Improvements in Electric Switches and Safety Fuses for Supply Station Distributing Boards.
Year: 1889

page_text: Date of Application, 24th Sept. 1889-Accepted, 9th Nov., 1889
COMPLETE SPECIFICATION.
Improvements in Electric Switches and Safety Fuses for Supply
Station Distributing Boards.
We CHARLES MARK DORMAN of 24 Brazennose Street Manchester in the County
of Lancaster Electrical Engineer and REGINALD ARTHUR SMITH of 24 Brazennose
Street Manchester in the County of Lancaster Electrical Engineer 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 :-
The object of this Invention is to simplify the operation of coupling the various
circuits for conveying electric currents with or uncoupling them from the dynamos
accumulators or other sources of current in a central or distributing electric supply
station, also to shorten the time necessary for the insertion of a new safety fuse in any
of the circuits, and in the case of high tension currents to render all the above
mentioned processes safe and free from danger to the operator.
To carry out our invention we arrange all the contact pieces which are connected
with the various sources of supply or distributing circuits or generally any part of the
distributing switch fuse or coupling apparatus which when the switch is
has a
open
high electric potential in such a position that they cannot easily be accidentally
touched by the hand or other part of the person of the operator-This position is
generally on the back of the slab or board to which the apparatus is fixed and not in
front where the operator generally stands.
Referring to the drawings accompanying this specification
=
Fig. 1 is an elevation and fig. 2. a section of a board on which are mounted six
of our improved switches arranged for coupling three Dynamos or other sources of
supply and three circuits in parallel.
Fig. 3 is an enlarged section showing one pair of contacts.
Fig. 4. is an end view and Fig. 5 an elevation of an easily replaceable fuse.
Fig. 6 is an end view and Fig. 7 an elevation of one of the coupling bars.
:-
At the other side of the Board to that on which the operator generally stands
are, in the case of each switch, fixed six contacts a, b, c, d, e and f. These contacts
are generally arranged in a straight line and are permanently connected as follows:-
a and respectively with the positive and negative lead of the outside circuit,
c and d respectively with the positive and negative source of supply, is arranged in a
straight line between a and c, and e in a straight line between d and f.
The object of the contact pieces band e is to enable the operator to cross-couple the
sources of supply and distributing circuits as hereafter described.
In a convenient position generally in a line parallel with the above-mentioned
contact pieces we arrange a lay shaft p on which are mounted six arms or lovers n
made of an insulating material and bearing at their extremities six metallic
pieces a 1, 61, c1, d 1, e1, & f1-When the lay shaft is moved by means of the bandle
into the "
on" position these contact pieces a 1, 61, c1, d 1, e1 and f1, pass through
holes in the insulating slab or board on which the apparatus is mounted and embrace
or otherwise inake contact respectively with the six aforementioned contact pieces a, bc, d,
e and which are mounted at the back of the slab or board. When the lay shaft is
moved into the "off" position the six contacts are broken and the metallic
pieces a 1, 61, c1, d 1, e 1 and 1 which are now not in contact with any source. of
electro-motive force can he touched with impunity by the operator.
While the switch is in this "off" position a safety fuse h which is enclosed in a
suitable insulating case is inserted between the metallic pieces 1 and c 1 and a similar
fuse h between 1 and e 1, the metallic ends of the fuse case being pushed into the
slots shown in Fig. 3.
At the same time if the switch is to be used for its ordinary purpose a metallic

page_text: coupling bar suitably insulated is inserted between the metallic pieces a 1 and bl.,
and a similar bar k between e 1 and f1, the metallic ends of the insulated bar being
pushed into the slots m shown in Fig. 3.
C
It will be seen that if the switch be now moved into the "on" position the current
will flow from the positive source of supply a through the fuse between c 1 and b1
then through the coupling bar & between 1 and a 1, to the contact piece a which is
the commencement of the distributing circuit. After passing round the outside circuit
the current will return to through the coupling bark between 1 and el then
through the fuse between e 1 and d I and back to the negative source of supply connected
with the contact piece d.
The safety fuses and coupling bars are arranged so that they can be quickly and
easily attached or detached when the switch is in the "off" position but cannot possibly
be attached or detached when the switch is in the "on" position without first opening
the switch.
The whole of the metallic parts of the apparatus which remain on the front of the
board when the switch is in the ,,
012 position and which are then in contact with a
source of electro-motive force are carefully insulated and arranged so that they cannot
possibly be touched and since all the metallic parts of the apparatus which when the
switch is in the "off" position are in connection with a source of electro-motive force
are at the back of the board and removed from the operator it will be seen that all the
operations can be conducted with absolute safety.
The above described apparatus is practically a double-pole, double-break switch
combined with a double-pole fuse and is intended for connecting or disconnecting one
source of supply and one distributing circuit.
When there is more than one source of supply or more than one distributing
circuit and where these sources of supply and circuits are required to be coupled in
parallel one of the above described switches is used for every source of supply and
one for every distributing circuit-In this case the switches are generally arranged
side by side with the contact pieces a b c d e and f in a vertical straight line. The
contact pieces a in all the various switches are permanently coupled together at the back
of the board as also are-all the contact pieces fas shown by the dotted line in Fig. 1.
In the switches connected with the source of supply c and d are coupled respectively
to the positive and negative pole of each dynamo, accumulator or other source of.
supply but in the switches connected with the distributing circuits c and d are coupled
respectively to the positive and negative lead of the circuit they govern.
It will be seen that any source of supply or any circuit can be switched in or
out at will to the two parallel conductors to which respectively are permanently
attached all the a contacts and all the f contacts.
When however it is desired to cross couple any particular dynamo or source of
supply with any particular circuit independent of the usual parallel arrangement
the particular supply and circuit switclics are both moved into the "off" position
when the coupling bars & between a 1 and 61, and between e 1 and f1 are removed
from both switches. At the same time the contact pieces in each of the two
switches are coupled by means of flexible conductors, as also are the contact
pieces e in each of the two switches-The switch being in the "off" position this
can safely be done since the contact pieces and are not then connected with
any source of electro-motive force. The switches are then moved into the "on"
position when the desired source of supply and distributing circuit will be coupled
together direct and independent of the ordinary parallel arrangement-The switch
is so constructed that it is impossible to couple or uncouple the flexible cross
coupling except when the switch is in the "off" position.
Having now particularly described and ascertained the nature of our said Inven-
tion and in what manner the same is to be performed we déclare that what
we claim is :-
1. In switches for the making and breaking of circuits conveying electric currents
the method of so making the fuse form part of the switch that when the switch is

page_text: open the fuse is entirely removed from all sources of electro motive force and can
consequently be safely and easily removed or renewed substantially as described in
this specification and shown in the drawings.
2. In combined switches and fuses of the type and for the purposes described in
this specification the method of arranging all the metallic parts which are permanently
in connection with a source of electro motive force at the back of the board and
removed from the operator so that they are not easily accessible even when the switch
is in the "off" position and of so insulating those metallic parts of the switch and
fuso which remain on the front of the board and are in connection with a source of
electro-motive force when the switch is in the on position that they cannot be
touched substantially as and for the purposes described.
3. The main distributing switch and fuse board as a whole substantially as described
in this specification and sliown in the drawings.
Dated this 23rd day of September 1889
CHARLES MARK DORMAN.
REGINALD ARTHUR SMITH.