IMPROVEMENTS IN SOME FORMS OF ELECTRO MAGNET AND SOLENOID CORES
Year: 1884

page_text: I HENRY FRANCIS JOEL of 44 Lavender Grove, Dalston, London, in the County
of Middlesex Electrical Engineer do hereby declare the nature of my Invention for
IMPROVEMENTS IN SOME FORMS OF ELECTRO MAGNET AND SOLENOID CORES, to be
as follows:
My invention relates to the iron cores of electro magnets and solenoid coils
made in the form of cone or double cone or spindle or such like shape. I make
such iron cores of a tape, ribbon or narrow strip of sheet iron, instead. of solid iron
usually employed.
I coil the strip upon a single cone or double ended cone or spindle, or such other
shaped mandril, and thus make a hollow conical shaped core. I may fill up either
of these forms with iron filings or lengths of iron wire. I also take a strip or sheet
of wrought iron of a rhomboid, circular or triangular or other suitable shape and
coil this sheet upon itself, commencing from one corner, or in such a way that I can
make what is practically a solid cone shaped or spindle shaped or other such shaped
iron core in which the greatest mass of iron is at the thickest part of the core and
from that point tapers off as desired. In all or any of these cores I may insulate
the coilings one from the other by means of prepared tape or by varnishing,
oxydizing or otherwise preparing the surfaces of the iron.
The essential object of the use of the coiled sheet iron cores insulated as
described, being to avoid the loss due to so called Foucault currents, and to ensure
that the softest iron is used, and thus render the cores, especially of Electric Light
Arc Lamps, more sensitive in their action, and suitable for use, with either
continuous, or alternating currents. I may galvanize the sheet iron for the
purposes of magnetic insulation.
Dated third day of December 1901

page_text: COMPLETE SPECIFICATION.
Improvements in Some Forms of Electro Magnet and Solenoid
Cores.
I, HENRY FRANCIS JOEL, of 44 Lavender Grove, Dalston, London, in the
County of Middlesex, Electrical Engineer do hereby declare the nature of my
invention for "IMPROVEMENTS IN SOME FORMS OF ELECTRO MAGNET AND SOLENOID
CORES "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 the iron cores of electro-magnets, and solenoid coils
made in the form of cone or double cone or spindle, or such like shape. I make
such iron cores Figs. 1 and 2 of a tape, ribbon or narrow strip of sheet iron, instend
of solid iron usually employed. I coil the strip upon a single cone Fig. 2, or double
ended cone Fig. 1, or spindle, or such other shaped mandril, and thus make a hollow 1
conical shaped core; I may fill up either of these forms with iron filings or lengths
of iron wire, as shewn in dotted lines in Fig. 2.
I also take a strip or sheet of wrought iron (see Figs. 3, 4, 5 and 6) of a
rhomboid, circular or triangular or other suitable shape, and coil this sheet upon
itself commencing from one corner, or one end, as shewn in Fig. 3, or in such a
way that I can make what is practically a solid cone shaped, (Fig. 6,) or spindle
shaped (Figs. 3 & 5) or other such shaped iron core in which the greatest mass of
iron is at the thickest part of the core, and from that point tapers off as desired.
In all or any of these cores I may insulate the coilings one from the other by
means of prepared tape or by varnishing, oxidizing, or otherwise preparing the
surfaces of the iron.
The essential object of the use of the coiled sheet iron cores insulated as
described, being to avoid the loss due to so called Foucault currents, and to ensure
that the softest iron is used, and thus render the cores, especially of Electric Light
Arc Lamps, more sensitive in their action, and suitable for use, with either
continuous, or alternating currents.
I may galvanize the sheet iron for the purposes of magnetic insulation.
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
The construction of iron cores for Electro-Magnets, and Solenoids, substantially
as shewn and described.
013
1100K