Improvements in Windings for Armatures of Dynamo-electric Machines and Motors.
Year: 1896

page_text: Date of Application, 25th Feb., 1896-Accepted, 28th Mar., 1896
COMPLETE SPECIFICATION.
Improvements in Windings for Armatures of Dynamo-electric
Machines and Motors.
1, JAMES DEVONSHIRE, Secretary of the British Thomson-Houston, Limited,
of 38, Parliament Street, Westminster, London, (a communication from abroad by
Walter H. Knight, Electrical Engineer, of Schenectady, in the State of New
York, United States of America), 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 present invention relates to windings for armatures of dynamo-electric
machines or motors, and particularly to the individual coils of which such armature
windings are composed; and has for its object to provide a coil adapted for use
upon an armature core having slots, which may be readily manufactured by methods
making the coils interchangeable and greatly facilitating repairs to the winding
should any of the coils become damaged, at the same time being otherwise
economical in the length of wire and in the facility of manipulation.
Nearly all armature coils are now wound separately and separately insulated,
but most of the forms of such coils with which I am acquainted, have been trouble-
some to make, on account of their peculiar shapes, and still more troublesome to
put in place on account of the curvilinear distortion on the ends of the drum, which
is rendered necessary by the peculiar overlapping in armatures of this description.
I have discovered, however, that I may wind my armature coil in an open figure of
six sides, all the sides being straight during the process of winding. The longer
sides of the two trapeziums, having a common open side, of which the coil is
composed, are adapted to be inserted in the slots of the armatures, while the shorter
sides span the space on the end of the drum, and when seen in end elevation form
what I call a "chordal" winding. The approximately radial portion of the coil
joining the two shorter sides is drawn down in the process of applying the coil to
the armature so that the ends of the armature present a somewhat peculiar
appearance, a plan of the completed structure being a cylinder with two short
parabolic curves at its ends.
The accompanying drawings show an embodiment of my invention,
Fig. 1 being a side elevation of a portion of an armature core having some of
the coils applied thereto;
Fig. 2 being a plan view upon a smaller scale of a drum armature constructed
according to my invention, and
Fig. 3 being a plan view of one of the coils.
A
Referring by letter, A is the body of the armature, provided with slots a, a;
B, B are the coils, each composed as seen in Figs. 1 and 3, of the sides b, b passing
through the slot to the sides 61, 63, which pass across the end of the armature.
radial portion 63 is formed in the process of manufacture and permits the peculiar
arrangement seen in Fig. 1.
The two parts of the coil thus lie in different, but parallel planes, and the two
trapeziums having their common side missing which form these two parts of the
coil are united by portions approximately radial to the circumference of the core
to which the coil is to be applied.
In Fig. 2 the peculiar shape of the winding as a whole which I have described
in my statement of invention, is illustrated, the parts being lettered as before.
The parts of the winding which I have lettered 62 in the lower part of the figure,
form in plan a portion of a paraboloid of revolution or approximate parabolic

page_text: curve of that nature, and the winding as a whole is quite distinctive in appearance
as applied to the armature.
As indicated in Fig. 3, it is designed to wind the coils separately and they are,
as is usual in such constructions, afterwards wound with tape and dipped in shellac
or suitably insulated in any other desirable manner; and the further mechanical
details of the construction will not be pointed out, inasmuch as they are well known
in the art.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me
from abroad I declare that what I claim is:
1. An armature coil for a dynamo-electric machine or motor, composed of a six-
sided figure, the two halves of which lie in different but parallel planes and are
united by a portion approximately radial to the circumference of the armature core,
2. An armature coil for a dynamo-electric machine or motor, made in the shape
of a six-sided figure composed of two trapeziums having their common side missing,
and lying in different but parallel planes, the two trapeziums united by portions of
the coil approximately radial to the circumference of the core to which it is to be
applied.
3. An armature for a dynamo-electric machine, having a slotted core and
windings disposed in the slots upon the face of the armature, the windings consisting
of individual coils, each being in the shape of a six-sided figure composed of two
trapeziums having their common side missing and lying in different but parallel
planes, the two trapeziums united by portions of the coil approximately radial to
the circumference of the core to which it is to be applied.
Dated this 25th day of February 1896.
For the Applicant,
J. C. CHAPMAN,
70 Chancery Lane, London, W.C., Chartered Patent Agent.