Improvements in Electrical Cut-out Apparatus.
Year: 1898

page_text: Date of Application, 11th Feb.,
Complete Snacification Loft 11th No
1893
1908 Accented
20th lon 1900
PROVISIONAL SPECIFICATION.
Improvements in Electrical Cut-out Apparatus.
I, LEONARD ANDREWS, of 20, South Terrace, Hastings, in the County of
Sussex, Electrical Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention has reference to improved constructions of cut-out apparatus
for controlling electric circuits and it has for object to render such apparatus
more sensitive, reliable and effective than such apparatus as heretofore con-
structed.
In one construction of cut out apparatus according to this invention and
designed for use as a return current cut out, a movable contact piece adapted to
make and break connection in a main or outgoing lead is adapted to be moved
into the open position by a weight or equivalent that is normally held in a
raised position by a trip or releasing device controlled by an electro-magnetic
device comprising a series coil adapted to be arranged in the main or outgoing
lead and a shunt coil adapted to be connected across the main and return leads,
these coils, preferably provided with magnetic cores or their equivalent, being
so inductively arranged in relation to one another as to constitute in effect a
shunt motor wherein one of the coils with its core, if it has one, serving as
an armature, is mounted to turn and will tend to turn in one direction against
a stop or resistance for a forward current and lock the movable contact piece
in its closed position and to turn in the opposite direction for a return current
and release the weight; which in falling will move the contact piece into the
open position and so open the main or outgoing lead. The trip or releasing
device comprises according to one arrangement a lever that is connected at its
pivoted end to a catch that normally holds the weight in the raised position
and is provided at its opposite end with a short bent part or catch that normally
bears against a pin carried by a disc or arm connected to the movable coil and
core so as to turn therewith about the same centre. The point of contact
between the pin and bent end of the lever is so arranged that it is located in an
arc that passes through the centre of motion of the coil and core, or armature,
and has its centre at the axis about which the lever turns, and the said bent end of
the lever is so shaped that the pin can move over it in a direction to release it without
having to move the lever and connected parts. By this construction the trip device
is rendered very sensitive and reliable, as the only resistance which the coil
and core when moved backward by a return current have to overcome, is that
due to friction between the pin and lever which is small and may be rendered
still less by placing an anti-friction roller on the pin. Consequently a small
return current will suffice to effect the automatic opening of the switch or cut out.
As will be obvious cut out apparatus of the kind described can be constructed
in various forms..
In one arrangement the movable contact, consisting of a channelled piece
of conducting material, for example bronze, is carried by a porcelain or liko

page_text: insulator having a corrugated exterior and clamped between a pair of connected
movable bars that are pivoted at the opposite end to a bracket extending from
an iron base plate designed to be held in a vertical position against a wall or
like support. The ends of the movable contact piece are arranged to be each forced
between a pair of split metal spring contacts carried by a porcelain or like
insulator having a corrugated exterior and a hollow base that is fixed in a
raised or channelled part of the base plate by lead, sulphur or like cementing
material, the arrangement being such that when the fixed and movable contacts
are properly engaged, the pivoted bar is vertical or approximately 80.
At the
outer side of the movable contact is a weight carried by the curved arm of a
lever pivoted upon the same pin as the bar carrying the movable contact and
the other arm of which is made short and so arranged that when the weight
has been released and has acquired by falling some momentum it will strike
against an abutment on the contact carrying bar and rapidly disengage the
movable contact from the fixed contacts. The weight has secured to its upper
part a spring catch adapted to engage with a tooth or shoulder on a collar or
disc fixed to a horizontal spindle that is mounted in brackets extending from
the upper part of the base plate and has fixed to it the upper end of a trip
lever.
At the lower part of the iron base is another raised or channel part to which
is secured, by lead sulphur or like material, a corrugated porcelain insulator
carrying a binding screw or equivalent for connection to a return main. Centrally
between the two raised channelled parts, the base is provided with a projecting
part having a curved surface and designed to serve as a pole piece. In the
space between this pole piece and the raised or channelled parts is arranged a
series coil which may advantageously consist of a few turns of copper tape
insulated from each other and designed to carry the greatest current the
apparatus will be called upon to carry. The inner end of this coil is fixed to a
metal plate carried by a metal rod extending from a boss which is provided
with a metal socket piece in which one end of the main or outgoing lead can be
electrically secured, and which is carried by another insulator secured to the
lower raised or channel part of the base plate. The plate, rod, boss and socket
piece may consist of a bronze or other metal casting. The other end of the series
coil is secured to a metal supporting piece connected to a plate carrying one of
the pairs of fixed contacts. The plate carrying the other pair of fixed contacts
is formed with a socket piece in which is to be fixed one end of the adjoining
length of main or out-going lead. The shunt winding of fine wire is wound
upon an ordinary shuttle shaped iron core mounted on knife-edges or other
bearings in lugs projecting from the base plate and located within the series.
winding, one end of the shunt winding being connected to the series winding 4
and the other to the insulated terminal at the lower part of the base plate. Over
the series and shunt windings is or may be fixed an iron plate having a pole
piece opposite to that on the base plate so that when the series current is traversed
by an electric current it will form with the base plate a double magnetic circuit
which is completed through the core of the shunt winding which is arranged 4
between the polar projections. This latter core and winding are normally so
held that the diametrical line jointing the poles of the core are at right angles
or nearly so to the diametrical line joining the polar projections magnetised by
the series winding. The core may be held in this position against a stop by a
weight, or spring, (hereinafter called a weight), preferably by making one polar 5
side or end of the armature core heavier than the other. To one of the plates
at the end of the armature core is fixed a pin that engages the lower bent end of
the trip lever, the pin and lever end being arranged as hereinbefore described,
and so as normally to hold the trip lever in a position to hold up the pivoted weight.
The arrangement is such that current flowing in a forward direction through 5
the series winding will assist the armature weight, to hold the shunt core and
coil in the position mentioned, but a return current in the said winding will

page_text: overcome the weight and turn the shunt core and winding in the opposite direction
sufficiently to disengage the trip pin from the trip lever and release the pivoted
weight for opening the cut out.
By removing the shunt coil from the armature core and providing a weight
or spring that normally acts to hold the core against a stop in opposition to
the rotative action of a current in the series coil of normal amount and in such
a position that the diametrical line joining the pole pieces of the core will form
an angle of about 45° with the diametrical line joining the polar projections
magnetised by the series winding but which will yield and allow the care to
rotate to a small extent when the series coil is traversed by a predetermined
greater current, the apparatus herein before described can be used as an excess
current cutout, the trip-lever and pin being of course so arranged that the
lever will be released by rotation of the core against the opposing action of the
spring or weight.
The apparatus hereinbefore described is specially suitable for use as a low.
tension cut out.
In speaking of the direction of current I do not intend to exclude alternato
currents but have described the invention for simplicity with direct current
examples. I apply my invention in the case of alternate current working by
making the apparatus according to the principles well understood, by which,
although the currents are alternating, the simultaneous directions of the currents
act relatively as described with reference to direct currents. When used for
alternating currents the cores should preferably be laminated to prevent eddy
currents.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.
Improvements in Electrical Cut-out Apparatus.
I, LEONARD ANDREWS, of 20, South Terrace, Hastings, in the County of
Sussex, 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;―
This invention has reference to improvements in cut-out apparatus for con-
trolling electric circuits and it has for object to render such apparatus more
sensitive, reliable and effective than such apparatus as heretofore constructed.
In one construction of cut out apparatus according to this invention and
designed for use as a return current cut out, a movable contact piece adapted to
make and break connection in a main or outgoing lead is adapted to be moved
into the open position by a weight or equivalent that is normally held in a
raised position by a trip or releasing device controlled by an electro-magnetic
device comprising a series coil adapted to be arranged in the main or outgoing
lead and a shunt coil adapted to be connected across the main and return leads,
these coils, preferably provided with magnetic cores or their equivalent, being
so inductively arranged in relation to one another as to constitute in effect a
shunt motor wherein one of the coils with its core, if it has one, serving as
an armature, is mounted to turn and will tend to turn in one direction against

page_text: a stop or resistance for a forward current and lock the movable contact piece
in its closed position, and to turn in the opposite direction for a return current
and release the weight, which, in falling, will move the contact piece into the
open position and so open the main or outgoing lead. The trip or releasing
device comprises according to one arrangement a lever that is connected at its
pivoted end to a catch that normally holds the weight in the raised position
and is provided at its opposite end with a short bent part or catch that normally
bears against a pin carried by a disc or arm connected to the movable coil and
core so as to turn therewith about the same centre. The point of contact
between the pin and bent end of the lever is so arranged that it is located in an
are that passes through the centre of motion of the coil and core or armature, and
has its centre at the axis about which the lever turns, and the said bent end of the
lever is so shaped that the pin can move over it in a direction to release it without
having to move the lever and connected parts. By this construction the trip device
is rendered very sensitive and reliable, as the only resistance which the coil
and core when moved backward by a return current have to overcome, is that
due to friction between the pin and lever, which is small and may he rendered
still less by placing an antifriction roller on the pin. Consequently a small
return current will suffice to effect the automatic opening of the switch or cut out.
As will be obvious cut out apparatus of the kind described can be constructed
in various forms.
Figs. 1 and 2 of the accompanying illustrative drawings are elevations at
right angles to each other, showing a return current cut-out of the kind referred
to, and Fig. 3 is a vertical section thereof partly on the line xx and partly on the
line yy of Fig. 1. Fig. 4 is a diagrammatic view.
1 is the movable switch or contact secured by a bolt 2 to an insulator 3
carried by a bar or lever 4 that is pivoted to a bracket 5 extending from an
iron base plate 6 designed to be held in a vertical position against a wall or like
support. The ends of the contact 1 are arranged to be each forced between a
nair of split metal spring contacts 7. 7", cach pair of these contacts.
being carried by an insulator 8 or 8 fixed to a raised or channelled pairt 6" of
the base plate 6, the arrangement being such that when the fixed contacts 7, 7ª
and movable contact 1 are properly engaged, the pivoted bar 4 is vertical, or
approximately so. At the outer side of the movable contact 1 is a weight 9
carried by the curved arm 10 of a lever pivoted upon the same pin 11 as the
bar 4 and the other arm 10 of which is made short and so arranged that when
the weight has been released and has, by falling, acquired some momentum,
it will strike against an abutment 4" on the bar 4 and rapidly disengage the
contact 1 from the contacts 7, 7ª.
The lever 10 is, according to this invention, normally locked or prevented
from turning, by a pivoted catch lever 12 which is held in the locking position
by a rotary body 183 which is either the armature of a rotary shunt motor, or is
connected with such armature, the connection between the catch lever and
rotary body being so constructed and arranged that no amount of pressure on
the switch operating lever 10 and consequently on the catch lever 12, will tend
to rotate the body 13 around its axis in either direction but so that when the
said rotary body is electrically rotated, it will not have to lift or do any work
on the lever. For this purpose the catch lever and rotary body may be provided,
as in the example shown in Figs. 1, 2 and 3 and diagrammatically in Fig. 4,
the one with a pin 13ª engaging a contact surface 12° on the other, the pin and
contact surface being so arranged that the direction of pressure between the
two is located in an arc that has its centre at the axis of one body and passes
through the axis of the other. and the contact surface is concentric to the axis
of the body through which the said arc passes. The rotary body 13 in the
example shown is the armature of a shunt motor, and is normally pulled in
the direction of the arrow a and held against a stop 14 by suitably weighting
the said body, or by a spring. The catch lever 12 is pivoted at 12* and provided

page_text: with a tooth or catch 12b that engages a spring catch 15 and so holds up the
weighted lever 10 which, when released, will fall and by means of the short
arm 10, strike open the switch lever 4.
Figs. 5 and 6 show diagrammatically in plan and side elevation, a modified
construction of trip mechanism of the kind referred to wherein one end of the
catch lever 12 for holding up the loaded switch operating lever 10, is caused
to bear, it may be through an antifriction wheel 12. against a horizontal
plate 13b which is connected to the motor armature of the cut-out device and is
recessed at 13°. The said plate is normally pulled in the direction of the arrow a
(Fig. 5) against a stop, so as to keep it in a position to hold down the end of
the catch lever 12 that is in contact therewith and keep the loaded switch opera-
ting lever 10 in the raised position but it can freely turn in the opposite direction
so as to bring its recessed portion 13° over the said end of the catch lever and
release it and the lever 10. In large switches, the lever 12 may advantageously
be loaded by a weight 12d so as to counterbalance to a suitable extent, the lifting
action on the catch lever of the weighted lever 10, and so reduce the pressure
and consequent friction between the catch lever and the plate 13b.
By each construction, the catch lever 12 and switch operating lever 10 will be
effectually held in the position shown when the shunt motor is out of use, and
also when traversed by normal currents, without any liability of the pin and con-
tact surface being disengaged by shock or jar, but the rotary body 13 can freely
turn in the opposite direction (see arrow b) when the normal working conditions
of the motor are no longer maintained, as in doing so it will only have to
overcome the slight friction between the pin and contact surface (Fig. 4) or
catch lever and rotary body (Fig. 5) and will not have to do any work in raising
the weighted lever 10. Consequently the connection between the armature and
catch lever whilst being very effective and reliable, is at the same time very
sensitive.
i
The shunt motor may, as in the example shown in Figs. 1, 2 and 3, be
mounted on the base plate 6. For this purpose at the lower part of the said
plate is a raised or channelled part 66 to which is secured an insulator 16
carrying a binding screw 17 for connection to a return conductor 18. The base
plate 6 is provided, between the parts 6ª, 6b, with a projecting part 6 having
a curved surface and designed to serve as a pole piece. In the space between
this pole piece and the said raised parts, is arranged a series winding 19, which
may advantageously consist of a few turns of copper tape insulated from each
other and designed to carry the greatest current the apparatus will at any time be
called upon to carry. The inner end of this winding is fixed to a metal plate 20
carried by a metal rod 21 extending from a boss 22 provided with a metal socket
piece 23 in which one end of an outgoing lead or conductor 24 can be electrically
secured. The boss 22 is carried by another insulator 25 secured to the lower
part 6 of the base plate. The plate 20, rod 21. boss 22 and socket piece 23 may
consist of a metal casting. The other end of the series winding 19 is secured to
a metal supporting piece 26 connected to a plate 27 carrying the pair of fixed
contacts 7. The plate 27ª carrying the other pair of fixed contacts 7 is formed
with a socket piece 28 in which is fixed one end of the adjoining length 24° of
out-going lead or conductor so that the winding 19 will be in series with the
two lengths of conductor. 29 is a shunt winding of fine wire wound upon the
armature 13 which is of ordinary shuttle-shaped and is mounted to turn on
knife-edges or other bearings in lugs 6d projecting from the base plate 6 and
located within the series winding 19, one end of the shunt winding being con-
nected to the series winding, as at 19ª, and the other to the insulated binding
screw 17, which, when the apparatus is to be used, is suitably connected up to
an electric circuit to constitute the winding 19 a shunt winding as well under-
stood. Over the series and shunt windings is or may be fixed an iron plate 31
having a pole piece 31° opposite to the pole piece 6° so that when the series

page_text: F
"
winding is traversed by an electric current, the iron plate will form with the
base plate, a double magnetic circuit that is completed through the armature
core, which is arranged between the pole pieces 6 and 31. The armature
core 13 and. winding 29 are normally held in about the position shown in
Fig. 3 so that the diametrical line joining the poles of the core 13 are at right
angles, or nearly so, to the diametrical line joining the pole pieces 6 and 31ª
magnétised by the series winding 19. The armature core 13 may be held in
this position against a stop 14, by a weight, or spring, preferably by 'making
the lower polar side or end of the said armature core heavier than the upper one.
As will be seen the construction of the shunt motor is such that current
flowing in a forward direction through the series winding 19 will assist the
armature weight, to hold the armature core 13 with shunt winding in the
position shown in Fig. 3, but a return current in the said series winding will
overcome the weight and turn the armature in the opposite direction sufficiently
to disengage the trip pin 13" from the end 12 of the trip lever 12, as herein-
before described, and release the lever 10, 10%, which, in falling, will strike
against the abutment 4* and effect a rapid opening of the switch.
Fig. 7 shows in elevation how the arrangement shown in Figs. 1 to 4 inclusive
can be adapted for use as an excess current cut-out. In this case the shunt
winding is removed from the armature core 13, and a spring 35 (or weight) is
provided that normally acts to hold the core 13 against a stop 36 in opposition
to the rotative action of a current of normal strength in the series winding 19,
and in such a position that the diametrical line joining the pole pieces of the
core will, as shown, form an angle of about 45° with the diametrical line joining
the polar. projections magnetised by the series winding. Upon the said series
winding being however traversed by a predetermined greater current, the
spring 35 will yield and allow the core to rotate to a small extent and cause
the pin 13 to release the trip lever 12 and permit the switch to be opened by
the falling weight, the apparatus thus acting as an excess current cut-out. The
trip lever 12 and pin 13ª are in this case so arranged, as shown, that the trip
lever will be released by forward rotation of the core 13 against the opposing
action of the spring 35 (or weight) instead of by a backward motion as in the
previous case.
。。 Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is;-
-
1. Electrical cut-out apparatus wherein a loaded switch operating lever is
prevented from moving and operating the switch proper of the cut out apparatus
by a pivoted catch lever that is held in the locking position by a rotary body
that forms the armature of a rotary shunt motor or is connected with such an
armature, the connection between the catch lever and rotary body being such
that no amount of pressure on the lever will tend to rotate the body around its
axis in either direction but so that the body can be electrically rotated without
having to lift or do any work on the said lever, whereby the cut out apparatus,
whilst being very effective and reliable, is at the same time rendered very
sensitive, as set forth.
2. Electrical cut out apparatus of the kind specified in the preceding claim
wherein the rotary body, formed by the armature 13 of a rotary shunt motor in
the cut out, or by a plate connected to such motor, has a constant tendency to
turn in one direction against a stop and is provided with a pin adapted to engage
a contact surface on the free end of the catch lever, the direction of pressure
between the pin and contact surface being located in an arc that has its centre
at the axis of the catch lever and passes through the axis of the armature or
plate, and the contact surface is concentric to the axis of the body through which
the said are passes, substantially as described and shown.

page_text: 3. Electrical cut-out apparatus constructed arranged and operating substanti-
ally as herein before described with reference to and shown in Figs. 1 to 4
inclusive, and in Fig. 7 of the accompanying drawings, or modified according to
Five 5 & 6
Dated this 11th day of November 1898.
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.