Electrical Energy by Induction.
Year: 1886

page_text: Date of Application, 23rd Aug., 1886.
Complete Left, 21st May, 1887.
Complete Accepted, 28th June, 1887
DEE
Electrical Energy by Induction.
WILLIAM LOWRIE of 117 Bishopsgate Street City of London Engineer and
CHARLES JAMES HALL of 1 Portland Road Finsbury Park County of Middlesex
Electrician do hereby declare the nature of this invention to be as follows:-
We form 2 cores of thin iron plates each iron plate being separately insulated from
the rest to prevent foucault currents. On each of these cores a primary and secondary
coil is wound part of the core projecting beyond the coils at both ends.
The coils are then placed side by side, and the plates of the projecting cores are
turned over alternately, each pair of plates forming a closed magnetic circuit insulated
from the rest.
The whole of the plates are then clamped tightly together at both ends to ensure
good magnetic contacts.
Any number, of these couples may be employed and their coils connected in series
or divided into sections and connected parallel to suit the conversion required.
The iron cores can be made of such dimensions that the required length of wire
can be wound thercon two deep one layer forming the primary and the other the
secondary coil or it may be wound one deep so that the convolutions are alternately
primary and secondary.
Thus all the wire being in such close proximity to the iron great efficiency is
obtained and the wires with the greatest difference of potential are the farthest apart
this being a great advantage where high tension is employed large heat radiating
surface is also obtained.
Dated this 02nd day of & nonet 1886
WILLIAM LOWRIE.
CHARLES JAMES HALL.

page_text: Electrical Energy by induction.
We, WILLIAM LOWRIE of No. 117 Bishopsgate Street, City of London, Engineer,
and CHARLES JAMES HALL of No. 1. Portland Road, Finsbury Park, in the County of
Middlesex, Electrician, do hereby declare the nature of this invention and in what
manner the same is to bo performed, to be particularly described and ascertained in
and by the following statement:-
Our invention relates to the conversion of electrical energy from one state or
condition of potential to another by induction, according to the researches and
discoveries of Faraday. The invention consists in the construction of the secondary
generators or induction apparatus employed in the process of conversion.
Our apparatus is constructed in the following manner. We form two cores of thin
soft iron plates, of square or rectangular form. These are built up of the several
plates, which are insulated from each other to avoid the formation of wasteful Foucault
currents. On the central portion of each of these cores we wind, or mount, a primary
coil, and a secondary coil, of insulated conductor; leaving portions of the core
projecting outward at each end. The two cores, with their coils, are mounted parallel
to each other at a short distance apart; and the several projecting plates are alternately
bent over a distance block at each end, and lapped over each other so that each pair
of plates forms an oblong ring and closed magnetic circuit; insulated from the rest.
To ensure good magnetic contacts, the whole of the lapped plates are tightly clamped
together by bolts, nuts, and plates; although other means of fastening them together
may be adopted.
These two cores with their coils, thus connected, may be regarded as unit couples:
any number of them may be employed according to the size of the apparatus required,
the kind of service, the size of plates or coils adopted, the position occupied, or
other practical considerations; and their coils may be connected in series or divided
into sections and connected in parallel or otherwise, to suit the kind of conversion
desired.
The plates which are used to make up the iron cores can be made of such dimensions,
either square or rectangular, that the required length of wire may be wound thereon
in two layers. But if more than two layers are employed, we prefer to have as few
as possible. When two layers are used, one layer would form the primary coil, and
the other the secondary coil. It is immaterial which coil is wound upon the coro first,
but either the primary or the secondary coil must be superimposed upon the other.
Where more than two layers are used the primary and the secondary coils may bo
wound in alternato superposed layers, but it is more convenient to finish the winding
of the first coil before beginning to wind the second. The coils are of double covered
cotton wire or insulated copper tape; but it will be understood that other methods of
insulation, or forms of conductor may be used. Each layer and coil must be well
insulated, and the ends of the coils are brought to the exterior and suitably connected.
Reference is made to the annexed drawings in which Fig. 1 is a plan, one half in
horizontal section along the line of Y-Z in Fig. 2, which represents a vertical section.
Fig. 3 is a transverse section of our apparatus.

page_text: Fig. 4 indicates the manner in which the core plates a are placed within clamps b, b,
suspended within or between lathe centres c, c, in order to wind the coils d. Before
placing the core plates a in the clamps, the edges of the plates are stiffened by wooden
strips e, e, on each side of the plates. The central part of the wood strips is rounded
to make the bend of the wire easy over the edge of the plates; and the strips also serve
to keep the plates in position and to stiffen the coils when completed. The clamps are
screwed to the wood strips at the ends, and after the coils have been wound, the wood
strips are sawn through at the points marked A, A, and B, B; thus leaving in position
only those portions of the strips held by the coils.
Fig. 5 is a cross section of the core plates a which are placed one over the other,
insulated from each other, and secured upon their edges by the strip of wood or other
insulating material just described. This figure shows the strips e with the clamp 6 in
position ready for the winding of the coils as before stated. In Fig. 6 the same
arrangement of core plates is shown, but with the exception that the two outer plates
are wider and are turned over the edges of the others for stiffening purposes, and the
wood strips are dispensed with. It will be seen that other plans of a like nature may
be adopted to produce the same result.
The several plates are insulated from each other in any convenient manner, but wo,
prefer the following method. One side of each plate is coated throughout with a
solution of shellac or other suitable substance, and upon this we place a layer of some
open work fabric such as that known as book muslin, and cause it to adhere by the
application of heat and pressure. The plates are arranged in regular order, one above
another; each insulated side of a plate being placed next to the uncoated side of the
plate adjoining until the requisite number is attained to form each core. The insulated
or stiffening strips are now placed upon each side or edge of the plates, the clamps
placed in position, and the core is now wound as before stated.
Two straight cores, having thus been wound with their coils, are placed in position
ready to be joined together. In Fig. 2, a, a, represent the cores, d¹ the primary coils,
and, the secondary coils. At the ends of the coils, and between the cores, aro placed
distance blocks f, and, beginning with the inner ones, each plate of each core is bent
over the distance block alternately; so that the projecting ends lap over one upon
another, the uncoated side.of one plate being in metallic contact with the uncoated side
of its fellow plate, as shown by the diagram Fig. 7. This diagram further shows by
dotted lines the double layers of insulation between the plates where the coated sides
como in contact with each other; and as the diagram is drawn to show one half, it
will be seen that when each pair of plates at each end of the cores are brought
together, an elongated ring, or ring with flattened sides is formed, composed of a
series or system of independent magnetic circuits, in which lines of force are free to
circulate without forming poles.
When the plates are thus lapped over to form an elongated ring core, insulated
clamping bolts, plates, and nuts, g, g, are used to ensure good magnetic contact with
stability; the clamping devices g being attached to the distance blocks f, standards or
supports h, and to side frames i, of wood, or some other suitable insulating material.
Upon these side frames are mounted suitable terminals i, j, and k, k, to which the
circuit connections are attached.
Fig. 8 is a diagram of an arrangement of three coils, showing by a thick line their
cores and the manner in which their ends may be clamped together, or otherwise con-
nected. Fig. 9 is a similar diagram of four coils, and either of these arrangements may
be carried out according to our invention, and the coils placed either vertically or
horizontally. But we prefer to make our apparatus in the form of a unit pair or any
multiple thereof; the axis of the coils being in either a horizontal or a vertical plane,
as may be most convenient. Fig. 11 indicates a vertical arrangement of two unit
pairs, the cores being bent at the top and bottom and clamped together in the
form of a cross. In this form, the clamping devices extend diagonally across the
angles, and bolt heads or feet at the bottom, serve as a base to stand upon.
Fig. 12 is a plan of a secondary generator or induction apparatus of three unit
pairs, which embodies our invention. Fig. 13 is a longitudinal section along the line

page_text: A-B and Fig. 14 a transverse section on the line C-D of Fig. 12. The principal
parts insulated are shown by heavy black lines in Figs. 13 and 14; and it will be
understood that the plates, bolts, and nuts of the clamping devices g, or any other
parts requiring the same, will be suitably insulated. Any number of pairs may be
combined in the same apparatus, and any one of the group can be cut out while the
apparatus is in action without detriment to the remainder. The coils employed are
suitably connected to suit the kind of conversion or change of potential required.
In order that this may be clear, we give an example of an apparatus consisting of
three unit pairs or complete magnetic circuits, in which six sets of double coils are
employed. This apparatus is shown in Figs. 12, 13, and 14; each of the six primary
coils is wound with copper wire of No. 14 Birmingham wire gauge in three layers,
and the whole of the eighteen layers of wire is connected in series: Each of the six
secondary coils also consists of three layers of the same size of conductor, and is
superimposed upon its corresponding primary coil; and the whole of the eighteen
layers of secondary wire is connected in parallel. By means of this apparatus the
potential of the primary or exciting current, is reduced from 1,800 volts to 100 volts.
The conductors used may be the usual double covered wire, but copper tape, suitably
insulated, may be used instead. If carefully wound and insulated between the layers
and adjoining strands, the copper tape may be bare.
An important feature of our invention consists in the shape of the plates which
form the core. By making the plates square or-rectangular in form, and regulating
their number or aggregate thickness, we are enabled to exactly provide for any length
of conductor required without undue weight of core; and we also reduce to a
minimum the length, and therefore the resistance of the magnetic circuit. It will be
observed that each core, or assemblage of completed magnetic circuits, has two or
more flat or straight sides, as exemplified in the Figures 8 and 9. Other geometrical
forms may also be employed. In Fig. 11 the complete magnetic circuit takes tho
form of two elongated rings or links, the respective planes of which are arranged at
right angles to each other, but magnetically connected together at the centre of their
ends. This form is therefore that of two unit pairs combined, and it being more
convenient to describe and claim the same in this sense, it is to be understood that our
improved method of forming closed magnetic circuits consists of an assemblage of
thin iron plates, of square or rectangular shape, originally straight, bent or otherwise
connected at tho onds by clamping devices and distance blocks, and having two or
more straight sides upon which the primary and secondary coils are mounted, and
through which the iron core passes.
The unit pair is therefore, in its simplest form, an elongated or flat sided ring;
each of the opposite flat sides having the double coils wound thereon, and the ends of
the core plates being closed or connected together as close to the coils as is practicable
in order to reduce the length, weight, and resistance of the magnetic core. In Fig. 10,
coils d, d, are mounted upon a magnetic core a of an elongated ring shape, but
surrounding the outer part of the coils, and placed within, are two other magnetic
cores marked a¹ and a² respectively, which we find are practically useless unless they
are all magnetically connected together at a as shown in the diagram. By our
method of forming the core we cause the whole of the magnetic currents circulating
through the magnetic circuit to pass through the interior of the coils; we reduce the
length of the said circuit to a minimum; we lessen the magnetic resistance and cost
of construction; and obtain generally a better result from the apparatus than has
heretofore been known.
Having now particularly described and ascertained the nature of our said
Invention, and in what manner the same is to be performed, we declare that what
wo claim is :
1. A secondary generator or induction apparatus, constructed substantially in the
manner shown or described, and employed in the conversion of electrical from one
state or condition of potential to another.

page_text: from each other, and stiffened upon the edges to enable the winding thereon in a
lathe of one or more coils of conductor, substantially as described.
3. In a secondary generator, the method of forming complete magnetic circuits by
the combination of two or more laminated iron cores, a part of each core having
superposed straight coils wound or placed thereon; substantially as described.
4. Two or more laminated magnetic cores joined to form a number of independent
closed magnetic circuits, combined with straight wound superposed coils, mounted
upon and surrounding a portion of each core before joining; substantially as
described.
5. In a secondary generator, the method of overlapping the ends of the core plates
and clamping the same together to ensure good contact between the corresponding
plates of two or more cores, so as to form a number of independent complete magnetic
circuits, substantially as described.
6. Two or more laminated iron cores having superposed coils wound thereon,
combined with distance pieces or blocks adapted to receive the end portions of the
cores, and clamping devices to clamp the blocks and cores together in their relative
positions; substantially as and for the purpose described.
7. The method of arranging two or more laminated cores, (having primary and
secondary coils wound on each core), upon a frame or frames adapted to receive the
said cores, and afterwards clamping the several plates together to form closed
magnetic circuits by means of bolts, nuts and plates, or similar devices; substantially
as described.
8. A flat sided ring core or continuous magnetic circuit, built up of insulated thin
plates of square or rectangular shape, the ends being clamped together, and having
two or more straight portions upon the said core for the reception of coils;
substantially as and for the purpose described.
9. A secondary generator or induction apparatus comprising two or more sets of
primary and secondary coils, surrounding straight portions of an endloss or continuous
core of closed magnetic circuits, the said endless core being composed of two or more
sets of laminated plates clamped together at their junctions; substantially as
described.
10. In secondary generators or induction apparatus, combining any number of
unit pairs or systems of closed magnetic circuits with their coils into one apparatus,
and connecting the primary coils and the secondary coils thereof in parallel, so that
any one of the group could be cut out while in action without detriment to the
remainder; substantially as described.
11. In secondary generators or induction apparatus, combining any number of
unit pairs or systems of closed magnetic circuits into one apparatus, and connecting
the primary coils and the secondary coils thereof to suit any electrical conversion
required; substantially as and for the purpose described.
12. In a secondary generator or induction apparatus, the several forms or parts
shown by the accompanying drawings; substantially as and for the purpose
described.
FAIRFAX & WETTER,
433, Strand, London,
Agents for the Applicants.