Improvements in Apparatus for Registering the Number or Duration of Telephonic Conversations.
Year: 1894

page_text: Date of Application, 16th Aug., 1894
Complete Specification Left, 13th May, 1895-Accepted, 22nd June, 1895
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Registering the Number or Duration
of Telephonic Conversations.
I, AUGUST MÜNCH, of Kurfürstendamm 17 Charlottenburg, in the German
Empire, Post Office Superintendent, do hereby declare the nature of this invention
to be as follows:-
This invention relates to apparatus for registering the number of times
telephonic apparatus is used for conversation and if desired the duration of
such conversations.
The employment of counting apparatus for effecting the registration of the
number or the duration of the conversations carried on by telephone subscribers is
attended with very great difficulties in practice, and partly by reason of the
peculiarity of the mode of action and the means used to bring about that action.
Moreover, both for the registration of the number and of the duration of con-
versations it is essential that any apparatus which is to be regarded as satisfactory
should be easily and cheaply applicable to the means and methods of working and
to the arrangements already in use.
The apparatus constructed according to this invention records automatically and
reliably the number or the duration of the conversations carried on, the operation
of the registering mechanism being effected by electricity, by means of single
impulsions of the current which excite an electro-magnet which serves to move the
registering mechanism. This electro-magnet is so connected with the switch
mechanism of the central exchange that when the plug is used at the central
exchange for the purpose of connecting or separating two subscribers' instruments,
circuit-closing devices are automatically brought together or separated, for instance,
by the action of the plug upon a plate, the circuit of the electro-magnet being by
this means either closed or opened, so that it acts upon the registering mechanism.
This arrangement is suitable for single or multiple switch-boards alike, of
whatever system, and possesses the advantage that the registering apparatus may
be set up as required at the central exchange, and allows the usual switches to
remain unaltered as regards the main details of their arrangements.
The apparatus
under description has also the special advantage that it does not require a special
manipulation of the officer for operating the registering mechanism. From this it
necessarily follows that, given a suitable construction of the registering mechanism,
the record of the connections made is an absolutely accurate one.
A suitable arrangement for carrying out my invention as applied to a multiple
switch-board worked with contact plugs is as follows:-To the earth connection
of a subscriber's circuit and which also serves as the earth connection of a local
battery circuit which includes the electro-magnets of the registering mechanism,
are arranged two circuit closing plates, which when in their normal position do not
touch. One of these plates has on its lower surface a projection which when the
switch-board plug is inserted or withdrawn causes the said plate to be moved into
momentary contact with the other plate whereby the electric circuit through the
electro-magnet of the registering mechanism is closed, the arinature of the said
magnet being thereby attracted, and by means of a pawl caused to operate a switch
wheel carried by an axle furnished with a worm. This worm engages with two
numbered discs which are able to rotate independently of each other, and one of
which has as in ordinary Krafft's revolution counter, 100 teeth and the other 101 teeth.
го

page_text: In connection with these discs are two pointers one of which stands constantly at
zero whilst the other turns with the second disc, the extent to which the latter has
turned as compared with the first disc being thereby indicated. The switch wheel
has advantageously 20 teeth, so that the armature must be operated 20 times to
effect one complete rotation of the said switch wheel. The closures of the circuit
are required for the registration of a conversation, in correspondence with the
working of the switch-board. A small numbered disc allows of checking the
connections made.
The mode of action of the apparatus is as follows:-
When a call is received from a subscriber, the attendant at the central station
draws the corresponding plug out of the earth connection, to see whether the desired
circuit be free. As the plug is withdrawn, the two contact plates are pressed into
contact with each other, so that the armature of the electro-magnet is attracted and
the switch wheel is turned to the extent of one tooth and the worm axle through
one-twentieth of a revolution; the small numbered disc will thus be moved half
the distance it is to be moved for a conversation. If the attendant finds the
desired circuit free, he will put the plug in the corresponding aperture of the switch
board and when the conversation is concluded, he will replace the plug in the earth
connection whereupon the armature will be again attracted, and move the worm
axle another twentieth of a revolution, the two partial revolutions moving the
registering disc sufficiently to make the desired record.
If the attendant finds the desired circuit engaged (as will frequently happen in
practice) he then places the plug, not in the earth connection again, but in an
independent aperture which may be either a dummy or provided with a contact
plate. The condition of the circuit may then be investigated by the attendant
from time to time, and when it is finally found to be disengaged, the connection is
made. When the conversation is concluded the plug is replaced in the earth
connection, and the registration by the counting mechanism is completed.
The attraction of the armature is more or less forcible according to the strength
of the current in the local circuit, so that it is necessary to provide an arrangement
by means of which the worm axle is prevented from turning through more than
one-twentieth of a revolution for a single movement of the armature.
For this
purpose a crown wheel with say twenty teeth is placed upon the worm axle and in
the intervals between these teeth a catch on the pawl engages at the moment when
the switch wheel has turned to the extent of exactly one tooth.
In order to effect the disengagement of the worm from the indicating discs when
it is desired to bring these to the zero point, these discs are carried by a bent arm
which rotates upon a pin, this arm being capable of being clamped by means of a
screw or other suitable means.
If it be desired to record not the number but the time or duration of the
conversations, a clock train is interposed in the local circuit by means of which the
time at which the circuit is opened and closed is exactly indicated, and the circuit
closing plates are further so arranged that they come into contact when the plug is
removed.
This clock train sets in rotation at a regular rate a disc having a number o
circuit closing pieces each of which comes into contact with a spring as the disc
rotates. If the disc makes a complete revolution in one minute, then at every ten
seconds the current passes through the local circuit, as long as the contact plates
are touching each other as in the case when the plug is removed from the earth
connection to be inserted into another circuit. As long therefore as the conversa-
tion is proceeding the armature is attracted every ten seconds, and at each
attraction it causes the registering mechanism to rotate one tooth. When at the
conclusion of the conversation the plug is again placed in the earth connection, its
end, which acts upon the projection hereinbefore referred to pushes one of the
circuit closing plates, so that the circuit is interrupted, and the electro-magnet is
no longer excited. Thus instead of the number of the conversations their duration
is registered. The circuit closing disc with its connected parts, may serve for any

page_text: desired number of subscribers, the registering electro-magnets of each of which is
in connection with the said spring.
Dated the 16th day of August 1894.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
Improvements in Apparatus for Registering the Number or Duration
of Telephonic Conversations.
I, AUGUST MÜNCH, of Kurfürstendamm 17 Charlottenburg, in the German
Empire, Post Office Superintendent, 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 apparatus for registering the number of times
telephonic apparatus is used for conversation and, if desired, the duration of such
conversations.
The employment of counting apparatus for effecting the registration of the
number or the duration of the conversations carried on by telephone subscribers
is attended with very great difficulties in practice, partly by reason of the
peculiarity of the mode of action and the means used to bring about that action.
Moreover, both for the registration of the number and of the duration of con-
versations, it is essential that any apparatus which is to be regarded as satisfactory
should be easily and cheaply applicable to the means and methods of working and
to the arrangements already in use.
The apparatus constructed according to this invention records automatically and
reliably the number or the duration of the conversations carried on, the operation
of the registering mechanism being effected by electricity, by means of single
impulses of the current which excite an electro-magnet which serves to move the
registering mechanism. This electro-magnet is so connected with the commutator
or switch device of the central exchange that when the plug is used at the central
exchange for the purpose of connecting or separating two subscribers' instruments,
circuit-closing devices are automatically brought together or separated, for
instance, by the action of the plug upon a plate, the circuit of the electro-magnet
being by this means either closed or opened so that it acts upon the registering
mechanism.
This arrangement is suitable for single or multiple commutators or switch-
boards alike, of whatever system, and possesses the advantage that the registering
apparatus may be set up as required at the central exchange, and allows the usual
switches to remain unaltered as regards the main details of their arrangements.
The apparatus under description has also the special advantage that it does not
require a special manipulation of the attendant for operating the registering
mechanism. From this it necessarily follows that, given a suitable construction
of the registering mechanism, the record of the connections made is an absolutely
accurate one.
To enable my invention to be fully understood I will describe how it can be
carried into practice by reference to the accompanying drawing, in which :-
Figure 1 is a longitudinal section of a suitable arrangement of apparatus for
registering the number of telephonic conversations according to my invention as
used in connection with a multiple switch-board worked with contact-plugs :
Figure 2 is a front elevation of the registering mechanism:
Figure 3 is an elevation of the switch-board contact-plug; and,
Figure 4 is a view shewing the apparatus adapted to record the time or duration
of telephonic conversations.

page_text: I will first describe my invention by reference to Figures 1 to 3.
To the earth connection a of a subscriber's circuit, and which also serves as the
earth connection of a local battery circuit g which includes the electro-magnet h
of the registering mechanism, are arranged two circuit closing plates b and c which,
when in their normal position, do not touch. One of these plates c has on its lower
surface a boss or projection d which, when the switch-board plug e, Figure 3, is
inserted or withdrawn, causes the said plate c to be moved into momentary contact
with the other plate b, whereby the electric circuit g from the local battery f
through the electro-magnet h of the registering mechanism is closed, the armature i
of the said magnet being thereby attracted and by means of a pawl k caused to
operate a switch wheel carried by an axle n furnished with a worm m. This
worm engages with two numbered discs P and which are able to rotate inde-
pendently of each other, and one of which has, as in an ordinary Krafft's revolution
counter, 100 teeth and the other 101 teeth. In connection with these discs are
two pointers one of which stands constantly at zero whilst the other & turns with
the disc the extent to which the latter has turned as compared with the disc p
being thereby indicated. The switch wheel I has advantageously 20 teeth so that
the armature must be operated 20 times to effect one complete rotation of the said
switch wheel. The circuit must be closed at will for the registration of each
conversation in accordance with the working of the switch-board. A small
numbered disc t allows of recording the unit number of conversations that have
taken place.
The mode of action of the apparatus is as follows:—
If the
When a call is received from a subscriber, the attendant at the central station
draws the corresponding plug out of the earth connection a to see whether the
desired circuit be free. As the plug is withdrawn, the two contact plates b and c
are pressed into contact with each other so that the armature i of the electro-
magnet is attracted and the switch wheel is turned to the extent of one tooth and
the worm axle n through one-twentieth of a revolution; the small numbered disc t
will thus be moved half the distance it is to be moved for a conversation.
attendant finds the desired circuit free, he will put the plug e in the corresponding
aperture of the switch-board and when the conversation is concluded, he will
replace the plug in the earth connection a whereupon the armature i will be
again attracted, and move the worm axle n another twentieth of a revolution, the
two partial revolutions moving the registering disc sufficiently to make the desired
record.
If the attendant finds the desired circuit engaged (as will frequently happen in
practice) he then places the plug, not in the earth connection a again, but in an
independent aperture which may be either a dummy or provided with a contact
plate. The condition of the circuit may then be investigated by the attendant
from time to time, and when it is finally found to be disengaged, the connection is
made. When the conversation is concluded the plug is replaced in the earth
connection and the registration by the counting mechanism is completed.
For
The attraction of the armature is. more or less forcible according to the strength
of the current in the local circuit g so that it is necessary to provide an arrange-
ment by means of which the worm axle n is prevented from turning through more
than one-twentieth of a revolution for a single movement of the armature.
this purpose a crown wheel with, say, twenty teeth is placed upon the worm
axle n and in the spaces between these teeth a catch on the pawl k engages at
the moment when the switch wheel has turned to the extent of exactly
one tooth.
In order to effect the disengagement of the worm m from the indicating discs
and q when it is desired to bring these to the zero point, these discs are carried by
a bent arm which rotates upon a pin x, this arm being capable of being clamped
by means of a screw z or other suitable means.
If it be desired to record not the number but the time or duration of the
conversations, a clock train is, as illustrated in Figure 4, interposed in the local

page_text: circuit g by means of which the time at which the circuit is opened and closed is
exactly indicated, and the circuit closing plates b and c are further so arranged that
they come into contact when the plug is removed.
This clock train sets in rotation at a regular rate a disc A having a number of
circuit closing pieces C (six being shewn in the drawing) each of which comes into
contact with a spring B as the disc rotates. If the disc A makes a complete
revolution in one minute, then at every ten seconds the current passes through the
local circuit g as long as the contact plates b, c are touching each other as is the
case when the plug e is removed from the earth connection a to be inserted into
another circuit. As long therefore as the conversation is proceeding the armature
is attracted every ten seconds, and at each attraction it causes the registering
mechanism to rotate one tooth. When at the conclusion of the conversation the
plug e is again placed in the earth connection, its end, which acts upon the pro-
jection d, pushes the circuit-closing plate e so that the circuit is interrupted, and
the electro-magnet is no longer excited. Thus instead of the number of the
conversations their duration is registered. The circuit-closing disc with its
connected parts may serve for any desired number of subscribers, the registering
electro-magnets of each of which are in connection with the said spring B.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. An apparatus for registering the number or the duration of telephonic
conversations, characterized by a registering mechanism with a commutator or
switch device the pawl of which is subjected to the action of an electro-magnet
which when the plug is used by the attendant at the central exchange is excited
by one or more contacts being made without the necessity of special manipulation
on the part of the attendant, substantially as herein before described.
2. An apparatus for registering the number or duration of telephonic con-
versations, of the kind claimed in the first claiming clause, for use in connection
with multiple switch-boards constructed on the one wire system in which circuit-
closing plates are so connected to the earth connection that when the plug is
inserted into or removed from the latter the electro-magnet of the registering
mechanism is excited, substantially as hereinbefore described.
3. An apparatus for registering the duration of telephonic conversations, of the
kind claimed in the first claiming clause, in which circuit closing plates included
in the circuit of the registering mechanism are so arranged with reference to the
earth -connection that when the plug is removed from the latter they come into
contact with each other, so that by means of a clock train, interposed in the
circuit of the registering mechanism during the time of the conversation and which
closes and opens the circuit, the duration of the conversation is indicated by a
number of excitations of the electro-magnet of the registering mechanism by passages
of the current, substantially as hereinbefore described.
4. The improved apparatus for registering the number of telephonic con-
versations hereinbefore described with reference to Figures 1 and 2 of the
accompanying drawing.
5. The improved apparatus for registering the duration of telephonic con-
versations herein before described with reference to Figure 4 of the accompanying
drawing.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.