IMPROVEMENTS IN THE CONSTRUCTION OFPRESSURE AND VACUULI GAU
Year: 1856

page_text: LETTERS PATENT to Bernard Augustus Grautoff and Charles Henry
William Albrecht, both of Lime Street Square, in the City of London,
Merchants, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF
"
ection
PROVISIONAL SPECIFICATION left by the said Bernard Augustus Grautoff
and Charles Henry William Albrecht at the Office of the Commissioners
of Patents, with their Petition, on the 28th August 1856.
We, BERNARD AUGUSTUS GRAUTOFF and CHARLES HENRY WILLIAM
ALBRECHT, both of Lime Street Square, in the City of London, Merchants,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF PRESSURE AND VACUULI GAUGES," (communicated to us by a
foreigner residing abroad,) to be as follows:-
Our Invention consists in the particular construction and fitting of springs
which are acted upon by the fluid to be gauged, which springs transmit motion
through a spindle to an indicator or pointer and cause it to indicate upon a
dial. A, A, are two springs of hardened steel, of the particular form shewn in the
Figure; the external edges are made flat, and are hermetically sealed by a brass
or other metal ring clamping the two edges tightly together. In order to pre-
serve the springs from oxidation we cover the inside and outside thereof with a

page_text: solution of caoutchouc or other protective coating, or we so coat the inside only,
and protect the exterior by a thin sheet of brass, platinum, or other metal cor-
responding with the shape of the springs, which sheet metal is bent over the
edge of each spring before the fixing of the clamping ring. The inner edges of
the springs are united at bottom to a plate a, and at top to a nut 6, which is
hollow, to allow of the passage through it of a spindle c, the lower end of which
rests upon the plate a, while the upper end is connected to gear which works
an indicator or pointer. The steam or fluid enters by the passages d, d, into the
box e, in which the springs are contained, and collapsing the springs causes the
spindle c to rise and indicato through the pointer the pressure thereof. We
have just described the apparatus as a pressure guage, and, slightly modified, it
forms a vacuum gauge.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Bernard Augustus Grautoff and Charles Henry William
Albrecht in the Great Seal Patent Office on the 28th February 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, BERNARD
AUGUSTUS GRAUTOFF and CHARLES HENRY WILLIAM ALBRECHT, both of Lime
Street Square, in the City of London, Merchants, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of August, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
Bernard Augustus Grautoff and Charles Henry William Albrecht, Her special
licence that we, the said Bernard Augustus Grautoff and Charles Henry
William Albrecht, our executors, administrators, and assigns, or such others
as we, the said Bernard Augustus Grautoff and Charles Henry William
Albrecht, our executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at 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 THE
CONSTRUCTION OF PRESSURE AND VACUUM GAUGES," (communicated to us by a
foreigner residing abroad,) upon the condition (amongst others) that we, the
said Bernard Augustus Grautoff and Charles Henry William Albrecht, or one
of us, our executors or administrators, by an instrument in writing under our,
or their, or one of our or their hands and seals, should particularly describe

page_text: 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 we, the said Bernard Augustus Grautoff and
Charles Henry William Albrecht, do hereby declare the nature of the said
Invention, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement thereof, reference
being had to the Drawings hereunto annexed, that is to say :-
Our Invention consists in the particular construction and fitting of springs
which are acted upon by the fluid to be gauged, which springs transmit motion
through a spindle to an indicator or pointer, and cause it to indicate upon
a dial.
Figure 1 of the Drawings is a front elevation, and Figure 2 a cross section,
of a pressure gauge constructed according to our Invention; Figure 3 shews
a modification of the same, which forms a pressure and vacuum gauge com-
bined; and Figure 4 is a view, in plan, of the spring we use in connection with
the pressure gauge.
a, a, are two springs of hardened steel, the edges of which are made flat, and
are hermetically sealed by a brass or other metal ring clamping the two edges
tightly together. In order to preserve the springs from oxydation we cover
the inside and outside thereof with a solution of caoutchouc or other protective
coating, or we so coat the inside only, and protect the exterior by a thin sheet
of brass, platinum, or other metal corresponding with the shape of the springs,
which sheet metal is bent over the edge of each spring before the fixing of the
clamping ring. The springs a, a, are placed in the space i, the casing of which
screws on to the part f, f, that supports the dial plate and mechanism for
working the dial and indicator. The inner edges of the springs a, a, are united
at bottom to a plate k, and at top to a nut e, which is hollow, to allow of the
passage through it of a spindle c, the lower end of which rests upon the plate k,
while the upper end is connected to a bell-crank lever g, which is pivoted at f'.
On the long arm of the lever g a toothed sector is formed, which gears into
a toothed pinion m, which is connected to and actuates the needle o. A spring
or springs p is or are used to keep the rod c in contact with the part k. h is
the inlet passage for the gas, air, or vapour. The steam or fluid enters by the
passage h into the case i, in which the springs a, a, are contained, and collapsing
the springs causes the spindle c to rise; or the passage h, may be brought in
connection with a condenser, thus causing the springs a, a, to extend and the
spindle c to fall, which, by means of the mechanism before described, moves the

page_text: pointer on the dial, and indicates the pressure on a double index formed on
the dial; the apparatus will thus become a pressure and vacuum gauge com-
bined, as shewn at Figure 3. The gauge may however be modified, and made
more suitable for vacuum or low-pressure gauges, by the rod c resting on the
centre of the outside of the spring a; the external part of the spring is
surrounded by the atmosphere, and the internal part is subjected to the
pressure without the atmosphere. The centre of the opposite side of the
spring to that on which c rests is fixed to the passages h, h, an opening or
openings connecting the interior of the spring with them, and these passages
lead to a condenser or other vessel in which the vacuum is to be ascertained.
. And having now described the nature of our said Invention, and in what
manner the same is to be performed, we declare that we claim as our improve-
ments in pressure and vacuum gauges the constructing and fitting of springs
made to act and indicate upon a dial the degrees of pressure or vacuum, in the
manner herein-before described.
In witness whereof, we, the said Bernard Augustus Grautoff, and
Charles Henry William Albrecht, have hereunto set our hands and
seals, this Twenty-seventh day of February, One thousand eight hundred
and fifty-seven.
BERNARD AUGUSTUS GRAUTOFF.
(L.S.)
CHARLES HENRY WILLIAM ALBRECHT. (L.S.)