Improvements in Thermometric Indicators and Fire Alarms.
Year: 1890

page_text: Date of Application, 9th Dec., 1890
Complete Specification Lef, 2nd Sept., 189'-Accepted, 28th Nov., 1891
PROVISIONAL SPECIFICATION.
Improvements in Thermometric Indicators and Fire Alarms.
1, JEAN BAPTISTE CHARLES DION of 7, Rue de l'Arcade, Paris, France,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
My improvements in thermometric and fire alarms consist more particularly in the
application of a curved metallic spring fixed at its ends so that under dilation by
heat it will necessarily assume a greater degree of curvature and be thereby caused
to make contact for closing an electric alarm and indicator circuit or release a
mechanical alarm when an electric current is not employed.
Reference is to be had to the accompanying drawings forming part of this
Specification which illustrate some of the principal applications of the invention.
Figure 1 is a side elevation, and Figure 2 a plan, of one form of the apparatus.
Figure 3 is a diagram shewing several apparatus arranged in series.
จ
A is the base plate or box and A¹ a top plate forming also a cover to protect the
spring, etc. Upon the base plate A, which is usually made of cast-iron or steel, a
spring E of copper, zinc, or other metal, is fixed by its ends, its middle portion
having a certain initial amount of camber and being free to become still more
curved under dilation by heat, the spring being provided at centre with a contact
st of silver or platinum adapted when the curvature of the spring is thus increased
to make contact with a screw B on the top plate A' (which is mounted on insulated
standards D) and close the circuit through the alarm. P is a screw for regulating
t, initial curvature of spring E. This circuit closer is set to act at any given
temperature by turning the pointer C mounted on the contact screw B over a dial J,
but as in practice it is desirable for the circuit closer to act between two given
degrees of temperature, stop pins F are placed on either side of the pointer, as shewn
in Figure 2, in the positions chosen as the extremes of temperature which are not
to be exceeded. Jis a figured dial adjustable about its centre and fixed by a set-
screw I in a slot I at the point at which the pointer indicates the predetermined
degree of temperature. This adjustable dial when once set, enables the pointer
to be accurately re-set in the event of its becoming displaced from any cause.
Immediately the limit of temperature is attained, the spring E becoming more
bowed by expansion will close the circuit between the terminals H H, sound the
alarm, and also exhibit a number indicating the locality from which the signal
proceeded. For long galleries or rooms, the circuit closers would be placed at
intervals in series on the same wires; or they might be arranged in groups,
according to circumstances.
Figures 4 and 5 represent the circuit closer applied to maximum and minimum
thermometric alarms, the former being also applicable as a fire alarm. The initial
curvature of the spring E towards the contact D in the case of a circuit closer for
operating at a maximum and away from it in the case of a closer for operating at a
minimum temperature, as shewn in Figures 4 and 5 respectively, is adjusted
according to the degree of temperature at which the alarm is to operate by shifting
the sliding block K by means of screw P having a pointer C (Figure 6) which
moves over a dial J graduated in thermometric degrees. In Figure 1 this adjust-
ment was made by the contact screw; in the present case. the contact D is fixed
and is insulated from whilst the spring E is in electric connection with the base A.
In Figure 8 the contact D is adjusted by a lever. In Figures 9, 10, 11, it
consists of a sleeve N on the insulated terminal screw H placed beneath the
spring E whose curvature is adjusted by means of screw P, as before.

page_text: Figure 12 represents the circuit closer adapted when enclosed in a metal casing to
be placed in a coal bunker, silo, fodder store, etc.
Figure 13 shews the device adapted to close the circuit both at maximum and
minimum temperatures. In Figure 14, two springs are used.
Figures 15 and 16 are similar to Figures 4 and 5.
Figure 17 shews a combined fire alarm and electric bell push.
Figures 18 and 19 represent various arrangements of the springs.
Figure 20 shows the spring as an ordinary temperature indicator or thermometer.
The device shewn in Figure 12 is composed of two bars A A separated at the
middle and bound together at the ends with insulating material B between, by
screws C or ferrules D, the ends of spring E being fixed and butting in recesses
formed in one of said bars. The spring makes contact, as before, with a screw G
provided with a pointer I above a dial plate H by which the contact can be adjusted
as before. Or, instead of a screw, a second oppositely-curved spring may be
employed, as shewn in Figure 14, the adjustment being effected by regulating the
distance between the parts of the frame in which the springs are fixed, by means of
an adjusting screw at one end.
According as the circuit is closed by the contact of the convex or the concave
side of the spring, the closer is adapted to act at a maximum or at a minimum
temperature respectively, and in Figure 13 it fulfils both functions, there being a
contact at both sides of the spring adjustable by micrometer screws G graduated in
thermometric degrees and set to indexes I. The spring is fixed to posts J of which
one is coupled by a metal strip K to terminal F whilst the contacts G are mounted
in studs respectively connected with the terminals F1 and F" corresponding
respectively with the maximum and minimum alarms. In Figure 17 the spring has
a knob to adapt it for use as an electric bell push. Several springs may be
combined, as shewn in Figures 18 and 19, either concave or convex and acting either
simultaneously in the same or opposite directions.
Figure 20 shews the spring applied for the purposes of an ordinary thermometer,
the effects of expansion being indicated by a pointer A actuated through an arm D
by the curved spring B fixed at the ends C, the pointer A ranging over a graduated
plate E between the points M and N as the spring expands or contracts under the
variations of temperature.
Dated this 9th day of December 1800.
J. B. C. DION,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Thermometric Indicators and Fire Alarms.
I, JEAN BAPTISTE CHARLES DION of 7 Rue de l'Arcade, Paris, France,
Electrical 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 improvements in thermometric fire alarms and indicators consist more
particularly in the application of a curved metallic spring fixed at its ends so that
under dilation by heat it will necessarily assume a greater degree of curvature, the
effect being increased in the ratio of the versed sine to the chord of the arc and be
thereby caused to make contact for closing an electric alarm and indicator circuit,
or release a mechanical alarm when an electric current is not employed.
Reference is to be had to the drawings accompanying my Provisional Specification
which illustrate some of the principal applications of the invention.
Figure 1 is a side elevation, and Figure 2 a plan, of one form of the apparatus.
Figure 3 is a diagram shewing several apparatus arranged in parallel.
A is the base plate or box and A¹ a top plate forming also a cover to protect the

page_text: spring, etc. Upon the base plate A, which is usually made of cast-iron or steel, a
spring E of copper, zinc, or other metal, is fixed by its ends, its middle portion
having a certain initial amount of camber and being free to become still more
curved under dilation by heat, the spring being provided at centre with a contact
stud G of silver or platinum adapted when the curvature of the spring is thus
increased to make contact with a screw B on the top plate A' (which is mounted on.
insulated standards D) and close the circuit through the alarm. P is a screw for
regulating the initial curvature of spring E. This circuit closer is set to act at
any given temperature by turning the pointer C mounted on the contact screw B
over a dial J, but as in practice it is desirable for the circuit closer to act between
two given degrees of temperature, stop pins F are placed on either side of the
pointer, as shewn in Figure 2, in the positions chosen as the extremes of temperature
which are not to be exceeded. J is a figured dial adjustable about its centre and
fixed by a set-screw 1' in a slot I at the point at which the pointer indicates the
predetermined degree of temperature. This adjustable dial when once set, enables
the pointer to be accurately re-set in the event of its becoming displaced from any
cause. Immediately the limit of temperature is attained, the spring E becoming
more bowed by expansion will close the circuit between the terminals H H, sound
the alarm, and also exhibit a number indicating the locality from which the signal
proceeded. For long galleries or rooms, the circuit closers would be placed at
intervals say at every ten yards in parallel, on the same wires; or they might be
arranged in groups, according to circumstances.
Figures 4 and 5 represent the circuit closer applied to maximum and minimum
thermometric alarms, the former being also applicable as a fire alarm. The initial
curvature of the spring E, towards the contact D in the case of a circuit closer for
operating at a maximum and away from it in the case of a closer for operating at a
minimum temperature, as shewn in Figures 4 and 5 respectively, is adjusted
according to the degree of temperature at which the alarm is to operate by shifting
the sliding block K by means of screw P having a pointer C (Figure 6) which
moves over a dial J graduated in thermometric degrees. In Figures 1 and 7 this
adjustment was made by the contact screw B; in the present case the contact D is
fixed and is insulated from, whilst the spring E is in electric connection with the
base A.
Figure 8 shows a circuit closer in which the spring E is connected by a jointed
link with a contact lever I by which the range of motion of the spring is
multiplied.
it, y
Figures 9, 10 and 11 show respectively a plan, elevation and cross section on
line of a circuit closer in which the contact consists of a stud G and of a
metallic sleeve N on the insulated terminal screw H placed beneath the spring E
whose curvature is adjusted by means of screw P, as before, the spring E being in
electrical contact with the terminal E¹.
Figure 12 represents the circuit closer adapted when enclosed in a metal glass or
other casing to be placed in a coal bunker, silo, fodder store, hothouse &c., to serve
as a temperature indicator.
Figure 13 shews the device adapted to close the circuit both at maximum and
minimum temperatures. In Figure 14, two oppositely curved springs are used.
Figures 15 and 16 show devices similar to Figures 4 and 5 and adapted for use
in the manner indicated for Figure 12.
Figure 17 shows an edge view and underside plan of a spring E such as shown in
Figure 12, provided with a push button so as to enable the instrument to serve
both as a fire alarm and electric bell.
Figures 18 and 19 represent various arrangements of the springs shown in Figure 14
that is to say in which the springs are placed crosswise, instead of coinciding in
direction throughout their whole length as in said figure.
Figure 20 shews the spring as an ordinary temperature indicator or thermometer.
The device shewn in Figure 12 is composed of two bars A A separated at the
middle and bound together at the ends with insulating material B between, by

page_text: screws C or ferrules D, the ends of spring E being fixed and butting in recesses
formed in one of said bars. The spring makes contact, as before, with a screw G
provided with a pointer I above a dial plate H by which the contact can be
adjusted as before. Or, instead of a screw, a second oppositely-curved spring may
be employed, as shewn in Figure 14, the adjustment being effected by regulating
the distance between the parts of the frame in which the springs are fixed, by means
of an adjusting screw at one end.
According as the circuit is closed by the contact of the convex or the concave
side of the spring, the closer is adapted to act at a maximum or at a minimum
temperature respectively, and in Figure 13 it fulfils both functions, there being a
contact at both sides of the spring adjustable by micrometer screws G graduated
in thermometric degrees and set to indexes I. The spring is fixed to posts J of
which one is coupled by a metal strip K to terminal F whilst the contacts G are
mounted in studs respectively connected with the terminals F1 and F corresponding
respectively with the maximum and minimum alarms. In Figure 17 the spring has
a knob to adapt it for use as an electric bell push. Several springs may be
combined as shown in Figures 18 and 19, either concave or convex and acting either
simultaneously in the same or opposite directions.
Figure 20 shows the spring applied for the purposes of an ordinary thermometer
the effects of expansion being indicated by a pointer A pivoted at a and actuated
through an arm D connected to the pointer by a stud and slot, from the curved
spring B fixed at the ends C, the pointer A ranging over a graduated plate E
between the points M and N as the spring expands or contracts under the variations
of temperature.
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.
1st. The herein described thermometric fire alarms and indicators combining
great sensitiveness with facility of adjustment.
2nd. A thermometric fire alarm or indicator consisting essentially of one or more
curved dilatation strips or springs fixed at the ends as herein described, whereby
the effect is increased in the ratio of the versed sine to the chord of the arc, thus
ensuring perfect contact for closing an electric circuit or releasing a mechanical
alarm, as specified.
3rd. Arranging the circuit closers at intervals in parallel upon the same wires, as
and for the purpose specified.
Dated this 2nd day of September 1891.