IMPROVEMENTS IN ELECTRIC LIGHT SWITCHES
Year: 1885

page_text: I, NORCLIFFE GEORGE THOMPSON of 4 Queen Victoria Street, London in the
county of Middlesex, Electrical Engineer do hereby declare the nature of my
invention for IMPROVEMENTS IN ELECTRIC LIGHT SWITCHES to be as follows:-
I fix a flat bar of metal with the ends bent up or a channel shaped casting Fig. I a
to a base of wood or other insulating material by means of screws or in some other
suitable manner Fig. I b and bridging across between the ends of the casting or
bent bar is placed a piece of riband steel whalebone or other material having the
required amount of spring Fig. I c.
The bridging spring being longer than the piece supporting it, it will take a bent
form viz either that in which it is shewn or that of the dotted line Fig. I.
It is absolutely impossible for the spring to take any intermediate position.
At right angles to the spring and attached to it is fixed a spindle Fig. I d. which
is guided at its lower end by the insulating base and at its upper by the cover of
the switch through both of which it passes Fig. L
Immediately under the spring and on the spindle is fixed a plug Fig. I e. of brass
or other conducting material.
This plug when the switch is in the position shewn makes electrical connection
between the two halves of a metal ring Figs. I & IIff or between two contact
springs which are fixed to the insulating base and to which the wires of the circuit
are attached.
A handle is fixed to the spindle outside the cover Fig. I g.
The action will be as follows:-By pulling the handle out from the cover the
spring and plug will jump across to the position shewn by the dotted line and
consequently break circuit between the metal pieces ff the sides of the metal.
support a will spring outwards slightly thus facilitating the movement of the spring
and plug and also assisting in making it keep its bow form.

page_text: 2nd Its extreme simplicity and consequent cheapness in construction.
3rd Its suitability for a room switch.
My claims are.
1st The application of a bow spring to form contact.
2nd The bent bar or casting which supports the spring having a slight spring in
itself as applied in the above.
An Improved switch for Electric gung.
I, NORCLIFFE GEORGE THOMPSON, of 4 Queen Victoria Street London, in the 1
county of Middlesex, 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:-
I fix a flat bar of metal with the ends turned up, or a channel shaped casting
Fig. I a to a base of wood or other insulating material by means of screws or in 2
some other suitable manner Fig. I b. and bridging across between the ends of the
casting or bent bar is placed a piece of riband steel, whalebone or other material.
having the required amount of spring Fig. c.
The bridging spring being longer than the piece supporting it, it will take a bent
form, viz: either that in which it is shewn or that of the dotted line Fig. I.
It is absolutely impossible for the spring to take any intermediate position.
At right angles to the spring and attached to it is fixed a spindle Fig. I & III d.
which is guided at its lower end by the insulating base and at its upper by the
cover of the switch through both of which it passes Fig. I.
Immediately under the spring and on the spindle is fixed a plug Fig. I. e. of
brass or other conducting material.
This plug when the switch is in the position shewn makes electrical connection
between the two halves of a metal ring Figs. I II & III f. f. or between two contact
springs which are fixed to the insulating base and to which the wires of the circuit
are attached.
A handle is fixed to the spindle outside the cover Fig. I & III g.
E

page_text: The action will be as follows:-By pulling the handle g. out from the cover
the spring and plug will jumb across to the position shewn by the dotted line and
consequently break circuit between the metal pieces f.f. the sides of the metal
support a. will spring outwards slightly thus facilitating the movement of the
spring and plug and also assisting in making it keep its bow form.
The advantages of my switch are:-
1st Its decided and positive action, it being absolutely impossible to place the
switch in any intermediate position, hence the contact must be well made or
completely broken.
2nd Its extreme simplicity and consequent cheapness in construction.
3rd Its suitability for a room switch.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
1st The application of a spring to maintain the contact plug in either one of two
positions as described.
2nd The method of supporting the above spring by means of the bent bar or
casting having a slight spring in itself as described or by any other sort of support,
to effect the above purpose.