Improvements in Electrical Switches.
Year: 1895

page_text: Date of Application, 12th Dec., 1895-Accepted, 18th Jan.,
1896
Improvements in Electrical Switches.
We, THE EDISON AND SWAN UNITED ELECTRIO LIGHT COMPANY LIMITED-
of No. 100 Victoria Street, Westminster, in the County of London, and CHARLES-
FARADAY PROCTOR, of The Edison & Swan United Electric Light Company's
Works, Ponders End, in the County of Middlesex, Electrician, 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:-
This invention relates to the construction of electrical switches in such a
manner as to secure complete insulation of the terminals from each other when the
circuit is opened.
For this purpose, the switch is constructed as we shall describe referring to the
accompanying drawings.
Fig. 1 is a vertical section and Fig. 2 is a plan of a double pole switch according
to our invention, Fig. 3 is a part section on X X of Fig. 2, the disc being turned
one quarter round.
On a base B of wood or of ceramic or other suitable insulating material is
mounted a spindle S which can be turned by a handle H of insulating material..
This handle has fixed in it a central piu h which projects down through a bearing in
a bridge D and enters a recess in the spindle S free to turn therein to a certain
extent as determined by a cross pin projecting through slots in the upper part of
the spindle S. The lower part of the spindle S has two flat sides against which
bear the limbs of a wire spring W, these springs tending to bring the spindle
always to the position in which the circuit is opened. On a squared part of the
spindle S is clamped by a nut s between asbestos washers a a disc A of ceramic or
other suitable non-conducting material. On this disc are fixed two opposite pairs.
of conducting plates C the one of each pair above the disc metallically connected
to the other below the disc. On the base are fixed two pairs of segments E E
each of which is connected to one of the conducting wires of the circuits. On
each of these segments are fixed a number of bent elastic metal strips F F¹, two-
sets F of these being on the upper sides of the segments E and two sets F' on the
lower sides of the segments E. When the disc A is turned into such a position.
as to bring the plates C between the upper strips F and the lower strips F1 of each
pair then each of the segments E is put in electrical connection with the adjacent E¹
the circuits being thus closed. On turning the handle H, the plates C are first
moved out from between the strips F and F and thereupon the spring W causes.
the spindle S to make a rapid movement, bringing 'the plates C to the position
shewn in Fig. 2 and so opening the circuit. In this position of the parts the upper
and lower strips F and F are effectually insulated from each other by the inter-
position of the non-conducting disc A between them, so that there can be no passage
of current from the one to the other, such as might occur if the space between them.
were open.
Obviously for a single pole switch one set of the segments E E¹ strips F F¹ and
plates C may be dispensed with.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In an electrical switch, mounting the conducting plates on a non-conducting

page_text: disc which, when the switch is turned to open circuit, is interposed between the
terminals, substantially as and for the purpose set forth.
2. An electrical switch constructed and operating substantially as described with
reference to the drawings.
Dated this 19th dox of December 1805
ABEL & IMRAY,
Agents for the Applicants.