IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES
Year: 1883

page_text: LETTERS PATENT to Henry Harris Lake of the firm of Haseltine Lake & Co.,
(f
Patent Agents, Southampton Buildings, London for an Invention of
'IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES" communicated to him from
abroad by George Washington Fuller of Norwich, Connecticut, United States
of America
COMPLETE SPECIFICATION filed by the said Henry Harris Lake at the
Office of the Commissioners of Patents on the 29th August 1883.
HENRY HARRIS LAKE, of the firm of Haseltine Lake & Co, Patent Agents,
Southampton Buildings, London "IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES"
communicated to me from abroad by George Washington Fuller, of Norwich,
Connecticut, United States of America
This Invention relates to dynamo-electric machines, and has for its primary
object to simplify the construction of that class of dynamo-electric machines in
which the induction coils traverse longitudinally the interior and exterior surfaces
of a hollow cylindrical core. I accomplish this result by constructing such a core
of one or more spirals, which can be inserted, by screwing, into induction-coils
previously wound in the form of oblong links.
When the core is composed of a single spiral, I employ a comparatively thin
ribbon, the sides of which are spirally imposed. In inserting such a spiral into
such coils the adjoining convolutions are capable of being sprung apart sufficiently
to allow the ends of the coils to pass between the convolutions. When two or
more spirals are employed, their convolutions are respectively interplaced, for
example, when two spirals are employed, the pitch of each spiral is regulated with
reference to preserving sufficient space between these convolutions to adinit the
convolutions of a similar spiral, and such space may be of sufficient width to allow
the passage through it of the ends of the coils in the act of inserting the spirals
into the coils. By supporting the spiral or spirals of which the core is composed,
upon, or by means of, devices composed of non-conducting materials, so that there
is no outside electrical connection of the terminals of a spiral with each other, I am
enabled to avoid the presence in the core of a complete circle of metal, or closed
electrical circuit in which currents of electricity can be established by induction.
At the same time by using iron, either wrought or cast, as the material for the
spirals, I am enabled to have a practically closed magnetic circuit.
This invention is applicable to dynamo-electric machines of various types as well
to those having annular armature cores as to those having armatures the cores of
which are cylindrical or spherical in form. The mechanical advantages possessed
I Drier A71

page_text: by the spiral, core are of considerable economic importance especially in the case of
an annular or hollow cylindrical core which is to be longitudinally traversed
internally and externally by induction-coils. Ordinarily such coils are applied by
winding the wire of which they are composed upon the core itself, which is a
laborious, tedious, and expensive, operation. In constructing coils according to
this invention the said coils may be wound upon a lathe into suitably formed links
which is a much easier and more economical method of winding them, and the
spirals composing the core may be successively inserted through these links by
screwing.
In the accompanying drawing
Figure 1 is an end elevation, of a hollow cylindrical armature showing the coils
in place, and one of the star-shaped heads by means of which the core is
supported upon the armature-shaft.
Figure 2 is a longitudinal section on the line ax Figure 1.
Figure 3 is a side elevation of the two spirals, showing one spiral-fully inserted'
through one of the induction-coils, and the other partially inserted.
Figure 4 is a perspective of one of the segments, which have the same
curve as the spiral and are interposed between the ends of the core and the ends
of the induction coils respectively, and are fastened to the arms of the star-shaped
heads by which the core is supported.
The drawing represents an arinature of the class in which the convolutions of each
of the induction-coils respectively traverse in a longitudinal direction both the
internal and external surfaces of the hollow cylinder which constitutes the
armature-core.
The induction-coils are symmetrically arranged upon the hollow cylinder, and
are thus adapted to be rotated between the curved faces of the field.magnets of a
dynamo-electric machine.
I have not deemed it necessary to shew any mode of connecting the coils with
each other or to shew any of the parts of a dynamo-electric machino excepting the
armature, as the mode of employing induction-coils upon cylindrical armatures in
dynaino-electric machines is perfectly well-known.
In the machine shown in the drawing, the usual armature-shaft A is inserted
through the hubs B of the, star-shaped heads B which are clamped in position by
means of the bolts b.extending from one head to the other and provided at their
opposite ends with the nuts b and 6. These bolts are inserted in holes through
the radial arms B' of the heads. Near the ends these arms are provided with
the laterally-projecting fingers B³ which afford the bearings for the interior surface
of the hollow cylindrical core and which are provided with facings of insulating
material upon which the concave surfaces of the spirals C C¹ bear.
The two spirals CO have the same axis, and the same pitch. Their convolu-
tions, which as shewn are interplaced, are prevented from contact with each other
by means of the tablets of insulating, material c which are inserted in those parts
of the spaces between the convolutions which are in radial alignment witli the
clamping bolts b.
The two spirals Cand C, when their convolutions are interplaced, form a hollow
cylinder, which is centralized by the bearing of its internal surface upon the facings
of insulating material laid upon the projecting fingers B. This cylinder is stayed
in position longitudinally by two rings D and D', each composed of short segments d
curved upon the same radius as the spirals and of such thickness that they can be
interposed between the end of the cylinder and the ends of the induction-coils.
Tlie segments d are fastened to the ends of the radial arms B by the screw d!.
Strips of insulating material are interposed between the ends of the cylindrical
core and the rings D D' respectively.
The induction-coils E are wound on a lathe in the form of flattened links with
straight parallel sides and the spirals are successively inserted through these links.
by a screw-like motion. The pitch of the spirals is such that the space between
any two of the convolutions is large enough to allow the passage of the end erōf a

page_text: coil. One of the spirals C is first fully inserted through all the coils, and there is.
then room for the similar insertion of the second spiral Cl. The segments d
composing the rings D D¹ are then inserted between the ends of the coils and the
ends of the core, and the coils are symmetrically grouped around the perimeter of
the hollow cylinder, leaving at each end six spaces for the arms B2 and fingers B³.
of the heads respectively. The tablets of insulating material, having been placed
between the convolutions the bolts bare inserted and the heads B¹ and the spirals
are then clamped together by the application of the nuts 6¹ and b².
The symmetrical arrangement of the circle of induction-coils E is effected by
the spacing-blocks E¹, which are deposited in the spaces between the external
portions of the coils, and are held in position by the clamping bands E2 E2 or by
wrappings of fine wire which surround the armature, as shewn in the drawing.
The hubs B of the heads B¹ are fixed upon the shaft A by means of the keys A¹
or otherwise, so that when the shaft revolves it carries with it the spirals which
constitute the core of the armature upon which the armature-coils are supported
The armature is then appropriately arranged in a dynamo electric machine, and
the coils are suitably connected in any desired manner.
In forming the spirals which constitute the core, I preferably prepare a hollow
cylinder of soft iron, and mount it in a lathe; having turned it to the required
diameter, I then cut it into two spirals of like pitch by the use of a double
pointed chaser having the required lead.
It will, however, be understood that such spirals can be made by bending rods
or wires of soft iron into the required form.
Having thus fully described the said invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim.
First. In a dynamo-electric machine, a hollow cylindrical armature, the core of
which is composed of one or more spirals, in combination with induction-coils the
convolutions of each of which traverse longitudinally the internal and external
surfaces of the cylinders composed of the said spiral or spirals, and means for
supporting the said cylinder and induction-coils upon the armature shaft.
Second. A hollow cylindrical armature-core composed of iron spirals of like
diameter and pitch suitably supported upon a rotating shaft but insulated there-
from, and having their convolutions respectively insulated from each other for the
purpose of preventing the presence, in the core, of a continuous metallic circuit, in
which currents of electricity can be established by induction when the said core is
provided with induction-coils and employed as an armature in a dynamo-electric
machine.
Third. A hollow cylindrical armature-core composed of one or more spirals, in
combination with the star-shaped heads B' affixed to the armature-shaft A and
provided with the laterally projecting fingers B³ for the purpose of centralizing the
said core relatively to the armature-shaft.
Fourth. A hollow cylindrical armature-core composed of one or more spirals,
substantially as set forth, and the rings D and D' each composed of the segments d
secured to the radial arms B of the heads B' and means for longitudinally clamping
the heads and core together, substantially as, and for the purpose, specified.
In witness whereof I the said Henry Harris Lake have hereunto set my hand
and seal this Twenty ninth day of August in the year of our Lord One thousand
eight hundred and eighty three