Year: 1899

page_text: Date of Application, 11th Jan., 1899
Complete Specification Left, 11th Oct., 1899-Accepted, 11th Nov., 1899
I, FREDERICK PERCY Cox, of 4, IIargreaves Road, Sefton Park, in the City of
Liverpool, Electrician, do hereby declare the nature of this invention to be as
follows:-
:―
This invention relates to means whereby the contacts of a switch are isolated
from one another, and also from the metallic portions of the switch-arm other
than the metallic portions thereof which are adapted to bridge such contacts,
namely, and more especially-from the central or swivel portion of the switch.
As applied to a double-pole rotary switch wherein a wooden switch arm,
pivotted centrally, carries metallic T-ends which bridge two pairs of contacts,
disposed diametrically opposite one another, I arrange upon such switch arm
a curtain or crinoline of porcelain, or other suitable material, which surrounds
the spindle and central metallic portion of the switch, and which also interposes
itself between each pair of contacts. Such curtain preferably takes the form
of an inverted cup or cups which possess a central aperture through which the
switch spindle passes, and two side grooves or notches which fit over and receive
the switch arm. The rim or rims of the cup extend downwards to the bottom.
of the switch box or base, and in some cases may lip into a circular channel or
channels cut in said base. The cup or,curtain thus encloses the central metallic
portion of the switch and prevents it from being used by a high potential as a
stepping-stone between two terminal contacts, and to gain additional length of
surface, the cup may have two or more lips or walls.
The curtain or shield herein described may be employed in different forms
upon switches of different types. Thus upon a blade or chopper switch, the shield
will take the form of a semicircular plate mounted upon the switch arm and
moving with it, such plate being adapted as far as possible to enclose the metallic
spindle and bearing of the switch arm.
Upwardly projecting shields or walls of porcelain, upon the base or bottom of
the switch box, may be used to telescope with or lie alongside the moving cup
or shield.
1
1 11.
101
1
1000
An Improvement in Electrical Switches.
I, FREDERICK PERCY Cox, of 4, Hargreaves Road, Sefton Park, in the City of
Liverpool, Electrician, do hereby declare the nature of this invention, and in
Price 8d.1

page_text: what manner the same is to be performed, to be particularly described and ascer-
tained, in and by the following statement:-
This invention relates to means whereby the contacts of a switch are isolated
from one another, and also from the metallic portions of the switch-arm, other
than the metallic portions thereof which are adapted to bridge such contacts,
namely, and more especially-from the central or swivel portion of the switch.
In the drawings hereto annexed, Figure 1 is a plan, and Figure 2 is a cross-
section, shewing the application of my invention to a double-pole rotary switch,
wherein a wooden switch-arm pivotted centrally carries metallic T-ends which
bridge two pairs of contacts disposed diametrically opposite one another. I
arrange upon the spindle of such switch-arm a curtain or mantle of porcelain
or other suitable material a which surrounds the spindle and central metallic
portion of the switch and which also interposes itself between each pair of con-
tacts. The curtain a takes the form of an inverted cup which posseses a central
aperture through which the switch-spindle passes and two side grooves or notches
which fit over and receive the switch arm. The rim of the cup a is sunk in a
circular channel b cut in the bottom of the switch-box or base. The curtain or
mantle a revolves with the switch arm.
Figure 3 is a plan and Figure 4 a cross-section, shewing the application of
my invention to a single-pole rotary switch. The mantle a hangs upon the
spindle of the switch and dips into a concentric groove & cut in the porcelain or
other base of the switch.
The curtain or mantle above specified encloses the central metallic portion of
the switch, and prevents it from being used by a high potential as a stepping
stone between two terminal contacts. To gain additional length of surface the
mantle may posses two or more lips or walls which may dip into two or more
concentric grooves b.
The curtain or shield herein described may be employed in different forms
upon switches of different types. Thus upon a blade or chopper switch, the shield
will take the form of a semicircular plate mounted upon the switch arm and
moving with it, such plate being adapted as far as possible to enclose the metallic
spindle and bearing of the switch arm.
Upwardly projecting shields or walls of porcelain upon the base or bottom of
the switch box, may be used to telescope with or lie alongside the moving cup
or shield.
1
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:
The employment in connection with electrical switches of a mantle or shield
which moves with the switch tongue or arm and which encloses or isolates the
central metallic portions of the switch from the contact pieces of the latter, sub-
stantially as herein described and illustrated.
Tut 1
11000