IMPROVEMENTS IN APPLYING ELECTRICITY, AND APPARATUS CONNECTED THEREWITH.
Year: 1878

page_text: LETTERS PATENT to Edward Brailsford Bright, of 11, Delahay Street, West-
minster, in the County of Middlesex, Civil Engineer, for the Invention of
"IMPROVEMENTS IN APPLYING ELECTRICITY, AND APPARATUS CONNECTED
THEREWITH.
"
Sealed the 6th August 1878, and dated the 13th February 1878.
PROVISIONAL SPECIFICATION left by the said Edward Brailsford Bright at
the Office of the Commissioners of Patents on the 13th February 1878.
EDWARD BRAILSFORD BRIGHT, of 11, Delahay Street, Westminster, in the County
of Middlesex, Civil Engineer. "IMPROVEMENTS IN APPLYING ELECTRICITY, AND
APPARATUS CONNECTED THEREWITH,"
My Invention consists in the employment of artificial electrical measures of
resistance (or rheostats) for the purpose of making known the locality of a fire
or of changes of temperature, such artificial measures of electrical resistance being
used in combination with thermostats or appliances for closing or opening or making
a variation in an electrical circuit or circuits by such fire or change of temperature.
My Invention is also applicable to doors, windows, safes, sluices, valves, &c., the'
opening or closing of which may be required to be made known, in which case the
electrical circuit is closed, opened, or varied by the movement of such door, window,
et cetera.
In order to describe my Invention concisely and to dispense with frequent
repetitious, I use the following words, in the singular or plural, with the signification
attached to them.
Firstly. By the word" rheostat' I mean artificial measures of electrical resistance,"
which may be made of definite lengths of metallic wire arranged in coils, or other-
wise, or of tubes of mercury or distilled water or other fluids, or in any other
convenient manner for affording measures of resistance to the passage of a current
of electricity, but I prefer to use coils of wire.
Secondly. By the word thermostat'. I inean -the apparatus primarily affected'
by the change of temperature of which it is desired that notification should be made..

page_text: This apparatus may be made by adapting any form of pyrometer to the making or
breaking electrical contact, or materials which are fused or softened by heat may
be adapted to the same purpose, but I prefer to use a spring composed of two metals,
which are differently expanded and contracted by changes of temperature, so that
a movement at the end of the spring produced by the change of temperature causes
electrical contact to be made or broken.
Thirdly. By the word 'protector' I mean apparatus not influenced by heat,
which opens or closes an electrical circuit by movement of the door, window, sluice,
valve, or other object to which it is fixed. I prefer to employ a metallic spring
faced or shod with platinum in connexion with an insulated metallic stud or studs
faced with platinum for such purpose.
Fourthly. By the term 'protected place' I mean the locality, premises, or thing
to be protected by electrical signals giving notice of fire, change of temperature,
or attempts at robbery, or the opening of doors, sluices, or valves, either on land
or in vessels afloat.
Fifthly. By the word 'station' I mean any fire brigade or police stations or
other points (such as the captain's cabin in a vessel) to which it is desired to notify
the alarm or warning.
In my Invention I employ rheostats at the stations in combination with thermo-
stats or protectors or both at the protected places.
I also employ rheostats in the protected places, or the rheostats may be placed
at any convenient intermediate point or points between such protected places, but
it is not essential that there should be any special rheostats at the protected places
as the length of the conducting wire from the stations to and in each protected
place may of itself furnish the required measure of electrical resistance corresponding
to that of the rheostats at the stations.
The thermostats or pyrometers at the protected places may also be so constructed
as to afford a definite electrical resistance in conjunction with the conducting wire,
and thus provide a measurement of locality in combination with the station
rheostats.
I also employ apparatus at the stations by which the locality of the fire or point
from which the warning proceeds is made known by means of rheostats in connexion
with an electrical alarum, either separately or together with a galvanometer or a
dial or other indicating apparatus, or a recording or a letter printing or other
telegraph instrument.
་
I also employ in connexion with rheostats an alarum or other apparatus for
giving signals placed in or outside buildings for such purposes as aforesaid.
I also employ opposing electrical currents in combination with rheostats for
such purposes as aforesaid.
I also employ one or several electrical circuits, either metallic or in connexion
with the earth or both combined, such circuit or circuits being used in connexion
with rheostats for such purposes as aforesaid.
The main conducting wire or wires between the station or stations and the pro-
tected places may be constructed in any usual or convenient manner.
I connect in the circuit or circuits, formed by the conducting wire or wires,
a series of rheostats, either in or between the protected places, or I measure tlie
several lengths of such conducting wire between and in each protected place, and
the station or stations, as aforesaid, and employ them as rheostats.
The thermostats or protectors are fixed in the required positions in the protected
places, and are electrically connected on one side to the conducting wire, and on
the other side to a wire connected with the earth or with a second conducting
wire.
One rheostat in connexion with several thermostats or protectors may be used to.
indicate the position of an entire story or building.
For convenience I use in the foregoing manner rheostats of similar electrical
resistance or measured lengths of the conducting wire or wires to indicate each
protected place, but the method may be varied by causing the action of the ther-
.10.

page_text: nostats or protectors to bring into circuit at any protected place a rheostat of
distinctive resistance, differing in its electrical resistance from any other rheostats
at the other protected places. Such rheostat may either form part of a branch
electrical circuit, or by the action of the thermostat or protector be brought into
connexion with the main circuit, or with an auxiliary wire as well as the main
conducting wire.
At the stations I connect galvanic batteries or any other convenient electro-
motors, such as thermo-electrical apparatus or magneto-electrical machines, with the
conducting wire or wires, and with the earth.
I also connect such electro-motors with rheostats at the stations, so that when a
warning is given from any protected place by a thermostat or protector coming into
action and making, breaking, or varying the circuit or circuits, the rheostat at the
station is brought into electrical balance with the rheostat or rheostats in circuit
with the conducting wire or wires. In this manner the point from which the
warning proceeds is accurately defined.
For the purpose of denoting the particular protected place from which the
warning proceeds, I use clock work or other mechanism at the station brought into
operation by the current of electricity, which indicates the particular protected place
when the resistance of the station rheostat on the one hand, and of the electrical.
circuit made by the thermostat or protector at the protected place on the other hand,.
are equal.
By another arrangement for the same purpose, the electrical balance of the station
rheostat with the circuit made by the thermostat or protector is effected by hand
instead of automatically. In this case, I employ an upright shaft or other suitable
mechanical arrangement, which may be actuated by means of a handle, bringing
successively into connexion with the electro-motor the different measured lengths of
the station rheostat.
To call attention instantly upon any thermostat or protector coming into.
operation, I insert in connexion with the conducting wire at the stations or any
suitable point an electrical alarum or alarums, and I also employ an alarum or
alarums, separately connected in combination with a continuous current or an
intermittent current controlled by clockwork mechanism at the station, in order to
indicate any break of the conducting wire.
In connexion with the station rheostats for balancing the electrical current or
currents, I employ either differential galvanometers or electro-maguetic coils, or I
use the mode of connexion technically known as a 'bridge.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Brailsford Bright in the Great Seal Patent Office on the
· 12th August 1878.
.
EDWARD BRAILSFORD BRIGHT, of 11, Delahay Street, Westminster, in the County
of Middlesex, Civil Engineer. "IMPROVEMENTS IN APPLYING ELECTRICITY, AND
APPARATUS CONNECTED THEREWITH."
My Invention consists in the employment of artificial electrical measures of
resistance (or rheostats) for the purpose of making known the locality of a fire or of
changes of temperature; such artificial measures of electrical resistance being used
in.combination with thermostats or appliances for closing or opening or making a
variation in an electrical circuit or circuits by such fire or change of temperature..
My Invention is also applicable to doors, windows, safes, sluices, and valves, the
opening or closing of which may be required to be made known, in which case the
electrical circuit is closed, opened, or varied by the movement of the same.
It may
also be applied in vessels, to give warning to the captain or officers of undue heat
occurring in the holds, coal bunkers or other places.
.
In order that my said Invention may be most fully understood and readily carried
into effect, I will proceed to describe the Drawing hereunto annexed.
DESCRIPTION OF THE DRAWING.
Figure 1 shews a rheostat consisting of a coil of insulated wire (which I prefer
to be made of German silver, being little susceptible of variations of conductivity
arising from changes of temperature). The wire is varied in length according to the
electrical resistance which it is desired to place in circuit, and its ends are connected
with two metallic terminals a and b placed outside the coil. A rheostat is fixed at
any point from which a warning indicating locality is required, and may be fastened
by means of the screw shewn passing through the centre.
Figure 2 is a section, and Figure 3 a side view of a thermostat consisting of a
metallic box inside of which is fixed a curved band c, formed of two metals, such as
platinum and brass, which expand unequally under the influence of heat. Opposite
the end of the band c is an insulated screw d, which can be so adjusted that the
addition of any given amount of heat will by its effect upon the band bring the end
of the band c into contact with the end of the screw terminal d. The terminal e is
connected with the metallic box, and therefore with the curved band c.
Figure 4 is a general plan shewing the apparatus I employ at the fire brigade
station or other place to which a warning is to be given, and also a diagram of the a
electrical circuits in connection with the thermostats and rheostats by which the
locality whence the warning proceeds is indicated.
Figure 5 is a side view of the indicating apparatus at the fire brigade station or
other place to which a warning is to be given, and Figure 6 a top external view of
same.
The series of circles marked with numbers varying from 5 to 15 included by the
bracket f, represents a number of rheostats placed in the various buildings or places
from which an alarm may be given. They are connected together by a line wire g
extending to the fire brigade station, as shewn by the diagram, which wire is there
joined to one side of the differential coil h, and thence through the alarum i to one 4
pole of the battery j. The same pole of the battery j is also connected through the
alarum to the other side of the differential coil h, and thence to the end of a series
of rheostats fixed round a circle in the indicating apparatus at the station, which
are also marked on the plan with numbers varying from 5 to 15, indicating electrical
resistances corresponding with those of the rheostats included in the bracket f before 5
described.
By means of the handle k the arm 7 with a spring m can be moved over a series
of metallic plates n, n, which are insulated from each other, and connected consecu-
tively with the rheostats, as shewn on the plan. The arm and spring m are

page_text: connected with the other pole of the battery j, which is also connected to the earth.
To the handle is attached a pointer o moving outside the dial of the instrument
over a circle of figures corresponding to the number of rheostats in the circuit.
Connected to one end of each of the rheostats included in bracketf is a thermostat,
the insulated screw of which (d, Figures 2 and 3) is connected to the earth. On
any undue increase of heat taking place, the band c (Figures 2 and 3) of the
thermostat makes contact with the insulated screw d (Figures 2 and 3), and thus
completes the circuit with the battery j, as shewn by the dotted line p.
The electric current from the battery j passing thus through the alarum i rings
it, and also passing through one side of the differential coil h, deflects the disc q,
which is fixed to the axle of a permanent magnet contained within the coil h. On
the alarum being thus given, the person summoned moves the handle k round the
dial of the instrument, and as soon as the spring m comes into contact with the
particular plate n connected with the rheostat that corresponds with the line rheostat
which has been put to earth by the thermostat at the point from which the alarm
is given, the electrical balance of the differential coil h is re-established, and the
disc q returns to zero.
The pointer o indicates the number on the dial of the station instrument which
corresponds with the number of the place on the station list from which the
alarm emanates.
In the plan of the apparatus as drawn in Figures 4, 5, and 6, only fifteen pro-
tected places are shewn,.but a larger or smaller number can be connected.
Figure 7 shews by a diagram how one rheostat r may be connected with any
number of thermostats 8, 8, distributed over a building or a storey of a building.
Figure 8 shows how one station instrument may be employed in connection with
a number of wires and sets of protected buildings in various directions. In this
drawing five wires marked A, B, C, D, and E are shewn, each of which is connected
with a separate metallic plate, as shewn by the dotted lines, and also with an
indicating coil and needle shewn by a circle under each letter; the plates may be
connected by metallic plugs to a metallic plate connected with the alarum, and
thence to one pole of the battery, as shewn in the drawing, or to the station indi-
cating apparatus by a similar metallic plate on the other side. So long as there is
no action of a thermostat on any of the circuits, they are all connected by the plugs
to the alarum plate. On an alarm being given the alarum sounds, and the needle
of the indicating coil connected with the wire affected shews which circuit has to
be disconnected from the alarum and put on to the station-indicating instrument.
Thus, if the signal comes along E, and No. 40 is indicated, a reference to the station
list shews from which place the alarm emanates.
Figure 9 shews apparatus by which the locality of each of several fires occurring
about the same time on the same wire inay be separately indicated. In this method,
the rheostats t, t, t, t, at the various places protected have each a distinctive
electrical resistance, corresponding with which is a double set of rheostats in the
station instrument.
One set of rheostats u, u, u, u, in the station instrument is connected in the
station circuit, but is kept on short circuit by plugs inserted in the holes shewn in
the Drawing, the other set of station rheostats v, v, v, v, is so arranged as to be
brought successively into circuit by the movement of the handle w, with its arm
and spring. The line rheostats t, t, t, t, are kept on short circuit by the thermostats
x, c, x, x, which are arranged to open out and bring their respective rheostats into
circuit on the application of heat.
When at rest, no rheostat is in circuit on the line or in the station instrument
except just sufficient electrical resistance in the zero of the station instrument to
balance the electrical resistance of the line wire circuit. A current is continually
flowing from the battery y through the line wire circuit, and one side of the
differential coil z, and also through the station instrument at zero, and the other
side of the differential coil z¹:
On a fire occurring, the thermostat at the place affected is withdrawn from its

page_text: stud, thus bringing the rheostat into the line circuit, and so disturbing the balance
of the coils, z, z¹, and giving the alarm. Upon the handle w being turned, the
rheostats v, v, v, are brought separately and successively into the station instrument
circuit, until the rheostat of the series v, v, v, which corresponds with the rheostat t,
from which the alarm comes has been reached, when the electrical balance being
restored, the indicators of z, z', returns to zero and the locality of the fire is known.
The rheostat in the series u, u, u, u, corresponding with the rheostat t, from which
the alarm is given, is then brought into the station instrument circuit by with-
drawing its plug, and the handle w and spring are brought back to zero.
The line
circuit and station circuit are thus balanced again.
. Upon another fire occurring the same process is repeated, another rheostat u
being brought into circuit corresponding with the rheostat t at the point of fire,
thus again balancing the line circuit. This may also be effected without a second
set of rheostats in the station instrument, by leaving the indicating rheostat in
circuit by means of a double plug connection.
Figures 10 and 11 shew a train of clockwork brought into action by a differential
relay, which moves round the contact maker in connection with the station rheostats
in case of fire, until the balance between the station rheostats and the line rheostats
is re-established, when the indicating hand attached to the axle of the contact
maker (as in the apparatus worked by hand shewn at Figure 4) points to the
number shewing the locality of the fire. In this figure a, a', are the differential
coils of the relay; b is the contact maker influenced by them; c is the battery of
the line and station circuit, and d the battery of the local relay circuit; e is the
coil of the alarum, and f is an electro-magnet actuating an armature g, and thus
releasing the escapement or detent h¹.
For giving indications of the opening or closing of doors, windows, safes, sluices,
or valves, by my improvements, I arrange that such opening or closing shall act
similarly to the thermostat spring herein-before described, in making or breaking
contact, and so shewing the locality by means of a similar arrangement of rheostats
to that described for the fire brigade apparatus.
Having thus described my said Invention and the best means I am acquainted
with for carrying the same into effect, I wish it to be understood that what I
claim is,―
Firstly. The making known the locality of a fire or of changes of temperature
by the employment of artificial measures of electrical resistance (or rheostats) in
combination with thermostats or appliances for closing or opening or making a
variation in an electrical circuit or circuits by such fire or change of temperature."
Secondly. Indicating by means of artificial measures of electrical resistance (or
rheostats) the opening or closing of doors, windows, safes, sluices or valves.
Thirdly. The general arrangement and construction of apparatus or mechanism
for indicating the locality of a fire, or change of temperature, as herein-before
described, and represented in the accompanying Drawing,
In witness whereof, I, the said Edward Brailsford Bright, have hereto set my
hand and seal this Tenth day of August, in the year of our Lord One
thousand eight hundred and seventy-eight.
Witness,
G. F. REDFERN,
Patent Agent,
4, South Street,
Finsbury,
London.
E. B. BRIGHT. (L.S.)