Year: 1897

page_text: Date of Application, 18th Feb., 1897-Accepted, 10th Apr., 1897
We, GEORGE LEE ANDERS, of 33 Peak Hill Gardens, Sydenham, in the County
of Kent, Electrician and JULIUS EDWARD WEDEKIND and TINNISWOOD MILLER,
both of Clerkenwell Road, London, in the County of Middlesex, Electricians
and 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:-
The object of our invention is to provide a small concentric telephone of the direct
working type, suitable for use as a substitute for the ordinary electric push button
so as to admit of telephonic communication between various points in an ordinary
electric bell system as used in hotels, private houses etc.; and at the same time to
more nearly resemble in appearance and size the ordinary push buttons and to be
capable of similar decorations.
These improvements consist mainly of a novel method of holding the receiver
and the parts of the transmitter in their places by means of horns or lugs of special
shape projecting from the face of the transmitter, which at the same time act to
make and break the circuit between the receiver case and the transmitter.
.
The circuits as arranged in this telephone consist in providing a simple means of
breaking the circuit when the receiver is in its normal position and held by the
before mentioned lugs or horns, the signalling or bell circuit being completed by
the contact of the horns and the receiver case.
In the receiver is located a ringing key which is connected to the case and in its
normal position makes contact with a conductor in the flexible cord, the opposite
end of this conductor being connected to the terminal on the transmitter to which
the bell circuit is connected.
When the ringing key
depressed it forms a circuit from the line through the
lugs, receiver case and key through a conductor in the flexible cord to the battery
or return wire terminal on the transmitter.
A further improvement consists in the method of attaching the conductors in the
flexible cord to the terminals of the coils and bell contact in the receiver case.
This is accomplished by attaching the permanent magnets and coils to one
side of a dished piece of metal leaving just sufficient space between the magnets
and the latter to admit of the flexible cord passing between them. This space is
obtained by inserting a segment of insulating material carrying the terminals
between the dished metal and the magnets. This forms a clamp for the flexible
cord so as to take the strain off the conductors where they are attached to their
respective terminals. By this arrangement accessibility and ample room is gained
for attaching and detaching the flexible cord. The receiver case consists of
a ring of metal or other suitable material having an outside and inside flange
at one end.
Upon the inside flange rests an ear piece, diaphragm and dished piece of metal
carrying the magnets, coils and ringing key placed respectively one upon the other
and held in position by a threaded rosette or its equivalent through which the
ringing key is operated by a push button.
The object of the outside flange of the receiver case is to retain the receiver in
its position between the horns or lugs on the transmitter base.
To clearly explain our invention reference is made to the accompanying drawings
in which
Fio ea face of L

page_text: L
in place on the line - Fig 1.
Fig. 3 is a back view of the transmitter.
Fig. 4 is a horizontal section on line y-y of Fig. 1.
Fig. 5 is a section on line z- Fig 2 looking in the direction of the arrow.
Fig. 6 is a view of interior of the receiver looking at it from the ringing
key end.
"
Fig. 7 is a similar view to Fig. 4 but illustrating a modification, and in plan.
Fig. 8 is a diagram shewing the circuits.
The transmitter base consists of a preferably circular block 1 of wood, earthenware,
or other suitable insulating material in a recess in which, is contained a microphone
preferably of the kind described in the Complete Specification of an Application for
a Patent filed by two of us on the 29th of April 1896 under No. 9060 and which
microphoue consists of a light metal case 2 containing a cup shaped block, holding
carbonized fibre, which is covered by a carbon diaphragm. In the present case the
rear of the microphone case 2 projects through an opening in the base and contact
is made therewith by means of a light metal spring 3 which is connected to a
terminal 4. Above the diaphragm is a metal ring 5 having a spring switch strip 5
projecting from it as shown in Figs. 1 and 2 the end of such strip passing through a
perforated or ornamental face plate 6 which in the construction shown is mounted
on and carried by a metal ring 6 which closes the opening in the transmitter.
The parts 6 and 6" may however be in one piece. The ring 5 and switch strip
are insulated from the face plate by a distance ring 5° of insulating material
preferably attached to the upper side of said ring 5 so that contact can only be
made with the face plate through the switch strip 5.
At each side of the face plate is a shouldered horn or lug 7 a screw attached to
or forming part of which passes through to the back of the base where a nut 8 is
applied to hold it. One of these screws passes through a plate 9 (the nut 8 being
screwed on above said plate) which carries a terminal screw 10.
At the back of the base are also plates 11, 12 having terminals 11* 11° and
12ª 12ª respectively.
The receiver case consists of a metal, ring 13 having an outside flange 13 and
an inside flange 13b the latter serving to hold in place the ear piece 14 and
metal diaphragm 15 while the outer flange engages with the horns or lugs 7 serving to
hold the receiver in place and also making contact therewith. The car piece 14 is
adapted when in place to press down the spring switch 5 and break contact between
the microphone and the face place. Upon the diaphragm is a dished piece of
metal 16 cut away in places as shown in Fig. 5 and to this is secured a segment of
insulating material 17 on which is mounted the magnet 18 the two poles of which
carry on cores the usual coils 19, 19. The magnets are screwed to the insulating
segment 17 and to the piece 16 by the screws 18*. In this way a convenient means
is provided of attaching the flexible cord which connects the transmitter and
receiver as when inserted in the space between the magnet and the piece 16 it can
be clamped down when the magnet is secured in place so that any strain is taken by
the whole cord and does not separately fall upon any of the conductors comprising
same.
The conductors 22, 21, 20 are attached to the terminals 23, 24, 25, the first one 23
going to a plate 26 forming part of the ringing key and mounted on the segment 17,
the second one 24 being formed as a pin (Fig. 2) forming also a part of the ringing
key and also carrying one end of the wire of the coils and the third one 25
forming a terminal for the other end of the wire of the coils.
The last part of the ringing key consists of the usual spring strip 27 which is
secured to the magnet this strip being normally in contact with the plate 26 and
with the case. The receiver is completed by a threaded rosette 28 of insulating
material which rosette is screwed into the ring 13 and carries the usual push button.
By removing this rosette all the parts above described may be lifted out of the
ring 13.

page_text: Fig. 7 represents a modification of the face plate of the transmitter in which the
ring 6 (or it may be the ornamental plate 6) has the lugs stamped up from it the
connection with the base being made by a screw 29 which passes through a lug 30
and is in connection with a plate 9 which corresponds to the plate 9 in Fig. 3.
This face plate can be taken off from the front without removing the base from the
wall or the like by removing the screw 29 and a screw (not shewn) which holds
down a similar lug on the opposite side so that the microphone may be reached.
The holding faces of the horns or lugs 7 in both cases are formed on a curve as
shown in Fig 1 so that while a good contact may be made with the metal case of
the receiver the latter will be held securely in same and prevented from passing or
falling through.
The circuits in this instrument are as follows -When the receiver is in position
as shown in Fig. 2 and the room or place in which the instrument is situated and
which is provided with a bell is to be rung up the current is from.line to terminal 10
(see Fig. 8) by plate 9 to nut 8 to lug. 7 to receiver case 13 through the metal
portions to the ringing key 27 to the plate 26 to terminal 23 by wire 22 to terminal 12"
by plate 12 and terminal 12b by wire 31 to bell B and to return.
When the receiver is removed the current is from line by terminal 10 to lug 7
face plate 6 switch 5 microphone 2 by spring 3 to terminal 4 by conductor 20 to
terminal 25 of receiver by coils 19 to terminal 24 out by conductor 21.to terminal 11°
plate 11 terminal 11 line 32 to return.
When ringing up the circuit is broken between 26 and 27 and the current is from
battery A by wire 32 to terminal 11' wire 21 pin 24 key 27 through receiver to
ring 13 of same to lug 7 (the receiver being in place) to plate 9 terminal 10 and
to line.
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. In a telephone of the class described the means for holding the receiver and
transmitter together' consisting of horns lugs or the like such means also serving to
complete the circuit between the receiver case and a bell contact insulated from
same substantially as and for the purpose described.
2. A telephone transmitter having detachable horns or lugs on the face of same
and adapted to hold a receiver and to complete a circuit between same substantially
as and for the purpose described.
3. In a telephone of the class described a face plate carrying horns or lugs
adapted to hold a receiver such face plate being removeable from the front and
being in contact with a suitable terminal, and a receiver adapted to make contact
with such horns and lugs substantially as and for the purpose described.
4. In a telephone receiver of the class described the means for holding the
conducting cord and preventing any undue strain being put upon any of the conductors
composing same, consisting of the arrangement of parts whereby the cord is clamped
by the magnet substantially as described.
5. A receiver case consisting of a suitable ring provided with an inside and
outside flange and a screwed or removeable rosette the latter adapted to secure the
parts of the receiver in place substantially as and for the purpose described.
6. The general arrangement and construction of telephone for domestic use
substantially as described and illustrated.
CL
PHILIP M. JUSTICE,
55 & 56 Chancery Lane, London, Agent for the Applicants.