Improvement in Electrical Switches and other Electrical Apparatus.
Year: 1890

page_text: Date of Application, 15th Nov., 1890
Complete Specification Left, 9th Dec., 1890-Accepted. 7th Feb
1801
PROVISIONAL SPECIFICATION.
Improvement in Electrical Switches and other Electrical Apparatus.
LUIS ALWYN DAVIES 9 Scarsdale Terrace Kensington London W. Electrical
Engineer do hereby declare the nature of this invention to be as follows:-
The use of buckled metal plates for causing an instantaneous make or break of
electrical contacts in electrical switches and other electrical apparatus.
Dated this 14th day of November 1890.
COMPLETE SPECIFICATION.
Improvement in Electrical Switches and other Electrical Apparatus.
I, LUIS ALWYN DAVIES, of 9, Scarsdale Terrace, Kensington, in the County of
London, Gentleman, 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 :-
My invention relates to an improved electrical switch or contact device, and
consists in the use of a concavo-convex thin plate of metal adapted to act as a spring
in the manner hereinafter more particularly described.
To enable my invention to be fully understood I will describe the same by
reference to the accompanying drawing, in which:
Figures 1 and 2 are respectively front and side views of an electrical switch
or contact device constructed according to my invention.
Figure 3 is a central vertical section of the same shewing the parts in the
position they occupy when the circuit is broken; and,
Figure 4 is a similar view shewing the parts in position when the circuit is
closed.
Figure 5 is a view of the switch or contact device, with the front part of the case
and the buckled plate removed..
Figures 6 and 7 are respectively rear and side views of the buckled plate with its
operating push-piece.
a, b represent the front and rear parts of the case of the switch which, as repre-
sented in Figures 3 and 4, are connected together by means of screw-threads in a
usual manner; and the rear part of the case is adapted to be screwed to a wall or
switch-board or the like.
c, d indicate the terminals of the electrical circuit which, as represented in
Figure 5, are in the form of a metal ring and disc respectively but may be of other
suitable form.
e represents my concavo-convex spring metal plate which is shewn located in a
recess in the part a of the case in such a manner that its edge is always in contact
with the terminal c. To my said spring plate is connected a push-piece fin such a
manner that, when the latter is pushed inwards, (the plate being in the position
hewn in Figure 3) the said plate will be caused to bend or buckle inwardly into
he position shewn in Figure 4, 50 as to be brought against the terminal d and
hereby complete the electric circuit.
To break the circuit or contact it is only necessary to move or pull the push-
iece in the opposite direction to that hereinbefore described, so as to cause it to
gain take the position shewn in Figure 3.
It will be obvious that my concavo-convex buckling plate will act as a spring
that it will automatically retain either of the two positions in which it is
laced.

page_text: Where a relatively long pull is required such for example as when the switch or
contact device is to be used for currents of high electro-motive force I can employ
two or more buckling plates in combination. My buckling plate may be made
corrugated and if found desirable means may be provided for moving it circum-
ferentially to obtain a rubbing contact.
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 :-
1. An electrical switch or contact device having a metal spring adapted to be
bent or buckled to make or break the contact, and to automatically maintain either
of the two positions into which it is moved, substantially as described.
2. In an electric switch or contact device the employment of a spring metal plate
of concavo-convex shape, adapted to be buckled by means of a push piece so as to
move it into or out of contact with the circuit terminals, substantially as described.
3. The manufacture and use of the improved electrical switch or contact device
herein before described and illustrated in the accompanying drawing.
1 1
1000
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.