IMPROVEMENTS IN TELEPHONIC RECEIVERS.
Year: 1882

page_text: LETTERS PATENT to Henry Alabaster, of South Croydon, in the County of
Surrey, and Tom Ernest Gatehouse, of Camberwell in the County of Surrey,
both Electricians for an Invention of "IMPROVEMENTS IN TELEPHONIC
RECEIVERS.
"
PROVISIONAL SPECIFICATION left by the said Henry Alabaster and Tom
Ernest Gatehouse at the Office of the Commissioners of Patents on the
30th October 1882.
HENRY ALABASTER of South Croydon in the County of Surrey and Tom
ERNEST GATEHOUSE of Camberwell in the County of Surrey both Electricians
"IMPROVEMENTS IN TELEPHONIC RECEIVERS
27
Our invention relates to improvements in the construction of telephonic receivers
as patented to us in conjunction with Harry Robert Kempo under dato June 7th
1882, and numbered 2675; also to the method of preparation of a part thereof,
and has for its object the louder and better communication of articulated or other
sounds.
Instead of stretching an iron or steel wire surrounded by a coil or coils between
two vibrating plates, we use a wire core, surrounded by coils as before, either
attached at one or both ends to rigid supports in the case, or suspended therein,
but in no case with the ends attached to vibrating discs. At or about the centre
of the steel or iron core thus fixed, we attach a wire or thin rod of any sound-
conducting material, preferably projecting at right angles to it. At the end of this
wire or rod we attach the vibrating plate.
We specially prepare, before insertion into the receiver, the core or wire as above
described; or, as in the receiver described in the before quoted patent Nº 2675.
1882. connecting or attached to the vibrating plate or plates.
We stretch the wire or core under longitudinal strain by any convenient tool
or appliance until a permanent set of elongation and a consequent change of
molecular structure has taken place.
We find it convenient to ensure such permanent set of elongation, by stretching
the said wire or core until it breaks, and we than use the broken parts for the
purpose as described.
We find that the abnormal molècular condition of the wire core, due to such
special method of preparation, adds largely to the loudness of the communicated
sounds or words

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Alabaster and Tom Ernest Gatehouse in the Great Seal Patent
Office on the 30th April 1883.
HENRY ALABASTER, of South Croydon, in the County of Surrey, and Tox
ERNEST GATEHOUSE, of Camberwell, in the County of Surrey, both Electricians
"IMPROVEMENTS IN TELEPHONIO RECEIVERS
"
Our invention relates to improvements in the construction of telephonic receivers
as patented to us in conjunction with Harry Robert Kempe under date June 7th
1882 and numbered 2675; also to the method of preparation of a part thereof,
which is of general applicability to a variety of forms of receivers, and hâs for
its object the louder and better communication of articulated or other sounds.
In our improved form of receiver, instead of stretching an iron or steel wire
surrounded by a coil or coils between two vibrating plates, as described in our
specification filed in pursuance of the said Letters Patent Number 2675, 1882, we
use a wire core of iron or steel, or other magnetic metal surrounded by a coil or
coils as before, but attached at either one or both ends to rigid supports in the case,
or suspended therein, but in no case with the ends attached to resonant discs as
described in our aforesaid specification. At or about the centre of the steel or iron
core, thus fixed, we attach a wire or thin rod of any sound-conducting material,
preferably projecting at right angles to it. At the end of this wire or rod we attach
the resonant plate.
In further explanation of this device we append hereto an illustration thereof.
At Figure 1, A is the core of iron, steel, or other magnetic metal, fixed or supported
in parts of the case B. The core A is surrounded by a coil or a primary and
secondary coil of wire CC through which the current or currents pass, of which
the modulations produce the articulated or other sounds.
A wire or thin rod D of any sound-conducting material is fixed anywhere in
the core A, and preferably projecting at right angles to it. Upon the extremity
of this rod is fixed the resonant disc E fitted in any convenient car-piece.
We specially prepare in the manner hereinafter described the core or wire A of
iron, steel, or other magnetic metal, before it is inserted into the receiver as above
described; or as in the receivers with single or double coils as described in our
specification numbered 2675. 1882 connecting or attached to the resonant plate or
plates.
We stretch the wire or core under longitudinal strain by any convenient tool or
appliance, until a permanent set of elongation and a consequent change of molecular
structure has taken place.
We find it convenient to ensure such permanent set of elongation by stretching
the said wire or core until it breaks, and we then use the broken parts for the
purpose as described.
We find that the abnormal molecular condition of the iron or the steel wire core
due to such special method of preparation, adds largely to the loudness of the
communicated sounds and words, and enables a clearly articulating telophonic
receiver to he constructed, when such prepared core is surrounded by only a single
coiled wire including a battery, and through which flows a variable current, one end
of the said core being left free.
This specially prepared core may be adaptable to a variety of telephonic receivers,
diverse from those more particularly described in this specification, and in that
numbered 2675. 1882, but we illustrate at Figure 2 on the drawing hereto
annexed, a form of receiver in which the improvement in clearness and loudness of
articulation is particularly due to the adaptation of our improved core.

page_text: A is the improved core or wire of iron steel or other magnetic metal prepared
with permanent set of elongation, free at one end and fixed at the other to a
resonant disc E, which is fixed by its outer circumference in the case B formed with
a convenient ear-piece. A single coiled wire C C surrounding the core, will, with
our improved core, suffice to produce loud and clear articulate sounds when a
variable current caused by a suitable transmitter passes through the said coil, either
as a primary, secondary, or tertiary circuit.
Having now described and ascertained the nature of our said invention and the
manner in which the same may be carried into effect, be it known that what we
consider novel and desire to protect by letters patent is :-
First. The construction of a telephonic receiver with a core of iron, steel, or
other magnetic metal, prepared with permanent set of elongation, suspended in, or
attached to, a case, and surrounded by a coil or coils of wire, a resonant disc being
attached to the said core by a projecting sound-conducting rod, substantially as and
for the purposes described.
Second. The method of preparation of an iron, steel, or other magnetic core or
wire by permanent set of elongation, producing molecular change, for use in
telephonic receivers, substantially as and for the purposes described.
Third. In a telephonic receiver the combination of a core prepared with a
permanent set of clongation, with a resonant disc attached to one end, the other
being free, the said core being surrounded with a coil through which flows a variable
current, as and for the purposes substantially as described.
Fourth. The combination in a telephonic receiver of a core, prepared with a
permanent set of elongation, with a resonant disc or plate attached to one or both
ends and wound with two coils, substantially as and for the purposes described in
our specification filed in pursuance of Lettors Patent dated 7th June 1882 and
numbered 2675.
In witness whereof I the said Tom Ernest Gatehouse on behalf of myself
and the said Henry Alabaster have hereunto set my hand and seal this
twenty-fourth day of April in the year of our Lord One thousand eight
hundred and eighty-three.
Witness:
JOHN. C. FELL
Patent Agent
23 Rood Lane E.C.
TOM ERNEST GATEHOUSE (L.S.)