Improvements in Electric Switches.
Year: 1891

page_text: Date of Application, 24th Mar., 1891-Accepted, 25th Apr., 1891
WELLI
COMPLETE SPECIFICATION.
Improvements in Electric Switches.
CESTER
A communication from abroad by WILLING & VIOLET, of 12, Currystrasse,
Berlin, S.E., in the Empire of Germany, Electricians.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street,
Manchester, both in the County of Lancaster, and 323, High Holborn, in the
County of Middlesex, Civil 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 :-
This invention has for its object a device for instantaneously opening and closing
electric circuits, and is so designed that, on the closing lever being actuated,
potential energy is first stored up, which, on the release of an arresting device, is
transformed into kinetic energy and thereby causes an instantaneous opening and
closing of the circuit.
:-
This invention is shown in the accompanying drawings, in which :-
Figure 1 is a front elevation of the instantaneous closing device attached to an
incandescent lamp,
Figure 2 a side view of the same.
The device can, however, be employed for any other suitable purpose besides
incandescent lamps. B is a frame fastened to the bottom plate A of the incan-
descent lamp holder, in which frame a rotatable pin s, having a handle, is mounted.
A metal bush c is mounted on this pin at one end, and, approximately in the
middle, a loosely revolvable closing lever d. Near to the other end, a releasing
lever bis mounted on the rotatable pins and is secured thereto. It has two
arms 61 and 62 at about an angle of 90°, and is retained in its place by means of
the washer e.
Between the closing lever d and the releasing lever b on the rotatable pins, a
spiral spring a is placed, one end of which is connected to the closing lever d and
the other end to the releasing lever b.
Both the closing lever d and releasing lever b are retained in their places on
the rotatable pin by means of the metal bush c, the spiral spring a, the washer e
and the frame B.
A metal pin v passes transversely through the closing lever d near its free end,
and is preferably surrounded with an insulating sleeve v¹. The said metal pin, in
one position of the device, rests between two spring contact plates w and w', which
are inserted in the circuit which is to be opened or closed.
The releasing lever b is controlled on the one hand in the usual manner by means
of a spring O acting on its projection o. On the other hand, however, it actuates a
plate spring fastened on the frame B; this check spring produces the tension of
the spiral spring a, and thereby the instantaneous opening and closing of the current
circuit. This is alternately influenced by the two arms b' and 62 of the releasing
lever b. When in its uninfluenced position, it is nearest to the pins and retains the
closing lever d, either when the circuit is opened or closed, till it is caught by
one of the arms of the releasing lever b and forced further from the rotatable
pin s.
The mode of action is as follows:-
If the pin s be rotated when the circuit is open, the spring f retains the closing
lever d for a sufficient time until the spring is removed further from the pivotal
pins, by means of the shank 63 of the releasing lever b.
As, however, one end of the spiral spring a is fastened to the closing lever, and
the other and to the relancing lovon the
Ja haine hal
L
1

page_text: rotates, the spiral spring is put in a state of tension during the rotating of the
pivotal pin.
The
The spring is then forced down corresponding to the curve described by the
shank, thus releasing the closing lever d at a given moment, whereby the
potential energy is changed into kinetic. In this way, the closing lever d, with its
metal pin v, is suddenly jerked between the two contact plates w and w¹.
process is a similar one for opening the circuit; on the turning of the pins, the
spring is first released and retains the closing lever d in its position for a sufficient
time to allow of its being bent outwards again by the other lever b. The breaking
of the circuit is performed as instantaneously as was the closing of the same,
described above.
This device has a great technical superiority over all existing closing devices,
because, with an absolute security of working, can not only be produced cheaply,
but it further exhibits important advantages. In addition to closing and opening:
the circuit instantaneously, this advantage is obtained that the principal part
(namely, the spiral spring) of the device remains almost always in a normal or
quiescent condition, as it is put in tension only during the brief rotation of the pin
before the opening or closing of the circuit, and it is released immediately after the
opening or closing of the same.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondents, I declare that what I claim is :-
1. An instantaneously operating electric switch, having a contact lever d
mounted loosely upon the rotatable switch pin s, a releasing lever b fixed rigidly to
said pin and a spiral spring a interposed between said levers and having its ends
connected respectively therewith, the arms of said releasing lever being arranged
to operate a check or detent device which retains the contact lever d for a suitable
period during the movement of the switch pin and thereby causes the spiral spring
to be put in a state of tension, whereby an instantaneous opening or closing of the
circuit is effected by the spring, and the latter is only placed in a state of tension
just prior to said opening or closing, being immediately after restored to its normal
or quiescent condition, substantially as described.
2. In an instantaneously operating switch of the kind described, the detent
device consisting of a flat spring which detains the contact lever d during the first
portion of the rotation of the switch pin s and is then forced out of its normal.
position by one or other of the arms of the releasing lever and thereby effects
the instantaneous release of the contact lever, substantially as described.
=-
Dated this 23rd day of March 1891.
WM. P. THOMPSON & Co.,
Agents for the Applicant.