Improvements in Locked Switches for Electric-current Circuits.
Year: 1890

page_text: Date of Application, 1st Oct., 1890
Complete Specification Left, 29th Nov., 1890-Accepted, 10th Jan., 1891
· PROVISIONAL SPECIFICATION.
Improvements in Locked Switches for Electric-current Circuits.
We, JOHN ABBOTT ILIFFE, Gentleman, and FRANCIS TEAGUE, Electrical Engineer,
both of the Acme Electric Works, Ferdinand Street, Chalk Farm, in the County of
London, do hereby declare the nature of this invention to be as follows:-
:-
This invention relates to certain improvements in that class of switches used, for
controlling electric current circuits known as lock switches, and it constitutes improve-
ments upon the invention covered by Letters Patent No. 6267, dated 29 April 1887,
and No. 18,825, dated 24 December 1888. The object of the present invention is
to avoid or remove certain difficulties found in the practical working of the above
specified invention, and to make the same more complete and efficient.
In the Specifications to the above named Letters Patents, devices were described to
ensure a safely locked connection, combined with a quick break of contact when
disengaged; the latter thereby lessening the heat action of the current upon the
separating contact parts.
The devices comprised a spindle with an outer arm and actuating handle, a switch
arm turning freely on the spindle and caused to slide upon the terminal contact plates
by the outer arm and actuating handle, an inner arm, also freely turning upon the
spindle but secured to the switch arm, and a broad flat spring, at right angles to the
spindle and acting vertically against the bottom portions of the inner and outer arms.
A spiral spring, coiled around the base of the handle spindle, was caused to act thereon
in the direction of contact breaking. In making contact, the partial rotation of the
handle caused the outer arm to carry with it the switch arm until it was fully seated
upon the terminal contact plates, and winding up the spiral spring. The inner arm,
also partaking of the movement of the attached switch arm, depressed the flat spring
by sliding over it until the switch arm was fully seated, when the end of the flat spring
came against a detent formed on the bottom of the inner arm, which firmly locked the
latter, and its attached switch arm in the contact position; thus securely establishing
the circuit connection. By reversing the operation, the handle with its attached outer
arm has a certain amount of free movement until the sloping bottom of the outer arm
rides over and depresses the flat spring from its locking position, when the-spiral
spring immediately acts upon the spindle and outer arm and causes the switch arin to
fly off, thus rapidly breaking the contacts.
It was found in practice that sometimes, when the friction hetween the switch arın
and terminal contact plates was very great, that the switch arm would not fly back
when released, and that force had to be applied for the purpose. This was not only
a cause of danger and delay, but frequently led to the breaking of the handle, when
the switch practically becomes useless.
By our present invention we make the outer arm wider, and carry the stop thereon
farther back from that part of the front of the outer arm which first rides over th, flat
spring. By this means we not only depress the flat spring for a longer relative time
in turning the handle, but the face of the outer arm itself comes in contact with the
switch arm in the direction of release, (which was not the case formerly), and causing
the same to slide upon the terminal contact plates until near the edge, the spiral spring
acts with an accelerating force, and rapidly breaks the contacts.
་
We also make a stronger and simpler handle by casting or forming a T upon the
top of the spindle, and which is integral therewith. We let this into a thick piece of
vulcanite, grooving the latter to receive the T head, and secure both together by two
small screws or rivets.
We also place a spiral spring on the top of the handle, in some forms of switches,
to press the switch arms down, and find this much more convenient than beneath the

page_text: base, as formerly. When two or more compound switches are used, the handle is
placed between the switch arm spindles, and is connected thereto, by connecting rods
of insulating material, working on crank pins secured to corresponding cranks on the
switch arms, and handle spindle. In this latter case, the spiral spring for making
good pressure contact is placed over the switch arms, and not on the handle spindle.
Each terminal contact plates has a socket or sleeve which is let into the slate, or
other insulating material forming the switch base. This socket is slightly tapering to
receive a correspondingly turned terminal post. The latter is drilled up a portion of
its length from the bottom, and the wire conductor is soldered therein and two of the
terminals are then placed in the position they are to occupy. The base, with the
tapering sockets, are slipped over and with a nut screwed down upon each contact
plate, good contact is secured.
In the case of high tension currents, a ring and washer, or flanged annular ring of
vulcanized fibre, vulcanite, porcelain or other suitable insulating material, is interposed
between the terminal contact plates and the switch arms, the latter being curved over
the top of the flanged ring to clear the same. The base or bearing of the handle
spindle is also guarded by the flanged ring, which thus serves to prevent short
circuiting from one side, across the centre, to the other side.
We combine a vulcanite or vulcanized fibre stop, with our improved handle and
arm, which is secured to the switch base so as to bear against one of the terminal
contact plates. This is so arranged that when contact is broken, in the manner already
described, the force of the spiral spring causes the switch arm to fly off against the
stop, and this is made of such a width as to arrest the switch arm in the centre of the
space between the terminal contact plates.
It is to be understood that we may combine a number of our improved switches
together upon one base, and work them simultaneously (if required) by suitable con-
necting rods, pins, and crank arms. Also, that we may arrange the flat locking spring
parallel with the handle spindle, and adapt the outer and inner arms to engage there-
with, instead of placing it at right angles thereto, as above described.
Dated this 30th day of September 1890
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Locked Switches for Electric-current Circuits.
We, JOHN ABBOTT ILIFFE, Gentleman, and FRANCIS TEAGUE, Electrical Engineer,
both of the Acme Electric Works, Ferdinand Street, Chalk Farm, in the County of
London, 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 relates to certain improvements in that class of electric switches
known as lock switches, and it constitutes improvements upon the invention covered
by Letters Patent No. 6267 dated 29th April 1887, and No. 18,825 dated
24th December 1888. The object of the present invention is to avoid or remove
certain difficulties found in the practical working of the above specified inventions,
and to make the same more complete and efficient.
In the Specifications to the above named Letters Patents devices were described to
ensure a safely locked connection, combined with a quick break of contact when
disengaged; the latter thereby lessening the heat action of the current upon the
separating contact parts.
The devices comprised a spindle with an outer arm and actuating handle, a switch
arm turning freely on the spindle and caused to slide upon the terminal contact plates
by the outer arm and actuating handle, an inner arm, also freely turning upon the spindle
but secured to the switch arm, and a broad flat spring, at right angles to the spindle,
and acting vertically against the bottom portions of the inner and outer arms.
A

page_text: spiral spring, coiled around the base of the handle spindie, was caused to act thereon
in the direction of contact breaking. In making contact, the partial rotation of the
handle caused the outer arm to carry with it the switch arm until it was fully seated
upon the terminal contact plates, and winding up the spiral spring. The inner arm,
also partaking of the movement of the attached switch arm, depressed the flat spring
by sliding over it until the switch arm was fully seated, when the end of the flat
spring came against a detent formed on the bottom of the inner arm, which firmly
locked the latter, and its attached switch arm in the contact position; thus securely
establishing the circuit connection. By reversing the operation, the handle with its
attached outer arm has a certain amount of free movement until the sloping bottom
of the outer arm rides over and depresses the flat spring from its locking position,
when the spiral spring immediately acts upon the spindle and outer arm and causes
the switch arm to fly off, thus rapidly breaking the contacts.
It was found in practice that sometimes, when the friction between the switch arni
or brush, and terminal contact plates was very great, that the switch arm would not
fly back when released, and that force had to be applied for the purpose. This was
not only a cause of danger and delay, but frequently led to the breaking of the
handle, when the switch practically became useless.
.
This invention is illustrated by the accompanying drawings, of which
Fig. 1 is a vertical section and Fig. 2 a plan of a single switch; the section being
taken upon the line c―d.
Fig. 3 is a perspective view of the improved handle and outer or releasing arm;
Fig. 4 is an elevation of the said outer or releasing arm but varied at the top or
handle. portion in accordance with the section thereof in Fig. 6;
Fig. 5 is a detail view of the inner or locking arm in its relative position to the
locking or broad flat spring;
Fig. 6 is a vertical section (on the line a-b) and Fig. 7 a plan of the same kind
of switch as that shown in Figs. 1 and 2 but with the vertical pressure spring placed
in the modified handle instead of beneath, as in Fig. 1.
Fig. 8 is an elevation and Fig. 9 a plan of a double switch having the vertical
pressure spring placed above each brush.
The outer or releasing arme is made wider, and the stop e¹ is carried further back
from the curved front, which first rides over the flat or locking spring f, than formerly.
By this means the locking spring f is not only depressed for a relatively longer time in
turning the handle, but the face of the releasing arm e engages with the switch arm g,
or brush g' in the direction of release, (which was not the case formerly), and causing
the brush g' to slide upon the terminal contact plates until near the edge, when the
spiral spring (shown in Figs. 5, 6, 8 and 9, but omitted in Fig. 1 for clearness),
acting upon the brush, arms, and handle with an accelerating force, rapidly breaks
the contacts.
The releasing arm e, cap e² spindle e³, Ţ handle e³, are either cast in one solid piece
as shown in Fig. 3, or the spindle is brazed to the other portions as shown in Fig. 1.
The handle e is let into a grooved block of vulcanite e and riveted together.
In the single switch, Figs. 6 and 7, and in the double switch Figs. 8 and 9, are
shown upon the upper part of the spindles a spiral spring i which presses the brush g
vertically upon the terminal contact plates j,j. In Fig. 1, this vertical pressure
spring i is placed on the lower part of the spindle, but the former arrangement is
more convenient for adjusting the pressure by means of the nuts ¹ upon the screwed
spindle e³. In Fig. 6, the spring is let into a recess in the ball top of the releasing
arme (shown also in Fig. 4), to which the handle e is secured. When two or more
switches are compounded, the handle is more conveniently placed between the switch
arm or brush spindles, and connected to the switch arms g, g, by connecting rods k, k
of insulating material working on crank pins k¹, k¹, secured at cue end to the switch
arms 9, 9, and at the other to one or more corresponding crank arms or discs g³
secured to the handle spindle e³, as shown in Figs. 8 and 9.
Fig. 5 represents the inner or locking arm m in the locked position against the

page_text: locking spring f, when the circuit is connected; as shown in the plans Figs. 2 and 7.
In this case, the detent m¹ of the locking arm m has been caused to ride over the
locking spring until it passed the detent, when the spring f, assuming the position
shown, locked the arm m, and brush g¹ (which are connected together), the releasing
arme also passing over the spring fat the same time (as indicated by the dotted
lines) being actuated by the handle e. When the handle is turned back to break
the circuit connection, the arm e is caused to travel with it, and the rounded front
edge thereof rides over the spring fand depresses it clear of the detent m', when the
coiled turning spring h, being free to act upon the arm m, turns it together with the
brush g', arm e and handle e, and the circuit is rapidly broken; the stop e¹ coming,
in contact with the end of the spring f, serves to arrest the handle at right angles to
its position when the circuit is connected.
Each terminal contact platej has a socket or sleeve j¹, shown by dotted lines in
Fig. 8, which is let into the slate or other insulating base b. This socket slightly
tapers to receive a correspondingly turned terminal post . The latter is drilled up
a portion of its length from the bottom to receive the wire conductor which is soldered
therein; and two of the terminals are placed in the position they are to occupy. The.
base, with the tapering sockets, are slipped over, and with a nut screwed down firmly
upon each contact plate j, j, good contact is secured.
In Fig. 2 a stop n of vulcanized fibre, or other suitable material is shown and
adapted to arrest the motion of the brush g when the circuit connections are made,
and for this purpose the stop n is secured to the base 1 by a screw from the bottom
(shown in Fig. 1), which is afterwards cemented over. The stop is placed solidly
against one edge of a contact plate along a radial line from the centre of the
switch. The other end of the stop is also cut to a similar radial line, and this
arrangement has been hitherto used; but it was open to the objection that it indented
the edge of the brush from the latter striking the stop at the inner angle, especially
upon the side which received the sudden blow when the circuit is broken. Our
improved arrangement to avoid this is shown in Fig. 7, in which the lines followed
by the edges of the contact plates j, j and fibre stop n are not along the radial
lines, as before, but parallel thereto at a distance of one half of the width of the
brush, so that the latter is arrested by the whole width of the stop in both positions-
either on or off the relative place of the brush being exactly at right angles, in the
two positions, (which was not the case formerly), and this latter advantage of placing
the brush exactly midway between the contacts, is obtained by the length of the arc or
segment of the stop n.
In the case of high tension currents, a ring and washer, or flanged annular ring
of vulcanized fibre, vulcanite, porcelain, or other suitable insulating material (not
shown), is interposed between the terminal contact plates j, j, and the switch arms or
brushes g and g, the latter being curved over the top of the flanged ring to clear the
same. The base or bearing o of the handle spindle is also guarded by the flanged ring,
which thus serves to prevent short circuiting from one side, across the centre, to the
other side.
It is to be understood that we may combine a number of our improved switches
together upon one base, and work them simultaneously (if required) by suitable connect-
ing rods, pins, and crank arms. Also that we may arrange the locking spring parallel
with the handle spindle, and correspondingly adapt the outer or releasing arm, and
the inner or locking arm to engage therewith, instead of, placing it at right angles
thereto as shown and described.
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 ;-
1. The improvements in locked switches for electric current switches, substantially
as and for the purpose herein described and illustrated.
2. In a locked electric switch, the combination of the improved releasing arm e,

page_text: extended stop e¹, locking arm m, locking spring f, coiled spring h, spindle e³,
actuating handle e, brush g' and contact terminal plates j, j, substantially as and
for the purpose described.
3. In a locked electric switch, the combination of the arm e with extended stop e¹,
cap e³, spindle e³, and handle e all integrally formed or connected, substantially as
described.
4. In a locked electric switch, the combination of a spindle e³, a spring i on the
upper part of said spindle adapted to exert vertical pressure upon a brush g¹ against
the faces of two terminal contact plates j, j, and an actuating handle or rod for turning
said brush, substantially as and for the purpose described.
5. In a locked electric switch, the combination of a spindle e³ baving a solid
T headed handle integrally formed therewith, and a grooved insulating finger-piece
enclosing said handle and rigidly attached thereto, substantially as described.
6. In a locked electric switch, the combination of a spindle e³, a base or support o
therefor, a contact brush g' threaded upon the said spindle, a disc e² or plate g
upon the top of the said brush, a spring i and adjusting nuts, adapted to press
vertically upon the said brush and a means of turning the same, substantially as and
for the purpose described.
7. In a locked electric switch, the combination of an insulated base with a terminal
contact plats j, formed with a conically bored socket j¹ let into the said baso, a corre-
spondingly formed terminal post fitting into the said socket and secured therein by an
outer nut 12, the said terminal post being bored from the bottom to receive a conductor,
substantially as and for the purpose described.
Dated this 29th day of November 1890.
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicants.