Improvements in Multicolor Printing Presses.
Year: 1894

page_text: Date of Application, 10th Apr., 1591-Accepted, 16th June, 1894
COMPLETE SPECIFICATION.
[Communicated from abroad by ЕмMA LOUISA FORBES, of 233, Chestnut
Avenue, Jamaica Plain, Boston, Massachusetts, U.S.A., Gentlewoman.]
Improvements in Multicolor Printing Presses.
I, CHARLES AUBREY DAY, Chartered Patent Agent, of 321 High Holborn, in
the County of London, 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 is related to an important class of printing machines intended for
the production of pictures and ornamental delineations in two or more colors; and
more specifically to those adapted to print on sheets of paper, and on the same side
of each sheet, a number of superimposed impressions each with an ink of such a
color as in the aggregate will produce the desired design at every complete
revolution of the press.
In the press which forms the subject matter of this invention, the sheet of paper
is fed to an impression-cylinder, on which two or more impression-surfaces of
sufficient size are provided. These surfaces are separated from each other by gaps
across the cylinder of the usual dimensions, and in each gap grippers are placed
which are constructed and operated in the well known way to seize the leading edge
of the sheet as the same is presented to them at the end of a feed-board or other-
wise. Each impression-surface bearing its sheet of paper is then carried past a
number of form-cylinders which revolve operatively against the impression-cylinder.
The form-cylinders are all of equal diameter and are provided with two forms
each, separated by gap-spaces or depressions which correspond in size and angular
position with the gaps on the impression-cylinder, so as to register with the same in
passing. The relation between the impression and form-cylinders is such that half
the diameter of one of the latter is an aliquot part of the whole diameter of the
impression-cylinder. Each form is inked with the color it is to print; and as a
sheet upon one of the impression-surfaces passes a form it receives an impression
from the same, and going on to the next form-cylinder receives a second impression
in another color upon the first, and so on to the end of the color series. In this
press the same form cannot print on two adjacent impression-surfaces, but invariably
skips one such surface. The intervening impression-surfaces thus passed over are,
without loss of time, receiving impressions from the second series of forms, so that
every time a sheet is fed another has received all its colored printings be they few
or many. Such a sheet when completed is discharged from the press before the
impression-surface which carried it reaches the feed-board, where it gets a new
sheet.
In the drawings, which are all diagrammatic,
Fig. 1, is a press printing five colors.
Fig. 2 shows a modified arrangement of the inking apparatus, and
Fig. 3, is a two color press.
The first figure shows a large impression-cylinder marked 10, on which there are
seven impression-surfaces 12, packed as is usual in printing machines with rubber
blanket, paper, cardboard, &c., to receive impressions from the forms. These
surfaces are large enough to carry the largest sheet which it is intended the press
shall print. The paper on the feed-board 14 is fed to the grippers 16 of ordinary
construction operating in the gaps 18, which separate the impression-surfaces. In
Fig. 1, there are five form-cylinders 26 and the press is intended for printing five
colors only. Each form-cylinder carries two forms the circumferential length of

page_text: either one of which together with that of one of the separating gap-spaces 22, being
equal to that of one impression-surface 12 on the impression-cylinder, and the gap 18
belonging thereto. The gap-spaces or depressed surfaces 22 on the form-cylinders
that separate the forms, it will be understood, are not for the same purpose as those
containing grippers, for their function to represent in length on the surface of the
form-cylinders said gaps 18 on the impression-cylinder and provide room for the
devices which strain and hold the curved forms upon the suitable form supports
arranged for them. This is done in many different ways well understood and not
shown in the figures. These forms are marked near the leading edge, in the order
in which they print. Nos. 1¹, 21, 3, 4, and 51; and Nos. 1, 2, 3, 4, and 5; the
first series giving the picture by printing on every second form-surface and
skipping those that are intermediate; while the second series prints upon the
surfaces omitted by the first, a picture identical with the first as far as the colors
which compose it are concerned. The inking apparatus for these ten forms are
marked 24, and in such a press may be stationary, the forms passing under the fixed
form-rollers and receiving their ink just before they reach the paper, and as this
takes place as each one of the two forms passes the form-rollers, the same color is
necessarily printed by.each. But it does not follow that the designs on each series
of forms should be the same, though they must of course be each consistent among
themselves and print in register one after the other on each sheet fed to the
impression-cylinder; nor, for like reasons, does it follow that the two forms must be
identical in size.
This multicolor press might be under-fed (as in Fig. 3), directly from a feed-
board carrying the leading edge of the sheet direct to the grippers which are to
take it, but I prefer to adopt another method which is better adapted to the objects in
view. For this purpose I employ a feed-cylinder 26 geared to the impression-
cylinder, which is provided with two sets of grippers diametrically opposed to each
other. To these the sheets of paper are over-fed from the feed-board 14, and are
by it carried to the grippers belonging to the several impression-surfaces as they
pass. The delivery of the printed sheets is made face up, in a way well understood,
by curved stripping fingers at 28, and over tapes 30, to a table or other receptacle.
The pinion at 32 drives this machine in the usual way.
In Fig. 2, a part of the press just described is drawn for the purpose of showing
a modification which in many cases is of value. This consists in making use of two
sets of inking apparatus to ink the forms. These are provided with cam arrange-
ments for dropping the form-rollers at the proper time, so that it is thereby possible
to employ the press for the production of two jobs of work at the same time differing
from each other both in design and color. It is obvious that a press so furnished
with lifting form-rollers to bring the desired colors upon each of the forms, avoiding
and inking each alternately, may also be used for a single color and for duplicate
designs also if desired.
Fig. 3, shows a two color press which has an impression-cylinder with only two
impression-surfaces upon it and two form-cylinders 20, bearing each two forms and
one set of inking apparatus 24 for each. The feed to this press is under from the
board 14, and the delivery is as before by fingers 28 and tapes 30.
This press offers many advantages. That it is very rapid is obvious, the reason
lying in the fact that all the several colors are being printed together and almost
all the time, however numerous the forms may be.. In addition, the small angle
covered by a form, renders it easy to bend and strain flexible metal sheets bearing
the etched design over the form-supports, and hold them while making ready
and printing.
Having thus described my invention I wish it understood that I do not confine
myself to the specific details of construction bere shown, for it is plain that the
same may be greatly modified without affecting the principles on which my
invention rests. It may for instance, be explained that although two forms upon
each form-cylinder will usually prove most valuable in practice, and the description
hereinbefore given has been confined to that aspect of my invention, for the reason

page_text: stated, and to avoid complexity, still a larger number of forms can be used, and in
certain cases (as with small work and short editions thereof), with advantage. The
law above stated, defining the relations between the diameters of impression- and
form-cylinders may then be generalized by stating, that when two forms are used
half the diameter of the latter must go into the diameter of the former without a
remainder; when three are used, one third must do the same; and when four,
one fourth must be the aliquot number, and so on indefinitely. And, it is further
manifest, that as when two forms are employed one impression-surface is always
skipped, so when three are held upon the same form-cylinder two such surfaces
will be skipped, and should four be used three impression-surfaces will pass a form
before it prints again, and so with higher numbers.
In this press the dimensions of the impression-surfaces must be large enough
for the largest sheets to be printed; but it is plain that smaller sheets and smaller
forms to correspond may without any difficulty be substituted for those of full size at
any time. The statement should also be made, though it is of itself sufficiently
obvious, that although every second impression-surface may be skipped in printing, it
by no means follows that the total number of such surfaces should be even. In Fig. 1,
the number is odd, so that any one form in that press, while adhering to its own
series of impression-surfaces so far as the production of work is concerned, will
have been in contact with them all when the impression-cylinder has made two
complete revolutions.
Having now particularly described and ascertained the nature of the invention,
and in what manner the same is to be performed, I declare that what I claim is:
1. A multicolor printing machine consisting of an impression cylinder having
two or more impression-surfaces of equal size, with a gap for each containing
grippers; in combination and in operative contact with two or more equal-sized
form-cylinders the radius of each of which is an aliquot part of the diameter of
the impression-cylinder; with two forms on each of said form-cylinders, each form
covering less than half its circumference and adjusted, angularly, to register with
an independent series of the impression-surfaces; and with inking apparatus for
each form cylinder adapted to ink both forms with a single color; substantially as
described.
2. A multicolor printing machine consisting of an impression-cylinder having
two or more impression-surfaces of equal size, with a gap for cach containing
grippers; in combination and in operative contact with two or more equal-sized
form-cylinders the radius of each of which is an aliquot part of the diameter of
the impression-cylinder; with two forms on each of said form-cylinders, each form
covering less than half its circumference and adjusted, angularly, to register, each
form with an impression-surface after passing the preceding impression-surface and
with two sets of inking apparatus for every form-cylinder, constructed and adapted
to ink each of the two forms thereon independently of each other; substantially as
described.
3. In a multicolor printing press adapted for printing sheets, an impression-
cylinder, in combination and in operative contact with two or more form-cylinders,
each provided with two forms which cover respectively less than half its circum-
ference: with a plurality of impression-surfaces on the impression-cylinder, every
alternate one of which registers with one of the forms of a form-cylinder, and
every intermediate impression-surface with the other; and with grippers for each
impression-surface in gaps on the impression-cylinder between said surfaces;
substantially as described.
4. In a multicolor printing press adapted for printing sheets; the combination
of an impression-cylinder provided with two or more impression surfaces separated
by gaps with two or more forms on two or more equal-sized form-cylinders, a
fraction of the diameter of one of which having unity for its numerator and the
number of forms for its denominator, is an aliquot part of the diameter of the
impression-cylinder; and with formn supports separated by gap-spaces to carry said

page_text: forms, of size and angular position corresponding with the impression-surfaces and
gaps of the impression cylinder, and registering each set of related forms with an
independent series of impression-surfaces on the impression-cylinder; substantially
.as described.
Dated this 10th day of April 1894.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C., Agents for the Applicant.