AN ELECTRIC LIGHT SWITCH
Year: 1885

page_text: ANDREAS PETER LUNDBERG 18 Regina Road Tollington Park London N Electric
Light Fitting Manufacturer do hereby declare the nature of my Invention for
AN ELECTRIC LIGHT SWITCH to be as follows:-
The invention is an improvement on a Switch designed by me in the year 1883,
and consists chiefly in the more efficient application of a spring F, which is
more fully described by means of drawings, and description in writing sent
herewith.
My invention relates to that branch of electric light fittings known as switches.
In Switches hitherto made, some difficulty has been experienced in obtaining a
perfect contact, and at the same time a decided ON or OFF action, when making
or breaking the contact; particularly the latter, as when breaking contact sparking
more or less takes place, in proportion to the strength of the current.
.
In my Switch hereinafter described good contact, and decided ON or OFF
action is secured, and the sparking when breaking contact occurs in a place where
no damage is done to the Switch.
Same letters in all the drawings refer to the same parts.
(A) is a base plate made of any insulating material on which the other parts of
the Switch are mounted,
(B) is the connecting piece or plate which makes or breaks the circuit between C
& D though which the current is flowing.
(C) is a contact plate, through the centre of which B, the connecting piece
works.
(D) is a section of a brass ring divided at J and again connected by means of a
lead or other suitable fusible metal wire, clamped under the screws m m³ to form a
safety junction in the circuit.
(S) is a thin, flat & bent brass spring fixed on to D, and is slightly overlapping
it The principal use of the spring S is to make the last contact between the
plate B, and segment D, this useful application is obvious:-Viz, the sparking
which always occurs when breaking contact takes place here between the upper
part of the plate B, and the lower part of the spring S, thereby preserving the real
contact; viz, between the upper parts of the surfaces of C & D, and the lower face
of B-The elevation of this spring S is shewn by Fig. 8.
(F) is a metal spring preferably of hardened steel, and spiral shaped; stretched
between a fixed point E and a moveable pin H.

page_text: (H) is a pin fixed to the contact plate B & moving with it-The action of the
spring F which is fixed between the two points E & й, is the means by which the
decided "ON" & "OFF" action is secured-The action of the spring F, may be
best & most simply explained by means of a diagram-Fig. 7 is an inverted
pendulum P standing on its centre O, the pendulum when left to itself would
naturally by the slightest touch fall over to one side, or the other, against the pins X
or Y-A somewhat similar action takes place in the Switch where the tension of
the spring F, performs the same part as the "bob " of the inverted pendulum.
(J) is the safety junction between D & D¹.
"
(K) is the key or handle by which the Switch is turned "ON" or OF," & to
this key is fixed the connecting plate B.
(T T¹) are the terminal screws.
(L) shows the cover of the switch.
Fig. I. Shows the plan, & position of Switch when ON.
Fig. IV. Do.
"
"
Do.
"
"
OFF.
"
Fig. II. Shows the section of the Switch at X, Y.
Fig. 3. Shows the plan of the under side of the base A. & position of spring F,
when the Switch is "ON."
Fig. 5. Shews the Switch with its cover on- -The key K is marked with two
arrows one running to the right marked ON, & another to the left marked OFF,
they indicate the direction the key must be turned for to make or break the
contact or circuit.
.
Fig. 6. Shows the section at Y, X, but only the base-plate, the cover & the
key-block.
The invention for which I now solicit a Patent is an improvement on a switch
designed by me in the year 1883, and consists chiefly in the more efficient applica-
tion of the spring F as described above-The spring F, in the new switch is now
placed in such a manner that it acts with a downward pulling action pressing the
contact plate B on to the contact surfaces C, D, and thereby securing a very good
rubbing contact, and at the same time performing that tumbling movement of the
contact plate B (described by the diagram Fig. 7.) whereby the decided ON &
OFF, action is produced.
The spring F, as shown on the drawing is placed below on the base A, but I do
not confine myself by placing it in that position as the same efficiency may be
obtained by placing the spring above on the base A.

page_text: ANDREAS PETER LUNDBERG 18 Regina Road Tollington Park London N. Electric
Light Fitting Manufacturer I Andreas Peter Lundberg do hereby declare the
nature of my invention for AN ELECTRIC LIGHT SWITCH, and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
In switches hitherto made, some difficulty has been experienced in obtaining a
perfect contact, and at the same time a decided "On" or "Off" action when making
and breaking contact, particularly the latter as when breaking contact sparking
more or less takes place, owing to self-induction of the current in proportion to its
strength,
In my switch hereafter described good contact and decided "ON" or "OFF"
action is secured, and the sparking occurs in a place where no damage is done to
the switch. The novelty in the present switch which I claim as my invention,
consists of an improvement which I have made in a switch invented by me in the
year 1883 and now well-known among Electric Light Engineers as the Lundberg
Electric Light Switch.
For the description I beg here to refer to the drawings sent with my application
for provisional protection No 2162 dated February 17th 1885.
The same letters in all the drawings refer to the same parts.
(A) is a base made of any insulating material on which the other parts of the
switch are mounted.
(B) is the connecting piece or plate which makes or breaks the circuit between C
& D through which the current is flowing.
(C) is a contact plate, through the centre of which B the connecting piece
works,
(D) is a section of a brass ring divided at J to allow a lead, or other suitable
fusible metal wire, to be placed between D and the broken off part D¹, by means of
the two screws M M¹ to form a safety junction in the circuit, melting and
thereby breaking the circuit, in case the current passing through the circuit is too
strong.
(S) is a thin flat bent brass spring fixed on to D and slightly overlapping it.
The principal use of the spring S is to make the last contact between the plate B
and the segment D, the importance of this application viz:-the sparking, which
always occurs when breaking contact, takes place here, between the upper part
of the plate B, and the lower part of the spring S, thereby preserving the real con-
tact viz:-between the upper parts of the surfaces C & D and the lower face
of B-The elevation of this spring S is shewn by fig. 8.
(F) is a metal spring preferably of hardened steel and spiral shaped, stretched
between a fixed point E, and a moveable point H.
(H) is a pin fixed to the contact plate B and moving with it. The action of the
spring F may be best and most simply explained by means of a diagram. Fig. 7
is an inverted pendulum P, standing on its centre O, the pendulum when left to
itself, would naturally by the slightest touch, fall over to one side or the other,

page_text: against the pins x or y. A somewhat similar action takes place in the switch,
where the tension of the spring F performs the same office as the bob of the
pendulum.
J is the safety junction between D & D¹.
Kis the key or handle by which the switch is turned "ON" or "OFF" and to
this key is fixed the connecting plate B.
T&T are the terminals.
L shews the cover of the switch which is made of various designs and material.
Fig. 1. Shews the plan and position of the switch when "ON."
Fig. 4. Shews the plan and position of the switch when off.
Fig. 2. Shews the section of the switch at x y.
Fig. 3 Shews the plan of the underside of the base A, and the position of the
spring F when the switch is "on."
arrows
Fig. 5. Shews the switch with its cover on- -The key K is marked by two
one running to the right marked "ON" and one running to the
left marked "OFF," by which means they indicate, which way the key must be
turned to make or break circuit.
Fig. 6. Shews the section at x y, but only the base plate, the cover, and the
key-block.
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
Chiefly the placing of the spring F (fig. 2.) in such a position, either above or
below the moving contact plate B Figs. 1. 2. & 4. so as to give it, the plate B, a
downward pressure, as well as a side. movement, and by that means secure a
rubbing, clean, and sure contact which is very essential in a switch.
The improved action of the said spring is best shewn in Fig. 2. A spiral spring
is here placed in a cavity under the base plate A; stretched on and between two
pins E&H, The pin E is a fixture to the base plate A, and the pin H, passing
through a circular slot in the base plate A, is fixed into the moveable contact
plate B-The spring F will here act as a lever on the pin H, and exert a down-
ward pressure on the contact plate B against the contact pieces C & D Figs. 1. 4,
This downward pressure will always tend to preserve a clean contact between the
conducting metal picces, so that the more they are used the better the contact
will become.
Dated this 6th day of November 1885