An Improved Bell Pull" Electric Light Switch.
Year: 1887

page_text: Date of Application, 21st Oct., 1887
Complete Left, 3rd May, 1888
Complete Accepted, 8th June, 1888
66
An Improved Bell Pull" Electric Light Switch.
I ANDREAS PETER LUNDBERG 18, Regina Road Tollington Park, London, N.
Electric Light Fitting Manufacturer do hereby declare the nature of this invention to
be as follows:-
-
This invention relates to an improved form of that kind of Electric Light Switch,
known as "Bell Pull Switches." The object of this invention is to produce a switch
that will make good contact, and quickly "make" or "break"contact, and be
possible by every fresh pull to make and break contact alternately.
To obtain this result, I mount on a base of any insulating material a disc, which is
free to rotate on a centre; and two metallic terminals, rubbing against the circum-
ference of the disc, and so arranged that every alternate quarter of a revolution of
the disc, the metallic contact is made or broken.
The revolving disc has also on its underside four pins, fixed equi-distant from one
another in a circle. A bar free to move vertically is attached to the base under the
disc and pins, this bar has on its upper side a spring catch, which passes freely with
the bar in a downward direction without disturbing the disc, but when moving in
the other direction or upwards, the spring catch on the bar engages with one of the
four pins, and carries the disc round a quarter of a revolution, and the movement of
the bar downwards & upwards will again move the disc through another quarter of a
revolution, by means of the spring catch engaging with the next one of the four
pins, and so on, continually rotating the disc and alternately making and breaking
the contact.
The bar has attached to it a spring which always when left to itself holds the bar
in a fixed position, so that after being pulled down it returns to that position.
The switch can be constructed as a double or single pole switch and to carry either
small or heavy currents.
.
It will be noticed that the disc has no movement during the pulling of the bar
downwards, and stretching of the spring, and that the spring when returning to its
resting place in conjunction with the bar, the spring catch, and either of the four
pins perform the work of moving the disc to make or break contact.
1007
A. P. LUNDBERG,
18, Regina Road, Tollington Park,
London, N.

page_text: H
пет the Sume 15
to be performed, to be particularly described and ascertained in and by the following
statement
This invention relates to an improvement in that class of Electrical Switches,
known as Pull" switches.
These switches are usually constructed so that the contact-making and breaking
arrangements are pulled directly into or out of contact, by the downward pull of a
cord or other device.
By reason of this construction it sometimes happens that the cord is not pulled
quite far enough and the contact pieces are not pulled full home, only a small part of
the surfaces being in contact, but still sufficient to hold them against the action
of the "throw off" springs. This causes the switch to become heated, sufficiently so
sometimes, to set fire to the wood-work, if any be near, or to spoil the mechanism of
the switch, thus rendering the switch unsafe.
The object of my invention is to prevent this occurring and I do this by utilizing
the recoil of a spring, the spring being either compressed or extended, to carry the
contact pieces into or out of contact; the switch mechanism being so arranged as to
prevent the spring coming into action, unless the cord be pulled the proper distance,
then the spring is caused to engage with the making and breaking mechanism and
to carry it full into or full out of contact, thereby ensuring a complete and rapid
make and break. It will be seen that the. contact making and breaking mechanism
can take any form or shape and it can be either rotatory, or moving in a straight
line, or it may be a reciprocating movement. It can be made single or double pole,
or it can be a radial step by step arrangement, for the insertion of resistances or
accumulators; also it can be used in an ordinary hand switch or wherever an
electrical circuit is to be made or broken completely and rapidly, without the possi-
bility of the contact being only partly made or broken. One method of carrying
this out is shown in the accompanying drawings.
Fig. 1 is a plan of the arrangement. Fig. denotes a view of the pull down bar
and a portion in section shewing the interior spiral spring. Fig. 3 is an elevation.
Like letters refer to like parts in each of the figures.
A is an insulating base. C. C are two contact pieces of metal fixed to the base.
D is a metal bar pivotted on I, having fixed to it or part of it and moving with it,
the disc L or its equivalent, L has fixed to its lower surface four pins or catches N;
sliding in or on the insulating base A, is a tube or bar H to one end of which is
fixed one end of the spiral spring K contained within or under the tube or bar H,
the other end of this spring is fixed to the base A; on the upper surface of H is a
spring or other. catch G and an angle piece O which may be either metallic or

page_text: non-metallic and may take any other form, there is also a spring or other catch at G₁
B. B are the terminals for the line wires and J is a ring or other device for attaching
a cord or handle to H; there is also a spring F to press the contact bars into contact
with the contact pieces C. C when in the " on" position.
The action of the apparatus is as follows:-
When H is pulled down to the proper distance thereby stretching the spring K,
the catch G engages with one of the pins or catches N if now H be released, the
spring K will return to its normal position carrying with it, through the medium of
the two catches Gand N the disc Land so carrying the contact bar D out of contact
with the contact pieces, C. C. and vice versa. The movement of the contact bar D is
limited by the catch G and the angle piece O, the catch being so arranged as to
prevent the bar D from moving in a backward direction, and the angle piece o
prevents it from being carried too far forward by reason of the catch or pin at N
impinging against it, when H is in the normal position; it will be seen that the
angle piece is drawn out of the way when H is pulled down. The tube or bar H can
be so arranged that after the ring or handle has been moved a certain distance, H is
disengaged and flies back under the influence of the spring K entirely out of the
control of the operator; but this as mentioned before is only one of the many ways
of applying my invention.
Having now described and illustrated the nature of my invention I claim as new
and novel :-
The application of the recoil of a spring to work the switch mechanism, the spring
to be either under compression or extention the spring having been placed under
compression or extention by the movement of a handle or cord through a fixed
distance, the handle or cord fixed to the moveable bar may move in any direction
i.e. either vertically or horizontally or any given angle. This arrangement being
used to secure a full and complete make or break in an electrical circuit.
Dotad this Third day of Nav 1888
ANDREAS PETER LUNDBERG,
Applicant.