IMPROVEMENTS IN ELECTRO MOTORS
Year: 1883

page_text: LETTERS PATENT to Samuel Joseph Coxeter and Heinrich Nehmer of
23 Grafton Street East in the County of Middlesex for an Invention of
IMPROVEMENTS IN ELECTRO MOTORS
PROVISIONAL SPECIFICATION left by the said Samuel Joseph Coxeter
and Heinrich Nehmer at the Office of the Commissioners of Patents on the
2nd October 1883.
SAMUEL JOSEPH COXETER and HEINRECH NEHMER of 23 Grafton Street East
in the County of Middlesex IMPROVEMENTS IN ELECTRO MOTORS.
Whereas armatures of small electro motors have usually the shape of a long
cylinder with a small circumference, and therefore but little centrifugal force-Wo
prefer to make our motor with an armature that has the shape of a short cylinder
with a large circumference, in order to obtain better centrifugal force :--and we
also confine the magnetic field within a narrow space.
One way in which we do this is preferably as follows:-
The armature consists of a narrow iron wheel, or disc, across and around which,
we wind a coil or coils of wire: this wheel or disc revolves within a ring of iron-
coils of wire on opposite sides around this ring, induce the magnetic field-when
a current is passed through them; the circuit of the coils is completed in the usual
way.
Another feature of our Invention is that motors so constructed, have their
armatures acted upon by the electro magnets, to a greater extent, than électro-
motors otherwise constructed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Samuel Joseph Coxeter and Heinrich Nehmer in the Patent Office
on the 2nd April 1884.
SAMUEL JOSEPH COXETER, and HEINRICH NEHMER, of 28 Grafton Street East
in the County of Middlesex "IMPROVEMENTS IN ELECTRO MOTORS"
Whereas armatures of electro motors more especially those of small size have
usually the shape of a long cylinder with a small circumference and therefore but
little centrifugal force, we prefer to make our motor with an armature that has the
shape of a short cylinder with a large circumference, in order to obtain better
centrifugal force.
One way in which we do this preferably is as follows:-The armature has
the shape of a narrow wheel or disc, and may be made of one piece of iron
or built up of several pieces as desired-Across and around this narrow wheel
or disc, we wind a coil or coils of wire; this wheel or disc revolves within a
ring of iron; coils of wire on opposite sides around this ring induce the magnetic
field; when a current is, passed through them, the circuit of the coils is completed
in the usual way-Another feature of our Invention is that motors so constructed
have their armatures acted upon by the electro magnets to a greater extent than
electro motors otherwise constructed.
In order that our Invention may be clearly understood, we now proceed to
further describe the same by reference to the accompanying Drawings:-
Fig. 3 an end elevation
Fig. 4 a sectional plan through the line A A
and Fig. 5 a sectional elevation through the line B B of an electro motor constructed
according to our Invention.
Fig. 6 is an elevation and Figs. 7 and 8 are sections of an armature constructed
according to our Invention
The same numbers refer to the same parts in each figure
The armature is formed of a disc of soft iron 1, the diameter of which considerably
exceeds its thickness or length on the axis.-It is recessed as shown at 2, 2, (Figs. 4,
5, 6, 7 and 8) to receive the wire to form the coil 3, and is provided with an axis 4,
which is supported in bearings in strips of metal 5, 5. Strips of insulating material
6, 6, are provided to make up the thickness of the axle in the coil.-In this armature
80 wound, the longer direction 7, 7, of the coil 8, 3, is at right angles to the axis,
and the shorter, 8, 8, is parallel with the axis-Instead of passing the axle through
the armature, as shown in Figs. 4, 5, 6, and 7, we may if preferred form the axle
in two portions attached to the armature by strips of metal 9, 9, as shown in
Fig. 8; by this means, the strips of insulating material 6, 6 may be dispensed
with, and more space obtained for the coil.-The armature may be formed of one
piece of iron, as shown in Figs. 4, 6, and 8, or may be built up in layers, as shown
in Fig. 7.-The magnetic field within which the armature revolves, is made of a
ring of soft iron 10 and 11, of the form shown in Fig. 1. It may be of the same
thickness as the disc of which the armature is composed, and is constructed in two
portions 10, 11, which are united together by being screwed to the soft iron
cores 12, 12, of the coils 13, 13-These coils are so wound that both their north
poles are attached to 10, and both their south poles to 11, or vice versa, so that the
whole of 10 becomes a north pole, and the whole of 11 a south pole accordingly—

page_text: By arranging the coils of the field magnets in the position shown in Figs. 1, 2,
and 3, which is contrary to that usually adopted, the machine is rendered very
compact in form.-The metal strips 5, 5, which support the axis of the armature,
also serve as an additional connection 'for the two halves of the field magnets.―
In practice, this magnet is constructed in one piece, and afterwards cut through at
the points 14, 14, the coils 13, 13, with their cores 12, 12, being then screwed in
position-If desired, we may divide it into more than two portions,-An electric
current from a galvanic battery, or from a dynamo, etc: being passed through the
coils of our electro motor in the usual way, the armature will revolve, and the
motion thus obtained, may be communicated to any machine or other apparatus.―
If, in an electro-motor constructed according to our Invention, instead of passing
a current through the machine, we cause the armature to be rotated by steam,
manual, or any other power, it is obvious that the machine will itself generate an
electric current which may be employed for medical or surgical purposes, to light
electric lamps, to put in motion another electro motor, to charge accumulators, or
for any other purpose to which such currents are applied in the ordinary way;
therefore machines constructed according to our Invention may be used either as
electro-inotors, or as current generators.
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
we claim is :-
(1.) The construction of an electro motor or current generator, substantially as
and in the manner described in this specification, and shown in the Drawings
attached thereto.
(2.) The construction of an armature of an electro motor or current generator
in the form of a disc, the diameter of which is much greater than its thickness or
length on the axis, as shown in Figs. 4 and 5.
(3.) The arrangement of the coils upon the armature of an electro motor or
current generator, so that the longer direction of the coil is at right angles to the
axis of the armature, and the shorter parallel to the axis.
(4.) The peculiar design and arrangement of the field magnets and coils of an
electro motor or current generator, as shown in Figs. 1 2, and 3, by which the
machine is rendered very compact.
(5.) The combination of the arrangement of field magnets and armature, by
which the armature is acted upon by the field magnets to a greater extent than in
electro motors and current generators otherwise constructed.
In Witness whereof we the said Samuel Joseph Coxeter and Heinrich Nehmer
have hereunto set our hands and seals this second day of April one thousand eight
hundred and eighty four
Witness
AMBROSE MYALL
SAMUEL JOSEPH COXETER (L.S.)
HEINRICH NEHMER
(L.S.)