Improvements in the Means for Distributing Telephonic Currents to Theatrophones and other similar Apparatus.
Year: 1892

page_text: Date of Application, 24th June, 1892
Complete Specification Left, 1st Feb., 1893-Accepted, 4th Mar., 1893
PROVISIONAL SPECIFICATION.
Improvements in the Means for Distributing Telephonic Currents
to Theatrophones and other similar Apparatus.
We, BÉLIZAIRE MARINOVITCH and GÉZA SZARVADY both of 16 Rue Drouot,
Paris, France, Electrical Engineers, do hereby declare the nature of this invention
to be as follows:-
:-
In ordinary systems for effecting telephonic communications every apparatus is
connected by a separate wire with the central office or exchange. Different
arrangements have been proposed to allow one wire to serve for several apparatus,
but in this case the different places connected by the same wire cannot communicate
simultaneously with the central office or exchange and through it with other
telephones.
The present invention does not relate to ordinary telephonic apparatus for
carrying on conversations between different places but to the apparatus known as
theatrophones and other similar apparatus which have for object to give telephonic
auditions, that is to say to enable concerts, theatrical performances, speeches, and
the like to be heard at a distance.
The object of our invention is to enable a great number of these apparatus to be
served by a single line, the said apparatus being so arranged relatively to each
other that each of them can act at any moment independently of the others either
alone or simultaneously with one or more others.
'We effect this object in one or other of the following ways:—
According, to one way the theatrophones are each fitted with a switch which
short-circuits the telephones when the apparatus is not in action. All the
theatrophones are placed in series. In order to put any particular apparatus into
action it is only necessary to move the switch so as to open the short circuit. (In
cases where the temporary use of the apparatus is to. be paid for the.switch may
be actuated by the insertion of a prescribed coin or token into a suitable machine
of the automatic" kind.) The concert, speech, or the like can at once be heard
in the telephones without the movement of the switch having become perceptible
at the other apparatus.
According to another way the theatrophones are provided with resistances (with
or without iron cores) and sometimes with condensers, these resistances and
condensers being such as may appropriately be substituted for the telephones by
means of a switch. This switch is so pivoted that it can as required put the line
in communication either with the telephones or with the resistances. The rubbing
or contact part of the switch is sufficiently long to prevent its leaving the telephone
contact before touching the resistance contact and vice-versa. Any temporary
interruption in the line is thus obviated. The theatrophones in this case also are
placed in series.
arc.
According to a third way the theatrophones are placed in derivation or multiple
The wires leading to the receivers are provided with interrupters by means
of which the receivers can be connected with the line or disconnected therefrom
at will.
According to another way we combine the ways above described by placing for
example several theatrophones in series in the saine derivation.
The invention is applicable to both single wire and double wire lines.
Dated this 24th day of June 1892
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Chartered Patent Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in the Means for Distributing Telephonic Currents
to Theatrophones and other similar Apparatus.
We BÉLIZAIRE MARINOVITCH and GÉZA SZARVADY, both of 16 Rue Drouot,
Paris, France, Electrical Engineers, 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:-
In ordinary systems for effecting telephonic communications every apparatus is
connected by a separate wire with the central office or exchange. Different
arrangements have been proposed to allow one wire to serve for several apparatus,
but in this case the different places connected by the same wire cannot com
municate simultaneously with the central office or exchange, and through it with
other telephones.
The present invention does not relate to ordinary telephonic apparatus for
carrying on conversations between different places, but to the apparatus known as
theatrophones and other similar apparatus which have for object to give telephonic
auditions, that is to say to enable concerts, theatrical performances, speeches and
the like to be heard at a distance.
The object of our invention is to enable a great number of these apparatus to be
served by a single line, the said apparatus being so arranged relatively to each
other that each of them can act at any moment independently of the others, either
alone or at the same time as one or more others.
We effect this object in one or other of the following ways:-
According to one way, which is illustrated in Figure 1 of the annexed drawings
the theatrophones are each fitted with a switch CD which short-circuits the
telephones when the apparatus is not in action. All the theatrophones are placed
in series. In order to put any particular apparatus into action it is only necessary
to move the switch CD so as to open the short circuit. (In cases where the
temporary use of the apparatus is to be paid for the switch may be actuated by the
insertion of a prescribed coin or token into a suitable machine of the "automatic i
kind.) As soon as the switch is moved the concert, speech or the like can be heard
in the telephone without the movement of the switch having become perceptible at
the other apparatus on the same line.
"7
The figure represents the complete installation of the line diagrammatically.
M M are microphones placed in a theatre on each side of the prompter's box O.
The battery of the microphone circuit is indicated at N and the primary of the
induction coil at P. The theatrophone line starts from the secondary S of the
induction coil and leads at XX to the central office A where it is connected to a
switch board. It leaves the central office at Y Y and passes successively through
a certain number of theatrophones. RR are telegraphic indicators showing which
theatre the theatrophones are connected with for the time being. They are worked
by means of a manipulator K within reach of the attendant. B is the battery the
current from which moves the indicators RR. R is a repeater in the central
office to enable the attendant to check the signals sent by him. T T are the
theatrophonic or telephonic receivers and E E earth connections.
According to another way which is represented in Figure 2 the theatrophones
are provided with resistances which may appropriately be substituted for the
telephones by means of a switch A' B₁ C. This switch is pivotted on the axis O'
so that it can as required put the line O Z in communication either with the
telephones by DV or with the resistances by F V. The rubbing or contact
part BC of the switch is sufficiently long to prevent its leaving the telephone
contact D before touching the resistance contact F and vice versa. Any temporary
interruption in the line is thus obviated. The theatrophones in this case are also
placed in series. In some cases it is advantageous to add condensers to the

page_text: resistances r, in which case the switch is moved so that the rubbing part B¹C comes
in contact with the contact E.
According to a third way which is represented in Figure 3, the theatrophones
are placed in derivation or multiple arc. The wires V Z leading to the receivers
are provided with interrupters CD by means of which the receivers can be connected
with the line or disconnected therefrom at will.
According to another way we combine the ways above described by placing for
example several theatrophones in series in the same derivation. This will be fully
understood on reference to Figure 4.
The invention is applicable to both single wire and double wire lines.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
olaim is:-
The several means hereinbefore described whereby a number of theatrophones
or other similar apparatus can be served by a single line and in such manner that
each of the apparatus can act independently of the others, as set forth.
Dated this 1st day of February 1893.
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Chartered Patent Agent.