Improvements in and connected with Telephone Systems.
Year: 1890

page_text: Date of Application, 15th Jan., 1890
Complete Specification Left, 13th Oct., 1890-Accepted, 13th Dec., 1890
PROVISIONAL SPECIFICATION.
Improvements in and connected with Telephone Systems.
We, WILHELM OESTERREICH of No. 3 York Strasse Electrician and WERNER
GENEST of No. 14 Neuenburgerstrasse Manufacturer, both of Berlin in the Empire
of Germany do hereby declare the nature of this invention to be as follows:-
In telephone systems where several speaking stations are to be put in communica-
tion with each other a central switchboard is generally used at a central station having
lines leading to the several speaking stations, and the connection is made through
them between any two stations after the connection with the central station has been
severed. This system or mode of working requires the personal aid of a person at
the central station and causes more or less delay.
By means of the present invention the speaking stations are enabled to communicate
severally with each other without any intermediary person.
Each speaking station has its telephone apparatus as usual, and is provided with a
switchboard having plug holes which may be of ordinary form and in number equal
to that of the stations which are to communicate. Lines lead from each plug hole to
the corresponding ones at the other stations. Each apparatus has a plug which by a
wire cord is connected to its telephone apparatus or station. When at rest the plug
at No. 1 station is in the plug hole for No. 1 line, that at No. 2 station in the plug
hole for No. 2 line, and so on. If for instance No. 1 wishes to talk with No. 2 he
puts the plug in the No. 2 hole, while No. 2 leaves the plug in its No. 2 hole. When
done talking No. 1 replaces his plug in the No. 1 hole. Obviously several or all
stations may simultaneously converse with each other, if the plugs are connected to
one and the same line.
In another arrangement the switchboard at each speaking station has only as many
plug holes as there are stations it can call up, for instance No. 1 station has only plug
holes Nos. 2, 3, 4 and so on while line No. 1 is fixedly connected with telephone apparatus
No. 1 by a branch. Each station has besides, as in the previous example a plug with
wire cord connected to the telephone; such plug is not inserted when the apparatus is
at rest. To call up a station the plug is inserted in the corresponding plug hole.
When done talking the plug at the calling station is removed from the hole. This
switch arrangement compared with the previously described one has the advantage
that the speaking stations always are in fixed connection each with its own line and
hence cannot be cut ont.
A suitable form of plug applicable in the switch arrangements described and
serving also to supersede the call button, is as follows. It is made in the form of a
stem with conical plug head, a vulcanite tube pushed upon the stem and having
a collar flush with the plug head, and a metal tube fitted on the vulcanite tube and
flush with the collar and plug head. The metal stem (and plug head) has a wire cord
connected to the call battery; and the metal tube has a wire cord connected to the
binding screw of the apparatus. The length of the metal tube of the plug is such as
to be equal that of the plug hole in the switchboard. When inserting the plug the
point or head connected to the call battery first touches the sides of the plug hole and
sends a calling up current into the line called, but when the plug has been inserted so
far that the metallic pointer end has gone through the hole the vulcanite collar pro-
duces insulation while the metal tube on the plug keeps up connection with the plug
hole. The depression of the call button is thus saved, and at the second speaking
station a control can take place that the corresponding station has withdrawn the plug
again.
In another arrangement of system a crank switch is used, which is particularly
applicable with a small number of lines. The latter are all permanently connected

page_text: with the contacts on the cranks, the axes of the cranks being connected to the binding
screws of the telephones. The cranks may then, analogous to the first described
arrangement in the position of rest, be put in its proper contact or also be permanently
connected with the said contact in analogy with the secondly described arrangement.
Dated this 15th day of January 1890.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.
COMPLETE SPECIFICATION.
Improvements in and connected with Telephone Systems.
We, WILHELM OESTERREICH of No. 3 Yorkstrasse Electrician and WERNER GENEST
of No. 14ª Neuenburgerstrasse Manufacturer both of Berlin in the Empire of Germany
do hereby declare the nature of the said invention and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement:
In telephone systems where several speaking stations are to be put in communication
with each other a central switchboard is generally used at a central station having lines
leading to the several speaking stations, and the connection is made by the central
station between any two stations after the central station has been called. This system
or mode of working requires the personal aid of a person at the central station and
causes more or less delay.
By means of the present invention the speaking stations are enabled to communi-
cate severally with each other without any intermediary person.
Figure 1 shows the switch arrangement for four stations which are connected with
one another by means of a switch (line selector).
Each speaking station has its telephone apparatus T' T2 T3 T4 as usual and is provided
with a switchboard U₁ U2 U3 U having plug holes 1, 2, 3, 4 which may be of ordinary
form and in number equal to that of the stations which are to communicate. Lines
LI² L³ L lead from each plug hole to the corresponding ones at the other stations.
Each apparatus has a plug S1 S2 S3 S4 which by a wire cord is connected to the terminal
of its telephone apparatus or station T1 T2 T3 T4. When at rest the plug at No. 1 station
is in the plug hole for No. 1 line, that at No. 2 station in the plug hole for No. 2.line,
and so on.
If for instance No. 1 wishes to talk with No. 2 he puts the plug in the
No. 2 hole while No. 2 who is called up leaves the plug in its No. 2 hole. When done
talking No. 1 replaces his plug in the No. 1 hole. Obviously several or all stations
may simultaneously converse with each other, if the plugs are connected to one and
the same line.
In another arrangement shewn in Figure 2 the switchboard at each speaking
station has only as many plug holes as there are stations it can call up for instance
No. 1 station has only plug holes No. 2, 3, 4 and so on while line I is fixedly con-
nected with telephone apparatus T by a branch 1. Each station has besides as in the
previous example a plug S¹ (S² S³ S₁) with wire cord connected to the telephone, such
plug is not inserted when the apparatus is at rest. To call up a station the plug is as
with Figure 1 inserted in the corresponding plug hole. When done talking the
operation at the calling station is only altered so far that the plug at the calling station
is removed from the hole. This switch arrangement compared with the previously
described one has the advantage that the speaking stations always are in fixed con-
nection each with its own line and hence cannot be cut out.
A suitable form of plug applicable in the switch arrangements described with refer-
ence to Figures 1 and 2 and serving also to supersede the call button is as follows and
as shown in Figure 3. It is made in the form of a stem with conical plug head, a
vulcanite tube pushed upon the stem and having a collar flush with the plug head,
and a metal tube h fitted on the vulcanite tube and flush with the collar and plug head.
The metal stem k (and plug head) has a wire cord sk connected to the call battery B
and the metal tube has a wire cord sh connected to the binding screw of the

page_text: apparatus. The length of the metal tube of the plug is such as to be equal that of
the plug hole in the switchboard U¹ U² U³ Uª. When inserting the plug s the point
or head connected to the call battery B first touches the sides of the plug
hole and sends a calling up current into the line called, but when the plug has been
inserted so far that the metallic pointed eud has gone through the hole the vulcanite
collar produces insulation while the metal tube on the plug keeps up connection
with the plug hole. The depression of the call button is thus saved and at the second
speaking station a control can take place that the corresponding station has withdrawn
the plug again.
In another arrangement of system shewn in Figure 4 a lever switch is used which
is particularly applicable with a small number of lines. The latter are all permanently
connected with the contacts 1, 2, 3, 4 on the cranks U₁ U2 U³ U the axes of the cranks
being connected to the binding screws of the telephones. The cranks k¹ k² k³ k¹ may
then analogous to the first described arrangement Figure 1 in the position of rest, be
put on its proper contact or also be permanently connected with the said contact in
analogy with the secondary described arrangement.
In conjunction with the above described switches we may apply a switch arrange-
ment to the telephone whereby it becomes possible on the one hand to call up a station
and at the same time to connect with it by merely inserting a plug, and on the other
hand at the end of the conversation to cause the caller to draw the plug out. Such an
arrangement is shown in Figure 5 in connection with the switch arrangement of
Figure 2. The plain plug s¹ (s², s³, s¹) is through the working contact key a of the
self-acting switch connected with the telephone T₁ (T2, T3, T4), and the second terminal
screw of the telephone is at 61 (62, 63, 64) connected to the common battery A. The
call W, (W2 W3 W4) is in the usual manner on the one hand connected with the
contact of rest r for the automatic switch and on the other hand at e¹ (e², e³, e¹), with
the common return line or earth E.
Supposing the telephone T, wishes to talk with the telephone T" the plug s¹ is put
into the hole 2. The calling current from the battery B then passes via b¹¹ a s², in
the called up line L² 12 and vir through the call W2 to the common return line or
to earth. The call W2 is sounded and a loud noise is heard in the unhooked telephone,
whereby the caller is informed that the call at T is sounding. When now the
telephone T2 has been taken off its hook the noise ceases and the two telephones are
connected so as to be able to talk with each other while using the common line B. If
the telephone T2 does not answer at once it may be presumed that there is no one
present there, and the caller can then put his telephone on the hook again, so that the
call at T ceases to sound. If the telephone T2 does answer both parties will when
done talking hang up their telephone again. If the caller forgets to pull the plug s¹
out before he hangs up his telephone T' then the call W2 will continue to sound as
soon as the telephone T2 has been hung up. But this will as already stated produce a
loud noise in the telephone T whereby the person at that place will be caused to draw
out the plugs and put the switch U in the normal position.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed we declare that what we claim is :
First. In telephone installations where several speaking stations are to communi-
cate without an intermediary the application of switches which are connected with
each other by as many lines which end in independent contacts as there are stations
in such manner that the telephone which in position of rest is kept connected with
its line can by means of plugs or lever switches be connected directly with any one
of the other lines substantially as set forth.
Second. In telephone installations where several speaking stations are to communi-
cate without an intermediary, the application of switches which are connected with
each other by as many lines as there are stations, which lines are in constant connection
each with its telephone in such manner that each telephone can by means of plugs
or lever switches be connected directly with any one of the other lines substantially
as set forth.

page_text: Third. In combination with the switch firstly or secondly claimed a plug consisting
of two parts insulated from each other and cach connected to a conductor cord in such
manner that the connecting plug can also at the same time be used for calling,
substantially as set forth.
Fourth. In telephone installations where several speaking stations can communicate
without an intermediary, a telephone switch, in which the plug or lever serving for
connecting to the other lines through the working contact key of the selfacting switch
is connected with the telephone, and the second terminal of the latter is connected
with the common battery, in such manner that the call appliance on the called up
station (being on the one hand connected with the contact key of rest of the self-
acting switch and on the other hand connected with the common return line on earth)
shall sound continuously when the caller after the talking is over forgets to put the
apparatus into the normal position, substantially as set forth.
n: 1911 Laye of Octalian 1800
JENSON & SON,
77, Chancery Lane, London, W.C., Patent Agents.