Improvements in Telephone Receivers, Usable also as Transmitters.
Year: 1890

page_text: Date of Application, 1st Oct., 1890
Complete Specification Left, 9th May, 1891-Accepted, 1st Aug., 1891
PROVISIONAL SPECIFICATION.
Improvements in Telephone Receivers, Usable also as
Transmitters.
ARTHUR THOMAS COLLIER "Bondi" Caterham Valley Surrey, Gentleman,
do hereby declare the nature of this invention to be as follows:-
Hitherto attempts have been made to increase the power of the telephonic
receiver, with more or less success, so that messages can be heard more distinctly
as well as over a longer distance than by the instruments now in use.
These objects I accomplish by this invention so that sound waves of great power
impinge on the tympan of the ear when a message is spoken into the ordinary
transmitter connected with this telephone and the usual telephonic circuit.
The instrument consists of an electro-magnet held in the centre of a disc or
cylinder the said electro-magnet having both of its ends free to actuate a tympan
or vibrating disc (hereafter called tympan) outside of which tympans, a permanent
magnet is placed in such position that the electro magnet and tympans shall be
between the poles of the said permanent magnet.
The core of the electro-magnet is made of soft iron of larger diameter than has
hitherto been found desirable, the efficiency of this increased size depending upon
a large number of slots running longitudinally along the said core, so that the
comparatively large mass is very sensitive to magnetic variation.
The tympans may be of the usual iron plate known as ferrotype, or of pine wood,
turned from the solid with a flange left all around to give rigidity and carrying a
piece of soft iron in the centre.
The sound may be conducted to the ear from between the two tympans through
a hole in the disc or cylinder, and when desirable from the two outer sides of the
tympans through a tube to an ear piece for use with the other ear.
I have found it convenient to hold the tympans in position between each end of
the said disc or cylinder, and a case or cover and to place the permanent magnet
outside the covers, when the magnet may be mechanically utilised to hold the
covers firmly in their place on either end of the cylinder, as well as to form a
convenient handle to the instrument, and means of hanging it up when not
in use.
Dated this 1st day of October 1890.
COMPLETE SPECIFICATION (AMENDED).
Improvements in Telephone Receivers, Usable also as
Transmitters.
1, Arthur ThoMAS COLLIER, of Bondi, Caterham Valley, in the County of
Surrey, Gentleman, 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 :-
My invention relates to telephone receivers which are also useful as

page_text: The object of my said invention is to increase the power of magnetic telephones
so that messages can be transmitted over a longer distance and can be heard more
distinctly than by the instruments of this kind or class hitherto employed.
1 accomplish the desired result, by my invention, in such a manner-that, when-
message is spoken into a transmitter-(whether constructed us herein described-or
of any other suitable construction) connected in the usual manner with my improved
telephone, sound waves of great power will be caused to impinge on the tympan of
the ear of the person using the said telephone.
An important feature of my said invention is the construction of the telephone
with two diaphragms or tympans each of which is placed between two magnet-poles
or between two groups of magnet-poles, and with an ear-piece or mouth-piece
which is connected with the air-chambers or spaces between the said diaphragms or
tympans and the adjacent ends of the inner magnet or magnets.
For the purpose of my invention, I arrangesin suitable proximity to each of the
poles of an electro-magnet, which is actuated by the line-current, a diaphragm or
tympan, and provide a permanent magnet which is so arranged that the two
diaphragms or tympans are in suitable proximity to the poles thereof, respectively,
and each of the said diaphragms or tympans is situated between one of these poles
and the adjacent pole of the said electro-magnet.
The permanent magnet may be replaced by an electro-magnet actuated by a
local battery.
By the construction of the telephone in this manner. I greatly increase the
efficiency of the same. Moreover, am enabled to make the apparatus very strong
and compact, and to so construct it that the permanent magnet will conveniently
serve as the handle of the apparatus and also as the means for suspending it from
a hook or the like when it is not in use.
My said invention, moreover, comprises other improvements hereinafter set
forth.
In the accompanying drawings I have shown how my said invention may be
conveniently and advantageously carried into practice.
Figure 1 is a front elevation, and
Figure 2 is a side elevation of one form of my improved telephone.
Figure 3 is a horizontal section on the line a, a, Figure 2, and
Figure 4 is also a side elevation of the said telephone, some of the parts being
removed.
Figure 5 is a sectional side elevation, some of the parts being removed, showing
another form or modification of my improved telephone.
Figure 6 is a side elevation of this telephone, and
Figure 7 is a section on the line y, y, Figure 6, showing details of construction.
Like letters indicate corresponding parts throughout the drawings.
a is a hollow cylinder or annular disc of wood, vulcanite or other suitable
material, in the centre of which is secured an electro-magnet b. On each side of
the said cylinder or disc a is arranged a diaphragm or tympan , which is firmly
held around its edge between an annular projection on the said disc and a corre-
sponding projection on a case or cover d. In the centre of each of the cases or
covers d is fitted a flanged pole-piece e. The whole of the parts are securely held
together by means of a horse-shoe permanent magnet f, so arranged that the poles
thereof bear firmly against the flanged ends of the pole-pieces e. This magnet is
preferably secured to the covers d by means of screws or in any other convenient
manner. The diaphragms or tympans e and the covers d are preferably retained in
place upon the dise a by means of pins or studs g which extend through holes in the
diaphragm and into corresponding holes in the cover.
When each of the tympans is arranged between two magnet-poles, as above
described, the effect produced by the magnetic variations or fluctuations is much
more powerful than when the tympan is simply arranged in proximity to a magnet-
pole situated on one side thereof, as in the bell telephones hitherto employed.
The cylinder or disc a has formed therein a recess or cavity
which serves

page_text: either as an ear-piece or as a mouth-piece, and which is in communication, through
apertures or passages in the said cylinder or disc a, with the spaces between the
tympans c and the ends of the said cylinder or disc and of the electro-magnet b
enclosed therein. I prefer to make the said ear-piece or mouth-piece with a
central cone for the purpose of more effectually directing the sound-waves to the
ear or from the mouth as the case may be.
By forming the ear-piece or mouth-piece in the said cylinder or disc and con-
necting it with the spaces between the diaphragms or tympans as above described,
I provide-for-very efficiently utilizing-in-addition to the sound-waves-produced by
both tympans, the-vibrations-or-molecular-movements set-up in the sore-and-coil-of
the electro-magnet. Moreover, the sound-waves produced in the said spaces by
the vibrations of the tympans will be conducted directly to and concentrated in the
car-piece, and the sound-waves produced by the vibrations of the tympans in the
spaces between the latter and the covers will also be transmitted to the ear of
the person using the telephone, through the material of the said covers and of the
cylinder or disc a. The cylinder or disc a and the covers d form a box or case in
which are enclosed the two tympans and the electro-magnet arranged between the
same.
If deemed desirable, a suitable tube may be connected with the spaces between
the tympans e and the covers d, so that, while a person using the telephone holds
the car-piece to one ear, he can hold the said tube to the other car.
I find it advantageous to make the soft iron core b' of the electro-magnet of
larger diameter than has hitherto been found desirable, and to form in the said core
a series of longitudinal slots 62 extending from end to end thereof as shown, the
efficiency of this core of increased size depending upon the slotted formation thereof.
By making the-said-core in this manner, I provide-a-comparatively large-mass-of
soft iron which is nevertheless very sensitive to magnetic variations or Austuations.
The two ends of the wire forming the coil of the magnet bare connected in any
convenient manner with the terminals j, j'.
The tympans may be formed, as usual, of the iron plate known as ferrotype or
any other suitable iron plate, or they may be of pine-wood turned from the solid
with a flange all around to give rigidity thereto, a piece of soft iron being secured
to the pine-wood tympan at the centre thereof; or the said tympans may be formed
of any other suitable substances.
Although the form of my instrument illustrated in Figures 1 to 4 of the accom-
panying drawings is very convenient and advantageous, yet is obvious that I can,
if desired, somewhat modify the construction thereof, without departing from the
nature of my said invention. For instance, the permanent magnet may be enclosed
together with the electro-magnet and tympans within a suitable case, and the
covers d be dispensed with. The electro-magnet can, if desired, be made with a
core of any other suitable form. Instead of the permanent magnet I can, as above
stated, employ another electro-magnet actuated by a local battery. I can, more-
over, make my telephone with more than one ear-piece or mouth-piece connected
with the space or spaces between the tympans. And I can, if desired, employ more
than one pair of magnets.
In Figures 5, 6 and 7, 1 have shown a modification of my improved telephone
wherein I use three electro-magnets and a corresponding number of permanent
magnets f. The telephone shown in these figures, is provided with a tube k
furnished with an ear-piece or mouth-piece l. In these figures, moreover, I have
illustrated a convenient mode of securing the parts of the instrument together,
which is also applicable to other forms of my improved instrument, such for
example as that shown in Figures 1 to 4. For this purpose, I form in the magnets f
slots or notches f', and I pass through these slots or notches and through holes in
the covers d and cylinder or disc a, suitable stirrups or straps m formed of pieces
of wire bent to the required shape and screw-threaded at their extremities to
receive nuts n, whereby they are firmly secured in place, a metal plate or bar p
being placed between the said nuts and the adjacent surface of the corresponding

page_text: magnet f. By these means, the whole of the parts are rigidly fastened together,
and I am enabled to dispense with the pins or studs g hereinbefore described.
It is obvious that I can, if desired, employ a group of two or more electro-
magnets in combination with a single permanent magnet of suitable dimensions.
The current in the line-wire which actuates the electro-magnet or group of
electro-magnets may be alternate such as is produced by an electro-magnetic
transmitter or a carbon transmitter and induction-coil, or it may be of varying
strength but constant direction such as is produced by a carbon transmitter or
microphone acting directly.
The poles of the electro-magnet and of the permanent magnet should be situated
at such relative distances from the diaphragms respectively that the superior
attraction is exerted by the electro-magnet. The poles or pole-pieces of the
permanent magnet must not have any coils upon them through which the line-
current passes as that would seriously interfere with the action of the instrument
and operate to neutralize its advantages.
The mouth-piece may, if desired, be connected with the spaces outside the
diaphragm, but I prefer the arrangement above described viz.: wherein it is
connected with the space between the diaphragms.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I wish it understood
that I claim :-
First. A telephone provided with two diaphragms or tympans each arranged
between two magnet-poles or between two groups of magnet-poles one of which is
actuated by the current in the line-wire and the other of which is independent of
such line-current, and with one or more ear-pieces or mouth-picces connected with
the space or spaces between the tympans, substantially as herein described.
Second. The combination of an electro-magnet produced actuated by a current in
the line-wire, a solid permanent magnet so arranged that its poles are in proximity
to those of the said electro-magnet, and diaphragms or tympans situated between the
poles of the electro-magnet and those of the permanent magnet, substantially as
herein described.
Third. A telephone comprising two diaphragms or tympans, an electro-magnet
produced actuated by a current in the line-wire arranged between the said tympans
in a box or case provided with an ear-piece or mouth-piece, and a solid permanent
magnet, the poles or pole-pieces of which are in suitable proximity to the said
tympans, substantially as herein described.
Fourth. The employment, in a telephone, of an electro-magnet produced actuated
by the current in the line-wire, which is not in eontaet circuit with any independent
magnet and which possesses a solid core of comparatively large diameter formed
with longitudinal slots, substantially as shown in the drawings.
Fifth. The improved telephone constructed substantially as described with
reference to Figures 1 to 4, or with reference to Figures 5 to 7 of the accompanying
drawings, for the purposes above specified.
Dated this 7th day of May 1801
ARTHUR THOMAS COLLIER.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.