IMPROVEMENTS IN CALL OR SIGNALLING APPARATUS EMPLOYED IN CONNECTION WITH TELE- PHONES
Year: 1879

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS IN
CALL OR SIGNALLING APPARATUS EMPLOYED IN CONNECTION WITH TELE-
PHONES. A communication from abroad by Clément Ader, of Paris, in the
Republic of France.
"
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 30th September 1879.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN CALL OR SIGNALLING APPARATUS EMPLOYED IN
CONNECTION WITH TELEPHONES." A communication from abroad by Clément Ader,
of Paris, in the Republic of France.
This Invention relates to apparatus to be interposed in the circuit of the wires of
transmission of telephones for the purpose of calling the attention of persons at the
receiving telephone, when a message is about to be transmitted. The apparatus
which do not require a battery, may be arranged near the telephones or directly
combined with them.
When it is not required to make the apparatus an integral part of the telephone,
it is proposed to construct it in the following manner :-
A box is provided carrying binding screws or terminals, to which are connected
the wires of the circuit. This box is furnished with a glazed or other opening,
behind which is arranged a button or other object of a distinctive character or color,
and which is capable of being brought opposite the opening, so as to be visible, or
moved away from it. This button or signalling device is carried by one arm of a
double armed lever mounted on a centre or fulcrum, the other arm of which lever
carries an adjustable counterweight. A permanent magnet of a C shape is also
provided, which is suitably supported, and has attached to its ends or poles, angle
pieces which form the magnetic cores of induction coils. Opposite the ends of the
cores which pass through the coils, is situate the free extremity of a thin flexible
blade, the other end of which is rigidly supported; this blade is formed with an

page_text: opening with which is capable of engaging the inclined and bent or hook shaped
end of a vertical bar jointed to the lever at a point intermediate between its
signalling button or device and its fulcrum, the catch or extremity of the bar being
inserted in the opening in the blade by hand; and when so inserted, overcoming the
force of the counterweight and maintaining the signalling button or device in the
requisite position, relatively to the opening in the box.
Assuming one of these apparatus to be arranged in the circuit near a receiving
telephone for example, and the wires of the induction coils to be suitably connected
when a blow is given on the mouthpiece of the transmitting telephone, or a vocal
sound is directed into the mouth piece, the blade before mentioned commences to
vibrate in front of the induction coils, and the vibration acting with increasing
intensity, the inclined catch is gradually moved and ultimately released from its
opening, thus allowing the lever to descend, and bringing the signalling device or
button into the position to give the required visible signal. The apparatus then
remains in this position until the catch is reinserted by hand in the opening
in the vibrating blade.
In applying the call or signalling apparatus in combination with telephones, such
for example, as the telephones in respect of which Letters Patent were granted to
me, dated the 30th January 1879, No. 394, the vibrating plate or diaphragm of the
telephone is also utilized to perform the functions of the vibrating blade before
referred to, and which in that case is dispensed with, the diaphragm being provided
with an opening with which engages tho catch for controlling the call or signalling
apparatus. The catch is jointed to the end of a horizontal arm of a vertical bar of
an elongated section, which is guided so as to be capable of rising and falling; the
vertical bar being suitably weighted in a similar manner to the lever of the
preceding modification.
When therefore the diaphragm of the telephone is set in vibration the catch is
acted upon and ultimately released, thus allowing of the descent of the weighted
bar and bringing into view a portion of the bar which is painted or otherwise
prepared so as to form the visible signal, the apparatus then remaining in this
position until the catch is replaced by hand.
It is obvious that the converse of the arrangements hereinbefore described inay
be adopted, that is to say, the incline may be provided on the vibrating blade or
diaphragm, and the engaging catch picce may be formed with the requisite
opening.
The apparatus may also be put into gear after each disengagement, automatically
if desired, and springs or other equivalent mechanical contrivances may be
substituted for the counter-weights, and the release of the catch may further be
caused to actuate an electric or other bell, or give any other suitable audible signal.
When pneumatic signals (such as are described in the Specification to Letters
Pateut granted me, dated the 3rd October 1878, No. 3892) are employed in com-
bination with the visble signals hereinbefore referred to, it is desirable that
synchronism should be established between the vibrations of the reed of the pneumatic
signal and the vibrations of the blade or plate of the visible signal.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 24th
March 1880.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN CALL OR SIGNALLING APPARATUS EMPLOYED IN
CONNECTION WITH TELEPHONES." A communication from abroad by Clément Ader,
of Paris, in the Republic of France.
The signals, such as electric bells, annunciator-discs, and the like commonly used
in connection with telephones require for operation a current of considerable tension
or strength, which is furnished by a battery or magneto-electric machine of sufficient
power. Moreover, for signals heretofore known, or at least for all visible signals,
electro-magnets and armatures independent of the bobbins and diaphragm of the
receiving telephone are necessary.
This Invention relates to a visible signal capablo of operation without a battery
or special magneto-machine by means of feeble currents, such as may be generated
by the vibratory plate or diaphragm of a telophone of ordinary or suitable construc-
tion. Instead of requiring an independent electro-magnet and armature it is adapted
to be connected with and operated by the diaphragm of a telephone, but instruments
independent of the telephones and connected in the circuit in the ordinary manner
may be employed.
A disc or other device is connected with a vibratory plate or strip, and adapted
to be operated by successive vibrations of the said plate or strip, of which no one
vibration would produce that effect. The connection with the plate or strip is made
by a catch or jointed arm which retains the disc in position by engagement with
the plate or strip. When the catch is released the disc or other device moves under
the influence of a weight or spring or similar power. An inclined plane on the catch
or vibratory plate is the means in connection with the weight or spring for causing
the effective operation of the vibrations to be in one direction, that is, in a direction
to disengage and release the catch.
And in order that the 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 is an isometrical perspective view of an
apparatus constructed in accordance with the said Invention.
Figure 2 is a similar view drawn to an enlarged scale of the mechanism contained
in the outer case of the apparatus shown in Figure 1, and Figure 3 is a view in
section of a telephone having combined with the diaphragm thereof the signalling
apparatus which forms the subject of the said Invention. Figures 4 and 5 are details
which will be hereinafter referred to.
A, Figure 1, represents a box or case the back of which, being prolonged at the
top and bottom, serves for fixing it against a wall, for example, and for carrying at
the same time the binding posts a, a, to which the wires of the telephone circuit
are attached. In the face of this box is an aperture a² for observing the signal
device, which is or may be a white disc, and in the side is a slot (not shewn)
through which the lever B projects. The lever B carries on its projecting end an
adjustable counterpoise b. It is bent as shewn in Figure 2, and is pivotted to the
support fixed to the back of the box A. At the end opposite the counterpoise b
is a white signal disc b*, and at a point intermediate the arm or catch b³ is jointed
thereto.
C is a curved magnet held in position by means of cross pieces c and the nuts c¹.
Upon the poles of this magnet are mounted the right angled pieces c” which form
the magnetic cores of the bobbins c³.

page_text: D is a vibratory strip or plate in which is an aperture d. In Figure 2 this strip,
as shown, is very thin and flexible. It is secured at one end by the cross piece d³
to the right-angled piece d', so that its free end extends across the ends of the cores
of the bobbins in close proximity thereto. The picce d' is secured to the back of
the case.
The jointed arm or catch b at its free end is bent as shown, and presents from b
to be a plane slightly inclined with reference to that of the aperture d, into which
latter it projects as shown when the lever B is in proper position for operation.
In applying the apparatus shown in Figures 1 and 2, and herein before described,
one apparatus is located at the transmitting and one at the receiving station; they
are placed near the telephones or combined therewith, and connected in the circuit
in any ordinary or suitable manner. The counterpoise is adjusted so that it tends
to lift the disc b², and the lever B is raised by means of the end projecting from the
case until the end of the catch b³ engages in the aperture in the vibratory plate
or strip D. The disc b² then appears through its opening a, Figure 1.
In order to cause a signal to be made a strong blow with the hand is given on
the mouth piece of the telephone at the calling station (this has been practically
demonstrated to be sufficient), or a call is shouted in the same mouth piece in a high
key. The strip D is thrown in vibration by means of currents passing through the
coils of the bobbins c³, and at each vibration the inclined plane b, ³, moves out-
ward a short distance from the upper edge of the aperture d until it escapes
altogether from the said edge, and the lever B being released the disc b, under the
action of the counterpoise b, disappears from behind the opening a. The lever B
is brought to rest by contact of the bent portion thereof with the upper cross-piece
c, which is cut away at c' for that purpose.
In order to set the apparatus for another signal the projecting end of the lever B
is raised as before described.
Particular attention is called to the following point, which constitutes the leading
fenture in the said Invention. It is, that the bent end of the catch or arm 6ª, in
operating as before described, moving in one direction without the possibility of
returning in the opposite direction, is only released from the aperture d by the
accumulation of a series of small actions resulting from the vibrations of the strip D,
and the disengagement is more rapid as the rapidity of the vibrations increases.
Without entering into theoretical considerations, which would be here out of
place, I would remark that the arm b³ is acted upon during the vibrations of the
strip D by a mechanical force tending to draw it away, and due to the counter-
weight and second, by the magneto-electro force changing in polarity at each
movement which produces the vibrations of the strip or plate D.
i
During a half vibration the vibratory strip or plate will carry with it the catch
63. During another half vibration, the complement of the first, the catch will not
be affected, and the counterpoise b which tends to draw it away will keep it in the
position already acquired, and so on for each vibration.
I will now describe the arrangement preferably adopted in applying the signalling
apparatus to a telephone, reference being had to Figure 3 of the Drawings. The
telephone shown is that known as the chronometer telephone," the Invention of
F. A. Gower and Roosevelt, in respect of which Letters Patent were granted to me,
dated January Thirtieth, One thousand eight hundred and seventy nine, No. 394,
but one of any ordinary or suitable construction may be used in place thereof. It
is represented as suspended against the wall by a ring fixed to the telephone
frame. In this case the vibratory plate D is replaced by the diaphragm of the tele-
phone itself.
The arm or catch 63, the end of which engages with the aperture d, is jointed at
its upper end to the horizontal arin e fixed to the sliding plate or rod E, which is
guided in its up and down movements by the piece e', and which take the place of
the counterweighted lever before described. A stop or projection et limits the move-
ment downward of the plate or rod E.
The several parts having been arranged as shown in the Figure, if the vibratory

page_text: plate or diaphragm D be thrown into vibration by currents in the coils of the tele-
phone, the arm or catch 63 will be acted upon by a mechanical force tending to make
it descend, and due to the weight of the piece E, and by a magneto-electrical force
which produces the vibrations of the diaphragm or vibratory plate alternately in
opposite directions.
It should be here observed that on account of the difference of direction of the
mechanical force from that in the arrangement first hereinbefore described the
inclined plane is placed on the opposite side of the arm or catch b³ to that repre-
sented in Figure 2.
It will be readily understood from the description herein before given in what
manner the catch 63 will ultimately be disengaged from the opening d, and together
with the piece E will fall until the stop e comes into contact with the upper end of
the piece e¹.
As the piece E descends, its lower end, which may be painted white (for example),
will project below the piece e¹, as shown in dotted lines, and thus furuish the visible
signal desired. In order to reset the device it is sufficient to lift the piece until the
catcli bs engages in the aperture d.
Many modifications may be made in carrying the Invention into effect without
departing from its principle; for example, a drop, as shown in Figure 3, may be
used in connection with an apparatus in other respects similar to that shewn in
Figures 1 and 2, and a counterpoised lever with a catch may be used in combination
with a telephone diaphragın; also, the vibratory plate or strip may be arranged to
carry the inclined plane in place of an aperture, this latter being conversely placed
on the said arm or catch. In lieu moreover of setting the signal by hand, the
inclined plane may be caused to engage with the opening by means of a system of
returning apparatus of any ordinary or suitable construction. In like manner the
weights or counterpoises may be replaced by springs, and also the lever B or piece
E may, instead of or in addition to giving the visible signal aforesid, put into motion
an electric bell, cause a hammer to strike a gong, or produce other effects.
The signal can be very effectually given by telephones provided with the pneu-
matic or musical signal of the description known as Gower and Roosevelt's, which
consists in general of a reed or inusical instrument fixed to the vibratory plate or
diaphragm of a telephone, so that when sounded its vibrations are communicated
directly thereto. In connection with these or similar instruments it is preferable to
regulate the length of the vibratory plate or strip of the signalling apparatus of the
present Invention, so that its vibrations shall be synchronous with those of the
reed or musical instrument.
In order that the principle of the inclined catch may be rendered more intelli-
gible 1 will now describe two of the principal modes of arranging it, reference being
had to Figures 4 and 5 of the Drawings, in which the parts necessary to explain the
action of the incline only are shewn so as to avoid complication.
The two principal modes are evidently the one in which the vibratory plate or
strip is vertical, and rests on the plane of the catch of the releasing jointed arm
which is not horizontal, the other in which the vibratory plate or strip is placed
obliquely, and rests on the plane of the catch of the releasing jointed arm which is
horizontal.
In Figure 4 the vibratory strip or plate L is vertical, and rests on the inclined
plane, terminating the releasing jointed arm T, which is caused to release by means
of the continuous action of a spring or weight P, the latter being shewn at the end
of a lever B oscillating at a, and provided with a joint or articulation at A, whilst
in Figure 5 the whole is similar, the only difference being that the vibratory strip
or plate L is oblique, and rests on the horizonal plane of the catch terminating the
releasing jointed arm T.
It will be easily understood that many variations can be made in the arrange-
ment of the inclined catch, but the examples given will be sufficient to enable
competent persons to adapt the principle to the various cases which may occur in
practice.

page_text: It is obvious that the form, dimensions, materials employed, and accessory devices
for carrying out the Invention may be varied if required.
Having now described and particularly ascertained the nature of the said Inven-
tion, 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 ine by the hereinbefore in part recited
Letters Patent is,―
First. An electric or telephone signal having a disc or other device connected with
a vibratory plate or strip, and adapted to be operated by successive vibrations of
the said plate or strip, of which vibrations no one would effect the operation, all
substantially as herein before described.
Second. The combination of a signal device, a vibratory plate or strip, a catch
connected with the aforesaid device by a pivot or hinged joint, and adapted to
engage directly with the said plate or strip, and means for moving the signal device
when the catch is disengaged by the vibrations of the strip or plate, substantially as
herein before described.
Third. The combination with a disc or other signal device of an electro magnet,
a vibratory plate or strip located in front of the poles of the said maguet, and
incans, substantially as specified, for connecting the said disc or device with the
vibratory plate or strip through the medium of an inclined plane, whereby through
successive vibrations of the said plate or strip the disc or other device is disconnected
or released to give the required signal, substantially as hereinbefore described.
Fourth. The combination with the vibratory plate or diaphragm of a telephone
of otherwise ordinary or suitable construction of a signal disc or device and a catch,
substantially as herein set forth, the said disc or device being held in position by
the arrangement of the catch with the vibratory plate or diaphragm, and released to
give the signal by the disengagement of the said catch through the vibrations of the
said plate or diaphragın, substantially as hereinbefore described.
Fifth. The combination of a sliding plate or rod, or its specified equivalent, and a
bent arm or catch pivoted thereto, and having at its end an inclined plane with a
vibratory plate or strip provided with an aperture, the said sliding piece or equi-
valent being sustained against its weight by the engagement of the said inclined
plane with an edge of the aperture, and dropping on the disengagement thereof,
substantially as hereinbefore described.
In witness whereof, I, the said John Henry Johnson, have to this my Specifi-
cation set iny hand and seal, this Nineteenth day of March, One thousand
eight hundred and eighty.
J. HENRY JOHNSON. (L..S.)