.
Year: 1891

page_text: Date of Application, 16th Mar., 1891
Complete Specification Left, 16th Dec., 1891-Accepted, 23rd Jan., 1892
PROVISIONAL SPECIFICATION.
Electric Switches.
1. CHARLES EBENEZER CHALLIS of Number 30 Navarino Road, Hackney,
London N.E. Machinist, do hereby declare the nature of this invention to be as
follows:-
"
93
The object of my invention is to improve the construction of electric switches
so that the changes from "make to break and vice versa. are effected
instantaneously and completely, no intermedinte position being possible.
The means I employ may be described as a trigger, catch or locking piece which
holds the contact bar, or its equivalent, until sufficient energy is applied to the
handle and stored up by the driving spring to entirely overcome the friction of
contact and ensure a quick make
::
or break together with certain devices for
tripping the locking piece when enough force for the stroke is accumulated,
and the several modifications necessary to adapt the principle to various forms of
switches.
In one form of my switch I take a base of wood, state or other suitable material
and mount upon it a base plate and on opposite sides contact plates with terminals
for clamping cables, a spindle passing through the plate carries a contact bar or
equivalent which connects the contact plates when in the "on" position, the base
plate and contact bar have similar notches cut in them which are opposite in the
"on" or "off" position, in these notches gears a lucking piece which projects
somewhat above the contact bar a driving spring is wound upon the spindle the ends
pressing against the contact bar in opposite directions, over the spring is placed
a cam piece" which is connected to the handle on the upper end of the spindle,
this cam piece has studs, arins or wings upon it which bear against the ends of the
driving spring so that on the handle being turned the spring is wound up, one end
of the spring being lifted from the contact bar, the other end presses the bar in
one direction only, but the bar cannot rotate until a wing on the cam piece has
thrust the locking piece out of the notch when the bar immediately flies round to
its alternative position and again becomes locked.
"
In making another form of my switch I take a hollow cylinder or case of any
suitable material with a hole at each end through which passes a piston piece
carrying a sliding contact piece or collar upon it, the contact piece is held in the
on" and "off" positions by a locking piece actuated by certain grooves or
projections on the piston, the contact plates are placed at one end of the hollow
case, a spring or springs in or upon the piston engages with the contact piece in
such a way that on pressing either end of the piston the spring is compressed or
extended until enough force is stored to overcome the friction of contact and
ensure a quick "make or break" the locking piece is then tripped by the piston
and the change of position effected.
"
I add such terminals as are necessary for cable connections and any suitable cover
can be used.
C
1 1041

page_text: Electric Switches.
1, CHARLES EBENEZER CHALLIS, of 30 Navarino Road, Hackney, London N.E.
Machinist, 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:-
Referring to the accompanying drawings, a double break switch is shown in
Figures to 5, of which,
Fig. 1 is an elevation,
Fig. 2 is a section of same,
Fig. 3 is a plan with handle removed,
Fig. 4 is a plan with cam-piece removed,
Fig. 5 is a plan with contact bar removed.
Upon the base A Fig. 5 are fixed the contact plates F, F¹ R. R being the
connecting screws. The base plate G is shaped and slotted to receive the locking
spring which lies around it. The contact bar J Fig. 4 is slotted at S and S¹
to receive the loop or stud of spring which projects through. The spring M is
wound upon the spindle D the ends m, m' pressing against the arms of contact
bar and . The cam piece K Fig. 1 has two arms upon it which are bent
downwards at right angles and bear upon the central plate of the contact bar, one
edge of each of the arms touches the ends of the spring m, m³, from the opposite
edges of the arms, spring two wings which are curved somewhat towards the
centre, forming cams for disengaging the locking spring H.
It can now be seen that if the cam piece K is turned to the left (by means of
the handle) the arm will thrust the spring away from one end of the contact bar,
compressing the spring thereby, the bar is however prevented from turning by the
locking spring H, until the wing on K has thrust the loop of the spring H out of
the slot S, when the bar immediately flies round until the loop engages in the next
slot. In a like manner by turning the handle to the right, the contact bar is
returned to the position shown in Fig. 4.
In the sectional view Fig. 2 more details of construction are shown, namely: the
spindle is thickened to prevent a downward pressure upon the handle retarding the
movement of the contact bar, while it is secured in the base by the spring washer P
and the lock nuts Q. The screws, fix the cam piece to the handle C and at the
same time secure the leather washer L which renders the joint between the handle C
and the cover B dust tight.
Fig. 6 shows another form of locking spring T which may also take the form of
an ordinary spring pawl,
Fig. 9 shows a form in which the locking piece is attached to the contact bar,
and moves with it, instead of being fixed to the base plate as in Figs. 1 to 5.
A piston switch constructed according to my invention is shown in Figs. 7 and 8.
The case A has a central hole through it at each end, the interior being hollow:
through this is passed the piston C, with the spring E upon it. The push pieces D
are tubes or sleeves of sufficient diameter to allow room for the springs to work
between them and the piston, and they are attached at their outer ends to the
piston while their inner ends serve to trip or release the trigger piece G. Upon
the piston and between the springs the collar or contact piece F is placed. The
contact plates B B are shaped as segments of a cylinder. The locking lever or
trigger G with its spring II holds the contact plate in position "on or "off" by
locking on opposite sides of the collar K.
It will he seen that if the piston is thrust to the left one -pring is compressed,
this tends to withdraw the collar F from contact, but cannot do so until the inner
end of the sleeve or push picce D presses upon the wing on trigger picee G Fig. 8,
and releases it from the groove and allows the contact piece to fly off. The
"

page_text: collar F is now held on the opposite side of K; on the piston being thrust to the
right the spring is compressed until the push piece D reaches the wing G. when it
lifts the locking piece and the contact piece flies into contact as shown. In order
to reduce the length of the piston switches I may use a spring somewhat similar to
a clock spring upon the piston.
Figs. 10 and 11 show the plan and elevation respectively of another form of push
switch with locking piece the guides for same, on which terminals are fixed for
applied. A being the base, a contact plate, J the
contact bar,
attaching the leads, E E are the springs, P is a sliding piece with handle. G is the
locking piece. On the piece P being pushed forward one spring is compressed
until the locking piece is lifted out of the slot in the base, when the contact piece
flies into contact with F, the locking piece dropping into the next slot in a similar
manner to the piston switch. The locking and tripping pieces admit of many other
modifications than those shown, according to the type of switch to which they are
applied.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
The construction of switches with locking and trip pieces, substantially as
described, and for the purposes set forth.
Dated the 16th day of December 1891