IMPROVEMENTS IN TELEPHONIC APPARATUS
Year: 1882

page_text: LETTERS PATENT to William Robert Lake of the firm of Haseltine Lake
い
& Co, Patent Agents Southampton Buildings, London for an Invention' of
"IMPROVEMENTS IN TELEPHONIC APPARATUS Communicated to him from
abroad by George Meelin Torrence of Philadelphia, Pennsylvania, United
States of America.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 16th December 1882.
اية
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and Co, Patent
Agents, Southampton Buildings, London, "IMPROVEMENTS IN TELEPHONIC
APPARATUS [A communication to him from abroad by George Meelin Torrence
of Philadelphia, Pennsylvania, United States of America.]
"
This invention relates to telephonic apparatus and comprises a transmitter and
a receiver both of novel construction.
With respect to the transmitter the said invention consists mainly in supporting
one of the electrodes of a microphone in contact with the other electrode by the
attraction or repulsion existing between permanent magnets. This I do by freely
pivotting and suspending at the upper end a bar magnet or a bar of any material
the free end of which is made susceptible of magnetic influence by attaching
thereto a magnet or magnetic material. Or the magnet or bar may be supported
by resting its lower end on a base for the purpose of holding said magnet or bar in
front of the electrode attached to a diaphragm. So that an electrode attached to
the magnet or bar will when in proper position make contact with the electrode
attached to the diaphragm. The magnet or bar is held in working position by the
attraction or repulsion exerted on its free end by permanent magnets or magnetic
material placed radially about its free end. Or the magnet may be held in its
working position and contact of the electrodes regulated by attraction of said
magnet for an armature of steel or iron secured to the frame and adjusted by a
suitable screw.
It is obvious that if the free end of the bar is terminated with an
armature only, there must be magnets to hold it in adjustment, while if the bar is
terminated with a magnet or is itself a magnet it may be retained in its working
[Price 6d1

page_text: position by the attraction or repulsion of other magnets or pieces of magnetic
material placed radially about its free end.
In carrying the said invention into practice an oscillating magnet or bar is held
in suspension at the upper end by two points or trunnions from a projecting bracket
which is attached to the frame so as to allow the lower end of said magnet or bar
to swing free. Or it may be supported at the lower end allowing the upper end to
oscillate freely, the said magnet or bar in either of the devices being held in its
working position so as to bring an electrode attached to the same into contact with
another electrode attached to the diaphragm by the attraction or repulsion of
permanent magnets or pieces of magnetic material, which are placed radially about
the free end of said oscillating magnet or bar. The latter is provided with a block
of carbon or its equivalent which is attached to the magnet or bar in any suitable
manner and is placed upon the same opposite a platina point which is attached to
the diaphragm. The adjustable permanent magnets or bars of magnetic material
are arranged that one of them is held in its position by passing it through a hole
in the frame, the other magnet being supported in its position by a bracket or
bridge. The electric battery current is conducted by a wire to the carbon to which
the wire is attached in any suitable manner. The oscillating magnet or bar
whether in the suspended or supported form is at the free end adjusted in its
working position by means of the attraction or repulsion of the poles of the said
,adjustable magnets or pieces of magnetic material acting on its free end. These
radial magnets are adjustable by moving them to or from the free end of the
suspended or supported oscillating magnet or bar and thus the force of contact of
the electrodes is regulated. Attached to the frame is a spring or compress the
under side of the free end of which is provided with a pad of any suitable non
conducting material and rests upon the diaphragm for the purpose of holding a wire
or its equivalent firmly upon the diaphragm. Said wire is attached to the diaphragm
electrode and passes under the pad and on the diaphragm and from thence is
conducted to the ordinary induction coil. Said compress also acts as a damper to
tone the vibrations of the diaphragm. The compress is secured to the frame by a
suitable screw which it is obvious serves to adjust the pressure upon the diaphragm.
Said diaphragm preferably 'made of mica is pierced at.or near its centre to receive
the platina point or electrode which is secured to said diaphragm by two metallic
discs or cleats. Said discs, or cleats also serve to hold the wire or its equivalent to
the electrode or platina point. The periphery of said diaphragm is surrounded by
an india rubber gasket, or band or any suitable non-conducting material and is
held upon the frame by suitable clamps or in any manner that will hold it firmly
to the frame. The frame being provided with an aperture, for the purpose of
conveying sounds to the diaphragm. "The microphone thus described is intended
to be used in a closed circuit.
I also construct according to this invention a telephonic receiver in which the
sound is sharp distinct or well defined without the ringing and singing so often
accompanying telephonic receivers. For this purpose I provide an annular magnet
which is divided and one end is turned inwardly and then outwardly at the centre
forming a secondary pole upon which a spool is fitted, the split or divided magnet
forming the poles on the upper and outer ends.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Robert Lake in the Great Seal Patent Office on the
16th June 1883.
"
WILLIAM ROBERT. LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
Southampton Buildings, London "IMPROVEMENTS IN TELEPHONIC APPARATUS
A communication to me from abroad by George Meelin Torrence, of Philadelphia,
Pennsylvania, United States of America.
This invention relates to telephonic apparatus, and comprises improvements in
both transmitters and receivers.
The improvements in the transmitter relate to that class of instruments known
as microphones wherein a diaphragm is in connection with a platinum point and a
block of carbon, which constitutes the electrodes; and this part of the said invention
consists essentially in supporting one of the electrodes of a microphone in contact
with the other electrode by the attraction or repulsion existing between permanent
magnets. This I do by freely pivotting and suspending at the upper end a bar-
magnet or a bar of any material, the free end of which is made susceptible of
magnetic influence by attaching thereto a magnet or magnetic material; or the
magnet or bar may be supported by resting its lower end on a base for the purpose
of holding the said magnet or bar in front of the electrode attached to a diaphragm,
so that an electrode attached to the magnet or bar will, when in proper position,
make contact with the electrode attached to the diaphragm. The magnet or bar is
held in working position by the attraction or repulsion exerted on its free end by
permanent magnets or magnetic material placed radially about its free end; or it
may be held in position and the contact of the electrodes regulated by the
attraction of the said magnet towards an armature of steel or iron secured to the
frame and adjusted by a suitable screw.
It is obvious that if the free end of the bar is terminated with an armature only,
there must be magnets to hold it in adjustment, while if the bar is terminated with
a magnet or is itself a magnet, it may be retained in its working position by the
attraction or repulsion of other magnets or pieces of magnetic material placed
radially about its free end.
The improvements in the receiver consist essentially in the novel construction'
and arrangement of parts as hereinafter described.
In the accompanying drawing
Figure 1 is an elevation of a transmitter constructed according to this invention.
Figure 2 is a vertical transverse section shewing the bar-magnet suspended.
Figure 3 is a similar section shewing the bar-magnet supported
Figure 4 is a similar section shewing the position of an adjustable armature.
Figure 5 is a detail view shewing the platinum point attached to the diaphragm
and a spring
Figure 6 is a detail view shewing the position of the radial magnets.
Figure 7 is a side elevation of a receiver constructed according to this invention;
Figure 8 is a longitudinal section of the same
Figure 9 is an end view of the same shewing the cap or core removed, and
Figure 10 is a perspective view of the magnet detached.
Referring to Figures 1 to 6 which illustrate the improved transmitter
A indicates the diaphragm; B the platinum point or one of the electrodes
C the front plate or door of the instrument; D the oscillating magnet or bar;
E E brackets; E' a supporting base for the magnet or bar; El a staple or guide
around the top of the magnet; E a bridge or bracket which supports one of the
magnets or pieces of magnetic material; F the block of carbon or the electrode

page_text: attached to the magnet or bar; G an armature attached to the frame;
G G adjustable permanent magnets or bars of magnetic material; H a battery
wire; Ja pressure bar or spring; K a wire or its equivalent attached to one of the
electrodes; a b discs or cleats for attaching the électrode to the diaphragm and also
serving to hold the wire K. or its equivalent to the said electrode; d an india-
rubber gasket or band; e clamps or binders for fastening the diaphragm to the
frame or door of the microphone; and n and 's north and south poles of the
permanent inagnets.
-
The magnet or bar D, as shewn in Figure 1 is held in suspension at the upper
end by two points or trunnions on a projecting bracket E, which is attached to the
frame C so as to allow the lower end of the said magnet or bar to swing free; or it
may be supported at the lower end as shewn at E Figure 3, allowing the upper
end to oscillate freely in a wire staple E", the magnet or bar D in either of the
devices shewn being held in its working position so as to bring the electrode F
attached to the said magnet or bar into contact with the electrode B attached to
the diaphragm A, by the attraction or repulsion of the magnets or pieces of
magnetic material G G which are placed radially about the free end of the said
magnet or bar D.
The magnet or bar D is provided with a block of carbon F or its equivalent
which is attached to it in any suitable manner and is placed upon it opposite the
platinum point B, which is attached to the diaphragm A, the magnets G G being
so arranged that one of them is held in position by passing it through a hole in the
frame C, the other magnet being supported in its position by a bracket or
bridge E The electric battery current is conducted to the carbon F by the
wire H which is attached to it in any suitable manner. The magnet or bar D,
whether in the suspended or supported form, is at the free end adjusted in its
working position by means of the attraction or repulsion of the poles of the
magnets or pieces of magnetic material G G acting on its free end. These radial
magnets are adjustable by moving them to or from the free end of the suspended
or supported magnet or bar D, and thus the force of contact of the electrodes is
regulated.
Attached to the frame C is a spring J, the under side of the free end of which is
provided with a pad of any suitable non-conducting material and rests upon the
diaphragm A for the purpose of holding the wire K, or its equivalent, firmly upon
the said diaphragm. The said wire K is attached to the electrode B, and passes
under the pad J and on the diaphragm A; and then is attached to an ordinary
induction coil. The said spring J also acts as a damper to tone the vibrations of
the diaphragm and is secured to the frame C by a suitable screw which it is
obvious serves to adjust its pressure upon the diaphragm. The said diaphragm,
when made of mica, is pierced at or near its centre to receive the platinum point or
electrode B which is secured by the two metal discs or cleats a b, which also serve
to hold the wire K, or its equivalent, to the said electrode or platinum point.. The
periphery of the diaphragm A is surrounded by an india-rubber gasket or band or
any suitable non-conducting material, and is held, upon the frame C by suitable
clamps e or in any manner whereby it is held firmly to the frame C the latter
being provided with an aperture for the purpose of conveying sounds to the
diaphragm A. The microphone thus described is intended to be used in a closed
circuit..
Although I have described this part of the said invention in connection with
permanent magnets, I may if desired, use electro-magnets or solenoids but I prefer
permanent magnets as they are more easily adjusted to regulate the contact between
the electrodes.
Referring to Figures. 7 to 10 which show a receiver constructed according to this
invention. A indicates the head, case, or shell which has thereon a knob a to
facilitate handling. Bindicates a cap which has a central opening b, and the,
exposed or outer face of which is made to converge towards the said opening;
CC are, binding posts.,

page_text: :D indicates an improved magnet-which is circular in form though not a complété
annulus as it is severed or slit vertically as shewn at c.
E is a horn or extension attached to, or forming a prolongation of, one pole only
and projecting radially inward 'to, or nearly to, the centre of the magnet and thence
extending vertically upward to receive the spool F which is mounted on the
vertical or upwardly projecting arm of the horn E which latter serves as a spindle
or core for the said spool.
G is the wire or inducing coil one end of which passes to the binding post C and
the other end is wound to and fro, on the outside or periphery of the magnet,
passing over pins' d d as shewn, it is then carried through the magnet to the other
binding post C In order that the part of the wire which is wound around the
outside or periphery of the magnet may not be injured by contact with the case I
provide the magnet with a flange as shewn at e e to prevent the wire from slipping
over the edge of the said magnet.
:
H is an india-rubber gasket or mat placed between the base of the magnét and
the case A which serves by its elasticity to secure. a closer contact between the
upper surface or edge of the magnet and the periphery of the disc I, when the cap
or cover B is fitted on the case 4, and also plays an important part in giving to the
magnet a mass vibration which I believe, in combination with the molecular
vibration resulting from changes in magnetic tension, modifies and renders audible
fine details of articulation unknown in instruments of ordinary construction; 'as
shewn in the drawing the magnet D, horn E, and the spindle or core are made in
one piece whether cast or forged. I consider that mode of construction preferable
but the horn or core can be made separate from the magnet and afterwards
secured thereto in any suitable manner. The magnetization of the incomplete
annulus may be effected in any suitable manner for example by the temporary
contact of its ends (which are opposite to each other at the slit as described). with
the respective poles of a powerful electro-magnet.
It is not absolutely essential that the wire G should be wound to and fro on the
outside of the magnet D, but I prefer to so wind that part of the magnet as its
magnétic inducing action is thereby modified.
I is the disc or diaphragm of magnetic metal. The said disc rests on the upper
or outer edge of the magnet D, thus becoming an armature. I am aware that a
diaphragm supported at its periphery by magnetic poles of unlike name to that
opposed to the centre of the said diaphragm is not new, but in this form of
telephone, the diaphragm is supported by: two opposite poles which induce in the
said diaphragm a complex magnetic condition not easily explained, but which, in
conjunction with the single polarity of the central arm of the magnet, produce
more clear and perfect articulation. The iron diaphragm acts in some degree as an.
armature or keeper with reference to two points at least of the magnet, that is the
two ends of the incomplete annulus. The two poles of the incomplete annulus
proper, being bridged by, and in contact with, the diaphragm armature, induce
therein as before stated a complete magnetic condition.
In this condition it then
becomes, without contact, an armature to the central core, becoming still more
complex in its condition as it vibrates towards or away from the same; and the
mass movement or vibration of the magnet allowed by its elastic support, and
imparted thereto by, but not synchronous with, that of the diaphragm, gives clear
and due definition to obscure tones, as before set forth. The winding of the
insulated wire around the incomplete annulus in the line of its polarity, hereinbefore
alluded to, adds another useful element to the combination and increases the
effectiveness of the instrument.
Having thus fully described the said invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood.
that I claim
First. In a microphone transmitter, a diaphragm carrying one electrode, in
combination with a bar susceptible of magnetic induction freely supported and
carrying another electrode, and two other bars or bodies acting magnetically upon

page_text: the said supported bar, so as to attract or repel the same in opposite directions,
substantially as described.
عالم
1..Ji
Second. In a microphone transmitter, a bar-magnet carrying an electrode and
pivotted at one end so as to allow the other end to move freely, in combination
with a diaphragm carrying another electrode, and adjustable magnets arranged to
act on the free end of the said bar-magnet so as to attract or repel the same in
opposite directions, substantially as, and for the purposes, set forth.
יר
Third. In a microphone transmitter, a diaphragm of mica, pierced to receive an
electrode, in combination with the said electrode, bar-magnet carrying another
electrode and pivotted at one end so as to allow the other end to move freely, and
adjustable magnets acting on the free end of the said bar-magnet so as to attract or
repel the same in opposite directions, substantially as described, and for the purposes
set forth.
"
Fourth. In a telephonic receiver, an incomplete annulus permanently magnetic,
the magnetic poles being opposite each other at the break in the said annulus and
having a neutral point nearly diametrically opposite the said break, the said
annulus supporting by its periphery a magnetic circular diaphragm and having in
its centre a vertically projecting arm connected with one pole only of the said
annulus and encircled by coils of insulated wire, substantially as described.
Fifth. In a telephone receiver, the combination of a permanent magnet in the
form of an incomplete annulus having its poles at the break, with a core, projecting
centrally and vertically from one end of the said incomplete annulus, carrying a
coil of insulated wire, insulated wire wound to and fro on the outer face of the
annulus which wire is electrically connected with the said coil, a diaphragm of
magnetic material in contact with the annulus but not with the core, and' an
elastic support for the magnet, all substantially as described:
.114
די
In witness whereof 'I the said William Robert Lake have hereunto set my
hand and seal this Fifteenth day of June in the year of our Lord One
thousand eight hundred and eighty three.
71 DADE
TATT