IMPROVEMENTS IN TELEPHONIC APPARATUS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by José Dottin Husbands at the Office
of the Commissioners of Patents on the 29th December 1883.
•
JOSÉ DOTTIN HUSBANDS of 4 New Broad Street in the City of London
Gentlemán "IMPROVEMENTS IN TELEPHONIC APPARATUS
""
The improvements relate firstly to the construction of Telephonic transmitters
and receivers.
In carrying out this part of my improvements I am enabled to dispense with the
diaphragm ordinarily employed for producing or reproducing the pulsations.
For this purpose I en ploy a magnet or magnets attached to or in connection
with a suitable case, plate, block or other suitable part of sufficiently resonant
material. The poles of this magnet are caused to approach and recede from each
other by means of a current passing through an electro magnetic coil or coils placed
in such a position in relation to the magnet as to give the most effectual molecular
disturbance or mechanical movement of the magnet that is to say that disturbance
which will impart the most intense vibrations from such magnet to the case or
other part or parts to which it may be connected to receive or transmit such
vibrations in the form of sound waves.
The arrangement of core which may be employed may be that described in my
Specification of Letters Patent N° 3008 of the year 1882 in which I have described
a divided core, or a core held in elastic tension.
In some cases I employ a coil or coils with the magnet or magnets as the
inducing means, having a battery in suitable connection with the primary circuit
so as to induce a secondary current in the line circuit
According to another arrangement I attach the magnet with its coil or coils to a
suitably resonant surface at or about the neutral point of the magnet in such a
manner that the disturbance of the molecules may be imparted to the material of
that surface and thereby reproduce or induce speech or other sounds
In constructing the magnets for use in telephonic apparatus I have found greatly
increased effect to be produced by forming such, magnets with the parts at their
neutral points reduced in substance to a considerable extent or such as shall enable
greater elasticity to be obtained in their magnetic action.

page_text: According to another arrangement I attach or connect the permanent magnet to
a suitable surface for receiving the sound vibrations from that magnet as they are
imparted thereto from an electro magnet placed within the magnetic field but not
attached to or connected with the permanent magnet
My improvements have reference further to means for regulating or adjusting
and operating part or parts of telephonic apparatus of the character of those
described in the specification of my patent No 3008 of the year 1882 aforesaid by
means of the attraction and repulsion of a magnet under the influence of a
current.
This adjusting or regulating means may consist of a device whereby the attraction
and repulsion of the poles of the magnet imparting motion to a strip, loop, or
other form, of metal or other suitable material attached to or in connection with a
diaphragm or other suitable surface for receiving or imparting the sound waves.
The permanent magnets may be in some cases so formed as to be capable of
adjustment by screwing or other suitable manner to the part carrying the coil, or
coil and other parts.
Another part of my improvements has reference to means for facilitating hearing
of the sounds produced by telephonic apparatus.
For this purpose I employ a shell or other suitably shaped part formed of India-
rubber or other suitable material and shaped to the contour of the ear or part of
the head and attached to or supported by the telephonic receiver, such for instance
as an ordinary Bell Telephone. This shell or other part of flexible material when
placed in proper position relatively to the ear for use will enable the hearer to
receive the sounds conveyed by the telephone with much greater facility of
perception.
By these means I am enabled to avoid compression of the parts of the ear
as in ordinary telephonic apparatus, whilst excluding extraneous or disturbing
sounds.
Another part of the Invention has reference to telephonic receiving apparatus
particularly adapted for the use of operators in central or exchange offices or
stations of telephonic systems or in places where surrounding noises interfere with
the use of telephonic apparatus.
For this purpose I employ two receiving instruments one for each ear connected
and retained in relative position by an elastic arch or band passing around the
head. This arch may consist of one or more bands of magnetized steel adapted to
form permanent magnets the poles of which are suitably placed in relation to coils
and diaphragms of the receivers in order to operate there with.
According to another modification the connecting part between the two receivers
may consist simply of an adjustable band to pass partly around the head so as to
retain the receivers in proper position for use or otherwise. This form of connection
is particularly adapted for receivers where the diaphragm is dispensed with.
The combined receiving instruments to be supported in position for use on the
operator as above described may be held by means of suitable supports carried by
other parts of the body of the operator instead of by the head, such as by means of
a yoke from the shoulder.
Another modification of this part of my invention relates to the arrangement of
magnets in the receiver. According to this I combine a permanent magnet with
an electro magnet which I place within a coil which surrounds both, so as to
obtain an increase of the effectiveness of the Instrument whilst securing lightness,
the permanent magnet assisting the operation of the electro magnet and vice versa.
In some cases when employing transmitting and receiving telephonic instruments
in which no diaphragm is vibrated in front of or near to a magnet but where the
part operates by molecular action, I combine a diaphragm with the resonant part
before referred to in order to augment the sound.

page_text: Another part of my invention has reference to an improved telephonic exchange
system in which I am able to dispense with the employment of bars, strips, and
such like parts usually employed to connect subscribers lines together.
This I effect by means of a connection placed on the annunciator in such a
manner as to be capable when operated of throwing out the resistance in the coils
of the annunciator and at the same time connecting a subscribers line by means of
the insertion of a metallic connecting plug. The armature of the annunciator may
be suitably a ljusted by the rotation or otherwise of a cam surface or other adjusting
means.