IMPROVEMENTS IN TELEPHONIC APPARATUS
Year: 1882

page_text: LETTERS PATENT to George Lee Anders, and John Benjamin. Henck the
younger, both of Queen Victoria Street in the City of London, for an
Invention of "IMPROVEMENTS IN TELEPHONIC APPARATUS
23
PROVISIONAL SPECIFICATION left by the said George Lee Anders and
John Benjamin Henck the younger at the Office of the Commissioners of
Patents on the 16th December 1882.
.).
GEORGE LEE ANDERS, and JOHN BENJAMIN HENCK the younger both of
Queen Victoria Street in the City of London "IMPROVEMENTS IN TELEPHONIC
APPARATUS."
This Invention relates especially to instruments for use in connection with
static receiving telephones, such as are described in the specification to Letters
Patent granted to William Robert Lake, dated the 29th March 1881 N° 1395, but
it is equally applicable to other forms of static receivers, and partly also to other
electric telephones.
The Invention consists partly in certain improved forms of transmitting
instruments, and these although especially adapted for use with static receivers
are also applicable to other forms of electric telephones. The objects of this
part of the Invention are to produce a transmitting instrument of low resistance
and at the same time not subject to the fault of too easily breaking the circuit,
and these objects are accomplished by combining microphonic instruments on the
same general plan as that which is commonly known as the Reis transmitter with
less sensitive arrangements in which granulated conducting material is the active
element. The harshness due to breaking contact in the microphonic part is
thus avoided by the impossibility of breaking all the multitude of contacts made
by the granulated conductor at the same time.
According to one modification, this instrument consists of a metallic diaphragm
fixed in a horizontal position and carrying at its centre a button of hard carbon
or other suitable conducting material. Upon this button rests another similar one
"

page_text: mounted as in the Reis-transmitter so as to be free to follow the vibrations of the
diaphragm. . There are also a number of thin strips of metal set so as to project
over the diaphragm without touching it, and a quantity of granulated coke or
other suitable conducting material in a granulated form is placed upon the
diaphragm so as to come in contact with the metal strips. The latter are in
metallic connection with the upper button. The instrument is fitted with a
mouth-piece so arranged as to direct the sound waves upwards against the
diaphragm.
According to another modification of the instrument, instead of placing metal
strips above the diaphragm, a portion of the latter is cut out and reunited to the
remainder by a non-conducting material one portion carrying the lower button,
and the other portion being in metallic connection with the upper button.
Granulated coke or other conductor in a granulated form is placed upon the
diaphragm so as to cover both parts.
According to a further modification each part of the electrically divided
diaphragm carries one or more blocks or buttons of hard carbon or other suitable
conductor and another block or blocks are placed loosely upon these so as to make
a microphonic connection between the two parts of the diaphragm, granulated
conducting material being added as before. In this form the two parts of the
diaphragm form the terminals of the system, and the upper block or button is
entirely free.
In the adaptation of the above forms of transmitters to the static receiver we
modify the methods of connection described in the said former specification in the
following manner:.
In order to avoid the necessity of pressing a key when talking we connect the
plates of the receiver or receivers permanently to the ends of the secondary wire
of the induction coil used for transmitting, thus keeping the latter always in
circuit for talking while the receivers are also always in circuit for listening.
We also pass an intermittent battery current through the primary wire of the
induction coil, the receiver or receivers being always connected to the secondary
wire, before using the instruments, for the purpose of giving to the receivers an
initial charge, which is found to increase their sensitiveness,. and therefore the
loudness of the sounds emitted. A compound key is provided so that this charging
is accomplished by the same movement which serves also to pass a signalling
current to the distant station. The current passing to the distant station may
be the same which passes through the primary wire, or there may be two
independent currents passed by simultaneously closing the circuits of two
independent batteries
These arrangements of receivers may also be used in conjunction with other
forms of transmitters than those herein before described

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Lee Anders & John Benjamin Henck the younger in the
Great Seal Patent Office on the 16th June 1883.
:
GEORGE LEE ANDERS and JOHN BENJAMIN. HENCK, the younger both of
Queen Victoria Street, in the City of London "IMPROVEMENTS IN TELEPHONIC
APPARATUS
"
The said Invention relates especially to instruments for use in 'connection with
static receiving telephones, such as are described in the Specification to Letters
Patent granted to William Robert Lake, dated the 29th March 1881 N° 1395 but
it is equally applicable to other forms of static receivers, and partly also to other
electric telephones.
The Invention consists partly in certain improved forms of transmitting instru-
ments, and these although especially adapted for use with static receivers are also
applicable to other forms of electric telephones. The objects of this part of the
Invention are to produce a transmitting instrument of low resistance and at the
same time not subject to the fault of too easily breaking the circuit, and these
objects are accomplished by combining the lever contacts of what is known as the
"Reis transmitter" with less sensitive arrangements in which granulated conducting
material is the active element. The harshness due to breaking contact to which
the ordinary Reis transmitter is liable is thus avoided by the impossibility of
breaking at the same time all the multitude of contacts made by the granulated
conductor
According to one modification the improved instrument consists of a metallic
diaphragm fixed in a horizontal position and carrying at its centre a button of hard
carbon or other suitable conducting material. Upon this button rests another
similar one mounted on a lever as in the Reis transmitter so as to be free to follow
the vibrations of the diaphragm. There are also a number of thin strips of metal
set so as to project over the diaphragm without touching it, and a quantity of
granulated coke, or other suitable conducting material in a granulated form is
placed upon the diaphragm so as to come in contact with the metal strips. The
latter are in metallic connection with the upper button. The instrument is fitted
with a mouth piece so arranged as to direct the sound waves upwards against the
diaphragm.
This modification of the said Invention is illustrated in Figures 1. and 2.
(Sheet. 1.) of the accompanying sheets of drawings which represent respectively a
vertical section and a plan of a transmitter constructed in accordance therewith.
A, is a metallic diaphragm fixed in a horizontal position between two rings B, B¹,
of cork or other suitable material, and carrying at its centre by the intervention of
a metal cup a, a button C, of hard carbon or other suitable conducting materia'.
Upon this button rests another similar one D mounted on a lever D¹ and
fulcrum pins b, which latter enter mercury cups 6¹ carried by a casting H.
E, is a ring which rests on a packing ring F bearing on the cork ring Band
carries a number of thin metal strips G. projecting over the diaphragm without
touching it. A quantity of granulated coke or other suitable conducting material
in a granulated form is placed over the diaphragm A. as shown so as to come in
contact with the metal strips G, G which are in electrical connection with the upper
button D, forming one terminal, whilst the other terminal is, carried by the
diaphragm. The several rings gripping the diaphragm are secured by screws c, to
the casting H attached to a board I and forming therewith the mouth-piece which
is so arranged as to direct the sound waves upwards against the diaphragm.

page_text: According to another modification of the instrument, instead of placing metal
strips above the diaphragm a portion of the latter is cut out and re-united to the
remainder by a non-conducting material one portion carrying the lower button, and
the other portion being in metallic connection with the upper button, mounted as
before mentioned. Granulated coke or other conductor in a granulated form is
placed upon the diaphragm so as to cover both parts.
Figures 3, and 4, (Sheet 1) are respectively a vertical section and a plan illus-
trating one form of this modification.
A, A¹, are the two parts of a divided diaphragm connected together by elastic
non-conducting material d and gripped between cork or cloth rings B, B₁, the
whole being attached by a holding down ring E, and screws c, c, to the mouth
piece H.
The part A¹ which constitutes about three fourths of the diaphragm carries the
lower button C, of hard carbon or other suitable' conducting material and from this
part one terminal is taken, the part A, which is of a quadrantal form, and from
which the other terminal is taken is in metallic connection by means of a lug'd'
and one of the mercury cups 6' with the upper and similar button D which is
mounted on lever D¹ and fulcrum pins 6 the latter entering the mercury cups 61
Granulated coke or other conductor in a granulated form is placed upon the
diaphragm as shown so as to cover both parts.
The diaphragm may be divided down the centre and the lower button with its
upper button and lever contacts be duplicated, one set being applied to each part
of the diaphragm, whereby a similar result is obtained.
This form is illustrated in vertical section in Figure 5. (Sheet 2).
A, A¹, are the two parts of the electrically divided diaphragm, the division being
made at the centre and the two parts connected together by non-conducting
material d. Each part of the diaphragm carries a block C of hard carbon or other
suitable conducting material and upon these rest two similar upper blocks or
buttons D, D, mounted on levers D', D¹, and fulcrum pins b, the latter entering
mercury cups b¹ which are in electrical connection with each other.
Granulated coke or other conductor in a granulated form is placed upon the
diaphragm so as to cover.both parts, as shown.
In this form the two parts of the diaphragm constitute the terminals of the
system as indicated in the drawing. The diaphragm is secured by the aid of a
ring B to the mouth-piece H.
In the adaptation of the above forms of transmitters to the static receiver we
modify the methods of connection described in the said former specification in the
following manner
In order to avoid the necessity of pressing a key when talking we connect the
plates of the receiver or receivers permanently to the ends of the secondary wire of
the induction coil used for the transmitter thus keeping the latter always in circuit
for talking while the receivers are also always in circuit for listening..
We also before using the instrument pass an intermittent battery current through
the primary wire of the induction coil (the receiver or receivers being always
connected to the secondary wire) for the purpose of giving to the receiver or
receivers an initial charge, which is found to increase their sensitiveness and
therefore the loudness of the sounds emitted. A compound key is provided so that
this charging is accomplished by the same movement which serves also to pass a
signalling current to the distant station. The current passing to the distant station
may be the same which passes through the primary wire, or there may be two
independent currents passed by simultaneously closing the circuits of two
independent batteries.
This part of the Invention is illustrated diagrammatically in Figure 6, (Sheet 2)
of the drawings.
A is the induction coil used for the transmitter, 1, the primary wire and 2 the
secondary wire of the said coil, B are the terminals of the receivers; the plates of
which are connected perinauently to the ends of the secondary wire 2, the receivers

page_text: being thus always in circuit for listening whilst the transmitter is always in circuit
for talking. C is the battery used for transmitting and also for giving an initial
charge to the receivers as herein before mentioned. D is the signalling battery,
E the bell mechanism.
a, b, are springs acted upon by a common button c, forming a compound key, by
depressing which and causing the springs to make contacts d, e, the initial charging
of the receivers and the act of signalling to the distant station are simultaneously
accomplished. f, is the hook or support which when the telephone (receiver) F is
suspended thereon as shown, makes the contact ġ, but when the telephone F is
removed therefrom makes the two contacts h, i.
The arrangement of the circuits and the mode of operation will be understood
from an inspection of the diagram with the aid of the following description.
In receiving a signal from the distant station the parts are in the position shown
in the drawings, the springs a, b, being off their contacts d, e, and the spring b
making contact at e¹ and the telephone F on its hook or support f, and the latter
thus making its contact g: The circuit is then from line by wire 3, support f,
contact g, wire 4, to contact e¹ spring b, and wire 5 to bell E and thence by wire 6,
to earth. For the reception of a message the compound key a, b, c, is in the
position indicated in the drawings but the telephone F is off its hook or support f.
The circuit is then from line by wire 3 support f, contact i, wire 2, to receivers B,
then from receivers by wire 2, and wire 6 to earth.
For signalling to the distant. station the button c is depressed bringing the
springs a, b, into contact at d, e the telephone being as shown on its hook or support.
The circuit is then from one pole of battery D by wire 7, to contact e, thence by
wire 5, bell E, wire 6, to earth and from the other pole of battery D by wire 3,
to line.
By the same intermittent movement of the button c, by which a signal is
transmitted to the distant station, the spring a, is brought into contact with d, and
the circuit of the primary wire 1, containing the battery C is completed whereby a
current is induced in the secondary wire 2 and the receivers B receive an initial
charge. The circuit is from battery C to coil A by wire 1, then to contacts a, d,
thence by wire 3 back to battery
For the transmission of a message the compound key a, b, c, is in the position
indicated in the drawing but the telephone F is off its hook or support f. The
local circuit is then from battery C to coil A by wire 1, thence by wire 8 through
transmitter T to contact h, and thence by support f, and wire 3, back to battery.
The main circuit is from line by wire 3, support f contact i wire 2, through
induction coil and then by wire 6 to earth.
The arrangements of receivers forming the subject of this part of the said
Invention may also be used in conjunction with other forms of transmitters than
those herein before described.
Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or carried into
effect we would observe in conclusion that what we consider to be novel and original
and therefore claim as the invention secured to us by the hereinbefore in part
recited Letters Patent is:-
First. The combination in telephonic transmitting apparatus with contacts
herein designated "Reis lever contacts " of conducting material in a granulated
form substantially as and for the purpose herein before described.
Second. In telephonic transmitting apparatus of the type bereinbefore referred
to, the combination of a horizontal metallic diaphragm carrying a lower button of
conducting material, an upper button of conductiug material mounted on a lever
so as to rest on the lower button, metallic strips in electrical connection with the
upper button, and conducting material in a granulated form, constituting an
electrical continuity between the metallic diaphragm and the metallic strips, and
thence with the upper button all substantially as hereinbefore described.
Third. In telephonic transmitting apparatus of the type hereinbefore referred to,

page_text: the combination of an electrically divided metallic diaphragm, a lower button of
conducting material carried by one portion of such diaphragm, an upper button of
conducting material mounted on a lever so as to rest on the said lower button, and
in electrical connection with the other portion of such electrically divided diaphragm;
and granulated conducting material forming electrical continuity between the two
portions of the said diaphragm all substantially as herein before described.
Fourth In static receiving telephones the connecting of the plates of the receiver
or receivers permanently to the ends of the secondary wire of the induction coil
used for transmitting, substantially as and for the purpose hereinbefore described.
Fifth. In static receiving telephones having the plates of the receiver or receivers
permanently connected to the ends of the secondary wire of the induction coil, the
employment of means whereby an intermittent battery current is passed through
the primary wire of the induction coil before using the instruments, for the purpose
of giving to the receiver or receivers an initial charge, substantially as hereinbefore
described
.
Sixth. In static receiving telephones arranged as set forth in the preceding
claiming clause, the employment of a compound key so arranged that the initial
charging of the receiver or receivers is accomplished by the same movement as
serves also to pass a signalling current to the distant station, substantially as
bereinbefore described.
'
In witness whereof we the said George Lee Anders, and John Benjamin
Henck the younger have hereunto set our hands and seals this fifteenth
day of June in the year of our Lord one thousand eight hundred and
eighty three.