IMPROVEMENTS IN PRINTING MACHINERY
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I, BENJAMIN WALTER DAVIS, of 50 Lower Kennington Lane, in the County
of Surrey, Engineer, do hereby declare the nature of the said invention for
"IMPROVEMENTS IN PRINTING MACHINERY " to be as follows:-
"
My invention relates to that class of machines which print both sides of the
paper in its passage through the machine, and are technically known as "perfecting
machines, and is designed to produce a higher class of printing at an increased
speed, to produce a sharper and firmer impression, to prevent "slurring," and to
give a more perfect registor, and an accurate lay.
To effect these improvements use two cylinders as is usual, one to print or
impress the inner side of the sheet upon the inner "forme," carried on the usual
reciprocating table, and the other to print or impress the "outer" side of the shect
upon the outer "forme," also carried on the same table, the sheet being passed from
one cylinder to the other by grippers and tapes.
The two cylinders are geared together, by preference on the outer sido of their
bearings, so that they constantly revolve in opposite directions to one another, and
the driving can be effected from either cylinder.
This I effect in a novel manner direct from the reciprocating "forme" table, by
means of racks, one on either side of the table. This arrangement is in lieu of the
usual train of five or six geared wheels, now used in "perfecting" machines, and
thus I greatly diminish the tendency to "back-lash," and ensure a more perfect
accuracy of relative movement between the cylinders and the "forme" table."
To enable the reciprocating "forine" table to drive the cylinders always in the
same direction, I fit the geared wheels of the cylinders which receive the driving
movement of the table racks with stop motion, so that they are alternately bolted
to the cylinder and set free, the table thus only driving one locked wheel and
cylinder when travelling in one direction, the other wheel running free; and the
other locked wheel and cylinder on its return, the first wheel running free.
This arrangement for driving the cylinder enables me to apply a crank driving
notion to the table, which with the following adjuncts gives an easy and gradual
top and start to the reciprocation and admits of a high speed without shock.
In order to obtain the aforesaid easy reversal, at high speeds without shock and
o prevent the cylinders from overrunning, I preferably check the rotation of the
geared wheels keyed to the axes of the cylinders, as that simultaneously checks the
novement of the reciprocating table.

page_text: I effect this in two alternative methods. To one of the cylinder cog wheels
I fit a crank throw, and carry therefrom a rod, resting upon the face of a cam keyed
to one of the driving shafts. I so shape the surface of the cam that the rod from
the crank, on the cylinder wheel, is always home on the cam, and thus the
movement of the table or other parts is gradually checked without shock.
Alternatively, I add a partially geared wheel to one of the cylinder shafts, and
cause this to gear, as it revolves, into a geared segment, rocking upon a centre
pivot fixed in the frame; or alternatively, I may fix a pin in the circumference of
a disc or wheel on the said cylinder shaft, and cause it to engage in the fork of a
lever rocking on the said pivot. I control the rock of this segment or forked lever
by attaching a connecting rod to it, and allowing it always to bear upon the face
of a cam keyed to one of the driving shafts as aforesaid. The rock of the segment,
when the cylinder comes into gear with it, is thus checked, and the movement of
the cylinder and table reversed without shock.
The method of driving before described also enables ine to bring a third and
central roller bearing under the middle of the "forme" table, and thus to give it
greater rigidity and uniformity of imprint.
To lift the printing cylinders alternately from the "forme" when not printing,
I use a motion, by which I greatly reduce the effect of any wear of the lifting cam
surfaces, upon the rise of the cylinders. Instead of effecting the lift direct by the
constant revolution of a cam of small surface, which will soon show the effect of
wear, I aflix cams of large surface upon the inain driving shaft using their recipro-
cation to oscillate a rocking shaft through a small angle, and utilize this small
angular movement to effect the lift of the cylinders by the throw of an eccentric.
Any wear upon the main cam surfaces is reduced to an imperceptible amount as
affecting the lift of the cylinders.
AT 199.1
FELL & WILDING,
Agents for the Applicant.

page_text: motion.
"1
Figure 4 (sheet 2) is a plan of the cylinders of my improved machine.
Figure 5 is one alternative check motion applied to said machine.
Figure 6 is a second alternative check motion.
Figure 7 is a third alternative check motion.
Figure 8 is a detail of the cylinder lifting gear.
To effect my improvements I use two cylinders A B, as is usual; one to print or
impress the inner side of the sheet fed from the feed board C upon the inner
'forme," carried by the usual reciprocating table D. The other cylinder B effects
the printing on the outer side of the sheet upon the outer "forme," also carried on
the same reciprocating table D, the sheet being passed from one cylinder to the
other by the known system of grippers and tapes a, and delivered eventually on to
the receiving board C¹. The two cylinders A B are geared together by the
wheels E E (Figures 2 and 4) placed by preference on the outer side of their
bearings, so that the cylinders constantly revolve in opposite directions to one
another, and the driving can be effected from either cylinder.
This 1 effect in a novel manner direct from the reciprocating "forme" table D,
by means of the racks d, Figures 2 and 4, one on either side of the table. This
arrangement is in lieu of the usual train of 5 or 6 geared wheels now used in
"perfecting machines," and thus I greatly diminish the tendency to " backlash,"
and ensure a more perfect accuracy of relative movements between the cylinders
and the "forme " table.
"
To enable the reciprocating "forme" table D to drive the cylinders A B always
in the same direction, I fit the geared wheels F F, Figures 2 and 4, which receive
the driving movement of the table racks with a stop motion, shown in detail in
Figure 3. A spring pressed bolt f is fitted inside the end of each cylinder, and
projects through the said cylinder ends engaging with the face of a long inclined
tooth G on the inner face of the wheel F. When then the rack d drives the
wheel F in one direction, the inclined tooth G transmits this motion by the
projecting stud to the printing cylinder; but on the reversal of the rack d and.

page_text: consequent reversal of the wheel F the wedge tooth G upon the latter, slides under
the end of the stud f, compressing it into the end of the cylinder against the
reaction of the spiral spring, and thus passing it without communicating rotation
to the aforesaid cylinder, As there is such a stop motion and driving wheel
attached to an opposite end of each of the cylinders A B, and as the wheels F
are alternately bolted to their respective cylinders, and set free, the table D thus
drives one locked wheel and cylinder when travelling in one direction (the other
driving wheel running free) and the other locked wheel and cylinder on its return
(the first wheel running free); the relative rotation of the two cylinders A B being
maintained throughout by the external geared wheels E E.
I am thus able to apply a crank driving motion H, Figure 1, and epicyclic
wheel h, to produce the reciprocating movement of the "forme" table D, and with
the following adjuncts to obtain at the same time a usual and gradual stop and
start, to the reciprocation, which admits of a high speed of rotation without shock.
In order to obtain the aforesaid easy reversal at bigh speed without shock, and to
prevent the cylinders from overrunning, I preferably check the rotation of the axes
of the cylinders, as that simultaneously checks the movement of the reciprocating
table.
I effect this in the following alternative methods :-
1st I affix a powerful brake K, Figure 1, to the circumference of a wheel keyed
to the axis of one of the cylinders, which is applied at the required moment through
the rocking lever and a suitable cam motion upon the rotary shaft.
2nd In addition to the resistance of the above brake to ensure a more perfect
dead stop of the cylinders, I apply a rod L, Figure 5, to a pin upon a disc or
wheel keyed to one of the cylinder shafts. This rod L is provided with an anti-
friction roller and presses against the surface of a cam M on any rotating shaft of
the machine. The surface of the cam may be so set out that it follows the entire
revolution of the cylinder, and thus may offer any desired check to the rotation of
the cylinders. To prevent the occurrence of dead points in this arrangement, I pre-
ferably, if required, use a double clieck gear as described, the pins being placed at
right angles to one another one at each end of a single cylinder or applied one to
cach of the two geared cylinders.
3rd Alternatively, I key a partially geared wheel N (Figure 6) upon the cylinder
shaft, and cause it to gear into a segment n caused to reciprocate by a rod L', and
cam M³, the form of the cam being such as to check the movement of the rocking
segment as the cylinder wheel N gears into it.
4th Alternatively, I provide a forked rocking rod P, Figure 7, into the fork of
which a pin p upon a disc or wheel koyed to the cylinder shaft, engages, when it is
required to check the momentum of the cylinders. The forked rod P is caused to
oscillate by the rod L", and the cam M"; and the form of the cam is such as to
check the movement of the rod P when the pin of the cylinder engages with it.
The method of driving before described enables me to bring a third and central
roller bearing Q (Figure 2) under the middle of the "forme" table, and thus to give
it a greater rigidity and uniformity of imprint.
To lift the cylinders alternately from the "forme" when not printing, I uso a
motion (shown in detail in Figure 8, and in position on the machine in Fig 1) by
which I greatly reduce the effect of any wear of the lifting cam surfaces upon the
rise of the cylinders Instead of effecting the lift direct by the constant revolution
of a cam of small surface which will soon show the effect of wear, I affix cams V
(Figure 8) of large surface upon the main driving shaft using their reciprocation
to oscillate a rocking shaft R through a small angle by means of a suitable rod S
and anti-friction roller S¹ This small angular reciprocation of the shaft R is utilized
to effect the lift of the cylinders by the throw of an eccentric T, Figures 8 and 1,
upon the said shaft. The said eccentric working in a sliding block t (Figure 1) lifta
the bearings of the cylinders as required. Any wear upon the main cam surfaces
is reduced to an imperceptible amount as affecting the lift of the cylinders,

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1st In a printing machine, printing both sides of the paper with a pair of
cylinders, the coinbination therewith of a pair of fixed cog wheels E E, and a
driving stop and slip wheel F, on each cylinder, gearing into the table racks, to
effect an intermittent rotary motion without reverse in the said cylinders, sub-
stantially as described.
2nd In a double cylinder printing machine as claimed in claim 1, the combination
therewith of a crank and epicyclic driving gear, and a central bearing rail, as and
for the purposes described.
3rd In a printing machine as claimed in claims 1 and 2, the construction of the
cylinder lifting gear substantially as described.
4th In a printing machine as claimed in claims 1, 2 and 3, the combination there-
with of a brake pad applied to the cylinders by cam gear and the following
alternative check gears:-
a) A rod attached to a pin upon a disc or wheel keyed to the cylinder axis and
pressing directly upon the surface of a cam on any rotary shaft.
b) a geared rocking segment engaging into a partially geared wheel on the
cylinder axis, the rocking segment being controlled by cam gear from any rotary
shaft.
c) a forked oscillating rod engaging into a pin upon a disc or wheel keyed to the
cylinder axis, the oscillations of the rod being controlled by cam gear from any
rotary shaft.
5th The combination of all or any part of the preceeding detailed claims to form
a double cylinder printing machine to produce high class printing, with better
impress, better register, loss "slur," and to run without shock at a higher speed
than heretofore, substantially as described.
Dated this 6th day of December 1884