IMPROVEMENTS IN AND RELATING TO APPARATUS FOR TELEPHONE EXCHANGE SYSTEMS
Year: 1884

page_text: I WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake & Co Patent Agents,
Southampton Buildings, London, in the County of Middlesex do hereby declare
the nature of said invention for "IMPROVEMENTS IN AND RELATING TO APPARATUS
FOR TELEPHONE EXCHANGE SYSTEMS" to be as follows :-
This invention relates to tolephone-exchange systems and to switch-boards for
the central offices of telephone systems.
That part of this invention which relates to telephone-exchangos consists in
connecting all the lines entering the exchange with each switch-board; in
separating the working attachments of the subscribers lines into groups on the
several switch-boards and in providing the lines which enter the exchange with a
relay and in so connecting the relay that any operator can connect with any line,
as hereinafter more fully set forth.
That part of this invention which relates to the switch-board consists in the
peculiar and novel construction of the board which is formed of strips differing in
color and has a series of wires which cross each other at right angles; and in the
peculiar construction of the key by means of which a metallic connection is made
and broken between any two of the wires, as hereinafter more fully set forth.
In telephone exchanges, in cities having a large number of subscribers, a great
number of switch-boards are used in order to sub-divide the labor of answering
subscribers' calls, and when a subscriber connected with one switch-board desires
to communicate with a subscriber on another board it becomes necessary to call the
attention of two operators to the call in order that the necessary connections, may
be made to place the two subscribers in communication. Such a system involves a
considerable waste of time and enhances the liability of errors, and it is the object
of this part of my invention to remedy the above defects by producing a system
which shall enable one operator to connect a subscriber on one switch-board with a
subscriber on another board, and to readily ascertain whether such line is or is not
in use. '

page_text: The object of that part of my invention which relates to the switch-board is to
increase the rapidity with which an operator may connect or disconnect two
conducting wires for the purpose of establishing or cutting off, at the central office,
communication between any two subscribers. Hence it will be seen that by the
combined use of this improved system and switch-boards, accuracy, rapidity and
reduction in the numbers of operators are secured.
According to the said invention any number of switch-boards may be used, and
all of the subscribers lines, entering the exchange, connect each with all of the
switch-boards. The whole number of these entering lines are, however, sub-divided
into groups in such manner that only a certain portion are connected with the
annunciators of each board, so that the operator of each board receives only
the calls from such subscribers as are connected with the annunciator on that
board; while any number of subscribers may be connected either on the saine or
different boards. A subscriber's line is connected with the annunciator and through
the same with a lever whereby the subscriber is connected with and disconnected
from the operator's telephone by means of a button and with the armature of the
electro-magnet by means of a post and line. A second line connects the armature
of the electro-magnet with a second button, the latter is connected with a point on
a switch-board and both lines are connected with keys by flexible wires. These
keys can be connected with any line on the switch-board, and also with any one of
the subscribers lines, since all such lines enter the switch-board. The local circuit
is from a ground or return wire through a magnet to a connecting point which
latter is connected by wires with the corresponding point on every switch-board in
the exchange, and every such switch-board is in turn connected with cach of the
other switch-boards, the magnet being connected with the switch-boards as is the
case with the line connections &. Each switch-board is provided with as many
lever switches as may be required to operate the main lines grouped in the switch-
board.
The key or plug is connected with the jack by means of a flexible wire, so that
it can be connected either with a local battery or a sounder and the ground, as may
be desired. In the normal condition, the local circuit through the megnet being
open, the armature rests against the ground connection which places a ground upon
the ingin line, the connecting line the button lever and the annunciator.
Strips of any suitable non-conducting material are provided in each of which
two rows of holes are made. Wires are inserted into these strips, crossing the
same, and passing through the centers of the holes. Other wires running
longitudinally of the strips below the first wires cross the former wires at right
angles in the centers of the holes. The whole structure, thus arranged, is secured
to a backing. Heretofore switch-boards have been made with plates perforated in
place of the first wires and such plates had to bo wider than the diameter of tho
holes and had to be placed sufficiently far apart to prevent electrical disturbance.
By using two sets of wires separated by a non-conductor, and by forming the holes
in the non-conductor, a much larger number of key-holes and a greater number of
connections can be made on a switch-board of a given size than could be made on
boards as previously constructed.
By this improved arrangement the physical labor of the operator is very
materially reduced, as a given numbor of combinations can be more conveniently
reached than heretofore. To enable the operator to follow quickly, by sight the
wire passing through any set of holes, the strips are differently colored.
To connect two wires the key is provided with a round shank divided along its
axis by a cross-cut, so as to produce four metallic points the ends of which are
rounded to facilitate the insertion of the key over the wire. The four inetallic
points are sufficiently elastic to yield slightly as they are pushed over the wire, and,
as they form two forks, they may be inserted without regard to the position of the
cross-cuts and will quickly clamp one wire by yielding in one direction and the
other wire by yielding in the opposite direction; thus making metallic connection
with both wires by four bridges. Or metallic connections, each of which, when the

page_text: key is inserted, must always be in close metallic contact with both wires making
an electric contact much superior to that produced by the bifurcated metallic plugs
heretofore used to connect a wire to the perforated plate. The improved key
cannot be inserted into the holes without making the desired connection, and no
skill or care is required in inserting the same, as the rounded points guide the key
and the spring of the legs ensures the metallic contact and electrical connection.
If for any purpose it should be desirable to cross the wires at any other than a
right angle, it is obvious that they may be so arranged in the switch-board, and
also that a key may be constructed with three legs or points and produce nearly or
quite as good results. I prefer however, the construction described, as the same is
simple and convenient in usc.
Duted this Oth day of Januaux 1001
HASELTINE, LAKE & Co.,
For the Applicant.

page_text: I WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and C° Patent
Agents Southampton Buildings, London, in the County of Middlesex do hereby
declare the nature of my invention for "IMPROVEMENTS IN AND RELATING TO
APPARATUS FOR TELEPHONE EXCHANGE SYSTEMS" and in what manner the samo
is to be performed, to be particularly described and ascertained in and by the
following statement :-
This invention relates to telephone-exchange systems, and to switch-boards and
apparatus connected therewith for the central offices of such systems.
In telephone exchanges in towns and cities having a large number of subscribers,
several switch-boards are used in order to sub-divide the labor of answering
subscribers calls, so that when a subscriber connected with one switch-board desires
to communicate with a subscriber on another board, it becomes necessary to call
the attention of two operators to the call in order that the necessary connections
may be made to place the two subscribers in communication. Such a system
involves a considerable waste of time and enhances the liability of errors; one of
the objects of this invention is to remedy the above defects by providing a system
which shall enable one operator to connect a subscriber on one switch-board with
a subscriber on another board, and to readily ascertain whether such line is or is
not in use. Another object is to increase the rapidity with which an operator may
connect or disconnect two conducting wires for the purpose of establishing or
cutting off, at the central office, communication between any two subscribers.
Hence it will be seen that by the combined use of the improved system and
apparatus accuracy, rapidity and reduction in the numbers of operators are
Eccured.
That part of the invention which relates to telephone-exchanges consists in
connecting all the lines entering the exchange with each switch-board; in separating
the working attachments of the subscribers' lines into groups on the several switch-
boards, and in providing the lines entering the exchange with relays which are so
connected that any operator can connect with any line, as hereinafter more fully
set forth.
That part of the invention which relates to the switch-board comprises a
peculiar and novel construction of the board, which is formed of strips differing
in color, and has a series of wires which cross each other at right angles; and a
peculiar construction of the key by means of which a metallic connection is made
and broken between any two of the wires, all as hereinafter more fully set forth.
In the accompanying drawing.
Figure 1 is a front elevation of the improved switch-board.
Figures 2 and 3 are similar sectional views of the same showing their operativo
connections, and the connecting wires in dotted lines.
Figure 4 is a plan view of a switch-board composed of strips, the board being
partly broken away in order to expose the oppositely crossing wires.
Figure 5 is a sectional view of the switch-board, shewing the wires embedded
in the same, and a view of the key inserted over two wires, so as to connect the
same electrically, and
Figure 6 is a similar view at right angles to Figure 5.
In Figures 1, 2 and 3, A indicates the first switch-board and B the second
switch-board. Any number of switch-boards may be used, and all of the
subscribers lines entering the exchange, connect with all of the switch-boards.
The whole number of these entering lines are, however, sub-divided into groups in
such manner that only a certain portion are connected with the annunciators of

page_text: oach board, so that the operator of each board receives only the calls from such
subscribers as are connected with the annunciator on that board; while any
number of subscribers may be connected either on the same or different boards.
a is a subscriber's line connected with the annunciator and through the same
with the jack b, whereby the subscriber is connected with, and disconnected from,
the operator's telephone by means of the button c and with the armature d of the
electro-magnet by means of the post and wire c'. The wire c² connects the
armature of the electro-magnet with the button e; the latter is connected with
the point g' on the switch-board B, and is connected with the key f by a flexible
wire. These keysff can be connected with any line on the switch-board, and also
with any one of the subscribers' lines, since all such lines enter the switch-board.
The local circuit is from a ground or return wire through the magnet / to a
connecting point i, which latter is connected by wires with the corresponding point
on every switch-board in the exchange, and every such switch-board is, in turn,
connected with each of the other switch-boards, the magnet being connected on
the board A with the point i on the switch-board B, with the point 2, on the
board C, with the point ³, and so on, as is also the case with the line connections
9, 9¹, g³, &o.
Each switch-board is provided with as many lever switches j as may be required
to operate the main lines grouped on the switch-board.
The key k is connected with the jack j by means of a flexible wire, so that it
can be connected either with the local battery l or the sounder m and the ground,
as may be desired.
In the normal condition, the local circuit through the magnet h being open, the
armature & rests against the ground connection n which places a ground upon the
main line, the connecting line c', the button c, jack b and the annunciator.
The operation of the improved apparatus is as follows that is to say-When it'
is desired to connect two inain lines, one on the board A and the other on some
other board, the calling and working connections of which are on different boards,
the operator on the board A connects the key k with the point i, which, by means
of the switch j, causes the current from the battery to close the magnet h, thereby
removing the armature & from the ground n, and affording, by incans of the key f
and point g, opportunity for making connection with the main or subscriber's line
at any switch board in the exchange. By means of the key f the subscriber's line,'
may be connected with any other main line on this switch-board.
In order to ascertain if any desired line is in use, the operator connects the
signalling arrangement m with the point of the local circuit at i, i, i³, by means of
the switch-jack j and key k; one of said points i, i, i, corresponding to the
desired main line. If this circuit is in use, a portion of the current traversing it
will pass through the sounder m and will thereby show to the operator that the-
line is in use by other parties. If no current is found passing through the
sounder m, it shows the operator that the desired line is not in use; then by
turning the jack j to connect the battery upon the local circuit, the ground will be
taken from the main line and connections can be made with it as required. The.
grounds are designated by the Figures 1, 2, 3, 4, 5 and 6, in diamonds.
l
In Figures 4, 5 and 6, of the drawings A¹, B' indicate strips of any suitable
non-conducting material in each of which two rows of holes C¹, C¹, are made.
b
The wires D¹, D' are inserted into these strips, crossing the same and passing.
over the centres of the holes C¹, C¹. The wires E¹, E', running longitudinally of
the strips A', B', below the wires D¹, D¹, cross the forner wires at right angles in
the centres of the holes C¹, C'. The whole structure, thus arranged, is secured
to the backing F'.
Heretofore switch-boards have been made with plates perforated, in place of the
wires D', D, and such plates have had to be wider than the diameter of the holes
and to be placed sufficiently far apart to prevent electrical disturbance. By using
two sets of wires. separated by a non-conductor, and by forming the holes in the
non-conductor, a much larger number of key-holes C³, C³, can be made and a

page_text: greater number of connections can be made on a switch-board of a given size than
could be made on boards as previously constructed.
By this improved arrangement the physical labor of the operator is very
materially reduced, as a given number of combinations can be more conveniently
reached than heretofore. To enable the operator to follow quickly, by sight, the
wire passing any set of holes, the strips A¹, B¹, are differently colored, as for
instance, white for A', and black for B¹.
To connect the two wires the key G is provided with a round shank divided
along its axis by the cross-cuts h, so as to produce four metallic points g³, g'-the
ends of which are rounded to facilitate the insertion of the key over the wires.
The four metallic points g, g' are sufficiently elastic to yield slightly as they are
pushed over the wires, and, as they form two forks, they may be inserted without
regard to the position of the cross-cuts and will quickly clamp the wire D' by
yielding in one direction, and the wire E¹ by yielding in the opposite direction;
thus making metallic connection with both wires by four bridges or metallic
connections, each of which, when the key is inserted, must always be in close
metallic contact with both wires, making an electric contact much superior to that
produced by the bifurcated metallic plugs heretofore used to connect a wire to the
perforated plate.
The improved key cannot be inserted into the holes without making the desired
connection and no skill or care is required in inserting the same, as the rounded
points g³, g' guide the key, and the spring of the legs ensures the metallic contact
and electrical connection.
If, for any purpose, it should be desirable to cross the wires at any other than a
right angle, it is obvious that they may be so arranged in the switch-board, and
also that a key may he constructed with three legs or points gl and produce nearly
or quite as good results. I prefer however the construction described, as the same
is simple and convenient in use.
Having now particularly described and ascertained the nature of my said
Invention, and in what mannor the same is to be performed, I declare that what
I claim is
First. The improvement in a telephone central-office system, consisting in
connecting the subscribers' wires with different switch-boards, grouping the calling
and working attachments on separate switch-boards, employing electro-magnets for
removing the ground from the line, and means for connecting the lines.
Second. In a telephone central oflice system, the combination with a group of
main lines 'connected with the annunciators of the board and the armatures of
electro magnets, of local circuits, connected with the electro-magnets, constructed to
remove the ground from the main line, by means substantially as described.
Third. In a telephone central-office system, the combination with a group of
main lines connected with the annunciators and the armatures of electro-imagnets,
of local circuits connected with the electro-magnets, line-wires connecting
subscribers wires of other boards, and means substantially as described, by which
any line can be connected with any other line, as described.
Fourth. The combination with the line wires connected with the switch-board
through the annunciators and to the armatures of the electro-magnets, as described,
and the terminals of other subscribers' lines not so connected, of the jack j,
sounder m and battery 1, constructed to connect the calling-subscriber's line with
the called line and ascertain whether the same is or is not in use as described.
Fifth. The improved method of breaking the ground connection of any main
line substantially as herein before described.
Sixth. The combination with the subscribers' lines connected with the
annunciators of a switch-board, and other subscribers' lines connected with the
switch-hoard, of the electro-magnets h h, armatures d d, connecting points 9 g¹g²,
and, and the switches j and sounders m, all constructed and arranged to
operate substantially as described.

page_text: Seventh. In a telephone-oflice switch-board, the combination with the wires
D' E embedded in a non-conducting material provided with the holes C¹, C₁, of a
key constructed to inake a metallic connection with two wires when inserted in one
of the said holes as described.
Eighth. A telephone office switch-board consisting of strips differing in color
and having wires embedded at right angles to each other and crossing the centres
of holes in which bifurcated keys when inserted connect two wires, as, and for the
purpose, described.
Ninth. The combination with the wires D¹ and E' and the strips A', B', provided
with the holes C¹³, of the key G¹ provided with four points g¹¹ constructed to
pass over the wires and connect the same clectrically, as described.
Tenth. A key constructed to connect electrically two sets of wires crossing each
other at right angles, or at nearly right angles, provided with legs or points
constructed to spring both wires, tho ends of said points being formed so as to
guide the key over the wires, as described.
1
1001
HASELTINE, LAKE & Co.,
For the Applicant.