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 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 e', e', two sets of swinging
armatures c, c¹, c², and c³, c, c, located at opposite ends of the magnets, and two
upright contact posts and b'. The armatures play between the magnets and the
posts.
The differentiating apparatus B, consists of a box provided with a conducting
base plate and an exterior face d, of insulating material.
is a time movement
or clockwork, and h an escapement connected therewith. 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, k³, 1, l, and m are contact blocks forming electrodes set into
the insulated face, and n, n', are spring tongues forming conductors attached to
the arm 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-maguet, and q is a pivoted crank forming an armature which
operates in connection therewith. On the outer end of this crank is a pin q¹
which passes through a slot of the top of the box and intercepts a pin r, on the
When the
under side of the arm i, thereby holding said arm against rotation.
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.
, 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

page_text: When
by a screw v. When the magnet is charged it overcomes the spring and draws
the armature back. to is an arm turning on a pivot w¹ connected with the base,
the free end of the arm engaging with the inclined lug t of the armature.
in this position the arm wrests in contact with a flat spring attached to an
insulating block 3. 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 on the shaft of the arm i which restores it to place by pressing
it under the lug t². The arm to is drawn from contact with spring . by a coiled
spring j. This arrangement is for communication with the fire department only.
The same arrangement is duplicated on the opposite side of the apparatus,
consisting of magnets s¹, s¹, armatures 3 provided with inclined lug t, spring u¹,
screw, pivoted arm to, contact spring attached to insulating block y', and
coiled spring, 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 1 connect with the two electrodes k, ¹, 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, b', 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 q, removes
pin g from the path of pin r and releases the arm i 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, arm w, the pivot w¹ of said arm, through the metallic base of
the differentiating 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 I through wire 12, upright el, armature e³, wire 13,, the magnet at the
police station, wire 14, back to battery I.
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 w³, of
said arm, the base of the apparatus, wire 16, and wire 12 back to battery 1.
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 brings tongues n, n', in contact with the blocks l, m, thereby forming a new
circuit, from battery J through wire 3, armature c', (then in contact with the
upright of the relay magnet), wires 17 and 18, magnets 8, 8, wire 19, electrode l,

page_text: The charging of
tongues n, n', contact block m, wire 6 back to battery J.
magnets &, s, draws back armature and releases arm to allowing it to separate
from the spring. 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, aud
forms a new circuit; from battery J through wire 3, armature c', upright e,
wires 17 and 20, magnet s¹, s, wire 21, contact block 1, tongues n, n², block m,
and wire 6 back to battery J. The energizing of magnet #1, s, draws back
armature, releases the pivoted arm o² from spring a 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 w² are forced into contact with the armatures t
and t, by the pin z 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, c', (then draw
back by the magnets a, a, and subject to any action of the relay), wire 8, the
magnet at the fire station, and wire 9 back to battery K. At the same time the
circuit through the police station is from battery I through wire 12, upright e',
armature, c, wire 13, the magnet at the police station, and wire 14 back to
battery I.
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
(which form the subject of my present invention) for sounding alarms at the various
stations. These boxes have many parts in common with the differentiating
apparatus. They have arms, 3, and time movements g', 9. Each of the
street boxes P have contact rims and blocks a, a, a, a, set into the insulated
face of the box, the outer rim a having a break 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 a¹0, all, a¹³, a¹³, a", a¹, a¹, a¹, a¹³, a, a, 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 is of the street boxes P has two
outer spring tongues no, no, connected together and insulated from the arm, and
These three
an inner separate spring tongue n in electrical contact with the arm.
16
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, no, and n¹, n, the tongues of each pair connected together and
insulated from the arm, and a single intermediate fongue 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 L and P have respectively electro-magnets p, p, similar to the
magnets p, p, of the differentiating instrument B; also pivoted armatures f³, f,
provided with inclined lugs f, f, also pivoted crank arms 2, *, 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

page_text: intermediate arm which projects inward in such position as to be struck by the
pin', 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 screw s³, 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,, attached 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 t, 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 s, t, 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. The box L being normal the current
is from battery H through wire 1, wire 22, contact block a, tongues no, no,
contact block a¹, wire 23 forming the circuit through the building, block a",
tongues n, n, block a¹, 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, k¹. 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 p², wire 34, contact block a", tongues n", n", contact
block a¹, wire 24, and wire 1 back to battery.
The current through wire 2 is from battery G to the base of the instrument
at z, thence through the arm 1, tongue n", contact block a", wire 28, and wire 2
back to battery G.
In case wire 23 of the building line is broken the magnet p³ is energized, thus
attracting the armature f withdrawing the stop pin that restrains the arm i¹ and
the arm then commences to traverse the instrument. For a short period after the
commencement of the movement of the arm i¹ the currents in both wires 1 and 2
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 a¹8. 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
13

page_text: in the case of a broken wire. In case it has been interrupted the current through
wire 2 is as follows:-From battery G through wire 2 to base of the instrument
at 24, arm i, tongue n", block a with which the tongue is then in contact, wire 29,
wire 23, contact block as, tongues no, 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 a
and all. In the case of the immediate restoring of wire 23 the further progress of
the swinging arm brings tongue n" in contact with block a". The current is then
from battery G, through wire w to base of the instrument at, arm i, tongue n",
block a wire 30, wire 23, block a¹8, tongues n10 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 i brings tongues n", n¹, in contact with the
rings a¹º, 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 department,
while if permanently broken it will be transmitted to the central station only.
The condition now is that the tongues n", n", are in contact with the rings a¹º, a",
respectively, and progressing around the instrument. The current of wire 2 is now
as follows: From battery G through wire 2, branch wire (Fig. 6) 61, ring a",
tongues n, n, ring a", 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 2. As
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.
The further progress of the swinging arm brings tongues n³, n10, in contact with
blocks a0, a18, tongue n¹ in contact with block a"; and tongue n¹ in contact with
block a¹³.
The circuit now in wire 1, which is restored is from battery H to wire 1, wire 33,
block a, tongues n", n", 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 2, arm i¹, tongue n, block a", wire 28, wire 2 back to
battery. There the swinging arm I stopped by the first finger knob t until the
lineman, 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 ³
is held in a stationary position by the finger knob t. 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 which holds it. In the normal condition tongue 8 rests on block a³
'and tongues n³, nº, on the rings a³, a². The current in wire 1 is from battery H to
the base of the instrument at 2, through said base, arm 3, tongue n³, block a³,
wire 34, wire 1, back to battery. The current through wire 2 is from battery G
through ring a, tongues n', 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 n 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 2, swinging arm is, 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 n', n°, have not left the rings a°, a'. The charging of magnet p₁
attracts the armature f*, releases crank arın h³, removes the stop pin in advance of.

page_text: the swinging arm and allows said arm to operate. The further progress of swinging
arm brings tongue no over the break 6 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 arm progresses the tongue nº 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. Not 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, with a main circuit composed of two wires, of a signal box
attached thereto, a tripping device connected with one wire, and suitable electrical
connections, the whole capable when in action, of opening said wire, transmitting a
signal over the other wire, and of closing the first wire again after transmitting the
signal, as and for the purpose specified.
2nd. The combination, with a movable arm forming a circuit breaker, of an
electro-magnet electrically connected with the main circuit, an armature provided
with a stop operating therewith, a crank arm engaging at one end with the stop on
the armature and provided at the other with a pin that acts as a stop to the circuit
breaker, an intermediate arm attached to the crank arm, and a pin attached to a
shaft for operating the intermediate arm, as described.
3rd. The combination, with a movable arm forming a circuit breaker, of an
electro-magnet electrically connected with the main circuit, an armature provided
with a stop connected therewith, a crank arm engaging with the stop of the
armature and provided with a pin that forms a stop to the circuit breaker, an
intermediate arm attached to the crank arm, a pin attached to a shaft for operating
the intermediate arm, and a manual stop in advance of the electrical stop for
holding the circuit breaker at a distance from the electrical stop, as and for the
purpose specified.
Dated