Electric Switches.
Year: 1890

page_text: Date of Application, 17th May, 1890
Complete Specification Left, 12th Feb., 1891-Accepted, 14th Mar., 1891
PROVISIONAL SPECIFICATION.
Electric Switches.
We, CHARLES EBENEZER CHALLIS, of No. 30, Navarino Road, London, N.E.,
Machinist, and GEORGE GRAHAM, of No. 26, Montague Road, Victoria Park,
London, N.E., Brassfinisher, do hereby declare the nature of this invention to be
as follows:
د"
We lessen the sparking ordinarily taking place at making contact, and eliminate
the danger of the switches being left "half on by causing the contact to be made
by a "fly-on" movement, and broken by a fly-off" which are practically
instantaneous.
<<
,,
In our single break switches we lock the contact bar " on and "off" by a stud
upon it which works round an arc or circle upon the lower plate; the stud is forced
into hollows or notches in the arc by a spring, and is lifted out by a cam fixed to
the handle; a spring is placed between the handle and the contact bar so that the
handle on being turned round compresses (or extends) the spring until the cam has
lifted the stud out of the notch, when the accumulated force causes the bar to
immediately "fly-on" and the stud to engage the next notch.
To break contact the handle is turned in the opposite direction, the spring is
thereby compressed (or extended) until the cam has thrust the stud out of the
notch, and until the force accumulated in the spring overcomes the frictional
resistance of the contact, when the bar will immediately "fly-off."
Double and multiple break switches are made in a practically similar manner to
that above described.
"
We also obtain a "fly on and "fly-off" movement, without locking, by causing.
the contact bar to be operated by a spring upon the handle which is compressed (or
extended) until the force overcomes the frictional resistance of the contact or the
rest."
"
Dated this 17th day of May 1890
C. E. CHALLIS.
GEORGE GRAHAM.
COMPLETE SPECIFICATION.
Electric Switches.
We, CHARLES EBENEZER CHALLIS, of No. 30, Navarino Road, London, N.E.,
Machinist, and GEORGE GRAHAM, of No. 26, Montague Road, Victoria Park,
London, N.E., Brassfinisher, 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 :-
Our invention relates to the construction of electric switches in such a manner as
to lessen the sparking at the contacts, and to avoid the risk of leaving the switch
half on, by causing the contact to be made and broken by a "fly on " and a "fly off"
movement, practically instantaneous, as we shall describe referring to the accom-
panying drawings.
Fig 1 is a section of the cap and elevation of the base and interior parts of a
switch according to our invention.
Fig 2 is a plan on X X.
The button or knob A. of insulating material is fixed on an axis which is centred
in the base B of insulating material, on which base is screwed the cap C. On the
base B are fixed two contact plates D having their ends sloped.

page_text: A bent metal bar E (when its ends bear on the plates D) forms a conductor from
the one to the other, the switch being then "on."
When the bar E is turned about one quarter round, s
so that its ends are not in
contact with the plates D, the switch is "off." The bar E has in its middle a
slotted hole through which passes the axis a so that E can not only turn on a but
can also slide a little to the left.
1
}
Under the bar E there is fixed on the "base B a plate or disc F which has two
notches ff either of which can receive a tooth or stud projecting down from the
bar E. Also from the bar. E two walls 'e el project upwards. To the knob A.is
attached a wall H projecting downwards, this wall being of eccentric form, its face
being farther from the axis a at each end than it is at the middle.
Around the axis a is wound an elastic wire K in several convolutions, its ends k k¹
bearing against the edges of the walls e e¹ respectively, and between those ends of
the wire a wall L. projects down from 'A.
Now on turning the button A in the direction of the arrow, the wall L pushing
against the branch of the wire spring, strains the spring, so that its k branch
bearing against e urges the bar E to turn, but this it cannot do because its tooth is
engaged in the notch f. But by turning A the wall H, owing to its eccentric form,
pushes E towards the left and withdraws its tooth from f, and as soon as the tooth
is out of the notch the force of the spring k acting on e causes the bar E to make a
rapid stroke until its tooth comes to face the notch f¹, when, owing to the pressure
of the spring branches kk against e e¹ the tooth of E is forced into the notch f'1
and thus the bar E is held in the "off" position.
In a similar way by turning A. in the opposite direction the bar E is caused to
make a rapid movement to the "on" position shewn in the drawings.
"
66
Although we have shewn in the drawings a switch that has its contact bar E
arranged to take only two positions "on" and "off" in respect of a single pair of
contact plates, it is obvious that by providing several pairs of notches such as ff'
and fixing on the base B a corresponding number of pairs of opposite contact plates
such as D, the contact bar might be made to spring "" on or off"
any pair of
these contact plates, the switch thus acting as a multiple-way switch. In some
cases, such a multiple way switch may be arranged to have no "off" positions for
the contact bar which would then merely spring off one pair of contacts on to another
pair.
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same. is to be performed, we declare that what we
claim is
An electric switch constructed and operating substantially as described with
reference to the accompanying drawings.
Dated this 12th day of February 1891.
ABEL & IMRAY,
Agents for the Applicants.