Year: 1887

page_text: Date of Application, 3rd Sept., 1887
Complete Left, 4th June, 1888
Complete Accepted, 6th July, 1888
We JOHN SAMUEL ROSS and HENRY BAINES both of 72 Hammersmith Road West
Kensington in the County of Middlesex Electricians do hereby declare the nature of
this invention to be as follows:-
Diaphragms may be caused to avoid affections from damp & other atmospheric
changes by combination preferably on their outsides of thin sheets or tissues of india-
rubber or gutta-percha or the like substances. These substances may also be applied
in the forms of solutions which as evaporation takes place leaves the substances coated
on the diaphragms. A diaphragm may be caused to avoid the danger of being drawn
on to its magnet when in use by having a piece of metal or other substance attached
to its centre preferably. The said piece is made exceedingly flexible & is only strong
and does not give when pulled in the direction of its length. The other end of this
piece is attached to a small arm, bracket or crosspiece fixed to the diaphragm or the
case of the instrument or other desirable place. The length of this piece can be
mechanically regulated and will usually tho not necessarily take a slightly curved
form. By proper adjustment of this piece the diaphragm would always be prevented
from adhering to the magnet or magnets. Adherence of a diaphragm to a magnet
may also be avoided by arranging a circuit so that whenever the diaphragm or arma-
ture touches the magnet the magnetising coil is thereby cut out or only remains as a
high resistance shunt. The diaphragm or armature then keeps going backwards &
forwards & by making a noise causes it to be known which telephone requires
adjustment. Some diaphragms, particularly a Bell diaphragm, give out notes when
spoken to which cause the speech to be somewhat blurred & indistinct. This defect
can be overcome by combining with the diaphragm on one or both sides a sheet or
tissuee of india-rubber or gutta-percha or the like substances or by covering the
diaphragms with these substances in the forms of solutions which when evaporation
occurs leaves a coating on the diaphragms & so greatly damp the notes that would
otherwise be given out.

page_text: We JOHN SAMUEL ROSS and HENRY BAINES both of 72 Hammersmith, Road West
Kensington in the County of Middlesex Electricians do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
We discard any claim to the use of solutions of india rubber or gutta percha for
coating the surfaces of electrical diaphragms but confine ourselves to the use of sheets
or tissues of india-rubber or gutta-percha which may be attached to the surfaces or
interior of a diaphragm in any way most convenient.
The acoustic properties of a Bell diaphragm may by this means be greatly improved.
We also discard the method mentioned in our provisional specification for avoiding
the danger of a diaphragm being drawn on to its magnet by having one end of a piece
of flexible substance attached to its centre the other end being attached to a small arm,
bracket or crosspiece fixed to the case, excepting in so far as that method may be
covered by patent numbered 13569 and dated October 23. 1886.
The adherence of a diaphragm to a magnet may be avoided by arranging an
electrical circuit so that should the diaphragm be ever drawn on to its magnet, the
magnetizing coil is thereby cut out momentarily or only, remains as a high resistance
shunt. The diaphragm will then keep vibrating and by making a noise and with the
use of an indicator or bell attention will be drawn to the fact that the telephone
requires adjustment. Or should the diaphragm be ever drawn on to its magnet and
touch same, may thereby be also caused to complete a local circuit which will ring a
bell or drop the flag of an indicator informing which telephone requires adjustment.
Having now particularly described the nature of our said invention & in what
manner the same is to be performed we declare that what we claim is :
1. In a telephonic instrument the combination of a diaphragm with sheet or sheets,
tissue or tissues of india-rubber or of gutta-percha.
2. In a telephonic instrument the use of the diaphragın or magnet or magnets in
any way for automatically informing when a telephone requires adjustment.
Dated this 4th day of June 1888.