Improvements in Electric Signalling Apparatus.
Year: 1892

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by THE ELECTRIC SECRET SERVICE COMPANY,
of 45, Broadway, New York, United States of America.]
Improvements in Electric Signalling Apparatus.
I, HENRY HARRIS LAKE, of the firm of Haseltine Lake & Co., Patent
Agents, 45 Southampton Buildings in the County of Middlesex, 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 invention relates particularly to improvements in electric signalling
mechanism known in the art as individual call apparatus; such for instance as is
used in telephonic, telegraphic and analogous electric signalling systems for trans-
mitting a particular signal to an outlying station, which will indicate to the
subscriber or operator at that station, and to him alone, that he is wanted.
The objects of the invention are:-
First. To obtain greater certainty of operation of apparatus of this general nature
at all times, under all conditions of weather peculiarities of electrical circuit
disturbances and the like.
Second. The utilization of an answer-back signalling device, with the apparatus
at each operator's or subscriber's station which shall respond to the signal sent out
and only after it has been correctly received at that station.
Third. The construction and arrangement of a signalling apparatus which shall
be capable of transmitting individual signals to the individual outlying subscribers
or operators and shall also possess the qualification of enabling the transmitting
operator to call up all of the subscribers or operators at one and the same time.
Fourth. The accomplishment of the several features hereinafter referred to in
connection with the description of the apparatus and of its mode of operation.
These several objects are accomplished by the use of the apparatus hereinafter
described.
This invention belongs to that special type of individual call apparatus well
known in the art in which the signals transmitted are not only adapted to actuate all
of the receiving apparatus at the several outlying stations, but to cause the
mechanism located at those stations not wanted to assume their normal or original
conditions during some point of their forward advancement toward the completion
of the signal, while the mechanism at the station which is being called is caused to
pass completely through its operative phase, and indicate to the subscriber or
operator that he is wanted.
In the present invention use is made of a pre-arranged order of electrical impulses
sent over the line to positively impel a circuit closing device in a forward direction
to the completion of its phase, so that an alarm is sounded if the correct signal has
been transmitted; and an abnormally long break in the circuit is caused to give to
the circuit closing device two forward steps or movements.
During the forward advancement of the circuit closing device, energy is stored
up in the nature of a weight or spring for suddenly returning it, the said circuit
closing device, to normal position either at the completion of its phase or at any
intermediate point.
and
In the accompanying drawings
Figure 1 is a plan view of one of the improved individual call receiving devices,
Figure 2 an end view thereof.
Figure 3, a side view, while

page_text: Figure o is a diagrammatic view showing the operative portions of the circuits
main line, relay and an improved transmitter in connection therewith, while
Figure 7 is a diagrammatic and plan view illustrating a novel form of answer-
back signal in connection with an improved individual call apparatus.
It will be understood at the outset, that there would be in practice a number of
these individual call devices controlled by a single circuit with an individual answer-
back apparatus for each instrument.
In Figure 6 is shown one apparatus with a single transmitter, and in Figure 7,
the answer-back signal which may be applied thereto.
Referring to the drawings in detail,
A represents the base of the receiving apparatus, and N N1 N2 the side supports
or standards secured thereto in which the operative parts of the mechanism are
journalled.
M M and M2 are electro magnets attached to the base A and having cores
provided with magnetic extensions and 2 to the upper or extended ends of which
are pivoted armature levers a a¹ and a² provided with armatures extending over the
poles of the electro-magnets each having an independent and adjustable retractile
spring s s¹ s².
V is a shaft journalled in the side supports N N' and carrying a movable circuit
closer device or wheel W which is provided with a series of conducting teeth or
contacts at its outer edge and an inwardly projecting flange f with openings or
notches corresponding to the teeth or contacts a, this flange and its notches performing
the function of detent stops or notches.
Upon the opposite ends of the shaft V are located ratchet wheels R2 R3 having
their teeth so inclined as to receive the free ends of propelling pawls p, p² pivoted
respectively to the ends of the armature levers a a² and provided with retractile
springs s³ $4.
n2 is a shaft journalled in the standards N1 N2 and carrying near its centre an
arm and a curved rack R, the teeth of which mesh with a pinion p' upon a second
shaft journalled between said standards. (See Figures 1 and 2.)
Upon the same shaft with the pinion p is a gear wheel which meshes with an
additional pinion geared through intermediate shafting with an escapement wheel E¹
provided with an escapement pallet P carried by a shaft also journalled in the
standards N1 N2. The intermediate gearing between the escapement and the
rack R is provided with the usual pawl and click or ratchet mechanism which
permits the application of power through the arm h, rack R and pinion p' in one
direction, and the return of said rack under the stress of the armature retractile
springs in a reverse direction, the function of this apparatus being in the nature of
retarding mechanism, as will be more fully described in connection with the
description of the mode of operation of the instrument.
n is a rock shaft journalled in the side standards N N¹ and provided at its opposite
ends with a pair of arms l, curved outwardly at their upper ends so as to lie
behind the free ends of the pawls p p², as clearly shown in Figure 2.
Near the centre of this rock shaft n is secured at right angles thereto an arm k
located in the path of the free end of a pin po attached to the outer end of the
armature lever a¹.
m is a pin carried also by the free end of the armature lever al and adapted to
rest upon the upper surface of the inwardly projecting teeth of the flange for to
pass through the openings therein.
e e are electrical contacts, the former adjustable and carried by an upright
post K and the latter being carried by the free end of the armature lever a'.
pt * is a stop or pin carried by the movable circuit closing device or wheel W and
lying in the path of a fixed stop p³ attached to the base of the instrument; while t
is a spring located in the path of the pin p' when it is rotated in the direction of the
arrow shown in Figures 4 and 6.
W³ is a weight suspended from the shaft V by a cord e in a protecting tube or
guide, W', as clearly shown in Figure 4, the function of this weight being to rotate
2.

page_text: the circuit closing device or wheel W in one direction after the cord has been
wound up under the influence of the ratchet wheels R2 R3, pawls p p² armature
levers a a² and magnets M M² as will be described later on.
The electro magnets M M¹ M² are operatively connected with a local battery B¹A¹
situated in the local circuit te w connected through the armature a³ of the relay R
in the main line, the magnet M' being energized always when the armature a³ is on
its front stop the other magnets being energized only when the said armature is on
its back stop.
The circuit connections from the battery B' A' through these several magnets
and the magnets of the call bell or indicating apparatus B M will be pointed out in
connection with the description of the mode of operation.
Referring now to Figure 7 of the drawings, N³ represents my improved answer-
back signalling apparatus having a transmitter disc T2 operatively connected through
a clock driven train of gearing, not shewn, to a handle H, the interior mechanism
of the apparatus being substantially the same as that of well-known district call
boxes.
H2 is a cross bar or arm carried by the same shaft which supports the winding
handle H of the apparatus and is provided on one side with a curved projecting end
adapted, as the handle rotates in the direction of the arrow, to come into contact
with the free end of an electrical contact spring R', connected at its other end to
the conductor w², i being a fixed contact stop near the free end of the spring R' and
connected to the conductor w² on the other side.
d' is a portion of an escapement pallet operatively connected with escapement
mechanism, not shown, controlling the movement of the answer-back signalling
apparatus held normally by a pin 9 on the free end of an armature lever a³ which
armature is controlled in its movement by magnet M³ and a local circuit w¹.
is a pin located on the upper side of the armature lever a³ and in the path of
an enlarged portion of one end of the cross-bar or arm H².
t is a contact spring resting normally on a transmitter disc T2 of the
back signal and connected through the main line L to earth at E.
answer-
The local circuit connections with the local battery B' A' and the signalling
magnets B, M will be fully pointed out in connection with the description of the
mode of operation.
Referring now to Figure 6, T and T illustrate diagrammatically an improved
form of transmitter adapted to operate any one or all of a series of outlying
signal receiving apparatus of the nature or type described, at will.
In this figure of the drawings, only one signal transmitting disc T as applicable
is shown to one receiving instrument, the circuit closing device or wheel W of
which bears a fixed relation to the contacting teeth of the transmitter. That is to
say, the transmitting disc T in this instance is designed to transmit a signal
indicated by the numbers 1, 2, 3, 4, and 1, the series of teeth indicated on the left
being for the purpose of bringing the apparatus all to unison before starting.
It will be noticed that the circuit closing device or wheel W is provided with
projecting teeth adapted to make electrical contact with a contact spring t
and that the projections are of equal length, while the spaces between said teeth
are of variable length. Also that the notches or openings in the inwardly
extended flange f, of the wheel W are directly opposite these teeth, the
arrangement being such that so long as the proper sequence of impulses is
transmitted, the inwardly projecting portions of the flange flying in the path
of the pin or finger m (see Figures 1 and 2) will prevent the armature lever a¹
from being drawn forward to the extent of its full stroke and will also cause
the pin or finger m to act as a brake upon the wheel W. The projections 1, 2,
3, 4, and 1 of the transmitter T bear a fixed relation to the contact teeth & and
the intervening projecting teeth of the flange, which transmitter disc and its
corresponding receiving wheel or circuit closing device W differs from every other
one in the system in the arrangement or order of these parts so that each receiver
will respond only to its own transmitter.

page_text: The relation between all the transmitters, however and all their individual
receiving wheels or circuit closing devices W is such that if a regular series of
individual impulses be transmitted over the line following each other at stated
intervals, all of the signal receiving wheels or circuit closing devices will be
operated to the completion of their phases, thereby operating all of the signal.
mechanism.
In other words the contacting teeth 1, 2, 3, 4 and 1 may be arranged upon the
several transmitters in any preferred order reading from left to right, and so long
as the intervening spaces between said teeth are equal, it matters not what the
order of arrangement may be, provided each receiving wheel or circuit closing
device W be adapted to its own particular transmitter.
All of the transmitters might be arranged upon a common shaft connected with
the battery B, A and the switch S' shifted out of circuit with the transmitting
springs into circuit with any other transmitter, or to the universal transmitter T'
and contact spring 3, which, when actuated would call up all of the operators or
subscribers.
The operation of the apparatus is as follows:-
Referring first to Figure 6, of the drawings, the transmitter is presumably being
rotated from right to left in the direction of the arrow, the instruments having all
been brought to unison by a series of electrical impulses transmitted by the
several contacts shown on the left.
Under this condition of affairs, the transmitting contact spring t² rests upon the
first contact one of the transmitter and a single impulse is sent from battery BA
to line L through the relay R thus closing the local circuit w in all of the outlying
subscribers or operators apparatus thereby causing the electromagnet M¹ to
actuate its armature a' which causes the pin m to be drawn forward and to rest
upon one of the projecting teeth of the flange f. As the transmitter advances,
the circuit is broken between the points 1 and 2 for a definite interval of time, and
hence the relay R permits its armature a³ to be withdrawn under the influence of
the spring thereby interrupting the circuit of the local battery B₁ A' through
the local circuit and magnet M permitting its armature a¹ to be retracted
and the contact e to rest against the fixed contact e thus closing a second circuit.
from the battery B' A' in the direction of the tailless arrows through the wire w,
binding post B wire w¹, electro-magnet M*, polar extension of the magnet M'
armature lever a' contact points eel, electro-magnet M, binding post B² back to
battery thus energizing both electro-magnets M M2 and causing the armature
lever a² and its pawl p² to suddenly give to the ratchet wheel R³ and shaft V one
step forward, the stop p on the armature lever a² acting as a check to insure
always the same advancement of the ratchet wheel R³.
At the same time, the armature lever a and pawl p are retarded in their forward
movement under the influence of the same current and magnet M by reason of the
retarding action of the rack R4, pinion p and escapement mechanism. Hence
the ratchet wheel R2 is caused to advance one tooth under the action of the first
armature lever a² and pawl p² as already described, while the armature lever a is
retarded, so that if the current is continued through the magnet M, after the
magnet M2 has caused its armature lever to thus impart this single step, the
armature lever a and pawl p, will finally advance against the retarding influence of
the escapement mechanism and give to the ratchet wheel R2 an additional forward
step, so that if there is a break in the circuit through the relay R of considerable
length, said break will permit the two magnets M2 and M to give to the shaft V a
rotation due to the double action of the pawls p² and in sequence, as described,
each advancement of the shaft V causing the cords c to be wound thereon and
the weight W³ to be lifted.
Consequently the circuit closing device or wheel W has been now advanced
until the free end of the contact spring t¹ is in electrical connection with one of
the contact teeth so that while the contact spring t² of the transmitter is passing
over the space between the first and second set of contacts 2 and the circuit to

page_text: relay R is broken, the current of battery B¹ A¹ will be passing through the
magnet M only in the direction of the tailed arrows, thus giving to the shaft Va
forward movement after the magnet M has fully overcome the retarding influence
of the escapement mechanism, the magnet M having been shunted from the circuit
the current having taken, as already described, the short path by way of wire w
contact spring t circuit closing wheel or device W, wire we', armature lever a¹
through magnet M.
In other words, whenever the contact spring is resting upon one of the teeth.e
of the wheel W and the local circuit of battery B₁ A is broken at the relay
contact points, the magnet M2 will be shunted out of circuit and the magnet M will
impart to the shaft V a single forward step. When the contact spring of the
transmitter is at any point between any of the sets of transmitting teeth 1, 2, 3, 4,
and 1 on its circumference and when the local circuit is broken at the relay
contacts two forward steps will be imparted to the circuit closing device W,
provided the interval of time is sufficient to permit both of the armatures a² and a to
be actuated successively, this interval being dependent upon the transmitter solely.
It will thus be seen that for every positive impulse transmitted from the
battery BA through the relay R the local magnet M' is actuated, and that so
long as the pin m is caused to strike upon one of the teeth of the flange there
will be a continuous forward motion imparted to the circuit closing device W, and
this will continue as long as there is a fixed relation between the contacts of the
transmitter T, the corresponding teeth and notched flange f.
If the proper sequence of impulses and breaks occur, the circuit closing
device W will ultimately be rotated until the pin comes in contact with the
spring t, thereby closing the local circuit from the battery B' A' to the bell or
signal call apparatus B M as follows.
By the wire to binding post B, the wire contact spring tone of the long
contact teeth upon which it will rest when the pin p is rotated to the position
named thence through the wheel W pin pt contact spring wire w², binding
post B³, bell or signal magnets BM, wire back to battery, thus indicating to
the operator or subscriber that he is wanted.
Should any order of impulses be transmitted to line other than that designed to
operate the particular receiving apparatus at sometime during the forward progress
of the wheel W or circuit closing device the pin m on the armature lever a would
be drawn forward through one of the notches in the flange thereby permitting
the pin p carried at the outer end of the armature lever a¹ to impart a forward
motion to the arm & carried by the rock shaft n, and in turn causing the releasing"
devices or rods I, I¹ to release the pawls pp from the ratchet wheels R2 R³ thus
permitting the weight W³ to descend and suddenly rotate the circuit closing device
or wheel W in a reverse direction until the stop p rests against the fixed stop p³.
Each time, therefore, that the pin or finger m passes through one of the notches
in the flange f, the circuit closing device or wheel W will be automatically and
instantly returned to its starting point.
The operation of the answer-back signal illustrated in Figure 7 of the drawings
will now be described.
This device will only operate in the event of the transmitted signal having been
correctly received by the operator or subscriber who it was intended to call, and
is arranged directly in the main or signalling circuit L, so that after the signal
has been transmitted to the particular subscriber or operator wanted, a return
signal indicating that fact will be received by the operator who sent out the call.
The circuit closing device or wheel W is the same as in the other figures of the
drawing, and is shown as having been advanced almost to the completion of its
phase through the agency of the transmitter in the manner already described.
When this phase is completed and the pin rests upon the spring t with the
spring upon the tooth r', a circuit is closed from the local battery B' Ai as
follows:
By the wire w, binding post B, wire 20³, contact spring t, tooth r', wheel W;"

page_text: pin, springt, wire w", binding post 13°, wire, magnet M, wire back TO
battery. This causes the armature a³ of the magnet M³ to be drawn downward
and to release the end of the escapement pallet from its bearing against the
ping, thereby permitting the mechanism in the signal box N³ to impart motion to
the handle H in the direction of the arrow and to the signal disc T2 in the
direction of a second arrow, causing the circuit to be interrupted a definite number
of times as will be clearly understood, the bar H2, in the meantime passing over
the pin thus holding the armature lever as in its lower position, so that
although the circuit may be interrupted between the pin pt and springt by the
restoring device after the magnet M³ is demagnetized, the mechanism of the signal
box N³ will be permitted to rotate the signal disc T through its complete phase
and carry the curved end of the arm H2 forward until the spring R₁ is forced
into electrical contact with the fixed contact i, thereby permanently closing the
bell or signal circuit through the signalling magnets B M, conductors w²w and w
and causing the signal bell to be rung until the attendant restores the answer-back
mechanism to its normal or locked position, as now shown.
When it is desired to call up all of the subscribers or operators, the switch S¹
is placed in connection with the universal transmitter T¹, and after the unisoning
impulses have been sent in the manner already described, the several contacts on
the transmitter being arranged in regular order or regularly spaced, there being
eleven such contacts equal in number to the sum total of all of the operating
contacts in each one of the transmitters as this transmitter rotates from right to
left, there will be sent to line eleven equally spaced impulses; and inasmuch as all
of the circuit closing wheels or devices W embrace contacts a so spaced and
provided with notches or teeth correspondingly spaced with relation to the
individual transmitters, all of these signal receivers will pass completely through
their phases for the eleven equally spaced impulses, so that all of the signal
receiving apparatus at all the stations will respond to this single transmitter.
The invention is not limited to the specific mechanism herein shown and described
for accomplishing the results attained. It is believed to be broadly new to cause
a movable circuit closing device to be positively advanced step by step and to
simultaneously store up energy for restoring it instantly to its original position,
when released, either at the end of its phase or at various intermediate points, one
portion of the step by step mechanism being operatively connected with a retarding
mechanism which prevents it from acting for simple current impulses, and the claims
hereafter made are in this particular of such generic scope as to include broadly
mechanism for accomplishing this result.
It is believed to be broadly new to provide an answer back signalling apparatus
for each individual receiving instrument, which answer-back signalling instrument
will respond only when that particular receiver has been actuated, said answer-
back apparatus, however, being located directly in the main circuit so that it
actually breaks or interrupts the main circuit through all of the relays in the
line.
Answer-back mechanism is old in connection with fire and analogous signalling
systems adapted to respond to special signals sent over a telegraph line, and it is
also old to combine an answer-back signal with individual call mechanism, the
answer-back apparatus being located in a derived circuit around the signal receiving
instruments.
Apparatus has also heretofore been devised in which a movable circuit-closing
device is advanced through its phase to operate a signal receiver through the
agency of two electro-magnets, one of which operates for simple current impulses,
and the other for currents of abnormal length both of which act to store up
energy for returning the circuit-closing device to its normal position, either at the
end of its phase or at intermediate points through the agency of a third electro-
magnet. In the aforesaid apparatus, however, two local batteries are used and the
apparatus is made dependent upon the transmission of what is known of as
"dot"
and "dash" impulses, while the described apparatus is made to depend for its

page_text: operation wholly upon the transmission of "dot" impulses of equal length, and
the second of the two propelling magnets is operated only for a prolonged break
in the transmitting circuit, and the claims hereinafter made are not designed to cover
or include any apparatus which is operated other than by current impulses of
substantially the same length it being one of the essential features of this invention
that the evil effects of currents of the aforesaid variable nature are avoided.
It is believed to be novel to provide a universal transmitter for a series of
individual signal receiving apparatus, each responsive only to its own transmitter
but all responsive to the aforesaid universal transmitter and to the combination
of said universal transmitter with a series of individual transmitters and individual
receiving apparatus each adapted to respond only to its own transmitter or the
universal transmitter; and the following claims in this particular are designed to
be of such scope as to include receivers which may be actuated each individually
by a pre-arranged code with a Morse key.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed as communicated to me by my
foreign correspondents, I declare that what I claim is :-
1. An individual call apparatus having a movable circuit closing device opera-
tively connected with the armatures of two electro-magnets, adapted each to give
it a forward step by step movement, a mechanical retarding device for preventing
one of said magnets from acting for simple closures of the signalling circuit and a
signal receiver in circuit with the circuit closing device, one of the propelling
electro-magnets acting to advance the circuit closer for simple current impulses
and the other only for abnormal breaks of the circuit, substantially as described.
2. An individual call apparatus provided with a movable circuit closing device,
an electro-magnet for controlling the direction of its motion and two additional
electro-magnets for controlling its forward advancement in combination with a source
of energy as a weight for returning the circuit closing device to normal position,
one of the propelling electro-magnets having its armature attached to a retarding
mechanism which permits said armature to impart to the circuit closing device a
forward motion only on an abnormal break of the current, substantially as
described.
3. An individual call apparatus provided with a movable circuit closing device
operatively connected with a local signalling instrument and electro-magnetic means
for giving the said circuit closing device positive forward motion and simul-
taneously storing up energy for moving it in the reverse direction and additional
electro-magnetic means for releasing it at the end of its journey or at intermediate
points and thereby allowing it to be returned to normal position, the operating
electro-magnet and signalling instrument being controlled by a single local battery,
substantially as described.
4. An individual call apparatus having a movable circuit closing device,
electrically connected to a local signal or alarm mechanism, electro-magnetic step
by step apparatus adapted to give to the circuit closing device a positive step by
step advancement, a source of energy operatively connected to the circuit closing
device and adapted to be brought into play as the latter advances, an additional
electro-magnet and intermediate mechanism which releases the step by step
mechanism at the end of its phase or at intermediate points and permits the circuit
closing device to be restored to normal position, all of the local connections being
through a single local battery, substantially as described.
5. An individual call apparatus provided with a movable circuit closing device
operatively connected to a local signal mechanism; electro-magnetic means for
giving to the circuit closing device forward advancement either one or two steps
as desired, and additional electro-magnetic means for controlling the application of
the first named electro-magnetic means, all of the electro-magnets and the local
signalling mechanism being under the control of a single local battery, substantially
as described.

page_text: 6. An individual call apparatus provided with a local signal or alarm mechanism;
a movable circuit closing device connected through a local battery with said alarm
mechanism; two electro-magnets having ratchet and pawl mechanism adapted to
give to the circuit closing device forward advancement, and a third or controlling
electro-magnet having mechanical and electrical connections whereby the circuit
closing device is positively advanced step by step, one of the propelling electro-
magnets having retarding mechanism operatively connected with its armature lever
for preventing the advancement of the circuit closing device for simple current
impulses and permitting it to act only on abnormal ruptures of the circuit,
substantially as described.
7. The described electro-magnetic means for giving forward advancement to a
circuit closing device consisting of two electro-magnets electrically united in one
circuit and having armatures provided with pawls adapted to act upon ratchet
wheels carried by the same shaft which carries the circuit closing device, one of
said armatures being connected to an escapement retarding mechanism whereby
either one or two steps may be imparted to the ratchet wheels either for a single
electrical impulse or an abnormal break, substantially as described.
8. A step by step mechanism consisting of a rotary shaft carrying a pair of
ratchet wheels; two electro-magnets provided with armature levers which carry
pawls adapted to actuate said ratchet wheels, one of said armature levers being
connected to a mechanical retarding device and both magnets being included in a
single circuit whereby the circuit closing device is advanced either by current
impulses or abnormal breaks, substantially as described.
9. In an individual call system a transmitter adapted to transmit a pre-arranged
order of electrical impulses followed by spaced breaks in combination with an
electromagnet adapted to respond to said impulses and a pair of electro-magnets
which respond only for the breaks the armatures thereof being operatively con-
nected to a movable circuit closer and adapted to impart to it a positive forward
motion of either one or two steps at each break dependent upon the length thereof,
all of said magnets being controlled by the same local battery, substantially as
described.
10. In an individual call system a transmitter adapted to transmit a pre-arranged
code in the nature of makes and breaks in an electrical circuit including a relay
magnet; a local electro-magnet included in a local circuit controlled by said
relay a pair of electro-magnets operatively connected to the same local circuit
through step by step mechanism with a movable circuit closer and electrically con-
nected through contacts with the armature of the first named magnet, in combination
with a retarding device for the armature of one of said electro-magnets and a
source of power as a weight connected to the shaft which carries the circuit closer,
substantially as described.
11. In an individual call system one or more main line relays located in a single
main line; local electro-magnets one for each relay; a pair of electro-magnets
having electrical circuit connections through the armature of the first named local
electro-magnet and mechanical and electrical connections between all of said
electro-magnets and a movable circuit closing device operatively connected a local
signalling instrument, all of the local electro-magnets being controlled by a single
local battery, substantially as described.
12. In an individual call system a local alarm apparatus or signalling instrument
at each of a series of stations provided with mechanism adapted to actuate it, in
combination with a series of individual transmitters adapted to actuate each its
own signalling instrument only, and an additional transmitter provided with a series of
make and break contacts adapted to actuate all of said alarm or signalling instruments
simultaneously, the transmitters and receivers being operatively connected in a
single circuit and the additional transmitters normally out of circuit therewith,
substantially as described.
13. In an individual call system a series of alarm or signalling instruments
located one at each of a series of outlying stations connected by a single electrical

page_text: circuit; a movable circuit closing device operatively connected with each alarm
signalling instrument and mechanism for causing it to complete a local circuit
through the signalling or alarm mechanism in combination with a multiple trans-
mitter provided with a transmitting disc for each alarm mechanism and an
additional transmitting disc having a series of make and break contacts adapted
to cause all of the alarm mechanism to be actuated simultaneously, substantially as
described.
14. A signal receiving instrument responsive only to a pre-arranged call in com-
bination with an answer-back signalling transmitter operatively connected with the
receiving instrument and located directly in the main line, and circuit connections
whereby the receiving instrument is actuated to the completion of its phase, after
which an answerback or return signal is automatically transmitted to the trans-
mitting station, substantially as described.
15. In an individual call system an alarm mechanism or signal receiving apparatus
located one at each of a series of outlying stations and each responsive only
to a pre-arranged call or signal in combination with an answer-back signalling
mechanism located at each station directly in the main line and adapted to auto-
matically transmit a signal over the line after the alarm mechanism has been
actuated, thereby indicating to the transmitting operator that his signal has been
correctly received, substantially as described.
16. In an individual call system a signal receiving instrument or alarm mechanism
located in a normally open local circuit; electro-magnetic means adapted to close
said local circuit for a pre-arranged call or signal, combination with an answer-
back transmitting instrument controlled by the same local circuit but located
directly in the main line and adapted to automatically indicate to the transmitting
operator that his signal has been received, substantially as described.
17. In an individual call system a series of relays located in the main line; a
series of movable circuit closing devices provided with electro-magnetic means for
causing them to close local circuits through alarm mechanism; an answer-back
signalling mechanism for each relay provided with an electro-magnet for bringing
it into operation; the transmitter of each answer-back mechanism being located
directly in the main circuit substantially as described.
18. In an individual call system a series of relays located in a main line; an
individual call apparatus for each relay; a movable circuit closing device opera-
tively connected in a local circuit with each call apparatus; electro magnetic
means for advancing the circuit closing devices through their complete or operative
phases; an answer-back signal for each call apparatus located directly in the main
line circuit and operatively connected through a local circuit with the circuit
closing device, whereby, as each individual call is received, its answer-back signalling
mechanism automatically indicates the fact by transmitting a return signal, substan-
tially as described.
19. In an individual call apparatus the combination of the following elements;
a movable circuit closing device, carried by a rotary shaft, which carries also a
weight suspended by a cord and a pair of ratchet wheels; an electro-magnet
provided with an armature having circuit connections through two additional
electro-magnets each provided with an armature and a propelling pawl and
adapted to impart to the rotary shaft forward motion; a releasing device in the
nature of a pin on the free end of the first named armature, and a rock shaft
carrying three arms and adapted to release the pawls from the ratchet wheels,
when the first named armature is drawn through its full stroke.
Deted this 24th day of May 1892
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.