Improvements in Electric Signalling Apparatus.
Year: 1894

page_text: Date of Application, 17th July, 1894-Accepted, 13th Oct., 1894
COMPLETE SPECIFICATION.
[Communicated from abroad by THE STANDARD ELECTRIC SIGNAL COMPANY,
of Rochester, New York, United States of America.]
Improvements in Electric Signalling Apparatus.
I, CHARLES ARTHUR ALLISON, of 52 Chancery Lane, London, in the County
of Middlesex, Patent Agent, 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 :-
This improvement relates to electric signalling apparatus, and consists in the
combination and arrangement of parts hereinafter described,-
In the drawings-
Fig. 1 is a plan showing the general system;
Fig. 2 is an enlarged face view of the differentiating apparatus with a portion of
its top broken away;
Fig. 3 is a plan of the relay;
Fig. 4 is a perspective view of the electrical stop;
Fig. 5 is a plan of one of the street boxes with a portion of its top removed;
Fig. 6 is a similar view of one of the sub-station or auxiliary boxes;
Fig. 7 is a cross section of one edge of the box shown in Fig. 5:
Fig. 8 is a horizontal section of the stop arrangement of the box shown in
Fig. 6;
In this system a central station or office is used in which are located the
working parts.
A indicates the relay, B the differentiating apparatus, C an engine house or fire
department station, E a police or other station, and F an electro magnet for
operating a register at the central station, whereon is recorded the number of the
box from which the signal is sent. The relay A consists of two pairs of electro
magnets a, a, and a', a', two sets of uprights e, e, and e¹, e', two sets of swinging
arinatures c, c¹, c³, and c³, c, c³, located at opposite ends of the magnets, and two
upright contact posts band. The armatures play between the magnets and the posts.
The differentiating apparatus B, consists of a box provided with a conducting
base plate fand an exterior face d, of insulating material. g is a time movement or
clock work, and h an escapement connected therewith. i is an arm, forming a
circuit breaker attached to a shaft of the time movement extending out through the
insulated face, the arm resting across the face, but not in contact therewith. The
time movement gives motion to the arm and causes it to traverse over the face of
the apparatus, k, k, l, l', aud m are contact blocks forming electrodes set into the
insulated face, and n, n', are spring tongues forming conductors attached to the arm i
and connected together, said tongues being insulated from the arm by a rubber
block o.
As the arm rotates the tongues come in successive contact with the several
conducting blocks and change the currents.
p, p, is an electro magnet, and Չ is a pivoted crank forming an armature which
operates in connection therewith. On the outer end of this crank is a pin q' which
passes through a slot of the top of the box and intercepts a pin r, on the under side
of the arm i, thereby holding said arm against rotation. When the magnet p, p, is
charged the armature is drawn back removing pin q' from the path of pin r and
allowing the arm to rotate.
5, s, is another electro magnet and t an armature pivoted at t¹ and provided with
an inclined lug t. The armature t is pressed forward by a spring u tightened by a
screw v. When the magnet is charged it overcomes the spring and draws the

page_text: armature back. w is an arm turning on a pivot w¹ connected with the base, the free
end of the arm engaging with the inclined lug of the armature. When in this
position the arm to rests in contact with a flat spring attached to an insulating
block y.
When the armature is drawn back by the magnet the arm w frees from
the spring and opens the circuit, and remains out of contact till arm w is struck by
a pin z on the shaft of the arm i which restores it to place by pressing it under the
lug t. The arm w is drawn from contact with spring by a coiled spring j. This
arrangement is for communication with the fire department only.
KC
The same arrangement is duplicated on the opposite side of the apparatus,
consisting of magnets, s¹, s', armature provided with inclined lug t, spring u',
screw, pivoted arm w³, contact spring x attached to insulating block y', and
coiled spring j', the whole operating to establish communication with the police or
other department.
The main circuit consists of two wires 1 and 2 said wires being provided,
respectively, with batteries G, H, or other sources of electricity. The terminals of
wire connect with the two electrodes k, k¹, on the face of the differentiating
apparatus, B and the terminals of wire 2 with the two sets of magnets a, a', of the
relay, A. The main line is provided with suitable street boxes P, and auxiliary
boxes L, the latter connected with circuits extending through buildings and provided
with thermostats and manuals. By means of these boxes signals are sent to the
various destinations over the same main line.
Under normal conditions the main line circuit is closed, the magnets of the relay A
are charged, and the armatures of the relay are drawn toward the magnets. But
any opening of the main circuit releases the armatures, which are then drawn
toward the posts b, 61, and the circuits at the central station are then ready to come
into operation. The circuits are as follows:-
A circuit extends from battery J, through wire 3 to armature c¹, thence, (when
the main circuit has been broken and said armature is in contact with post b),
through post b, wire 4, the register magnet F, causing it to operate the registering
apparatus, wire 5, magnet p, p, wire 6, (touching the conducting block m), back to
battery J. The energizing of magnets p, p, draws back armature g, removes pin q¹
from the path of pin r and releases the armi and allows it to rotate. Prior to this
time the tongues n, n', have remained in contact with the blocks k, k¹. They now
leave said blocks and pass to blocks and m.
Another circuit extends from battery K to the fire department.
This circuit is
from battery K through wire 7, upright e, armature c', wire 8, the magnet at the
fire station, and wire 9 back to battery K.
Auxiliary to circuit K is another circuit from battery K through wire 7, wire 10,
spring z, arm w, the pivot wl of said arm, through the metallic base of the differen-
tiating apparatus B, wire 11, wire 8, the magnet at the fire department, and wire 9
back to battery K.
Another circuit extends from the central station to the police department, from
battery through wire 12, upright e¹, armature c³, wire 13, the magnet at the police
station, wire 14, back to battery 1.
Auxiliary to this last circuit is a circuit from battery I through wire 14, the
magnet at the police station, wires 13 and 15, spring a, arm w³, the pivot to³, of
said arm, the base of the apparatus, wire 16, and wire 12 back to battery I.
The circuit K and its auxiliary just described are duplicates of the circuit I and
its auxiliary before described, one circuit connecting with the police department
and the other with the fire department.
The first action in opening and. then closing the main circuit through wire 2 is
to temporarily close the local circuit J, and thus release the time mechanism of
the differentiating apparatus and allow the arm i to rotate. The movement of
arm i brings tongues n, n¹, in contact with the blocks l, m, thereby forming a new
circuit, from battery J through wire 3, armature d (then in contact with the
upright of the relay magnet), wires 17 and 18, magnets 8, 8, wire 19, electrode !,
tongues n, n', contact block m, wire 6 back to battery J. The charging of

page_text: magnets s, s, draws back armature t and releases arm to allowing it to separate
from the spring a, thus breaking the circuit that previously existed by the contact
of the arm with the spring and extending through the base of the apparatus to
wire 11.
The further progress of arm i causes tongue n to leave block 1, breaking the
circuit just described, and brings tongues n, n', in contact with blocks l, m, and
forms a new circuit, from battery J through wire 3, armature c, upright e,
wires 17 and 20, magnet s', s1, wire 21, contact block 1, tongues n, n', block m, and
wire 6 back to battery J. The energizing of magnet s', s', draws back armature t³,
releases the pivoted arm to from spring thereby breaking the circuit that
previously existed leading from battery I through the base of the apparatus to
wire 16. This circuit, with its companion on the opposite side, are not
re-established until arms w and wo² are forced into contact with the armatures t
and t, by the pin 2 near the end of rotation of the arm i.
Under such conditions, with both circuits open, the circuit through the fire
department is from battery K through wire 7, upright e, armature c, c¹, (then
drawn back by the magnets a, a, and subject to any action of the relay), wire 8,
At the same time
the magnet at the fire station, and wire 9 back to battery K.
the circuit through the police station is from battery I through wire 12,
upright el, armature c³, c', wire 13, the magnet at the police station, and wire 14
back to battery 1.
It will be seen that the register F, the magnets at the fire station C and the
police station E, are each, through the armatures at the relay rendered susceptible
to the operation of the relay, and that the circuits are changed to send the signal
to one department or the other through the instrumentality of the differentiating
apparatus. By the use of this differentiating apparatus all signals which come to
the central station are recorded there and despatched to the proper destination,
such as the fire department or the police department, without one interfering with
the other.
Connected with the main circuit are auxiliary or sub-station boxes L, with lateral
loops or circuits 23 extending from the main line through buildings and provided
with thermostats and manual boxes, also street fire and police boxes P for
sounding alarms at the various stations. These boxes have many parts in common
with the differentiating apparatus. They have arms i, 3, and time move-
ments g', g. Each of the street boxes P have contact rims and blocks aº, a²,
a, a, set into the insulated face of the box, the outer rim a' having a break 63
just in advance of the starting point of the arm and the inner blocks a, a, having
a break as shown in Fig. 5. Each of the auxiliary or sub-station boxes L has
also contact rims and blocks a¹o, all, a¹², a¹³, a¹, a¹³, a¹, a¹7, a¹8, a1, a20, arranged in
five concentric rings on the insulated face of the instrument, with breaks between
them, as shown in the face view Fig. 6. Each of the arms of the street boxes P
has two outer spring tongues no, no, connected together and insulated from the
arm, and an inner separate spring tongue in electrical contact with the arm.
These three tongues rest in line with the three concentric rims of the contact
blocks so as to sweep over them. In like manner the arm of boxes L has two
pairs of tongues nº, n¹º, and n", n, the tongues of each pair connected together
and insulated from the arm, and a single intermediate tongue n" electrically
connected with the arm. These several tongues rest over and come in contact
with the five sets of conducting rims and blocks set into the face of boxes L.
The boxes and P have respectively electro magnets p², p, similar to the
magnets p, p, of the differentiating instrument 13; also pivoted armatures f, f*,
provided with inclined lugs, 17, also pivoted crank arms h³, 1, similar to the
crank arm in the differentiating instrument, and carrying stop pins at their
outer ends for restraining the swinging arms. The energizing of said magnets
removes the stop pins and repasses the arms in the same manner as in the
differentiating instrument. In addition to these features the crank arm * of
box P has an intermediate arm which projects inward in such position as to be

page_text: struck by the pin z', on the shaft of the..arm. shortly after starting, to re-set the
crank arm with the armature. Each of the boxes L, P, is also provided with a
wheel o' on the shaft of the arm,, against which bears a spring pressed up by a
screws, the object of which is to apply sufficient friction to the gearing of the
time mechanism to prevent back action. The exterior rims of the boxes also have
circuit breaking notches ², v³, arranged in two series in order to indicate numbers
for sounding alarms over the main line.
In addition to these devices the boxes P are started in operation manually by
pressing the finger on a knob t¹, Fig. 7, which removes a pin from contact with
the end of the arm and releases the latter. The finger knob stands a little
in the rear of the stop pin on the crank arm * so that when released by pressing
the knob the arm has a small degree of rotary movement and then is stopped by
striking the pin on the crank arm. The boxes L are each provided with two
finger knobs t, t¹³, similar to the knobs on the street boxes, by which means the
arm has two stops before reaching the restraining pin on the crank arm.
It is the design that should a signal be in the act of transmission from a box L
to the central station and should a street box P be operated while said box L is
in operation, the signal given from box L will not be interfered with, but at the
end of the operation of the said box L then the street-box P which has in the
meantime remained in suspension, will complete its operation automatically.
It is also the design that should a street box P be in operation and a manual
box or a thermostat in a building be operated, such operation will not start the
box L but when the street box has completed its operation then an additional
operation of a manual box or thermostat will operate the box-L.
It is also the design that should a manual box or a thermostat in the circuit
leading to the buildings protected by box L be operated, no other manual box or
thermostat in the same circuit will effect the operation of the box L started by the
first manual box or thermostat.
Another function of the box L is that immediately after its time movement
begins to operate, it closes a circuit and charges the magnet of the building gong
and causes said gong to ring till its time movement has run down, thus alarming
the inmates of the building. Immediately upon the operation of any one of the
signal boxes the circuit on wire 1 is immediately destroyed and is not restored
again under any circumstances till said signal box has ceased to operate and has
performed its function, at which time the current through wire 1 is restored again
and remains in that condition while the system is normal.
normal the current is from battery H through wire 1, wire 22, contact block a,
The box L being
tongues no, no, contact block a, wire 23 forming the circuit through the building,
block a, tongues n", n", block a", wire 24 and wire 1 back to battery H. To
complete the circuit the tongues n, n', of the differentiating instrument must be in
contact with the blocks k, k If from any reason wire 23 is broken, the current of
wire 1 being shut out of the building will seek another escape and will pass through
a shunt circuit as follows: From battery. H to wire 1, wire 25, resistance coil 26,
wire 27, electro magnet p³, wire 34, contact block a", tongues n", n", contact
block a", wire 24, and wire 1 back to battery.
10
The current through wire 2 is from battery G to the base of the instrument at *,
thence through the arm i, tongue n¹³, contact block a", wire 28, and wire 2 back
to battery G.
In case wire 23 of the building line is broken the magnet p² is energized, thus
attracting the armature f³ withdrawing the stop pin that restrains the arm and
the arm then commences to traverse the instrument.
commencement of the movement of the arm i¹the currents in both wires 1 and 2
For a short period after the
are absolutely broken and remain so until the arm in its progress brings tongue n
in contact with block a, tongue n' in contact with block a, and tongue no in
contact with block a¹. At this point it is to be determined whether the circuit in
the wire 23 has been interrupted by a signal or has been permanently destroyed as
in the case of a broken wire. In case it has been interrupted the current through

page_text: wire 2 is as follows:-From battery G through wire 2 to base of the instrument
at, arm i¹, tongue n", block al with which the tongue is then in contact, wire 29,
wire 23, contact block a18, tongues n¹º, nº, contact block a¹, wire 31, wire 2, back
to battery. In case wire 23 is broken there is no current until the further progress
of the arm has brought tongues n", n", in contact with the rings a¹ and a". In
the case of the immediate restoring of wire 23 the further progress of the
swinging arm brings tongue in contact with block a". The current is then from
battery G, through wire 2 to base of the instrument at 1, arm ¹, tongue n",
block a, wire 30, wire 23, block a¹8, tongues 10 and no, block a with which n° is
then in contact, wire 31, wire 2, back to battery. This current will energize any
electro receptive devices placed in wire 30.
The further progress of the arm i¹ brings tongues n", n¹³, in contact with the
rings a, a. From this time on during the movement of the arm the circuit in
the wire is the same whether the wire 23 in the building has been permanently
broken or simply interrupted by a signal. In either case the signal will be
transmitted to the central station. But in case the circuit has been interrupted by
a signal the signal will be transmitted to the central station and the fire and police
departments, while if permanently broken it will be transmitted to the central
station only.
The condition now is that the tongues n", n¹ are in contact with the rings a¹0,
respectively, and progressing around the instrument. The circuit of wire 2 is now
as follows:--From battery G through wire 2, branch wire (Fig. 6) 61, ring a",
tongues n¹³, n", ring a¹, wire 32, and wire 2 back to battery. Ring a", is notched
on its face in two series with the numbers indicating the box as shown at o'.
the arm progresses over the face of the instrument tongue n" engages said
notches and alternately opens and closes the circuit thus signalling the number of
the box at the central station over wire 2.
As
The further progress of the swinging arm brings tongues n³, n¹, in contact with
blocks a0, a18, tongue 13 in contact with block a"; and tongue n in contact
with block a¹².
The circuit now in wire 1, which is restored, is from battery H to wire 1,
wire 33, block a¹³, tongues n¹, n¹, block a¹, wire 24, wire 1 back to battery. The
current through wire 2 which has been maintained, is from battery G through
wire 2, the base of the instrument at 4, arm i¹, tongue n', block a¹, wire 28,
wire 2 back to battery. There the swinging arm is stopped by the first finger
knob t until the line man, having repaired the broken wire 23 puts the same in
condition for further service. The finger knobs for stopping the swinging arm are
simply to enable testing to be made without sounding an alarm at the central
station. After such testing has been made the swinging arm is released from the
knobs and allowed to move forward to the electrical stop on the end of the
cranked arm, when it is ready to be released by the electrical action as before
described.
Referring now to the street boxes P, in the normal condition the swinging arm i³
is held in a stationary position by the finger knob t¹. By pressing on this knob
the arm is released and moves forward till it strikes the stop pin on the end of
crank arm and is held there till the magnet p is charged, drawing back the
armature f which holds it. In the normal condition tongue ne rests on block a
and tongues n', no, on the rings a, a'. The current in wire 1 is from battery H to
the base of the instrument at 25, through said base, arm i³, tougue n³, block a³,
wire 34, wire 1, back to battery. The current through wire 2 is from battery G
through ring a, tongues no, no, ring a', and wire 2 back to battery.
The movement of the swinging arm from the finger knob to the electrical
holding pin removes tongue n³ from block a and brings it in contact with block a',
which forms a new circuit in wire 1, from battery H through wire 1, base of the
instrument at ³, swinging arm, tongue n³, block a', wire 36, magnet p', wire 37,
wire 34, and wire 1 back to battery. The current through wire 2 remains the same
as before, since the tongues n³, nº, have not left the rings aº, a'. The charging of

page_text: magnet p attracts the armature f^, releases crank arm h, removes the stop pin in
advance of the swinging arm and allows said arm to operate. The further progress
of swinging arm brings tongue n over the break 3 in the outer ring a', thereby
breaking the circuit in wire 2 leading to the relay at the central station. This
starts the differentiating instrument at the central station. The further progress
of the swinging arm brings tongues no, no, again in contact with rings a', a',
restoring the circuit through wire 2. As the arın progresses the tongue n passes
over a series of notches in the rim, alternately opening and closing the circuit and
signalling the number of the box at the central station, and through that to the fire
department. Now while this particular box is in operation as described, should
some other box on the main line be started by releasing its finger knob holding the
swinging arm, said arm of the second box could advance no farther than the stop pin
controlled by the electro magnet, and the current through wire 1 being destroyed
said electro magnet would not be charged and no action could take place. It would
so remain until the first box, having completed its signal and restored the current
in wire 1, energized the magnet in the second box, when the stop pin in the second
box would be withdrawn allowing the second box to give its signal following the
other. This is done automatically.
The police boxes are of the same construction as the fire boxes except that the
break at is of greater length than in the fire boxes. Fig. 5 shows one of the
police boxes. This break in the police boxes is of such length that the current in
wire 2 having been broken, and the differentiating instrument at the central station
having been started, the current in wire 2 will remain broken until such time as the
swinging arm of the differentiating apparatus shall have passed the point where
the fire department circuit is placed in position to receive signals from wire 2.
In such case the signals given at the police boxes are sent to the central station
and from there to the police station without being sent into the fire department.
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 combination of a two wire main circuit, signal boxes attached thereto,
a relay with which the terminals of one of the wires connect, a differentiating
apparatus provided with electrodes with which the terminals of the other wire
connect, and a circuit connected with the relay controlling the differentiating
apparatus, for the purpose specified.
2nd. The combination of a main circuit composed of two wires provided with signal
boxes, a differentiating apparatus having electrical connections with the main circuit,
and a lateral circuit extending therefrom provided with thermostats or manuals,
either or both, for the purpose specified.
3rd. The combination of a main circuit composed of two wires, with signal boxes
attached, a differentiating apparatus connected with the main circuit capable when
in operation of opening the circuit of one of the wires of the main circuit, thereby
arresting the action of one signal box while another is transmitting a signal, as
specified.
4th. The combination of a main circuit composed of two wires, a differentiating
apparatus having electrical connection with the main circuit, a signal box interposed
in the main circuit connected with both wires, a normally closed lateral circuit con-
nected with said box, provided with thermostats and manuals, either or both, so
constructed that the opening of a thermostat or tripping of a manual will open the
circuit and immediately close it again, thereby re-establishing the current through
the lateral circuit and main circuit, for the purpose specified.
5th. The combination of a main circuit composed of two wires, signal boxes of
different kinds attached, a central office apparatus with which the terminals of one
wire connect, a relay with which the terminals of the other wire connect, two
circuits extending to side stations, and a circuit controlling the action of the
central office instrument, so constructed that a box of either kind will transmit its

page_text: signal to its proper station without interference with any other box, for the purpose
specified.
6th. The combination of a main circuit composed of two wires with signal boxes
attached, a central office apparatus with which the terminals of one of the wires
connect, a relay with which the terminals of the other wire connect, a circuit con-
trolling the action of said central office apparatus and a circuit extending to a side
station, so constructed that under one condition a signal will be transmitted from
the main circuit over the station circuit and under another condition be arrested in
the central office, for the purpose specified.
7th. The combination, with a main circuit, and with a magnet controlling a
side circuit, of a differentiating apparatus provided with insulated electrodes,
respectively in connection with the main circuit and magnet, said differentiating
apparatus provided with a circuit breaker having an insulated contact point resting
in line with the electrodes, and operated by suitable means as and for the purpose
specified.
8th. The combination, with a main circuit and two side circuits, of a differentiating
apparatus provided with three insulated electrodes, respectively in electrical con-
nection with said three circuits, a circuit breaker with contact points in line with
said electrodes, and suitable mechanism for operating the circuit breaker, said
apparatus capable under one condition of placing both side circuits in electrical
connection with the main circuit, under another condition placing only one side
circuit in connection with the main circuit, and under another condition stopping
the signal at the main station as specified.
9th. The combination, with a main circuit, of a differentiating apparatus, two
insulated electrodes with which the terminals of the main circuit connect, a circuit
breaker provided with contact points which rest in line with said electrodes, and
means for giving motion to said circuit breaker, the whole so arranged as to close
the circuit through the inain line by the engagement of the contact points with the
electrodes and to open it by their disengagement, as described.
10th. The combination, with a main circuit composed of two wires, of a differentiating
apparatus, two insulated electrodes with which the terminals of one of the wires
connect, a circuit breaker provided with contact points which rest in line with said
electrodes, and suitable means for operating the saine, the whole capable when in
operation of opening one line of the main circuit and holding it open while a signal
is being transmitted over the other line, and closing it again after said signal has
been transmitted, as specified.
11th. The combination, with a main circuit, of a differentiating apparatus in
electrical connection therewith, provided with insulated electrodes and a circuit
breaker, a circuit connected therewith extending to a side station, a magnet which
controls the side circuit, a mechanism for operating the circuit breaker, and a local
circuit in electrical connection with said mechanism and the main circuit, for
controlling the mechanism as specified.
Dated this 17th dor of Iul 1201
ALLISON BROS.,
Agents for the Applicant.