Improvements in Switches for Electric Lighting.
Year: 1891

page_text: Date of Application, 24th Oct., 1891
Complete Specification Left, 19th Dec., 1891--Accepted, 19th Mar., 1892
PROVISIONAL SPECIFICATION.
Improvements in Switches for Electric Lighting.
1, ANDREAS PETER LUNDBERG, of 18 Regina Road, Tollington Park, N., in
the County of London, Electrical Engineer, do hereby declare the nature of this
invention to be as follows:-
:-
My invention relates to improvements in switches for electric lighting, with a
double or single quick independent and instantaneous break.
The switch consists of an insulating base (china, slate or any other suitable
material) with a square cavity in the centre. To each of the four sides of this
cavity is attached a bent (right angle) piece of brass for fixing terminals and also
forming a step to assist in making together with the square cavity a quick break of
the current when turning the key hereafter described. Moving in a centre of the
square cavity is a key of insulating material to which is attached a metal plate fixed
with a centre pin and two split pins, to each of the latter is attached a flexible
helical spring which by alternate revolving movements turns the current on or off
by making or breaking the connections with the brass pieces mentioned above. The
switch key only turns in one direction, and a stop is provided to prevent any move-
ment in the opposite direction. An insulated cover is fitted to the base.
This invention is applicable to other class of electric light fittings as follows:-
Double break pull switch with or without cut out with a lever for cord; ceiling
rose to enable the operator to turn the current on or off direct by a pull at the
flexible cord carrying a lamp; a three or four way switch.
It will be understood that the foregoing is given by way of illustration only, and
that the shapes, materials and proportions of the parts for various electric light
fittings may be varied in many ways within the scope of my invention.
Dated this 24th day of October 1891.
J. P. BAYLY,
18, Fulham Place, W., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Switches for Electric Lighting.
I, ANDREAS PETER LUNDBERG, of 18, Regina Road, Tollington Park, in the
County of London, in England, 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:-
My invention relates to improvements in switches for electric lighting with a
double or single independent and instantaneous break.
I attain these objects by the mechanism illustrated in the accompanying drawing
in which :-
Fig. 1 is a plan of the inside with the rose removed;
Fig. 2, is a vertical section;
Fig. 3, is an elevation of the spring ;
Fig. 4, is a plan of the spring;
Fig. 5, is a plan of the underside of the switch when used in combination with a
wall socket;
Fig. 6, is the front of the key ;
Fig. 7, is a vertical section of the key with the base plate broken off for want of

page_text: Fig. 9, is the end elevation of Fig. 8;
Fig. 10, is a plan of the top of the cradle.
Similar letters refer to similar parts throughout the several views.
This switch consists of a base a with a rose c of insulating material (porcelain,
slate, etc.) this base has a square cavity or well recessed in it and in the centre of
this cavity is a small hole which forms a bearing for the centre pin g of the key b
hereafter described.
To each of the four sides of this cavity is fixed a right angle piece of brass 4, one
face overlapping the edge of the cavity and the other fixed to the surface of the.
base of insulating material a; these angle pieces d are used as connecting plates, for
fixing the terminals e of the switch, and also as steps which assist in making in
combination with the helical contact springs i, i, an independent quick "make" and
"break" of the current, when the key b is turned in the proper direction as here-
after described. Revolving in the centre h of the square cavity is a key piece 6 of
insulating material, attached to which is a bent metal plate at of the shape shown
and herein termed a "cradle," provided with a centre bearing pin g and two split
posts j, j, placed radially, each at an equal distance from the centre in a straight
line, to each of these posts is attached a flexible helical metal contact spring i, these
two springs i, i, acting together in combination with the brass steps d, produce a
double independent."make" and "break" of the circuit by alternate quarter of a
circle movements.
.
The helical springs i, i, as they pass over the surface of the contact plates d, are
gradually wound up, and when reaching the edge of the brass pieces d, fly off,
producing a quick independent "make" and "break" of the circuit, preventing the
possibility of any damage being done to the contact plates d or springs i, i, by
sparking
60 obviating the use of the objectionable." loose key" so commonly
used in switches.
The switch key b in Figs. 1, and 2, turns in one direction only and a method of
preventing any back movement is provided.
23
It may be accomplished by putting a stop a³ on the helical springs i, i, which
catches against one of the edges of the cradle a as in Figs. 1, and 2, when the springs
unwind slightly by reason of the back movement wedge against the cradle arresting
any further back movement; and also by means of a screw or stop pin n, as in
Fig. 5, butting up against the helical spring and effecting a similar object.
It will be noticed that the key b is provided near the thumb piece with a bevel
that corresponds with another bevel in the top of the inside of the rose c; these
similar bevels acting in combination with the central pin g of the key and the central
hole in the square cavity form two bearings for the key and produce true central
working.
The switch may be applied in combination with a wall socket as follows :-
The plug is attached to a flexible cord in the usual way, the two split poles of
which fit into the sockets m, through the openings as described by dotted lines in
Fig. 6, in a key k, this said key k, taking the place of the key b in Figs. 1, and 2. The
key is attached to the base plate a by a screw 9 as in Fig. 7, passing through an
insulated tube o; and the springs ii are slipped into the split portions of the poles p p.
Manipulation of the key is similar to that of b when revolving in the square recess.
The sockets m are cast with plates m³ for fixing by screws to the key k. In Fig. 5
the stop a² on the helical spring i catches against stop the pin n.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a switch, the helical contact and operating spring or springs, for the purpose
specified.
2. In a switch, the application of the square carity or recess in the base of the
LI
"

page_text: 3. In a switch, the method of stepping the sides of said cavity or recess, with
brass pieces which accelerate the "make" and "break" of the current, substan-
tially as described.
4. In a switch, the brass shield or cradle to which the helical springs are fixed,
which prevents any back movement of the switch handle, if an attempt is made to
turn it in the wrong direction, for the purpose specified.
5. In a switch, the use of the split posts, fixed in the cradle or shield, round which
the helical contact springs are wound, this cradle being fixed to the key piece by
the central pin screwing into the key piece, substantially as described.
6. In a switch, the right angle brass pieces serving the double purpose of contact.
plates for attaching the terminals of the switch to, and as steps for accelerating the
"make" and "break" of the circuit, substantially as described.
7. In a switch, the combination of the hole in the base, forming one bearing in
which the central pin of the key works, and the corresponding bevels at the top of
the key and inside top of rose, for obtaining true central working of the key in the
hole of the cover, substantially as herein described and according to the accom-
panying drawing.
Dated this 10th day of December 1901
J. P. BAYLY,
18, Fulham Place, W., Agent for the Applicant.