An Improved Pressure Gauge.
Year: 1889

page_text: Date of Application, 14th Dec., 1889
Complete Specification Left, 18th July, 1890-Accepted, 23rd Aug., 1896
PROVISIONAL SPECIFICATION.
An Improved Pressure Gauge.
We, ANATOL SIEGERT and WALTHER DÜRR, both of Munich, in the Empire
of Germany, Engineers, do hereby declare the nature of our invention to be as
follows:-
This invention consists in a device to be used as a pressure gauge for indicating
small variations or differences of pressure. The improved gauge is especially suitable
as a draught indicator for chimneys, flues, and the like or in connection with or as the
indicating part of air tension pyrometer for indicating high temperatures.
The device comprises a closed receptacle containing liquid up to a certain level, a
bell shaped inverted cup or vessel is pivoted or suspended with a pulley-wheel and
counterpoise in said closed receptacle so that the rim of said vessel is sealed by the
liquid aforesaid. A pipe passes into the closed receptacle and extends upward through
the liquid and terminates above the level of the liquid in the space within the inverted
vessel aforesaid, so that said space is brought into free communication with the outer
air in the place where the device is placed or where the outer end of the aforesaid pipe
terminates.
The variations in the external pressure will be communicated to the space within
the vessel aforesaid and the latter will rise or fall accordingly until the pressure is
balanced in the receptacle. This movement of the vessel may be transferred to an
indicating hand, by a toothed segment or rack and pinion or lever mechanism of any
suitable and known description.
Dated this 14th day of December 1889.
HERBERT & Co.,
Agents to Applicants.
COMPLETE
SPECIFICATION.
An Improved Pressure Gauge.
We ANATOL SIEGERT and WALTHER DÜRR both of Munich, in the Empire of
Germany, Engineers, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained in
and by the following statement :-
་
This invention consists in a device to be used as a pressure gauge for indicating
small variations or differences of pressure. The improved gauge is especially suitable
as a draught indicator for chimneys, flues and the like or in connection with or as the
indicating part of air tension pyrometers for indicating high temperatures.
The device comprises a closed receptacle containing liquid up to a certain level, a
bell-shaped inverted cup or vessel is pivoted or suspended with counterpoise in
said closed receptacle, so that the rim of said vessel is sealed by the liquid
aforesaid.
A pipe passes into the closed receptacle and extends upward through the liquid and
terminates above the level of the liquid in the space within the inverted vessel afore-
said, so that said space is brought into free communication with the outer air in
the place where the device is placed or where the outer end of the aforesaid pipe
terminates.
The variations in the external pressure will be communicated to the space within
the vessel aforesaid and the latter will rise or fall accordingly until the pressure is
balanced in the receptacle.
This movement of the vessel may be transferred to an indicating hand, by a toothed

page_text: segment or rack and pinion or lever mechanism of any suitable and known
description.
The apparatus is represented in the annexed drawing in which
Fig. 1 is a front elevation thereof.
Fig. 2 a cross section on line A¹-B¹.
Fig. 3 section on line C-D¹:
A is the cup or vessel partially filled with liquid. bis the pipe which penetrates
air-tight into the cup and extends above the level of the liquid. B is the reversed
bell-shaped vessel, which is suspended either revolvable on the pivots a, or on a
band or the like over a pulley and balanced by suitable counter-weights (Figs. 1, 2
and 3).
The pipe b is carried into the locality where the changes of tension exist which are
to be indicated. As soon as this tension lessens or increases, in comparison to the
surrounding atmosphere, a correspondingly high column of liquid is raised or pressed
down within the bell B and the latter is either encumbered or released thereby. The
immediate consequence of this process is a lowering or raising respectively of the
bell B, which continues for so long until the disturbed balance is equalized again.
This motion may be illustrated either direct by means of an indicator and a dial or by
some other mechanism, such as a ratchet bar or a rack with a ratchet-wheel (as shown
in Figs. 1 and 2) or by precision lever connections and the like.
+
In using the device described as a pyrometer faulty indications will result, if a
longish pipe is to be used with it. In order to remove these faulty indications the
arrangement shown in Fig. 4 may be adopted. In order that the detrimental influence
of the changing state of the barometer may be obviated, the instrument is enclosed
air-tight in a second case a¹.
If is the cylinder, the enclosed air-column of which serves for indicating the
temperature and y is the pipe which leads to the instrument, the faulty indication is
occasioned by its cooling down or heating.
This faulty indication is however excluded by the addition of a second pipe y', which
is of corresponding length and cross-section to the first one and which enters at z into
the outer space of the receiver A, y entering into the bell-shaped B.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
The improved pressure gauge consisting of an inverted hollow vessel sealed in a
liquid, with a pipe or equivalent communication with the interior of said vessel and
indicating devices for showing the movements of the vessel the whole operating
substantially as and for the purpose set forth.
Dated this 18th day of July 1890.
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicants.