Improvements in the Construction of Armatures for Dynamo Electric Machines.
Year: 1884

page_text: Improvements in the Construction of Armatures for Dynamo
Electric Machines.
We, FRANK WYNNE of 4, Carteret Street, Westminster in the County of
Middlesex, Engineer and ROBERT PERCY SELLON of Surbiton in the County of
Surrey Electrical Engineer (address) Claremont Villas, Surbiton, S.W. do hereby
declare the nature of our invention for IMPROVEMENTS IN THE CONSTRUCTION OF
ARMATURES FOR DYNAMO ELECTRIC MACHINES, to be as follows:-
Our Improvements consist chiefly in novel methods of building up and
constructing armatures of dynamo electric machines, mainly of or with thin iron
sheet or wire.
In constructing an armature core, we take a metal ring, usually of cast or wrot
iron, which we prefer to speak of as the foundation ring, which we attach in some
convenient manner to the driving shaft of the machine. On this cast or wrot iron
ring, we wind strip or hoop iron spirally so as to form a short spiral cylinder
which we prefer to refer to hereinafter as a "spiral cylinder" of the depth of the
ring, on which it is wound or thereabouts and to any convenient diameter.
We sometimes divide the spiral cylinder into shorter spiral cylinders, by dividing
up the strip or using a larger number of narrower strips.
We wind these strips either plain or varnished or where convenient in com-
bination with strips of paper, linen, cloth or other convenient insulators, wound
between the folds of the iron strip or strips and so as to separate such layers of
the iron strip.
Such a spiral cylinder may be made up of a single spiral of iron strip or of
several, as we sometimes wind the said spiral cylinder or cylinders or any of them
with a double, treble or other convenient multiple spiral of iron strip. This we
effect in the case of the double spiral by starting our winding of the strip in the
usual manner, as if we were winding a single spiral and then at any suitable place
starting another strip, and so on, with three or more, and it is often convenient,
when using more than one strip to commence winding these from equidistant.
points round the foundation ring. One advantage of this winding in multiple.
strip is, that if we have to wind any one spiral in several lengths, instead of one,
D .
17

page_text: a
single length, we can arrange that this break in continuity in any one spiral takes
place at a point where the length of strip, with which the following or overlapping
spiral is being wound, is still conveniently long to sufficiently bind it. This may
apply to all spirals, which may thus be made up of such lengths, as are suitable, to
put it more shortly, the points of discontinuity in one strip may break joint with
the points of discontinuity in the other strips.
When wound to a sufficient diameter, we stop the end or ends by rivets or
screws extending through any convenient number of the layers, and, if necessary,
through the foundation ring or by the method hereinafter described or any other
suitable method, and we sometimes hold the cylinder, so built up in place by a
circle of iron or tire, which may be shrunk or forced on the spiral cylinder or
cylinders and when using this tire it is not always necessary to stop the ends of
the strip by rivets or screws.
In cases where we make up our core of more than one parallel spiral cylinder
wound either in single or multiple strip as hereinbefore described, we employ a
device, which we have found extremely efficient for securing the shape of our
cylinder, both holding it and stiffening it and which device also enables us to effect
better ventilation, where required, for the core. This device consists of one or
more flat rings or discs preferably of iron and which disc we prefer to speak of as
a "stiffening ring" which is sometimes suitably corrugated.
This stiffening ring we usually form from a disc of sheet iron and the internal
diameter of the "stiffening ring" is cut to the outside diameter of the foundation
ring, on which it fits. Round the circumference of this ring, which for this
purpose is left larger than that of the cylinders, we cut notches or slit the
circumference conveniently by more or less radial slits, leaving what we may term
'flaps" between them.
«
Where we use a single stiffening ring and two cylinders we find it convenient
to bend the alternate flaps between the slits or notches respectively over one
cylinder and the other as shewn in Fig. 1 of the drawings accompanying this
provisional specification. When using two such stiffening rings we cau bind the
flaps of one disc over one cylinder and those of the other disc over the other
cylinder and we may also so notch them out, that they may interlace each other
and their flaps alternately or otherwise fold down over each spiral cylinder. The
same construction may be repeated if more than two cylinders are used side by
side to compose the core and the ends of the spiral or spirals, instead of being
stopped" by rivets or bolts may conveniently be interlaced into a convenient
number of "flaps."
"
The better ventilation of the core, where required, is obtained by drilling holes
through the foundation ring so as to allow of the entrance of air on one or both
sides of the supporting stiffening disc and these may be corrugated in a suitable
form, so as to allow more ready circulation of air.
•
An important part of our Invention relates to the method by which we secure
ventilation between the layers of the strip and is applicable both to spiral cylinders
built up of single spiral and also to those with multiple spiral. In carrying out
this portion of our Invention we "whip" or serve one or more spirals with a slip
or string of suitable material, in some cases, we have used hemp string for this
purpose, in other cases fat ribband or round wire and in whipping or serving the
strip in this way, we do it in such a convenient open spiral as to leave opening
for the air to pass between the layers of strip iron. A method which we have
found a very suitable one has been to wind a cylinder from a double spiral of strip
iron and to whip or serve only one of the spirals in this way and this ensures
great regularity in the openings between the strip and where two cylinders of this
served iron slab are used in connection with the stiffening disc for the core of an
armature ring, a very thorough ventilation is secured on the rotation of the
armature, by the air being drawn in between the spirals and out through the
centre between the stiffening disc and spiral cylinders,

page_text: We sometimes form pockets or supports for the wire bobbins of armature rings,
by the use of iron wire flattened or band iron, which we bend and shape preferably
in an undulatory or corrugated form (as shewn in Figs. 2. 3. 4, accompanying this
provisional Specification, where the depth of the undulations or corrugations is
made preferably about that of the depth of the wire bobbins, where occasionally
the iron wire or band is carried straight without any corrugations or undulations
whereby a pocket is formed for the reception of the wire bobbins, as shewn in
Fig. 2, accompanying this provisional specification. These iron corrugations may
form either an endless ring encircling the exterior or sides of an armature core,
which may be a continuation of the band iron of the core, or they may be in any
number of pieces, each piece forming a segment of the circumference of the
armature core: we may further insulate these pieces from the armature core, if
hecessary. This continuous ring or these separate portions are held down by the
wire bobbins and serve the double purpose of acting as supports for the wire
bobbins and securing a more perfect magnetisation of the armature core.
יהנות
DAIL
1000
FRANK WYNNE.
R. PERCY SELLON.

page_text: COMPLETE SPECIFICATION.
Improvements in the Construction of Armatures for Dynamo
Electric Machines.
•
We, FRANK WYNNE of 4, Carteret Street, Westminster in the County of
Middlesex, Engineer and ROBERT PERCY SELLON of Claremont Villas, Surbiton
in the County of Surrey, Electrical Engineer do hereby declare the nature of our
invention for IMPROVEMENTS IN THE CONSTRUCTION OF ARMATURES FOR DYNAMO
ELECTRIC MACHINES and in what manner the same is to be perforined, to be
particularly described and ascertained in and by the following statement:--
Our Improvements consist chiefly in novel methods of building up and con-
structing armatures of dynamo electric machines. In constructing our armature
cores we take a metal ring usually of cast or wrought iron, which we hereinafter
refer to as the "foundation ring" and which we attach in some convenient manner
to the driving shaft of the machine. On this "foundation ring" we wind strip or
hoop iron spirally, so as to form a spiral cylinder, which we hereinafter refer to as
a "spiral cylinder," preferably of the width of the ring on which it is wound or
thereabouts and to any convenient diameter; or we sometimes divide the spiral
cylinder into shorter spiral cylinders, by dividing up the strips or using a larger
number of narrower strips. These strips are wound either plain or varnished, or in
combination with strips of linen, paper, or other convenient material, wound between
the folds of the iron strip or strips, and so as to separate each layer of the iron
strip. Such a spiral cylinder may be made up of a single spiral of iron strip or
of several spirals, wound with a double, treble, or other convenient multiple spiral
of iron strip.
When wound to a suflicient diameter, we stop the end or ends of the iron strip
by rivets or screws extending through any convenient number of the layers, or, if
necessary, through the foundation ring also, or by the method hereinafter
described or in any other convenient and well known manner.
In cases where we construct an armature core of more than one parallel spiral
cylinder, we may employ a device, which we have found extremely efficient for
securing and retaining the shape of our cylinder, both holding and stiffening it,
and perinitting of thorough ventilation, where required, of the core. This device
consists of one or more flat rings or discs, preferably of iron, and which may in
some cases be suitably corrugated preferably in a radial direction. This disc, we
usually form from a sheet of iron; the internal diameter of such disc being cut to
the outside diameter of the foundation ring, on which it fits. This disc or discs
may, if required, be conveniently joined to the "foundation ring" by cutting out
or notching" the internal periphery of the ring, and bending the portions so
"notched" at right angles to the plane of the disc, so that they may be rivetted or
otherwise held to the external periphery of the "foundation ring." The external
periphery is also "notched" or slit, leaving flaps; these flaps or parts left between
"

page_text: core.
the notches or slots are bent over at right angles to the plane of the disc, so as to
hold the spirals of iron strip on one or both sides of it. This construction applies
to all armature cores whatever are the number of spiral cylinders, that compose the
The aforesaid discs may be corrugated radially, and a free passage for air is
thus opened up from the interior of the core to the external periphery of the ring.
One part of our Invention relates to the method by which we secure ventilation
between the layers of the strip. or strips, when wound into spiral cylinders: we
effect this by "whipping" or serving the iron strip in the process of winding with
some suitable material such as hemp, string, tape or paper or even thin iron strip,
this material being served around the strip in such an open spiral as to leave
passages for the air to pass between the layers of strip.
In some cases, where it is impracticable to use very long lengths of band iron strip,
we wind our armature cores out of two or more shorter lengths of such strips so as
to form a double, treble or other convenient multiple spiral. In this case we
preferably whip or serve the insulating material around every alternate strip wound
upon the armature core.
A further portion of our Invention consists in a method of constructing pockets
or supports for the wire bobbins of armature rings: these we preferably construct
out of layers of band iron bent or shaped in an undulatory or corrugated form :
the depth of the undulations is made, preferably, about equal to that of the wire
bobbin, while at the points where the wire bobbins are wound upon the core, the
band iron strips pass beneath them, so that a pocket is forined, for the reception of
the wire bobbins, whereby they receive support upon the outer diameter of the
armature ring and these projections or supports at the same time afford an easier
path for the lines of force from the magnets into the armature cores.
In order to make our Invention more clear we will now describe it by reference
to the accompanying drawings, in which similar letters represent similar parts.
In Figs. I. II. & III A shews the foundation ring, which is fastened in any
suitable manner to the driving shaft; l. shew two spiral cylinders of iron strip
wound upon the "foundation ring," between which the disc P is placed, this disc
is corrugated, and the internal periphery is bent over at right angles at the
point p and rigidly fixed to the "foundation ring" A by means of suitable screws
or rivets 8: the outer periphery is also slotted and bent over at the point p,
alternate flanges of the disc holding down the two spirals 7 & 1.
In Figs. II and IV the iron strip is shewn served with paper, tape, or other
convenient insulating material t. t, one of the spirals being here shewn in course of
winding. The corrugations of the disc P and the positions occupied by the bent
flanges p. p, holding down the iron strip, are here clearly shewn.
In Figs. II & III the projecting portions R. R R are also shewn, surrounding on
the outer periphery, the spiral cylinders & l, and forming a support for the wire
bobbins B.
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
(i.) For dynamo electric machines an armature core composed of one or more
spiral cylinders of band iron, each spiral cylinder being constructed of two or more
lengths of band irou.
(ii) An armature core formed as in Claim (i) and in which one or more of the
spirals is whipped or served with suitable material and in such a way as to leave
passages for ventilation between the turns of the serving.
(iii) In dynaino electric machines an armature constructed-as described, with
two or more spiral cylinders, in conjunction with a disc, placed between them as
& for the purpose substantially described.
(iv.) An armature core formed as in Claim (i) and in which one or more of the
spirals is whipped or served with suitable material, in such a way as to leave

page_text: passages for ventilation between the turns of the insulating material, in conjunction
with notched or slotted dise or discs placed between them & holding them, sub-
stantially as & for the purpose described.
(v.) In armature cores of dynamo electric machines the method of winding a
multiple spiral cylinder, one or more of the spirals being whipped or wound with
cord or strip, substantially as & for the purpose described.
(vi.) In dynamo electric machines an armature core having projections formed
out of layers of soft iron strips, and acting as supports for the bobbins, sub-
stantially as herein before described..