Improvements in Armatures for Electrical Apparatus such as Dynamos, Motors, and Transformers.
Year: 1890

page_text: Date of Application, 26th June, 1890
Complete Specification Left, 26th Mar., 1891-Accepted, 9th May, 1891
PROVISIONAL SPECIFICATION.
Improvements in Armatures for Electrical Apparatus such as
Dynamos, Motors, and Transformers.
I, WILLIAM HENRY CLARKE, of 6 Parsonage Square, Exchange Street,
Norwich, in the County of Norfolk, Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to improvements in armatures for electrical apparatus
such as dynamo electric machines, electro motors and transformers, in which
armatures of the drum or cylinder type are used. A drum armature as generally
constructed comprises a core built up of a number of sheet iron discs mounted or
threaded on a spindle and secured by nuts. The armature core is then wound over
lengthwise with coils of copper wire. As the whole of the iron core is covered by
the coils which overlap or cross one another at each end where the spindle passes
through the core, this kind of armature is very liable to get hot, when working
continuously for a lengthened period, as there is no provision for ventilating it.
This invention has for object to obviate this disadvantage in armatures of the
type mentioned. For this purpose the armature core is built up of thin sheet iron
discs each formed with a number of radial slots and mounted or threaded on a bush
of insulating material secured to the armature spindle. This bush has a spiral key-
way or featherway cut in it to form part of a screw thread, that may take about
two-thirds of a turn in the length of the armature. Each of the discs is provided
with a key or feather adapted to fit in the keyway or featherway in the bush. In
some cases the keyway or featherway may be made straight. To the spindle at one
end of the armature is keyed a plate that carries a number of flattened tubes equal
in number to that of the radial slots in the armature. These tubes enter the slots
in the armature core and pass through the plate terminating at their outer ends in
a specially shaped funnel or mouth-piece. The arrangement is such that when the
armature revolves, air is caught in the funnels and driven in a continuous stream
through the slots in the core of the armature, thus effecting thorough ventilation
thereof. At the end of the armature opposite to that at which the tubes are
located, openings are left between the wire coils for the escape of air passing
through the armature. The armature coils are wound in wide shallow grooves cut
in the plates forming the core. These grooves are parallel with the axis of the
armature, and may be cut after the core is built up.
Dated this 26th day of June 1890.
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Armatures for Electrical Apparatus such as
Dynamos, Motors, and Transformers.
I, WILLIAM HENRY Clarke, of 6 Parsonage Square, Exchange Street,
Norwich, in the County of Norfolk, 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:-
This invention relates to improvements in armatures for electrical apparatus such
as dynamo electric machines, electro-motors and transformers, in which armatures
of the drum or cylinder type are used. A drum armature as generally constructed

page_text: comprises a core built up of a number of sheet iron discs mounted or threaded on a
spindle and secured by nuts. The armature core is then wound over lengthwise
with coils of insulated copper wire. As the whole of the iron core is covered by
the coils which overlap or cross one another at each end where the spindle passes
through the core, this kind of armature is very liable to get hot, when working
continuously for a lengthened period, as there is no provision for ventilating it.
This invention has for its object to obviate this disadvantage in armatures of the
type mentioned.
For this purpose the armature core is built up of thin sheet iron discs each formed
with a number of radial slots and mounted or threaded on a bush of insulating
material secured to the armature spindle so that the slots in each disc come
together and form passages or spaces extending through the body of the armature
from one end to the other. The bush has formed therein a straight or spiral key-
way or feather-way, and each of the discs is provided with a key or feather adapted
to fit in the said key-way or feather-way. To the spindle at one end of the
armature is keyed a plate that carries a number of flattened tubes equal in number
to that of the radial slots or passages in the armature core. These tubes com-
municate with the slots or passages in the armature core and pass through the
plate, terminating at their outer ends in a specially shaped funnel or mouth-piece.
The arrangement is such that when the armature revolves, air is caught in the
funnel and driven in a continuous stream through the slots or passages in the
armature core, thus effecting thorough ventilation thereof. At the end of
the armature opposite to that at which the tubes are located, openings are left
between the wire coils for the escape of air passing through the armature. The
"armature coils are wound in wide shallow grooves cut in the plates forming the
*core. These grooves are parallel with the axis of the armature, and may be cut
after the core is built up.
In the accompanying drawing
Fig. 1 is a longitudinal elevation, partly in vertical central section, of an arma-
ture embodying my improvements.
Fig. 2 is a section thereof taken between two of the discs of which the armature
is composed.
Fig. 3 is an end view of Figure 2 looking towards the left.
Figs. 4 and 5 are elevations at right angles to each other; and
Fig. 6 is an end elevation of one of the air tubes with funnels or mouth piece.
Fig. 7 is a longitudinal elevation, partly in section, and
Fig. 8 is a transverse section, shewing a slightly modified construction.
A represents the spindle of the armature B which is built up of the plates C the
form of which is shewn more clearly in Figure 2 and which are provided with teeth
or cogs C¹ between which the wire is wound in the ordinary manner. Each of these
discs has formed therein four radial slots D arranged around the disc, the space
between each pair of adjacent slots being equal.
The discs are secured upon a bush E of insulating material which is provided
with a key-way or feather-way E¹ into which projections or feathers DI on the
discs are adapted to enter. The discs C are passed on to the bush E which is
keyed to the shaft A, and are securely clamped together between the collar A',
and the nut A² which works upon a screw-threaded portion of the spindle A, the
discs being so arranged that the corresponding slots D are in line with one another,
thereby forming the longitudinal passages B₁ in the armature B. These passages
have projecting into them at one extremity of the armature the tubes F which are
preferably of a flattened or rectangular form in transverse section and are secured
to the disc or plate G the mouth pieces H being secured on the other side thereof
and communicating with the tubes through apertures in the said disc.
In the rotation of the armature in the direction indicated by the arrow in Fig. 3
the mouth pieces H act as scoops and the air entering the same is caused to pass
through the pipes F and the longitudinal slots or passages B¹ thereby cooling the
armature in a very efficient manner.

page_text: In winding the armature wooden pieces are placed in the ends thereof, in the
positions which the tubes are to occupy, these wooden pieces corresponding with
the size and shape of the said tube, so that after winding, the said pieces can be
removed and the ends of the tubes inserted in the spaces thereby formed.
In the modification shewn in Figures 7 and 8, a series of apertures B² are
provided in the circumference of the armature, which communicate with the
passages B. In this case a portion of the air moving through the passages B₁
is discharged through the apertures B2 whereby over heating of the pole pieces of
the field magnets is prevented.
Although I have shewn the bush E as provided with a straight key-way or
feather-way E', I find it advantageous in some instances to make the said key-way
of slightly spiral form, preferably winding round the spindle to the extent of about
two-thirds of a turn in the length of the armature thereby giving a corresponding
spiral form to the passages B¹ in the armature.
It is obvious that the arrangement of each tube F and its mouth piece H may
be somewhat varied, and that the particular shape of the said mouth piece may be
modified without departing from the nature of my said invention.
Although the armature shewn in the drawings is provided with four passages B¹
the number of these passages may be varied or increased as may be found
desirable.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what I
claim is :-
1. An armature for electrical apparatus such as dynamos, motors, and trans-
formers, having within it a series of longitudinal passages in communication with
tubes provided with funnels or mouth picces adapted when the armature is rotated,
to cause air to flow through the said passages substantially as herein before described
for the purposes specified.
2. My improvements in armatures for electrical apparatus such as dynamos,
motors, and transformers, substantially as hereinbefore described with reference to
and shewn in Figures 1 to 6 inclusive of the drawings annexed or modified as shewn
in Figures 7 and 8.
Dahi noth 1
CML 1001
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.Č., Agent for the Applicant.