Improved Fire Alarm Apparatus.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improved Fire Alarm Apparatus.
1 ERNST WALDEMAR JUNGNER, Bachelor of Arts, of Skara in the Kingdom
f Sweden do hereby declare the nature of this invention and in what manner the
ame is to be performed to be particularly described and ascertained in and by
he following statement :-
This invention has for its object an electrical fire alarm apparatus so constructed
hat it will automatically make devices for alarming (bells or the like) give a
ignal, when fire arises in the room, stall, manufactory or other place, where the
apparatus or part thereof is placed.
The apparatus is founded on the employment of thermo-electric currents being
called forth by the change of temperature arising by fire in a circuit especially
constructed for the purpose, said thermo-electric currents by special devices being
brought to close a circuit of a battery, into which, means for signalling
are put.
In the accompanying drawing the Fig. 1 is a side view and Fig. 2 a plan view of
the apparatus.
The thermo-electric circuit or apparatus attached to the ceiling or other suitable
place in the room or rooms to be protected against fire, comprises a chain made of
pieces of two different metals for instance copper and iron brazed together
alternately.
The metal pieces may consist in wire or ribbons or have any suitable shape.
Every second soldered joint is surrounded by a heat insulator of cotton, rubber or
other suitable material. If this chain be exposed to a rather sudden and not too
small change of temperature, its ends being in conducting connection with each
other, a thermo-electric current will arise in it taking the one or the other direction,
said current continuing until the change of temperature is conducted through the
heat insulators so that all the soldered joints have again got the same temperature.
The length and size of the metal pieces making parts of this thermo-electric chain
or battery may be varied within very large limits, if it be not intended to, with the
least number of joints, get the best result possible. If the length of every pair of
wires or element is too great the resistance for the same number of elements will
be augmented and the effect less. If they are too short, the heat will be too
suddenly conducted from the free joints to the coated ones.
As iron is a worse conductor than copper as well for heat as electricity, the
pieces of iron wire should preferably be a little shorter and thicker than the pieces
of copper wire.
The heat insulating coating should also be 'of suitable size, shape and length. If
the layer is too thick the chain will be influenced also by slow changes of tem-
perature, if it is too thin the thermo-current will be too feeble and brief. The
coating may preferably extend beyond the joints for a distance and have the shape
of a spool being thickest right around the very joints and getting thinner by
degrees towards the ends.
are not
The thermo-electric chains or battery constructed in this manner
influenced by radiant heat this being to the most parts reflected by the metallic
surface, but absorb heat only by conducting from the surrounding medium. As
they are at the same time not sensitive for slow changes of temperature and are
placed along the borders of the ceiling, an electric current can be excited in them
by no other reason than by a sudden current of heated air, arising just on the
breaking out of a fire.
The current thus excited in the chain by the breaking out of a fire is very feeble

page_text: •
and not able to produce a signal itself. It is therefore brought to influence a very
sensitive apparatus in which it may produce a movement and in this manner close
the current to an ordinary electric battery circuit.
The circuit closer provided by me is shown in the drawing where Fig. 1 is a side
view and Fig. 2 a plan view.
To a bottom plate a adjustable in horizontal position by means of four set
screws a¹ a² a³ a¹ are attached four induction coils bb123 of copper wire spun
with white silk and wound on glass pipes. On the ends of a wooden balance c
attached to a silver wire d are fixed two cylindrical straight magnets e e¹ at right
angles with the balance. Those magnets enter with their ends into the glass pipes
of the coils which have such a position, that the magnets, the balance being in its
normal position, reach to the centre of the coils. The balance is attached so that
the magnets may be freely floating in the pipes. The coils are in conducting
connection one with the other and with binding screws f f¹ which receive the
thermo-current.
The magnets turn different poles in the same direction and the coils are wound
in such manner that a turning of the balance will take place in the one or other
direction, when a current is excited in the coils.
To the one side of the balance is, by means of brass screws g g', secured a plate
or wire of platinum, which by a wire is in conducting connection with the
suspension wired, which in its turn by means of a wire i is attached to a binding
screw k. The plate of platinum forms the one contact piece for the battery circuit.
The other contact piece consists in a second plate of platinum m brazed to an
elastic brass plate m¹ which is fixed to the bottom plate a in conducting connection
with the other binding screw ¹. By means of a screw n the brass plate m' may he
adjusted horizontally and at right angles with the longitudinal direction of the
balance so that the mutual distance of the two contacts will be of suitable extent.
The binding screws are in connection with elements, signal bells, and
interruptor.
If the apparatus is exactly adjusted so that the contact pieces 1 m are in a
suitable distance one from the other, the balance being in its normal position and
the suspension wire without torsion and the ends of the balance right between the
respective pairs of coils and the magnets floating freely in the glass pipes, the
balance will turn so as to close the contact 1 m and make the signal bells ring as
soon as an electric current of sufficient strength is excited in the thermo-circuit.
The balance must of course be suspended in such manner, that it turns even by
very feeble electric currents. To provide the sensibility necessary thereto and to
facilitate an exact adjustment, the suspension devices shown in the drawing may be
employed. The wire d that supports the balance c is at its upper end wound round
a screw or a wooden roll t that is journalled in two supports salient from the head
of a vertical hollow tap or screw through an opening of which the wire passes
and may be attached by means of a brass set screw n.
The hollow tap r may, by a set screws, be fixed in different positions in the
central opening on a horizontal disc p. Said disc has an arm or handle that enters
into a horizontal opening of a support o extending from the bottom plate a and
may be turned and pushed in or out in the opening where it may also be fastened
by means of a set screw . By this arrangement the balance may be adjusted in
three directions forming right angles one with the other.
The lower end of the silver wire is brazed to a brass screw or tap ' fastened
to the centre of a horizontal wooden disc v and in conducting connection with
the contact piece on the balance by a copper wire h. On the periphery of said
disc are uniformly arranged four wooden screws a² 3 each adjustable by
means of one of the brass screws 2 2¹2² 23. The balance c forms at its centre a
disc, at the periphery of which are uniformly attached four silk threads y the
other ends of which are wound each round one of the wooden screws or
taps
just mentioned. By means of said screws or taps the balance may
be exactly adjusted in a horizontal position.

page_text: The lower fastening points of the threads y are preferably arranged in such
manner that two of them are placed in the longitudinal direction of the balance
and the other two on a diameter at right angles with said direction.
In order to facilitate the adjusting of the bottom plate in a horizontal position
by means of the set screws a¹ a³ as a, this plate may be provided with a straight
glass pipe fixed to it at right angles in which is centrally suspended a leaden
ball., The apparatus is then adjusted so that this ball may depend freely without
contact with the walls of the pipe.
The whole apparatus is confined in a case fixed to the wall and having a
vertical door that may be closely shut up to hinder the entrance of dust and
draught.
In the same case the elements may also be placed if they do not give off any
gases, that may hurt the metal parts of the apparatus.
When the contact pieces 1 m are in contact with each other it often happens
that the torsion of the silver wire has not power enough to tear them from
each other, as soon as the thermo-current has ceased. The contact surfaces do
namely exercise a mutual attraction on each other. To avoid this inconvenience
a bell is always attached to the case enclosing the apparatus, the vibrations of
which bell will cause the severing of the contact pieces. If the balance by
influence from without of some kind should be put in motion, a continuous
signal is not to be feared, but only one or more short ones.
The signals given in case of fire will thus also be interrupted. In order that
every signal should not be of too short a durance, the fixed contact piece m is made.
prolonged and flexible so as by its elasticity to yield. to the pushes of the balance.
By this the contact pieces will be in contact with each other for a time at every
closing of the circuit.
By suitable adjustment of the contact pieces m by the screw in the apparatus
is secured against giving signals for any other change of temperature as are
caused by fire. This arrangement will however often be insufficient for the
purpose aimed at.
For such events devices for inserting a greater or less
resistance in the thermo-circuit may be applied close to the case. Those.
devices may consist of a series of rolls 7. 8. 9 10 wound with argentine wire
being in conducting connection with binding screws 1. 2. 3. 4. 5 in which a brass
bar 6 may be inserted, and fixed in such manner that a greater or less. number of
screws may be in conducting connection one with the other, and thus a greater or
less resistance put into the circuit. Before the thermo-current enters the apparatus
it runs through the resistance circuit just mentioned, by which the sensibility is
adjusted. It may however happen that the lighting up and warming up within
the limits of the action of the apparatus is so intense that the apparatus if made.
insensible to them would hardly fulfil its duty. Those circumstances will be at
hand in case of strong heating of the fire places and also of fixed lighting, especially
if the latter be placed near to the walls, where its effect upon the thermo-chain is
the greatest. To annul the effect of warm air currents, called forth by the causes
now mentioned a horizontal wooden plate may be attached in some distance from
the ceiling right above the place from which the warm air mounts, said plate
having on its lower side a thermo chain like that around the ceiling but coiled..
This chain is by means of ordinary conducting wires put into the aforementioned
chain but in such a manner that the respective currents arising in both chains bý
heated air, obtain different directions..
:
If the number of soldered joints on the wooden plate and the distance of the
plate are arranged in the manner that the two currents get alike strength, the
effect of the warm air on the apparatus is conquered. In such apparatus as afore-
mentioned one of the chief conditions for the fulfilling of its duty is that it must
give signals in case of fire wherever it arises within the limits of the territory
intended to be protected by the apparatus.
This condition is also answered by my apparatus as the warm air current,
mounting from a fire within a room always works its way to the ceiling, where it

page_text: extends and soon reaches the cornices. A fire does not however produce an equal
effect on the wires from every part of the room. The nearer to the ceiling and
These
walls the fire is situated, the greater is the effect upon the thermo-chain.
circumstances must be taken into consideration at the adjusting of the apparatus in
rooms where the lighting is movable.
To the end that the apparatus may be enabled to provide a notification of the
occurrence of a fire at any place throughout the building to be thus protected, the
before described chains must be erected throughout the whole building where it is
to be employed, so that every room and every part in it is within the territory of
the thermo-chain.
As also at an alarm of fire it is of importance to know exactly within what area
the fire is to be found, the simplest mode of indicating the location of the fire is to
divide the thermo-chain into several circuits, or use in effect several thermo chains
each in circuit with a relay in the circuit of an indicator at the place where the
alarm is to be given. This system as applied to a dwelling house is shown in Fig. 3
where the respective thermo chain relays A', A2, A3 of the first, second, and third
floors are each in circuit with the battery B, the signal bell C and the respective
indicator 1, 2, & 3 which latter being of any usual construction needs no further
description.
It is of course not absolutely necessary to employ the metals or materials
mentioned in the above Specification; those are rather to be regarded as samples
amongst several possibilities, but the materials quoted may in most cases be the
ones nearest at hand and best corresponding to their different purposes.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I
claim is―
1. Electrical fire alarm apparatus for apartments, stalls, manufactories etc. com-
prising a thermo-electric chain attached to the cornices of the ceiling or other
suitable place within the territory that is to he protected, an electric bell circuit or
other suitable electric signal device attached to a suitable place within or without
said territory, and an electric contact apparatus put into conducting connection
with the thermo-electric. chain, the whole arranged in such manner that the thermo-
electric currents arising in the thermo-chain by the changes of temperature will
influence the contact apparatus whereby the bell circuit will be closed and signal
given.
2. In the fire alarm apparatus mentioned in Claim 1, a thermo-chain consisting
in wires or bands or otherwise shaped pieces of two different metals, for instance
copper and iron alternately arranged and every second soldered joint being covered.
with a heat insulator from for instance cotton.
3. In the fire alarm apparatus mentioned in Claim 1 a contact device comprising
two pairs of pipes of glass or other suitable material wound with insulated metal
wire, that enters into the thermo-electric circuit; a balance:(c) mounted between
the wound pipes or pairs of coils (b 61 62 63³) and easily movable, said balance
carrying a contact piece (1) put into the bell circuit; two straight magnets (e, el)
attached to the ends of the balance, the ends of said magnets floating freely in the
pipes or coils wound with insulated wire and a fixed contact piece (m) also put into
the bell circuit, this piece being attached so that the swaying of the balance under
the influence of the thermo current running through the coil is met by the contact
piece (1) on the balance, whereby the bell circuit will be closed and signal given.
4. A device for bringing the balance mentioned in Claim 3 back to its normal
position, as soon as the thermo-current has ceased, consisting in a metal wire (for
instance silver wire) the one end of which is attached to a fixed support and the
other to the balance or a piece connected with the balance and partaking in its
motion in order that a torsion of said wire may take place at the swaying of the
balance, the wire thus striving to bring the balance back to its normal position.
. 5. A device for prolonging the signal arising by the closing of the contact
5
Į

page_text: pieces (m) mentioned in Claim 3, consisting therein that one of the contact pieces
is made elastic so as to yield when struck by the other and at the return of the
balance accompany the latter for a time.
6. A device for separating the contact pieces (1 m) mentioned in Claim 3 as soon
as the thermo-current has ceased, consisting therein that one or several of the
signal bells appertaining to the bell circuit are placed in or on the case containing
the contact apparatus before mentioned for the purpose, by means of the vibrations
of the bell to facilitate the separating of the contact pieces.
7. A device for adjusting the sensibility of the contact apparatus mentioned in
Claims 1 and 2 consisting therein :-
(a.) That one of the contact pieces (l. m) mentioned in Claim 3 is adjustable in
order to regulate the distance between said pieces.
(b.) That a resistance apparatus is connected to the thermo-chain in order to
enable the putting in of a resistance of variable strength.
8. A special construction of the resistance apparatus mentioned in Claim 76
comprising a series of coils (7-10) of metal wire put into the thermo-circuit and
a series of binding screws (1-5) in conducting connection with said coils (7-10)
and the two utmost ones of said screws (1, 5) directly with the thermo chain and
also a metal bar (6) adapted to be inserted into an opening in the binding
screws (1-5) and fastened there in several positions in order, by adjusting of the
bar (6) to put a greater or less number of screws in derivation and by this make
the resistance of the thermo circuit less or greater.
9. A device for annulling the effect on the thermo-chain of fixed light and heat
sources consisting in a second thermo-chain like the one attached to the ceiling and
placed right above the latter chain, this second chain being put into the principal
thermo-chain by means of ordinary conducting wires, but in such manner that the
current of the different chains get opposite directions.
Dated this 31st day of October 1893.
R. HADDAN,
Of the Firm of Herbert Haddan & Co.,
18, Buckingham Street, Strand, London, W.C.
R. HADDAN,
Of the Firm of Herbert Haddan & Co.,
18, Buckingham Street, Strand, London, W.C.