IMPROVEMENTS IN TELEPHONES
Year: 1881

page_text: LETTERS PATENT to Allan Westley Rose of Kirby Street Hatton Garden
in the County of Middlesex for an Invention of "IMPROVEMENTS IN
TELEPHONES.”
PROVISIONAL SPECIFICATION left by the said Allan Westley Rose at the
Office of the Commissioners of Patents on the 12th December 1881.
. ALLAN WESTLEY ROSE of Kirby Street Hatton Garden in the County of
Middlesex. "IMPROVEMENTS IN TELEPHONES."
My Invention relates to the receivers of telephones of that class in which
articulate sounds are received by disturbing the statical charge of a circuit.
One mode of constructing receivers of this description has been to fit two plates
or diaphragms at a short distance from each other in a suitable case one of such
plates being connected with the secondary coil of an induction coil and the other
plate with earth. According to my present Invention I employ a rigid disc
divided into two parts which are separated by insulating material and I connect
one half of the disc with the secondary wire of an induction coil and the other
half with earth or with a return wire when metallic circuits are used.
Opposite this divided disc is a metal diaphragm secured at its edges and
arranged at a short distance from the disc. The secondary current passes from
line to one half of the disc across to the diaphragm and back to the other half of
the disc and thence to earth or to the return wire as the case may be.
By this means I obtain two positive semivibrations of the diaphragm for
each electric pulsation and thus secure a louder and better articulation from the
receiver.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Allan Westley Rose in the Great Seal Patent Office on the
12th June 1882.
ALLAN WESTLEY ROSE of Kirby Street Hatton Garden in the County of
Middlesex. "IMPROVEMENTS IN TELEPHONES."
My Invention relates to the receivers of telephones of that class in which
articulate sounds are received by disturbing the statical charge of a circuit.
One mode of constructing receivers of this description has been to fit two plates
or diaphragms at a short distance from each other in a suitable case one of such
plates being connected with the secondary coil of an induction coil and the other
plate with earth. According to my present. Invention I employ a rigid disc
divided into two parts which are separated by insulating material and I connect
one half of the disc with the secondary wire of an induction coil and the other
half with earth or with a return wire when metallic circuits are used. Opposite
this divided disc is a metal diaphragm secured at its edges and arranged at a short
distance from the disc. The secondary current passes from line to one half of the
disc across to the diaphragm and back to the other half of the disc and thence to
earth or to the return wire as the caso may be
By this means I obtain two positive semi-vibrations of the diaphragm for
cach electric pulsation and thus secure a louder and better articulation from the
receiver
And in order that my said Invention may be fully understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings the same letters of reference
indicating corresponding parts in all the Figures.
Figure 1 of the accompanying Drawings represents a section of a telephonic
receiver constructed according to my said Invention. Figure 2 is a plan of the
same with the mouth piece removed Figure 3 is a diagram sectional view drawn
to an enlarged scale illustrating the direction of the electric current Figure 4
is a similar view illustrating a modification of the divided disc herein before
referred to.
In Figures 3 and 4 the distance between the divided disc and diaphragm is
exaggerated for the sake of clearness of illustration.
a a¹ are two rigid half discs of conducting material which are separated by an
insulating strip b the latter being either formed in one with a carrier piece B
of non conducting material as shewn or attached to the said carrier piece One
of the half discs say for example the half a is connected with the secondary wire of
an indication coil by a terininal c and the other half disc a¹ is connected by
a terminal c¹ with earth or with a return wire when metallic circuits are used→
Opposite the two half discs a a¹ is a metal diaphragm C secured at its edges by
the mouthpiece D so as to be situate in very close proximity to the half discs a a¹
without being in actual contact
The secondary current passes from the line to the half disc a (see Figure 3)
across to the diaphragm C and back to the half disc a' and thence to earth or to
the return wire as the case may be
It is not essential that the two half discs should be in the same plane as they
may be arranged at an angle to each other as indicated in the diagram Figure 4
and a similar result be obtained.
By means of my Invention I obtain for each electric pulsation two position
semi-vibrations of the diaphragm that is to say the diaphragm is first bulged

page_text: outwards by the passage of the current across from one half disc to the diaphragm
and is then brought back by the return of the current to the other half disc and a
louder and better articulation from the receiver is secured.
Having now described and particularly ascertained the nature of my said
Invention and the manner in which the same is or may be used or carried into
effect I would observe in conclusion that what I consider to be novel and
original and therefore claim as the Invention secured to me by the herein before
in part recited Letters Patent is
In telephonic receivers operated by disturbing the statical charge of a circuit
the employment of a rigid divided disc or conducting body and a diaphragm
arranged and combined together substantially in the manner and for the purpose
hereinbefore described.
In witness whereof I the said Allan Westley Rose have to this my
Specification set my hand and seal this Ninth day of June One thousand
eight hundred and eighty two.
A. W. ROSE. (L.S.)