IMPROVEMENTS IN PRINTING MACHINES
Year: 1882

page_text: LETTERS PATENT to Thomas Galloway Dawson and Jeremiah Dawson, of
Otley, in the County of York, Printers' Engineers, for an Invention of
"IMPROVEMENTS IN PRINTING MACHINES,"
PROVISIONAL SPECIFICATION left by the said Thomas Galloway Dawson
and Jeremiah Dawson at the Office of the Commissioners of Patents on
the 25th January 1882.
"
THOMAS GALLOWAY DAWSON, and JEREMIAH DAWSON, of Otley in the County
of York, Printers' Engineers. IMPROVEMENTS IN PRINTING MACHINES.
"
This invention relates to that class of printing machines wherein the impression
cylinder has an intermittent rotary motion, but more particularly to what is known
as "Dawsons Wharfedale Machine and consists of an improved automatic
apparatus for stopping the cylinder at every alternate revolution of the machine or
for an indefinite period by hand, without stopping the other parts of the machine.
We mount a bell crank lever to the frame of the machine and couple the said
lever to a vertical bar and pawl in such manner, that, when the pawl is liberated
the end of the same will be in position to fit into an indentation formed in a
weighted swivel plate that is jointed to a reciprocating bar, which on moving in
the direction actuates the before mentioned bell crank lever and vertical bar,
thereby stopping the impression cylinder, feeding board, printing apparatus, and
grippers until the pawl is placed back in its original position.
The before mentioned pawl is put in or out of gear with the swivel plate, by a
weighted lever actuated by two cams which are so arranged that one can be
actuated by hand, whilst the other is provided with ratchet teeth, or projecting
pins and is actuated by a reciprocating catch rod actuated by the before mentioned
reciprocating bar, or other moving part of the machine. At each stroke of the
reciprocating bar or other moving part of the machine, the catch rod moves the cam
a suitable distance putting the pawl in or out of gear according to the position in
which the cam is turned.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Galloway Dawson and Jeremiah Dawson in the Great Seal
Patent Office on the 24th July 1882.
THOMAS GALLOWAY DAWSON and JEREMIAHI DAWSON, of Otley in the County
of York, Printers' Engineers. IMPROVEMENTS IN PRINTING MACHINES.
This invention relates to that class of Printing Machines wherein the impression
cylinder has an intermittent rotary motion, but relates more particularly to what
is known as "Dawsons' Wharfedale Machine," and consists of an improved automatic
apparatus for stopping the impression cylinder at every alternate revolution of the
same, or for an indefinite period by hand or foot without stopping the other parts
of the machine.
In carrying out our invention, we mount a bell crank lever on a shaft supported
by the frame of the machine, and couple the said lever to a vertical bar and pawl
in such a manner that when the pawl is liberated, the end of the same will be in
a position to fit into an indentation formed in a weighted swivel plate, that is
jointed to a reciprocating bar: on moving this bar in one direction, the before
mentioned bell crank lever and vertical bar are actuated, thereby stopping the
impression cylinder, feeding board, pointing apparatus, and grippers, until the
pawl is placed back in its original position.
The before mentioned pawl is put in or out of gear with the swivel plate, by a
weighted lever-actuated-by-two-cams,-which-arc-so-arranged, that one_cam_can_be
actuated by hand, and the cylinder thereby stopped for an indefinite period, whilst
tho other cam is provided with ratchet teeth or projecting pins, and is actuated
automatically by a reciprocating catch rod, attached to the before mentioned
reciprocating bar or other moving part of the machine. The catch rod moves the
automatic cam a suitable distance putting the pawl in or out of gear with the
swivel plate, according to the position in which the cam is turned, and thus
the cylinder and parts before mentioned are stopped at each alternate stroke of the
reciprocating bar.
In order that our said invention and the manner of performing same may be
better understood, we have hereunto appended one sheet of drawings marked with
letters of reference to be hereinafter referred to, and all parts of the machine not
necessary for the elucidation of these improvements aro omitted in the drawings,
being the same as in ordinary machines.
Figure 1 is a side elevation of a portion of a "Dawson's Wharfedale Printing
Machine" with our improvements attached.
The cam A, reciprocating bar B, bell crank lever C, vertical bar D, and pawl E,
are shown as in common use.
Hitherto at each revolution of the cam A, the end of the reciprocating bar B,
has pressed direct on to the end of the pawl E to stop the impression cylinder and
other parts before described, and the pawl has also been moved in and out of gear
by hand.
By our invention, the pawl E is operated upon by the weighted lever G, which
is carried by the fulcrum F, and actuated by the cam H acting upon the bowl M
attached to lever G, thereby raising the lever G, and allowing the pawl E to drop;
when the swells of cam H come in contact with the said bowl, and when the
cam H is turned to the position that the bowl M lowers into the recess between
the projections of cam H, the pawl E is raised clear of the swivel plate J'.
The swivel plate J' being jointed to the end of the reciprocating bar, allows the
heavy end of pawl E to be lowered at any time without doing damage to the

page_text: machine. If the pawl be lowered, and the end of same come in contact with the
swell J above the recess or indentation J in swivel plate; the latter will turn on
its centre pin C, allowing the reciprocating rod B to move forward without doing
damage to the machine.
The cam H is operated upon by the catch rod K, which is jointed to the
reciprocating bar B, to which motion is imparted by the cam A. The cam H is
loose on shaft S, and is provided with a number of projecting pins L, by means of
which, and the catch rod K working in the manner as beforo described, an inter-
mittent rotary motion is given to the said cam, thereby lifting the weighted
lever G at every alternate revolution of the cam A, by means of the swells of the
cam H acting upon the bowl M.
When the weighted lever G is lifted, the same allows the heavy end of pawl E
to fall into the position as shewn on drawing, ready for the forward stroke of the
reciprocating bar B: the recess or indentation J in swivel plato J, which is also
jointed to the end of reciprocating bar, then presses against the end of pawl E,
causing the same to move in the direction of the arrow, thereby moving the bell
crank lever C, and shaft S, raising the vertical bar D, and stopping the cylinder R
and other parts of the machine before mentioned.
The weighted lover G is extended at G¹ beyond the fulcrum F, by which means
the attendant can stop the cylinder and other parts for an indefinite period by
pressing down with his foot the extended part, which allows the pawl E to drop
into the position as shewn on drawing to be acted upon by the swivel plate J',
when the cylinder will romain stopped until the lever is released.
In order to stop the impression cylinder for an indefinito period by hand, we
mount a cam H', and handle N, on the short shaft Q, passing through and carried
by frame of machine. By means of this cam, we are enabled to lift the bar T, and
weighted lever G; allowing the pawl E to drop into the position before described
for stopping the cylinder.
In certain kinds of work it is not necessary to have the impression cylinder
stopped: in such cases the catch rod K is lifted out of gear with the cam H, by
means of an eccentric or short arm P, acting on the underside of catch rod as shewn
in detail drawing Figure 2.
What we claim as our invention is :—
The combination of the reciprocating bar B and swivel plate J' with pawl E,
arranged substantially in the manner and for the purpose as herein before described
and illustrated by the accompanying drawings.
The combination of the weighted lever G with the pawl E arranged substantially
in the manner and for the purpose as herein before described and illustrated by tho
accompanying drawings.
The combination of the reciprocating rod B and catch rod K with cam H
substantially for the purpose described.
In witness whereof I the said Thomas Galloway Dawson for and on behalf
of myself and the said Jeremiah Dawson have hereunto set my hand and
seal this 22nd day of July in the year of our Lord One thousand eight
hundend and mirchin town