Improvement in Fastening Means for Core Plates of Electrical Machines.
Year: 1897

page_text: Date of Application (in the United Kingdom), 12th July, 1897
Complete Specification Left, 6th Apr., 1898-Accepted, 20th May, 1898
PROVISIONAL SPECIFICATION.
Improvement in Fastening Means for Core Plates of Electrical
Machines.
I, EDWIN EMERSON NOLAN, of 517, Center Street, Wilkinsburg, in the County
of Allegheny, State of Pennsylvania, one of the United States of North America,
Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:
My invention relates to the cores of electrical machines, and has for its object
to provide an improved means for securing in position the laminae or core plates
forming said cores.
According to my invention the casting on or to which the laminae are to be
secured is provided with a flange at or near one end, and at the other end has a
circumferential groove which forms a shoulder. After the laminae have been
assembled in position on or in the core an annular plate similar to but thicker
than the laminae is placed in position and temporarily secured so that the laminae
are clamped between it and the end flange of the casting. After the plate has
been pushed sufficiently far towards the flange to expose the circumferential
groove a spring ring or segments forming a ring are placed in the said groove so
as to project outside of the same and in the path of the annular plate, and to
prevent the same from moving back and releasing the laminae. In order to
prevent accidental displacement of the fastening ring the annular plate is prefer-
ably provided with a shoulder on its outside which engages with the exterior of
said ring and holds it in the circumferential groove in the casting.
When it is desired to dismember the core, the annular plate is pressed by any
suitable means towards the flange so as to release the fastening ring which is then
removed from its position in the groove when the plate and laminae may be
withdrawn from the casting.
My invention is susceptible of considerable variation in detail, for example, in
place of a flange a series of lugs may be provided on the casting, and in lieu of
cutting a groove in the casting for the reception of the fastening ring a series of
shoulders may be formed thereon against which said ring is held by the annular
plate.
My invention is applicable not only to those cores intended for use in the rotating
parts of electrical machines in which the laminae are slipped over and outside the
casting or foundation, but is equally well adapted to and is intended to be used
in connection with cores, such for example as those of the stationary members of

page_text: induction motors in which the laminae are arranged within the casting, and
enclosed by a cylindrical inner periphery of the same.
Dated this 12th day of July 1897.
W. P. THOMPSON & Co.,
Patent Agents for the Applicant, 322, High Holborn, London, W.C.
Improvement in Fastening Means for Core Plates of Electrical
Machines.
I, EDWIN EMERSON NOLAN, of 517, Center Street, Wilkinsburg, in the County
of Allegheny, State of Pennsylvania, one of the United States of North America,
Mechanical Engineer, 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: --
My invention relates to the cores of electrical machines, and has for its object
to provide an improved means for securing in position the laminae or core plates
forming said cores.
According to my invention the casting on or to which the laminae are to be
secured is provided with a flange at or near one end, and at the other end has a
circumferential groove which forms a shoulder. After the laminae have been
assembled in position on or in the core an annular plate similar to but thicker
than the laminae is placed in position and temporarily secured so that the laminae
are clamped between it and the end flange of the casting. After the plate has
been pushed sufficiently far towards the flange to expose the circumferential
groove a spring ring or segments forming a ring are placed in the said groove so
as to project outside of the same and in the path of the annular plate, and to
prevent the same from moving back and releasing the laminae. In order to
prevent accidental displacement of the fastening ring the annular plate is prefer-
ably provided with a shoulder on its outside which engages with the exterior of
said ring and holds it in the circumferential groove in the casting.
In the accompanying drawing
Figure 1 is a longitudinal, sectional view in perspective of an armature core of
a generator or motor, constructed according to my invention.
Figure 2 is a perspective view of the fastening ring.
Figure 3 is a detail sectional view on an enlarged scale of the fastening ring and
the adjacent co-operating parts.
1 is a casting having a cylindrical outer periphery for supporting the core plates
or laminae. At or near one end of said casting is a laterally projecting circum-
ferential flange 2 and at or near the other end of the same is a circumferential
groove 3 forming a shoulder 4. 5 is an annular plate the inner periphery of which
is substantially the same as the outer periphery of the core 1. 8 are the laminae
which are provided with slots or grooves for the reception of conductors as is usual.
in machines of this character, and these laminae are clamped rigidly between the
flange 2 and the annular plate 5. The said plate 5 is preferably provided with a
shoulder 11, as indicated. 12 is a spring metal ring which is partially located in
groove 3, but extends outside the same and against the shoulder 11 on the plate 5.
In order to assemble the parts in the position shewn in Figure 1, the laminae
constituting the outer portion of the core are first built up upon the casting 1, and
the annular plate 5 is then placed in position and pressed inward against the plates
by any suitable mechanism to a point slightly beyond that shown in the drawing.
The ring 12 is then sprung into place in groove 3, when the plate 5 is released

page_text: and springs outward against the said ring. The parts are thus rigidly clamped in
position and by reason of the shoulder 11 there is no possibility of the fastening ring 12
being thrown out of its normal position by centrifugal force due to rotation of the
armature. It will be readily seen that if it is desired to separate the parts of the
core, it will be merely necessary to subject the plate 5 and laminae 6 to sufficient
pressure to permit the ring 12 to pass the shoulder 11, when it may be sprung out
of the groove, 4.
While I have shown my invention as applied to a core having a cylindrical outer
periphery and designed to rotate, I desire to be understood that it is equally well
adapted to and is intended to be used in connection with cores, such, for example,
as those of the stationary members of induction motors, in which the laminac are
arranged upon a cylindrical inner periphery, such construction being obviously
a mere reversal of that shown herein and above described.
It will also be understood that my invention is not limited to the construction in
which a single circumferential flange 3 is employed, since a plurality of projecting
lugs or flanges would be equivalent in operation, although perhaps not so advan-
tageous in construction as the form shown. It will also be understood that the
shoulder 4 formed by the groove 3 in the casting 1 might be replaced by a plurality
of shoulders and formed otherwise than by cutting a groove in the core, if it
should be found desirable to do so. A plurality of sections or segments might also
be employed in lieu of the single ring 12, if desired.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be. performed, I declare that what I
claim is:-
1. For an electrical machine a core composed of laminæ maintained in position
on or in a supporting casting by means of an annular plate which presses the
laminae against a flange or lugs at one end of the casting, and which is secured by
means of a ring or segments of a ring located partially in a circumferential groove
provided in the casting, the projecting portion of the ring or segments bearing
against the outer side of the annular plate.
2. The modification of my invention wherein the annular plate is provided with
a shoulder on its outer side adapted to surround the fastening ring or segments
substantially as described.
3. For electrical machines laminated cores constructed substantially as described.
A 1808
W. P. THOMPSON & Co.,
Of London, Liverpool, Manchester and Birmingham,
Patent Agents for the Applicant.