Improvements in Automatic Fire Alarms.
Year: 1894

page_text: Date of Application, 23rd June. 1594
Complete Specification Left, 2:st Mar., 1895-Accepted. 27th Apr., 1895
[Communicated from abroad by ASHBEL T. WALL and GEORGE A. WALL, both
of Providence, in the State of Rhode Island, United States of America,
Manufacturers.]
Improvements in Automatic Fire Alarms.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, do hereby declare
the nature of this invention to be as follows:-
:-
The purpose of the invention is first to make it more certain that a circuit closer
when operated after long disuse shall effectually close the circuit, and secondly, to
make it certain that electrical apparatus, intended to give an automatic alarm
when a given temperature is reached in the neighbourhood of a thermostat shall
always be in working order.
The first fenture of the invention is an automatic circuit closer composed of the
following parts a spring coiled about its inner support, and connected to one
electrode of the circuit; suitable means to hold one of its ends when the spring is
under tension; and an electrode connected to the other pole of the circuit, and out
of contact with the spring when under tension, but so placed as to limit the side-
wise motion of the spring and permit its end wise motion, when the spring is
released; the main feature being that the spring when released moves sidewise
until it comes into contact with the electrode, and then moves end wise scraping and
rubbing over the electrode; thereby not only ensuring contact between the spring
and the electrode, but also ensuring such a scraping or rubbing of the surface of
the spring over the surface of the electrode as to make sure of an effectual electric
contact between the two.
In general the spring will be held under tension by soldering its end to some part
of the case of the instrument with solder whose melting point is such that it will
high
melt and release the spring when the temperature about the instrument
enough; but obviously this, the first feature of the invention is not limited to
that kind of circuit closers, called thermostats, set in operation by a rise of
temperature.
Another advantage of this feature of my invention is that the spring will
operate successfully with two electrodes, so that the circuit closer may be used to
close two circuits, and I make it, preferably with three electrodes, from two of which
the spring is kept out of contact when under tension.
The second feature of my invention is an automatic fire alarm system comprising
the following features; viz.: A closed circuit and its translating device or devices;
an open circuit and its translating device or devices; a thermostat with three
electrodes; and a loop circuit containing a rheostat and connecting two of the
three electrodes of the thermostat; the third electrode of the thermostat
forming a part of the open circuit.
The use of thermostats in systems for guarding property against fire by giving
an alarm automatically as soon as any thermostat is exposed to a predetermined
temperature has long been known but owing to the fact that the apparatus is
likely to remain unused for long periods of time and to the further fact that it is
likely to get out of order before the occasion arises for its operation, its use has
been much restricted. The object of this feature of the present invention is to

page_text: provide a system of this kind which will give notice automatically when it is out of
order, whether from accident or design and generally to make the use of
thermostate as automatic fire alarms so certain and efficient that full confidence
can be reposed in such a system in spite of the fact that no occasion for its operation
as a fire aların may arise for years after it is constructed.
When the temperature rises sufficiently at any one of the thermostats the solder
holding the spring melts and the spring uncoils thereby electrically connecting all
three of the electrodes; and the result is that the loop and rheostat of the closed
circuit is cut out, and the open circuit is closed, and this gives two alarms one alarm
being given by the translating device of the closed circuit, the other by the translating
device of the normally open circuit; and in practice the translating device of each
closed circuit is under the charge of an attendant, at for example a central or main
office, while the translating device of the normally open circuit is in the building to
he protected against fire.
But in addition to this double alarm in case of fire the translating device of the
closed circuit normally indicates good onder, for its index is controlled by the smal!
current flowing in the open circuit, of which the loop and rheostat forms a part.
when the apparatus is in order. But should the wire rust out or break, or the
generator fail, or for any reason the current in the clused circuit cease to flow or
become less than normal, then the translating device of the closed circuit indicates
that the apparatus is out of order. And so in case of a cross, or ground of the
closed circuit, or any accident resulting in an increase of current above the normal
in the closed circuit, then also the translating device of the closed circuit indicates
that the apparatus is out of order.
The result is that the attendant at the central or main office is kept constantly
informed as to the condition of the apparatus; and a double fire alarm is sure to be
automatically given in ense of fire in the building to be protected, one alarm in the
central or main office, and another in some part of the building to be protected.
While the thermostat which forms the first feature of my invention, provided
with three electrodes, and a coiled spring held under tension, and out of contact
with two of the three electrodes, is preferable with the apparatus which forms the
second feature of my invention, it will be obvious that two ordinary thermostats
each having but two electrodes may be used, by electrically connecting two of the
four electrodes of the pair of thermostats and thereby making, in substance, a
thermostat with three electrodes.
Dated this 23rd day of Juna 1894
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in Automatic Fire Alarms.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to he particularly described and ascertained in and by the following
statement :-
The purpose of the invention is first to make it more certain that a circuit
closer when operated after long disuse shall effectually close the circuit, and
secondly to make it certain that electrical apparatus, intended to give an automatic
alarm when a given temperature is reached in the neighbourhood of a thermostat ;
shall always be in working order.
The first feature of the invention is an automatic circuit closer composed of the

page_text: ollowing parts; a spring coiled about its inner support, and connected to one
electrode of the circuit; suitable means to hold one of its ends when the spring is
under tension; and an electrode connected to the other pole of the circuit, and out
of contact with the spring when under tension, but so placed as to limit the sidewise
notion of the spring, and permit its endwise motion, when the spring is released;
the main feature being that the spring when released moves sidewise until it comes
nto contact with the electrode, and then moves end wise scraping and rubbing over
the electrode; thereby not only ensuring contact between the spring and the
electrode, but also ensuring such a scraping or rubbing of the surface of the spring
over the surface of the electrode as to make sure of an effectual electric contact
between the two.
In general the spring will be held under tension by soldering its end to some
part of the case of the instrument with solder whose melting point is such that it
will melt and release the spring when the temperature about the instrument is high
enough; but obviously this the first feature of the invention is not limited to
that kind of circuit closers, called thermostats, set in operation by a rise of
temperature.
Another advantage of this feature of my invention is that the spring will operate
successfully with two electrodes, so that the circuit closer may be used to close two
circuits, and make it, preferably with three electrodes, from two of which the
spring is kept out of contact when under tension.
The second feature of my invention is an automatic fire alarm system comprising
the following features; viz., a closed circuit and its translating device or devices;
an open circuit and its translating device or devices; a thermostat with three
electrodes; and a loop circuit containing a rheostat and connecting two of the
three electrodes of the thermostat; the third electrode of the thermostat forming
a part of the open circuit.
The use of thermostats in systems for guarding property against fire by giving
an alarm automatically as soon as any thermostat is exposed to a predetermined
temperature has long been known; but owing to the fact that the apparatus is
likely to remain unused for long periods of time and to the further fact that it is
likely to get out of order before the occasion arises for its operation, its use has
been much restricted. The object of this feature of the present invention is to
provide a system of this kind which will give notice automatically when it is out of
order, whether from accident or design and generally to make the use of thermostats
as automatic fire alarms so certain and efficient that full confidence can be reposed
in such a system in spite of the fact that no occasion for its operation as a fire
alarm may arise for years after it is constructed.
When the temperature rises sufficiently at any one of the thermostats the solder
holding the spring melts and the spring uncoils thereby electrically connecting all
three of the electrodes; and the result is that the loop and rheostat of the closed
circuit is cut out, and the open circuit is closed, and this gives two alarms one
alarm being given by the translating device of the closed circuit, the other by the
translating device of the normally open circuit; and in practice the translating
device of each closed circuit is under the charge of an attendant, at for example a
central or main office, while the translating device of the normally open circuit is
in the building to be protected against fire.
But in addition to this double alarm in case of fire the translating device of the
closed circuit normally indicates good order, for its index is controlled by the small
current flowing in the open circuit, of which the loop and rheostat form a part
when the appäratus is in order. But should the wire rust out or break, or the
generator fail, or for any reason the current in the closed circuit cease to flow or
become less than norinal, then the translating device of the closed circuit indicates
that the apparatus is out of order. And so in case of a cross, or ground of the
closed circuit, or any accident resulting in an increase of current above the normal
in the closed circuit, then also the translating device of the closed circuit indicates
that the apparatus is out of order.

page_text: The result is that the attendant at the central or main office is kept constantly
informed as to the condition of the apparatus; and a double fire alarm is
sure to be automatically given in case of fire in the building to be protected, one
alarm in the central or main office, and another in some part of the building to be
protected.
While the thermostat which forms the first feature of my invention, provided
with threo electrodes, and a coiled spring held under tension, and out of contact
with two of the three electrodes, is preferable with the apparatus which forms the
second feature of my invention, it will be obvious that two ordinary thermostats
ench having but two electrodes may be used, by electrically connecting two of the
four electrodes of the pair of thermostats and thereby making, in substance, a
thermostat with three electrodes.
In the accompanying drawing,
Figure 1 represents a front view of the circuit closer, with a portion of the cover
removed and the circuit closer ready for netion;
Figure 2 represents a front view of the circuit closer with the cover entirely
removed, and the circuit closed by action of the apparatus:
Figure 3 is a transverse section taken substantially on line . . of Figure 1;
Figure represents a circuit closer having three electrodes:
Figure 5 is a diagram of the whole system.
The spiral spring D is secured about the post d so that when the movable end D
is drawn out, and the spring consequently contracted, as in Figure 1, the spring is
out of contact with the electrode a which is insulated at and g; when however
the end D is relieved the spring expands and rubs against the electrode a, as shown
in Figure 2, and closes a circuit between the ground or a line attached to the frame
of the apparatus or connected with electrode a' and a line attached to the insulated
electrode a, by binding post H. The movable end D1 of the spring D is held by
a drop of solder fusible at a certain temperature or by a fusible metal plug as at
in Figure 1.
In Figure 3, the insulation of the electrode a and its binding post H is clearly
shown; and electrode a is brought into electrical connection with electrode a
through the frame of the instrument and the spring D.
In Figure 4, the two electrodes a and a are both insulated from the frame, and
the spring D when released electrically connects both electrodes a and a' with
electrode a, or with the frame of the instrument, when that frame is connected,
as may often occur in practice, with water pipes, or is otherwise electrically
grounded.
In Figure 5, the fire alarm system is shown with the thermostat having three
electrodes a a² a². As an example these thermostats will be arranged on the floors
of a building and all the thermostats on the several floors may constitute one series
so far as concerns the closed circuit, its translating device B and its rheostat R:
but those on one floor will constitute a series so far as concerns the open circuit
and its annunciator or other translating device B'. The closed circuit is from
generator G grounded at E through wire &, galvanometer B, wire 62 through
loop and rheostat R to electrode of the thermostat and thence as by wire to
ground E; and the open circuit is from generator G grounded at E through
wire, annunciator B wire to the electrode a of thermostats connected by
wire ; and when the open circuit is closed by electrical connection of wires i
or with wire 6, through electrode: a and (or otherwise when testing the
apparatus) the open circuit is completed through wire to ground E', thus
operating annunciator B. Normally the current through the closed circuit will
be sufficient to keep the index of the galvanometer B at a position (shown in full
lines) between two other positions (shown in dotted lines), one of which on the left
of the drawing indicates that the apparatus is out of order that is that the
generator has failed or the like; and the other on the right of the drawing
indicates that the thermostats have operated or that there is an excess of current
above the normal as if wire be accidentally grounded. In case the temperature

page_text: at any thermostat becomes excessive the electrodes a a' a² are electrically connected
and an excess current is established through galvanometer B, and a current is also
established through annunciator B'; thus giving a double alarm, one on the floor
where the thermostat is situated and the other at the central office.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondents, I declare that what I claim is :---
First. In an automatic circuit closer the combination of a spring constituting
one electrode and inner and outer supports for that spring when under tension;
with a second electrode out of contact with the spring when under tension but
limiting the sidewise motion and permitting the end wise motion of the spring when
released; all substantially as described.
Second. In combination a case; a coiled spring; its inner support within. and
near the middle of the case; its outer support outside the case; and an electrode
insulated from and within the case; all substantially as described.
Third. A fire alarm system comprising a closed cirenit containing a resistance
and translating device, an open circuit containing a translating device, a thermostat
having three electrodes, a shunt around the resistance closed by two of the
thermostatic electrodes and the open circuit arranged for closure by the third
thermostatic electrode.
Dated his 21st day of Ha 1905
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.