IMPROVEMENTS IN THE CONSTRUCTION AND ARRANGEMENT OF THE CORES AND ARMATURES AND OTHER PARTS OF ELECTRO MAGNETS.
Year: 1882

page_text: LETTERS PATENT to Stanley Charles Cuthbert Currie of No: 121 Warwick
St: London S. W. in the County of Middlesex Gentleman for an
Invention of IMPROVEMENTS IN THE CONSTRUCTION AND ARRANGEMENT OF
THE CORES AND ARMATURES AND OTHER PARTS OF ELECTRO MAGNETS.
PROVISIONAL SPECIFICATION left by the said Stanley Charles Cuthbert
Currie at the Office of the Commissioners of Patents on the 4th August 1882.
STANLEY CHARLES CUTHBERT CURRIE of No: 121 Warwick Street, London,
S.W. in the County of Middlesex, gentleman IMPROVEMENTS IN THE
CONSTRUCTION AND ARRANGEMENT OF THE CORES AND ARMATURES AND OTHER
PARTS OF ELECTRO MAGNETS.
The objects of this Invention are to provide Electro magnets that shall have a
maximum of power with a minimum of resistance and cost-A great want in
Electro magnets is to get a magnet which, with a small current, shall utilize the
greatest portion of that current by having a small resistance, with a maximum of
induction and a large magnetic field-If these ends are attained a number of
electro magnets may be placed in series, over a long length of conducting wire
and (supposing the magnets are used for the purposes pointed out in my patent
No: 632 Feb 9 1882 viz: of providing means for pulling levers) a continuous
current of small power can be transmitted and a pull of great force given to each
magnet at a small cost-The pull will not only be a powerful one but will have a
long stroke-The objects, further, are not only to provide Electro magnets with a
strong, long-stroke, pull for working Railway signal levers but also to provide the
strongest and most economical Electro magnets for any purposes where they are
useful.
With these objects in view, I make an inner Cylindrical core of soft Iron of any
suitable thickness diameter or length and at any suitable distance outside it I put
another Cylinder of the same length and of such a thickness that the ratio of the

page_text: sectional area of the one to the sectional area of the other may be such that the
magnetic influence of the two shall be equal-These two Cylinders rest upon a
circular soft Iron plate. The space between the inner and outer Cylinders described
above is filled in with one or more coils of wire which may be formed of insulated
wire of one system or split up into two or more systems according to the particular
purpose for which the magnet is required-At one or both ends, if necessary, I put
a disc of brass or other diamagnetic substance to keep the coils in place.
The reason for putting a cylinder outside the coil or coils as well as inside is
that both are magnetised by the one coil and further strengthened by their opposite
poles being connected by the circular plate on which they rest. The plate itself
also being acted upon by the current in coil-There may be two or more cylinders
each separated by a coil of suitable thickness.
Within the inner core or cylinder I put a rod of soft Iron encased in brass or
other diamagnetic substance (to prevent it sticking to the inner cylinder) so that
it slides easily but not too loosely or too tightly therein. This rod is screwed or
fastened to, or made a part of, and the same piece with, a circular plate of soft
Iron which is of course, at the opposite end of the magnet to the circular soft
Iron plate mentioned above and the whole acts as an armature.
The object of this centre rod of Iron sliding within the inner cylinder is that
being acted upon by the current in coil and polarised longitudinally thereby, it
polarises the circular plate to which it is attached radially and in such a way that
the attraction is increased between the plate (which acts as an armature) and the
outer cylinder thus increasing the total pull on the armature.
Round the outside of the circular plate which is attached to the centre rod-I
put a thin ring of Iron or other suitable metal of such a depth as to project round
the plate towards the outer cylinder (though it may be made to project towards
one of the other Cylinders) above mentioned and is, by preference, of such a
diameter that it will just slip over the latter without touching it-This rim may
have a plain or serrated edge the object of which is that its edge is nearer the
cylinder than the plate to which it is attached is to that cylinder, and it is
therefore drawn towards the latter and thereby brings the plate with it until it
(the plate) is acted upon by the cylinders and hence the total pull is lengthened. Of
course the size depth and shape and quality of the ring depends upon the nature
of pull required. This outer ring may be attached directly to the circular
plate or with a thin ring of brass or other diamagnetic substance between, this
depending upon the strength and distribution of pull required. Of course the ring
may consist of one or more pieces or sheets of metal with or without diamagnetic
layers between them.
Instead of soft Iron as specified herein, soft steel or other suitable metal may be
used because I would remark that it is possible to make a metal other than Iron
which when magnetised can be quickly demagnetised. And where one sheet or ring
of metal is described herein, the sheet or ring may be made of one two or more
pieces or sheets of Iron or other suitable metal without interfering with the
objects of this Invention.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Stanley Charles Cuthbert Currie in the Great Seal Patent Office on
the 3rd February 1883.
STANLEY CHARLES CUTHBERT CURRIE of N° 121 Warwick Street, London
in the County of Middlesex Gentleman "IMPROVEMENTS IN THE CONSTRUCTION
AND ARRANGEMENTS OF THE CORES AND ARMATURES AND OTHER PARTS OF
ELECTRO-MAGNETS "
The objects of this Invention are to provide Electro-magnets that shall have a
maximum of power with a minimum of resistance and cost. A great want in
Electro magnets is to get a magnet which with a small current shall utilize the
greatest portion of that current by having a small resistance with a maximum of
induction and a large magnetic field. If these ends are attained a number of
electro magnets may be placed in series over a long length of inducting wire and
supposing the magnets to be used for the purposes pointed out in my Patent
No 632/ viz of providing means for pulling levers a continuous current of small
power can be transmitted and a pull of great force given to each magnet at a small
cost. The pull will not only be a powerful one but will have a long stroke. The
objects further are not only to provide Electro magnets with a strong, long stroke
pull for working Railway signal levers but also to provide the strongest and most
economical Electro magnets for any purposes where they are useful.
With these objects in view I make an inner cylindrical core of soft iron of any
suitable thickness diameter or length and at any suitable distance outside it I put
another cylinder of the same length or any other suitable length and of such a
thickness that the ratio of the sectional area of the one may be such that the
magnetic influence of the two shall be equal. These two cylinders rest upon a
circular soft Iron plate. The space between the Inner and outer cylinder before
described is fitted in with one or more coils of wire which may be formed of
insulated wire of one system or split up into two or more systems according to the
particular purpose for which the magnet is required. At one or both ends if
necessary I put a disc of brass or other diamagnetic substance to keep the coils in
place.
The reasons for putting a cylinder outside the coil or coils as well as inside is
that both are magnetized by the one coil and further strengthened by their
opposite poles being connected by the circular plate in which they rest.
The plate
itself also being acted upon by the current in coil. There may be two or any
other suitable number of cylinders each separated by a coil of insulated wire of
suitable thickness.
Within the inner core or cylinder I put a rod of any suitable size or length of
soft Iron encassed in brass or other diamagnetic substance (to prevent it sticking to
the inner cylinder) so that it slides easily but not too loosely or too tightly therein.
This rod is screwed or fastened to or made a part of and the same piece with a
circular plate of soft iron which is of course at the opposite end of the magnet to
the circular soft Iron plate hereinbefore mentioned and the whole acts as an
armature.
The object of this centre rod of Iron encassed in brass or other diamagnetic
substance sliding within the inner cylinder is that being acted upon by the current
in coil and polarised longitudinally thereby, it polarises the circular plate to which

page_text: it is attached radially and in such a way that the attraction is between the plate
(which acts as an armature) and the outer cylinder thus increasing the total pull
on the armature.
Round the outside of the circular plate which is attached to the centre rod I
put a thin ring of Iron or other suitable metal of such a depth as to project round
the plate towards the outer cylinder (though it may be made to project towards
one of the other Cylinders) above mentioned and is by preference of such a
diameter that it will just slip over the latter without touching it. This rim may
have a plain or serrated edge the object of which is that its edge is nearer the
cylinder than the plate to which it is attached, is to that cylinder, and it is therefore
drawn towards the latter and thereby brings the plate with it until it (the plate)
acted upon by the cylinders and hence the total pull is lengthened. Of course
the size, depth and shape and quality of the rim depends upon the nature of pull
required. This outer rin may be attached directly to the circular plate or with a
thin ring of brass or other diamagnetic substance between this depending upon the
strength and distribution of pull required. Of course the ring may consist of one
or more pieces or sheets of metal with or without diamagnetic layers between
them.
Instead of soft Iron as herein before described soft steel or other suitable inetal
may be used because I would remark that it is possible to make a metal other than
Iron which when magnetized can be quickly demagnetised and where one sheet or
ring of metal is described herein, the sheet or ring may be made of one two or
more pieces or sheets of iron or other suitable metal without interfering with the
obiects of this Invention
Figure 1 is an elevation of an electro magnet in which the said Invention is
embodied. Figure 2 is a vertical section of the same.
a is the inner cylindrical core of soft Iron or soft steel or any other suitable
metal, made of any convenient thickness, diameter or length. On the outside of
which is another cylinder b of the same length or any other convenient length and
of such a thickness that the ratio of the sectional area of the one, to the sectional
of the other may be such that the magnetic influence of the two shall be equal
the one to the other. The two cores resting on a soft iron plate c
The space
between the inner and outer cores is filled up with insulated wire d of one or more
systems (but only represented as one system in Figure 2 of the Drawings)
according for what purpose the magnet is required. c is a disc of brass used to
keep the coils of wire d in their place when coiling. Within the inner core or
cylinder a rod f of any suitable size as shown in Figure 2 encassed wholly or partly
by brass or other diamagnetic substance g is made to work.
The rod is screwed to the circular plate ȧ by the screw mit can also be made
a part of the plate i or fastened in any other convenient way. Round the circular
plate which acts as the top part of the armature is a thin rim made of iron or other
suitable metal n. This rim may have a plain or serrated edge but a serrated edge
is shown in both Figures for the purpose of illustration but it must be understood
that I do not confine myself to this serrated edge. This rim n may be attached to
the circular plate directly or it can be screwed thereto.
Having now described the nature of the said Invention & the manner in which
the same is or may be carried into effect I claim.
:
First The combination of the outer cylinder together with the Inner
cylindrical core both fastened to the bottom plate and one or more systems of
insulated wire in order to get a maximum of magnetic induced force with the
smallest resistance substantially as and for the purposes herein before described.
Secondly-The rim or rims serrated or plain fastened to the outer circumference

page_text: of the armature plate together with the centre rod encassed wholly or partly in
brass or other suitable diamagnetic substance fastened to the centre of same
substantially as and for the purposes herein before described.
In witness whereof I the said Stanley Charles Cuthbert Currie have hereunto
set my hand and seal this thirty first day of January in the year of our
Lord one thousand eight hundred and eighty three
STANLEY C. C. CURRIE (L.S.)