Improvements in or relating to Telephone Exchange Switch Boards.
Year: 1895

page_text: Date of Application, 8th July, 1895-Accepted, 8th July, 1896
COMPLETE SPECIFICATION.
Improvements in or relating to Telephone Exchange Switch Boards.
I, ROBERT STOCK, of Waldemarstrasse 29 Berlin, S.O. in the Empire of Germany,
Manufacturer, do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and
by the following statement :-
In the systems generally employed in large telephone central stations the switch
keys pertaining to one exchange apparatus for 200 subscribers are arranged on
vertical switch boards. Thus for every 200 subscribers as many switches are
necessary as there are conducting wires running into the central station; conse-
quently the expenses for fitting up such apparatus for large stations increase
unproportionally quickly, for instance in a station fitted for 10,000 subscribers,
they are nearly four times the amount necessary to fit up a station for 5,000
subscribers.
The present invention obviates such defects and provides means by which
considerable space may be saved as well as expense in putting up the exchange
apparatus, and at the same time a better and clearer view of the arrangement is
given to the controlling operators.
The invention, further, renders it possible to fit up a telephone central station
for twice as many subscribers as heretofore.
As is well known in the construction of the switches, it has for technical reasons
been impossible to go below a certain size, thus more than 10,000 switches cannot
be arranged on a frame within the convenient reach of one person. The present
invention offers the possibility of increasing the number of switches within the
reach of one operator up to 20,80 without increasing the space occupied.
:
The invention is illustrated in the annexed drawings ;-
Fig. 1 is a side view; Fig. 2 a plan view; Fig. 3 a section of an improved
multiple exchange apparatus ;
Figs. 4 to 8 are detail views and Fig. 9 a diagram of a telephone central station
fitted up for 20,800 subscribers.
The invention substantially consists in the particular arrangement of the switch
bands forming the switch-boards and of the hanging of the switch wires.
Each board, which is provided with a number of switches, corresponding to that
of the subscribers, is doubly used, that is, whilst hitherto only three persons could
work on one switch board and so serve only 2 to 300; in this arrangement six
persons can work on one switch-hoard and so serve 4 to 600, so only half as many
switch-boards are wanted as formerly.
To render this useful in practice, the arrangement is so made that the operators
can read the numbers equally well from both sides and the switch-board constructed
for 1,800 switches is placed horizontal and is not too wide to allow an operator
on either side to reach over to the other side. For this purpose the switch bands
(Figs. 4 and 5) are sloped towards both sides so as to be fitted to receive on
their respective sloped edges b, c, the corresponding numbers 1, 2, 3, 4 etc. and to
facilitate their being read off, from either side of the board. The bands are provided
with vertical boles to receive the spring jacks e into which are put the connecting
plugs and are fixed upon the iron supports k. The latter carry, by means of the
bolts 1, the cable supports m which are suspended pendulum like and provided with
hooks n (Figs., 7 and 8) to carry the cables i and which by their peculiar hanging
allow of a sideward movement so that the cables are always easily reached.

page_text: The whole arrangement is shown in Fig. 3. On both sides of the switch board
are placed also horizontally the plug boards which carry the plugs, and in the
two wire system also the return call switches; beneath same are arranged vertically
the annunciator frames g and horizontally the key-boards f, these latter carrying
the necessary keys and annunciators. The microphones are suspended on cords
which serve also as conductors and pass over pulleys and carry counterweights p,
allowing the microphones to be adjusted to any desired height.
As mentioned above this invention enables the number of switches reachable
from one operative centre to be increased up to 20800 or thereabouts. In the
diagrammatic plan Fig. 9 such arrangement is represented. The alternate
rows ABCD represent the exchange boards just as herein before described and
illustrated in Figs. 1 to 3 consisting of switch boards with their complete apparatus
such as annunciators battery keys plugs and the rest of the usual mechanism. The
switch boards of these rows A B C D carry the switches numbered from 1 to 10000.
The other rows E F G H and J are formed of exchange boards consisting only of
switch boards with their plugs, that is to say, having no annunciators or keys.
The spaces between the rows are for the exchange operators:
By this division of each exchange board into a principal board and an additional
board each having part of the switches the connecting devices namely the plags
and their wires must also be modified to serve on either board, and this is done
by forming each connecting device of one plug and two binding plugs, of which
latter the one is on the principal exchange board the other on the additional
board. The wire to the second plug branches off from that to the first, the con-
nection passing below the floor. These two connected plugs carry the same sign.
The apparatus is used as follows:-
The attending operators have their places before the annunciator boxes of the
rows A B C D, as soon as a latch falls and on being asked for a number between 1
and 10000 the operator connects upon the switch boards belonging to the annunciator
boxes. If a number between 10001 and 20800 is wanted the operator turns round
and makes connection upon the other switch board with the numbers 10001 to
20800 by means of the plug corresponding to that which he would have used on
the other board.
Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In a multiple exchange apparatus for telephone central stations the arrange-
ment of horizontal switch boards having bands sloped towards both sides with a
double set of numbers capable of being used on both sides.
2. In a multiple exchange apparatus as described in Claim 1 the pendulum like
suspending of the cables for the purpose of augmenting the number of the cables
corresponding to the switch bands and to render them at any time easily
reached.
3. In multiple exchange apparatus as described in Claim 1, the arrangement of
one half of the switches in rows lying behind the operator with plugs electrically
connected with the respective connecting plugs.
Dated this 8th day of July 1845
HERBERT HADDAN & Co.,
18, Buckingham Street, Strand, London, W.C.,
Agents to the Applicant.