IMPROVEMENTS IN PRESSURE GUAGES
Year: 1858

page_text: LETTERS PATENT to William Wallis, William Langford, and James
Slack, of Nottingham, for the Invention of "IMPROVEMENTS IN PRESSURE
GUAGES."
Sealed the 16th July 1858, and dated the 6th May 1858.
PROVISIONAL SPECIFICATION left by the said William Wallis, William
Langford, and James Slack at the Office of the Commissioners of
Patents, with their Petition, on the 6th May 1858.
We, WILLIAM WALLIS, WILLIAM LANGFORD, and JAMES SLACK, of Notting-
ham, do hereby declare the nature of the Invention for "IMPROVEMENTS IN
PRESSURE GUAGES," to be as follows:-
This Invention consists in arranging pressure guages in the following
manner In connection with the boiler or vessel, the pressure in which the
instrument is required to register is a metal cup with a flange at its upper
edge; on this flange a disc of thin sheet brass, of vulcanized india-rubber, or
other suitable material is laid, and over this is a second disc of tempered steel,
in which a number of straight slits are made proceeding radially from the
centre of the disc towards the circumference, and each equal in length to half
the internal diameter of the cup on which the discs are laid. The discs are
kept in their places on the flange of the cup by a metal ring, which rests on
their edges, and is fastened to the flange of the cup by screw bolts passing
through it and the discs. It will be seen that as the pressure in the cup

page_text: increases, so will the sections of the slit steel plate be deflected more and more
from their natural position; and in order to complete the instrument it is only
necessary to connect with one of the sections of the steel plate, apparatus for
indicating the amount of its motion. For this purpose a rod is jointed to one
of the sections of the steel disc near its centre, and this rod gives motion to a
toothed quadrant, so as to cause it partially to revolve on its axis, and in so
doing it drives a pinion on the axis of which a pointer is mounted, which
indicates on a dial the pressure in the boiler or vessel.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Wallis, William Langford, and James Slack in the
Great Seal Patent Office on the 2nd November 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
WALLIS, WILLIAM LANGFORD, and JAMES. SLACK, of Nottingham, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of May, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said William Wallis, William Langford, and James Slack, Her special licence
that we, the said William Wallis, William Langford, and James Slack, our
executors, administrators, and assigns, or such others as we, the said William
Wallis, William Langford, and James Slack, our executors, administrators,
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 Inven-
tion for "IMPROVEMENTS IN PRESSURE GUAGES," upon the condition (amongst
others) that we, the said William Wallis, William Langford, and James Slack,
our executors or administrators, by an instrument in writing under our or
their hands and seals, or under the hand and seal of one of us or them, 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that we, the said William Wallis, William Langford,
and James Slack, do hereby declare the nature of the said Invention, and in

page_text: what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement thereof, that is to say:-
This Invention consists in arranging pressure guages in the following
manner: In connection with the bc ler or vessel, the pressure in which the
instrument is required to register is a metal cup with a flange at its upper
edge; on this flange a disc of thin sheet brass, of vulcanized india-rubber, or
other suitable material is laid, and over this is a second disc of tempered steel,
in which a number of straight slits are made, proceeding radially from the
centre of the disc towards the circumference, and each equal in length to half
the internal diameter of the cup on which the discs are laid. The discs are
kept in their places on the flange of the cup by a metal ring, which rests on
their edges, and is fastened to the flange of the cup by screw bolts passing
through it and the discs. It will be seen that as the pressure in the cup
increases, so will the sections of the slit steel plate be deflected more and more
from their natural position; and in order to complete the instrument it is only
necessary to connect with one of the sections of the steel plate, apparatus for
indicating the amount of its motion. For this purpose a rod is jointed to one
of the sections of the steel disc near its centre, and this rod gives motion
to a toothed quadrant, so as to cause it partially to revolve on its axis, and in
so doing it drives a pinion on the axis of which a pointer is mounted, which
indicates on a dial the pressure in the boiler or vessel.
And in order that our said Invention may be most fully understood and
readily carried into effect, we will proceed to describe the Drawing hereunto
annexed.
DESCRIPTION OF THE DRAWING.
Figure 1 is a front view, and Figure 2 is a vertical section, of a pressure
guage constructed according to our Invention. a is a metal cup, which
communicates by the pipe 6 with the boiler or vessel, the pressure in which
the instrument is required to indicate; c is a disc, of thin sheet brass, of
vulcanized india-rubber, or other suitable material (sheet brass is the material
which I prefer to employ); d is a disc of tempered steel placed over the
disc c; this disc c is shown in plan at Figure 3, and has radial slits cut in it,
as is there clearly shown. The discs c and d are kept in position by screws
e, e, which pass through holes formed round their edges, and clamp them
firmly between the flange of the cup a and the upper ring f, which supports
the dial. To one of the sections of the disc d a rod g is jointed, and this at its
other end is attached, as is shown, to the toothed quadrant h mounted on the
axis i, and the teeth of this quadrant gear with a pinion j, by the axis of

page_text: which the pointer k is carried; thus as the disc d, yields to the pressure
in the boiler or vessel, its motion is communicated to the pointer k, and this
indicates on the dial the amount of this pressure.
In witness whereof, we, the said William Wallis, William Langford,
& James Slack, have hereunto set our hands and seals, this Twenty-
third day of October, in the year of our Lord One thousand eight
hundred and fifty-eight.
Witness,
WILLIAM WALLIS.
(L.S.)
WILLIAM LANGFORD. (L.S.)
JAMES SLACK.
(L.S.)
HAMMOND CHRISTOPHER BROXHOLME,
of Nottingham.