Improved Apparatus for Giving an Alarm in Case of Fire or other Emergency and for Signalling or Transmitting Instructions or Information relative thereto.
Year: 1887

page_text: Improved Apparatus for Giving an Alarm in Case of Fire or other
Emergency and for Signalling or Transmitting Instructions or
Information relative thereto.
I, GEORGE FREDERICK REDFERN, of the firm of G. F. Redfern & Co., the General
Patent Office, No. 4, South Street, Finsbury, in the County of Middlesex, Patent
Agent, do hereby declare the nature of this invention (a communication from
abroad by Louis Digeon, of Paris, in the Republic of France) to be as follows:-
This invention relates to a system or arrangement of apparatus termed the
"Universal Alarm" which has been designed for the purpose of giving an alarm in
case of fire or other emergency and for signalling or transinitting instructions relative
thereto.
The improved system or arrangement of apparatus is based on the employment of
a continuous current, of alarm apparatuses connected in the same circuit and of
telephones (or microphones with a telephone). It comprises principal stations and
secondary or intermediate stations. The battery which operates the whole of a system
is placed in one of the principal stations that is to say in one of those which furnishes
assistance or information. All the principal stations are further provided with bells
actuated by means of a local battery, a special relay and a magnetic telephone (or
microphone with telephone) suspended from the hook of one of the arms of a special
automatic commutator.
"
Each principal station can be "called " from and can communicate with all the other
principal stations. The secondary or intermediate stations are stations from which
"calls"
can be made only. They are only provided with a telephone and special
automatic commutator. The secondary stations can be located either in a room or in
a public thoroughfare; in the latter case the commutator and the telephone are
enclosed in a box the front of which glazed on the glass being broken a locking
bolt is disengaged and the telephone can be taken from the box and applied to the ear.
This operation gives a rocking movement to the special automatic commutator and
consequently causes the telephone to be placed in circuit after a momentary rupture of

page_text: the line in each of the principal stations causing the armature of the relay held in
contact with the electro-magnet by the continuous current to leave it under the action
of a spring and close the circuit of the local battery. The officials at the principal
stations have then only to take their telephone from its hook and enter into
communication.
It will thus be seen that when it is required communicate with a principal station
from a secondary station in a public thoroughfare it is only necessary to break the glass
of the box which allows of the box being opened when the telephone can be taken out :
communication can also be obtained with all the principal stations from a secondary
station in a room. To facilitate communication the official in the principal station
provided with the battery replies only to the person calling, only communicating with
stations of the same denomination when it is necessary so to do.
The alarm apparatuses of the principal stations are provided with means for breaking
the circuit of the local bell during the time conversation is being carried on: further
the special automatic commutator of the battery station is so arranged that during the
same time no current circulates over the line.
Dated this 11th day of November 1887.

page_text: COMPLETE SPECIFICATION.
Improved Apparatus for Giving an Alarm in Case of Fire or other
Emergency and for Signalling or Transmitting Instructions or
Information relative thereto.
I GEORGE FREDERICK REDFERN, of the firm of G. F. Redfern & Co., the General
Patent Office, No. 4, South Street, Finsbury, in the county of Middlesex, Patent
Agents, do hereby declare the nature of this invention (a communication from abroad
by Louis Digeon of Paris, in the republic of France) and in what manner the same is
to be performed to be particularly described and ascertained in and by the following
statement:-
This invention relates to a system or arrangement of universal alarm apparatus
which has been designed for the purpose of giving an alarm in case of fire or other
emergency and for signalling or transmitting instructions or information relative
thereto, that is to say, there being one or more stations which can furnish assistance
and an indefinite number of "call" stations all situated on a single line wire and
distributed over an area of several kilometers, a person can, from any one of the "call"
stations, call up the assistance station or stations, acquaint them with the exact object
and locality of the call, transmit to the station or successively to each of the stations
all necessary communications, and receive from the station or stations called up any
information which may be useful.
These numerous results are obtained by means of an arrangement which comprises an
alarm apparatus, a special automatic commutator and a number of telephones or
(according to the distance) of telephones and microphones connected in the same
circuit normally traversed by a continuous current.
In order to enable the invention to be fully understood I will describe. how it
can be carried into practice by reference to the accompanying drawing.
I will commence by describing the alarm apparatus illustrated in Figures 1, 2, 3,
and 4.
The apparatus comprises an electro magnet H, the armature F of which is fixed by
its middle part to a horizontal rod N which passes through the plate L. The armature
is adapted to be slid when required, on the pins m and m¹ carrying the cores of the
magnets. Underneath the armature are soldered two small vertical pins i and i¹
which are caused to rub upon the plates D and D' only when the horizontal rod N is
relieved from the action of the spring G which surrounds it. An endless screw V
which bears against a screw B of the plate L limits the movement.
In this position a handle or switch having knobs serves to break the circuit
of a bell, the circuit being formed by the terminals P and S between which the
switch is placed, the stud J, the plates D and D¹, the vertical pins i and i¹ and the
armature F.
The terminals A and T. C. receive the ends of the coils of wire. The knob E, at

page_text: the end of the rod N and which is situated outside the box covering all the other
parts, serves to bring back the armature F into contact with the cores and the
switch K in the normal position.
The automatic commutator is illustrated in Figures 5 and 6 and is constructed of a
lever a, b, c pivotted on an axis b. The two arms of this lever are unequal in order
to obtain a rocking action. The shorter arm a, b carries a hook f on which a telephone
is hung. Four plates e, g, h, i are placed parallelwise in pairs at the sides of the
other arm and the plates e and h each carry a strip of flexible copper m and n.
According to the direction of movement given to the lever, communication is
established between the two upper plates, the two lower ones being then disconnected
or vice versa.
The assistance stations with a line battery, as shown in Figure 7, comprise an
alarm apparatus, a special automatic commutator, a telephone (or telephone and
microphone) a bell and the line battery which operates the whole system.
The alarm apparatus is fixed vertically with the armature below. The same remark
applies to the commutator of this station the communications of which are thus
established; terminal p-plate g, terminal s-plate e, terminal t-plate h, terminal d-plate i.
To the plate p is connected the positive pole of the line battery; to the terminal d is
attached a shunt wire connected to the negative pole and leading to earth or to a
corresponding station. The terminals s of the commutator and a of the apparatus are
connected together. One of the wires of the telephone apparatus is attached to the
terminal t and the other to the terminal t, c of the apparatus whence proceeds the exit
wire. The line battery can actuate the bell but it is preferable in view of possible
derangement to actuate by one or two Leclanché batteries, which serve to permanently
control the condition of the line battery.
The circuit of the bell is formed as follows:--positive pole, terminal p of the
apparatus, handle or switch k, stud j, plate d, armature f, plate d', terminal s, bell and
negative pole.
The assistance stations without a line battery, if there are several, are illustrated in
Figure 8 and comprise the same elements with the exception of the line battery. The
arrangement is almost identical except that it has no shunt wire and that the
commutator has only three terminals.
The call stations comprise a commutator and a telephone. The commutator is fixed
vertically and its connections are as follows:-terminal s-plate e, terminal l-axis b of
the commutator, terminal t-plate h. The terminals and s receive the exit and
entrance wires of the station. The telephone wires are connected one to the
terminal and the other to the terminal s.
The number of these stations to be connected in a circuit is indefinite. They can
be established in houses of persons connected with the police stations or fire stations
or in private or public buildings.
The working of the system shewn in Figure 7 is as follows:-
At the assistance station provided with the line battery the telephone is suspended
from the book of the commutator and the same is done in the other stations; the
arms of the commutators rock, the plates g and e are connected whilst the two lower
ones are disconnected and the current flows through the following route; the electrode
of the positive pole, the terminal p of the commutator, the plate g, the strip m, the
plate e, the terminals, the terminal a of the alarm apparatus, the coils, the
terminal t, e, the line wire, the entrance wire of the call station; (Figure 9), the terminall,
the axis band the arm b, c of the lever, the plate g, the strip m, the plate e, the terminals,
the line wire, the entrance wire of the assistance station (Figure 8) not provided with
a battery; the terminal t, c of the alarm apparatus, the coils, the terminal a, the
terminals of the commutator, the plate e, the strip m, the plate g, the terminal p,
the line wire, and so on for each of the other stations which may be provided.
By the passage of the current in the coils of the alarm apparatuses, the cores are
magnetised. If by means of the knob E of the rod N, the armature F be brought
into contact with the cores, this armature will adhere thereto so long as the
magnetisation continues.

page_text: In this position, the plates h and i of the commutators being isolated, the telephonic
apparatuses are placed outside the circuit.
By an interruption of the current, the cores of the alarm apparatuses lose their
magnetic properties, the armature is moved by the spring G and the small pins
thereon slide over the plates d and d' and close the circuit of the bell. Under these
conditions the call of the latter will be heard and the assistance stations are called up.
Now if at the call station (Figure 9) the telephone be unhooked, this interruption of
the current is produced during the time that the strip of the commutator-lever leaves
the strip m for the lower strip n (the commutators of the stations, Figures 7 and S,
can be operated in the same manner). Consequently the bells are set in action.
The call having been heard in each of the assistance stations the handle or switch k
must be turned with one hand and the telephone be unhooked with the other hand and
placed to the ear. By this simple action the following results will be obtained.
Istly, the bells will be cut out; 2ndly, the telephonic apparatuses will be placed in a
circuit without shunt; 3rdly, the alarm apparatuses are also cut out; 4thly. the line
battery of the station, Figure 7, will be momentarily disconnected.
In fact, in this position the plates and i of the commutators are in communication
whilst the upper plates are not in communication. There remains only a telephonic
circuit free of all useless resistances.
Any phonic messages sent from the call station, figure 9, can now be distinctly and
simultaneously received at the assistance stations, figures 7 and 8, and from the call
station any required conversation can be carried on with the two others, figures 7
and 8.
:
In order to avoid confusion during the conversation the following rule should, be
observed the station spoken with must reply and if it is required to interrupt the
course of a conversation to transmit an urgent order it is only necessary to blow a
trumpet attached to each telephone the sound of which trumpet will be transmitted
to 1 50 from all the instruments which are in connection to cut out the speakers and
call up the station with which it is desired to communicate.
The alarm apparatus and the bell which compose each of the principal stations
can be mounted on the same board or table by employing a single electro-magnet and
a single armature (figures 10 and 11).
On a bent copper plate T rests an electro-magnet H. An armature F is carried by
a spring R. One end of this spring rests against the point of a screw-block V and
the other end is fixed on the vertical part of the plate T which serves to firmly hold
the electro-magnet H. The armature F is provided with a rod carrying a hammer
which strikes a bell. A copper plate G is fixed horizontally on the table. The ends
of this plate are bent up at a right angle and they carry a rod N. A knob E is fixed
on one of the ends of the rod N; the other end carries a small arm I. A switch K
is placed between the knob E and the plate G. It serves to break the circuit of
a local battery. A small plate L is so placed that it is isolated when the
armature F is in contact with the cores and is projected onto a flat spring x
when the armature is no longer attracted and the spring R presses against the
screw V.
The rod N allows of bringing back the armature into contact with
the cores, the switch K onto the stud J when it has been moved; and the plate Linto
its isolated position.
The terminal A (figure 10) is connected to the entrance wire of the coils, to the
axis of the switch K and to the plate L; the terminal T C to the plate G; the
terminal P to the screw V; the terminal S to the stud J and the flat spring x to
the plate G.
The operation of the apparatus is as follows:-
To the terminals A and T C are attached the entrance and exit wires of the principal
station. To the terminals P and S are attached the poles of the local battery. It is
known that by hooking the telephone to the hook of the commutator of the battery
station, the current will pass through the line. It is then only necessary
the
press
knob E to bring the armature F into contact with the cores where it will remain so
long as the magnetisation continues, that is to say, until from any cause the current is
to

page_text: interrupted. In this position, the screw R and the plate L being isolated, the current
takes the following course :-positive pole of the battery, commutator, terminal A of
the bell-alarm apparatus, coils, armature F, rod N, terminal T C and negative pole of
the line battery.
By unhooking the telephone of one of the principal or intermediate stations an
interruption of the current is produced. The cores of the electro-magnet becomes
demagnetised the armature F being no longer attracted moves away therefrom and
carries with it the rod N, the plate L on the stud J, and the spring R bears
against the screw V. The circuit of the local battery is closed and the apparatus
only acts like an ordinary electric bell. In re-establishing the current through the
line the knob E is simply pressed to put the station in working condition.
With regard to the alarm, bell, and commutator apparatus, as will be seen by reference
to figure 11, the bell-alarm apparatus may comprise the same parts of which the special
automatic commutator is composed.
The lever a, b, c is cranked. A spring holds or moves the arm b, c onto the stud į
when the telephone is unhooked. A second hook f¹ serving to receive a second
telephone is placed on the other side of the apparatus.
The stud e is connected to the axis of the switch K, to the flat spring and to the
entrance wire of the coils; the stud g to the terminal A which receives the entrance
wire of the station and to the stud ; the stud i to the terminal t; the stud / to the
terminal D which receives the shunt wire; the terminal to the terminal T C from
which starts the exit wire of the station, to the plate G and to the terminal 3; the
terminal t² to the terminal t; the screw V to the terminal P; and the stud J to the
terminal S. To the terminals t¹, t², t³, and are attached the wires of one or two
telephonic apparatuses.
This apparatus can be placed in a station provided or not with a line battery. In
the former case the communication is broken between the studs y and h; in the second
case it is allowed to exist and the terminal D does not receive any wire. By referring
to the figure it will be seen how the circuit is formed according to whether the telephone
is suspended or unhooked.
In the case where a number of principal stations are connected in a single line
(such as when the system is applied in mines, on railways, in fortresses, &c.) an
addition made to the alarm apparatus allows of two or more of these stations to
communicate with each other without those which are not intended to take part in the
conversation being required to listen to replace their station-apparatus in order when
the conversation has ceased. The bell will inform them.
Figure 12 represents an alarm apparatus of this description.
Besides the parts described it comprises 1st. A small electro magnet / which is
placed below the rod N which is bent for this purpose and provided with an arm p;
2nd, a jointed plate e carrying an armature a and a small counterweight b; 3rd, a
flexible strip; 4th, a switch M the moveable end of which can be placed over the
stud C, over the stud d or over both at the same time; 5th, two terminals Y and Z.
By pushing the rod N, the arm p serves to move the armature a and to keep it away
from the cores of the electro-magnet when it has been attracted.
By reference to figure 12 it will be seen that when the switch M is over the stud C,
which it ordinarily is, only the coils of the electro-magnet H are included in the
circuit. When this switch is over the stud d only the coils of the electro magnet h
are included in the circuit. By causing a current to flow through the circuit it will
be seen that in the first case the armature F placed in position by pushing the rod N
remains in contact with the cores of the electro-magnet H whilst the armature a is
kept apart from the electro magnet ; in the second case, the armature a is attracted
the circuit of the local battery is consequently closed. A silver contact piece soldered
on the armature a being in contact with the flat spring r, the bell is set in action and
it continues to act until the armature a is withdrawn by moving the rod N. The
switch M is then replaced over the stud C. In order then to converse it is only
necessary to unhook the telephone; in order to be warned when the other stations
have finished conversing it suffices to place the switch M over the stud d.

page_text: This arrangement is in itself another mode of construction allowing of dispensing
with the employment of a continuous current and its application is claimed in case of
requirement.
Should the trumpet be insufficient to warn the person who gave the alarm to the
intermediate station, an ordinary bell can be interposed in the telephone-circuit at
each of the call stations. This bell is set in action as soon as the telephonic apparatus
is unhooked or introduced into the line and it continues to act until at the line-battery
station the telephone has also been unhooked. By means of a double contact piece
which is normally electrically disconnected and a third terminal connected with the
terminal of the exit wire of the station, this bell can be placed in shunt as soon as it
is put in action. The telephone can be caused to emit a loud sonorous sound and the
trumpet and bell be therefore dispensed with.
Figure 13 represents an alarm apparatus for the line-battery station suitable for
this purpose.
At the sides of the electro magnet H are placed two jointed plates and provided
with springs and which only bear against the screw studs p and p' when the
armature F, the ends of which carry extensions of insulating material, is in contact
with the cores. When the armature F is moved by the spiral spring G, the jointed
plates and come against the studs c and c¹. The jointed plates and can be
replaced by flexible strips.
In the position represented in figure 13, the telephone t2 emits a loud sound owing
to the interruptions of the current produced by the bell which is interposed in the
line-circuit. By unhooking the telephone t¹ the battery (circuit indicated by the dotted
lines) is omitted and the loud sound ceases until the telephone t¹ is again hung up.
By moving back the armature F the springs r and bear against the screw studs P
and while the studs c and c¹ are isolated and consequently the bell is placed outside
this circuit.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
The herein described arrangements for giving an alarm in case of fire or
other emergency and for signalling or transmitting instructions or information
relative thereto.
10:1
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