Improvements in Electrical Switches.
Year: 1893

page_text: Date of Application, 26th Sept., 1893
Complete Specification Left, 26th June, 1894-Accepted, 28th July, 1894
PROVISIONAL SPECIFICATION.
Improvements in Electrical Switches.
I JOHN HENRY TUCKER 40 Charles Road, Birmingham Engineer, do hereby
declare the nature of this invention to be as follows:-
My invention relates to improvements, more particularly in that class of
electrical circuit closing and opening devices (commonly known as electrical
switches) which are operated by means of a rocking handle. The motion of the
handle forcing the contact arm into such a position that the circuit is closed, and
at the same time compressing a spring, which is placed in such a position, that it
tends to force the contact arm to its "off" position. Upon movement of the
rocking handle motion is usually imparted to the contact arm, by means, either
of a link connecting them together, or, by the tail piece of the rocking handle
being shaped as a cam, and acting upon the face of the contact arm.
In carrying out my invention, I use a very short contact arm, and instead of
jointing it to the frame of the switch, I joint it to the tail piece of the rocking
handle, the contact arm to be of sufficient length to properly reach the contact
pieces, when the rocking handle is in the "on" position.
Upon the rocking handle being moved to its “off” position, the contact arm
rises and opens the circuit.
The rising or falling movement is imparted to the contact arm from the rocking
motion of the handle, by means of a connecting piece, one end of which is jointed
to the contact arın, at a convenient point, and its other end jointed to some fixed
portion of the switch.
The contact arm may be considered as a lever, having for its fulcrum, the end
of the connecting piece.
A spring for the purpose of giving a quick break, and keeping the contact arm
away from the contacts when the switch is "off," is placed preferably, between the
base of the switch, and the before mentioned connecting piece, and being in
compression tends to force up the connecting piece, and through it, the contact arm,
to which it is jointed.
The contact arm is held down against the action of the spring, when the joint
upon which the handle rocks, the joint which connects the tail piece of the handle
to the contact arm, and the joint connecting the contact arm to the connecting
piece, are brought into the line of thrust, thus locking the contact arm in
position.
A small movement of the rocking handle, towards its "off" position, will place
these joints sufficiently out of the straight line, to allow the spring to force up the
contact arm, and break the contact.
In case the contact arm should from any cause stick in the contacts, sufficiently
to prevent the spring from acting, the further movement of the rocking handle,
will force up the contact arm, & break the contact.
It is obvious that several modifications made be made; the connecting piece may
take the place of the before mentioned spring, by being formed as a spring, held
at one end, and jointed to the contact arm at the other end, or, it may be formed
as a sliding joint or bearing, in combination with a spring, or springs, for the before
mentioned purpose.
Dated this Twenty-fifth day of September 1893.

page_text: Improvements in Electrical Switches.
I, JOHN HENRY TUCKER, late of 40, Charles Road, in the City of Birmingham,
now of 10, Ryland Street, in the said City, Electrical Engineer, 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 :-
My invention relates to improvements in that class of electrical closing and
opening devices (commonly known as electrical switches) which are operated by
means of a rocking handle the motion of the handle forcing the contact arm into
such a position that the circuit is closed and at the same time compressing a spring
which is placed in such a position that it tends to force the contact arm to its "off"
position. Upon movement of the rocking handle motion is imparted to the contact
arm usually by means of either a link connecting the rocking handle and contact
arm together, or by the tail piece of the rocking handle being shaped as a cam and
acting upon the base of the contact arm.
According to this invention I construct and arrange the contact arm and spring
and connect the contact arm to the rocking handle in a peculiar manner as herein
described so as to ensure a quick break of the contacts when the rocking handle is
turned towards its "off" position and I also effectually prevent any sticking of the
contact lever to the contact pieces.
I will describe my invention by referring to the accompanying drawings in which
Figs. 1 and 2 are sectional elevations of an electrical switch constructed according
to this invention, Fig. 1 shewing the rocking handle and moving parts in the
positions which they occupy when the contact arm is in its "off" position and Fig. 2
shewing the same parts in the positions which they occupy when the contact arm
is in its "on" position;
Fig. 3 is a front elevation of the said switch with the outer covering removed,
and Fig. 4 is a back elevation of the same, and Fig. 5 is a plan of the same;
Fig. 6 shews separately the contact arm of the same in elevation and in plan;
Fig. 7 is a sectional elevation of a switch illustrating a modification of my
invention and Fig. 8 shews separately the spring portion of the switch shewn
by Fig. 7;
Figs. 9 and 10 are sectional side elevations of a further modification of my
invention, Fig. 9 shewing the rocking handle and moving parts in the positions
which they occupy when the contact arm is in its "off" position and Fig. 10
shewing the same parts in the positions which they occupy when the contact arm is
in its on position;
,,
Fig. 11 is a back elevation of the switch shewn by Figs. 9 and 10; Fig. 12 is a
sectional side elevation of a slightly modified form of the same; and Figs. 13 and
14 shew the two parts separately of the rocking handle of the switch shewn by
Fig. 12.
The same letters of reference indicate the same or corresponding parts in all the
figures of the drawings.
A is the rocking handle turning on the fulcrum pin a' fixed to the bracket B
secured to the base E of the switch; C¹ C' are the two fixed contacts of any usual
form and D is the contact arm made as usual of some material which is a non-
conductor of electricity and having at its outer end a copper or other contact
piece d adapted to fit in between the fixed contacts C¹ C' and complete the circuit
from one to the other.
In carrying out my invention I make the contact arm D very short, as will be
seen by an examination of my drawings, and, instead of jointing the contact arm to
the frame of the switch as is usual, I joint the contact arm D at f to the tail-
piece a of the rocking handle A, the said contact arm D being of sufficient length

page_text: to properly reach the fixed contact pieces C¹ C³ when the rocking handle A is in
the "on position see Figs. 2, 10 and 12. Upon the rocking handle A being
moved to its "off" position see Figs. 1, 7 and 9 the contact arm D rises and opens
the circuit. In the arrangement of my invention shewn by Figs. 1 to 6 this rising
movement is imparted to the contact arm D from the rocking motion of the
handle A by means of the connecting piece G one end of which is jointed to the
contact arm at g₁ somewhere about midway between the ends of the contact
piece D, and the other end of the connecting piece G is jointed at g³ to some fixed
part of the switch such as the joint pin which passes through ears 9 of the
connecting piece G and through holes in the sides of the bracket B. Thus
the contact arm D may be considered as a two armed lever having for its fulcrum
the pin g' in the end of the connecting piece G and having one of its arms jointed
at to the tail piece a of the rocking handle A and having its other arm & adapted
to engage between the fixed contacts C' C
For the purpose of giving a quick break and keeping the contact arm D away
from the contacts CC when the switch is "off" a spring is arranged to act upon
and force upwardly the fulcrum g¹ of the contact arm D. This spring which as
hereinafter described may be constructed and arranged in various ways is placed
by preference between the base E of the switch and the connecting piece Gas
shewn in Figs. 1, 2 and 3 the spring in this case being a small coiled spring I
which being in compression tends to force up the connecting piece G and through
it the contact arm D to which the connecting piece G is jointed as stated above.
The contact arm D is held down against the action of the spring I when the
joint a' (on which the handle A rocks) and the joint f (which connects the tail-
piece of the handle to the contact arm D) and the joint g' (connecting the
contact arm D to the connecting piece G) are brought into the line of thrust, thus
locking the contact arm in position as shewn by Fig. 2, the point ƒ passing slightly
beyond the straight line connecting the points a g₁ so as to make the rocking
handle A safe in this position.
A small movement of the rocking handle A towards its "off" position, that is
in the direction shewn by the arrow in Fig. 2, will place the point sufficiently ont
of the straight line joining the points a' gl as to allow the spring I to force up the
contact arm as shewn in Fig. 1 and break the contact.
In case the contact arm D should through any cause stick between the
contacts C'C' sufficiently to prevent the spring I from acting, a further movement
of the rocking handle A will force up the contact arin D to the position shewn by
Fig. 1 and break the contact.
It will be obvious that without departing from the nature of my invention the
moving spring fulcrum g¹ of the contact arm D may be constructed and arranged
in various other ways so as to move up and down as stated above when the rocking
handle A is moved to and fro to throw the switch on and off. For instance as
shewn by Fig. 7 the small spiral spring I is dispensed with and instead thereof the
connecting picce G is itself made in the form of a bent spring shewn separately by
Fig. 8 one end g'of which fits in a recess in the base E, and to ears g³ formed on the
other end the contact lever D is jointed. Figs. 9, 10 and 11 shew another
arrangement of my invention where the connecting piece G is all together
dispensed with and the fulcrum pin g' of the contact lever D is guided by and made
to slide up and down in slots b' 6' formed in the sides B of the bracket which is
fixed to the base E and also serves to carry the fulcrum pin of the rocking lever A.
It will be seen that the spring I fits in a recess in the base E and acts upon a
pusher piece through which the fulcrum pin g' is threaded as shewn more
clearly by Fig. 11. It will be seen that in this arrangement the spring I will have
the same action on the contact lever D as in the arrangement first above described
with reference to Figs. 1 to 6 both inclusive.
It is to be understood that if desired the tail piece a³ of the rocking lever A
may as in other electrical switches be made separate from the rocking lever A itself
as shewn in Figs. 12, 13 and 14 the part a having a flat portion as between which

page_text: "
and the top a of the jaw of the rocking lever A in which the tail piece a' fits
there is a slight clearance so that after the rocking lever A has been moved
through a short space in the direction of the arrow shewn in Fig. 12 the part a of
the jaw will come in contact with the flat part as of the tail piece a² and turn the
same far enough for the spring I to operate on the contact lever D and then as
the tail piece a² can turn through a short space independently of the rocking
lever A the contact lever D will be raised by the spring I out of circuit although
the rocking lever A has only been slowly moved through a short space.
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 :-
1. In an electrical switch and in combination with the rocking handle of the same
the employment of the contact arm D jointed at one end directly to the tail piece
of the rocking handle and adapted to turn upon a moving spring fulcrum situated
between the two ends of the said contact arm all substantially as and for the
purposes herein described with reference to the accompanying drawings.
2. In an electrical switch and in combination with the rocking handle of the
same, the contact arm D jointed at one end directly to the tail piece of the rocking
handle and adapted to turn upon a moving spring fulcrum forming the outer
moving end of a spring connecting piece such as G the other end of which is
stationary, all substantially as and for the purposes herein before described with
reference to Figs. 1 to 8 of the accompanying drawings.
3. In an electrical switch and in combination with the rocking handle of the
same, the contact arm D jointed at one end directly to the tail piece of the rocking.
handle and adapted to turn upon the moving spring fulcrum g¹ moving vertically
in fixed guides and acted upon by the spring I all substantially as hereinbefore
described with reference to Figs. 9. 10 11 and 12 of the accompanying
drawings.
4. In an electrical switch and in combination with the rocking handle of the
same, the employment of the contact arm D jointed at one end directly to the tail
piece of the rocking handle and adapted to turn upon a moving spring fulcrum
situated between the two ends of the said contact arm the said tail piece of the
rocking handle being made separate therefrom so as to have a slight movement
independently of the rocking handle all substantially as and for the purposes
herein before described with reference to Figs. 12, 13 and 14 of the accompanying
drawings.
Dated this 25th day of June 1894.
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.