IMPROVEMENTS IN ELECTRICAL SIGNALLING AND INDICATING APPARATUS FOR TELEPHONIC OR TELEGRAPHIC PURPOSES
Year: 1880

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention of
"IMPROVEMENTS IN ELECTRICAL SIGNALLING AND INDICATING APPARATUS
FOR TELEPHONIC OR TELEGRAPHIC PURPOSES." A communication from abroad
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 11th October 1880.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent
Agents, Southampton Buildings, London. "IMPROVEMENTS IN ELECTRICAL
SIGNALLING AND INDICATING APPARATUS FOR TELEPHONIC OR TELEGRAPHIC
PURPOSES." [A communication from abroad by Francis Blake, of Weston,
Massachusetts, United States of America.]
This Invention relates to electrical signalling and indicating apparatus for
telephonic or telegraphic purposes, and comprises the employment of a number of
synchronously-revolving dials under the control of a battery current upon a single
circuit, but acting automatically, each at a separate time, to ring a magneto-bell by
diverting through or grounding through the magneto-bell a magneto-current
generated at the central office, in combination with a device, under the control of
the operator at the central office, by which the automatic operation of the dial at
the central office may be made to coincide with the automatic operation of the dial
at either of the out stations.
It also comprises a device for shewing when the line is in use.
Also certain details of construction hereinafter specified.
In practising my Invention there is but a slight difference in the construction of
the instruments between those adapted to circuits in which the magneto-bell is to
be rung by diverting a magneto-current and those belonging to circuits in which
the magneto-current is to be grounded.
The instrument will first be described as belonging to a circuit of the former
kind.

page_text: I provide a wooden table, a brass frame for a train of wheels or ordinary clock-
work operated by a coiled spring, a dial upon a shaft revolving by the clockwork,
a governing fan, an electro-magnet mounted upon a block, and its armature rigidly
secured to a weighted bell-crank lever, which in turn is rigidly secured to a post,
rocking on a pin inserted in an arm projecting from the brass frame. The bell-
crank lever carries a catch which takes into a notch in the periphery of the dial,
and also a weight sufficiently heavy to lift the armature when not attracted by
the electro magnet. The dial has a second notch for a purpose to be hereinafter
mentioned.
When the instruments are used in circuits in which the magneto-current is to
be diverted through the bell the dial is of metal, and has a slot which is filled with
a hard india rubber plug.
When the instrument is to be used in circuits in which the magneto current is
to be grounded the dial is of hard india rubber, and the plug is of metal.
There is a brass post in front of the dial furnishing a bearing for a metallic shaft
carrying a hand or pointer. This hand is an electrode, and is furnished with a
platinum point, which is at all times in contact with the dial, the plug coming in
contact with it at each revolution of the dial. The shaft has a milled head, by
which it may be turned, and it is locked in any required position by a thumb
screw.
The dials should be graduated according to the number of stations, and each
station have its own number, its hand being turned to point to that number, and
there locked. That the hands may not get misplaced the milled heads may be
removed from the shafts to which the hands are attached at the out stations.
Each station, including the central station, is provided with a magneto bell
including a magneto electric machine on the main line; and the central station is
furnished with a battery and a key, the spring arm of which in its normal con-
dition is in contact with a plate, but which when depressed is in contact with
another plate.
Each station is provided with four screw cups, which, for convenience, are
numbered in one series from 1 to 12. At the central station cups 1 and 2 are
connected with the battery by wires, and cups 3 and 4 connect with a magneto-
bell by wires. Wires leading from cups 2 and 3 from one plate and from one
spool of the electro magnet unite. The other spool of the electro magnet is
connected by wire with a post, while another wire connects the brass frame,
including its clockwork with cup 4. A line wire connects cups 4 and 6, thus
uniting the central station with station No. 1. At station No. 1 wires connect
cups 5 and 6 with a break-circuit key belonging to the station to be used in giving
a return signal. Wires connect cups 7 and 8 with a magneto bell, and another
wire connects the two cups 6 and 7. A wire connects cup 5 with a spool of an
electro magnet, the other spool being connected by wires with a post, while another
wire connects the brass frame with cup 8.
A line wire connects stations No. 1 and No. 2 or cups 8 and 9. At station No. 2
wires connect cups 9 and 10 with the magneto-bell; wires connect cups 11 and 12
with a break circuit; a wire connects cup 12 with one spool of an electro-magnet;
a wire connects the other spool with a post, and another wire connects the brass
frame with cup 9; a wire connects cups 10 and 11, the latter cup being grounded,
as is likewise the spring arm of the key at the central station; another wire
connects the key with cup 1.
It is evident from the above description that at each station, including the central
station, the circuit is divided, one portion passing merely through the magneto-
bell while the other passes through the electro-magnet and the dial-instrument.
It should be added that the battery current is to be used simply for operating
the dial mechanism, the bells being rung by a magneto-current, and that the
resistances of the different branches of the circuit at each station are such that the
bell will not ring while the current is divided at that station.
When a single impulse of the battery current is sent through the line the

page_text: electro-magnet at each station attracts its armature, and thereby momentarily lifts
the stop from one notch in the dial and allows the dial to be revolved by the
clockwork, and the dial will continue to revolve until the stop resting upon the
periphery of the dial falls into the other notch.
The magneto bells are of ordinary construction.
It is obvious that the operator at any out station may call the central station by
generating a magneto-current with the generator of his magneto bell, provided he
can break the short circuit through his dial-instrument; but since his dial is under
the control of the battery current which is operated from the central office, it
becomes necessary to furnish the short circuit at each out station with a circuit-
breaker.
The said Invention is applied in a telephone-circuit consisting of a central and
three out stations as follows, that is to say:
The hand at the central station having been set to coincide with the hand at
station 1, to ring the central and No. 1 bells the operator at the central station
will close a switch and generate a magneto-current with his magneto generator.
The normal position of the hand at the central station is such that it is upon the
plug, and the short circuit is broken. If the operator at station I wishes to call
the central station he has merely to break his own short circuit and operate his
magneto-generator.
The switch at the central station is unnecessary, but is
provided in order that the central station may be called, even if through mistake
or otherwise the hand is not upon the plug.
When the said Invention is used for the magneto-current to be grounded through
the magneto-bells the dials are of hard india rubber and the plug of metal, and
there can be no current of either description through the bell of any station unless
the hand at that station is on the plug of the dial; and as the hand at no station
in its normal position is on the plug the battery current passes through the electro
magnets of the dial-instruments, and a single impulse will set the dials in motion.
When the circuits are arranged so that the magneto bells of the out stations are to
be rung by grounding through them the magneto current generated at the central
station there is no connection between the first named plate and the line, and in
the normal condition of the line the current is broken at the key. The devices
herein before described as circuit-breakers are then circuit-makers.
In this system as worked with grounded bells a resistance-coil is placed in the
main line beyond the farther station, of such power that a magneto-current
generated upon the line will pass through an intervening magneto bell to ground
whenever an opportunity offers, and this happens whenever the hand at a station
is on the plug.
It is obvious that this magneto-current can be established on the main line only
when the plug comes under the hand at the central station, and it is also obvious
that it will ground through the bell at that station the plug of whose dial comes
under the hand at the same time. When grounded bells are used the hand is upon
the plug at the central station or the switch is closed, so that the bell may be rung
by any person generating a magneto-current at any out station.
The second notch prevents the dial from making a full revolution, and when the
catch is in the first notch it is evident that the plug will be in a different position
from that which it occupies when the catch is in the first notch. Use is therefore
made of this device as a "line-in-use " signal. The operator at the central station
allowing all the catches to remain in the second notches while the line is in use,
the person at the out station, seeing that his own plug is out of its normal place,
will know that the line is in use.
It is obvious that in this system either station may be used as a central station,
provided it has a suitable battery and key, that is, the bell of any single station
may be rung from any other station.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Robert Lake in the Great Seal Patent Office on the
9th April 1881.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, .& Co., Patent
Agents, Southampton Buildings, London. "IMPROVEMENTS IN ELECTRICAL
SIGNALLING AND INDICATING APPARATUS FOR TELEPHONIC OR TELEGRAPHIC
PURPOSES." A communication from abroad by Francis Blake, of Weston,
Massachusetts, United States of America.
This Invention relates to electrical signalling and indicating apparatus for
telephonic or telegraphic purposes and comprises the employment of a number of
synchronously-revolving dials under the control of a battery current upon a single
circuit, but acting automatically, each at a separate time, to ring a magneto-bell by
diverting through or grounding through the said bell a magneto-current generated
at the central office, in combination with a device, under the control of the operator
at the central office, by which the automatic operation of the dial at the central
office may be made to coincide with the automatic operation of the dial at either of
the out stations.
It comprises also a device for shewing when the line is in use and details of
construction hereinafter described.
In the accompanying Drawing
Figure 1 is a plan, and Figure 2 a front elevation of an instrument employed in
carrying the said Invention into practice.
Figure 3 is a diagram, shewing how the circuit and branches are arranged when
the said Invention is applied to a group consisting of a central station and two
out stations, and the magneto bell is to be rung by diverting a magneto current
through it.
Figure 4 is a diagram for the further explanation of the working of the said
Invention.
Figure 5 is a diagram for the explanation of the working of the circuit when the
magneto-bells of the out stations are to be rung by grounding through them the
magneto-current generated at the central station.
There is but a slight difference in the construction of the instruments between
those adapted to circuits, in which the magneto-bell is to be rung by diverting a
magneto-current, and those belonging to circuits in which the magneto-current is
to be grounded.
I will first describe the instrument as belonging to a circuit of the former kind.
A, is a wooden table; B is a brass frame for a train of wheels or ordinary clock-
work C, operated by a coiled spring a; D is a dial upon a shaft c, revolved by the
clockwork; F is a governing fan; E is an electro-magnet mounted upon a block e;
H is its armature rigidly secured to a weighted bell crank lever l, which in turn is
rigidly secured to a post p rocking on a pin f inserted in an arm g projecting from
the brass frame B. This bell-crank lever carries a catch m, which takes into a
notch in the periphery of the dial D, and also carries a weight o sufficiently
heavy to lift the armature when not attracted by the electro-maguet. The dial D
has a second notch n¹ for a purpose hereinafter mentioned.
When the instruments are used in circuits in which the magneto-current is to be
diverted through the bell, the dial is of metal and has a slot, which is filled with a
hard india rubber plug r. When the instrument is to be used in circuits in which
the magneto-current is to be grounded, the dial D is of hard india rubber, and the
plug is of metal.
P is a brass post in front of the dial; this post serves as a bearing for a metallic
shaft t, carrying a hand or pointer v. This band is an electrode, and is furnished
with a platinum point, which is at all times in contact with the dial, the plug r

page_text: coming in contact with it at each revolution of the said dial. The shaft t has a
milled head, by which it may be turned, and it is locked in any required position
by a thumb screw h.
In the diagram, Figure 3, B represents the brass frame with its train of wheels;
D, the brass dial; P, the post in front of the dial; t, its shaft; v, the hand; and E,
the electro-magnet, all as in the instrument above described; B¹, D', P¹, t¹, v¹,
and E represent like parts of a similar instrument at station No. 1; and B², D³, P2,
t, v², and E, like parts of a similar instrument at station No. 2. The dials should
be graduated according to the number of stations, and each station should have its
own number, its hand being turned to point to that number and there locked. Το
prevent misplacement of the hands, the milled heads may be removed from the
shafts to which the hands are attached at the out stations.
Each station, including the central station, is provided with a magneto-bell
connected with a magneto-electric machine on the main line, and the central station
is furnished with a battery as indicated, and a key, the spring-arm of which, in
its normal condition, is in contact with plate 13, but when depressed, is in contact
with plate 14.
Each station is provided with four-screw cups, which for convenience are
numbered in one series from 1 to 12. At the central station the cups 1 and 2 are
connected with the battery by wires w¹, w², and the cups 3 and 4 connect with a
magneto-bell by wires w, w Wires leading from the cups 2 and 3 from plate 13,
and from one bobbin or spool of the electro-magnet E unite as shewn at x, and are
marked w³, w³, 207, 20s. The other spool or bobbin of the electro magnet E is
connected by the wire w with post P, while a wire w¹º connects the brass frame,
including its clockwork, with the cup 4. A line-wire w¹ connects the cups 4 and 6,
thus uniting the central station with the station No. 1. At station No. 1, wires
w and w¹s connect cups 5 and 6 with a break circuit key 8' belonging to the
station, to be used in giving a return signal, as will be hereinafter described.
Wires w¹ and w¹s connect cups 7 and 8 with a magneto-bell and wire w16 connects
the two cups 6 and 7. Wire w17 connects cup 5 with a spool of the electro-magnet E¹,
the other spool being connected by wire w¹8 with the post P', while wire w¹ connects
the brass frame B' with cup 8.
A line-wire w⁰ connects stations No. 1 and No. 2, or cups 8 and 9. At station
No. 2, wires w¹ and w" connect cups 9 and 10 with the magneto-bell. Wires
w23, w², connect cups 11 and 12 with the break circuit key s². Wire w connects
cup 12 with one spool of the electro-magnet E². Wire 2020 connects the other spool
with post P2, and wire w connects the brass frame B2 with cup 9. Wire W28
connects cups 10 and 11, the latter cup and the spring arm of the key at the central
station being grounded.
In the diagram 2020 represents the ground part of the circuit, and wire w³° connects
the key with the cup 1.
It is evident from the above description, that at each station, including the
central station, the circuit is divided, one portion passing merely through the magneto-
bell, while the other passes through the electro-magnet and the dial-instrument.
It should be added that the battery current is to be used simply for operating
the dial mechanism, the bells being rung by a magneto-current, and that the
resistances of the different branches of the circuit at each station are such that the
bell will not ring while the current is divided at that station.
The battery current is used as follows:-In the normal condition of the line it is
off, the arm of the key being in contact with the plate 13. In the normal condition
of the instrument at the central station, the hand is on the plug y, for a reason
hereinafter stated; but when the operator at the central station is about to put on
the battery, he turns the hand vso that it is no longer in contact with the plug 7,
but is in contact with the dial at the graduation thereof, which corresponds with
the position of the hand at the out station he wishes to call. Then depressing the
key and bringing in the battery, the circuit travels from the ground key through
line to to cup 1, through the battery by wires w¹ and w³ to cup 2, and to junction x,

page_text: where it divides, a portion passing by wire w8 through the electro-magnet, and by
wire w³, post P, shaft t, hand v, dial D, brass frame B, and wire w10, to cup 4, whence
it passes through the other stations to ground, as hereinafter shown. The other
portion of the current passes from junction x by wire wo to cup 3, and by wires w³
and w through the magneto-bell to cup 4, on to the other stations and ground.
From cup 4 the battery current travels by line wire w¹ to cup 6 in station No. 1,
where it again divides, a portion passing through wire w¹ to cup 7, whence passing
through the magneto-bell by wires w¹ and w15, it passes to cup 8 on to the next
station and ground, the other portion passing from cup 6 by wires w¹³, 12, through
the break circuit key s¹ to cup 5, and then through the dial instrument by w", E¹,
w18, P¹, t¹, 1, 11, B', wo, to cup 8 on to the next station and to ground. Entering
the next station at cup 9, the current divides, a portion passing through the magneto-
bell and on to grounded cup 11 by 221, 222, 10, and was, and a portion passing
through the dial instrument and break circuit key to grounded cup 11, by w, B³,
D³, v, t², P2, w26, E³, w25, 12, 24, 83, 23.
When a single impulse of the battery-current is sent through the line, the electro-
magnet at each station attracts its armature, and thereby momentarily lifts the
stop from the notch n in the dial, and allows the dial to be revolved by the clock-
work, and the dial will continue to revolve until the stop resting upon the periphery
of the dial falls into the notch n¹.
The magneto-bells are of ordinary construction, but my Invention may be more
easily understood if the connections of the magneto-generator and of the electro-
magnet which operates the bell-striker at each station are specified. They are as
follows:-
.
At the central station the wires w³ and w may be considered as a single-line
wire in which are located the coil of the electro magnet of the striker and a coil of
the magneto-generator in such manner that these coils form a part of the line. In
like manner the wires w¹, w15, may be considered as a single line wire at station 1,
and the wires w2, w21, as a single-line wire at station 2, each having located in it,
in like manner, corresponding coils. The circuits for the magneto-currents remain
the same as the battery circuits, and it follows that a magneto-current generated at
the central station may be divided at the cup 4, a portion being short circuited
through the dial-instrument, or it may all pass over line-wire w₁ to station 1.
In like manner a magneto-current, of whatever strength, which has passed over
wire to station 1, may be divided at cup 6, a portion being short circuited
through the dial-instrument and magneto apparatus at that station, or it may all
pass through the magneto apparatus at that station, and on over wire w20 to station
No. 2, where it may, in like manner, be partly short circuited or wholly passed
through the magneto apparatus to ground; but the resistances are such that the
bell at no station can be rung unless the full magneto current, wherever generated,
passes through the magneto apparatus of that station. It follows that if the
magneto current generated at the central station be divided at that station, it will
not ring its own bell, and it is obvious that if a magneto current generated at the
central station cannot ring its own bell, it will not have sufficient strength to ring
the bell of another station, whether the short circuit at that other station be
established or broken. In other words, the short circuits through the dial
instruments of both the central station and of an out station must both be broken
in order to ring the bell at the out station by a magneto-current generated
at the central station. Now the dials are all graduated, as before stated,
and each station has its number. The normal position of the hand at
each station is upon the figure of the dial designating the number of the station,
and at each revolution of the dial of any station when the hand v comes
in contact with the plug r, the short circuit through the dial is broken. It follows
that the operator at the central station, knowing the position of the hands at the
other stations, can set his own hand to coincide with any one of the other hands,
and that generating a magneto-current by his magneto-generator, he can send that
current through his own magneto-bell and through the magneto-bell of that station

page_text: whose hand so coincides with the hand at the central station. Those two bells will
ring, and those only, for at all other stations the magneto-current will be short
circuited. Accordingly, to call an out station, the operator at the central station
will set the hand of his dial to correspond with the hand of the dial at the station
he wishes to call, and send a single impulse of the battery current through the line
and then generate a magneto-current. The single impulse of the battery current
will set all the dials in motion, and the bells of the central station and the called
station will ring at the same instant, which will be when the plugs of the dials of
the two instruments come under their respective hands.
It is obvious that the operator at any out station may call the central station by
generating a magneto-current with the generator of his magneto-bell, provided he
can break the short circuit through his dial instrument, but since his dial is under
the control of the battery current, which is operated from the central office, it becomes
necessary to furnish the short circuit at each out station with a circuit-breaker, as
shown at 8', s³, and s³.
A simple illustration of this Invention as operated in a telephone circuit
consisting of a central and three out stations, is shown in Figure 4, in which the
full lines represent the main circuit passing through the magneto-bells as above
described, and also through the telephones, while the dotted lines represent the
short circuits containing the dials and break circuit keys.
As shown in Figure 4, the hand at the central station has been set to coincide
with the hand at station 1. To ring the central and No. 1 bells, the operator at
the central station will close the switch S and generate a magneto-current with his
magneto-generator. The normal position of the hand at the central station is
shown in dotted lines in Figure 4, that is to say, it is upon the plug, and the short
circuit is broken. If the operator at station 1 wishes to call the central station, he
has merely to break his own short circuit and operate his magneto-generator. The
switch S at the central station may not be necessary, but is provided in order that
the central station may be called even if through mistake or otherwise the hand is
not upon the plug.
When the magneto-current is to be grounded through the magneto bells
according to this Invention, as illustrated in Figure 5, the dials are formed of hard
india rubber and the plug of metal, and there can be no current of either
description through the bell of any station unless the hand at that station is on the
plug of the dial, and as the hand at no station in its normal position is on
the said plug the battery-current passes through the electro-magnets of the
dial-instruments, and a single impulse will set the dials in motion, as hereinbefore
described. When the circuits are arranged, as shown in Figure 5, there is no
connection between the plate 13 and the line, and in the normal condition of the
line the current is broken at the key. The devices shown at s¹, s², and 8³ in this
figure, instead of being circuit breakers, are circuit makers.
In this system as worked with grounded bells a resistance-coil is placed in the main
line beyond the farther station of such power that a magneto-current generated
upon the line will pass through an intervening magneto-bell to ground whenever
an opportunity offers, and this happens whenever the hand at a station is on the
plug.
The operation is as follows:-The operator at the central station wishing to call
another station, sets the hand at his station so that it points in the same direction
as the hand at the station he wishes to call. Touching the key he then sends a
single impulse through the line, setting all the dials in motion when he generates a
magneto current in his magneto machine.
It is obvious that this magneto-current can be established on the main line only
when the plug comes under the hand at the central station, and it is also obvious
that it will ground through the bell at that station the plug of whose dial comes
under the hand at the same time. When grounded bells are used the hand is
upon the plug at the central station, or the switch S is closed so that the bell may
be rung by any person generating a magneto-current at any out station.

page_text: The notch n¹ prevents the dial from making a full revolotion, and when the
catch m is in the notch n, it is evident that the plug r will be in a position
different from that which it occupies when the catch is in the notch n'. Use is
therefore made of this device as a "line-in-use" signal. If the operator at the
central station allows all the catches to remain in the notchs n¹, while the line is
in use the person at the out station, seeing that his own plug is out of its normal
place, will know that the line is in use.
It is obvious that in this system either station may be used as a central station,
provided it has a suitable battery and key, that is to say, the bell of any single
station may be rung from any other station.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,―
First. A series of synchronously-revolving dials controlled by a battery-current,
but acting automatically each at its own time, to ring a magneto bell by diverting
through or grounding through the magneto-bell a magneto current generated at a
distant office in combination with an automatic device under control of the operator
at the distant office, by which the automatic operation of the dial at the distant
office may be made to coincide with the automatic operation of either of the other
dials.
Second. The combination with a battery, suitable wires, and a magneto-bell, of
the hand v, the electro-magnet, the armature provided with a catch, and the dial
provided with a notch and plug, the dial or plug forming one electrode and the
band another electrode, substantially as described and for the purpose specified.
Third. At each of a series of stations on a telephone or telegraph line, a dial
revolved by its own clock-work and provided with two notches or stops located
relatively to each other and working in combination with the weighted armature
of an electro-magnet, substantially as described, to show at any and all of the
stations whether the line is or is not in use.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Seventh day of April, in the year of our Lord One
thousand eight hundred and eighty one.