Improvements in the Method of Distribution of Electrical Energy and in Apparatus Incidental thereto.
Year: 1891

page_text: Date of Application, 17th Apr., 1891
Complete Specification Left, 18th Dec., 1891-Accepted, 5th Mar., 1892
PROVISIONAL SPECIFICATION.
Improvements in the Method of Distribution of Electrical Energy
and in Apparatus Incidental thereto.
I, SEBASTIAN ZIANI DE FERRANTI, of 120 Fellows Road, Hampstead, in the
County of Middlesex, Electrician, do hereby declare the nature of this invention
to be as follows
―:
When carrying out on a fairly large scale my system of electrical distribution,
I prefer to place the generating station at some convenient locality outside the
district of supply, and transmit a high tension current to convenient points within
the district and there transform it to a low tension.
Up to now in all high tension systems, a transformer with its high tension
fuses, etc. has usually been installed in the house of each customer requiring light,
but in my present system I do away with this inconvenience.
I now establish in
every district one, or more, sub, or distributing stations, located at a convenient
distance apart, and instal therein large sized converters connected in parallel or
banked as specified in my former Patent No. 15251 in the year 1885, of a total
capacity equal to the demand of the district, together with a suitable reserve set;
the converters being arranged so that the high tension current of 2,400 volts,
10,000 volts, or other suitable voltage on arriving from the generating station
should be transformed down to 100 volts, 200 volts, or other convenient pressure.
Preferably, when the low tension distribution is made on the two, or three wire
system transform in each converter direct from 10,000 volts to 100 volts, but in
some districts where a proportion of the buildings to be lighted are scattered, it is
necessary to have some converters transforming from 10,000 volts to 2,400 volts,
to distribute at this pressure, and again transform at the customers' houses to
100 volts as in the present practice.
Each sub-station make throughout of fireproof construction, the electrical
apparatus is supported at such a distance away from the walls, etc. that no electrical
are can be formed between the apparatus and the walls, or could continue to exist
even if so formed.
The entire apparatus is so split up and divided and partitioned off by slate or
other non-combustible non-conducting separators, that in the event of one portion
of the apparatus being damaged, the adjacent portious would be uninjured.
The drawing annexed is a diagram showing a general arrangement of the
switching gear, fuses, etc., on the walls of such a sub-station in which the current is
transformed.
A is a concentric tubular main with its outside copper conductor insulated and
protected by a steel tube. Being usually laid underground it enters the distributing
station through the floor as shewn. The outer steel tube is removed at the point A,
and the outer Ferranti compound insulation at the point A³, leaving the outer
copper conductor bare from A to A. On this conductor is mounted two discon-
necting terminal blocks I and 1. From A to A the outer copper conductor is
removed leaving the inside insulation exposed, and on this insulation is mounted a
compound ebonite insulator, not shown. At A' the insulation is cut away to the
internal copper conductor on which is screwed the plug switch contact terminal B,
the two contact lugs allowing connection to be made respectively at the right and
left hand by removable plug switches J. The whole of the switching gear, fuses,
connecting cables, etc., are entirely insulated from the walls of the building. We
will consider the left hand circuit first. On the left hand side of B is fixed fuse
end connection supporting the lower end of fuse F, connection between C and B
being made by a movable plug switch not shewn in diagram.

page_text: E, a cast iron bracket, the upper portion being cemented or otherwise securely
attached into the ceiling of the distributing station and holding the top fuse
holder D. Connection between D and C, and D and G is made by the fuses F.
Gis similar in general construction to C being connected to II, a small pilot
converter transforming from 10,000 volts to 100 volts and used for indicating at
the sub-station the tension that is on the mains, and for lighting the station, etc.
The high tension current on leaving the converter passes to terminal block I,
which is securely attached to the outside conductor of concentric main A.
divided in two halves, connection between which is made by a metal plug.
I is
As is well known, in my system, the outer conductor of the concentric cable is
connected to earth in the generating station at the dynamo, and is consequently
called an earth pole, but as the distance between a distributing station and the
generating station may be several miles, there will be a difference of potential
between the outer conductor at the distributing station and the earth, due to the
resistance of the cable, and if connected together current would consequently pass.
It is therefore necessary at the distributing station to maintain the outer conductor
insulated from earth, and thus prevent any difference in the currents flowing
respectively in the inner and outer conductors and consequent induction on
telegraph, telephone, and other wires.
On the right hand side of B is K one of the contact lugs of the high tension
switch L, connection between B and K being made by a plug switch not shown.
The current passes through L on to K, through a plug switch (not shown) to M,
thence through another plug switch N, to ammeter holder O, and through the
ameter to P, a high tension switch for each individual converter. The circuit
through P being made the current passes to Q, a top fuse holder, and thence
through a fuse similar to F, on to the high tension terminal of the converter.
The other converter terminal is connected by an insulated copper conductor to R,
through contact strips S of switch P, to T, thence through an insulated copper
conductor to I' which is similar to terminal block 1. As will be seen from diagram
the current on reaching O has an alternate path through U on to 01, etc., etc., and
thus through No. 2, 3 &c. &c. converter.
On the low tension side of the converter the insulated terminal is connected by
a fuse similar to F, on to contact lug Q, through contact strips of switch P to
ammeter holder O, through the ammeter holder and plug switch V on to contact
lug W, thence through a plug switch, not shewn, on to contact block X, which is
fixed on to the internal conductor of the concentric cable leading to the circuit
switches. The low tension earth pole is directly connected by a copper conductor
to Y, thence through contact strips S¹, of switch P, to T, and through a plug
switch not shown to terminal Z, fixed on to the external conductor of the concentric
cable.
The current received by the converter on the high tension side, and the amount
delivered on the low tension side are thus clearly shewn by the ammeters, and the
condition of the converter, and the amount of work performed at any moment is
easily ascertained.
Although not shewn on the diagram, the high tension switch L, main A, fuses F,
converter etc., are repeated on the right hand side so that the whole of the
apparatus forms a divided ring, and thus the whole of the converters may be fed
from the mains at either or both ends or some from one end and some from the
other which can be connected in parallel at the generating station, or be supplied
by separate dynamos, the connections of the converters, e, in the form of a ring
as shown, allowing this to be done with the greatest case, LA and L A² can be
joined in parallel or fed separated as desired, thus allowing the circuit switches to
be fed separately or in parallel.
If it is desired to entirely disconnect the converters at a sub-station from either
or both of the mains from the generating station, this can be effected by means of
the two four foot break switches L. In the event of any accident happening to
either of the pilot converters H, they would be automatically cut out of circuit by

page_text: the fuses F, and can be at any time disconnected from the circuit for cleaning or
repairs by removing the plug switch between B and C, and the plug in 1.
This also applies to all and any of the separate converters No. 1, 2, 3, &c., and
their gear for switching all or any part of which can be cut out of circuit by the
removal of the proper plug and disconnecting switches.
The converters are ranged in a row parallel with the wall which carries the
switch contact apparatus.
Each converter is clamped within a frame which can
be run on rails towards or away from the wall so as either to bring it into or out
of acting position. When run into acting position contacts upon it connect its
terminals which are to be put to earth (or return conductor) with earth connections
of the switching gear which is mounted upon the wall as above described.
The switching gear I construct in such manner that whenever any one or other
of the converters is to be brought into use the carth or return connections of both
the high and low tension mains are made first and afterwards the insulated con-
ductors and conversely when the converter is to be put out of use the insulated
connections are first broken and then the earth connections-thus it will always
be safe to touch the casing and iron of the converter when it is running as it is
always connected to earth.
The two converter terminals which when the converter is in use have to be put
in connection with the high and low tension mains respectively are on the top of
the frame which carries the converter. They are made cup shaped and with the
bottom of the cup loose and pressed forwards by a spring. One of these is con-
nected by a fuse with contact lug Q the other with the contact lug Q. Each
fuse make preferably of a long glass tube with metallic ends and with the fuse
wire passing through the tube from one metallic end to the other. One metallic
end is made to rest in the hollow of a spoon shaped projection on the contact lug
the other on the spring bottom of the cup terminal on the converter-the spring
so serving to hold the fuse in place.
The switching gear I use for putting the converters into or out of action I form
in the following manner. The contact strips P which are to couple O* with Q
and Qwith O are carried by ebonite arms from a block which can be slidden to
and fro along a bar which projects out horizontally from the wall. At the side of
the block is an inclined cam groove having its front and rear ends horizontal. A
rod with a handle at its end extends forwards from the block and by this handle
the block can be moved towards or away from the wall.
The contact strips S S' which are to connect R with T and T' with Y are carried
by a vertical slide which can be raised and lowered through guides in brackets
which stand out from the wall. The upper end of the slide is coupled by a con-
necting rod with one arm of a lever the opposite arm of which carries a weight
which tends always to raise the vertical slide and to carry the contact strips away
from R T and TY. The weight has a pin carrying a roller standing out from its
side. When the block which carries the contact strips is slidden towards the wall
the front end of the cam groove at the side of the block comes up to the roller and
the roller enters the groove. As the block continues to be moved towards the
wall the inclined portion of the groove causes the weight to be lifted and con-
sequently depresses the vertical slide which carries the contact strips S Sand
brings these strips between R T and T Y and so makes the earth connections.
Afterwards by the continued movement of the block towards the wall the ends of
the contact strips Pare brought into the fixed contact lugs O* Q and Q¹ O³.
Horizontal slabs of slate or other non conducting incombustible material are
made to stand out from the wall to form partitions below the high tension conductor
below the high tension switch and below the low tension switch so that even if an
arc should occur it would be confined and could do but little damage.
The break switch for connecting the fixed contact lug K with the fixed contact
lug Kform of a pair of vertical rods tied together at a distance apart by
horizontal bars and sliding through guide holes in arms extending from a cast iron
plate secured to a wall.

page_text: Ebonite rods are made to extend upwards from the top of the vertical rods
and ebonite rings are made to surround the ebonite rods so as to form projecting
flanges around them-gun metal caps are secured on the top of the ebonite rods to
which are secured two parallel horizontal brass strips and also a strong steel spring
blade lying between them.
Two metal jaw pieces for the ends of the horizontal brass strips to be slidden into
are carried by ebonite stems extending out from blocks let into the wall and ebonite
discs are made to surround the ebonite stems-a notched catch is also fixed to each
jaw piece.
When the vertical rods are raised to their highest position the ends of the hori-
zontal conducting strips come between the two fixed metal jaw pieces and make
contact between them. The ends of the steel spring also come above the top of
the catch pieces-the lower part of the catch pieces being inclined so that the ends
of the spring coming against these inclines the spring is bent downwards until the
ends have passed the inclines the spring then straightens out and its ends come
above the top of the fixed catch pieces.
When the vertical rods are raised to their highest position they are upheld by a
spring catch. By pulling downwards a lever handle the catch can be released-
the vertical metal rods carrying the conducting strips then drop and the ends of
the conducting strips move down away from the fixed jaw pieces but the ends of the
spring still remain in contact with the catch pieces on the jaws and the current
passes momentarily through the spring.
When the vertical rods have acquired momentuin and the ends of the conducting
strips are at such a distance from the jaw pieces that there is no possibility of an
are striking or forming between them the final contact is instantaneously broken by
the spring having become so bent that its ends get clear of the fixed catch pieces-
the spring then straightens and leaves the catch pieces rapidly. Thus any are that
may occur is formed between the spring and the catch pieces both of which are
arranged to be rapidly replaceable at a trifling cost. The switches for con-
necting Ox with Qand Q with O' I form in the same manner so as to avoid the
formation of an are between these points and the contact strips P as the contacts
are broken.
The circuit switches for controlling the supply of current to each separate
distributing cable are fed with current from conductors ranged in the form of a
divided ring and themselves fed at each end with current from converters.
The circuit switches are quite distinct from and can be at a distance from the
converter switching gear either in the same or a separate building.
The switching gear for the several cables is carried between parallel vertical walls
of slate or other incombustible insulating material-these may be ranged around
the sides of a room. In each space is mounted switching gear for one cable.
The space between these walls is divided by a central wall or partition at right
angles to the others.
At each end of the divided ring of stalls or compartments so formed the con-
ductor which is to supply current is made to rise up from the floor. Preferably a
concentric tubular conductor is used. At the top the inner conductor is coupled
by a plug switch with a gun metal terminal block which forms the lower contact of
switch.
This contact block is also coupled by a plug switch with the lower switch contact
block in the next compartment and so on.
The lower switch contact in each compartment is carried by two ebonite rods
which pass across from a plate secured to one side wall to a plate secured to the
other. Other plates secured at a higher level to the side walls carry bearings to
receive the ends of an ebonite rod which carries the moveable portion of the switch
the rod is embraced by a gun metal casting to which are secured brass con-
ducting strips for making contact with the jaws of the top and bottom fixed
contacts and steel springs for breaking final contact as in the break switch above
described.

page_text: The casting has also an arm extending from it to which is connected a handle
by which the moveable portion of the switch can be turned into position to make or
break contact.
The block which carries the jaw pieces of the upper switch contacts is like the
lower contact block carried by ebonite rods which pass across from a wall plate
secured to one side wall to a wall plate on the other wall. Each block is divided
vertically into two parts these are bolted together with insulation between. The
upper part of the block is formed to receive an ameter. One terminal of the
ameter is coupled to a terminal on the front half of the block the other to a terminal
on the back half. The ameter is held down into this holder by a cap piece and
bolts. The front half of the lower part of the block has the jaw pieces for the
upper switch contact formed with it." The back half is suitably formed for a fuse
connection to be secured to it.
The current is led through the ameter from the front half of the block to the
back half.
The block is centrally above the top of the cross dividing wall so that the fuse
connection is in rear of this wall.
The block which carries the lower fuse connection is carried by ebonite rods and
wall plates in the same way as the other contacts the arm which carries this fuse
connection has formed through it a conical socket to receive a corresponding stem
the lower end of which is hollowed for the end of one of the distributing cables to
be sweated or otherwise secured into it.
The fuse itself is formed and held between its upper and lower contacts just in
the same way as the other fuses before mentioned.
The insulation between the inner and outer conductor of the distributing cable
is coned away at the end and can be fittel with ebonite or other insulator if
desired.
Connection between the outer conductors is made with the return ring conductor
by means of terminal blocks the several sections of which are electrically joined
together or can be disconnected by means of removable plugs whenever necessary
for testing.
Over the top of the whole of the slate separators of the above switches and at a
distance of about 12 inches from the top of the slates fix a horizontal slate of
sufficient size to cover the whole of the switches and prevent water or other
substance from falling from the ceiling on to the switches and so damaging them―
it is also useful to prevent the continuance of an are and for other purposes.
It will be seen that the arrangement described provides for the disconnecting at
will of both the inside and outside conductors of each separate distributing cable,
for testing and other purposes, and this without in the least disturbing any of the
adjacent cables, etc., and as the switches are all partitioned off by slate separators,
any are forming on one switch cannot be conveyed to an adjacent one.
I do not confine myself to the exact materials mentioned, but may use any
suitable for my purpose-and similarly I do not confine my switching gear, and
converter banking &c. to transformers connected all in parallel on both the high
and low tension sides, but may by slight modifications in the details of my inven-
tion arrange to couple them in the manner most convenient and suitable for the
work to be donc.
The movable portion of each plug switch is formed of a handle of ebonite,
conveniently shaped for holding, on either side of which is bolted a spring brass
strip which at its two ends is split in three places to give greater spring and
certainty of contact with the fixed contact lugs. The two strips are bent so as to
tend to come together, and are kept apart by a distance screw tapped in the upper
strip, and butting against the lower one.
Dated this 17th day of April 1891.
CARPMAEL & Co.,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in the Method of Distribution of Electrical Energy
and in Apparatus Incidental thereto.
I, SEBASTIAN ZIANI DE FERRANTI, of 120 Fellows Road, Hampstead, in the
County of Middlesex, Electrician, 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 :-
When carrying out on a fairly large scale my system of electrical distribution, I
prefer to place the generating station at some convenient locality outside the
district of supply, and transmit a high tension current to convenient points within
the district and there transform it to a low tension.
Up till now in all high tension systems, a transformer with its high tension
fuses, etc., has usually been installed in the house of each customer requiring light,
but in my present system 1 do away with this inconvenience. I now establish in
every district one or more, sub-, or distributing stations, located at a convenient
distance apart, and instal therein large sized converters connected in parallel or
banked as specified in my former Patent No. 15251 in the year 1885 of a total
capacity equal to the demand of the district, together with a suitable reserve set ;
the converters being arranged so that the high tension current of 2,400 volts,
10,000 volts, or other suitable voltage on arriving from the generating station
should be transformed down to 100 volts, 200 volts, or other convenient tension.
Preferably when the low tension distribution is made on the two, or three wire
system transform in each converter direct from 10,000 volts to 100 volts, but in
some districts where a proportion of the buildings to be lighted are scattered, it is
necessary to have some converters transforming from 10,000 volts to 2,400 volts, to
distribute at this pressure, and again transform at the customers' houses to 100 volts
as in the present practice.
Each sub-station make throughout of fireproof construction, the electrical
apparatus is supported at such a distance away from the walls etc., that no electrical
are can be formed between the apparatus and the walls, or could continue to exist
even if so formed.
The entire apparatus is so split up and divided and partitioned off by slate or
other non-combustible non-conducting separators, that in the event of one portion
of the apparatus being damaged, the adjacent portions would be uninjured.
On Sheet I of the drawings annexed is a diagram showing a general arrange-
ment of the switching gear, fuses, etc., on the walls of such a sub-station in which
the current is transformed.
A is a concentric tubular main with its outside copper conductor insulated and
protected by a steel tube. Being usually laid underground it enters the distributing
station through the floor as shewn. The outer steel tube is removed at the
point A', and the outer Ferranti compound insulation at the point A', leaving the
outer copper conductor bare from A to A³. On this conductor is mounted two
disconnecting terminal blocks I and I. From A³ to A' the outer copper conductor
is removed leaving the inside insulation exposed, and on this insulation is mounted
a compound ebonite insulator, not shown. At A' the insulation is cut away to the
internal copper conductor on which is screwed the plug switch contact terminal B,
the two contact lugs allowing connection to be made respectively at the right and
left hand by removable plug switch J. The whole of the switching gear, fuses,
connecting cables etc., are entirely insulated from the walls of the building. We
will consider the left hand circuit first. On the left hand side of B is fixed fuse
end connection C supporting the lower end of fuse F', connection between C and B
being made by a movable plug switch J.
E, a cast iron bracket, the upper portion being cemented or otherwise securely
attached into the ceiling of the distributing station and holding the top fuse

page_text: holder D which is thoroughly insulated from E. Connection between D and C,
and D and G is made by the fuses F.
G is similar in general construction to C being connected to H, a small pilot
converter transforming from 10,000 volts to 100 volts and used for indicating at the
sub-station the tension that is on the mains, and for lighting the station, etc.
The high tension current on leaving the converter passes to terminal block I.
which is securely attached to the outside conductor of concentric main A. I is
divided in two halves, connection between which is made by a metal plug.
As is well known, in my system, the outer conductor of the concentric cable is
connected to earth in the generating station at the dynamo, and is consequently
called an earth pole, but as the distance between a distributing station and the
generating station may be several miles, there will be a difference of potential
between the outer conductor at the distributing station and the earth, due to the
resistance of the cable, and if connected together current would consequently pass.
It is therefore necessary at the distributing station to maintain the outer conductor
insulated from earth, and thus prevent any difference in the currents flowing
respectively in the inner and outer conductors and consequent induction on telegraph,
telephone and other wires.
On the right hand side of B is K one of the contact lugs of the high tension
switch L, connection between B and K being made by a plug switch J. The
current passes through L on to K, and through a plug switch J to M, thence
through another plug switch, N to an ammeter holder O, and through the ammeter
to P, a high tension switch for each individual converter. The circuit through P
being made the current passes to Q, a top fuse holder, and thence through a fuse
similar to F, on to the high tension terminal of the converter.
The other con-
verter terminal is connected by an insulated copper conductor to R, through
contact strips S of switch P, to T, thence through an insulated copper conductor
to which is similar to terminal block 1. As will be seen from diagram the
current on reaching O has an alternate path through U on to O 1, etc., etc., and
thus through No. 2, 3 &c. &c. converter.
On the low tension side of the converter the insulated terminal is connected by
a fuse similar to F, on to contact lug Q, through contact strips of switch P to
ammeter holder O³, through the ammeter holder and plug switch on to contact
lug W, thence through a plug switch J, on to contact block X, which is fixed on
to the internal conductor of the concentric cable leading to the circuit switches.
The low tension earth pole is directly connected by a copper conductor to Y,
thence through contact strips S', of switch P' to T, and through a plug switch J
to terminal Z, fixed on to the external conductor of the concentric cable.
The current received by the converter on the high tension side, and the amount
delivered on the low tension side are thus clearly shewn by the ammeters, and the
condition of the converter, and the amount of work performed at any moment is
easily ascertained.
Although not shewn on the diagram the high tension switch L, main A, fuses F,
converter etc., are repeated on the right hand side of diagram so that the whole of
the apparatus forms a ring, main, divisible at will and thus the whole of the con-
verters may be fed from the main at either or both ends or some from one end
and some from the other and the mains can be connected in parallel at the
generating station, or be supplied by separate dynamos, similarly the connections
on the low tension side of the converters being in the form of a ring as shown,
allows cable L A' conveying current to the circuit switches to be joined in parallel
with the corresponding conductor at the opposite end or be fed separately as
desired, thus allowing the circuit switches to be fed off independent circuits or in
parallel.
If it is desired to entirely disconnect the converters at a sub-station from either
or both of the mains from the generating station, this can be effected by means of
the two four foot break switches I one at each end of the divided ring. In the
event of any accident happening to either of the pilot converters H, they would be

page_text: automatically cut out of circuit by the fuses F, and can be at any time disconnected
from the circuit for cleaning or repairs by removing the plug switch between B
and C, and the plug in I.
This also applies to all and any of the separate converters Nos. 1, 2, 3 &c., and
their gear for switching all or any part of which can be cut out of circuit by the
removal of the proper plug and disconnecting switches.
The construction of the break switch for connecting the fixed contact lug K
with the fixed contact lug K is shown on Sheets 2 and 3.
Figure 1 is a front elevation and Figure 2 a side elevation of the break switch,
Figure 3 a plan of one of the contacts which is fixed in the wall. Figure 4 a
section through the line ab Figure 3. Figure 5 an end view of one of the cast
iron blocks which is fixed in the wall to carry the contact piece. Figure 6 is a
plan view of the break switch, with the contact bar L and the rods which carry it
removed. Figure 7 is a section through ed Figure 6. Figures 8 are detail views
of the handle used for lifting the contact bar L and the catch which holds it
when lifted. Figures 9 are detail views of the bar by which this handle and catch
are carried.
As shown in these figures the break switch is formed of a pair of vertical rods a
tied together at a distance apart by horizontal bars a' a² and sliding through guide
holes in arms extending from a cast iron plate & secured to a wall.
Ebonite rods a are made to extend upwards from the top of a' and cbonite rings at
are made to surround the ebonite rods so as to form projecting flanges around
them. On the top of the ebonite rods are secured gun metal caps as to which are
secured two parallel horizontal brass strips L and also a strong steel spring blade ¹
lying between them.
Two metal jaw pieces c for the ends of the horizontal brass strips L to be slidden
into are carried by ebonite stems e extending out from blocks let into the wall
and ebonite discs c are made to surround the cbonite stems-a notched catch c' is
also fixed to each jaw piece.
c and
When the vertical rods are raised to their highest position the ends of the
horizontal conducting strips L come between the two fixed metal jaw pieces
make contact between them. The ends of the steel spring also come above the
top of the catch pieces c-the lower part of the catch pieces being inclined so that
the ends of the spring coming against these inclines the spring is bent downwards
until the ends have passed the inclines, the spring then straighteus out and its ends
come above the top of the fixed catch picces.
When the vertical rods are raised to their highest position they are upheld by a
spring catch catching over a stop d* on the upper pair of arms b. By pulling
downwards a lever handle e the catch can be released-the vertical metal rods a
carrying the conducting strips L then drop and the ends of the conducting strips
move down away from the fixed jaw pieces e but the ends of the spring still
remain in contact with the catch pieces e on the jaws and the current passes
momentarily through the spring. When the vertical rods have acquired momentum
and the ends of the conducting strips are at such a distance from the jaw pieces
that there is no possibility of an are striking or formning between them, the final
contact is instantaneously broken by the spring having become so bent that its ends
get clear of the fixed catch pieces-the spring then straightens and leaves the catch
pieces rapidly. Thus any are that may occur is formed between the spring and the
catch pieces both of which are arranged to be rapidly replaceable at a trifling
are spring stop for the caps a to drop onto to avoid shock. It will be
seen that the handle e and spring catch d are both jointed to the lower bar a² which
is secured to the vertical rods a. The catch is pressed towards the wall by a
spring and the handle is pressed upwards by a spring ex. The movement given
to the catch by the spring is limited by the tail end of the catch coming against a
stop e on the handle. The upward movement of the handle is limited by an
arme upon it coming against the bar a². In this way it will be seen that when
the handle e is lifted the catch d is free to spring back so as to pass and then catch
co-t.

page_text: the manure is paned downwards the Catch is
and released from this stop.
As an additional security for the switch room operator, handle e is covered with
ebonite e, on which is mounted ebonite insulator disc e*.
The switches for connecting 0 with Q and Q' with O³ I form in the same
manner so as to avoid the formation of an are between these points and the contact
strips P as the contacts are broken.
The converters are ranged in a row parallel with the wall which carries the
switch contact apparatus as shown at Figures 10 and 11. Figure 10 is a plan view
and Figure 11 a side elevation. Figure 12 is a side elevation of part of one of the
converters and its stand. Figure 13 is a front elevation of the same. Figure 14
is a front view of the stand partly in section. Figures 15 and 16 shew details of
part of the contact mechanism. Figure 17 is a face view of part of the wall
shewing the contact mechanism for one converter on a larger scale than in the
diagram Sheet 1. Figures 18 shew one of the fuses. Figures 19 to 23 show
details of the switching gear. Figures 24, 25 and 26 shew the construction of the
ammeter holder.
Each converter is clamped within a frame which can be run on rails or over
rollers on to a fixed stand towards or away from the wall so as either to bring
it into or out of acting position. When run into acting position contacts upon it
connect its terminals which are to be put to earth (or return conductor) with
earth connections joined to the switching gear which is mounted upon the wall as
above described.
The switching gear I construct in such manner that whenever any one or other
of the converters is to be brought into use the earth or return connections of both
the high and low tension mains are made first and afterwards the insulated
conductors and conversely when the converter is to be put out of use the insulated
connections are first broken and then the earth connections-thus it will always be
safe to touch the casing and iron of the converter when it is running as it is always
connected to earth.
On each side of the stand is a contact brush fand on each side of the
frame of the converter is a contact plate which when the converter is run into
position comes against the brushes -one contact is coupled to the return
end of the primary winding of the converter the other to the return end of the
secondary.
One brush is coupled to terminal on R Fig. 17 the other brush is coupled to
terminal on Y.
The two converter terminals g Fig. 11 which when the converter is in use have
to be put in connection with the high and low tension mains respectively are on
the top of the frame ƒ which carries the converter. They are made cup shaped
and with the bottom of the cup loose and pressed forwards by a spring see
Figure 11. One of these is connected by a fuse with contact lug Q the other
with the contact lug Q. Fig. 32 shows in plan, and partial side elevation, the
details of Q & Q Each fuse make preferably of a long glass tube with
metallic ends and with the fuse wire passing through the tube from one metallic
end to the other such a fuse is shewn at Figures 18. One metallic end is made to
rest in the hollow of a spoon shaped projection on the contact lug the other on the
spring bottom of the cup terminal on the converter-the spring so serving to hold
the fuse in place.
The switching gear I use for putting the converters into or out of action I form
in the following manner. The contact strips P which are to couple O* with Q
and Q' with Oare carried by ebonite arms i see Figures 11 and 17 from a block j
which can be slidden to and fro along a bar K which projects out horizontally from
the wall. At the side of the block is an inclined cam groove having its front
and rear ends horizontal. A rod with a handle preferably of ebonite at its end
extends forwards from the block and by this handle the block can be moved
towards or away from the wall.

page_text: The contact strips S S¹ which are to connect R with T and T' with Y are carried
by a vertical slide which can be raised and lowered through guides in brackets
which stand out from the wall. The upper end of the slide is coupled by a
connecting rod with one arm of a lever the opposite arm of which carries a
weight which tends always to raise the vertical slide 2 and to carry the contact
strips away from RT and T' Y. The weight has a pin carrying a roller
standing out from its side. When the block which carries the contact strips is
slidden towards the wall the front end of the cam groovej at the side of the block
comes up to the roller and the roller enters the groove. As the block continues to
be moved towards the wall the inclined portion of the groove causes the weight l
to be lifted and consequently depresses the vertical slide which carries the contact
strips S S and brings these strips between R T and T Y and so makes the earth
connections.
Afterwards by the continued movement of the block j towards the
wall the ends of the contact strips P are brought into the fixed contact lugs O* Q
and Q' O'.
Horizontal slabs of slate m or other non-conducting incombustible material are
made to stand out from the wall to form partitions below the high tension con-
ductor below the high tension switch and below the low tension switch so that
even if an arc should
occur it would be confined and could do but little
damage.
The details of ammeter O are shown in Figures 24, 25 and 26. 1 is a cast iron
wall block with fluted sides and is cemented into the walls of the distributing
station and into it is screwed and pinned, ebonite rod 2, fitted with ebonite insulator
rings 3, and ammeter bracket 4, and ammeter clamps 5. The large ring forming
the centre of 5 is fitted with a circular ammeter the case of which is insulated by
a strip of fibre, or other suitable material. The ring is divided horizontally at
the centre, the two halves being held together by screws 6 tapped into the upper
half but insulated from the lower half. The two terminals of the ammeter are
connected by flexible cable respectively with terminal 7 on the upper half clamp,
and terminal 8 on the lower half clamp.
The lower shank of amineter clamp 5 is turned taper and fits into a corre-
sponding cone in bracket 4, being held in place by a thumb screw and washer 9.
By this means the ammeter and clamp can be removed rapidly from place for
calibration, repairs, etc.
The circuit switches for controlling the supply of current to cach separate
distributing cable are fed with current from conductors ranged in the form of
a divided ring and themselves fed at each end with current from converters.
The circuit switches are quite distinct from and can be at a distance from the
converter switching gear either in the same or a separate building.
The switching gear for the several cables is carried as shewn at Figures 27, 28, 29
and 30 between parallel vertical walls of slate or other incombustible insulating
material these may be ranged around the sides of a room.
In each space is
mounted switching gear for one cable. Figure 27 is a vertical section. Figure 28
a front view. Figure 29 a plan and Figure 30 a part back elevation. Figures 31
to 34 shew separately some of the parts. The vertical walls are marked n.
The space between these walls is divided by a central wall or partition o at right
angles to the others.
At each end of the divided ring of stalls or compartments so formed the
conductor which is to supply current is made to rise up from the floor.
Preferably a concentric tubular conductor is used. At the top the inner conductor
is coupled by a plug switch q with a gun metal terminal block r which forms the
lower contact of switch.
This contact block is also coupled by a plug switch 7 with the lower switch contact
block in the next compartment and so on.
The lower switch contact in each compartment is carried by two ebonite
rods which pass across from a plate secured to one side wall to a plate secured
to the other. Other plates s secured at a higher level to the side walls carry

page_text: bearings to receive the ends of an ebonite rod s' which carries the moveable portion
of the switch-the rod is embraced by a gun metal casting to which are secured
brass conducting strips for making contact with the jaws of the top and bottom
and steel springs for breaking final contact as in the break
fixed contacts
switch above described.
The casting has also an arm extending from it to which is connected an insulated
handle by which the moveable portion of the switch can be turned into position
to make or break contact.
The block which carries the jaw pieces of the upper switch contacts is like the
lower contact block carried by ebonite rods to which pass across from a wall plate t
secured to one side wall to a wall plate on the other wall. Each block is divided
vertically into two parts as shewn best in Figure 27 these are bolted together with
insulation between. The upper part of the block is formed to receive an
ammeter u. One terminal of the ammeter is coupled by flexible cable to a
terminal on the front half of the block the other to a terminal on the back half.
The ammeter is held down into this holder by a cap piece and bolts. The front
half of the lower part of the block has the jaw pieces for the upper switch contact
formed with it. The back half is suitably formed for receiving the upper end of a
fuse r.
The current is led through the ammeter from the front half of the block to the
back half.
The block is centrally above the top of the cross dividing wall so that the fuse
connection is in rear of this wall.
The block which carries the lower fuse connection is carried by ebonite
rods and wall plates in the same way as the other contacts- the arm which carries
this fuse connection has formed through it a conical socket to receive a corre-
sponding stem the lower end of which is hollowed for the end of one of the
distributing cables to be sweated or otherwise secured into it.
The fuse v itself is formed and held between its upper and lower contacts just in
the same way as the other fuses before mentioned.
The insulation between the inner and outer conductor of the distributing cable
is coned away at the end and can be fitted with ebonite or other insulator if
desired.
=
Connection between the outer conductors is made with the return ring conductor y
by means of terminal blocks the several sections of which are electrically joined
together or can be disconnected by means of removable plugs whenever necessary
for testing.
Over the top of the whole of the slate separators of the above switches and at a
distance of about 12 inches from the top of the slates I fix a horizontal slate not
shewn in the drawing of sufficient size to cover the whole of the switches and
prevent water or other substance from falling from the ceiling on to the switches
and so damaging them-it is also useful to prevent the continuance of an arc and
for other purposes.
It will be seen that the arrangement described provides for the disconnecting at
will of both the inside and outside conductors of each separate distributing cable,
for testing and other purposes and this without in the least disturbing any of the
adjacent cables, etc, and as the switches are all partitioned off by slate separators,
any are forming on one switch cannot be conveyed to an adjacent one.
I do not contine myself to the exact materials mentioned, but may use any
suitable for my purpose and similarly I do not confine my switching gear, and
converter banking &c. to transformers connected all in parallel on both the high
and low tension sides, but may by slight modifications in the details of my invention
arrange to couple them in the manner most convenient and suitable for the work
o be done.
The movable portion of the plug switches q Figure 34 may be formed of a
haudle of ebonite conveniently shaped for holding, on either side of which is

page_text: bolted a spring brass strip which at its two ends is split in three or more places to
give greater spring and certainty of contact with the fixed contact lugs. The two
strips are bent so as to tend to come together, and if desired may be kept
apart by a distance screw tapped in one brass side strip and abutting against the
other one.
Figure 3 shews method of construction of plug switches U and V, Figures 1
and 17 forming respectively parts of the high and low tension ring mains the removal
of which enables the main to be split into sections.
p is a portion of a Ferranti concentric main with its outer conductor removed.
The insulation is coned at each end and on this coned portion is mounted an
ebonite insulator pl.
A casting 2 screwed on the inner tube carries two spring brass strips similar in
all respects to those on plug switch Figure 34.
q
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The general construction and arrangement of a distributing station sub-
stantially as hereinbefore described.
2. In a distributing station the combination of 4 parallel conductors one above
the other, the converters in a row in front of the conductors, and the switching
gear opposite to each converter to couple its terminals to the conductors substantially
as described.
3. In a distributing station the combination of the 4 parallel conductors,
the converters and the switching gear the two primary conductors being fed with
current at each end and the two secondary feeding from each end to each end of a
system of circuit switching gear substantially as described.
4. In a distributing station the combination of the parallel conductors carried one
above the other by a wall, the converters and the switching gear and slabs of slate
or other non-conducting material standing out from the wall below and between the
conductors substantially as described.
5. In a distributing station the separation of the electrical mains by slabs of slate
or other non-combustible material substantially as described.
6. In a distributing station the separation of the converters, the mains, and
switch mechanism by slabs of slate or other non-combustible material substantially
as described.
7. The combination of converter stand, converter and switch mechanism in such
manner that the running into place of the converter on to the stand makes contacts
with the switch mechanism such as when fuses for the high and low tension coils
have been put into place permit of the converter being put into or out of action by
the movement of the switch bars.
8. Converter switch mechanism so constructed that by the movement of one
handle the earth ог return connections of both the high and low tension
mains are made previous to making the connections with the insulated con-
nections and so that the converse takes place when the handle is moved in the
opposite direction.
9. Converter switch mechanism so constructed that the earth or return connections
of both the high and low ten-ion mains aust ncessarily be made before making
connection with the insulated conductors.
10. In a system of electrical distribution the insulating at the distributing station
of a conductor put to earth at the dynamo end.
11. In a distributing station the combination with a circuit conveying high
tension electricity of insulated switch gear held at a distance from a wall with
the insulation support held in brick slate concrete or other non-combustible non-
conducting material so that a short circuit to earth cannot occur if insulation of
the support fails.

page_text: 12. Circuit switching gear with fuse gear at the back and separated from
the switching gear by partitions of slate or other insulating material substantially
as described.
13. The construction of converter switching gear substantially as hereinbefore
described.
14. The construction of circuit switching gear substantially as herein before
described.
15. An electrical switch with spring which continues for a time to make contact
between the fixed and movable portions as they are being moved away from one
another and when they are at a sufficient distance apart springs rapidly out of
contact substantially as described.
16. The construction of electrical switches substantially as hercinbefore
described.
17. The construction of fuse and fuse supports substantially as hereinbefore
described.
18. The combination of ammeters held at a distance from the walls on both the
high and low tension side of a converter, substantially as described.
19. At a distributing station earthing one pole of the low tension side of one or
more converters the corresponding pole or poles on the high tension side being also
earthed.
20. In a distributing station the combination of removable plug or disconnecting
switches with what is herein called a ring main thus allowing the ring to be split
into sections.
21. The construction of the ammeter holders for the converter switches sub-
stantially as herein before described.
22. The construction of the ammeter holders for the circuit switching gear
substantially as described.
23. The construction of the movable plug switches substantially as illustrated and
described.
24. The combination of an insulated electric conductor tapered or coned, at its
end and an ebonite or other insulator with or without corrugation tapered or coned
reciprocally substantially as described with reference to Figure 31.
25. The combination with a plug switch of a set or distance screw for regulating
the distances of the brushes or contact strips.
Dated this 18th day of December 1891.