Improvements in Portable Telephones.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Portable Telephones.
I, LARS MAGNUS ERICSSON, of 5, Thulegatan, Stockholm, in the Kingdom of
Sweden, Manufacturer, do hereby declare the nature of this invention to be as
follows:
This invention relates to portable or pocket telephones and consists in an
improved method of mounting the transmitter and receiver upon a stock or
handle common to both, but in such a manner that the distance between the
two may be readily varied, without otherwise altering their relative positions or
interrupting the electrical connection to either.
In a portable telephone constructed according to this invention the transmitter
and the receiver are respectively mounted upon heads attached to tubes and rods
arranged to slide telescopically within the stock or handle. The receiver is by
preference carried upon one tube whilst the head whereon the transmitter is
mounted is carried on two rods arranged one on either side of that supporting the
receiver.
The terminals for the flexible connections are housed in a recess in the trans-
mitter-head; the circuits thence to the transmitter and receiver respectively being
arranged in the following manner. As regards the transmitter, the terminal
screw to the carbon is encircled by a metallic thimble and to the latter the flexible
connection is secured. This screw passes through the head and the cover of the
recess formed therein, a nut at its outer extremity securing the parts together.
Between this nut and the terminal thimble is interposed a spiral spring which
serves to ensure good electrical contact. The circuit from the second terminal
of the transmitter to the diaphragm is completed through the engagement of the
said terminal with one of the metallic rods whereon the transmitter-head is
mounted, thence by way of the metallic tube in which the rod slides to a plate at
the receiver end of the handle and thus to one side of a switch. The switch com-
prises a metallic strip capable of being depressed and a contact plate attached to
the handle. The said strip may be backed by a strip of insulating material and
housed in a groove in the handle. From the opposite side of the switch, the
circuit passes, by way of the other metallic rod of the transmitter-head, to a plate
against which the transmitter bears, and thence, by way of the metallic casing
of the transmitter, to the diaphragm.
The circuits from the receiver-terminals in the transmitter head to the coil
terminals of the receiver are respectively completed by means of two insulated
wires coiled in a double threaded spiral. These coils traverse the tube which
extends from the transmitter-head to the handle and through the latter and the
tube on which the receiver-head is mounted to the receiver.
The transmitter and the receiver are preferably arranged in the same plane,
the former being furnished with a hinged flap, capable of being turned to such
an angle that, when opposite the mouth, the sound is reflected into the trans-
mitter, the receiver being meanwhile placed against the ear.
When the tubes whereon the transmitter and receiver are respectively mounted

page_text: are pushed into the stock or handle, the apparatus is rendered very compact and
adapted for being carried in the pocket.
Dated this 15th day of May 1899.
Improvements in Portable Telephones.
I, LARS MAGNUS ERICSSON, of 5, Thulegatan, Stockholm, in the Kingdom of
Sweden, Manufacturer, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
This invention relates to portable or pocket telephones and consists of an
improved method of mounting the transmitter and receiver upon a stock or handle
common to both, but in such a manner that the distance between the two may be
readily varied, without otherwise altering their relative positions or interrupting
the electrical connection to either.
The accompanying drawings illustrate a portable telephone constructed accord-
ing to my invention."
Fig. 1 is a rear elevation of the apparatus in its closed condition. Fig. 2 is a
front elevation showing the apparatus extended. Fig. 3 is a part side view and
longitudinal section. Fig. 4 is a part face view and longitudinal section, the
transmitter being removed. Fig. 5 is a detached view of the interior of the
transmitter-head, and Fig. 6 a transverse section thereof taken on the line -!|
(Fig. 5).
In my improved portable telephone, the transmitter A and the receiver Bare
mounted upon heads A and B respectively attached to tubes or rods arranged
to slide telescopically within the stock or handle C. The head which carries the
receiver B is by preference carried upon the tube B whilst the head whereon the
transmitter is mounted is carried by the rods A² A³ arranged one on either side
of that supporting the receiver.
The terminals for the flexible connections are housed in a recess
a in the
transmitter-head A'; the circuits thence to the transmitter and receiver respec-
tively being arranged in the following manner. As regards the transmitter, the
terminal screw a to the carbon is encircled by a metallic thimble a¹ and to the
latter the flexible connection is secured. The screw a passes through the
head A and the cover-plate and terminates in a nut a, a spring being
interposed between the nut a2 and the thimble a¹ so as to ensure good electrical
contact, while the nut a secures the parts together. The circuit from the second
terminal of the transmitter to the diaphragm is completed through the engage-
ment of the said terminal with the extremity A of the metallic rod A2, thence by
way of the metallic tube or guide c to the plate c°, at the receiver end of the
stock or handle C, and thus to one side of a switch C. It will be seen that the
extremity A of the rod A2 is screwed into the material of the transmitter-head
while the terminal a cuts into the periphery of the said extremity, the latter
being however separated from the screw . The switch comprises a metallic
strip formed integral with the plate and capable of being depressed at its
lower extremity upon a contact plate attached to the handle. The part c¹ of
the switch may be furnished with insulating material and be housed in a

page_text: recess formed for its reception in the handle. From the contact plate c² the
circuit passes, by way of the plate c20, rod A³ and the extremity A* of the latter,
to a plate against which the inner side of the transmitter bears, the current
passing thence, by way of the metallic casing of the transmitter, to the diaphragm.
The rod A2 and tube c are insulated from the plate 2 by the washer 4, while
the rod A is in electrical connection with the said plate through the tube c³.
This tube is insulated at the upper end from the plate co by means of a washer *.
The tube is in electrical connection at its upper end with the plate c°.
The circuits from the receiver-terminals in the transmitter-head to the
coil terminals (not shown) of the receiver are respectively completed by means of
two insulated wires coiled in a double threaded spiral. The coils traverse
the tube A which extends from the transmitter-head to the handle Cand
through the latter and the tube B2 to the coil terminals of the receiver.
The transmitter A and the receiver B are preferably arranged in the same
plane, the former being furnished with a hinged flap A, capable of being turned
to such an angle that when opposite the mouth, the sound is reflected into the
transmitter, the receiver being meanwhile placed against the ear.
When the tubes A2, A and B, whereon the transmitter and receiver are respec-
tively mounted are pushed into the stock or handle C, the apparatus is rendered
very compact and adapted for being carried in the pocket.
The stock or handle C as also the transmitter-head A¹ are by preference formed
of non-conducting material.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I claim:-
1. A portable telephone constructed substantially as herein described and
having the transmitter and the receiver mounted upon tubes or rods arranged
telescopically in a stock or handle, whereby the distance between the transmitter
and the receiver may be varied without interrupting the electrical connections.
2. In a telephone, of the kind herein referred to, connecting the receiver
terminals in the transmitter-head with the coil-terminals of the receiver by means
of extensible conductors, arranged substantially as set forth.
3. In a telephone of the kind herein referred to, the employment of rods, such
as A2 A3, arranged substantially as herein described; the rod A being in electrical
connection with one terminal of the transmitter and with one contact of the
switch, and the rod A3 in electrical connection with the other contact of the
switch and with the diaphragm.