Improvements in Armatures for Dynamo-electric Machines and Electric Motors.
Year: 1893

page_text: Date of Application, 3rd Oct., 1893-Accepted, 4th Nov., 1893
CUMT LINIE OF DUIFICATION.
Improvements in Armatures for Dynamo-electric Machines and
Electric Motors.
I, MARTIN RAHNER, residing at 132 Jefferson Street, in the Town of Union, in
the County of Hudson and State of New Jersey, United States of America,
Electrician, 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 :-
This invention relates to armatures for dynamo-electric machines and electric
motors; and the object of my present invention is to provide a new or improved
armature which is simple in construction and from which any one coil can easily and
readily be removed without disturbing any of the others.
The invention consists in a combination with a shaft of end-plates on the same a
series of core pieces held between said end-plates and a separate and independent
coil on each core piece.
The invention also consists in the construction and combination of parts and
details which will be fully described hereinafter and finally pointed out in the
claims.
In the accompanying drawings
Fig. 1 is a longitudinal sectional view of my improved armature showing one
core wound and the others bare.
Fig. 2 is a vertical transverse sectional view of the completed armature.
Similar letters of reference indicate corresponding parts throughout.
The armature is mounted on the shaft A carrying the usual commutator B which
may.be of any desired construction. On said shaft A two end discs C C of non-
magnetic material for example brass are mounted and between said discs a series of
core pieces D are mounted radially which core pieces increase in thickness from
their inner toward their outer edges.
Each core piece is provided at each end and at the outer edge with a lug E and
at the inner edge it is provided at each end with a corresponding lug E¹.
The lugs E are provided with threaded apertures and bolts Fare passed through
apertures in the end plates C and screwed into the lugs E said bolts being provided
with heads at their outer ends-
s-or other suitable means of securing the core pieces
in position may be used.
A coil H of insulated wire is wound on each core piece D in such a manner as to
increase in thickness from the inner toward the outer edge as shown in Fig. 2 so
that the sides of two adjacent coils rest against each other. Said coils are formed
in the usual manner and proper insulating material is used between the several
windings. The ends of the coils H are connected with the commutator sections in
any suitable manner.
Each and every core piece D and the coil H thereon is entirely independent of
any other coil and core-piece and can be removed from the armature without
disturbing any such other coil all that is necessary being to remove the screws (or
other fastenings) F when the core piece and its coil can be removed.
LL are mica insulating plates.
In case by accident any one armature section or coil burns out it can easily be
removed and replaced by another. The surfaces of the coils are not at the outer
periphery of the armature but the outer edges of the core pieces are at said
periphery. In case the Babbit metal or other lining of the bearings melts and the
shaft A becomes displaced only the outer edges of the core pieces D can come in
contact with the pole pieces and thus there is no danger of scraping the covering

page_text: off the wires of the armature as frequently happens in the armatures used
heretofore.
Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In an armature the combination with a shaft of two end discs on the same a
series of core pieces held radially between the end plates and fastened to said end
plate by bolts or fastenings passed through said end plates into the ends of the core
pieces and a separate and independent coil on each core piece substantially as set
forth.
2. In an armature the combination with a shaft of two end plates on the same a
series of core pieces held radially between the end plates which core pieces are
provided with end lugs at the outer and inner edges screw bolts or other suitable
fastenings passed through the end plates into the outer lugs of the core pieces and
a separate and independent coil on each core piece substantially as set forth.
Dated this 3rd day of October 1893.
TONGUE & BIRKBECK,
34, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.