Improvements in Connections of Telephonic and Telegraphic Instruments to Conducting Lines.
Year: 1897

page_text: Date of Application, 15th Mar., 1897
Complete Specification Left, 14th Dec., 1897-Accepted, 14th May, 1898
PROVISIONAL SPECIFICATION.
Improvements in Connections of Telephonic and Telegraphic
Instruments to Conducting Lines.
I, LOUIS MAICHE, of 368, Rue St. Honore, Paris, France, Engineer, do hereby
declare the nature of this invention to be as follows:-
This invention relates to the connecting of telephonic and telegraphic instru-
ments to conducting lines in such a manner that several telephonic and telegraphic
messages can be simultaneously transmitted without interfering with one another.
Fig. 1 of the accompanying drawings shews diagrammatically connections for a
telephone and also for another telephone or telegraph to a double conducting line.
Fig. 2 shews a modification. Fig. 3 shews how seven sets of the connections may
be applied to four double conducting lines. Fig. 4 shews the connections for a
telephone and telegraph to a single line with earth return. Fig. 5 shews con-
nections for telephoning over two telegraph lines one of them forming a metal
return.
Referring first to Fig. 1 the two lines L¹ L³ are at each end connected as shewn
at X through two equal secondary coils s¹ and s² wound with a primary coil P which
is in circuit with a telephone transmitter T and local battery B.
The lines L' L2 are so connected to the secondary coils s¹s that the currents
induced in the lines by the telephone transmitter are always in opposite directions.
The telephone receiver R, as shewn at Z, is in circuit with a secondary coil 3 wound
with a primary coil 2 connecting the two lines L¹ L².
At a point intermediate to the coils s¹s a third line L³ is connected, this line
being employed for telephone or telegraph transmission. When either of the
telephone transmitters T is employed, the induced currents pass through the
primary coil P thus causing the receivers R to act. But should any current flow
by L3 it must flow in opposite directions through s¹ and s², and therefore in the same
direction along the lines L1 L2 so that it cannot influence the receivers R nor the
transmitters T. At each end a line L³ may be connected as shewn by Y, Fig. 2,
at a point intermediate to two equal primary coils pl p² which connect the
lines L L and are wound with the secondary of each telephone receiver R.
With connections thus arranged any current flowing in the same direction through
the coils p p actuates the telephone receivers R, whereas a current from L³ flows
in opposite directions through the coils p¹ p² and therefore is ineffective on the
receivers R. By combining several ordinary transmitters T and several of the
receiver arrangements marked Y in Fig. 2 with a number of double lines as shewn
in Fig. 3, a number of messages can be sent over these lines without interfering
with each other.
Thus referring to Fig. 3 the transmitter 1 works over the pair of lines L₁ in the
usual way, one of these lines serving as metal return. In like manner the
transmitter 2 works over the pair L₂, transmitter 4 over the pair L4 and trans-
mitter 5 over the pair L 5. Again the transmitter 3 works through the pair of

page_text: lines L3 and the two pairs L1 and L2, one of these pairs serving as metal return.
In like manner the transmitter 6 works through the pair of lines L 6 and through
the two pairs L4 L 5. Finally the transmitter 7 works through the pairs of
lines L7 and through the two pairs L3 and L6 and the four pairs L1 L2 L4
and L5, two of these pairs such as L4 and L5 serving as metal return.
Obviously this system may be duplicated, and reduplicated so that one trans-
mitter can be made to work over 8 pairs or 16 pairs of lines or other multiple of 4.
As shewn in Fig. 4 a telephone and a telegraph are connected to one line L
having earth return. In this case X and Z are the telephone arrangements so
marked in Fig. 1, K is the key, C the battery and D the receiver for telegraphing
in the connection of Z to earth there is an adjustable resistance F to balance that
of the line. As shewn in Fig. 5 two sets of the telegraphic connections shewn
in Fig. 4 and two lines L¹ L2 which may be both to one place or each to a different
place with earth return are combined with one telephone arrangement.
The transmitter T by its primary P induces currents in the secondaries s¹ s² both
in the same direction and therefore in opposite directions in the lines L¹ L². The
currents being in the same direction in 21 and 22 act on the secondaries 83 of the
receivers R. Currents from the telegraph dividing at pass in opposite
directions through s¹ and p¹ and therefore do not affect the telephonic receivers.
And in like manner the currents from the telegraph K2 are ineffective on the
receivers.
For the sake of clearness the primary and secondary coils have been shewn in
the form of many lines side by side.
It is to be understood however that they are wound in each case all on one bobbin.
In Figs. 3, 4 and 5 the arrangements are shewn at only one end of the conducting
lines.
It is to be understood however that they are symmetrically repeated at the other
end as shewn in Figs. 1 and 2.
Dated this 15th day of Manal 1907
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Connections of Telephonic and Telegraphic
Instruments to Conducting Lines.
I, LOUIS MAICHE, of 368, Rue St. Honore, Paris, France, Engineer, 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 the connecting of telephonic and telegraphic instru-
ments to conducting lines in such a manner that several telephonic and telegraphic
messages can be simultaneously transmitted without interfering with one other.
Figure 1 of the drawings accompanying my Provisional Specification shews
diagrammatically connections for a telephone and also for another telephone or
telegraph to a double conducting line. Figure 2 shews a modification. Figure 3
shews how seven sets of the connections may be applied to four double conducting
lines. Figure 4 shews the connections for a telephone and telegraph to a single
line with earth return. Figure 5 shews connections for telephoning over two
telegraph lines one of them forming a metal return.
Referring first to Figure 1. the two lines L' L² are at each end connected as shewn

page_text: at X through two equal secondary coils s¹ and s² wound with a primary coil P which
is in circuit with a telephone transmitter T and local battery B.
The lines L L are so connected to the secondary coils s¹s that the currents
induced in the lines by the telephone transmitter are always in opposite directions.
The telephone receiver R, as shewn at Z, is in circuit with a secondary coil s³
wound with a primary coil p of high resistance connecting the two lines LA L².
At the point intermediate to the coils s¹s a third line L³ is connected, this line
being employed for telephone or telegraph transmission. When either of the
telephone transmitters T is employed, the induced currents pass through the
primary coil p thus causing the receivers R to act. But should any current flow
by L it must flow in opposite directions through and 2, and therefore in the
same direction along the lines L' L' so that it cannot influence the receivers R nor
the transmitters T. At each end a line L³ may be connected as shewn
by Y, Figure 2, at a point intermediate to two equal primary coils which
connect the lines L¹ L2 and are wound with the secondary of each telephone
receiver R. With connections thus arranged any current flowing in the same
direction through the coils p₁ 22 actuates the telephone receivers R, whereas a
current from L3 flows in opposite directions through the coils p¹ p² and therefore is
ineffective on the receivers R. By combining several ordinary transmitters T and
several of the receiver arrangements marked Y in Figure 2 with a number of double
lines as shewn in Figure 3, a number of messages can be sent over these lines
without interfering with each other.
Thus referring to Figure 3 the transmitter 1 works over the pair of lines L 1 in
the usual way, one of these lines serving as metal return. In like manner the
transmitter 2 works over the pair L2, transmitter 4 over the pair L4 and trans-
mitter 5 over the pair L 5. Again the transmitter 3 works through the pair of
lines L3 and the two pairs L1 and L2, one of these pairs serving as metal return.
In like manner the transmitter 6 works through the pair of lines L6 and through
the two pairs L4 L 5. Finally the transmitter 7 works through the pairs of
lines L7 and through the two pairs L3 and L 6 and the four pairs L1 L2 L4
and L5, two of these pairs such as L4 and L 5 serving as metal return.
Obviously this system may be duplicated, and reduplicated so that one trans-
mitter can be made to work over 8 pairs or 16 pairs of lines or other multiple of 4.
As shewn in Figure 4 a telephone and a telegraph are connected to one line L
having earth return. In this case X and Z are the telephone arrangements so
marked in Figure 1, K is the key, C the battery and D) the receiver for telegraphing.
In the connection of P to earth there is an adjustable resistance F to balance that
of the line. As shewn in Figure 5 two sets of the telegraphic connections shewn
in Figure 4 and two lines L1 L2 which may be both to one place or each to a
different place with earth return are combined with one telephone arrangement.
The transmitter T by its primary P induces currents in the secondaries s¹s both in
the same direction and therefore in opposite directions in the lines L¹ L³. The
currents being in the same direction in p¹ and p2 act on the secondaries 53 of the
receivers R.
Currents from the telegraph K' dividing at pass in opposite directions
throughs and p¹ and therefore do not affect the telephonic receivers. And in
like manner the currents from the telegraph K2 are ineffective on the receivers.
The connections of p² and p² to earth may have suitable resistances as shewn at F
in Figure 4.
For the sake of clearness the primary and secondary coils have been shewn in
the form of many lines side by side.
It is to be understood however that they are wound in each case all on one
bobbin.
In Figures 3, 4 and 5 the arrangements are shewn at only one end of the conduct-
ing lines.
It is to be understood however that they are symmetrically repeated at the other
end as shewn in Figures 1 and 2.

page_text: Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is:
-
1. The connection of a telephone and an independently acting telephone or
telegraph to a double conducting line, the telephone transmitter having two equal
secondary coils connected to the lines in such a manner that the induced currents
traverse the lines in opposite directions, whilst the telephone receiver has a primary
coil of high resistance connected to both lines, the independent telephone or
telegraph being connected to the two secondary coils of the transmitter in such a
manner that equal currents from it traverse them in opposite directions, substan-
tially as and for the purpose set forth and illustrated in Figure 1.
2. The modified arrangement of the connection, the telephone transmitter having
a single secondary coil connected to both lines and the receiver having two equal
primary coils of high resistance connecting the two lines, the independent telephone
or telegraph being connected to the two primary coils of the receiver in such a
manner that equal currents from it traverse them in opposite directions, substan-
tially as described and illustrated in Figure 2.
3. The combination of several double conducting lines with sets of transmitters
and receivers arranged as in the preceding claim, substantially as described with
reference to Figure 2.
4. The combination of a single conducting line and earth return with a telephone
and telegraph substantially as described with reference to Figure 4.
5. The combination of a double conducting line and earth return with a telephone
and pair of telegraphs substantially as described with reference to Figure 5.
Dated this 14th day of December 1897.
ABEL & IMRAY,
Agents for the Applicant.