An Automatic Electric Temperature Alarm.
Year: 1890

page_text: Date of Application, 5th Feb., 1890
Complete Specification Left, 5th Nov., 1890-Accepted, 5th Feb., 1891
PROVISIONAL SPECIFICATION.
An Automatic Electric Temperature Alarm.
I MARIE HENRI LÉONIDE BOUGAULT of 48 Rue Leyteire, Bordeaux in the
Republic of France, Manufacturer do hereby declare the nature of this invention
to be as follows :—
This invention consists in a device adapted to be combined with an electric
current generator and suitable bell or signal device for giving an alarm or signal
when the temperature of the place in which the device is rises to or falls below a
certain desired degree of temperature.
The device consists of a box carrying a metallic thermometer operating a rotary
indicator. The face of the box is formed as a dial and provided with a scale of
degrees of temperature around its circumference. A cross bar is pivoted centrally
on this dial and is provided at end with an indicating point so that it may be
accurately adjusted to point to any desired degree on the scale. This end of the
cross bar carries a pivoted metallic plate covered on one side with ivory or other
material non conductive of electricity, the plate being reversible. Suitable connec-
tions are made with the poles of the generator so that an alarm is given when the
rotary indicator touches the pivoted plate on its conductive side which will happen
when the temperature rises or falls respectively to the degree at which the cross
bar is set.
The pivoted plate aforesaid may be replaced by a pivoted reversible
star of radiating plates each plate having a conductive surface on one side and a
non-conductive surface on the other.
Dotal this 5th day of Webruary 189N
HERBERT & Co.,
Agents to Applicant.
COMPLETE SPECIFICATION.
An Automatic Electric Temperature Alarm.
1 MARIE HENRI LEONIDE BOUGAULT of 48 Rue Leyteire, Bordeaux in the
Republic of France, Manufacturer 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 adapted to be combined with an electric
current generator and suitable bell or signal device for giving an alarm or signal
when the temperature of the place in which the device is rises to or falls below a
certain desired degree of temperature.
The device consists of a box carrying a thermometer operating a rotary indicator.
The face of the box is formed as a dial and provided with a scale of degrees of
temperature around its circumference. A cross bar is pivoted centrally on this dial
and is provided at one end with an indicating point so that it may be accurately
adjusted to point to any desired degree on the scale.
This end of the cross bar carries a pivoted metallic plate covered on one side
with ivory or other material non conductive of electricity, the plate being reversible.
Suitable connections are made with the poles of the generator so that alarm is given
when the rotary indicator touches the pivoted plate on its conductive side which
will happen when the temperature rises or falls respectively to the degree at which
the cross bar is set. The pivoted plate aforesaid may be replaced by a pivoted
reversible star of radiating plates each plate having a conductive surface on one
side and a non-conductive surface on the other.

page_text: In the drawing hereto annexed
Fig. 1 is a front elevation and Fig. 2 a side elevation of the apparatus, Figs. 3
and 4 being detail views of a modification.
The exterior surface consists of a dial traversed by a metal pin A which is
operated by a thermometer fastened within the interior of the box. The circum-
ference of the dial is divided into degrees and half degrees on its whole circle as
shown more particularly between 0-5 degrees in the drawing with indications up to
15 degrees below 0 and 45 degrees above, Centigrade measurement.
Between the metallic pin A and the dial but movable and pivoting at the central
axis of the latter is a metal plate B C ending in a block W which allows said plate
to be directed towards any point of the circumference in order to place the point X
in front of the desired degree; the plate is then fixed by a screw D at its
back part.
A pin E fastened to the end B of the plate B C or the block W perpendicular to
said plate carries an oscillating metal plate F and serves as an axle therefor, this
plate is held on the axle by a screw G but it is movable and freely suspended. This
plate F has a surface H covered by a small ivory plate. On removing the screw G
the plate F may be withdrawn and replaced in a reversed position so that the
surface H is at I or vice versa.
At the end C of the movable plate BC is fastened a small metal support U
perpendicular to said plate. This support U is insulated at its base from the metal
plate BC by an ivory plate O. Also the pivot E is insulated at its base by an
ivory plate K. The needle A is insulated likewise from the plate B C and from
the pivot of the thermometer which latter operates the needle A through an ivory
plate T.
The support U is connected to the centre of the needle by a metal rod L kept in
the support U by a screw. The other end of this rod L lies in a small recess
arranged at the centre of the needle in order to leave the latter free to revolve
while the rod remains in contact therewith.
MN are binding screws to hold an electric wire inserted at their base into small
openings in the parts E and U respectively.
An electric current (supplied by any battery) arriving by the wire P follows the
rod L then the needle A so that at the moment when the latter arrives at the degree
at which the point X is placed contact is made with the part F the surface I of
which is of metal, then to the pivot E and to the wire Q and the signal will
operate.
When the part I is touched by the needle on its surface H of ivory no. contact
is made the part F being freely pivoted on its axis it rises itself by the action of
the needle A. in order to give only a slight resistance to the course of the latter and
will fall back into its place in a vertical line as soon as the needle has passed.
The back plate of the apparatus is provided with a block R which can be moved
around the whole periphery of this plate in a small groove Y and can be fastened
by a screw S at the desired point. This block is provided with a ring Z intended
for hanging up the apparatus.
When this apparatus is used in localities where quick changes of temperature are
to be feared, the following modification may be used.
A block A' is arranged to slide round the dial and to be fastened by means of a
binding screw B. To this block is fastened a support C insulated at its base by
an ivory plate D. This support serves as pivot to a movable star provided with
four wings E F G H arranged at right angles and each having a metal
surface a bed and an ivory surface efh. This part kept on its pivot by a
screw I'
may be withdrawn and placed upon the axis in a reversed position.
This device can be used in place of or in addition to the single oscillating
plate F.
The thermometer for moving the needle A. of this apparatus (Figs. 1 and 2)
consists of a liquid such as mercury, glycerine, alcohol etc. contained in a hermetically
closed vessel and by its expansion and contraction operating a piston in the interior

page_text: of this vessel, the rod of which is connected with a rack bar which operates a small
pinion on the shaft of the needle A. These different parts except the needle are
protected by being placed in the interior of the apparatus.
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. The combination of the dial the index A operated by a metallic thermometer,
the plate BC with oscillating contact F and fixed contact bar L and movable
suspension block R substantially as and for the purpose set forth.
2. The combination with the dial the index A. and contact F of the contact
block A and rotary star contact thereon constructed substantially as and for the
purpose set forth.
Dated this 5th day of Navamber 1890
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicant.