IMPROVEMENTS IN MACHINES FOR DIE AND PLATE PRINTING
Year: 1878

page_text: LETTERS PATENT to Edward Hewitt, of New York City, in the State of New
York, in the United States of America, for the Invention of "IMPROVEMENTS
IN MACHINES FOR DIE AND PLATE PRINTING."
Sealed the 29th March 1878, and dated the 6th February 1878.
•
COMPLETE SPECIFICATION filed by the said Edward Hewitt at the Office
of the Commissioners of Patents on the 6th February 1878.
EDWARD HEWITT, of New York City, in the State of New York, in the United
States of America. "IMPROVEMENTS IN MACHINES FOR DIE AND PLATE PRINTING."
My machine is of the class in which the die or plate is liberally inked and wiped
automatically, and is by the further operation of the machine powerfully pressed
upon the paper or other material which is to be printed. The wiping is effected by
a long strip of paper or analogous material, which is moved to present clean surfaces.
I have devised improvements in the means of operating the die or plate for the
impression, in the means for inking, in the means for wiping and for moving the
paper as a part of the operation, and for adjusting the pressure by delicately and
uniformly elevating or depressing the counter die while holding its surface exactly
true or parallel.
The following is a description of what I consider the best means of carrying out
the Invention. The accompanying Drawings form a part of this Specification.
Figure 1 is a general side elevation, and Fig. 2 a corresponding plan view.
Fig. 3 is a partial front elevation, showing the means for moving the die or plate
for the wiping.
Fig. 4, section on S, S, in Fig. 1.
Similar letters of reference indicate like parts in all the Figures.
The machine is represented as applied for printing with a small thick plate, or
what may be properly termed a die, and I will so designate it; but it will be
understood that the machine may be made large and adapted to carry thin plates
properly attached, so as to effect what is known as plate printing.
A is a fixed framework, supported by legs or efficient means not represented.
The main driving, shaft B, operated by a belt not represented, gives motion to a

page_text: small gear wheel B¹, to a large gear wheel D¹ fixed on a stout shaft D, which
carries a cam D2, performing important duties.
E is a stout lever turning on a centre e, and vibrated by the cam D² to give a
strong up-and-down motion to a slide G travelling in vertical ways in the horn or
upper portion of the framing. This slide G is dovetailed transversely in its enlarged
lower end, and adapted to hold and carry the die H, and to allow its withdrawal
by a lateral motion when the slide G is in its highest position.
P is a counter die, dovetailed in a stout adjustable bed Q, so that it may be
readily withdrawn by a lateral movement whenever it is desired to omit an
impression without stopping the machine. R is a lever turning on a centre r, and
connected to the sliding counter die P by a link S'. This lever is conveniently
situated to be readily operated by hand.
T is a wedge, bearing firmly on the framing A and supporting the die holder Q
by acting against a correspondingly inclined surface, so that a slight movement of
the wedge T will raise or lower the holder Q, and consequently the counter die P,
while holding it rigidly level; U is a screw taking hold of the upturned end of the
wedge T by means of collars, as represented, and serving to adjust the wedge T,
and consequently the height of the counter die P with great delicacy. Bolts q,
engaging through lugs on the die holder Q, serve to hold the latter against hori-
zontal displacement while the wedge-is-being moved. They may also be tightened
when the parts are rightly adjusted to hold the whole very firmly. The wedge is
formed with a long slot, and the bolts q stand therein.
I will designate the main upper portion or head of the framing by A', and a
höllow extension on one side thereof as A². This part A2 guides the die H, as it
is traversed laterally out and back to be wiped.
The die H is formed with an arm h, having a considerable notch in its upper face,
which engages with an arm I' from the slide I, which latter has a broad bearing
on the face of the framing A2, and traverses in a slot there formed, as plainly shewn
in Fig. 3; J is a bell-crank lever turning on a fixed centre j, and operating the
slide I by engaging its slotted upper arm with a pin from the front of the slide.
The lever J is reciprocated at the proper time by a series of connections from the
shaft D as follows: The cam D³, which is held strongly in the desired position on
the shaft D, depresses a slide K, which rocks the horizontal shaft L by acting on a
roller on the arm L' in opposition to the force of a stout spring M. Another arm L²,
fixed on the shaft L engages by a pin on its end in a slot in the lower arm of the
lever J. It follows that the motion of the slide I, and consequently of the die H,
away from the carrier G, is effected by a positive motion received from the cam D³,
while the return motion is effected by the force of the spring M. The engagement
of the die H with the slide I being effected by an open notch in the top of the
arm h, allows the die to be disengaged by depression and to be again engaged on
its elevation. The depression of the slide G by the powerful motion of the lever E
disengages the die H, and carries it down firmly attached, and forming in effect a
part of the slide. The impression is made under these conditions with the die H,
which has been previously properly inked and wiped. After completing the
impression the return or upward movement of the slide G causes the arm h of the
die H, to again engage by means of its notch with the arm I¹ of the slide I. So
soon as the upward motion of the die stops its lateral motion due to the movement
of the lever J commences. This lever, receiving motion through the train of con-
nections from the shaft D, acts on the horizontal slide I, and moves it briskly away
from the vertical slide G. The die H being engaged by its notched arm h is com-
pelled to accompany the slide I, and it moves out, and with the return of the
slide I moves again back, the dovetail seat for it in the bottom of the slide G,
allowing of its ready withdrawal and return.
The lower or working face of the die H is wiped upon the paper C during nearly
the whole of this movement. The paper C runs over a pair of rollers F at the
proper elevation, and, as the work proceeds, is moved along by being taken up
intermittently on the drum C¹ and given off, as required, from the drum C

page_text: Suitable guide rollers are provided, as shewn, to conduct it properly through the
intervening spaces, and allow the operating mechanism to be at sufficiently distant
points to be out of the way.
The intermittent motion of the paper is so timed that the paper rests motionless
while the impression is being produced, but commences to move out before the
die comes in contact with it to be wiped. Sufficient friction is imposed on the
delivering drum C³, to insure that the paper C shall be always drawn tight.
The wiping paper C is supported between the rollers F by a table F¹, which may
be of thin steel or other suitable material, so as to be slightly elastic. It is
important that the paper be held up by a slightly yielding surface; but I attain
the yielding character mainly from a layer of felt or other elastic material, as shewn
by in Fig. 4, which is glued or otherwise firmly held on the table F¹. The
paper C is drawn tight across this felt, and, as the die rubs strongly over it,
effectually wipes the smoothly polished surface, leaving as in other die and plate
printing only the ink which fills the graven lines.
I have in my experiments attached the felt f to the thin metal table F¹, by
sewing or stitching through a series of small holes made in the latter..
In order to better guide the wiping paper C, and to also hold down its edges so
that they shall never be struck by the die H, I provide guides or fingers, which
cover and hold down each edge of the wiping paper.
I can vary the extent of the travel of the paper C at will. The motion is derived
from a slotted crank or disc D, carried on the shaft D. The pin d is adjustable in
the radial slot therein, and communicates through the link Z' a vibrating motion to
the lever Z, which is pivoted loosely on the shaft of the roller C, and communicates
motion to the roller through a pawl N and a ratchet wheel O. The pawl N may
be held down by a spring, not represented.
The extent of the motion of the paper C may be varied by shifting the pin & out
and in. The time of the motion may be varied by shifting the position of the crank
or disc D on the shaft D. The character of the motion is excellently adapted to
effect the wiping thoroughly, because, being derived from a crank, it is moderate at
the beginning and end, and is most active at the middle of the motion. The middle
and most active period of the motion of the paper is while the die H is stopping and
reversing its motion. During this period the paper moves actively and cross-
wipes.
The inking of the die H is effected immediately before its wiping by rolling with
a roller V, carried in a horizontally moving slide V, which is pushed outward at
the proper time and by the same cam 'D' which induces the pressure. The die H
does not immediately on its rising start off on its lateral movement to be wiped. It
pauses a moment before doing so. During this interval the slide V moves outward,
carrying the roller V₁ across the under face of the die H, and is immediately returned,
by the tension of the spring W.
The ink is supplied to the roller V₁ by a ductor roller X, which supplies the ink
from a fountain Y, being turned by a constant and tolerably rapid motion derived
from the shaft B by a cross belt. It is important that the roller shall turn rapidly
so as to keep its surfaces very freshly coated, and to supply the ink in liberal
quantities and in a fresh condition to the inking roller V1.
Modifications may be made in the details by any good mechanic.
I attach importance to the fact that the same cam D' which operates the main lever
E, also operates the inking, because I am thereby certain that in case of any mis-
placement of the cam the inking will be correspondingly changed in time, and will
avoid breakage. But instead of returning the inking roller by a spring, as shewn,
I can return it by a cam or other positive motion. I have in my experiments
operated successfully returning the inking roller by the aid of two eccentrics, one on
each side of the cani D².
Instead of applying the ink by a roller, I can apply it by a brush or any other
means which will afford a sure, uniform, and sufficiently liberal supply. It is
especially important with some of the varnishes used in die work in colors that the

page_text: inking apparatus shall be of such a character as will not only receive and give up
the ink rightly, but may be readily cleaned with turpentine or other suitable
solvent.
I have experimented with a brush carried on a swinging arm-on the end of the
slide V, and equipped with provisions for giving it a swinging motion as well as the
reciprocating motion due to the slide V. Such brush swings over, and applies its
bristles downward upon the ductor roller X for a sufficient time to become filled
with the ink. It then sweeps over and presents itself with the bristles upward,
and is by the motion of the slide V moved outward and back, so as to apply the
ink upon the face of the die, after which it again sweeps over so as to present its
bristles again downward upon the roller, and receive a fresh supply of ink. This is
very successful, and is superior to the roller in one respect, it carries more ink and
is more certain to completely fill the deep grooves or very heavy lines in the die.
I have even operated with some success without the ductor roller X, dipping the
brush directly into the ink fountain, and only partially removing it by a spring 1
scraper against which it is drawn.
In effecting the wiping motion, instead of returning the die H to its seat in the
dovetail groove of the slide G by the force of a spring M, I can effect the return
motion by positive mechanism. I have in my experiments used wheels with what
is sometimes known as skip gear to set the motion free after moving the slide I, and
consequently the die Houtward, and provide other means for communicating a positive
return motion to the lever J, and consequently to the die H during the period while
the skip gear is inoperative. This affords the advantage that I may control and
modify the time of the return motion of the die as required.
An adjustable stop may be provided to determine very accurately the position of
the counter die P when it is allowed to remain to receive the impression.
A corresponding adjustable stop may be provided to determine the position at
which the moving die H is left in the slide G on the termination of its return
movement.
If it shall be desired in any case to work with the die or plate hot, the parts may
be heated by producing a set of gas burners to play upon the die carrier during the
period while it is being inked. I propose in such cases to so modify the operating
mechanism as will cause it to stand longer in that position and acquire the proper
heat.
I claim as my Invention,―
1st. In a die and plate printing machine, the slide G, reciprocated as shown,
dovetailed across at its lower face, in combination with the die H and with
mechanism for withdrawing the die and returning it after being wiped, as herein
specified.
2d. In a die and plate printing machine, the inking slide V carrying the roller V¹,
or equivalent means for supplying the die previous to its being wiped, in combina-
tion with the main slide G and with the cam D2 carried on the revolving shaft D, as
herein specified.
3d. In a die and plate printing machine, the notched arm h on the die H, in com-
bination with the reciprocating slide I, having an engaging arm I', and adapted to
serve relatively to the slide G and to suitable wiping means, as herein specified.
4th. In a die and plate printing machine, the strip of wiping paper C moved
intermittently across a slightly yielding support F', in combination with a die H,
and with the means G and I for moving the die laterally and vertically at the proper
times, as herein specified.
5th. In a die and plate printing machine, the counter-die P, capable of easy
lateral motion, in combination with the slide G, having a motion to only a definite
extent, so as by the removal of the counter-die to render the motion of the slide
inoperative at will, as herein specified.
6th. In a die and plate printing machine, an ink tank with a roller and ductor,
in combination with an inking roller or equivalent inking device, moved alternately
:
2
4

page_text: in contact with said roller, and with the die or plate, and with wiping or stamping.
mechanism, all operating together, substantially as herein set forth.
In witness whereof, I, the said Edward Hewitt, have hereunto set my hand
and seal, this Twenty-fourth day of December, One thousand eight hundred
and seventy-seven
Witnesses,
CHAS. C. STETSON,
JOHN K. OULAHAN,
Clerks to Thos. D. Stetson,
New York.
EDWARD HEWITT. (L.S.)