, and (second)
to secure the delivery of the printed sheets from the machine by mechanical
devices instead of by manual labour as heretofore.
To obviate "set-off" in printing with machines of the kind referred to, a
"set-off" sheet is commonly employed, and is passed with the sheet being printed
between the printed surface of the latter and the second cylinder, and the use
of such sheets to receive the "set-off" involves waste of paper and of the time
and labour of attendants employed to enter and remove the set-off sheets. By the
present improvements the use of such sheets is entirely dispensed with, the printed
sheets being allowed to come in contact with the blanket or calico of the second
cylinder, and the impression being removed to prevent "set-off" by means of
cleaning rollers saturated with cleaning mixture specially prepared for the
purpose.
In carrying out this part of the Invention, two or more wooden rollers covered
with printer's blanket are mounted over the second printing cylinder on iron
spindles to revolve in bearings in the main sliding side frames which carry, and
raise, and lower the cylinder. These rollers are made to revolve in the opposite
direction to the rotation of the printing cylinder, and are fitted and adjusted to
bear or rest on the surface of the cylinder, so that the effect of these rollers is to
rub off the set-off ink on the surface of second cylinder. The first roller or its

page_text: blanket is saturated with turpentine, which, when the machine is at work, moistens
and partially cleans the surface of the cylinder revolving under it. The second
roller is saturated with the new cleaning mixture, which entirely removes the ink
and cleans the cylinder, and a third roller may, if desired, be used to dry the
Burface of the cylinder.
The new cleaning mixture is composed of stearine dissolved in benzol or other
volatile oil, to which soft or black soap is added, and the proportions of the
ingredients are by preference as follows, namely:-One half pound of stearine
dissolved in one gallon of benzol or volatile oil, with the addition of one half
pound of soft or black soap. This mixture is boiled until the solids are thoroughly
dissolved; it is then allowed to cool, and placed in a covered vessel to prevent
evaporation. The mixture is applied to the roller or rollers by a sponge, or by
other suitable means; and as the rollers become solid with the ink from the
printing cylinder, they are removed to be cleaned when the machines are not in
operation, as during the workmen's meal hours, or at night.
The second part of the Invention relates to the application of mechanical means
for delivering the sheets from the printing machine after they are printed on both
sides, and it consists in extending the endless tapes or bands which travel round
the second cylinder to run parallel with and out beyond the separate bands which
are usually employed to raise the sheets from under the cylinder to be caught by
the attendants. For this purpose long arms or bars are fitted on a transverse shaft
fitted to the frame of the machine which carries the ordinary spindles and pulleys
over which the tapes travel. Small pulleys are fitted on the ends of these arms,
and the endless tapes are carried out over and round these pulleys, and made to
travel over the delivery board, which is also fitted to lie in an inclined position.
The sheets, as they leave the printing cylinder, are carried up between the cylinder
tapes and the usual separate lifting tapes, and as the cylinder tapes extend further
up and over the delivery board the sheets are carried or thrown over the tape
roller on to the delivery board or table. Guides are provided on this board or
table, and are fitted on each side to secure an even delivery, and to keep the sheets
from spreading. The arms carrying the pulleys, with the extension of the endless
tapes, can be swung up by turning the shaft on which they are fixed, and can
thus be removed out of the way when preparing for printing.