Improvements in Apparatus for Indicating or Recording Telephonic Connections:
Year: 1895

page_text: Date of Application, 13th Feb.; 1895-Accepted, 16th Mar.,
1895
COMPLETE SPECIFICATION.
Improvements in Apparatus for Indicating or Recording Telephonic
Connections:
We, FRIEDRICH WILHELM HEINRICH HEMPEL, of Waterlooufer 4, Engineer,
and ALFRED MAERKER, of Kochstrasse 9, Banker, both of Berlin, in the Empire
of Germany, 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 :-
The object of the present invention is to provide an arrangement by means of
which control or indication of use of the telephone by subscribers is obtained so
far as the subscriber is concerned, whilst the use of it on the part of the summoned
subscriber is not controlled. By this means the telephone management receives
indication of the amount of conversation led to by the summoning subscriber.
In Figure 1 of the drawing the apparatus is represented in front view in position
on a telephone with ringing crank.
Figure 2 shows the internal view of the telephone seen from behind, and
Figures 3 and 4 are details hereinafter referred to.
On the front wall of the telephone and near the ringing crank k there is fitted
a counting mechanism z the one illustrated consisting of four dials which specify
units, tens, hundreds and thousands, and allows of reckoning up to 10,000, but any
other indicating contrivance may be used. A barris furnished with a pointed
head which enters notches e in a star wheel w. This star wheel w is fixed on the
ringing crank axle q. A pin a on the bar r enters through a slot in the wall v
to the interior of the telephone and works a forked lever arm h which is pivoted
at i on the inside of the wall v. This lever arm carries a pin s'. The lever arm m
of the hook f is shown in Figure 2 in contact with the telephone line circuit
terminal which occurs when the receiver is lifted from the movable hook f; but in
its normal position the lever arm m is in contact with the bell circuit terminal.
At the
In order to be able to turn the crank for the purpose of calling attention after
taking down the receiver, the summoning subscriber is first of all obliged to pull
down the bolt r the finger-piece being provided for this purpose, whereupon the
pointed head of the bolt comes out of the notch e of the star wheel.to.
same time a pin s on the bar r acts on a fork in connection with the indicating
mechanism and the pin s' on the lever h is drawn into contact with the lever arm m.
The crank can now be turned as often as is necessary in order first of all to call
the exchange and then the desired subscriber. After finishing a conversation with
a subscriber the disconnection signal is given by further turning of the crank k and
thereafter the receiver is again hung upon its hook through the weight of which
the lever arm m is brought into contact with the pin o. On the rising of the lever
arm m the pins is moved upwards and with it the lever hand as the latter is in
connection with the pin a the bolt is pushed into its highest position as indicated
at Figure 1. Turning of the crank k is thereafter prevented until the bolt ris
again pressed into its lowest position. On the rising of the bolt r the fork g is
moved upwards by the pins and there is occasioned by this movement a unit
movement of the counting mechanism z. The counting mechanism can also be so
arranged that the indication takes place on pushing down the bolt and on the
upward movement of the latter no movement of the counting mechanism occurs.

page_text: As the indication on the dial of the counting mechanism only follows on the
movement of the bolt r and as the subscriber summoned does not require to turn the
crank and so has no need to move the bolt r the conversation is only registered on
the telephone of the summoning subscriber.
The spring tension of the counting mechanism is so adjusted that the weight of
the receiver when hung upon its hook f presses down the movable hook and at the
same time carries upwards the bolt r whereupon the pins on it acts on the fork g of
the counting mechanism to effect the registration of connection.
In order to call attention the bolt r must be moved and in order after finishing
a conversation to offer the possibility of being called the receiver must be hung
into the movable hook f by whose weight the bolt is pressed up into its normal
position. In this way a sure iudication of the use of the telephone is provided.
go
In telephonic apparatus in which call keys are used in place of ringing cranks the
bolt in connection with the indicating mechanism serves to control or indicate.
Figure 4 of the drawing represents a part of this arrangement in side view. The
bolt does not have in this case a pointed head but a flat one p' which in its highest
position engages with a notch e¹ formed in the call key to so that the call key.
cannot be pressed down before the bolt is withdrawn and thereby the counting
mechanism put into operation.
The arrangement represented in Fig. 1 may he surrounded by a case out of
which projects only the ringing crank the call key and the lower part of the bolt r.
The dial of the indicator may be covered with glass and be left visible.
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 claim is:-
1. A conversation indicator for telephones, characterized by a bolt (7) the
pointed head of which (p) in its highest position engages with a star wheel (w)
secured on the ringing crank axle, and the pins on the bolt of which is so
connected with counting mechanism (), that either the upward or downward
movement of the bolt effects a unit movement of the counting mechanism in such
a way as to indicate the number of connections made for the purpose of conversation,
whilst a pin (a) likewise fastened on to the bolt (r) is so connected with a lever
arm (h) and pin (!) that on pressing down the bolt (r) the pin (s) rests upon the
second lever arm (m) and on the upward movement of this lever arm (m) induced
by the hanging of the r.ceiver, the other lever arm hand with it the bolt r is
pressed up, and by this means the further turning of the crank is prevented
substantially as described.
2. The use of the bolt r in connection with counting mechanism and the lever
arm h with pin s¹ on a telephone with call key to the said bolt r having a flat or
peg-like form of head p¹ so that it in its highest position catches in a notch e' of
the call key, in order to prevent the pressing down of the call key substantially as
described with reference to Fig. 4 of the drawings.
Dated this 12th day of February 1895
WALLACE FAIRWEATHER,
Chartered Patent Agent,
62, St. Vincent Street, Glasgow, Agent for the Applicants.