DIAPHRAGMS FOR TELEPHONIC PURPOSES
Year: 1884

page_text: "
I GORHAM GRAY at the office for patents 323 High Holborn in the County of
Middlesex, do hereby declare the nature of the said invention for DIAPHRAGMS
FOR TELEPHONIC PURPOSES' to be as follows:-
These diaphragms are similar to ordinary metal diaphragms, but are preferably
made of glass, as I find glass to be a more prompt articulate exact and sensitive
reproducer than any other material known to me. It is in fact a more active agent.
I make my diaphragms whether of glass or not larger or smaller in diameter
according to the requirements of the case, thus for an ordinary earphone a small
diaphragm of a couple of inches or so across is sufficient, but where it is desired
that the sound is to be audible to a whole room or large space without applying
the instrument to the ear, or the ear to the instrument I greatly increase the
diameter for instance to eight or ten inches or more.
These Diaphragms may be used as transmitters as well as Receivers.
Should it be desirable to converse privately and quietly a funnel shaped trumpet
may be used having a cone to cover the Diaphragm with another cone connecting
with the first by a short piping for application to the ear for receiving and for
application over the mouth for transmitting.
Dated this 5th day of July 1884.
GORHAM GRAY.
I hereby Certify that the above written Signature Gorham Gray is the true and.
genuine Signature of Gorham Gray, acknowledged in my presence at Cowes
this Fifth day of July 1884.
T
T

page_text: "
I GORHAM GRAY at the Office for Patents 323 High Holborn in the County of
Middlesex do hereby declare the nature of this invention for " DIAPHRAGMS
AND ATTACHMENTS FOR TELEPHONIC PURPOSES and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement :—
These diaphragms are similar to ordinary metal diaphragms but are made of
glass as I find glass to be a more prompt, articulate, exact and sensitive reproducer
than any other material known to me. It is in fact a more active agent.
I make my diaphragms whether of glass or not larger or smaller in diameter
according to the requirements of the case; thus for an ordinary earphone a small
diaphragm of a couple of inches or so across is sufficient, but where it is desired
that the sound is to be audible to a whole room or large space without applying
the instrument to the ear or the ear to the instrument I greatly increase the
diameter for instance to eight or ten inches or more.
The shape of the glass diaphragm may vary to suit circumstances as round,
square, oblong & and the thickness may be varied according to the size or shape.
These diaphragms are securely fastened all round or along their edges and are
not left loose or fastened at certain places only.
These diaphragms may be used as transmitters as well as receivers. Should it
be desirable to converse privately and quietly a funnel shaped trumpet may be
used having a cone to cover the diaphragm with another cone connecting with said
cone by a short piping for application to the ear and for receiving by application
over the ear and for hearing by application over the mouth.
The drawing shows a perspective view of the earphone, which is preferably
independent of the receiver but may be placed upon it when required.
One end of the funnel is applied to the ear and the other to the receiving
instrument: it is of course hollow and has a cone A and B at each end with a
straight piece C in the centre by which it may be held and which serves to connect
the cones.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. A diaphragm for telephone uses constructed of glass.
2. The herein described earphone or funnel having a cone A B at each end and a
central connecting part C substantially as and for the purpose specified.