IMPROVEMENTS IN ELECTRICAL SIGNALING APPARATUS, AND IN CIRCUIT CONNECTIONS ADAPTED TO FIRE ALARMS, MESSENGER CALLS, AND TELEPHONES."
Year: 1881

page_text: LETTERS PATENT to James Urquhart Mackenzie, of the City and State of
New York, United States of America, for an Invention of "IMPROVEMENTS
IN ELECTRICAL SIGNALING APPARATUS, AND IN CIRCUIT CONNECTIONS
ADAPTED TO FIRE ALARMS, MESSENGER CALLS, AND TELEPHONES."
PROVISIONAL SPECIFICATION left by the said James Urquhart Mackenzie
at the Office of the Commissioners of Patents on the 2nd August 1881.
JAMES URQUHART MACKENZIE, of the City and State of New York, United
States of America. "IMPROVEMENTS IN ELECTRICAL SIGNALING APPARATUS, AND
IN CIRCUIT CONNECTIONS ADAPTED TO FIRE-ALARMS, MESSENGER CALLS, AND
TELEPHONES."
In connection with messenger calls and fire-alarms, call boxes have been placed at
different stations and connected by wires to a central office, and on moving a
handle a call or alarm is given at the central station corresponding in its number
to the instrument whose handle was moved. This system renders it necessary
that each call box be adapted to send its own designated number, and hence the
wheel or other device that makes and breaks the circuit is different in one box
from those in all the others. If any one call box gets out of order another cannot
be substituted unless especially prepared to transmit the certain number allowed
to that station.
The object of this improvement is to construct all the call boxes alike, and to
allow each call box to be set to the desired number; hence such call box can be
used at any station to indicate the station number, or it can be used in connection
with telephone lines to denote the number of the station or subscriber with which
the caller desires to be connected at the central office or exchange; or the instru-
ment can be used to denote what is desired in the messenger service by indicating
one number after another according to a pre-arranged code, or by giving a certain
set of electric pulsations upon the line for certain signal.
My improved instrument that is adapted to these objects is provided with two
or more movable number carriers that are adapted to give pulsations in the line

page_text: current corresponding to the character or number exposed to view. Each number
carrier has upon it the numerals 0, 1, 2, and so on to 9, and also contact blocks
adapted to make as many pulsations on the line or breaks and closures of the circuit
as the number that is exposed to view.
The number carriers are either straight or circular. In some instances these
number carriers are plates set to slide endwise behind a face plate in which are
openings; on one side of the number carrier there is a row of figures, one of which
can be seen through the opening in the face plate, and on the other side are the
contact blocks corresponding to the numbers. The number carriers are held in
place by ratchets or clamp screws.
In other instances the number carriers are short cylinders placed upon a shaft,
the numbers being at the ends of arms extending out radially from the cylinders,
and the contact blocks being on the surfaces of the cylinder adjacent to each arm.
There is a spring circuit closing device that is moved across the contact blocks
to open and close the electric circuit. This circuit closing device will be moved in
a line parallel to the axis, when the contact blocks are upon cylindrical number
carriers, or said circuit closer may move in a straight line or swing on an arın
when the number carriers are plates, so that in crossing the contact blocks the
number carriers will cause the circuit closer to open and close the circuit, and also
give the required pause between the pulsations for one number and those for the
next number. By this construction one signal box can be set to give any desired
signal within its capacity, or moved to give one sigual after another.
The circuit connections are arranged with reference to the instruments with
which the signal box is to be used. An automatic switch is applied in the signal
box to change the circuit connections, so that when the circuit closer is moving in
one direction the signals will be given, but when returning or moving in the other
direction signals will not be given.
When this signaling apparatus is used with telephones the circuit connections
are provided with switches and an inductorium, so that after the person to be
spoken with has been called, the transmitting instrument battery and primary of
the inductorium are in circuit, and the secondary and receiver are in the line
circuits.
In some instances the switches are made with springs to close contact, and in
other instances they are made by an arm bearing upon a plate and moved by the
same devices as the circuit closer.
It is preferable to move the circuit closer in one direction by hand and in the
other direction by a spring, a train of gearing and an escapement or vibrator being
provided-to-prevent-too-rapid movement.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Urqubart Mackenzie in the Great Seal Patent Office on the
2nd February 1882.
JAMES URQUHART MACKENZIE, of the City and State of New York, United
States of America. "IMPROVEMENTS IN ELECTRICAL SIGNALLING APPARATUS, AND
IN CIRCUIT CONNECTIONS ADAPTED TO FIRE-ALARMS, MESSENGER CALLS, AND
TELEPHONES."
In connection with messenger calls and fire alarms, call boxes have been placed
at different stations and connected by wires to a central office, and on moving a
handle a call or alarm is given at the central station corresponding in its number
to the instrument whose handle was moved. This system renders it necessary that
each call box be adapted to send its own designated number, and hence the wheel
or other device that makes and breaks the circuit is different in one box from those
in all the others. If any one call box gets out of order, another cannot be
substituted unless especially prepared to transmit the certain number allotted to
that station.
The object of this improvement is to construct all the call boxes alike, and to
allow each call box to be set to the desired number, hence such call boxes can be
used at any station to indicate the station number; or it can be used in connection
with telephone lines to denote the number of the station or subscriber with which
the caller desires to be connected at the central office or exchange; or the instru-
ment can be used to denote what is desired in the messenger service by indicating
one number after another, according to a prearranged code, or by giving a certain
set of electric pulsations upon the line for certain signal.
My improved instrument that is adapted to these objects is provided with two
or more movable number carriers that are adapted to give pulsations in the line
current corresponding to the character or number exposed to view. Each number
carrier has upon it the numerals 0, 1, 2, &c., to 9, and also contact blocks adapted
to make as many pulsations on the line or breaks and closures of the circuit as the
number that is exposed to view.
The number carriers are either straight or circular. In some instances these
number carriers are plates set to slide end wise behind a face plate in which are.
openings on one side of the number carrier there is a row of figures, one of which
can be seen through the opening in the face plate, and on the other side are the
contact blocks corresponding to the numbers. The number carriers are held in
place by ratchets or clamp screws.
In other instances the number carriers are short cylinders placed upon a shaft,
the numbers being at the ends of arms extending out radially from the cylinders,
and the contact blocks being on the surfaces of the cylinder adjacent to each arm.
There is a spring circuit closing device that is moved across the contact blocks
to open and close the electric circuit; this circuit closing device will be moved in a
line parallel to the axis when the contact blocks are upon cylindrical number
carriers, or said circuit closer may move in a straight line or swing on an arm when
the number carriers are plates, so that in crossing the contact blocks the number
carriers will cause the circuit closer to open and close the circuit, and also give the
required pause between the pulsations for one number and those for the next
number. By this construction one signal box can be set to give any desired
signal within its capacity, or moved to give one signal after another.
The circuit connections are arranged with reference to the instruments with
which the signal box is to be used. An automatic switch is applied in the signal
box to change the circuit connections, so that when the circuit closer is moving in

page_text: one direction the signals will be given, but when returning or moving in the other
direction signals will not be given.
When this signaling apparatus is used with telephones the circuit connections
are provided with switches and an inductorium, so that after the person to be
spoken with has been called, the transmitting instrument battery and primary of
the inductorium are in circuit, and the secondary and receiver are in the line
circuits.
In some instances the switches are made with springs to close contact, and in
other instances they are made by an arm bearing upon a plate, and moved by the
same devices as the circuit closer.
It is preferable to move the circuit closer in one direction by hand, and in the
other direction by a spring, a train of gearing and an escapement or vibrator being
provided to prevent too rapid movement.
In the Drawings Figure 1 is an elevation from the back of the indicator in a flat
form, a portion of the parts being removed; Figure 2 is a plan, the number carriers
and front plate being in section; Figure 3 is an elevation of the instrument with
the number carriers in a circular form, the front plate being removed; Figure 4
shows part of the front plate; Figure 5 represents a cross section of the instru-
ment; Figure 6 is a diagram representing the circuits in a telephone system
including this signal instrument; Figure 7 is a section vertically of one of the
slides and the front plate; and Figure 8 is a plan view of the traveller, switch,
spring, and plate.
The number carriers a arc either in the form of flat plates, as shown in Figures 1
and 2, or in the form of round wheels, as seen in Figures 3 and 5. In either instance
cach one is divided into ten parts, with numerals 1 to 0 on the respective sections,
as represented. There is also upon each number carrier ranges of contact blocks b
corresponding to the number with which it is associated.
There is a contact lever c on a fulcrum d that is adapted to be moved across the
blocks and by them vibrated, so as to open and close an electric circuit between
the points 3 and 4, or to operate a reversing key to throw into the circuit positive
and negative currents alternately.
The traveller is adapted to be moved endwise upon the supporting rod or
slide, and this traveller carries the contact lever c and its tooth c¹ across the
contact blocks b.
The number carriers a, in Figures 3 and 5, are upon a central shaft & supported
on brackets within the case m, and the numbers are at the ends of arins that
project through slots in the front plate u, and the number carriers can be turned
-around-to-bring any desired numbers into line with the arrow mark on the front
plate, see Figure 4, or to any other designated point, which will bring into the
path of the travelling contact lever a range of blocks b corresponding to the
numbers indicated.
In Figures 1 and 2 the number carriers a, a, are in the form of flat plates
supported in slides formed between the back of the front plate u and the back
plate u, there being a slot in the front plate in line with the travelling circuit
closer, that is, moved across the back of the number carriers and in contact with
the range of circuit closing blocks, it being understood that the numbers are upon
the faces of these slides, and the same are visible through the transverse slot in the
plate us.
In the front plate u there is a vertical slot 20 in front of each number plate a
for a stud 21 upon such number plate, by means of which the plate may be moved
up or down to bring the desired numbers into the position for action in transmitting.
These parts are shown in the detached view, Figure 7. There is also a stationary
spring detent 22 with double inclined ends passing in between the number blocks
to hold each plate in position.
The traveller inay be drawn in one direction by the cord or wire cord 9 with a
button end, and a contractile spring is preferably employed to move the traveller
in the other direction. I have shown the same cord gas passing beyond the

page_text: traveller and around the spring barrel r, to which is connected a gear wheel 71
acting upon a pinion and an escapement with a small pendulum or vibrator s that
serves to prevent the movements being too rapid.
It will now be understood that if this instrument is connected so as to make and
break the circuit between 3 and 4, that one signal may be given by the closing of
the circuit and the next by the opening of it, hence the numeral 1 will be indicated
by a long block, as denoted in Figure 1 by the dotted numbers, the numeral 2 by
a short block that will close and then open the circuit as the tooth c is drawn over
the block b, the numeral 3 will be indicated by a short and then a long block, and
so on, the long block producing a pause in the pulsation with a closed circuit, and
the long blank producing a pause in the pulsation with an open circuit.
At the receiving station the signal may be received by one magnet with an
armature lever and hammer between two bells, or with two hammers on one lever
so as to strike on opposite sides of the bell near one edge, and thereby give a stroke
on the opening as well as the closing of the circuit, the number of strokes between
each pause denoting the numbers successively.
I prefer to use a switch spring t upon the traveller h; the bent end of the spring
will pass beneath the plate when the traveller is moving in one direction, and it
will yield when it reaches the inclined end of the plate v, and pass above said
plate vso as to remain in contact when moving back in the other direction
to place the traveller in the electric circuit, and cause the pulsations in that
circuit to be made by the contact of the circuit closer with the number blocks.
At the end of the case is a key w, w¹, made of two springs with contact points to
maintain a closed circuit when the instrument is at rest.
Referring to Figure 6 it will be understood that A represents a receiving
telephone instrument; B, a battery; 6, an induction coil; D; a transmitting
telephone instrument; E, the switch lovers operated as now usual by the telephone
receiving instrument A when it is hung on or taken off the hooked end of the
switch lever; F is the lightening protector plates; G, the ground, and H the electro
magnet of the call; and L, the line.
In the normal condition the circuit is closed at the key w, w¹, so that the
telephones can be used in transmitting or receiving as usual, but when this signal
or call is operated the main line circuit is broken automatically at w, w¹, and the
current from the battery passes in the direction of the arrow to ground, back by
line to the plate v, insulating spring t, and insulated contact screw and point 3 to
the point 4, and lever c, and bar k, and return wires 15 to battery. At the distant
station the pulsations of the current act in the electro magnet H to give the signal,
the circuit thereof being closed between line L through w, w, switch 18, wire 19,
through electro magnet and wire 20 to ground.
In all instances when the signalling instrument is in the normal position, the
switch w, w is closed automatically by the spring acting upon the traveller, and
therefore the circuit is adapted for use with a telephone or other instrument.
In order to send reverse currents upon the line by the action of the traveller and
circuit breaker, it will be necessary to use a circuit reversing key upon the traveller.
instead of the plain circuit closing lever, and to connect both ends of the battery
to the instrument as well as the line and ground; these connections however are
of well known character.
It will be evident that this instrument is adapted to transmit the selected signals
into as many circuits as may be connected with the instrument, or the signals may
be repeated into numerous circuits by means of relay magnets, or mechanism
performing the same duties.
In some instances the contact lever c will be upon a swinging arm and move
in the arc of a circle, and the number carriers a will be in the form of plates that
can be moved endwise as aforesaid, but the number blocks will be made as arcs
of circles, so that the contact lever may move across them properly.
In Figure 9 an instrument of this character is shown with the face plate
removed; Figure 10 is an elevation of the face plate; Figure 11 is a rear view of

page_text: the same, and Figure 12 is an inverted sectional plan of the contact lever and
number carriers.
i
The letters of reference corresponding to those in the foregoing description are
applied to the parts in these Figures, and the operations are identical, the only
differences being that the contact lever c is carried upon an arm h that swings in
the are of a circle upon the shaft h, to which a volute spring 30 is applied to turn
it back to its normal position.
There is an escapement and vibrator 2 that prevents too rapid a movement
while the circuit is being manipulated, and in place of the contact plate v and
spring I employ an insulated swinging circuit changer or switch v² and contact
plates and v
When the parts are at rest, the, spring having moved the arm h to the left,
Figure 9, has by a pin 31 swung the switch 2 into contact with the plate v³,
and thereby closed a circuit from the line L through the binding post 32, and
insulated switch to the insulated plate v³, and to post 33 earth. This circuit
remains closed while the instrument is at rest, but when the handle 3 outside the
instrument is moved and the arm / carried to the right the contact lever c runs
across the blocks b, but gives no signal, because the battery B is not in circuit; but
when the arm h is nearing the end of its movement it comes into contact with the
pin 35 and moves the switch 2 out of contact with v³, and into contact with v
which is not insulated, and the parts assume the position shown in the diagram,
Figure 13, hence the circuit of the battery B is completed, and the current passes
from ground through battery B to the binding post 34, and by the insulated con-
nection to the insulated spring 3 on the arm h, and by the pin 4 and contact
lever c when in contact with 3, and through the arm h and by the frame of the
machine or by a wire to the contact plate v1; thence by the insulated switch vi and
';
post 32 to the line L.
The switch 2 remains in contact with while the arm and circuit lever c
travel across the number blocks and make and break the circuit between 3 and c,
and give the electric pulsations and signals to the distant station, as before
described, or in connection with telephones, as shown in the diagram, Figure 6;
but as soon as the signals have been given, but before the arm h finishes its move-
ment, the said arm comes in contact with the pin 31 and moves the switch v²,
breaking contact between the same and 4, and restoring the earth connection for
the line L through 32, v2, v3, and 33, to ground.
It will be evident that the shapes and arrangements of the parts may be varied
to suit particular uses to which this Invention is to be applied, or the telegraphic
-or-telephonic instruments employed.
I claim as my Invention,-
more
First. In an electric signalling apparatus the combination of two or
movable number carries, each provided with contact blocks corresponding to a
series of numerals or characters, and a travelling circuit closer operating to make
and break the electric circuit, so that the signals of transmission may be varied,
substantially as set forth.
Second. In an electric signalling apparatus the combination of two or more
movable number carriers and contact blocks corresponding to a series of numerals
or characters, means for visually indicating when the carriers are placed for the
desired signal, and a travelling circuit closer operating to make and break the
electric circuit, so that the signals for transmission may be varied, substantially as
set forth.
Third. In an electric signalling instrument the combination with two or more
movable number carriers and a travelling circuit closer of an automatic key or
switch in the line circuit closed by the action of the traveller when at rest, and
opened when the traveller is moved, substantially as set forth.
Fourth. The combination with two or more number carriers of a circuit closing
lever adapted to be moved across the number carriers and contact blocks upon the
number carriers, and alternate long blocks and long recesses to produce a pause

page_text: with an open circuit after one number has been indicated, or a pause with a
closed circuit when the next number is indicated, whereby the numbers can be
indicated and pauses obtained between one number and the next upon either an
open or closed circuit, substantially as set forth.
Fifth. In an instrument for transmitting signals telegraphically the combination
with the movable number plates of a travelling circuit closer, a switch and contact
plate constructed so that the signal is given when the traveller is moving in one
direction, and the circuit is automatically broken when the traveller is moving in
the other direction, substantially as set forth.
In witness whereof, I, the said James Urquhart Mackenzie, have hereunto
set my hand and seal, this Thirteenth day of January, A.D. One thousand
eight hundred and eighty two.
Witnesses,
CHAS. H. SMITH, 140, Nassau St., New York.
J. HAILE,
"
"
J. U. MACKENZIE. (L.S.)