Improvements in Electro Magnets, and Method of Winding the same.
Year: 1895

page_text: Date of Application, 24th Sept., 1895-Accepted, 24th Sept., 1895
VOMI DELE SPECIFICATION.
[Communicated from abroad by HOWARD LACY, LOUIS F. JOHNSON, and
WALTER J. SLACKE, all of 66 Centre Square, in the City of Easton, in
the County of Northampton and State of Pennsylvania, United States of
America.]
Improvements in Electro Magnets, and Method of Winding
the same.
I, DUGALD CLERK, of 18 Southampton Buildings, Chancery Lane
London, W.C., 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 :-
The object of this invention is to produce an electro magnet which shall have a
magnetic field of greater extent and greater intensity than electro magnets of
corresponding size as now ordinarily constructed. The invention as herein
disclosed finds expression in certain features of construction and also in the method
of winding the magnet, all of which contribute in some degree to the general result
aimed at and are fully described hereinafter.
In the accompanying drawings-
Figure 1 is a plan view, partly in horizontal, central section, of an electric
magnet embodying the present improvements.
Figure 2 is an end elevation of the same, partly in vertical section.
Figures 3, 4 and 5, are diagrammatic views illustrating the method of winding.
Figure 6 is a plan view of one part or pole of the magnet, partly wound, also
illustrating the method of winding.
The core A of the magnet consists of a bundle of soft iron wires laid in parallelism
and held together in a substantially cylindrical form. At each end of the bundle
and firmly attached thereto is a soft iron, annular disc B which for convenience and
to indicate its function is termed the spreader. These annular discs may be brazed
to the ends of the bundle or heated and shrunk upon the ends of the bundle or
otherwise securely held to the ends of the bundle in any convenient manner. They
form virtually a part of the core and are preferably as large again as the diameter
of the core, their function being to enlarge or spread the area of the magnetic
field. As a matter of convenient construction longitudinal rods C, C are laid
parallel with the bundle forming the core and are extended through the spreaders
to hold all the parts together firmly. These rods may be imbedded among the
outer wires of the core which are somewhat shorter than those forming the body
thereof and are held in place by the spool heads D, D.
In winding each spool of the magnet two special features are adopted, either one
of which is productive of certain good results, while the two together are main
factors in accomplishing the principal results aimed at. The first of these two
steps in the method of winding is the decrease of the size of the winding wire or
wires, from the core outward. One, two or more layers immediately about the core
are formed of heavy wire, as indicated at e, e. The one, two or more layers next
outside of these are formed of smaller wire, as indicated at f., and so on to the
outside of the spool, the finest wire being on the outside. The number of sizes of
wire employed and the number of layers formed with each size may be varied more
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page_text: or less as desired or as found productive of the best results under particular
conditions of use. For a purpose to be referred to hereinafter the end of successive
wires of different sizes are not connected directly together but are brought out at
the end of the coil, as clearly shown at el, e, f, f¹, and g¹, g' in Figures 1 and 2.
The ends are preferably provided with jacks e, f, g, and a plug board H is
mounted in proximity to the magnet so that the ends of the different wires can be
coupled together in any desired manner.
The other step in the method of winding referred to and one which is essential
to the attainment of the desired result whether wires of different sizes be employed
or not is the reversing of the direction of winding of the wire about the core at the
end of every second layer. This is clearly illustrated in Figures 3, 4 and 5, each
one of which figures indicates the manner of winding of the successive layers of
wire upon a single core, there being for each double layer two representations of
the core so that the direction of winding both to and fro upon the core may be
indicated. Thus in Figure 3 the heavy wire e which lies nearest to the core is
represented as being wound about the same in a direction opposite to the direction of
movement of the hands of a watch in both the first layer, when the winder is moving
forward, and in the second layer when the winder is moving back toward the end
at which its movement commenced. To make the illustration clearer but two
layers of the first or heaviest wire are represented, but it will be understood that
there may be two, four, six or more as may be found desirable, but at the end of
every second layer the direction of winding is reversed, as more fully illustrated
with respect to the second and third wires.
The second wire fis wound upon the last layer of the first wire with the direction
of winding reversed, that is to say, if the direction of winding of the two layers
immediately preceding was opposite to the direction of movement of the hands of a
watch, the direction of winding of these next two layers, to and fro, is the same as
the movement of the hands of a watch. Of the second wire f as of every other
wire, there may be two, four or more layers and as before stated the direction of
winding is reversed at the end of every second layer; consequently as indicated in
Figure 5 and in Figure 6 each wire, if not cut and having its end extended out
from the coil, must be bent upon itself to form a bight, as at x in Figure 6, and
wound on over the preceding layer in the direction opposite to that in which such
preceding layer was wound. Such bight is secured in any convenient manner, as
by a bit of taping, and it is evident that wherever there are four, six or more layers
formed from one wire there will be a bight at the end of every second layer until
the end of the wire is reached. The winding of the third wire g and of every
Buccessive wire is conducted in a similar manner. It will be understood that
whether a single wire be used or several different sizes of wire be used in succession,
the direction of winding is reversed at the end of every second layer. It will also
.be understood that when several wires of different sizes are used each wire forms
an even number of layers and that the ends of each wire are brought outside of the
coil to be connected up in any one of the several different ways which are possible,
as may be found most desirable.
A yoke I of soft iron is secured to the spreaders B, B at one end of the magnet,
having a width preferably equal to the diameter of the spreaders, and having a
length preferably equal to half the length of one of the cores.
The object which was especially in view in this invention was the production of
a magnet which, being thoroughly protected against injury by water, might be
suspended from a float, and might have a field of such magnitude and intensity that
when brought into proximity to a ship, particularly an iron or steel vessel, it might
have sufficient power to affect the compass lever or even to establish lines of
magnetic force in the hull and machinery of the vessel itself, to the discomforture
of the navigator or the derangement of the mechanism on board. It will be readily
understood, however, that the improvement is not limited in its applicability to such
use or to any other particular use.

page_text: 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. An electro magnet having fixed to the end of its core a soft iron disc of a
diameter considerably larger than the diameter of the core, substantially as shown.
and described.
2. An electro magnet having a core composed of a bundle of parallel wires and
having soft irou, annular discs of considerably larger diameter than the core.
encircling and binding said wires together at their euds, substantially as shown and
described.
3. An electro magnet having its coils formed of a series of wires, the ends of
said wires projecting from the coil, and means whereby said wires may be connected
and disconnected as desired, substantially as shown and described.
4. An electro magnet having its coils formed of a series of wires of different.
sizes, the larger wires forming the layers near the core, and the finer wires forming.
the layers near the outside, substantially as shown and described.
5. An electro magnet having its coils about the core formed of successive layers.
of wire, the direction of the wire being reversed at the end of every second layer,.
substantially as shown and described.
6. The improvement in the method of winding electro magnets which consists in.
winding successive layers of wire upon the core and reversing the direction of
winding at the end of every second layer.
Dated this 21st day of Santambar 1805
MARKS & CLERK,
18 Southampton Buildings, London, W.C., and
13 Temple Street, Birmingham, Agents for the Applicant..