IMPROVE. MENTS IN ROTARY COLOR PRINTING MACHINERY
Year: 1876

page_text: LETTERS PATENT to James Dobson, of Edinburgh, North Britain, Printer, and
Arthur McCardle, of the same Place, Printer, for the Invention of " IMPROVE.
MENTS IN ROTARY COLOR PRINTING MACHINERY."
Sealed the 12th January 1877, and dated the 12th July 1876.
PROVISIONAL SPECIFICATION left by the said James Dobson and Arthur
McCardle at the Office of the Commissioners of Patents on the 12th July
1876.
JAMES DOBSON, of Edinburgh, North Britain, Printer, and ARTHUR McCARDLE,
of the same Place, Printer. "IMPROVEMENTS IN ROTARY COLOR PRINTING
MACHINERY."
The object of this Invention is to provide a machine that will throw off im-
pressions in two or more colors from stereotyped plates, lithographic stones, or
equivalent printing surfaces with economy and dispatch. To this end, supposing it
is intended to print from raised surfaces in, say, two colors, we fit the periphery of
a horizontal cylinder with two sets of stereotyped plates, one set to receive, say, red
ink, and the other black ink. These sets of plates we make the complement the
one of the other by removing from the plates that are to receive the black ink those
parts which it is intended to reproduce in red ink, and vice versa. Above the type'
cylinder we mount the inking apparatus for the two colors, and operate the saine
by suitable gearing.
The distributing cylinder of each apparatus is carried by an axle that is mounted
in stationary bearings, but the feed rollers for these cylinders are carried by rocking
arms. Pendent from the axles of the distributing cylinders are pairs of swinging
arns for carrying the inking rollers. These rollers work in pairs, and are always
in contact with their respective distributing cylinders.
The carrying arms of the distributing cylinders for each color are connected
together by toggle levers, and these levers are connected by rods with a rotating
cam, which serves to lower the inking rollers into contact with the printing
surfaces, and at the proper time to lift them clear of the same, and retain them in
a raised position until until the plates which they are intended to ink are presented
to their action. In like manner the ink feed rollers are lifted from their respective
D 071

page_text: distributing cylinders by this cam action, and lowered when the inking is required
to proceed.
Between the type cylinder and the feed board we place the impression cylinder,
which turns in adjustable bearings, and is fitted with grippers for seizing the
paper.
When the machine is constructed for printing two colors the impression cylinder
will be so proportioned with respect to the type cylinder as to make when rotating
at the same surface speed as the type cylinder two rotations for one of the type
cylinder, and so on in proportion according to the number of colors used, in order
to present the paper to the whole surface of the type cylinder. When this is
effected the grippers will release the paper, and it will be delivered on to endless
tapes, which will carry it down opposite a flyer that receives a vibratory motion
from a segment rack and pinion. This flyer passing through the tapes will take up
the printed sheet, and lay it upon the delivery board.
To facilitate the drying of the ink on the printed paper, and prevent an offset, an
endless blanket may be provided below the impression roller, and being heated by
travelling over steam heated rollers will present a drying surface to the printed
paper.
Supposing the cylinder which we have termed the type cylinder to be fitted
with lithographic stones or zinc plates, it will be necessary to provide a means for
keeping the printing surfaces wet. In contact with this cylinder is a damping
cylinder covered with felt or other absorbent substance, and leading up to this
cylinder is an endless blanket, which rotates in a trough of water, and by pussing
between a pair of nipping rolls has any excess of moisture which it may take up
wrung out.
The wet blanket imparts moisture to the damping cylinder, and this in turn
keeps the printing surfaces damp. This cylinder is carried by adjustable bearings,
by which any desired pressure may be given to the damping cylinder.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Dobson and Arthur McCardle in the Great Seal Patent Office
on the 12th January 1877.
JAMES DOBSON, of Edinburgh, North Britain, Printer, and ARTHUR MCARDLE,
of the same place, Printer. "IMPROVEMENTS
IN ROTARY COLOR PRINTING
MACHINERY."
The object of this Invention is to provide a machine that will throw off impres-
sions in two or more colors from stereotyped plates, lithographic stones, or
equivalent printing surfaces with great accuracy of register, economy, and dispatch.
To this end, supposing it is intended to print from raised surfaces in, say, two
colors, we fit the periphery of a horizontal cylinder with two sets of stereotyped
plates, one set to receive, say, red ink, and the other black ink. These sets of plates
we make the complement the one of the other by removing from the plates that aro
to receive the black ink those parts which it is intended to reproduce in red ink,
and vice versa. Above the printing cylinder we mount the inking apparatus for
the two colors, and operate the same alternately by suitable mechanism.
In the accompanying Drawings our color printing machine is shewn in sectional
elevation at Fig. 1, and in partial end elevation at Fig. 2, the same being arranged
to print in two colors from stereotyped plates.
Figures 3, 4, and 5 are detail views on an enlarged scale of the means employed
for attaching the plates to the printing cylinder. The main framing of the machine
is shewn at A, in the centre of which is mounted the cam shaft B. Keyed to this
shaft is a spur wheel B¹, which gears into and is driven by a pinion C on the
driving shaft C. In gear with the wheel B¹ is a spur wheel D¹ of like pitch, which

page_text: is keyed to the axle of the printing cylinder D. This spur wheel D₁ gears into and
drives a spur wheel E', having half its number of teeth, which wheel E' is keyed to the
axle of the impression cylinder E. This cylinder is mounted in adjustable bearings
in the main frame A. The diameter of the cylinder E, is so proportioned to that
of the cylinder D that it will make two rotations in contact with the printing
cylinder while the cylinder is making one rotation under the two sets of inking
rollers. When however three colors are intended to be printed the proportions of
these cylinders and for the driving gear in connection therewith will be as three to
one, three plates or three sets of plates being in that case used to complete the
complement of the printing surfaces. F is the feed board, which is capable of
rising and falling, as will be hereafter explained, to clear the grippers e carried by
the impression cylinder. G is the receiving board; H, the fly for delivering the
printed paper thereto; and I, the endless travelling tapes for receiving the printed
paper as it leaves the impression cylinder E; K and K¹ are the ink or colour troughs
situate at the top of the fame A, and above the printing cylinder. Each of these
troughs is fitted with an ink delivering roller k, k, and below these are mounted
on rocking arms L, L', the transferring rollers 1, 1, which are brought alternately
into contact with their respective rollers k, l, and the distributing cylinders M, M¹,
to take up with and deliver it to the distributing cylinders.
The axles of these cylinders are mounted in fixed bearings in the framing A, and
pendent from each end of these axles is a pair of arms N, which carry at their
extremities a pair of inking rollers n, n¹. Each pair of arms N is connected by
links to a rod N¹, which is jointed to an arm N² that has its fulcrum on the main
framing. A friction bowle carried by the arm N³ bears upon a cam N³ on the cam
shaft, and by the rotation of this cam the inking rollers, which are always in contact
with their distributing cylinder, are raised from or dropped into contact with the
rotating printing surface of the cylinder D, by which means their action upon the
printing surfaces is timed to suit the work in hand.
Supposing the inking rollers n, which receive ink from the color trough K to
impart black ink to the cylinder D, and the inking rollers n³, which are in con-
nection with the color trough K¹, to impart red ink to the cylinder D, then the
cams which respectively maintain these rollers out of action must be so timed as to
provide for the proper alternate action of the two pairs of inking rollers, or for. the
lifting of the one pair of rollers, that the surface already inked or to be inked by
the other pair may pass freely under or out of contact with that pair of rollers.
An intermittent rotary motion is given to the ink delivery rollers k, ¹, by
means of a ratchet wheel and pawle (see Fig. 2), the pawle being carried by an
arm loose on the axle of the roller, and receiving a reciprocating action through
a rod from a cam on the cam shaft B.
The distributing cylinders M, M¹, receive rotary motion from suitable gearing,
not shown in the Drawing, and they have besides a shogging or endway motion,
which is imparted to them by a rack lever actuated by a worm in the usual
manner.
The rising and falling motions of the ink transferring rollers 1, 1', are obtained
from suitable cams on the cam shaft B acting upon bent rods, which are jointed
to an arm keyed to the fulcrum pin of their respective rocking arms L, L.
A convenient mode of fixing the stereotyped plates to the cylinder D is shewn at
Figures 3, 4, and 5. This is to form in the periphery of the cylinder longitudinal
dovetailed slots d, into which are fitted metal bars of corresponding form. Over-
lying these slots at a position determined by the width of the plates D are clamping
pieces d², which are connected to the bars d' by screws d³, and are caused to grip
the plates at their edges. By slackening these screws the clamps may be slidden
out of contact with the plates, and the same may be removed and replaced by
others of a like or of a different size, the clamps being adjustable lengthwise of the
cylinder.
In advance of the feed board F are guiders ƒ for determining the position of the

page_text: sheets of printing paper fed to the machine. These sheets as they are severally
brought over the impression cylinder are seized by the grippers e, which work in
recesses formed for them in the cylinder, the grippers being pressed down upon the
edge of the paper by springs as usual. The grippers e, of which there will be two,
three, or more according to the width of the machine, are made fast to a transverse
axle e¹ and upon one end of this axle is keyed a spur pinion e², through which the
motion for opening the grippers and releasing the printed sheet is transmitted. In
gear with the pinion is a segment rack carried by a rock lever es, which is
pivotted to the side of the cylinder E. The tail of this rock lever is fitted with a
bowle which bears upon a segment guide forming the termination of a cranked arnı
or lever E2 that has its fulcrum at et on the main framing. This arm E² carries a
bowle which overlies a cam on the cam shaft, and by the rotation of this cam the
cranked arm is raised once for every rotation of the cam shaft B, and thereby caused
to tip the rock lever and open the grippers e after the paper has been submitted
to the impress of the whole printing surface of the cylinder D. This motion will
take place at every second rotation of the impression cylinder and immediately after
the open grippers rise to the feed board to receive a fresh sheet of paper.
To facilitate the removal of the printed sheet from the cylinder E and delivering
it on to the endless tape T a blast of air may be used, or a rotary brush in the
manner well understood. In order however that the grippers may clear the feed
board, the front part of that board is hinged to permit of its rising out of the way,
and to effect this there is mounted below the feed board a rock lever f¹, the tail of
which is connected by a link rod f to a rock lever f³, pivotted at to the main
framing. The free end of this rock lever carries a bowle which bears upon a cam f
of the cam shaft, and by the rotation of this cam the rock lever f¹ is caused to lift
the feed board F sufficiently high to be clear of the ascending open grippers. As
the grippers rise above the feed board the attendant moves forward a sheet of paper
towards them, and immediately the tail of the lever a clears the segment guide of
the arm E the grippers will close on the paper, and it will then be drawn into the
machine to receive the impress of the printing surfaces.
Supposing the plates which are to give off a black impress to have been first
inked, the inking rollers in connection with the red color trough will be in a raised
position until such plates have passed those rollers; when however this has taken
place the inking rollers of the black colored trough will be raised, and those of the
red colored trough will be depressed; thus while the printing off of the impression
in black ink is taking place, the inking of the second set of plates with red color
will be proceeding, and these will then in turn impart to the paper the color which
they have received. If now the plates are properly adjusted on the printing
cylinder it will follow that a good register will be obtained as the paper on the
impression cylinder will remain undisturbed until the printing is completed.
To facilitate the drying of the ink on the printed paper and prevent the smearing
of the impression, endless blankets O, O, are provided below the impression cylinder.
These blankets are led under and over steam licated rollers, to which rotary motion
is imparted in any convenient manner, and it will thus present a drying surface to
the printed paper.
For the purpose of cleaning the stereotyped plates a cylinder P is employed to
receive an endless blanket P¹ which is kept in contact with the printing cylinder,
and is held at tension by a cylinder P. Rotary motion is communicated to the
cylinder P (which is carried by adjustable bearings in the main framing) by a spur
wheel P³, which gears into the spur wheel 11 of the cylinder D, and thus the
blanket is caused to pass over the plates after they have passed the impression
cylinder.
Supposing the printing cylinder D to be fitted with lithographic stones or zinc
plates arranged after the manner of the stereotyped plates before mentioned, it will
For this
be necessary to provide a means for keeping the printing surfaces wet.
purpose the cylinder P is coated with felt or other absorbent substance, and leading

page_text: up to this cylinder is an endless blanket, as at P¹, which rotates in a trough of
water P, and by passing it into the nip of the cylinder P2 and the roller p any
excess of moisture which it
may take up is wrung out.
The cylinder P is carried by adjustable bearings, by which any desired pressure
may be given to the damping cylinder.
Having now set forth the nature of our Invention of "Improvements in Rotary
Color Printing Machinery," and explained the manner of carrying the same into
effect, we wish it to be understood that under the above in part recited Letters
Patent we claim,―
First. The arrangement of parts above described whereby the register is auto-
matically obtained, the sheet being retained on the impression cylinder until the
impress of the whole of the printing surfaces carried by the printing cylinder has
been received on to the sheet.
Secondly. The arrangement of inking apparatus above described, whereby two or
more sets of inking rollers are brought into action alternately or in proper sequence,
in the manner and for the purpose above explained.
Thirdly. The means above described for "setting" the ink while the paper is on
the impression roller.
In witness whereof, I, the said James Dobson, have hereunto set my hand and
seal, the Ninth day of January, in the year of our Lord One thousand
eight hundred and seventy-seven.
JAMES DOBSON. (L.s.)