Electro-magnets.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Electro-magnets.
We, RICHARD VARLEY, Jr., of Knickerbocker Road, Englewood, in the
County of Bergen and State of New Jersey, United States of America, Electrician,
and FRANK CAZENOVE JONES, of 3 West 74th Street, New York, in the County
of New York and State of New York, United States of America, Manufacturer,
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 and accompanying drawings:-
In the manufacture of electro-magnets it has heretofore been usual to employ
wire with a covering of silk or other material to insulate the same, and to wind the
wire around the core, and in the compound winding of magnets and induction coils
two wires have in some instances been wound together.
Our present invention is adapted to any character of electro-magnet, but it is
advantageously applied to the cheaper kinds of magnets employed in call bells,
spark coils and alarms. By our present improvements we are enabled to lessen
the expense of the magnet and to introduce the same number of coils and convo-
lutions into a smaller space, or to increase the number of convolutions without
increasing the size of the magnet, thereby promoting the efficiency of the same.
In carrying out our invention we use two wires, one a wire covered with
insulating material, such as a winding of silk or other fibrous material, or insulated
in any other suitable manner, and the other wire a plain or naked wire, and these
two are wound side by side, and the layers of coils or helices are insulated from
each other by paper or similar material, and in consequence of the convolutions of
the covered wire alternating with the convolutions of the plain wire, the plain wire
is kept from contact, the one convolution with the other, and much less space is
required because the space occupied by the covering of one wire is dispensed with.
The ends of the helices are connected up in series, so that the current traverses
both the coils in the same direction; thereby obtaining the* greatest magnetic
efficiency from a given current.
.In the drawing
Figure 1 is an elevation of our improved magnet partially wound;
Fig. 2 is a diagram illustrating the manner of winding and of connecting the
respective helices of one core; and
Fig. 3 is a similar diagram showing the connections of the wires for two cores.
Upon the core A is any suitable spool having heads B, B and a suitable insulating
tube between the metal of the core and the first coil of the wire, and a complete
layer of paper C is to be applied around each layer as coiled up in succession, so as
to insulate one layer from the other. The wire D is covered with insulating
material such as silk or other fibre braided or twisted thereon, or an insulating
material or covering of any other suitable character, and the wire E is plain, and
these wires are wound parallel and simultaneously, so that the coils of the plain
wire E intervene between the coils of the covered wire D, and the winding is to be
continued in layers, with the insulation of paper or other material between, until
the spool or helix of the proper size is completed, care being taken to allow the
inner ends D and E¹ to project, and after the helix or spool is completed, the two
coils or helices are connected in series by joining the ends E2 and D', so that the
current will pass in by D2 and through the covered helix D, thence by the end D'
to the end E and through the helix E of plain wire and away by the end E' to the
negative of the generator, thus obtaining great efficiency in the magnet and reducing
the expense and the size of the helix and causing the current to pass through both
helices in the same direction to obtain the greatest magnetic efficiency.

page_text: While we find it advantageous to employ one covered and one naked wire, the
connections of two wire helices in series as aforesaid might be effected even in
instances where both wires were covered.
Where an electro-magnet is composed of two cores and two helices, as in Fig. 3,
the outgoing ends E', D' of one helix may be joined to the ingoing ends E, D2 of
the next helix, and at the other end, the wires D¹, E2 may be connected and the
wires E' and D2 will form the electrodes or pass to the battery or other source of
electric energy, or the connections may be made in other suitable ways which will
permit the plain and covered wires to act in co-operation in developing magnetism in
the core or cores.
In many characters of electro-magnets the principal expense is in the insulation
of the wire, because the covered wire is so much more expensive than the same
wire uncovered; for this reason we are enabled to lessen the expense to a very
large extent because only half the amount of covered wire is required in obtaining
the same magnetic potential.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :
1. The combination in an electro-magnet of the helix composed of two parallel
wound wires, one being covered, and the other uncovered, and one layer of wire
insulated from the next layer of wire, substantially as set forth.
2. An electro-magnet having a helix of two parallel wires, one with a fibrous
covering and the other without a fibrous covering, and wound in layers insulated
one from the other, substantially as set forth.
3. An electro-magnet having a helix of two similarly sized parallel wires, one
with a fibrous covering and the other without a fibrous covering and wound in
layers insulated one from the other, substantially as set forth.
4. An electro-magnet having a helix of two parallel wires, one with a fibrous
covering and the other without a fibrous covering and wound in layers insulated one
from the other and the ends of the respective helices connected directly together,
'substantially as set forth.
Dated this 21st day of December 1892
E. K. DUTTON & Co.,
5, John Dalton Street, Manchester, Agents.