Year: 1887

page_text: This Specification was, upon the 15th day of December 1888, Amended under.
Sections 18 to 21 of the Patents, Designs, and Trade Marks Act, 1883.
I, JOHN GRICE STATTER, of Alliance Engineering Works, West Drayton,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to improvements in electrical transformers whereby certain
advantages are obtained. The electric circuits necessary in this class of mechanism
consist of two independent electric circuits insulated from each other and each such
circuit is formed of one or more coils. The action of this class of electrical apparatus
is well known.
In the following description it is assumed that there are only two coils, one
primary and one secondary.
In order to obtain the greatest inductive effect of the primary upon the secondary
coil it is necessary to so construct arrange and dispose the magnetic material with
reference to the said coils that the greatest possible number of lines of force may be
generated by the primary coil and concentrated upon the secondary coil, care being
at the same time taken to prevent the formation of Foucault or eddy currents which
would interfere with such inductive effect.
In carrying my invention into effect, I endeavour to obtain the greatest possible
inductive effect as aforesaid; and for this purpose I proceed as follows:-
1 stamp or cut out of thin sheet iron, preferably Swedish charcoal iron, pieces of
a shape somewhat resembling the letter E, save that the letter is turned round
through an angle of 90 degrees, so that the part which corresponds with the down
stroke of the letter is placed horizontally, and the parts which correspond with
the horizontal lines project vertically upwards. Thus each piece consists of a strip,
hereinafter called the base, having three projections standing up from it vertically,
one is at each end of the base and about equal to it in width, and one in the
middle and of about twice the width of the said base. I take two such pieces,
hereinafter referred to as sheets, and insulate or varnish one side of each. I place
one on the other with their insulated sides together, so that they shall exactly
coincide with one another, and press them together so that they stick fast, and so
constitute what I may for the purposes of this specification term a compound plate.
077

page_text: I now make two coils, one primary and one secondary, rectangular in section and in
shape of winding, and of such a size that when placed one on the top of the other
and bound together with insulating tape or the like either side of the compound
coil thus formed shall form a rectangle which shall just fill up one space between
a side and the middle projection of each of the above mentioned stampings: and
the coils are wound of such a size that all the middle projections when built up
shall just fill up the space between the two sides of the compound coil. For
convenience of description distinguish those parts of the coil which lie between
the middle and side projections of the plates by the term "sides," and those parts
which connect the said sides and which stand out from the plates when the latter are
built up as
ends." Supposing the compound coil to be held standing vertically
upon end in front of a workman constructing the transformer, with his right hand he
places a plate forcing the middle projection between the sides of the coil; then with
his left hand he forces in another plate from the opposite direction and presses it upon
the first plate: next with his right hand he places another plate from the same
direction as the first, pressing this upon the last plate, and so on alternately inserting
plates from either direction, so that the projections of the plates overlap, and
their uninsulated surfaces are in contact, and so form a good magnetic contact of
large surface.
If, as before mentioned, the depth of the sides of the compound coil is equal to the
length of the projections of the plate, the overlapping will only extend to the edges of
the coil, and there will be air spaces between the bases of each plate. These spaces I
may fill
up by pieces of soft iron sheet cut to fit them or by soft iron wire.
I can also construct a compound plate from these sheets in the following manner.
I take a single sheet, shaped as hereinbefore described, and insulate it upon one side
only. I make the projections the same depth as the sides of the compound coil, and
machine off the projections on the uninsulated side taper from full thickness as they
leave the base to almost nothing at the tip. I now place these in the coil as herein-
before described, the machined sides being in contact with each other. In this
manner good magnetic contact is attained with good insulation in the direction
desired; but no spaces are left between the bases in this case. It will be understood
that when desired I may insulate or varnish both surfaces of the sheets, afterwards
machining off such parts as may be desired in order to insure good magnetic
contact.
The plates are clamped together by pressure: and it will be seen that the compound
coil is entirely covered by the iron except at the ends. To facilitate radiation of the
heat produced in the coils during action plates or sheets of larger dimensions may
when desired be inserted at intervals: and the transformer may be immersed in an
insulation, and sealed up in a tight case.
I may when desired insulate only each alternate sheet or compound plate of which
the transformer is built up.
D711
J. G. LORRAIN,
Norfolk House, Norfolk Street,
London, W.C.
Agent for Applicant

page_text: I, JOHN GRICE STATTER, of Alliance Engineering Works, West Drayton, 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
My invention relates to improvements in electrical transformers whereby certain
advantages are obtained. The electric circuits necessary in this class of mechanism
consists of two independent electric circuits insulated from each other; and each such
circuit is formed of one or more coils. The action of this class of electrical apparatus
is well known.
In the following description it is assumed that there are only two coils, one primary
and one secondary.
In order to obtain the greatest inductive effect of the primary upon the secondary
coil, it is necessary to so construct, arrange and dispose the magnetic material with
reference to the said coils, that the greatest possible number of lines of force may
be generated by the primary coil, and consentrated upon the secondary coil, care being
at the same time taken to prevent the formation of Foucault or eddy currents which
would interfere with such inductive effect.
In carrying my invention into effect I endeavour to obtain the greatest possible.
inductive effect as aforesaid; and for this purpose I proceed as follows:-
I stamp or cut out of thin sheet iron, preferably Swedish charcoal iron, pieces of a
shape somewhat resembling the letter E. Each such piece consists of a base having
One, hereinafter called an "external projec-
three projections springing from it.
tion," is at each end of the base and about equal to it in width; and one, hereinafter
called the "central projection," is in the middle, and is of about twice the width of
the said base. The surfaces of these plates I varnish or coat with an insulating
material. Such a plate is shown in figure 1, in which A is the base, B the central
projection, and CC the external projections. The central projection is of about twice
the width of the external projections, so that what I may for the purposes of this
specification term its magnetic capacity may equal that of the two external projections.
Figure 2 shews a plate differing from the last only in that instead of being of
The configuration of the
rectangular configuration it is of circular configuration.
plates is capable of further modifications when desired. For example instead of being
rectangular, as in Figure 1, or circular, as in Figure 2, they might be square or

page_text: eliptical. Such external configuration of the plate is in most cases determined by the
form of the containing case in which the transformer is to be placed.
I now make two coils, one primary and one secondary, rectangular or nearly so in
section and in shape of winding, and of such a size that, when placed one on the top
of the other, and bound together with insulating tape or the like, either side of the
compound coil thus formed shall form a rectangle, which shall just fill up one space
between an external projection and the central projection of each of the above
mentioned plates; and the coils are wound of such a size that all the central projections
when built up shall just fill up the space between the two sides of the compound coil.
For convenience of description I distinguish those parts of the coil which lie between
the central and the external projections of the plates, by the term "sides," and those
parts which connect the said sides, and which stand out from the plates when the
latter are built
up as "ends."
To construct the transformer let us suppose the compound coil to be held standing
vertically upon end in front of the workman. With his right hand he places a plate
in position, inserting the central projection between the sides of the coil."
Then with
his left hand he forces in another plate from the opposite direction, and presses it upon
the first plate. Next with his right hand he places another plate from the same
direction as the first, pressing this upon the last plate, and so on, alternately inserting
plates from either direction, so that the projections of the plates overlap each other.
Figures 3 and 3 A shew sections, taken at right angles to one another, of a trans-
former so built up, the primary coil being shown at P and the secondary coil at S,
whilst the parts of the plates have the same lettering as in Figure 1. It will of course
be understood however that these are not the necessary relative positions of the primary
and secondary coils, as the relative positions shewn in the figure might without dis-
advantage be reversed. The plates are pressed together and retained in position by
clamps, or any other suitable known devices, such as bolts as shewn in figures 3 and 3 A.
It will be seen that the compound coil is entirely surrounded by iron except at the
ends.
Figure 4 shows a form of plate which differs from that shewn in figure 1 only in
that a slot is cut in the middle projection for the purpose of ventilation.
If, as before mentioned when referring to the compound coil, the depth of the
sides of the compound coil is equal to the length of the projections of the plate, then
the overlapping of the plates will only extend to the edges of the coil; and there
will be air spaces between the bases of each plate. These spaces
pieces of soft iron. These pieces of iron may either be separate pieces of sheet iron,
may fill up by
cut to fit the spaces, or they may be integral with the plates themselves, forming
parts or wings of the projections. When this latter plan is adopted, namely that
of having these pieces integral with the E shaped plates, I stamp out or cut the
whole plate from one sheet of soft iron as represented in figures 6 and 7 where it
will be seen that the plates are divided as shewn by the lines 0 0. In order to place
these plates in position, after the manner hereinbefore described, I find it necessary to
bend aside the winged parts marked F F F F in figures 6 and 7 when passing the
projections through or by the side of the coils, and afterwards to bend these wings
back into their original positions, that is into the same plane as the rest of the plate.-
To aid in such bending aside as I have just mentioned I find it convenient to make
small cuts as shewn at G G G G in figures 6 and 7; but if the plates be very thin
and flexible such cuts may be dispensed with. In figures 6 A and 7.A I shew the
plates illustrated in figures 6 and 7 respectively with the wings bent aside for
the purpose of enabling the plates to be placed in position when building up the
transformer.
I have hereinbefore stated that in constructing my transformer the plates are
alternately placed in position from either side-that is alternately in opposite
directions. This is not however necessary in all cases in order to obtain good results.
For example alternate plates of the forms shewn in figures 6 and 7 respectively
placed all from the same direction will make a good transformer.

page_text: I have hereinbefore stated that I insulate the plates of which my transformer is
built up by varnishing the surfaces, or coating them with an insulating material.
Another method which I sometimes employ, and which serves the same purpose, is to
interpose thin sheets of paper, or other suitable insulating material, between the
plates.
<<
Instead of employing what I may term "simple plates," such as hereinbefore
described, I sometimes employ what I may for the purposes of this specification term
compound plates." To form a compound plate I take two simple plates, as herein-
before described, and insulate or varnish one side of each. I then place one on the
other with their insulated sides together, so that they shall exactly coincide with one
another, and press them together so that they stick fast, and so constitute the
compound plate. Figure 8 is an end view of such a compound plate (exagerated in
thickness for the purpose of demonstration) the insulated surface being shewn by
dotted lines.
I can also construct a compound plate from simple plates in the following manner.
I take a simple plate, shaped as herein before described, and insulate it upon one side
only. I make the projections the same depth as the sides of the compound coil, and
machine off part of the metal on the uninsulated surface of the projections so as to
taper their thickness from full thickness as they leave the base to almost nothing at
the tip. I now place these in the coil as herein before described, the machined sides
being in contact with each other. In this manner good magnetic contact is attained,
with good insulation in the direction desired, but no spaces are left between the bases
in this case. Figure 9 shews a number of such compound plates. It will be understood
that when desired I may insulate or varnish both surfaces of the sheets, afterwards
machining off such parts as may be desired in order to insure good magnetic contact.
I may when desired insulate only each alternate simple or compound plate of which
the transformer is built up.
In figure 4 I shew a method of ventilating the transformer by means of a ventilating
passage in the iron itself. I find it advantageous however to ventilate the coils also ;
and prefer to do this by separating the primary coil from the secondary coil by
means of an air space, the two coils being kept apart by rods or blocks of suitable
material. Such a method of ventilation is shown in figure 10. Another method of
ventilation which I sometimes employ is shewn in figure 11. In this case I prevent
both the primary and secondary coil from actually touching the E shaped plates of
iron by inserting between them and the iron plates, rods, blocks or other contrivances,
thus leaving a narrow air space between the coils and the plates. Figures 12 and 13
shew,, in vertical section and plan respectively, a convenient method of grouping
plates in a case or box to facilitate cooling. For the purpose of acting as radiators I
insert larger plates or groups of plates at intervals as shown at K K K in figure 12;
and when I insert the transformer into an iron case as shown in figure 12 these
radiators or larger plates project beyond the other plates on three sides only, and
extend to the walls of the case on these three sides, so that on the side on which they
do not project there is a space left between the transformer and the wall of the case.
By arranging these spaces alternately on opposite sides of the transformer, and pro-
viding suitable openings at the top and bottom of the case, the air is caused to circulate
as shown by the arrows in figures 12 and 13.
ૐ
Instead of a separate iron case, such as that shewn in figures 12 and 13, being used
for the transformers, such case might be constituted by part of a tubular iron lamp
post, or by an iron casing serving to contain the regulating mechanism of an arc
lamp. As arc lamps are at present constructed, however, this latter plan is not
always advantageous, inasmuch as the regulating mechanism is placed above the
carbons where there is not only more heat but where any superfluous weight is
objectionable.
I find it convenient to enclose my transformers in iron cases, provided with two
rectangular enclosed chambers for the primary and secondary leads to enter and
leave, and to contain the switch and fuse for the primary circuit.

page_text: I desire it to be understood that I do not lay any claim to the employment of simple
E shaped plates unless they be furnished with wings or be arranged in groups of different
size for the purpose of facilitating cooling. Nor do I lay any claim to the employment
of compound plates unless such be formed of simple plates machined of taper or be
arranged in groups of different size for the purpose of facilitating cooling.
6 Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is :-
1. The improvement in electrical transformers consisting in the employment of
simple E shaped plates substantially as set forth, and subject to the above disclaiming
clause.
2. The improvement in electrical transformers consisting in the employment of
compound plates substantially as set forth, and subject to the above disclaiming clause.
3. The respective improvements in electrical transformers consisting in the several
specific forms of plate shewn in figures 1, 2, 4, 6, 7, 8 and 9.
Dated this 1st day of December 1887.
For the Applicant,
J. G. LORRAIN, M.S.T.E., M. Inst. M.E.,
Norfolk House, Norfolk Street, London, W.C.,
Patent Agent.

page_text: Date of Application, 25th May, 1887
Complete Left, 2nd Dec., 1887
Complete Accepted, 27th Jan., 1888
I, JOHN GRICE STATTER, of Alliance Engineering Works, West Drayton,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to improvements in electrical transformers whereby certain
advantages are obtained. The electric circuits necessary in this class of mechanism
consist of two independent electric circuits insulated from each other and each such
circuit is formed of one or more coils. The action of this class of electrical apparatus
is well known.
In the following description it is assumed that there are only two coils, one
primary and one secondary.
In order to obtain the greatest inductive effect of the primary upon the secondary
coil it is necessary to so construct arrange and dispose the magnetic material with
reference to the said coils that the greatest possible number of lines of force may be
generated by the primary coil and concentrated upon the secondary coil, care being
at the same time taken to prevent the formation of Foucault or eddy currents which
would interfere with such inductive effect.
In carrying my invention into effect, I endeavour to obtain the greatest possible
inductive effect as aforesaid; and for this purpose I proceed as follows:-
I stamp or cut out of thin sheet iron, preferably Swedish charcoal iron, pieces of
a shape somewhat resembing the letter E, save that the letter is turned round
through an angle of 90 degrees, so that the part which corresponds with the down
stroke of the letter is placed horizontally, and the parts which correspond with
the horizontal lines project vertically upwards. Thus each piece consists of a strip,
hereinafter called the base, having three projections standing up from it vertically,
one is at each end of the base and about equal to it in width, and one in the
middle and of about twice the width of the said base. I take two such pieces,
hereinafter referred to as sheets, and insulate or varnish one side of each. I place
one on the other with their insulated sides together, so that they shall exactly
coincide with one another, and press them together so that they stick fast, and so
constitute what I may for the purposes of this specification term a compound plate.

page_text: I now make two coils, one primary and one secondary, rectangular in section and in
shape of winding, and of such a size that when placed one on the top of the other
and bound together with insulating tape or the like either side of the compound
coil thus formed shall form a rectangle which shall just fill up one space between
a side and the middle projection of each of the above mentioned stampings: and
the coils are wound of such a size that all the middle projections when built up
shall just fill up the space between the two sides of the compound coil. For
convenience of description I distinguish those parts of the coil which lie between
the middle and side projections of the plates by the term "sides," and those parts
which connect the said sides and which stand out from the plates when the latter are
built up as
"ends." Supposing the compound coil to be held standing vertically
upon end in front of a workman constructing the transformer, with his right hand he
places a plate forcing the middle projection between the sides of the coil; then with
his left hand he forces in another plate from the opposite direction and presses it upon
the first plate: next with his right hand he places another plate from the same
direction as the first, pressing this upon the last plate, and so on alternately inserting
plates from either direction, so that the projections of the plates overlap, and
their uninsulated surfaces are in contact, and so form a good magnetic contact of
large surface.
If, as before mentioned, the depth of the sides of the compound coil is equal to the
length of the projections of the plate, the overlapping will only extend to the edges of
the coil, and there will be air spaces between the bases of each plate. These spaces
may fill up by pieces of soft iron sheet cut to fit them or by soft iron wire.
I
I can also construct a compound plate from these sheets in the following manner.
I take a single sheet, shaped as herein before described, and insulate it upon one side
only. I make the projections the same depth as the sides of the compound coil, and
machine off the projections on the uninsulated side taper from full thickness as they
leave the base to almost nothing at the tip. I now place these in the coil as herein-
before described, the machined sides being in contact with each other. In this
manner good magnetic contact is attained with good insulation in the direction
desired; but no spaces are left between the bases in this case. It will be understood
that when desired I may insulate or varnish both surfaces of the sheets, afterwards
machining off such parts as may be desired in order to insure good magnetic
contact.
The plates are clamped together by pressure: and it will be seen that the compound
coil is entirely covered by the iron except at the ends. To facilitate radiation of the
heat produced in the coils during action plates or sheets of larger dimensions may
when desired be inserted at intervals: and the transformer may be immersed in an
insulation, and sealed up in a tight case.
I may when desired insulate only each alternate sheet or compound plate of which
the transformer is built up.
Dated the outh day of M. 1907
J. G. LORRAIN,
Norfolk House, Norfolk Street,
London, W.C.
Agent for Applicant

page_text: 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 :-
My invention relates to improvements in electrical transformers whereby certain
advantages are obtained. The electric circuits necessary in this class of mechanism
consist of two independent electric circuits insulated from each other; and each such
circuit is formed of one or more coils. The action of this class of electrical apparatus
is well known.
In the following description it is assumed that there are only two coils, one primary
and one secondary.
In order to obtain the greatest inductive effect of the primary upon the secondary
coil, it is necessary to so construct, arrange and dispose the magnetic material with
reference to the said coils, that the greatest possible number of lines of force may
be generated by the primary coil, and consentrated upon the secondary coil, care being
at the same time taken to prevent the formation of Foucault or eddy currents which
would interfere with such inductive effect.
In carrying my invention into effect I endeavour to obtain the greatest possible
inductive effect as aforesaid; and for this purpose I proceed as follows:-
I stamp or cut out of thin sheet iron, preferably Swedish charcoal iron, pieces of a
shape somewhat resembling the letter E. Each such piece consists of a base having
three projections springing from it. One, hereinafter called an "external projec-
tion," is at each end of the base and about equal to it in width; and one, hereinafter
called the "central projection," is in the middle, and is of about twice the width of
the said base. The surfaces of these plates I varnish or coat with an insulating
material. Such a plate is shewn in figure 1, in which A is the base, B the central
projection, and CC the external projections. The central projection is of about twice
the width of the external projections, so that what I may for the purposes of this
specification term its magnetic capacity may equal that of the two external projections.
Figures 2 shews a plate differing from the last only in that instead of being of
rectangular configuration it is of circular configuration. The configuration of the
plates is capable of further modifications when desired. For example instead of being
rectangular, as in Figure 1, or circular, as in Figure 2, they might be square or

page_text: епрысал. Such external configuration of the plate is in most cases determined by the
form of the containing case in which the transformer is to be placed.
I now make two coils, one primary and one secondary, rectangular or nearly so in
section and in shape of winding, and of such a size that, when placed one on the top
of the other, and bound together with insulating tape or the like, either side of the
compound coil thus formed shall form a rectangle, which shall just fill up one space
between an external projection and the central projection of each of the above
mentioned plates; and the coils are wound of such a size that all the central projections
when built up shall just fill up the space between the two sides of the compound coil.
For convenience of description I distinguish those parts of the coil which lie between
the central and the external projections of the plates, by the term "sides," and those
parts which connect the said sides, and which stand out from the plates when the
latter are built up, as ends."
To construct the transformer let us suppose the compound coil to be held standing
vertically upon end in front of the workman. With his right hand he places a plate
in position, inserting the central projection between the sides of the coil. Then with
his left hand he forces in another plate from the opposite direction, and presses it upon
the first plate. Next with his right hand he places another plate from the same
direction as the first, pressing this upon the last plate, and so on, alternately inserting
plates from either direction, so that the projections of the plates overlap each other.
Figures 3 and 3 A shew sections, taken at right angles to one another, of a trans
former so built up, the primary coil being shewn at P and the secondary coil at S,
whilst the parts of the plates have the same lettering as in Figure 1. It will of course
be understood however that these are not the necessary relative positions of the primary
and secondary coils, as the relative positions shewn in the figure might without dis-
advantage be reversed. The plates are pressed together and retained in position by
clamps, or any other suitable known devices, such as bolts as shewn in figures 3 and 3 A.
It will be seen that the compound coil is entirely surrounded by iron except at the
ends.
Figure 4 shows a form of plate which differs from that shewn in figure 1 only in
that a slot is cut in the middle projection for the purpose of ventilation.
If, as before mentioned when referring to the compound coil, the depth of the
sides of the compound coil is equal to the length of the projections of the plate, then
the overlapping of the plates will only extend to the edges of the coil; and there
will be air spaces between the bases of each plate. These spaces I may fill
up by
pieces of soft iron. These pieces of iron may either be separate pieces of sheet iron,
cut to fit the spaces, or they may be integral with the plates themselves, forming
parts or wings of the projections. When this latter plan is adopted, namely that
of having these pieces integral with the E shaped plates, I stamp out or cut the
whole plate from one sheet of soft iron as represented in figures 6 and 7 where it
will be seen that the plates are divided as shewn by the lines 00. In order to place
these plates in position, after the manner hereinbefore described, I find it necessary to
bend aside the winged parts marked F F F F in figures 6 and 7 when passing the
projections through or by the side of the coils, and afterwards to bend these wings
back into their original positions, that is into the same plane as the rest of the plate.
To aid in such bending aside as I have just mentioned 1 find it convenient to make
small cuts as shewn at G G G G in figures 6 and 7; but if the plates be very thin
and flexible such cuts may be dispensed with. In figures 6 A and 7 A I shew the
plates illustrated in figures 6 and 7 respectively with the wings bent aside for
the purpose of enabling the plates to be placed in position when building up the
transformer.
I have herein before stated that in constructing my transformer the plates are
alternately placed in position from either side-that is alternately in opposite
directions. This is not however necessary in all cases in order to obtain good results.
For example alternate plates of the forms shewn in figures 6 and 7 respectively
placed all from the same direction will make a good transformer.

page_text: I have herein before stated that I insulate the plates of which my transformer is
built up by varnishing the surfaces, or coating them with an insulating material.
Another method which I sometimes employ, and which serves the same purpose, is to
interpose thin sheets of paper, or other suitable insulating material, between the
plates.
66
Instead of employing what I may term "simple plates," such as hereinbefore
described, 1 sometimes employ what I may for the purposes of this specification term
compound plates." To form a compound plate I take two simple plates, as herein-
before described, and insulate or varnish one side of each. I then place one on the
other with their insulated side together, so that they shall exactly coincide with one
another, and press them together so that they stick fast, and so constitute the
compound plate. Figure 8 is an end view of such a compound plate (exagerated in
thickness for the purpose of demonstration) the insulated surface being shewn by
dotted lines.
I can also construct a compound plate from simple plates in the following manner.
I take a simple plate, shaped as herein before described, and insulate it upon one side
only. I make the projections the same depth as the sides of the compound coil, and
machine off part of the metal on the uninsulated surface of the projections so as to
taper their thickness from full thickness as they leave the base to almost nothing at
the tip. 1 now place these in the coil as hereinbefore described, the machined sides
being in contact with each other. In this manner good magnetic contact is attained,
with good insulation in the direction desired, but no spaces are left between the bases
in this case. Figure 9 shows a number of such compound plates. It will be understood
that when desired I may insulate or varnish both surfaces of the sheets, afterwards
machining off such parts as may be desired in order to insure good magnetic contact.
I may when desired insulate only each alternate simple or compound plate of which
the transformer is built up.
In figure 4 shew a method of ventilating the transformer by means of a ventilating
passage in the iron itself. I find it advantageous however to ventilate the coils also;
and I prefer to do this by separating the primary coil from the secondary coil by
means of an air space, the two coils being kept apart by rods or blocks of suitable
material. Such a method of ventilation is shewn in figure 10. Another method of
ventilation which I sometimes employ is shewn in figure 11. In this case I prevent
both the primary and secondary coil from actually touching the E shaped plates of
iron by inserting between them and the iron plates, rods, blocks or other contrivances,
thus leaving a narrow air space between the coils and the plates. Figures 12 and 13
shew, in vertical section and plan respectively, a convenient method of grouping
plates in a case or box to facilitate cooling. For the purpose of acting as radiators I
insert larger plates or groups of plates at intervals as shown at K K K in figure 12;
and when I insert the transformer into an iron case as shown in figure 12 these
radiators or larger plates project beyond the other plates on three sides only, and
extend to the walls of the case on these three sides, so that on the side on which they
do not project there is a space left between the transformer and the wall of the case.
By arranging these spaces alternately on opposite sides of the transformer, and pro-
viding suitable openings at the top and bottom of the case, the air is caused to circulate
as shewn by the arrows in figures 12 and 13.
Instead of a separate iron case, such as that shewn in figures 12 and 13, being used
for the transformers, such case might be constituted by part of a tubular iron lamp
post, or by an iron casing serving to contain the regulating mechanism of an arc
lamp. As are lamps are at present constructed, however, this latter plan is not
always advantageous, inasmuch as the regulating mechanism is placed above the
carbons where there is not only more heat but where any superfluous weight is
objectionable.
I find it convenient to enclose my transformers in iron cases, provided with two
rectangular enclosed chambers for the primary and secondary leads to enter and
leave, and to contain the switch and fuse for the primary circuit.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is:
-
1. The improvement in electrical transformers consisting in the employment of
simple E shaped plates substantially as set forth.
2. The improvement in electrical transformers consisting in the employment of
compound plates substantially as set forth.
3. The respective improvements in electrical transformers consisting in the several
specific forms of plate shewn in figures 1, 2, 4, 6, 7, 8 and 9.
Dated 11
10077
For the Applicant,
J. G. LORRAIN, M.S.T.E., M. Inst. M.E.,
Norfolk House, Norfolk Street, London, W.C.,
Patent Agent.