Improvements in connection with the Construction and Working of Transformers or Converters.
Year: 1891

page_text: Date of Application, 20th June, 1891
Complete Specification Left, 21st Mar., 1892-Accepted, 18th June, 1892
Improvements in connection with the Construction and Working of
Transformers or Converters.
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:-
The object of this invention is to maintain good insulation in transformers or
converters and avoid overheating when they are in operation.
It has before frequently been proposed to maintain good insulation in converters
by immersing them in heavy paraffin oils.
It has also been proposed to form the vessels containing the oil with wings or
projections standing out from them to expose greater surface to the air so as to
keep the vessels cool. As however the oil came only into contact with the exterior
of the converter it had but little effect in cooling it on the exterior-and again the
oil coming only into contact with the interior of the oil containing vessel the passage
of heat from the oil to the sides of the vessel was slow.
According to my invention I make the transformer with open spaces between the
primary and secondary coils and between the coils and surrounding iron. I place
such a converter within a vessel containing heavy oil so that the spaces are in an
upright position in order that the oil as it becomes heated in such spaces may rise
up and circulate freely through them.
In connection with the oil containing vessel I use cooling coils or tanks through
which the oil may be made to circulate either by natural flow on becoming heated or
artificially by pumping or forcing appliances.
The oil containing vessel may conveniently have a pipe rising up from it at the
top and then descending in a coil which may surround the exterior of the vessel and
pass back into the vessel at the bottom.
The vessel containing the transformer or the cooling coils or tanks may either be
allowed to cool by the surface they expose to the atmosphere or they may be cooled.
by a flow or circulation of water through pipes or passages or a flow of water over
the exterior of the cooling pipes or passages.
When a flow of water is used it may be controlled electrically so that water is
turned on when a certain amount of current is passing or by a thermostat arrange-
ment so as either by rise of load or temperature or by the movement of automatic
switches used for putting the converter in or out of action to turn the water on
and off.
When several transformers are used each transformer may be enclosed in a
separate oil containing vessel and each of the several vessels be connected by flow
and return pipes with cooling tanks or coils and the circulation maintained by natural
flow or artificially.
The transformers I usually form with two secondary coils one on the inside and
the other on the outside of the primary coil-the open vertical spaces between the
coils may be produced by winding rope upwards and downwards spirally around the
primary coil with open spaces between the several turns of the winding and then
placing the secondary coils inside and outside of the bound round primary-or the
two secondary coils might be spirally wound with rope and not the primary. Or in
place of winding the coils spirally with rope they may be wound with numerous
superposed spiral windings of narrow slips of paper or tape-or they may be bound
around in concentric rings of the desired thickness and at distances apart from one
another each ring formed by winding paper or tape around the coils in successive

page_text: layers until the desired thickness has been obtained. The windings may be either
around the primary or the two secondary or around all-in the latter case the
windings around the primary would be arranged to come intermediate of the
windings around the two secondary.
Preferably the windings are formed around the coils before they are placed one
within the other but they might be formed afterwards if desired.
Where the outer iron winding by which the coils are surrounded passes across
above the top and below the bottom of the primary and secondary coils a space is
maintained between the coils and the iron windings. This may be maintained by
ebonite distance pieces.
These distance pieces may be grooved on the outer side for the cords or windings
which surround the coils to lie in-so that the distance pieces would in this case be
bound to the coils by the windings. Or in place of using windings to keep spaces
between the coils and between the coils and iron windings the spaces might be kept
open by vertical ebonite distance strips at distances apart and these strips at the top
and bottom might lie in notches in the horizontal ebonite distance pieces which are
above and below the tops of the coils.
Dated this 20th day of June 1801
CARPMAEL & Co.,
Agents for the Applicant.
Improvements in connection with the Construction and Working of
Transformers or Converters.
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 :-
The object of this invention is to maintain good insulation in transformers or
converters and avoid overheating when they are in operation.
It has before frequently been proposed to maintain good insulation in converters
by immersing them in heavy paraffin oils.
It has also been proposed to form the vessels containing the oil with wings or
projections standing out from them to expose greater surface to the air so as to keep
the vessels cool. As however the oil came only into contact with the exterior of the
converter it had but little effect in cooling it on the exterior-and again the oil
coming only into contact with the interior of the oil containing vessel the passage
of heat from the oil to the sides of the vessel was slow.
According to my invention I make the transformer with open spaces between the
primary and secondary coils and between the coils and surrounding iron and I place
such a converter within a vessel containing heavy oil so that the spaces are in an
upright position in order that the oil as it becomes heated in such spaces may rise
up and circulate freely through them.
Figure 1 is a side elevation, Figure 2 an elevation partly in section and-Figure 3
a horizontal section of an oil containing vessel having within it a converter formed
in the manner above described with vertical spaces or channels between the coils
and between the coils and surrounding iron.
In some cases I use in connection with the oil containing vessel cooling coils or
tanks through which the oil may be made to circulate either by natural flow on
becoming heated or artificially by pumping or forcing appliances.
The oil containing vessel may conveniently have a pipe rising up from it at the
top and then descending in a coil which may surround the exterior of the vessel and
pass back into the vessel at the bottom.
The vessel containing the transformer or the cooling coils or tanks may either be
allowed to cool by the surface they expose to the atmosphere or they may be cooled

page_text: by a flow or circulation of water through pipes or passages or a flow of water over
the exterior of the cooling pipes or passages.
When a flow of water is used it may be controlled electrically so that water is
turned on when a certain amount of current is passing or by a thermostat arrange-
ment so as either by rise of load or temperature or by the movement of automatic
switches used for putting the converter in or out of action to turn the water on
and off..
When several transformers are used each transformer may be enclosed in a
separate oil containing vessel and each of the several vessels be connected by flow
and return pipes with cooling tanks or coils and the circulation maintained by
natural flow or artificially.
A diagram view of an arrangement in which the oil in the tank is cooled by a coil
In this figure
of pipe through which water is caused to flow is shewn at Figure 4.
A A are converters in vessels B B from the top of each of which a pipe rises to a
pipe C which opens into the top of a tank D. E is a pipe passing from the bottom
of the tank and E¹ branches from the pipe E to the bottom of each of the vessels B.
F is a coil of pipe within the tank through which water is caused to flow whenever
required.
The transformers I usually form with two secondary coils one on the inside and
the other on the outside of the primary coil such a converter is shewn in section in
Figure 3. G is the primary coil. H H are secondary coils and I the iron winding―
the open vertical spaces between the coils may be produced by winding a rope K
upwards and downwards spirally around the primary coil with open spaces between
the several turns of the winding as shewn in side elevation in Figure 5 and then
placing the secondary coils inside and outside of the bound round primary. Similarly
the vertical spaces between the coils and the iron winding may be produced by
winding another rope L spirally around all three coils as shewn in Figures 2
and 3.
Or the two secondary coils might be spirally wound with rope and not the
primary. Or in place of winding the coils spirally with rope they may be wound
with numerous superposed spiral windings of narrow slips of paper or tape-or they
may be bound around in concentric rings of the desired thickness and at distances
apart from one another each ring formed by winding paper or tape around the coils
in successive layers until the desired thickness has been obtained. The windings
may be either around the primary or the two secondary or around all-in the latter
case the windings around the primary would be arranged to come intermediate of
the windings around the two secondary.
Preferably the windings are formed around the coils before they are placed one
within the other but they might be formed afterwards if desired.
Where the outer iron winding by which the coils are surrounded passes across
above the top and below the bottom of the primary and secondary coils I further
maintain the space between the coils and the iron windings by ebonite distance
pieces M as shewn in the vertical section Figure 6. In this section the parts are
marked with the same letters of reference as in Figures 1, 2 and 3.
These distance pieces may be grooved on the outer side for the cords or windings
which surround the coils to lie in as shewn so that the distance pieces would in this
case be bound to the coils by the windings. Or in place of using windings to keep
spaces between the coils and between the coils and iron windings the spaces might
be kept open as shewn at Figures 7 and 8 by vertical ebonite distance strips at
distances apart and these strips at the top and bottom might lie in notches in the
horizontal ebonite distance pieces M which are above and below the tops of the
coils.
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
ton and hattam hatwann the primary

page_text: and secondary coils and between the coils and surrounding iron kept cool and
insulated by being immersed in a vessel filled with insulating liquid.
2. A converter kept cool and insulated by being placed in a tank through which
insulating liquid is caused to circulate either by natural flow on becoming heated or
artificially by pumping or forcing appliances.
3. A converter kept cool and insulated by being placed in a tank filled with
insulating liquid kept cool either by the liquid in the tank being made to circulate
through pipes or passages exposed to the atmosphere or to a flow of water or by
pipes or passages immersed in the liquid in the tank and cooling water made to
circulate through them.
4. Controlling the flow of cooling water electrically or by a thermostat so that
water is turned on when a certain amount of current is passing or when the
insulating liquid becomes heated beyond a certain point.
5. A converter with open spaces between the primary and secondary coils formed
by winding rope upwards and downwards spirally around one or more of the coils
substantially as described.
6. A converter with open spaces between the primary and secondary coils formed
by winding tapes or strips of paper or like narrow fabric in numerous superposed
spiral windings around one or more of the coils.
7. A converter with open spaces between the primary and secondary coils formed
by one or more of the coils being surrounded by a number of narrow parallel rings
each formed of rope or by winding round tapes or strips of paper or like narrow
fabric in successive layers until rings of the desired thickness are obtained.
8. Placing distance pieces of ebonite or like insulating material above the top
and below the bottom of the coils with grooves in them for the ropes or windings of
fabric to lie in substantially as described.
9. A. converter with spaces between the primary and secondary coils kept open
by vertical distance strips of ebonite or like insulating material which at top and
bottom lie in notches in other horizontal distance pieces of insulating material which
are above and below the tops of the coils.
Dated this 21st day of March 1892
S. Z. DE FERRANTI.