Improvements in Switches for Regulating Currents of Electricity.
Year: 1891

page_text: Date of Application, 11th Dec., 1891
Complete Specification Left, 30th Aug., 1892-Accepted, 1st Oct., 1892
PROVISIONAL SPECIFICATION.
Improvements in Switches for Regulating Currents of Electricity.
We, JOHN CHARLES HOWELL, of New Dock, Llanelly, in the County of
Carmarthen, and PERCY EDWARD POWNALL, of 17 John Street, Llanelly
aforesaid, Electrical Engineers, do hereby declare the nature of this invention to
be as follows :-
This invention relates to that class of switch, with a main central moving contact
arm of conducting material, which makes electrical connection, with any one of any
number of fixed contacts of conducting material, which may be arranged round its
centre, one of the objects of our invention being to prevent sparking when moving
over the switch or rather to cause the sparking to take place at a point where no
harm will result.
According to one form of our invention the main contact arm may be moved by
means of a worm and worm wheel, or by means of a hand lever. The worm wheel
or the hand lever are electrically insulated from the main contact arm, by means of
any suitable insulating material; but they are fixed strongly to it by means of
screws, studs or bolts, between which and the contact arm the insulating material
is placed. By the side of the main contact arm a second contact arm is placed,
which with the main contact arm, makes electrical connection with any one of any
number of fixed contacts arranged round the centre of the main contact arm. The
second contact arm is fixed to the main contact arm by means of screws or studs,
so that they are together mechanically one, but they are electrically insulated from
one another by means of suitable insulating material interposed. The second
contact arm also makes electrical connection with a fixed contact piece on which it
slides. Suitable thimbles, screws or terminals are fixed to the contacts for
connecting the wires or electrical conductors.
When the main contact arm is moved by means of a worm and worm wheel, the
worm is fixed on a shaft on which are fixed one or two hand wheels by which
the shaft is turned. The worm and wormwheel are so arranged, that one turn of the
hand wheel will move the main contact arm from the centre of one to the centre of
the next of the fixed contacts. There is also a crank or an eccentric on the worm
shaft which by means of a connecting rod imparts a reciprocating motion to a
spindle which is guided by two guide brackets. This spindle imparts an oscillating
motion to a lever which is pivoted near its centre. At one end of this lever is fixed
a die through which the spindle passes. Fixed on the spindle are two collars, one
on each side of the die and between which and the die, springs are interposed to
relieve shocks. At the other end of the oscillating lever one or more contact
or sparking pieces are arranged, which make electrical connection, with an equal
number of fixed contact or sparking pieces. These sparking pieces may be made of
phosphor bronze, carbon, or any suitable material, and are held in position by wing
nuts or other means, so that they may be easily renewed. The lever makes one
oscillation for each revolution of the worm shaft.
Instead of the oscillating lever, the reciprocating spindle may have fixed at one
end a flat plate, or a damper of phosphor bronze, carbon, copper or other
material; which makes contact with one or a number of carbon plates, or carbon
in a finely divided state or powder, the whole being contained in a suitable pot or
case.
When a hand lever is used for moving the main contact arm, the reciprocating
spindle is moved by suitable gearing from the centre of the main contact arin and
so arranged that the spindle reciprocates once for each time the main contact arm

page_text: moves from the centre of one of the fixed contacts to the centre of the next. One
of the fixed sparking pieces is electrically joined to the fixed contact, on which the
second contact arm slides, and the other to the main contact arm, so that electrical
connection is made between the main contact arm and the second contact arm when
the oscillating lever makes connection at the sparking pieces. It is also arranged
80 that when the main contact arm leaves one of the fixed contacts, electrical
connection is made between it and the second contact arm, through the sparking
pieces and the lever. Also after the main contact arm has left, and before the
second contact arm has left one of the fixed contact pieces, the electrical circuit is
broken between the sparking pieces and the lever. The main contact arm also
bridges over the space between the fixed contact pieces; whilst the second contact
arm cannot make electrical connection with one of the fixed contacts until it has
left the contact that it was previously touching.
The break at the sparking pieces and the oscillating lever is also sufficiently
large to insure any arc or spark which may occur being broken previous to the
second contact arm leaving the fixed contacts. By this means all the sparking and
arcing is brought down to the two sparking pieces, which are easily renewed, and
so ensuring the efficient working of the switch when in constant use.
In addition to the arrangement described above which is for regulating the
strength of the current or electro motive force, by means of materials which resist
the passage of a current of electricity through them, being electrically connected
between any two of the fixed contact pieces, there may also be an arrangement
for reversing the direction of the electric current.
For this we may arrange two moving contact arms of electrically conducting
material each of which has two fixed contact pieces arranged round the centre on
which it moves. The two contact arms are linked together by means of a link of
insulating material, so that when one contact arm makes electrical connection with
the one of its two fixed contacts farthest away from a central point between the
two contact arms, the other contact arm makes electrical connection with the one of
its two fixed contacts nearest that central point and vice versa.
The two fixed
contacts nearest the central point between the two contact arms are electrically
connected together, as also are the two fixed contacts farthest away from that central
point. One of the pair of contacts is joined to the electro positive pole of the
conductors supplying the electric current and the other to the electro negative pole.
Thus the reversing of the direction of the current at the two moving contact arms
is made possible. The two contact arms may be moved by a hand lever, which is
fixed to the link of insulating material which connects the contact arms together.
To prevent the breaking of the electrical circuit at the two contact arms for reversing
the direction of the current previous to the circuit being broken at the main contact
arm for regulating the current, the locking arrangement described below may be
attached. This consists of a lever with two arms pivoted to one end on a fixed centre.
At the other end of one arm three notches are cut, which correspond to a projecting
piece, on the reversing hand lever, and when the locking lever is raised the
notches can fit over the projection and thus prevent the reversing hand lever
being moved.
The notches are so arranged that when the locking lever is raised it locks the
hand lever in that position where electrical connection is made at one or the other
of the reversing contact pieces or when the hand lever is in its central position and
no electrical connection is made. When the locking lever is dropped the reversing
hand lever is free to move. The other arm of the locking lever rests at its end on
a disc fixed to and concentric with the worm wheel or hand lever which turns the
main contact arm for regulating the current; in this disc is cut a notch which
corresponds to a projection on the arm of the locking lever. This projection drops
into the notch in the disc when the main contact arm and the second contact arm
attached to it have broken their electrical connection with the last of the fixed
contacts. Also previous to the second contact arm making electrical connection
again with the last of the fixed contacts, the projection on the locking lever is

page_text: lifted out of the notch in the disc by the disc turning round and thus locking the
hand lever in the manner described.
Sometimes for reversing the direction of the current of electricity the reversing
contact arms may be fixed on the centre carrying the regulating hand lever or
worm wheel, and in that case be moved directly by the hand lever or worm wheel
at the same time as the regulating contact arm. In this case the regulating contact
arm is placed on a different centre from the hand lever or worm wheel and will be
driven by toothed gearing in the following manner.
Fixed to the hand lever or worm wheel will be a segment on half of which gear
teeth will be formed internally and on the other half gear teeth will be formed
externally. On the regulating contact arm centre will be fixed a pinion or toothed
gear wheel with teeth formed all round, but one half of the teeth being placed with
their pitch line at a different radius from the centre than the other. Then when
the hand lever or worm wheel being in its central position, is moved in one direction,
the externally formed teeth will gear in with the teeth of small pitch line radius,
on the centre of the regulating contact arm and will cause that arm to move round
and make contact with the fixed contact pieces, and on the hand lever or worm
wheel being brought back to its original position the regulating contact arm also
returns.
Again if the hand lever or worm wheel is moved round in an opposite direction,
the internally formed teeth will gear in with the teeth of large pitch line diameter
on the centre of the regulating contact arm and cause it to move round in the same
direction, making contact with the fixed contact pieces as before. The object of
this being that in whichever direction the worm wheel or hand lever are moved
from the central position, the regulating contact arm will make electrical connection
with its fixed contact pieces and by the same movements the currents may be
reversed by the reversing contact arms making electrical connection with any
pair of their fixed contact pieces.
The whole switch described as above may be mounted on a base of slate or other
insulating material, and put into a suitable box, arranged so that the sparking
pieces are in an airtight box when used for colliery purposes.
Dated this 11th dox of December 1891
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, W.C., Agent for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Switches for Regulating Currents of Electricity.
We, JOHN CHARLES HOWELL of New Dock, Llanelly, in the County of
Carmarthen, and PERCY EDWARD POWNALL of 17 John Street, Llanelly afore-
said, Electrical Engineers, 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 that class of switch with a main central moving contact
arm of conducting material, which makes electrical connection with any one of any
number of fixed contacts of conducting material which may be arranged round its
centre, one of the objects of our invention being to prevent sparking when moving
over the switch, or rather to cause the sparking to take place at a point where no
harm will result. According to one form of our invention the main contact arm A,
Figs. 1 and 2, may be moved by means of a worm and worm wheel B and C,
Fig. 1, or by means of a hand fever D, Fig. 2. The worm wheel or the hand
lever is electrically insulated from the main contact arm by means of any suitable
insulating material, but they are fixed strongly to it by means of screws, studs or
bolts, between which and the contact arm the insulating material is placed.
By the side of the main contact arm a second contact arm A, Figs. 1 and 2, is
placed, which with the main contact arm, makes electrical connection with any one

page_text: of any number of fixed contacts E', E², E' Figs. 1 and 2, arranged round the centre
of the main contact arm. The second contact arm is fixed to the main contact
arm by means of screws or studs, so that they are together mechanically one, but
they are electrically insulated from one another by means of suitable insulating
material interposed. The second contact arm also makes electrical connection with
a fixed contact piece F, Figs. 1 and 2, on which it slides. Suitable thimbles,
screws or terminals are fixed to the contacts for connecting the wires or electrical
conductors.
When the main contact arm is moved by means of a worm and worm wheel, the
worm is fixed on a shaft on which are fixed one or two hand wheels L', L³, Fig. 1,
by which the shaft is turned. The worm and worm wheel are so arranged that
one turn of the hand wheel will move the main contact arm from the centre of one
to the centre of the next of the fixed contacts. There is also a crank or its
equivalent G, Figs. 1 and 2, or an eccentric on the worm shaft which by means of
a connecting rod H, Figs. 1 and 2, imparts a reciprocating motion to a spindle I,
Figs. 1 and 2, which is guided by guide brackets.
This spindle imparts an oscillating motion to a lever K, Fig. 1, which is pivoted
near its centre.
At one end of this lever is fixed a die Y, Fig. 1, through which the spindle
passes. Fixed on the spindle are two collars, one on each side of the die and
between which and the die, springs are interposed to relieve shocks.
At the other end of the oscillating lever one or more contact or sparking
pieces M1, M2, Fig. 1, are arranged which make electrical connection with an equal
number of fixed contact or sparking pieces N', N2, Fig. 1. These sparking pieces
may be made of phosphor bronze, carbon, or any suitable material, and are held in
position by wing, nuts, or other means, so that they may be easily renewed. The
lever makes one oscillation for each revolution of the worm shaft.
Instead of the oscillating lever, the reciprocating spindle may have fixed at one
end a plate X, Fig. 2, or a damper of phosphor bronze, carbon, copper or other
material which makes contact with one or a number of carbon plates, or carbon in a
finely divided state or powder, the whole being contained in a suitable pot or
case Y, Fig. 2.
When a band lever is used for moving the main contact arm A, the reciprocating
spindle is moved by suitable gearing from the centre of the main contact arm and
so arranged that the spindle reciprocates once for each time the main contact arm
moves from the centre of one of the fixed contacts E¹ &c. to the centre of the next.
One of the fixed sparking pieces N' N' is electrically joined to the fixed contact F,
on which the second contact arm A' slides, and the other to the main contact
arm A, so that electrical connection is made between the main contact arm and the
second contact arm when the oscillating lever makes connection at the sparking
pieces. It is also arranged so that when the main contact arm leaves one of the
fixed contacts, electrical connection is made between it and the second contact arm,
through the sparking pieces and the lever.
Also after the main contact arm has left, and before the second contact arm
has left one of the fixed contact pieces, the electrical circuit is broken between
the sparking pieces and the lever. The main contact arm A also bridges over
the space between the fixed contact pieces, whilst the second contact arm cannot
make electrical connection with one of the fixed contacts until it has left the
contact that it was previously touching. The break at the sparking pieces and
the oscillating lever is also sufficiently large to insure auy are or spark which
may occur being broken previous to the second contact arm A¹ leaving the fixed
contacts. By this means all the sparking and arcing is brought down to the two
sparking pieces, which are easily renewed, and so ensuring the efficient working of
the switch when in constant use.
In addition to the arrangement described above which is for regulating the
strength of the current or electro motive force, by means of materials which resist
the passage of a current of electricity through them, being electrically connected

page_text: between any two of the fixed contact pieces, there may also be an arrangement for
reversing the direction of the electric current. For this we may arrange two
moving contact arms of electrically conducting material O'O' Figs. 1 and 2, each
of which has two fixed contact pieces P¹ P and Q Q, Figs. 1 and 2, arranged
round the centre on which it moves. The two contact arms are linked together by
means of a link of insulating material, so that when one contact arm makes electrical
connection with the one of its two fixed contacts farthest away from a central point
between the two contact arms, the other contact arm makes electrical connection
with the one of its two fixed contacts nearest that central point and vice versa. The
two fixed contacts nearest the central point between the two contact arms are
electrically connected together, as also are the two fixed contacts farthest away
from that central point. One of the pair of contacts is joined to the electro
positive pole of the conductors supplying the electric current and the other to the
electro negative pole. Thus the reversing of the direction of the current at the
two moving contact arms is made possible.
The two contact armis may be moved by a hand lever R Fig. 1, which is fixed to
the link of insulating material which connects the contact arms together. To
prevent the breaking of the electrical circuit at the two contact arms for reversing
the direction of the current previous to the circuit being broken at the main
contact arm for regulating the current, the locking arrangement described below
may be attached.
At
A lever S T, Fig. 1, with two arms is pivoted at one end on a fixed centre.
the other end of one arm S, Fig. 1, three notches w are cut which correspond to a
projecting piece w¹ on the reversing hand lever, and when the locking lever is raised
the notches can fit over the projection w' and thus prevent the reversing hand
lever being moved. The notches are so arranged that when the locking lever is
raised it locks the hand lever in that position where electrical connection is made
at one or the other of the reversing contact pieces or when the hand lever is in its
central position and no electrical connection is made. When the locking lever is
dropped the reversing hand lever is free to move. The other arm T, Fig. 1, of
the locking lever rests at its end on a disc fixed to and concentric with the worm
wheel or hand lever which turns the main contact arm for regulating the current;
in this disc is cut a notch, Fig. 1, which corresponds to a projection U on the arm
of the locking lever. This projection drops into the notch in the disc when the
main contact arm and the second contact arm attached to it have broken their
electrical connection with the last of the fixed contacts. Also previous to the
second contact arm making electrical connection again with the last of the fixed
contacts, the projection U on the locking lever is lifted out of the notch in the
disc by the disc turning round and thus locking the hand lever in the manner
described.
Sometimes for reversing the direction of the current of electricity the reversing
contact arms may be fixed on the centre carrying the regulating hand lever or
worm wheel, Fig. 2, and in that case be moved directly by the hand lever or worm
wheel at the same time as, the regulating contact arm.
In this case the regulating contact arm is placed on a different centre from the
hand lever or worm wheel and will be driven by toothed gearing in the following
manner.
Fixed to the hand lever or worm wheel are segments V1, V2, Fig. 2, on half of
which gear teeth are formed internally V, Fig. 2, and on the other half gear teeth
are formed externally V₁, Fig. 2. On the regulating contact arm centre will be
fixed a pinion or toothed gear wheel w³, w, Fig. 2, with teeth formed all round,
but one half of the teeth being placed with their pitch line at a different radius
from the centre than the other. Then when the hand lever or worm wheel being in
its central position, is moved on one direction, the externally formed teeth V¹, Fig. 2,
will gear in with the teeth of small pitch line radius w³, Fig. 2, on the centre of
the regulating contact arm and will cause that arm to move round and make con-
tact with the fixed contact pieces, and on the hand lever or worm wheel being

page_text: brought back to its original position the regulating contact arm also returns.
Again if the hand lever or worm wheel is moved round in an opposite direction,
the internally formed teeth V2, Fig. 2, will gear in with the teeth of large pitch
line diameter w³, Fig. 2, on the centre of the regulating contact arm and
cause it to move round in the same direction, making contact with the fixed contact
pieces as before.
The object of this is that in which ever direction the worm wheel or hand lever
are moved from the central position, the regulating contact arm will make electrical
connection with its fixed contact pieces and by the same movements the current
may be reversed by the reversing contact arms making electrical connection with
any pair of their fixed contact pieces.
The whole switch described as above may be mounted on a base of slate or other
insulating material, and put into a suitable box, arranged so that the sparking pieces
are in an airtight box when used for colliery purposes.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
:-
1. Improvements in electric switches consisting in bringing the sparks which
would otherwise occur on the working faces of the contacts, to positions where they
will be harmless, substantially as described.
2. In electric switches the improved means for controlling the "sparking,"
substantially as described and illustrated in Figs. 1 and 2.
3. In electric switches the improved means for reversing the direction of the
current, substantially as described and illustrated in Figs. 1 and 2.
4. The improvements in switches for regulating currents of electricity,
substantially as described and illustrated in Figs. 1 and 2.
Dated this 30th day of August 1892.
PHILIP M. JUSTICE, Fel. Chart. Inst. P.A.,
55 & 56, Chancery Lane, London, Agent for the Applicants.