Improvements in Telephonic Apparatus,
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Telephonic Apparatus,
I, ALFRED GRAHAM, of 32, Crespigny Park, Denmark Hill, in the County of
London, Electrician, do. hereby declare the nature of this invention to be as
follows:-
This invention has reference to improvements in telephonic apparatus whereby
I am enabled to provide a loud talking apparatus of simple construction and such
as can be used in positions where it will be exposed to damp air, storms and rough
usage without liability of its efficiency being thereby interfered with.
According to one construction, the apparatus comprises a vertical metal base
or support to which is secured, as by screws, a hollow metal cover, the base and
cover forming a casing adapted to enclose the transmitter, receiver and other parts
of the apparatus. In order that water or moist air shall not enter the trans-
mitter and interfere with its efficiency, the tension regulator of such transmitter
is enclosed in a water tight case provided with a movable side or diaphragm
adapted to transmit vibrations of the external atmosphere to the said tension
regulator. A construction of transmitter suitable for this purpose comprises a
circular block of insulating material such as vulcanized fibre, made plane at its
rear side and with a recess in its front side in which is placed a carbon cup that
is moulded with a flange and is adapted to hold carbon powder. The carbon cup
is in electrical connection with a metal ring by which it is held in the recess
and which is electrically connected to an external plate of metal by screws the
heads of which terminate within holes in the said plate. The outer ends of these
holes are sealed by material such as solder, so as to obviate any liability of mois-
To the block is secured, as by
ture entering the transmitter along the screws.
a
screws, a metal ring, preferably made as a cap piece of L section, (hereinafter
called for distinction the cap ring) a layer of insulating adhesive material, for
example shellac varnish being preferably applied between the two to ensure a
water-tight joint between them. Over the open end of the carbon cup is placed
its
on
outer side
thin carbon disc or diaphragm which is covered
with a disc of metal foil, such as copper foil, the two discs being clamped
at their periphery between the cap ring and a second metal ring. This second
ring is secured to the cap ring by screws the heads of which terminate within holes
that are formed in the second ring and the outer ends of which are sealed, as by
solder, for the purpose hereinbefore mentioned. The outer peripheries of the
two rings, and the inner periphery of the second ring and the adjacent part of
the disc of metal foil, are soldered together to insure water tight joints between
these parts at the places mentioned. The interior of the transmitter case may,
for a like purpose, be coated with a layer of waterproof material, for example
shellac varnish.
To enable the telephone transmitter to successfully withstand shocks such as

page_text: it is liable to receive on board a war ship, the carbon cup may be seated upon
cushioning material, which may conveniently consist of several layers of paper and
one or more layers of cotton lint, wool or felt; or metal springs may be used. Also
between the edge of the carbon cup and the carbon disc there is preferably placed
a ring of soft material, such as cotton lint, wool, or felt that is held in place
by a rigid ring, the inner edge of the ring of soft material being caused
to bear against the said carbon disc so as to prevent escape of the carbon powder.
This carbon power should only partly fill the space between the carbon cup
and carbon disc. Fixed to the transmitter but insulated therefrom, as by a ring
of vulcanized fibre of L section, is a metal ring formed with a hollow extension.
Fixed to this hollow extension is a ring formed with a flaring mouth piece and
provided with a handle and knob. A perforated or reticulated metal plate is
clamped between the hollow extension and a conical distance piece of insulating
material, the said plate being arranged opposite the carbon and metal discs so as
to protect the same.
The transmitter is mounted so as to be capable of being rotated, for example
through about half a rotation, by means of the handle in order to shake up the
carbon powder each time the apparatus is used, and also to make and break
certain connections, as will be hereinafter described the motion in each direction
being limited by stops. For this purpose the aforesaid hollow extension is
mounted to turn in the forward portion of a bracket fixed to the base or support
and also in a corresponding opening in the cover. The back of the transmitter
is connected through a block of insulating material to the flanged end of a
spindle the other end of which is journalled in the back part of the said bracket.
A coiled spring encircles the spindle one end of such spring being fixed to the bracket
and at the other end to a lug on the spindle. This spring acts to automatically
return the transmitter, operating handle and attached parts back into the starting
position after being moved therefrom.
The telephonic receiver is of the magneto-electric type and comprises a diaphragm
held in position by a frame, and a permanent magnet that is of approximately
semi-annular form, and has its free ends bent radially inward and towards one
another these ends being provided with polar extensions which terminate in
proximity to the receiver diaphragm and are provided with wire coils of low
resistance. The diaphragm frame is carried in a horizontal position by arms, and
from its lower side a tubular extension projects in a downward and forward
direction so that any water entering it can readily drain away. Over the lower
free end of the said tubular extension slips a horizontally arranged trumpet
shaned part that is made in one piece with or carried by the cover of the apparatus.
The switch controlling the circuits of the apparatus comprises two spring con-
tacts I will call A and B fixed to the metal holders carried by the aforesaid bracket
but insulated therefrom by a block of insulating material. Upon the opposite
side of the bracket are two fixed contacts I will call C and D that are insulated
from the said support by another block of insulating material. The contact
is connected by a conductor to one terminal of an electric bell the other terminal
of which is connected to earth. The contact D is connected to one end of the
receiver coils the other end of which is connected to earth. An insulated stop
is provided for the spring contact A. Carried by but insulated from the bracket
is a metal piece connected on the one side to the back plate of the transmitter
through a coiled wire and on the other side to one pole of a battery the other
pole of which is connected to earth. To the spindle but insulated therefrom are
fixed two contact pieces I will call E and F that are respectively connected by
electric conductors with the aforesaid cap ring and the back plate of the trans-
mitter and constitute the terminals of such transmitter which is thus completely
insulated. By this means the metal casing of the apparatus and the metal of the
ship on which the apparatus is used, or earth, can be used for the common return
circuit of the apparatus instead of a separate wire. The spring contact A is con-
nected through its bearing piece or holder to a line wire extending to another
similar instrument. The spring contact B is connected through its bearing

page_text: piece or holder to another line wire and is arranged to be lifted from off the
fixed contact C and into connection with the fixed contact D by an insulated
cam piece on the spindle when the latter is turned through about 180 degrees.
To prevent wear of the spring contacts A and B each of them may be provided
with a renewable wearing piece.
..
The arrangement is such that when the transmitter is in the off" position,
the transmitter terminals E and I are in the inoperative positions and the spring
contact B is resting on the fixed bell contact C and upon partly turning the trans-
mitter in one direction, the insulated terminals F and E are brought successively
into connection with the spring contact A so that the corresponding line wire is
placed in connection with the battery first directly, and afterwards indirectly
through the transmitter, the cam piece on the spindle finally moving the spring
contact B from the fixed contact Ċ to the fixed contact D. The four conductors
are led out of the casing through a suitable hole formed in the base, and in a
cover plate or gland.
""
Two apparatus or instruments of the kind herein before described are adapted
for use by connecting the line wire that extends from the transmitter spring
contact A of one instrument to the bell and receiver spring contact B of the
other instrument, and the line wire that extends from the bell and receiver
contact B of the first mentioned instrument to the transmitter contact A of the
other instrument. When the transmitters are in the "off" position, the trans-
mitter, receiver and bell of each instrument are disconnected from the battery.
Upon turning the transmitter of either instrument from the "off" to the on
position, the spring contact A of such instrument will be placed in connection
with the battery, first directly, and afterwards through the transmitter, and a
current will be sent along the corresponding line wire to the bell of the second
instrument which will continue to ring until the transmitter of such second
instrument has been moved into the on position. When this has been done
both bells will be out of circuit and the transmitter and receiver of both instru-
ments in circuit so that telephonic messages can be sent from one to the other
through the two complete and independent circuits, each of which includes a
transmitter and a receiver. As will be understood, the construction is such that
a separate calling key is dispensed with.
"
As will be obvious the switch connections can be variously modified, if desired.
Dated this 2nd day of September 1898
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.
I, ALFRED GRAHAM, of 32, Crespigny Park, Denmark Hill, in the County of
London, Electrician, 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 :-
-
This invention has reference to improvements in telephonic apparatus whereby
I am enabled to provide a loud talking apparatus of simple construction and such
as can be used in positions where it will be exposed to damp air, storms and
rough usage without liability of its efficiency being thereby interfered with.
For this purpose my improved telephonic apparatus is constructed as I shall
now describe with reference to the accompanying illustrative drawings wherein

page_text: Figs. 1 and 2 are respectively a front elevation and a vertical longitudinal section
showing my improved apparatus. Fig. 3 is a front elevation partly in section, with
the front cover and the transmitter removed. Fig. 4 is a horizontal section
partly on the line A A and partly on the line B B of Fig. 2. Fig. 5 is an inverted
section on the line A. A of Fig. 2, with the cover of the apparatus removed, and
showing the receiver and its support. Fig. 6 is an underside view of the metal
base or support that carries the various parts of the apparatus. Figs. 7 and 8
are detail views. Figs. 9 and 10 are diagrams.
1 is a metal base or support to which is secured, as by screws 2, a hollow metal
cover 3, preferably of iron, the base and cover forming a complete iron or metal
casing adapted to enclose the microphone transmitter, receiver and other parts
of the apparatus. In order that water or moist air shall not enter the transmitter
and interfere with its efficiency, such transmitter is enclosed in a water tight case
provided with a movable side or diaphragm adapted to transmit vibrations of the
external atmosphere to the said transmitter. The construction of microphone
transmitter for this purpose shown in Fig. 2, comprises a circular block 4 of
insulating material such as vulcanized fibre, made plane at its rear side and with
a recess 4 in its front side in which is placed a carbon cup 5 moulded with a
flange 5 and adapted to hold carbon powder 6. The carbon cup 5 is in electrical
connection with a metal ring 7 by which it is held in the recess 4" and which is
electrically connected to an external metal plate 8 by screws 9 the heads of which
terminate, as shown, within holes in the said plate. The outer ends of these
holes are scaled by material 10 such as solder, so as to obviate any liability of
moisture entering the transmitter along the screws 9. To the block 4 is secured,
as by screws 11, a metal ring 12, preferably made (as shown) as a cap piece of
L section, a layer of insulating adhesive material, for example shellac varnish,
being preferably applied between the two to ensure a water-tight joint between
them. Over the open end of the carbon cup 5 is placed a thin carbon disc or
diaphragm 13 which is covered on its outer side with a disc 13" of metal foil,
such as copper foil, the two discs being clamped at their periphery between the
metal ring 12 and a second metal ring 14. This second ring 14 is secured to the
ring 12 by screws 15 the heads of which terminate within holes that are formed
in the ring 14 and the outer ends of which are sealed, as by solder 16, for the
purpose herein before mentioned. The outer peripheries of the two rings 12
and 14, and the inner periphery of the second ring 14 and the adjacent part of the
disc of metal foil 13" are soldered together as shown at 17 and 17" respectively
to insure water tight joints between these parts at the places mentioned. The
interior of the transmitter case may, for a like purpose, be coated with a layer of
waterproof material, for example shellac varnish.
To enable the telephone transmitter to successfully withstand shocks such as
it is liable to receive on board a war ship, the carbon cup 5 is or may be seated
upon cushioning material 18, which may conveniently consist of several layers
of paper and one or more layers of cotton lint, wool or felt; or metal springs
may be used.
Also between the edge of the carbon cup 5 and the carbon disc 13
there is preferably placed a ring 19 of soft material, such as cotton lint, wool, or
felt that is held in place by a rigid ring 19ª, and the inner edge of which ring 19
is caused to bear against the said disc 13 so as to prevent escape from the carbon
cup of the carbon powder 6 which should only partly fill the space between the
carbon cup 5 and disc 13. As will be seen the above described construction of
water proof transmitter is similar to that described in the Specification of my
former l'atent No. 591 of 1898.
The transmitter, according to the present invention, is mounted and operated
as follows: 20 is a metal ring fixed to the transmitter but insulated therefrom
as by a ring 21 of suitable insulating material for example vulcanized fibre of
Lsection. Fixed to a hollow extension 20" of the ring 20 is a ring 22 formed
with a flaring mouth piece and provided with a handle 22" and knob 22b. 23 is
a perforated or reticulated metal plate clamped between the extension 20" and a

page_text: hollow conical distance piece 20b of insulating material and arranged opposite
the carbon and metal discs 13, 13 so as to protect the same.
The transmitter is mounted so as to be capable of being rotated, for example
through about half a rotation in the construction shown, by means of the
handle 22 in order to shake up the carbon powder 6 each time the apparatus is
used and also to make and break certain connections, as will be hereinafter
described, the motion in each direction being limited by stops 3. For this
purpose the hollow extension 20 of the ring 20 is mounted to turn in the forward
portion 23" of a bracket 23 fixed to the base 1, and also in a corresponding opening
in the cover 3. The back of the transmitter is connected through a block 8*
of insulating material to the flanged end 24" of a spindle 24 the other end of
which is journalled in the back part of the bracket 23. 24b is a coiled spring
encircling the spindle 24 and fixed at one end to the bracket and at the other
end to a lug 24 on the spindle. This spring acts to automatically return the
transmitter, operating handle 22, and attached parts into the position shown in
Fig. 1 after being moved from this position. A coiled spring otherwise arranged
may be used for the same purpose.
The telephone receiver is of the magneto-electric type and comprises a
diaphragm 25 held in position by a frame 26, and a permanent magnet 27 that
is of approximately semi-annular form, (Fig. 5) and has its free ends 27" bent
radially inward and towards one another and provided with polar extensions 27
which terminate in proximity to the receiver diaphragm 25 and are provided
with wire coils 28 of low resistance. The diaphragm frame 26 is carried in a
horizontal position by arms 1" and from its lower side a tubular extension 26"
projects in a downward and forward direction so that any water entering it can
readily drain away.
Over the lower free end of the extension 26 slips a hori-
zontally arranged trumpet shaped part 3 made in one piece with the cover 3.
The switch controlling the circuits of the apparatus comprises, in the example
shown, two spring contacts 29 and 30 fixed to metal holders 29" and 30" respec-
tively carried by the bracket 23 (Fig. 4) but insulated therefrom by a block 31
of insulating material. Upon the opposite side of the bracket 23 are two fixed
contacts 32 and 33 (Figs. 4 and 7) that are insulated from the said support by
another block 31" of insulating material. The contact 32 is connected by a con-
ductor 32 to one terminal of an electric bell 34 (Figs. 9 and 10) the other terminal
of which is connected to earth E. The contact 33 is connected to one end of the
receiver coils 28 the other end of which is connected to earth E. 29* is an insu-
lated stop for the spring contact 29. 35 (Figs. 4, 9 and 10) is a metal piece carried
by but insulated from the bracket 23 and connected on the one side to the plate 8
of the transmitter through a coiled wire 35" and on the other side by a wire 35
to one pole of a battery 35° the other pole of which is connected to carth E. To
the spindle 24, but insulated therefrom, are fixed two contact pieces 29 and 29°
that are respectively connected by electric conductors 12" and 8" (Fig. 2) with the
ring 12 and plate 8 of the transmitter and constitute the terminals of such trans-
mitter which is thus completely insulated. By this means the metal casing of
the apparatus and the metal of the ship on which the apparatus is used, or earth,
can be used for the common return circuit of the apparatus instead of a separate
wire. The spring contact 29 is connected through its bearing piece 29" to a line
wire 36 extending to another instrument as shown at the left hand side of
Figs. 9 and 10.
The spring contact 30 is connected through its bearing piece 30°
to another line wire 37 and is arranged to be lifted from off the fixed contact 32
and into connection with the fixed contact 33 by an insulated cam piece 38
(Fig. 2) on the spindle 24 when the latter is turned through about 180 degrees.
To prevent wear of the spring contacts 29 and 30 each of them may be provided
with a renewable wearing piece 39 (Fig. 3).
As will be seen the switching arrangement is such that when the transmitter
is in the "off" position shown in Figs. 1, 3 and 9, the transmitter terminals 29b
and 29 are in the inoperative positions shown in Figs. 3 and 9 and the spring con-
tact 30 is resting on the fixed bell contact 32, and upon partly turning the

page_text: transmitter in the direction of the arrow (Fig. 9), the insulated terminals 29å
and 29 are brought successively into connection with the spring contact 29 so
that the line wire 36 is placed in connection with the battery 35b first directly,
and afterwards indirectly through the transmitter, the cam piece 38 finally
moving the spring contact 30 from the fixed contact 32 to the fixed contact 33.
The four conductors 32", 35, 36 and 37 are led out of the casing 3 through a suit-
able hole 39 formed in the base 1, and in a cover plate or gland 40 (Figs. 3 and 6).
Two apparatus or instruments of the kind described are adapted for use by con-
necting the line wire 36 that extends from the transmitter spring contact 29 of one
instrument to the bell and receiver spring contact 30 of the other instrument, and
the line wire 37 that extends from the bell and receiver contact 30 of the first men-
tioned instrument to the transmitter contact 29 of the other instrument, as shown in
Figs. 9 and 10. Fig. 9 shows the positions of the various parts when the trans-
mitter handle 22 of each instrument is in the "off" position, and Fig. 10 shows
the positions of the parts when the transmitter handle of each apparatus has been
fully turned into the on" position. In the former case (Fig. 9) the transmitter,
receiver and bell of each instrument are disconnected from the battery 35. Upon
turning the transmitter of either instrument from the "off" to the
on position,
the spring contact 29 of such instrument will be placed in connection with the
battery first through the conductor 8" and metal piece 35 and afterwards through
the conductor 12" and transmitter and metal piece 35, and a current will be sent
along line 36 or 37 to the bell 34 of the second instrument which will continue
to ring until the transmitter of such second instrument has been moved into the
position. When this has been done (Fig. 10), both bells will be out of
circuit and the transmitter and receiver of both instruments in circuit so that
telephonic messages can be sent from one to the other through the two complete
and independent circuits, each of which includes a transmitter and a receiver.
As will be seen the construction is such that a separate calling key is dispensed
with.
"
on
"
"
6
""
The switch connections can be variously modified, if desired, without interfering
with the general arrangement of the apparatus. Thus the normal position of the
handle 22 may be vertical and below the mouth piece of the transmitter, and the
switch connections be such that the handle must be turned to one side for ringing
and to the other side for speaking.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is
1. Telephonic apparatus comprising a microphone transmitter made water-
proof and adapted to be rotated about a horizontal axis, a magneto-electric receiver
having its diaphragm held in a horizontally arranged holder that communicates
with a horizontally arranged flaring part by means of a tubular extension that
projects downward and forward from the holder so that water can readily drain
away from the holder, and switch connections arranged to be operated when the
transmitter is operated, substantially as herein described for the purposes set forth.
2. Telephonic apparatus wherein the rotary microphone transmitter of each of
two connected instruments is provided with insulated terminals so arranged in
relation to the switch connections of such instrument that when the transmitter
of either instrument is moved from its normal position whilst the transmitter of
the other instrument is in the "off" position, the call bell of the second instru-
ment will be rung by an electric current that passes from a battery to the line
wire first independently of the transmitter of the first instrument and afterwards
through such transmitter when the same is in the "
ment of the transmitter serves not only to ring the call bell of the second instru-
on" position, whereby move-
ment, but also to shake up the carbon powder in the transmitter, substantially
as described.
3. The combination and arrangement of parts constituting my improved tele-

page_text: phonic apparatus substantially as hereinbefore described with reference to and
shown in the drawings annexed.
THIS KI
day or June 1899.
For the Applicant,
W. LLOYD WISE,
4G, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.