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 first to the microphonic transmitter of telephones and
consists in the combination with the compound microphone of a thin vibrating
diaphragm of mica or other suitable material. The whole of the carbon buttons of
the microphone may be placed in contact with this diaphragm or the central
carbon button only may be in contact with the diaphragm, the surrounding carbon
buttons being in contact with the frame. When the diaphragm is composed of
iron or other conducting material it should be insulated from the microphone.
By the use of a thin vibrating diaphragm in substitution for the rigid wooden
board ordinarily employed, the instrument is rendered more sensitive and the
strength of the articulations produced at the receiver is greatly increased.

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 microphonic transmitter of telephones and consists
in the combination with the compound microphone of a thin vibrating diaphragm
of mica or other suitable material-The whole of the carbon buttons of the
microphone may be placed in contact with this diaphragm or the central carbon
button only may be in contact with the diaphragm the surrounding carbon buttons
being in contact with the frame of the microphone-When the diaphragm is
composed of iron or other conducting material it should be insulated from the
microphone
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 corresponding Figures-
Figure 1 of the accompanying Drawings represents a transverse section and
Figure 2-is-an-elevation-of-a-microphonic transmitter constructed according to one
modification of my said Invention Figures 3 and 4 are views similar to Figures 1
and 2 illustrating another modification-
According to my said Invention I employ in combination with the compound
Microphone A a thin vibrating diaphragm B of mica or other suitable material
attached at its edges to the mouth piece of the apparatus
The whole of the Carbon buttons a a¹ of the Microphone may be placed in
contact with and secured to the diaphragm as shewn in Figures 1 and 2 or the
central button a' only may be in contact with and secured to the diaphragm as in
the modification Figures 3 and 4 the surrounding carbon buttons a being in contact
with the semi annular frames D of the microphone which bear upon the
diaphragm B-When the diaphragm B is composed of iron or other conducting
material it should be insulated from the Microphone by insulating material as
indicated at b in Figure 3
By the use of a thin vibrating diaphragm in substitution for the rigid wooden
board ordinarily employed the instrument is rendered more sensitive and the
strength of the articulations produced as the Receiver is greatly increased
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 hereinbefore in part
recited Letters Patent is-
In a Microphonic Transmitter the combination with the compound Microphone of
a thin vibrating diaphragm of Mica or other suitable material substantially as and
for the purposes herein before described-
In witness whereof I the said Allan Westley Rose have to this my
Specification set my hand and seal the Ninth day of June One thousand
eight hundred and eighty two.