Improvements in Thermometers and similar Instruments Constructed with Colled Bourdon Tubes.
Year: 1892

page_text: Date of Application, 12th May, 1892
Complete Specification Left, 10th Feb., 1893-Accepted, 15th Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements in Thermometers and similar Instruments Constructed
with Colled Bourdon Tubes.
I, JULES RICHARD, of No. 8 Impasse Tessart, Paris, France, Engineer, do
hereby declare the nature of this invention to be as follows:-
My invention relates to an improved mode of applying coiled tubes of flattened
section, known as "Bourdon" tubes, to thermometers and similar instruments; it
consists mainly in connecting what is usually the free end of the coiled tube to the
end of a lever arm that is fixed on a spindle passing centrally through the coiled
tube, so that by the expansion and contraction of the coil a rotary motion is
imparted to the said spindle in one direction or the other, which is thus made to
actuate the pointer of the thermometer through suitable gearing. For this purpose
according to one construction the coiled Bourdon tube filled with suitable fluid is
arranged vertically and has its one end fixed to a vertical tubular stem that passes
partially through the coil, so that the free end of the latter extends beyond the
open end of such tubular stem. The upper end of the latter is fixed to a cylindrical
casing carrying the dial and index of the thermometer, the axis of the latter being
geared in the known manner to a lever that engages with a forked arm on a spindle
that passes centrally down the tubular stem, in which it is suitably supported by
bearings and resting with its lower end on the point of a screw carried by a
bracket fixed to the lower end of the tubular stem. Below the end of the latter
the spindle has a horizontal lever arm fixed to it which is connected by a link to
the free end of the coiled tube; so that as this is moved by the contraction and
expansion of the coil, the spindle is turned as above described.
According to another arrangement, the coiled tube is arranged with its axis
horizontally, or parallel to that of the dial casing, and the central spindle, which is
also horizontal, carries in addition to the lever arm connecting it to the free end
of the coil, a second arm which is connected to one end of a rod passing up into the
dial casing, and having its other end connected to the lever that is geared to
the pointer.
Dated this 12th day of May 1892.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Thermometers and similar Instruments Constructed
with Coiled Bourdon Tubes.
I, JULES RICHARD of No. 8 Impasse Tessart, Paris, France, Engineer 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 :-
My invention relates to an improved mode of applying coiled tubes of flattened
section, known as "Bourdon tubes " in constructing thermometers and similar
instruments such as pressure gauges. It consists mainly in connecting what is
usually the free end of the coiled tube to the end of a lever arm fixed on a spindle
which passes. centrally through the coil, so that expansion or contraction causes
the spindle to turn in the one direction or the other, thus actuating an index
through suitable gearing.
Fig. 1 of the accompanying drawings is a front view, Fig. 2 is a sectional back
D77

page_text: view with cover removed and Fig. 3 is a sectional plan of a thermometer according
to my invention.
The flattened tube T, charged with liquid and coiled in several convolutions,
has its one end a connected by an arm b to a tube A which is fixed to the casing of
the instrument. The other end c of the tube is connected to an arm d fixed on a
spindle B, which is pivotted on the point of a screw e in a bracket f, and extends
centrally through the tube A, passing through a hole g in a cap / which closes the
tube A. The upper end of the spindle B moves an index X by any known
connection as for instance by means of a forked arm k engaging the finger 1 of a
toothed segment m which gears with a pinion on the axis o of the index.
With this arrangement the action of the instrument is very certain and regular.
According to another arrangement shewn in Fig. 4, the tube T is coiled round a
stationary central support A to an arm b of which is fixed one end a of the tube.
The other end c of the tube is fixed to an arm d on a spindle B which acts on the
axis of the index through an arm o, link p, arm q and toothed segment m and
pinion.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :
1. In a thermometer or similar instrument, mounting a coiled Bourdon tube with
its free end fixed to an arm on a spindle passing centrally through the coil,
substantially as described with reference to Figs. 1, aud 3.
3. The modified arrangement in which the axis of the coil is parallel to that of
the index, substantially as described with reference to Fig. 4.
Dated thie 0th day of February 1803
ABEL & IMRAY,
Agents for the Applicant.