Improvements in or relating to Switches for Controlling Electrical Currents.
Year: 1897

page_text: Date of Application, 18th Oct., 1897
Complete Specification Left, 7th July, 1898-Accepted, 27th Aug., 1898
PROVISIONAL SPECIFICATION.
Improvements in or relating to Switches for Controlling Electrical
Currents.
We, JAMES BOOTH. of Cheapside Works, Birmingham, Manufacturer, and
SAMUEL HOBDAY, of Charlton Buildings, Great Colmore Street, Birmingham
Electrician, do hereby declare the nature of our said invention to be as follows:
-
This invention relates to the construction of a switch or apparatus to be
employed for opening and closing the electric circuit or controlling an electrical
current, and in such a manner that the action is rapid and certain, to be explained
by the following description.
The electrical switch has a base usually in the form of a thick disc of non-com-
bustible material, which material is also a non-conductor of electricity, this we
call the insulator disc or base disc.
Two spring contact plungers are provided opposite each other, these pass
through the insulator disc. The central or axial lines of each of these spring con-
tact plungers are parallel with the axis of the insulator disc, or base disc of the
switch.
These contact plungers are each provided with a helical spring in a well known
manner and they are attached to the wiring terminals, one contact plunger to
each terminal by metallic fastenings.
A hole is bored axially through the centre of the insulator or base disc and
through this hole passes axially a pin which we call the action pin, this pin is
considerably longer than the thickness of the insulator or base disc. So that when
the switch is put together it projects considerably above the insulator disc.
To the end of the action pin which projects above the insulator or base disc of
the switch is attached the handle.
A disc of metal which we call the contact disc is secured axially on the action
pin and it projects annularly around it.
Above the contact disc, another disc of larger diameter is also secured axially
to the action pin.
This we call the insulating disc it being made of ebonite or some similar sub-
stance which is a non-conductor of electricity.
The action pin with its. discs can be partially rotated by means of the handle.
The axial hole through the insulator forming a guide for it.
A helical spring is
provided which surrounds the action pin, hetween the insulator or disc base, and
the contact disc this we call the central helical spring.
The tendency of this spring which is fitted between the insulator and the contact
disc is to keep the action pin up and also to keep the contact disc up, and away
from the spring contact plungers, the tops of which are below the contact disc.
A cross pin fixed in the bottom of the action pin prevents (by means to be
described) the action pin from being forced too high and it thus determines the

page_text: height at which the contact disc shall stand above the tops of the spring contact
plungers when the switch is "off" that is open.
The means by which the cross-pin at the bottom of the action pin limits the
tendency of the action pin to rise under the influence of central helical spring
under the contact plate is as follows;-
In the centre of the underside of the insulator or disc base, there is a recess of the
shape of two equal and opposite segments of a circle.
The angular size of these segments limits the angular movement of rotation of
the action pin, the crosspin of which moves in the double segmental recesses. Each
of these segmental recesses has its surface inclined in the same direction so that
when the action pin is partially rotated by means of its handle on the top, it is
drawn down against the action of the central helical spring. When the pin is
partially rotated in the opposite direction it rises until the crosspin gets to the top
of the incline when its progress is arrested as the crosspin cannot rise higher than
the segmental recesses in the bottom of the insulator.
The action of the switch is as follows:-It is presumed that the wires which
convey the electric current are affixed (by screws provided for that purpose) to the
terminals with which the spring contact plungers are in electrical contact. The
contact disc is kept a little way above the spring contact plungers by means of the
central helical spring. No current can then pass, the switch being
off or
i
open."
2:
on."
::
If however the action pin be partially rotated in the proper direction by means
of the handle then the crosspin at the bottom of the action pin will by its action
on the inclined surfaces of the segmental recesses draw down the action pin until
the contact disc on it comes into contact with the spring contact plungers thereby
completing or closing the circuit, the switch is now
The switch would not remain
or closed when the pressure of the hand
on the handle is withdrawn but it would be opened or thrown off by the action of
the central helical spring but just at the end of each segmental incline there is
provided a flat or platform on to which the crosspin rests against a projection or
stop and by which it is retained in the "closed" or on position of the switch.
Dated 18th October 1897.
"
"
"
THOS.
KENDRICK,
50. Cherry Street, Birmingham, Agent.
Improvements in or relating to Switches for Controlling Electrical
Currents.
We, JAMES Boorit, of Cheapside Works, Birmingham, Manufacturer, and
SAMUEL HOBDAY, of Charlton Buildings, Great Colmore Street, Birmingham
Electrician, do hereby declare the nature of our said invention and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement;-
Our invention relates to the construction of a switch apparatus to be employed
for opening and closing the electric circuit or controlling an electrical current,
and in such a manner that the action is rapid and certain.
And in order that our said invention may be particularly described and ascer
tained, reference is hereby made to the accompanying drawings in which similar
letters of reference indicate corresponding parts, in each figure where they occur.

page_text: "
Figure 1 is a view in elevation of an electric switch OIT in its entirely and
constructed according to our invention.
Figure 2 is a view in elevation as Figure 1 but with the electric switch on."
Figure 3 is a view of the handle detached.
Figure 4 is a view of the handle support, and action pin in connection therewith.
Figure 5 is a plan view, bottom of insulator shewing wiring terminals, and
position of action pin when switched
off."
Figure 6 is a view as Figure 5 but shewing position of action pin when switched
on.'
13
Figure is a view of one of the wiring terminals detached.
Figure 8 is a plan view, top of insulator showing spring contact plungers.
Figure 9 is a plan view, bottom of insulator disc.
Figure 10 is a view in elevation as Figure 9.
Figures 11 and 12 are views, plan and elevation respectively of contact disc.
Figure 13 shews the helical spring as employed.
Figure 14 is a view (part in section) of one of the spring contact plungers.
Figure 15 is a view of the case or receptacle in which the said parts combined
and forming the electric switch are enclosed.
is the base of the electric switch formed of a non-combustible material
porcelain by preference being also a non-conductor of electricity this we call the
insulator or base disc. are two spring contact plungers in the recesses
which pass through the insulator disc a, and are opposite to each other. The
central or axial lines of each of these spring contact plungers are parallel with the
axis of the base disc a of the switch, and each contact plunger b. bis provided
with the helical spring 2 and attached to the wiring terminals c, c, by metallic
fastenings which take the wires c¹ c¹.
a is the axial hole through the centre of the insulator or base a through which
is placed the action pin d and is longer than the thickness of the insulator a, and
is provided with the handle e, which is bored to receive the pin d and secured
thereto by a screw.
f is the contact disc which with the insulating disc are both arranged
annularly around the action pin d.
The pin with the discs f and g can be partially rotated by means of e, the axial
hole a forming a guide for it.
h is the central helical spring surrounding the pin d, fitted between a and f
the power of which keeps the contact disc f up and away from the contact
plungers bb. is a cross pin fixed in the bottom of the action pin 7, and deter-
mines the height at which the contact disc f shall stand above the tops of the spring
contact plungers b. b. and when the switch is "off" or open.
The underside of the insulator disc a is provided with a recess. shaped as two
equal and opposite segments of a circle, jj the angular size of which limits the
angular movement of rotation of the pin and the cross pin i, each of these
segmental recesses has its surface inclined in the same direction.
By referring to Figures 1 and 5 it will be seen that the action of switch is as
follows. The action pin d is here raised by the power of the helical spring h
and the cross pin i takes the position shown, no current can now pass as the switch
is now off" or
*
open."
By referring to Figures 2 and 6 which shew the handle partially rotated in the
proper direction, the action pin & descends against the power of the spring h.
until the contact disc f engages the contact plungers bb, the cross pin i will travel
the inclined surfaces of the segments of the jj until reaching the flats or plat-
forms and upon which the cross pin i rests, and against the stops the
current or circuit is now completed and the switch is
on."
We would observe in conclusion that we do not limit ourselves to the exact
form and configuration of parts as shown on the drawings, as we may vary or
modify them without departing from the principle of our said invention.

page_text: Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:-
In Improvements in or relating to switches for controlling electrical currents."
1. The combination, the insulator or base disc a, provided with axial hole a¹ and
recess, shaped as two equal and opposite segments of a circle j j with inclined
surfaces, having flats or platforms with stops the recess b b in a to
receive the spring contact, plungers b, b and the wiring terminals e, c. The action
pin d provided with handle e, and cross pin i, the insulating disc
with con-
tact dise and helical spring h, substantially as and for the purposes herein
before described.
y
2. The general construction, combination and arrangements of parts forming
switches for controlling electrical currents, substantially as herein before described
and illustrated by the drawings.
Dated 7th July 1898.
THOS. KENDRICK,
50, Cherry Street, Birmingham, Agent for Applicants.