Year: 1892

page_text: Date of Application, 7th Oct., 1892
Complete Specification Left, 7th July, 1893-Accepted, 9th Sept., 1893
PROVISIONAL SPECIFICATION.
Electric Switches.
1, CHARLES EBENEZER CHALLIS of No. 30 Navarino Road Hackney London
N.E. Machinist do hereby declare the nature of this invention to be as follows:-
The invention for electric switches consists of an improved mechanical device
and certain methods of construction for ensuring rapid transit of the contact bar
from the " on to the "off" position, and vice versa, however slowly the handle may
be turned; thus reducing the possibility of "arcing" through the switch being
left in imperfect contact.
"
The mechanism adapted to an ordinary circular base is as follows: A base plate
having a suitable race and stops for the contact bar, and means for connections, is
mounted centrally upon the base; a contact plate is mounted on the base and
overhangs the race on the contact plate; on the opposite side of the top of the base
is a small plate from which the fuse is connected to the base plate: so far the
A spindle is now fixed
fittings are practically identical with those commonly used.
centrally in the base plate by a screw and nut or otherwise; a triangular (or
polygonal) block is placed on the spindle; a contact bar having a lip turned over
one side of the block is then placed on the spindle; immediately above the contact
bar a groove is cut round the spindle; a slotted plate, with a lip turned down to
bear on one side of the block, is slid in the groove; a handle is mounted on the
spindle and attached to the plate by a screw or otherwise; preferably for this type
of switch the spring is made of wire which, having several convolutions upon a
stud fixed in the base, clasps the block between its crossed ends.
When the handle is turned the plate upon it turns the block, which increases the
angular distance between the legs of the spring until the block bears the spring
upon its angles instead of upon its sides. Till now the contact bar has not moved,
as it is held by the contact or the spring stop, but if the movement of the handle is
continued the block overtakes the lip on the bar and there is a direct push from the
handle through the block on to the contact bar, to overcome the frictional
resistance; the spring now being beyond the angles of the block the moment the
contact becomes weak the bar is driven round by the block acted upon by the
spring.
The above describes a fixed spindle, the spindle may however be turned by
means of a plate, a pin, or equivalent, on the handle acting on fints on the spindle;
the block is fixed to the spindle but the bar turns freely on it. The action is
almost exactly similar to that previously described.
A double break or bridging switch can be made by mounting suitable contacts
on the base and modifying the shape of the contact bar accordingly.
The invention also applies to main and other switches.
COMPLETE SPECIFICATION.
Electric Switches.
I, 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 :-
This invention for electric switches consists of an improved mechanical device,
capable of various methods of construction for ensuring rapid transit of the

page_text: contact bar from the “
handle may be moved.
"
on to the "off" position and vice versa, however slowly the
The several parts employed are: The handle or lever by which the motive
power is applied, this gears into a block or piece which may be greatly varied in
shape according to its position and duty, this in turn gears with the contact bar, a
spring controls the block.
The action is as follows: On the handle being turned it pushes on the block, and
this gradually compresses the spring, the maximum compression being obtained as
the block reaches midway between the two positions of rest; the block has not yet
moved the contact bar, but now gears with it, and on the movement of the handle
being continued the block is forced beyond the "dead point" and the spring
rapidly forces the block forward to its next position of rest, and the contact bar is
carried with it to its alternative position; the action being similar in either
direction; thus it is shown that there is sufficient play in the gearing between the
handle or lever and the block to prevent the rapid movement effected by the spring
being checked by the block overtaking the handle before it fully reaches the next
position, and also between the block and contact bar to admit of the block being
forced about half way to the next position (compressing the spring meanwhile)
before it operates the contact bar; should however for any reason the spring fail
to perform its duty the handle effects a positive drive through the block on the
contact bar.
The several parts above referred to are not necessarily of one substance but may
be built up should any advantage accrue therefrom.
In the accompanying drawings the principle above set forth is shown in a
circular switch in Figs. 1 and 2, and in a "tumbler" switch in Figs. 3, 4 and 5.
In each type the same letters indicate similar parts throughout. Figs. 1 and 2:are
the plan and elevation respectively of a circular switch A being the base of
suitable insulating material; to which is affixed by screws (or otherwise) the base
plate D; a retaining plate for holding the contact bar is shown at E.; and the
contact plate at F; the connection being made between the contact plate F and
the base plate D by means of the contact bar G; H, is the block, which in this
case is triangular with one side partly removed so as to leave an ear at each. side;
between these ears the contact bar rises; and from above a tongue projects: down-
wards between the two ears from the plate N; this plate is attached to the
handle C by screws; the flat spring K is held by the spindle M and after passing
downwards through the slot L in the base plate rises again through the slot. and
presses against one side of the block H; the spindle M passes through the spring
and base plate and is clamped beneath by a nut; the contact bar and block are
mounted on the spindle which is then reduced to form a shoulder, against which the
plate N works; being secured above by a nut; B is the cover of switch. The
fixing screws, holes and terminals are not lettered.
On the handle being turned the tongue on the plate N, bears against an ear on
the block H, and forcing, it round thrusts the spring. K backwards along the slot L
until the apex of the angle of block is in line with the spindle through. the centre of
the spring this without moving the contact bar-the other ear, on, blook now
presses against the side of the contact bar and if the movement of the handle is
continued, the block on passing the centre line will be forced round by the spring
and will carry the contact bar with it. There is sufficient space between the ears.
on block to allow for the transition to the next position without any further move-
ment of the handle so the rapid movement is not checked by it; and it can also be
seen that should the spring fail, the movement of the handle being continued the tongue
on M will drive the block by one ear, and the other ear on block will drive the
contact bar the entire distance.
The independent movement of the contact bar while the switch. is being operated
is. provided against by the friction of the contact and by the retaining piece E.
In Figs. 3, 4 and 5 are shown a "tumbler" switch, Fig. 3 being, the plan,, Fig. 4
the elevation, and Fig. 5 the end view of part of same, A is the base of insulating

page_text: material; B is the cover which may if desired, be of metal; D is the base plate
which being fixed to the base by screws, or otherwise rises in the form of a bridge
and carries a cap or collar in the centre of its arch; the collar may be screwed on
the outside for the attachment of cover, and is slotted through its crown for the
projection of the finger piece or lever C; this lever is pivotted on the transverse
pin M and upon this pin also turns the block H, and the contact piece G. The
lower portion of the lever C gears into a connection between the two plates of the
block H and the ears shown upon the block operate the contact bar; the contact
bar
preferably made of an insulating material with a metal core running through
it in the manner indicated to form a direct metallic connection between the contact
plates E and F; K is the spring which is carried in two slots L. L. cut through.
the wings depending from the collar, the spring bears against the apex of the
block H, and also against the flattened edge of the lever.
On the lever being thrust over it presses the block forward until the apex of the
block (or part most distant from the centre) is vertical with the pivot, the spring
then being at its utmost compression and the ears of block lying upon the contact
bar a slight further movement of the lever carries the block beyond the 'dead
point "and the spring completes the movement of the block, which carries the
contact bar with it.
66
The contact piece is always in contact with one of the contact plates (the
friction of which prevents independent movement of the contact bar while the lever
is being moved prior to the block passing the dead point) and completes the circuit
on making contact with the other contact plate.
Although in the example shown the whole of the moving parts are mounted on
one pivot this is not necessarily the case, in some types it being preferable for each
part to have a separate pivot. And further, wire springs may be substituted for
those shown, in each of the above cases.
I do not limit myself to the two styles of switches shown in the drawings, as the
principle is applicable to other types.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, declare that what I
claim is :
1. Electric switches in which the contact bar or its equivalent is controlled and
operated substantially in the manner set forth and shown.
2. In electric switches the use of a spring controlled block or its equivalent
between the handle or lever and the contact bar substantially in the manner and
for the purpose set forth and shown.
3. In electric switches the combinations of the various parts and modifications
thereof substantially as set forth and shown, for the purposes described.
Dukh of 1.1 1902
C. E. CHALLIS.