Improvements in Automatic Telephone Exchanges.
Year: 1891

page_text: Date of Application, 6th May, 1891
Complete Specification Left, 8th Feb., 1892-Accented, 12th Mar., 1892
PROVISIONAL SPECIFICATION.
Improvements in Automatic Telephone Exchanges.
I WILLIAM WILSON HORN of the firm of Horn and Son 151 Strand in the
County of Middlesex Patent Agent do hereby declare the nature of this invention
(a communication to me from Almon B. Strowger of Kansas City State of
Missouri United States of America Inventor) to be as follows:-
My invention relates to an improvement in automatic, telephonic, telegraphic
and other electrical exchanges.
The object is to provide means whereby a person at one station may make
connection with any other station in the system by means of electrical appliances
without the aid of an operator at the central station.
A further object is to provide means of the above character which shall be
reliable and adapted to general use.
With these ends in view my invention consists in certain features of construction
and combination of parts as will be hereinafter described.
The same general plan is adopted as in the systems now in use in that of having
a principal or central station (central office) and a number of sub-stations, the said
sub-stations being placed in electrical connection with each other at the central office
by and thro' line-wires, which line-wires, for the sake of brevity will be designated
phonic wires" (introducing the ancient obsolete form) but differ in that of having,
in addition to the said phonic wires, a series of wires (one or more) to operate the
hereinafter described mechanisms located at the central office.
65
At the sub-stations are the appliances which are used to transmit and receive
communications, as telephones and keys. At the central office are arranged in
methodical order as many switch-cylinders, with their attendant mechanisms, as
there are sub-stations. The above mentioned phonic wires trend within the central
office in close proximity to each cylinder.
From each phonic wire and attached thereto, wire terminals connectives, or
"legs" extend to the inside of each cylinder there being as many connectives
attached to each phonic wire as there are sub-stations.
With this brief outline I will proceed to more fully describe my invention and its
workings.
A hollow cylinder constructed of glass wood or other suitable substance which is
a non-conductor of electricity is supported in any well known or approved manner,
such cylinder being provided with perforations arranged in transverse and vertical
rows.
The wire connections extend from the inside of the cylinder through the
perforations to the main line wires attached thereto.
Their use is to conduct the electricity when in contact with the circuit-closing
needle to and via the line wires to the desired sub-station. A circuit-closing sleeve
is firmly attached to the lower end of the sleeve rod. Within this circuit-closing
sleeve is closely fitted a circuit-closing needle held in such a manner as to be in
perfect electrical contact with the wire terminal by a spring. The rod is located
along the axle line of the cylinder and is free to rotate and move longitudinally.
The lower end of the rod is sleeved, into which is inserted the upper portion of a
ratchet-rod. This sleeve construction between the rods allows the ratchet-rod to
have a longitudinal motion only thereby keeping the ratchet-teeth continuously
towards its attendant pawl.
The said ratchet-rod is provided outside of the cylinder and conveniently below
it with a series of ratchet-teeth by means of which the rods may be moved
longitudinally

page_text: The wheels thro' the hub of which the rod extends so as to cause the rotation of
the rod and at the same time admit of its longitudinal sliding movement therein are
provided on their peripheries with a series of ratchet-teeth by which the rod is
rotated and with it the circuit-closer.
Suitable levers are provided having pawls pivoted in their ends in position to
engage the ratchet-teeth with which they are respectively in contact.
Each lever has a vibratory movement and is oscillated by the alternate energizing
and de-energizing of their respective magnets thereby imparting motion to its
adjacent ratchet-teeth and consequently the circuit-closing needle.
At each pulsation of the push button at the sub-station made at the will of the
operator causes through the channels thus described the circuit-closing needle to
move from row to row and from wire to wire in the row.
Magnets are located in suitable positions that when energized by the manipulation
of certain keys at the sub-stations, operate their respective levers. A set of
magnets are also located in suitable positions that when energized their respective
levers serve to release the pawls from their engagement with the ratchet-teeth and
allow the circuit-closing needle to assume the initial position by the aid of gravity
and a spring.
At each sub-station there is a set of keys, each key is connected by wire with its
respective lettered magnet at the central office and when pressed an electrical
circuit is established it being understood that both ends of the wire are grounded
or connected with a return tap, it also being understood that a battery is used to
generate the electricity and may be located at the sub-station between the keys and
the ground.
The line-wire extends from the telephone to and within the central office, there
connected by the circuit-closing connective wire to the circuit-closing needle and
also by a connective to the inside of each cylinder.
Each perforation of the cylinder is numbered with respect to an initial or starting
point on the cylinder-for example, in rows numbered 1, 2, 3, 4 &c. from the lower
end of the cylinders upwardly, and by places in each row-as for example 1, 2,
3, 4 &c. to the right or left of a given vertical row, so that, supposing there were
one hundred perforations in each of the rows No. 310 would be in the third_row
from the bottom ten spaces to the right or left of the vertical initial line. Each
connective wire and phonic line-wire with which the connections are attached, is
also numbered to correspond with the number of the perforations through which
the terminals extend.
The person wishing to place his transmitter and earphone in connection with
those of another he will do so by successively pressing or depressing the keys which
cause the circuit-closer to move.
The person at the second telephone will take down his earphone. The two are
then able to converse with each other. When conversation is ended the person
calling up hangs up his earphone depresses a key, which causes the magnets to be
energized attracting the armatures, thereby withdrawing the several pawls from
their engagement with the ratchet-teeth and allow the circuit-closer to fall and
return to its initial point.
If a person has called up the wrong number he will push the key and start over
again.
The size of the cylinder will depend solely upon the number of wires required in
the system and the distance apart which it may be found most expedient to place
them and it is also evident that various slight changes might be resorted to in the
mechanical construction of the several parts which I have described without
materially departing from the spirit and scope of my invention and hence I do not
wish to be limited strictly thereto.
Dated this 6th day of Mar 1901
HORN & SON,
Applicant's Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in Automatic Telephone Exchanges.
I WILLIAM WILSON HORN of the firm of Horn and Son of 151 Strand in the
County of Middlesex Patent Agent do hereby declare the nature of this invention
(a communication to me from Almon B. Strowger of Kansas City, State of
Missouri United States of America Inventor) and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
This my invention relates to an improvement in automatic, telephonic, telegraphic
and other electrical exchanges.
The object is to provide means whereby a person at one station may make
connection with any other station in the system, by the aid of electrical appliances,
without the assistance of an operator at the central station.
A further object is to provide means of the above character which shall be
reliable and adapted to general use.
With these ends in view my invention consists in certain features of construction
and combination of parts, as will be hereinafter described and pointed out in the
claims.
The same general plan is adopted as in the systems now in use in that of having
a principal or central station, (central office) and a number of sub-stations, the said
sub-stations being placed in electrical connection with each other at the central
office by and through line-wires, which line-wires for the sake of brevity, will be
designated "phonic" wires (introducing the ancient obsolete form) but differ in
that of having in addition to the said phonic wires a series of wires (one or more)
to operate the hereinafter-described mechanisms located at the central office. At
the sub-stations are the appliances which are used to transmit and receive com-
munication as telephones and keys.
At the central office are arranged in
methodical order as many switch-cylinders, with their attendant mechanisms as
there are sub-stations. The above mentioned phonic wires trend within the central
office in close proximity to each cylinder.
From each phonic wire and attached thereto, wire terminals, connectives or
"legs" extend to the inside of each cylinder there being as many connectives
attached to each phonic wire as there are sub-stations.
With this brief outline I will proceed to more fully describe my invention and
elucidate its workings by the aid of the accompanying drawings.
Figure I represents in a perspective view my invention showing at a distant
sub-station one telephone, and its exchange device at the central office, also the
main line-wires connecting the central office with the sub-station.
Fig. II represents four of such devices as is represented by Fig. I showing the
manner in which the cylinders are connected, also the trend of the electrical current
from one sub-station to another through the central office.
Fig. III is a plan view of a series of cylinders line-wires and connectives showing
the normal position of the circuit-closers.
Fig. IV is a sectional view showing the magnets levers and pawls by which the
device is operated.
Fig. V is a detail view of the ratchet wheels and pawls for operating the same.
Fig. VI is a sectional view of the cylinders, showing more clearly the construction
of the circuit-closer and feather and groove attachment.
Referring to the drawings by letter A represents a hollow cylinder constructed
of glass wood or any other suitable substance which is a non-conductor cf electricity
supported in any well known or approved manner. The cylinders are provided
with perforations a arranged in transverse and vertical rows.
B represents the wire connections extending from the inside of the cylinder
through the perforations a to the main line-wires N and is attached thereto

page_text: Their use is to conduct the electricity when in contact with the circuit-closing
needle C C' to and via the line-wires N to the desired sub-station. The terminals of
said connectives within the cylinder are shown at 6 Fig. VI. In this last named figure
the circuit-closing arm is represented in parts in which C is the circuit-closing
sleeve and is firmly attached to the lower end of the sleeve rod D. Within this
circuit-closing sleeve is closely fitted a circuit-closing needle C¹ held in such a
manner as to be in perfect electrical contact with the wire terminal by the
spring c. The rod D (see Fig. VI) is located along the axle-line of the cylinder
and is free to rotate and move longitudinally. The lower end of the rod D is
sleeved, into which is inserted the upper portion of the ratchet-rod D'.
This sleeve construction between the rods D and D¹ allows the ratchet-rod D' to
have a longitudinal motion only, thereby keeping the ratchet-teeth d continuously
towards its attendant pawl.
The ratchet-rod D' is provided outside of the cylinder A and conveniently below
it with a series of ratchet-teeth d by means of which the rods D and D₁ are moved
longitudinally. The wheels E and E' through the hub of which the rod D extends
with a feather and groove connection R (see Fig. VI) so as to cause the rotation
of the rod D and at the same time admit of its longitudinal sliding movement
therein are provided on their peripheries with a series of ratchet-teeth e and e¹ by
which the rod D is rotated, and with it the circuit-closer C and C'.
G H I represent levers having pawls g, h, i, pivoted in their ends in position to
engage. the ratchet-teeth with which they are respectively in contact. Each lever
has a vibratory movement, and is oscillated by the alternate energizing and
de-energizing of their respective magnets, thereby imparting motion to its adjacent
ratchet-teeth and consequently the circuit-closing needle C. At each pulsation of
the push button at the sub-station made at the will of the operator causes through
the channels thus described, the circuit-closing needle C¹ to move from row to row
and from wire to wire in the row. When only three levers are used the dog T (see
Figs. I and II) would be necessary. Its use is obvious.
The magnets K K K are located in suitable positions that when energized by
the manipulation of certain keys at the sub-station, operate their respective levers.
A set of magnets K K K K are also located in suitable positions that when
energized their respective levers P serve to release the pawls from their engage-
ment with the ratchet-teeth and allow the circuit-closing needle C C¹ to assume
the initial position by the aid of gravity and the spring S. At each sub-station
there is a set of keys marked respectively G' H' l'and P. Each key is connected
by wire with its respective lettered magnet at the central office, and when pressed
an electrical circuit is established, it being understood that both ends of the wire
are grounded or connected with a return trap, it also being understood that a
battery is used to generate the electricity and may be located at the sub-station
between the keys and the ground. The line-wire N extends from the telephone to
and within the central office, there connected by the circuit-closing connective
wire W to the circuit-closing needle C and also by connective B to the inside of
each cylinder.
Each perforation a of the cylinder A is numbered with respect to an initial or
starting point on the cylinder-for example, in rows numbered 1, 2, 3, 4, &c. from
the lower end of the cylinders upwardly, and by places in each row, as for
example, 1, 2, 3, 4, &c.—to the right or left of a given vertical row, so that,
supposing there were 100 perforations in each of the rows, No. 310 would be in
the third row from the bottom, ten spaces to the right or left of the vertical
initial line.
Each connective wire B and phonic line-wire N, Figs. II and III with which
the connections are attached, is also numbered to correspond with the number of
the perforations, a, through which the terminals extend.
The person wishing to place his transmitter and earphone in connection with
those of another, he will do so by successively pressing or depressing the keys,
which cause the circuit-closer C C₁to move. For example, if telephone 288 wishes

page_text: to place himself in connection with telephone 315, he will do so by pressing the
key marked G¹ three times, then the key marked H¹ once, and then the key
marked I five times.
His circuit-closer C C' is then in contact with wire terminal No. 315. In
Fig. II sub-station No. 288 is represented as being in connection with sub-station
No. 315. This is known by the position of the circuit-closer C of cylinder No. 288,
the course of the electrical current being indicated by arrows.
Had its circuit-closer C been turned to the next wire indicated in the drawings,
288 would be in connection with 11. The person at the second telephone 315 will
take down his earphone. The two are then able to converse with each other.
When conversation is ended, the person calling up hangs up his earphone, depresses
key marked P¹ which causes the magnets K¹ to be energized, attracting the
armatures, thereby withdrawing the several pawls from their engagement with the
ratchet-teeth and allow the circuit-closer C C¹ to fall and return to its initial
point.
If a person has called up the wrong number, he will push the key marked P¹ and
start over again.
The size of the cylinder A will depend solely upon the number of wires required
in the system, and the distance apart which it may be found most expedient to place
them, and it is also evident that various slight changes might be resorted to in the
mechanical construction of the several parts which I have described without
materially departing from the spirit and scope of my invention, and hence I do not
wish to be limited strictly thereto.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. In a system of telephone telegraph or other electrical exchange, the com-
bination with a series of wires leading to different stations in the system and having
their ends insulated and held in curved rows, of a contact needle supported at the
axis of the rows, mechanism for moving the needle from row to row, mechanism
for moving the needle along the row, magnets for actuating said mechanisms, and
wires leading from a sub-station for conducting electricity to energize the said
magnets, substantially as set forth.
2. In a system of electrical exchange the combination, with an insulating
cylinder, a system of wires having their ends extending to the inside of the
cylinder, and a rotary and longitudinally movable rod located at the axis of
the cylinder, of a contact needle attached to the rod, levers for moving the rod
longitudinally, levers for rotating the rod, magnets for actuating the levers and
means for energizing the maguets at pleasure, substantially as set forth.
3. In a system of electrical exchange, the combination, with an insulating curved
surface, a system of wires having their ends extending to and through said surface
to the concave surface thereof and a rotary and longitudinally movable rod located
at the axis of curvature, of a contact needle fastened to the rod levers for moving
the rod longitudinally-levers for rotating the rod, magnets for vibrating the
lever, and means for energizing the magnets at pleasure, substantially as set
forth.
4. In a system of electrical exchange the combination, with an insulating
cylinder, a system of wires having their ends extending to the inside of the cylinder
and a rotary and longitudinally-movable rod located at the axis of the cylinder of a
sleeved arm fastened to the rod, a contact needle, levers for moving the rod longi-
tudinally, levers for rotating the rod, magnets for actuating the levers, means for
pressing the needle outwardly, and means for energizing the magnet at pleasure,
substantially as set forth.
5. In combination, the set of wires having their ends secured in a cylinder the
cylinder, the rod at the axis of the cylinder the pieces fastened to the rod, the
levers provided with pawls pivoted thereto for actuating the rod the magnets for

page_text: actuating the levers, the magnets for actuating the pawls, the keys at the sub-
station, and the wires connecting the keys with the actuating magnets substantially
as set forth.
Dated thi th
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1000
HORN & SON,
Applicant's Agents.