IMPROVEMENTS IN MEANS AND DEVICES FOR TELEGRAPHIC AND TELEPHONIC PURPOSES to be as follows
Year: 1885

page_text: I ABNER MULHOLLAND ROSEBRUGH of 121 Church Street in the City of Toronto
in the Province of Ontario Canada but at present residing at 16 Norfolk Street
Strand in the County of Middlesex Surgeon do hereby declare the nature of my
Baid Invention for "IMPROVEMENTS IN MEANS AND DEVICES FOR TELEGRAPHIC AND
TELEPHONIC PURPOSES to be as follows:
"
My Invention relates to means whereby I am enabled to utilise a telephone
circuit or part thereof to form a second telephone circuit or part thereof thus
enabling me to use fewer lines than has heretofore been necessary: and my said
Invention also comprises the arrangements of instruments and of circuits requisite
to enable communication to be carried on with certainty and independence both in
calling up and in speaking. To effect this object I make use of, telephonic instru-
ments having double coils some of them wound or connected differentially others
wound or connected non-differentially, the two portions of the coils being respec-
tively inserted in the outgoing and returning wires of a single metallic circuit.
The differentially connected instruments at one end speaking to the differentially
connected instruments at the other end, and the non-differentially connected
instruments at one end operating simultaneously to the non-differentially connected
instruments at the other end without interference of the differentially and non-
differentially connected instruments the one with the other. I may use one of
these two wires as a simultaneous independent telegraphic line in the manner
indicated in the Specification of Letters Patent N° 1477 of 1879. Or I may
utilize two parallel lines having earth connections at each end of each and by
inserting at each end of each a direct circuit working. Telephone consisting of
transmitter and receiver either separately or combined with or without a battery
and by protecting the lines from the material interference of these two parallel
systems by the application of the device which I hereinafter term a "anti-induction
device" and which I hereinafter describe and in the line beyond the anti-induction
device I insert at each end of either or both of the parallel lines telephones capable
of working an induction circuit either of those at the one end being able to speak
to either of those at the other end without interfering with the sets.protected by

page_text: the anti-induction device. I have thus three sets of simultaneous and independent
telephones working on two parallel lines and I may further utilise either of the
said lines for simultaneous telegraphic uses either as described in the Specification
of the aforesaid Letters Patent or by switching out one set of telephones and
switching in the opposite telegraphic instruments or by applying my "anti-
induction" device.
"
My Invention further consists in applying the same "anti-induction device to
one of two parallel wires one of which is the ordinary telephone wire, the other
being a telegraph wire, thus preventing interference between the telegraph and
the telephone when used simultaneously. My "anti-induction device" consists
of a condenser of large capacity or its equivalent arranged as a shunt in the one
case to the receiver and transmitter of the direct acting telephone or in the other
case to the key and the receiving telegraph instrument or relay or some part or
parts thereof. In the case, for example, of Morse telegraph instruments in the
telegraph line I arrange the condenser or equivalent as shunt to the key and to the
electromagnet or to one or both coils thereof.
I may so apply condensers to the telephone line as to enable me to utilize as a
return wire a neighbouring parallel telegraph line without anti induction devices
being attached to the latter and without grounding. This I accomplish by con-
necting the return wire to the Telephone line through suitable condensers or other
equivalent or through a high artifical resistance the Telephones being included in
the circuit on either side of the condenser; any electromagnet at an intermediate
station on a telegraph line being bridged by a condenser. Any manipulator or key
at an intermediate station on a telegraph line must however be bridged by shunting
the manipulator and the adjacent receiver or other electromagnet by the anti-
induction device hereinbefore mentioned.
My "anti-induction device" may also be applied to a single telegraph line.
(shunting each set of Morse instruments with condensers of large capacity) so as
to render said telegraph line available for telephonic purposes without grounding
the line. In this case the ordinary telephonic instruments such for example as the
"Bell and Blake set togetlier with the ordinary magneto-call bell are attached
simply as a shunt to the receiving telegraph instrument or to the electro magnet
of the saine at either end of the line.
"
In this part of my Invention is also comprised a further adaptation of my
"anti-induction device" to two parallel telegraph lines enabling me to use them
together for telephonic communication as a metallic circuit whilst employing one
only of them for calling on the ringing up circuit, the anti-induction device on
that line being adapted therefore by having larger condensers provided. Each line.
is provided with anti-induction device having suitably large condensers as herein-
before described at each end the two lines are then united at each end by a bridge
containing the telephone and a condenser or its equivalent the magnet call bell
being connected to either line and working through the large condenser of the
"anti-induction device."
For further carrying out the preceding combinations I provide special adaptations
for calling up the telephone operators without interfering with either Telephone or
telegraph and according to one method of doing this I connect the magneto-call
bell to the secondary coil of an induction coil the primary of which is inserted in
the line between the line and the "anti-induction device" the telephone being
either in the line or connected in the usual manner to the call apparatus with the
customary switches.
.
Another method of realizing this object consists in calling by the magneto
generator through the anti-induction device, the appropriate receiving bell being
inserted with the condenser in the shunt part of the anti-induction device.
Another arrangement for carrying out this part of my invention consists in
combining a large and a small condenser in a modified anti-induction device so
arranged that the small condenser may be shunted from the circuit during signalling

page_text: the large condenser conveying the strong signal currents but the small condenser
being necessary to protect the telephone from telegraph induction.
For uniting two separate telephone lines, each of which has been independently
duplexed with a telegraphic apparatus as hereinbefore described I employ an
arrangement of condenser or condensers or their equivalent so that the two lines
become one for telephonic purposes, the intermediate apparatus serving as a
translating device.
A differentially wound telephone receiver may be inserted in the main line of
a telegraphic circuit, one coil of which is connected to the anti-induction device
and is so arranged as to be responsive to telephonic or induced current signals but
neutral to voltaic or battery currents.

page_text: Telephonic Purposes.
I ABNER MULHOLLAND ROSEBRUGH of 121 Church Street in the City of Toronto
in the Province of Ontario Canada, but at present residing at 16 Norfolk Street
Strand in the County of Middlesex Surgeon 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 to means and devices for superimposing secondary or
induced currents upon the ordinary telegraph circuit without interference and is
designed as an improvement upon the Invention described in Letters Patent
No 1477 of 1879. The first part of my Invention relates to means whereby
I am enabled to utilize a telephone circuit or part thereof to form a second
telephone circuit or part thereof, thus enabling me to use fewer lines than has
heretofore been necessary.
I may utilize two parallel lines having earth connections at each end of each and
by inserting at each end of each a direct circuit working telephone consisting of
transmitter and receiver either separately or combined with or without a battery
and by protecting the lines from the mutual influence of these two parallel systenis
by the application of the device, which I hereinafter term an "anti-induction"
device, and which I hereinafter describe, and in the line beyond the anti-induction
device I insert at each of either or both of the parallel lines, telephones capable of
working on induction circuit, either of those at the one end being able to speak to
either of those at the other end without interfering with the sets protected by the
anti-induction device. I have thus three sets of simultaneous and independent
telephones working on two parallel lines and I may further utilize either of the
said lines for simultaneous telegraphic uses, either as described in the Specification
of the aforesaid Letters Patent or by switching one set of Telephones and switching
in the appropriate telegraphic instruments or by applying my anti-induction device.
The second part of my Invention consists in applying the same anti-induction
device to one of two parallel wires one of which is the ordinary telephonic wire
the other being a telegraphic wire thus preventing interference between the
telegraph and the telephone when used simultaneously. My "anti induction
device" consists of a condenser of large capacity or its equivalent arranged as a
bridge or shunt in the one case to the receiver and transmitter of the shunt acting
telephone or in the other case to the key, and the receiving telegraph instrument
or relay or some part or parts thereof. In the case for example of Morse telegraph
instruments in the telegraph line I arrange the condenser or equivalent as a bridge
or shunt to the key and to the electro magnet or to one or both coils thereof.
My anti induction device may also be applied to a single telegraph line (shunting
each set of Morse instruments with condenser of large capacity) so as to render said
telegraph line available for telephonic purposes without grounding the line. In
this case the ordinary telephonic instruments such for example as the "Bell and
Blake" set together with the ordinary magneto call bell are attached simply as a
.

page_text: bridge or shunt to the receiving telegraph instrument or to the electro magnet of
the same or to a special electro magnet inserted as a block to the secondary
currents at either end of the line.
In this part of my Invention is also comprised a further adaptation of my anti
induction device to two parallel telegraph lines enabling me to use them together
for telephonic communication as a metallic circuit whilst employing one only of
them for calling on the ringing up circuit the anti induction devices on that line
being adapted therefor by having large condensers provided as a bridge or shunt to
the morse instruments.
Each line is provided with an anti, induction device having suitable large
condensers as hereinbefore described at each end and the two lines are then
united at each end by a bridge containing, the telephone and a condenser or its
equivalent the magneto call bell being connected to either line and working
through the large condenser of the anti induction device-For further carrying
out the preceding combinations I provide special adaptations for calling up the
telephone operators without interfering with either telephone or telegraph and
according to one method of doing this I connect the magneto call bell to the
secondary coil of an induction coil the primary of which is inserted in the telegraph
line between the line and the anti induction device the telephone being either in
the line or connected in the usual manner to the call apparatus with the customary
switches.
Another method of realizing this object consists in calling by the magneto
generator though the anti induction device, the appropriate receiving bell being
inserted with the condenser in the shunt part of the anti induction device.
Another arrangement for carrying out this part of my Invention consists in
combining a large and a small condenser in a modified anti induction device so
arranged that the small condenser may be shunted from the circuit during
signalling the large condenser conveying the strong signal currents but the small
condenser being necessary to protect the telephone from telegraph induction!
For uniting two separate telephone lines each of which has been independently
duplexed with a telegraphic apparatus as hereinbefore described I employ an
arrangement of condenser or condensers or their equivalent so that two lines
become one for telephonic purpose the intermediate apparatus that is to say the
said condensers or their equivalent serving as a repeating or translating device.
In connection with my anti induction device I may use a differentially wound
telephone receiver inserted in the main line of a telephonic circuit, one coil of
which is connected to the anti induction device and so arranged as to be responsive
to telephonic or induced current signal but neutral to voltaic or battery currents.
I may so apply condensers to the telephone line as to enable me to utilize as a
return wire a neighbouring parallel telegraph line without anti induction devices
being attached to the latter, and without grounding. This I accomplish by con-
necting the return wire to the Telephone line through suitable condensers or their
equivalent or through a high artificial resistance the telephones being included in
the circuit on either side of the condenser Any electro magnet at an intermediate
station on a telegraphic line being bridged by a condenser. Any manipulator or
key at an intermediate station on a telegraph line must be bridged by shunting the
manipulator and the adjacent receiver or other electro magnet by the anti induction
device hereinbefore mentioned.
In figure 1 B, B, B, B, is a telegraph line m B the line battery K the key and
R the receiver or relay, C is a condenser of large capacity forming a bridge or
shunt to the key and relay, or to the key and one coil of the relay. C³ is a con-
denser also of large capacity forming a shunt or bridge to the key K¹ and to one or
both coils of the receiver or relay R¹. These condensers so connected constitute
the "anti induction device" previously referred to. and are telephone branch
lines connected with the line between two Telegraph stations or two sets of
Morse instruments: E M and E M' are two electro magnets for blocking the
telephone current on the ground side of the line. Tand T are telephones in the

page_text: .
telephone branch lines and C³ and C are condensers of small capacity (for example
about a Microfarad) also in said telephone branch lines. The anti induction
device prevents the manipulation of the keys K and K¹ from causing any dis-
turbance in the telephones T and T while the electro magnets EM and E M¹
prevent short circuiting of the telephone circuit through the large condensers to
ground. These electro magnets have a high coefficient of self induction but need
not necessarily have high resistance. From 100 to 200 Ohms is sufficient.
Communication is established between the telephones T and T¹ by means of the
small condensers C3 and C³ and the intervening telegraph line B B and as described
in the specification to Letters Patent N° 1477, 1879 herein before referred to. In
Figure 2 is represented a modification of the arrangement of telephone circuit as
described in Figure 1 namely the telephone circuit including the telephone T
instead of being grounded forms a bridge or shunt to the electro magnet E M.
The connections of the anti induction device are the same as in Figure 1. In
Figure 3 the telephone T is inserted in the telegraph circuit and the blocking
electro magnet is omitted. In Figure 4 the arrangement is the same as in Figure 3
with the exception that the anti induction device forms a bridge or shunt to a
battery microphone B M and a battery telephone B, T, instead of to a key and
relay. T and T¹ represent the ordinary induced current telephones and telephonic
apparatus. The shunting of the battery telephone or direct working telephone
systein by the anti induction device suppresses induction from said direct working
telephones from which two objects are gained namely firstly the induced current
system may be used as a duplex on the same wire without interference and
secondly two parallel wires may be used simultaneously without interference both
being equipped with the battery telephones and the anti induction device.
In Figure 5 A is a telephone line and B a parallel telegraph line equipped with
the anti induction device as already described namely the key and one or both
coils of the receiver or other electro magnet is bridged or shunted by a condenser
of large capacity. By this arrangement the telegraph induction in line B, is
suppressed so that the telephonic apparatus at T and T¹ may be used without
disturbance from telegraph induction. By this arrangement telegraph and telephone
wires may be carried by the same cable or the same supports.
In figure 6 A and B are two parallel telegraph wires Both are equipped with
the anti induction device as represented at C and C and both have self induction
electromagnets as shewn at E. M. and E. M¹ At D and D2 and at D¹ and at D³
the two telegraph wires are joined by bridge lines. In each of these bridge lines
is inserted a small condenser (C³ C³) and a telephone (I and I¹) or telephonic
apparatus. By this arrangement an artificial metallic circuit. is established
between the telephonic apparatus inserted in the two branch lines. One of these
lines is used for the signalling apparatus as represented at G and G in line B.
In Figure 7 A and B are two parallel telegraph wires equipped with the anti
induction device and blocking electro magnets as represented in Figure 6 While
and are branch lines extending to a telephone exchange office in the form of a
loop, and 13, 14 represent a subscribers direct and return wire, By this arrangement
of circuits the subscribers of a telephone exchange system may be looped in to the
branch line connecting D and D' of the telegraph wires A and B and by a similar
arrangement at the other end of the line the two parallel telegraph wires may be
used as an artificial metallic circuit for connecting the subscribers of a distant
telephone exchange.
Figure 8 represents a convenient arrangement of the circuits for "calling up" or
signalling on an artificial telephone circuit. B is a telegraph line equipped with
the anti induction device and with diverting electromagnets, and is a branch line
for the telephonic apparatus, 15 is a ground wire for the electric generator G and
16 is a separate ground wire for the telephonic apparatus. Sw is a switch,
preferably automatic, for alternately shunting the signalling and the speaking
apparatus C is a large condenser in the branch line and C* is a small condenser
in the telephone branch or ground line.

page_text: The action of this arrangement is as follows. In transmitting or receiving a
signal, the strong signalling current passes from or to the line through the large
condenser C and the wire to ground direct, whereas in speaking the induced
current passes to ground indirectly through the small condenser C. The large.
condenser admits. of strong signalling currents being used and the small condenser
protects the telephone from telegraph induction. The capacity of the small
condenser is insufficient for strong signalling currents and the capacity of the
large condenser is too great to be suitable for the telephone circuit. By placing
the large condenser in the branch line as represented it may be installed at
the telegraph office which would be considered an advantage as the danger of
grounding the line would be reduced to a minimum otherwise the large condenser'
might be inserted in the ground wire of the electric signal as in in Figure 9.
Figure 9 is a modification of figure 8 The branch line instead of going to
ground simply forms a bridge or shunt to the blocking electromagnet E. M. The
switch S. w, shunts either the generator and large condenser or the telephonic
apparatus and small condenser at pleasure.
In figure 10. B is a telegraph line equipped with the anti induction device
E M is the electromagnetic deflector and G an electro generator arranged as a
bridge or shunt to said electromagnet. This arrangement may be used in some
cases instead of the arrangement represented in Figure 9. The telephonic apparatus
is connected with the generator by means of switches in the usual management of
microphone and receiving telephone.
In figure 11 is shown a modification of the arrangement represented in figure 10.
G is an electro generator forming a shunt to the electromagnet E. M in the
telegraph line P. R is the polarized receiver detached from the generator and
inserted in the anti induction circuit which latter forms a bridge or shunt to the
key and relay of the telegraph system. In some cases it is an advantage to have
the magneto receiver in this position.
Figure 12 and figure 12ª represents a special receiving signal, B. B, is a telegraph
line with each set of morse instruments bridged by condensers or their equivalent.
DR is the special receiving signal which may be called a duplex receiver.
It is an electromagnet with two coils the one with a high coefficient and (long
coil) the other with a low coefficient of self induction (short coil) but the two:
adjusted upon the electromagnet so as to render said electromagnet neutral to the
primary electrical currents of the line. One of these coils, preferably the one with
a high coefficient of self induction (long coil) is bridged or shunted by a condenser
of high capacity. This condenser may be used to bridge or shunt a key and relay
in addition to bridging said coil and as represented in the figures. When thus
arranged a strong induced current superimposed upon the line will act upon the
short coil without acting upon the other and this action may be utelized for
signalling, either by the direct or by the indirect movements of the armature.
In Figure 13. B B is a telegraph line and E M an electromagnet in the main
line P. is a push button switch for switching the large condenser C from d to f
When at rest an induced current signal coming from the line is blocked by the two
electromagnets EM and R. and is diverted from the line at the point D and passes
into the branch line through l. d P and C to the duplex receiver D. R. and thence
to ground through 1. On transmitting a signal the current passes from the
generator G, through the switch and d and l to line direct. In speaking however
the push button is pressed so as to move the switch to the point of this connects the
large condenser with the line at F and indirectly with the line at D. through the
telephone T and the small condenser 0 In this arrangement two points are
gained namely first two electromagnets are used to deflect the induced current
from the line, secondly the signalling apparatus is in the best position for trans-
mitting or receiving a signal.
Figure 14 represents a method of utilizing a telegraph wire as a return wire to
form a telephone metallic circuit in cases where a telephone wire is conducted
parallel to a telegraph wire. A is the telephone wire and B the parallel telegraph

page_text: "
wire. Sw, is a switch for removing the telephone ground wire and connecting
the telegraph wire through the branch lines and . In one or both of these
branch lines a condenser or artificial resistance is inserted. By combining the two'
wires in the form of a metallic. circuit the use of the anti induction apparatus
becomes unnecessary and the induction from parallel wires is largely eliminated.
Figure 15 represents the arrangement of the anti induction device on lines
where the open circuit system is used. B, is the telegraph line M B the battery at
one end, K, the key and E M and EM two electromagnets in the main line, one of
which is the receiver, C is a condenser of large capacity connected with the line at
the point F between the two electromagnets on one side of said condenser and
with the battery on the other. The electromagnet between the key and the
point F prevents the rapid discharge of the condenser when the key is closed.
In figure 16 is represented a method of using the two coils of the receiver or
relay in connection with the anti induction device B is a telegraph line and R the
receiver, or relay a and b representing the two coils thereof. The a coil is bridged
or shunted by the large condenser C, while the b coil is bridged or shunted by the
telephone circuit including the small condenser C².
In figure 17 and figure 10 is represented the method of treating way telegraph
stations when the line is used for telephonic purposes B. B. is a telegraph line
equipped at each end with telephonic apparatus and the anti induction device
W. S. is a way telegraph station. This way station is simply equipped with the
anti induction device as represented..
It is to be understood however that way telegraph stations may be equipped
with telephonic apparatus the same as terminal stations. It is also to be under-
stood that any portion of a telegraph line may be utilized for telephonic purposes...
In figure 18 is represented what I call a telephonic telegraph repeater A and B
are two telegraph lines radiating from the Head Office H and each equipped with
telephonic apparatus and the anti induction device as represented in the figure
C7 is a condenser or other inductor connecting the two lines at the points D and D
beyond the receiver and diverting electromagnet.
By this arrangement telephonic communication may be established between the
stations at T and T¹ The condenser or inductor C translates or repeats from line A.
to line B.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
First. The combination of two parallel circuits with telephonic instruments in
connection with each and an "anti induction" device so arranged and combined
together as to constitute in effect three sets of simultaneous and independent
telephones on two parallel lines substantially as and for the purposes hereinbefore
described Also the arrangement of telegraph instruments in connection therewith
substantially as and for the purposes herein before described.
Second. The combination of a telephone circuit or wire and a telegraph circuit
or wire parallel with each other and with an "anti induction " device substantially
as herein described and for the purpose set forth.
an
"
Third. In telephone and telegraph lines the combination of "anti induction
device arranged as a bridge or shunt substantially as bereinbefore described and the
arrangements, thereof hereinbefore explained and illustrated in the accompanying
drawings.
Fourth. The combination of condensers or their equivalent and a telephone line
and a neighbouring or parallel telegraph line in the manner herein before described
so as to enable the neighbouring parallel telegraph line to be utilized as a return
wire substantially as herein before described.
Fifth. The combination with a single telegraph line an anti induction device and
telegraphic instruments bridged or shunted with condensers of large capacity and

page_text: telephonic instruments inserted wholly or in part in the main line or attached
wholly or in part as a shunt or bridge substantially as and for the purposes
herein before described.
Sixth. The combination with two parallel telegraph lines of anti induction
devices and condensers the two lines being connected at each end by a bridge
containing a telephone and condenser or its equivalent the signal working through
the large condenser of the anti induction device in one of the telegraph wires all
substantially as and for the purposes hereinbefore described.
Seventh. In arrangements of the kind referred to in the preceding claiming
clauses a call bell or signal connected to and forming a bridge or shunt to an
electromagnet inserted in the line between said line and an anti induction device
substantially as and for the purposes herein before described.
Eighth. The modification of the subject matter of the preceding claiming clause
wherein the receiving bell or signal is inserted with the condensers in the shunt or
bridge part of the anti induction device through which device the calling is affected
all substantially as and from the purposes herein before described.
Ninth. In combined telephone and telegraph lines a signalling circuit device
with a large and a small condenser so arranged that the small condenser may be
shunted from the circuit during signalling and the two condensers arranged in
series during the conversation substantially as and for the purpose hereinbefore
described.
Tenth. For uniting two separate telephone lines each duplexed with a telegraphic
apparatus the combination of a condenser or condensers or other inductors so that
the two lines constitute one for telephonic purposes and said inductors serve as
a translating device substantially as hereinbefore described.
Eleventh. In a telephonic circuit or main line the use of differentially wound
coils in a receiver one coil being connected to or bridged by a condenser or an anti
induction device and so arranged as to be responsive to telephonic or induced
current signals but neutral to voltaic or battery currents substantially as herein-
before described.