IMPROVEMENTS IN MAINTAINING, CONTROLLING, AND REGISTERING THE PRESSURE IN HYDRAULIC PRESSES, AND IN APPARATUS CONNECTED THEREWITH. SP
Year: 1870

page_text: LETTERS PATENT to Francis Virtue, of Liverpool Oil Mills, Liver-
pool, in the County of Lancaster, for the Invention of "IMPROVEMENTS
IN MAINTAINING, CONTROLLING, AND REGISTERING THE PRESSURE IN HYDRAULIC
PRESSES, AND IN APPARATUS CONNECTED THEREWITH.
PROVISIONAL SPECIFICATION left by the said Francis Virtue at the
Office of the Commissioners of Patents, with his Petition, on the
16th March 1870.
I, FRANCIS VIRTUE, of Liverpool Oil Mills, Liverpool, in the County
3 of Lancaster, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN MAINTAINING, CONTROLLING, AND REGISTERING THE PRESSURE
IN HYDRAULIC PRESSES, AND IN APPARATUS CONNECTED THEREWITH,'
to be as
follows:-
"
My Invention relates to the working of a number of hydraulic presses
with but one safety valve standing apart from the pumps, and so
arranged and combined with the pressure guage that the latter is made
to serve the double purpose of registering and of assisting the safety
valve in preventing excessive pressure.

page_text: In carrying out my Invention I attach to hydraulic presses a safety
valve of the common construction, but cast in connection with a check-
valve case. This case is placed in communication with each of the press
cylinders by means of a pipe, all of which pipes are provided with suit-
able valves, and lead into one main passage in the check-valve case
controlled by the safety valve before mentioned. The liquid under
pressure in the cylinders rises in the pipes in connection therewith
through the valves in the casing into the main passage, which is also
placed in communication with a pressure guage. All the superabundant
liquid forced into the several cylinders is thus caused to pass through
the one safety valve, which serves to control the pressure in the whole
of the cylinders employed. To the pressure guage indicator I attach a
vertical rod provided at its upper part with an adjustable crosshead
which is raised with the guage indicator as the pressure increases. On
being raised to a certain height (the pressure in the cylinders having
then attained the limit desired) the crosshead will come into contact
with and raise the end of a lever arm working in connection with
the end of the safety valve lever which will thus be raised, and the valve
opened to prevent the accumulation of pressure. Near the lower part
of the pressure guage, and towards one side, I mount a small cylinder
or barrel to revolve on a vertical axis carried on a suitable bracket.
This barrel is provided with pawl and ratchet gear actuated by the aid
of a cord or line attached to the pawl, and passing over pulleys to one of
the press boxes to which said cord is attached. In this manner the
pawl will be operated, and the barrel caused to revolve one tooth at each
raising and lowering of the press boxes. To the circumference of thic
revolving barrel I attach a properly prepared paper provided with a scale
corresponding with the one marked on the guage.
The guage itself I
provide with a jointed socket carrying a pencil, which, as the pressure
increases, is raised with the guage, and marks on the paper a vertical line
corresponding in height with the rise of the indicator of the guage, so
registering on the paper the pressure attained.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Francis Virtue in the Great Seal Patent Office on
the 16th September 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCIS
VIRTUE, of Liverpool Oil Mills, Liverpool, in the County of Lancaster,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of March, in the year of
our Lord One thousand eight hundred and seventy, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Francis Virtue, Her special licence
that I, the said Francis Virtue, my executors, administrators, and assigns,
or such others as I, the said Francis Virtue, my executors, adminis-
trators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed', should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN MAINTAIN-
ING, CONTROLLING, AND REGISTERING THE PRESSURE. IN HYDRAULIC PRESSES, AND
IN APPARATUS CONNECTED: THEREWITH," upon the condition (amongst others)
that I, the said Francis Virtue, my executors or administrators, by an in-
strument in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Francis Virtue, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Sheet of Drawings here-
unto annexed, and to. the letters and figures marked thereon (that is
to say)
My Invention relates to the working of a number of hydraulic presses
with but one safety valve standing apart from the pumps, and so arranged
and combined with the pressure guage, that the latter is made to serve
the double purpose of registering, and assisting the safety valve in pre-
venting excessive pressure.

page_text: In carrying out my Invention I attach to hydraulic presses a safety
valve of the common construction, but cast in connection with a check
valve case.
This case is placed in communication with each of the
press cylinders by means of a pipe, all of which pipes are provided with
suitable check valves to prevent the return of the liquid through any one
of them and lead into one main channel in the check valve case con-
trolled by the safety valve before mentioned. The liquid under pressure
in the cylinders rises in the pipes in connection therewith through the
valves in the casing into the main passage which is also placed in com-
munication with the pressure guage. All the superabundant liquid
forced into the several cylinders is thus caused to pass through the one
safety valve which serves to control the pressure in the whole of the
cylinders employed. To the pressure guage indicator I attach a vertical
rod provided at its upper part with an adjustable crosshead which is
raised with the guage indicator, as the pressure increases. On being
raised to a certain height (the pressure in the cylinders having then
attained the limit' desired) the crosshead will come in contact with and
raise the end of a lever arm working in connection with the end of the
safety valve lever, which will thus be raised and the valve opened to
prevent the further accumulation of pressure. Near the lower part of
the pressure guage and towards one side I mount a small cylinder or
barrel to revolve on a vertical axis carried on a suitable bracket. This
barrel is provided with pawl and ratchet gear actuated by the aid of a
cord or line attached to the pawl and passing over pulleys to one of the
press boxes to which said cord is attached. In this manner the pawl
will be operated and the barrel caused to revolve to the extent of one
tooth at each raising and lowering of the press boxes. To the circum-
ference of the revolving barrel I attach a properly prepared paper
provided with a scale corresponding with the one marked on the guage.
The guage itself I provide with a jointed socket carrying a pencil,
which, as the pressure increases is raised with the guage and marks
on the paper a vertical line corresponding in height with the rise of
the indicator of the guage so registering on the paper the pressure

page_text: A is the check and safety valve casing cast in one mounted on
suitable framing and standing apart from the pumps; B is a safety valve
of the ordinary construction; and C, C, check valves for controlling
the passage of liquid in pipes D, D, D, D, by which all the press.
cylinders communicate with the casing A and safety valve B. There
are four tubes D, and consequently four cylinders in the present instance,
although a greater number may be controlled by the same safety valve B
if required. The pipes D all open into one main channel E leading to
the safety valve B, into which channel the liquid under pressure in the
cylinders rises through pipes D, the check valve C being provided to
prevent the backward passage of any liquid through either of the tubes D
in the corresponding cylinder of which the pressure is let down or
which is not in action. The channel E also communicates with a
vertical pressure guage F Figure 2 by a pipe G conveying the liquid to
the guage (the construction of which forms no part of my Invention) to
indicate the pressure exerted thereon; C¹ are screw plugs inserted in the
holes in casing A, through which valves C are introduced and adjusted
as required to limit the rise of said valves from their seats.
In order to combine the action of the guage with that of the safety
valve to assist the latter in controlling the pressure in the cylinder I
attach a vertical rod H to the indicator I of the pressure guage. In the
guage shown the rod H passes up through the centre of its spring but
without contact therewith or with the casing of the guage. The rod H
is surmounted by a crosshead J screwed thereon which is raised with
the guage indicator as the pressure increases. K is a lever arm
mounted on a fixed fulcrum at L, and resting on an adjustable support M
on the guage case, with its free end over and in line with the rod H
and crosshead J. This lever arm K is connected as shown with the
extremity of the safety valve lever N which is weighted as usual. When
the indicator I is raised to a certain height or indicates the pressure to
which it is desired to limit the liquid in the cylinders the crosshead J
which rises with it, as shown in red lines, will come in contact with and
raise the end of lever K and with it the safety valve lever N, thus
assisting to open the safety valve B at the desired moment to prevent
the further accumulation of pressure. The cross head J is so attached
to stem H that it may be adjusted to raise lever K immediately the
limit of pressure required in the cylinder is attained, so that the
movements of the levers K, N, were they independent, would be as

page_text: nearly synchronous as possible. These levers being connected the
pressure on the guage will thus aid in opening the safety valve at the
right moment, ensuring the correct action of the latter and a uniform
pressure in the cylinders at each compression. I may, however, dispense
with lever K and its connection by disposing the pressure guage so that
the crosshead J may act directly on the extremity of the safety valve
lever N for the purpose above mentioned.
The automatical registration for subsequent reference of the pressure
attained at each compression of the presses is effected by the following
arrangement :-A small cylinder or barrel O is disposed opposite the
pressure guage scale on a vertical spindle carried on a bracket P fixed
to the guage case. The circumference of this barrel is enveloped by a
paper lined or marked with a scale coinciding with the ordinary scale
attached to the guage. To the indicator I of the latter an arm R is
attached jointed at S, and provided at its extremity with a socket
carrying a pencil or marker T, which is held by a spring in contact with
the scale-marked paper on the barrel. The arm R and pencil rise with
the indicator as the pressure increases, marking on the paper a vertical
line corresponding in height with the rise of the indicator I. A
permanent record of the pressure attained is thus made, the paper being
shifted at each compression so as to present a fresh surface to the pencil.
For this purpose the barrel, which is capable of being rotated on its
spindle with slight friction, has attached to its base a ratchet wheel U
which is acted on by a spring pawl V to rotate the barrel. This pawl
shown more clearly in detail views, Figures 3 and 4, is connected by a
universal joint to one limb of a lever W mounted on a fixed fulcrum
carried on bracket P, to the other limb of which lever a line or cord W¹
is attached. This line passes over pulleys W' to a suitable projection on
one of the press boxes, to which it is also connected, so that the pawl
will be operated by the lifting of lever W, and rotate the barrel O to the
extent of one tooth of the ratchet U, at each rise and fall of the press.
X is a spring for drawing back pawl V by lowering lever W with which
it is connected by a screwed stem X' as shown. The nut Z against which
the spring bears is adjusted for regulating the throw of the pawl V.
V', spring for keeping pawl up against ratchet U.
Having described the nature of my Invention, and the manner of
performing the same, I declare that what I claim as my Invention to be
protected by the herein-before in part recited Letters Patent is,-

page_text: 1st. Controlling the pressure in a number of hydraulic presses by a
single safety valve combined with check valve apparatus, arranged and
applied substantially as herein-before described and shown in Figure 1
of the Drawings.
2ndly. Controlling the action of the safety valve by the aid of the
pressure guage acting cither directly on the safety valve lever or through
connections, as shown and described.
3rdly. I claim the application to the indicator I of the guage shown
of a rod H with an adjustable crosshead J acting on the lever K, or
directly on the safety valve lever N, as and for the purpose specified.
4thly. I claim the combination with the indicator I of the guage of an
arm and pencil for marking or recording the position of the indicator,
as described.
5thly. I claim the apparatus for shifting the paper to be marked,
arranged and operating substantially as described and shown in Figures 3
and 4 of the Drawings.
In witness whereof, I, the said Francis Virtue, have hereunto
set my hand and seal, this Thirteenth day of September, in
the year of our Lord One thousand eight hundred and seventy.
F. VIRTUE. (L.S.)