Year: 1897

page_text: Date of Application, 11th Mar., 1897-Accepted, 22nd May, 1897
We, HENRY CHARLES GOVER, Secretary of The Edison and Swan United
Electric Light Company, Limited, CHARLES FARADAY PROCTOR and ALFRED
HEWSON BATE, all of 36 Queen Street, Cannon Street, in the City of London,
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 relates to electrical switches so constructed in combination with
an electromagnet that when the current in the circuit to which the switch is
applied exceeds a certain amount or when a current is transmitted to the electro
magnet the circuit is opened, as we shall describe referring to the accompanying
drawings.
Figure 1 is a front view of a switch, according to this invention, arranged to
operate automatically for opening the circuit.
Figure 2 is a side view shewing the switch in the condition to close the circuit,
and Figure 3 shews it in the condition to open the circuit.
Figure 4 is a section on the line 4-4 of Figure 1.
On a base B of non-conducting material is pivotted a contact lever A, which in
one position as shewn in Figure 2 is engaged between two contact cheeks C and D.
On the lever A is pivotted at a a loaded lever E the extremity e of which as shewn
in Figure 2, is caught under a roller mounted on an adjustable arm of an
armature F which is pivotted on one arm of an electromagnet G. This is wound
with a few coils W of insulated wire forming part of the circuit which is closed
from the post L through D, A, C, a link H, the coil W to the post L'. The
lever A is in form of a fork the prongs of which tend to approach each other but
when pressed somewhat apart and engaged between the cheeks CD make close
contact with them. The pivot at a consists of a pin which where it passes through
the lever E is held by a set screw a' so as to turn with the lever, and one end of
the pin is screwed through a nut a¹ screwed into one of the prongs of A. When the
lever E is turned to the position shewn in Figure 2 this pin working in the nut
forces the prongs somewhat apart so as to make them press the cheeks C, D.
The threads of the pin a and of the nut a' are of different pitch so that by
turning the nut so as to approach nearer to the shoulder of the pin a the pressure
of the prongs A on the cheeks CD can be increased, and conversely. The set
screw a has its end engaged in a hole in the side of the pin a, this hole being
a little slotted so as to allow the end of a³ a little play.
The switch operates in the following manner-When the current exceeds a
certain amount to which the switch is adjusted, the armature F is attracted with-
drawing the roller ƒ and so releasing the lever E which first falls some distance
freely acquiring momentum until the set screw a³ meets the end of the slot in
the pin a; the continued fall of E then turns the pin a relieving the pressure
of the forks of the lever A, on the cheeks CD, and then the tail of the
lever E coming to bear against a pin or roller K as a fulcrum causes movement
of the switch lever A to the position shewn in Figure 3 in which position it is held
by a blade spring M.
By removing the link H connecting the conductors of the circuit which is to be
opened and closed by the switch to the posts L and L³, and connecting the

page_text: conductors of another circuit to L' and L, then the switch is no longer automatic
but can be operated by a current transmitted through the maguet coil W so as to
open the circuit of L L.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, we declare that what we
claim is :-
1. An electrical switch arranged and operating in combination with an
electro magnet, substantially as described with reference to the accompanying
drawings.
2. In an electrical switch the combination of the electro-magnet and its armature,
the loaded catch lever, its screwed fulcrum pin and adjustable nut, the forked
contact lever and the contact cheeks, arranged and operating, substantially as
described.
3. In an electrical switch such as is above referred to the connection of the
switch contacts in circuit with the electro magnet so as to render the operation of
the switch automatic as a cut-out, substantially as described.
Dated this Elevento day or march LOYT.
ABEL & IMRAY,
Agents for the Applicants.
ABEL & IMRAY,
Agents for the Applicants.