Improvements in and connected with Telephones for Domestic Use.
Year: 1896

page_text: Date of Application, 29th Apr., 1890
Complete Specification Left. 29th Jan.. 1897-Accepted. 3rd Apr.. 1897
Date
on, 29th Apr., 1890
Complete Specification Left. 29th Jan.. 1897-Accepted. 3rd Apr.. 1897
PROVISIONAL SPECIFICATION.
Improvements in and connected with Telephones for Domestic Use.
We GEORGE LEE ANDERS 33 Peak Hill Gardens Sydenham S.E. and JULIUS
EDWARD WEDEKIND Ferndale, Beckenham Grove Shortlands do hereby declare the
nature of this invention to be as follows:-
The object of these improvements is to provide a small concentric telephone of the
direct working type, suitable to be used as a substitute for the ordinary "press button"
as used in private houses, hotels, &c.; thereby affording verbal communication. The
same having few parts, and arranged to be readily understood and installed by persons
having no technical knowledge of telephonic apparatus. And further that these
improvements shall admit of a ready and reliable renewal of the microphonic part
whenever necessary, without disturbing the connecting wires of the base.
Also to the use of such material as porcelain in construction of the transmitter base
and the receiver case. And again the arrangement of the circuits of the transmitter
so that it is adapted to be used with an independent or separate bell wire to call
distant rooms from a central point.
In order to accomplish these results, 1 take a circular base of porcelain pierced
with suitable holes for holding the parts together. In the front of this base is a
circular recess of suitable dimensions, to hold a microphone which is complete in
itself as regards filling and adjustments, and capable of being readily inserted and
removed from the recess in the base without disturbing the latter from wall or other
support, or without disturbing the wires connected to the base. This is accomplished
by making the "face plate," switch, and yoke detachable as one piece by removing
the screws which hold it and connect it to the terminals at the back of the base. The
object being to put in a new microphone without disturbing the other parts of the
apparatus.
In a similar manner the receiver parts such as the magnets, coils, terminals and
ringing key, are all attached to one side of a metal disc having an air space
recessed into it on the opposite side: on the latter side is placed a magnetic diaphragm,
the coils of the magnets project through an opening and act on this diaphragm. The
whole of these parts are fastened together and adjusted as a whole, which is capable
of being inserted into any kind of a case, such as porcelain, without disturbing the
adjustment. The circuits of this telephone are arranged as follows:-
On the back of the porcelain base are four terminals, two of which are in contact
with the face plate, to one of these is attached the line, and bell wire; to the other is
attached a conductor in the flexible cord connected to the receiver where it is
normally "open."
A third terminal is connected to a battery wire, one side of the receiver coils
is connected to this third terminal, and the opposite side of the coils is connected to a
fourth terminal. From the latter terminal, the circuit passes through the material to
this diaphragm. When the receiver is removed from its yoke the circuit will be
completed by the switch coming into contact with the diaphragm, from the battery to
the line through the receiver and transmitter.
When the ringing key is depressed the circuit will then be through the flexible
cord from the face plate, and line to the ringing key in the receiver; this ringing
key is in contact with the battery or return wire.
When it is desired to ring a bell at any point in the system a second return wire is
necessary, and to this return wire is attached the bell, the opposite side of the bell

page_text: being connected to the terminal in the base of the transmitter, the latter being in
contact with the face plate.
Dated this 29th day of April 1896
GEORGE LEE ANDERS.
JULIUS EDWARD WEDEKIND.
Improvements in and connected with Telephones for Domestic Use.
We, GEORGE LEE ANDERS, of 33 Peak Hill Gardens, Sydenham in the County of
Kent, Electrician, and JULIUS EDWARD WEDEKIND of Ferndale Beckenham Grove
Shortlands in the County of Kent Electrician and Engineer, 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 :-
Our invention relates to certain improvements in and connected with telephones for
domestic use the object of same being to provide a small concentric telephone of the
direct working type suitable for use as a substitute for the ordinary "press button"
employed for electric bells in houses and the like so that verbal communication may
be obtained in addition to a signal or call. The improved apparatus which constitutes
our invention has few parts and is arranged so that it may be readily understood and
installed by persons having no technical knowledge of telephonic apparatus.
An apparatus constructed according to our invention admits of a ready and reliable
renewal of the microphone portion whenever necessary without disturbing the
connecting wire or the base while in the arrangement of the circuits it is adapted to
be used with an independent or separate bell wire to call distant rooms from a central
point.
In the construction of the transmitter base and receiver case we are enabled to
employ porcelain or other suitable material.
In order to accomplish these results we take a circular base of porcelain pierced
with suitable holes for attaching the parts thereto. In the front of this base is a
circular recess of suitable dimensions to hold a microphone which is complete in
itself, as regard filling and adjustments and capable of being readily inserted and
removed from the recess in the base without disturbing the latter from the wall or
other support or without disturbing the wires connected to the base. This is
accomplished by making the "face plate," switch and yoke, detachable as one piece
by removing the screws which hold it and connect it to the terminals at the back of
the base. The object being to put in a new microphone without disturbing the other
parts of the apparatus.
In a similar manner the receiver parts such as the magnets coils terminals and
ringing key are all attached to one side of a metal disc which has an air space recessed
into it on the opposite side, on which latter side is placed a magnetic diaphragm, the
coils on the magnets projecting through an opening and acting on the diaphragın.
The whole of these parts are fastened together and adjusted as a whole which is
capable of being inserted into any kind of a case such as porcelain without disturbing
the adjustment.
To clearly explain our invention reference is made to the accompanying drawings
in which
Fig. 1 is a face view of the transmitter.
Fig. 2 is a section on line - Fig. 1 with the receiver in place.
Fig. 3 is a rear view of the transmitter.
Fig. 4 is a side or edge view of the microphone case.
Fig. 5 is a section of a portion of the face or protecting plate of the transmitter to
show a switch taken on line wo wo of Fig. 1.
Fig. 6 is a section through the receiver on line y-y looking to the left.

page_text: Fig. 7 is a similar section through the line 2-2.
Fig. 8 is a diagram illustrating the circuits.
The transmitter consists of a base 1 having a recess in which is received the
microphone portion 2. This as stated is complete in itself and consists of a light
metal (preferably aluminium) cupped dise 3 in which is held by a screw or otherwise
a carbon cup shaped block 4, containing a carbonized fibre or other suitable material.
On this block fits snugly a flanged metal dise 5 on which is cemented or secured a
dise of wadding felt or other suitable material 6 to afford a yielding support for a
diaphragm 7 and to prevent the escape of the powdered material. The rim of the
diaphragm rests upon an annular packing ring or washer 8 of millboard or some
suitable insulating material such washer being cemented or secured to the edge or rim
of the metal disc 3 and also to the rim of the diaphragm 8 so that as shown in Fig. 4
a self contained encased microphone part is the result. The diaphragm 7 preferably
consists of a thin sheet of solid carbon though it may be of other suitable material.
The ring 8 forms a convenient means of adjusting and providing the necessary
spacing or distance between the diaphragm and the cupped block and powdered
carbon.
The microphone is retained in place in the recess by a packing ring or washer 9 of
insulating material and the whole is secured by the face plate 10 (Figs 1, 2 and 5)
which is screwed to the face of the base 1.
This face plate 10 has an ornamental perforated plate 11 secured to or forming part
thereof as shown in Figs. 1. 2. 5 which protects the carbon diaphragm.
At the back of this is hold a switch which consists of a four armed piece (Fig. 1)
two arms 12. 12 of which are held so as to rock tilt or pivot in holes in the plate 1.0
the third arm 13 being turned inward to form a contact maker with the carbon
diaphragm which it reaches if desired through a slot or opening 14 (Fig. 2) in the
washer 9. Beneath this arm 13 is a spring strip 13 which maintains the arm 13 in
the position shown in Fig. 5 which will keep it in contact with the diaphragm.
The fourth arm 15 projects through the perforated plate 11 (and is nosed or rounded
as shown) into the portion enclosed by the yoke 16 which completes the face
plate 10.
The face plate 10 is secured to the base by screws two of which 40. 40 engage
with metal screwed sleeves 42. 42 in such base as shown in Fig. 2 and with such
sleeves at the back engage terminal screws 43. 44 the screw 43 passing through a
plate 45 in which are two terminals 46. 46°. In addition there are also terminals 47
and 48 the latter being in contact with a metal strip 49 which makes contact in turn
with the metal disc 3 of the microphone as shown in Fig. 2.
The yoke is adapted to receive the ear piece 17 of the receiver which ear piece is
shaped on its exterior to enable it to be slid or dropped into the yoke. This ear piece
and the plate or disc 17" of which it forms a part is screwed or otherwise held by a
flanged metal ring 18 which embraces a shoulder 19 on the porcelain or other body of
the receiver 19. The plate or disc 17 is recessed as shown in Fig. 2 to clear the
metal diaphragm 20 which is held between the back of such plate or disc 17 and a
metal plate or disc 21 which has an air space recessed in it on this side as shown in
Fig. 2 and is also provided with an opening 22 through which projects the pole and
coil 23 of the magnet which is carried on the opposite side of said plate or disc 21.
This magnet is a semicircular shaped iron ring 24 Fig. 7, having a small angle
bracket 25 attached to it which supports a core on which is mounted the coil 23.
At the back of the magnet ring 24 is a dise or plate 26 of vulcanized fibre or other
suitable insulating material which is secured by three long screws 27 (Figs. 2 and 6)
to the metal plate 21 so that the magnet is held in place. At the rear of the
disc or plate 26 is secured by a screw or bolt 28 a spring arm 29 forming part
of an ordinary ringing key the free end of such arni making contact with one of the
screws 27 as shown in Fig. 6.
It will be seen that by removing the ear piece, the plate 21 with the magnet, coils
and ringing key are readily removed from the case 19 of the receiver. A hole 30 in
the case of the receiver enables a flexible cord carrying three wires to pass through

page_text: such cord connecting the receiver and transmitter. Two of such wires are connected
to the coil of the magnet and the third to the screw 28 of the ringing key.
When the receiver is in the transmitter and the apparatus is placed say in a sitting
room and it is desired to communicate with a central point where an indicator, bell,
battery, and a telephone are situated, the ringing key is depressed the circuit is then
made from the battery A through the telephone T and bell B and indicator drop C, to
the line and terminal 46, from thence by plate 45 to screw 43 to the face plate 10, to
screw 44 through the wire of flexible cord to screw 25 in receiver, through the
ringing key to screw 27 through the metallic portion of the receiver to the wire of
the flexible cord which is connected to the terminal 47 of the transmitter which is
again connected to the return wire.
Both receivers being removed, the speaking circuit is then from the line to
terminal 46 through plate 45 and screw 43 to the face plate 10 and four armed
switch which is now in contact with the diaphragm, through the microphone 2 to
the strip 49, and terminal 48, through the flexible cord and coil 23 of receiver, back
through flexible cord to terminal 47 and to the return wire.
It will be seen that with the above arrangement no battery is required in the
room in which our improved apparatus is situated so that the latter can be'
substituted for an ordinary bell push in a house or the like which is already wired for
-electric bells.
In the above arrangement the terminal 46 is not used. Where however it is
required to ring both ways so that the room in which our improved apparatus is
situated may be rung up the circuit is that illustrated by dotted lines in Fig. 8
that is to say a push Di provided to make contact with the line and a separate
battery E. When the push is depressed the circuit is from the battery through the
push and line to terminal 46 through plate 45 to terminal 46" and through the bell F
to return wire G of battery E.
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 transmitter a microphone constructed substantially as described
in combination with a base or its equivalent whereby the said microphone may be
readily inserted or removed without disturbing said base or the wires connected to it
from the wall or its support.
2. In a
telephone transmitter the construction of combined face plate, switch and
yoke, substantially as and for the purpose set forth.
3. In a telephone transmitter the combination with a base such as 1 of a
removeable microphone portion such as 2 and means such as a face plate 10
for securing the latter in place and whereby it may be readily removed substantially
as described.
4. In a telephone receiver the combination with the magnet coils, and ringing key,
of a plate to which these parts are secured, said plate forming a support for the
diaphragm and being adapted to be removed from the ear piece end of the instrument
substantially as described.
5. In a telephone transmitter of the class described the arrangement of terminals
such as 46. 46 whereby the latter provides a point for an additional bell circuit
substantially as and for the purpose described.
6. The improved construction and arrangements of telephones for domestic use
substantially as described and illustrated in the accompanying drawings.
Dated this 29th day of January 1897.
PHILIP M. JUSTICE,
Chartered Patent Agent,
55 & 56 Chancery Lane, London, For the Applicants.