Improvements in Electric Light Switches.
Year: 1899

page_text: Date of Application, 28th Dec., 1899
Improvements in Electric Light Switches.
ANDREAS PETER LUNDBERG and GUSTAF CHARLES LUNDBERG, both of Bradbury
Electrical Works, Bradbury Street, Kingsland, London, N., Electrical Engineers,
do hereby declare the nature of this invention to be as follows:-
Our invention relates more particularly to that class of electric light switches
known as two-way switches, which enable circuits to be controlled from two
points, usually for staircase or corridor lighting.
We take a base of porcelain, or other insulating material, and in it form a
suitably shaped well or recess, round the top of this recess suitable arrangements
are made for inserting either flat or spiral springs which can be manipulated by
means of a centre piece working within the recess, and so form the necessary
power for working the switch and determining right-angle movement of the key
Round the top of this recess we also arrange holes for fixing the metal contact
pieces to the base and also for the three wires to enter their terminals.
The metal contact pieces are so arranged that the switch works by a forward
and backward movement of the key, one of the metal contact pieces being
provided with spring contact jaws at both ends and so forming the common
terminal required in a two-way switch. A thumb key of the usual shape is
employed for actuating the switch, but embedded within it is a spring movement
working either way, which is capable of producing spring independent quick
make and break of the two circuits controlled by the switch. Loosely attached to
the key piece is a bridge contact plate which connects alternately the two circuits.
On this contact plate four pins, or a properly shaped piece, are provided, for
working between the flat or spiral springs previously referred to, within the
recess, for determining the right-angle movement.
.6
The switch possesses double quick make or break of the circuit on either
way" and allows the current to pass directly from contact to contact without
the use of a common bearing plate, as usually employed in two-way switches, and
which, owing to the possibility of working loose. is often the cause of heating
between the bearing plates & faulty working of the switch.
1
1000
ANDREAS PETER LUNDBERG.
GUSTAF CHARLES LUNDBERG.

page_text: Middlesex, Electrical Engineers, 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:--
Our invention relates more particularly to that class of electric light switches
known as two way switches, which enable circuits to be controlled from two
points, usually for staircase or corridor lighting.
And in order that our invention may be thoroughly understood, we now
proceed to describe the accompanying drawing thereof, reference being had to
letters and figures marked thereon..
Fig. 1, is a plan of the top of the switch.
Fig. 2, is an elevation..
34'
Fig. 3, is a view of the switch with the cover n removed.
Fig. 4, is a part in elevation and part in section of the base, centre piece or
screw and other parts of mechanism.
Fig. 5, is a plan of the bridge contact plate, screwed pins and coil spring.
Fig. 6, is a vertical section on line A, B.
Fig. 7, is a front elevation of the key.
Fig. 8, is a side elevation of the key.
..5
Fig. 9, is a view of the bridge contact plate ; screwed pins n coil spring i flat
spring, and the insulated disc k in section.
Fig. 10, is a plan of the flat springs when the ends of the pins are forced
in to the position shewn.
Fig. 11, is a plan of the underside of the key d shewing the openings o in
which the ends of the coil spring i pass through in order to form the spring.
movement.
Fig: 12, is a plan of the flat springs ¹, placed in the recesses and well m of
base a, before the pins n are fitted thereto.
We take a base a of porcelain, or other insulating material, and in it form a
suitably shaped well or recess b, round the top of this recess b suitable arrange-
ments are made for inserting either flat or spiral springs which can be manipu-
lated by means of a centre piece c working within the recess and so form the
necessary power for working the switch and determining right-angle movement
of the key d.
Round the top of this recess we also arrange holes for fixing the metal contact
pieces e to-the base a 'and also for the three wires to enter their terminals f
The metal contact pieces e are so arranged that the switch works by a forward
and backward movement of the key d, one of the metal contact pieces e being
provided with spring contact jaws g at both ends and so forming the common
terminal required in a two way switch.
A thumb key h of the usual shape is employed for actuating the switch, but
embedded within it is a spring movement i working either way, which is capable
of producing spring independent quick make and break of the two circuits
controlled by the switch. Loosely attached to the key piece is a bridge contact
plate which connects alternately the two circuits.
In the contact plate j four pins are screwed in so that the screwed ends
project above the plate and the plain ends project below the plate j. The
object of the projecting pins above the plate is to receive a coil spring i with
projecting ends which said ends work in the openings o when the key d is
attached to the base a by the screw c or centre piece. The plain ends of the
pins n are for fitting in between the flat springs (previously referred to) within
recesses cut in the recess or well m, for determining the right-angle movement.
A disc or washer k of insulating material is placed below the bridge contact plate.
The end of the vertical centre piece or screw c screws into the block q placed
in the hole r in the key and is secured by a set screw s.
<<
The switch possesses double quick make or break of the circuit on either
"and allows the current to pass directly from contact to contact without
the use of a common bearing plate, as usually employed in. two way switches and
way

page_text: which, owing to the possibility of working loose, is often the cause of heating
between the bearing plates and faulty working of the switch.
The method can be employed in reversing and change over switches, in which
case four similar terminal plates are employed, two separate ones replacing the
double ended one.
The well or recess is adapted for high voltage as the circuit is broken in two
places.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:-
1. The electric light switch substantially as above described in this specifica-
tion and illustrated in the accompanying drawing.
2. In electric light switches, the combination and arrangement of the indepen-
dent spring action both right and left, the bridging contact plate which allows
no current to pass through any pivot, and the double ended spring contact jaws
on contact plates, substantially as herein described and according to the
accompanying drawing.
3. In electric light switches the combination and arrangement of the well m,
recesses 1, recess b, and base a, substantially as herein described and according to
the accompanying drawing.
Dated this 26th day of September 1900
J. P. BAYLY,
18, Fulham Place, London, W.,
Agent for the Applicants.