Improvements in Dynamo Machines.
Year: 1891

page_text: Date of Application, 24th Sept., 1891
Complete Specification Left, 23rd June, 1892-Accepted. 13th Aug., 1892
PROVISIONAL SPECIFICATION.
Improvements in Dynamo Machines.
We, ROBERT HAMMOND, Electrical Engineer, and CHARLES JAMES HALL,
Electrician, both of 117, Bishopsgate Street Within, in the City of London, do
hereby declare the nature of this invention to be as follows:-
This invention relates to dynamo machines of the alternating current type, and
to that class of machines in which a system of field magnets is caused to revolve,
while the armature is stationary. The conducting coils of the armature are com-
bined with laminated iron in the form of segments, which are arranged as a ring
surrounding the path of the field magnets. Each segment-with a conducting
coil-is adapted to be removed from the armature with great facility, so as to be
readily replaced by an interchangeable segment and coil, whenever a coil becomes
defective.
The
The field magnets are bolted to an iron ring so that their poles project outwardly
in a radial direction, in a well known manner. The ring is mounted upon
and turns with a shaft, working in bearings, in any convenient manner.
bearings are supported upon a suitable bed plate, which also carries the standing
armature, the latter being mounted centrally between the bearings and concentric
with the axis of the shaft. Suitable means are applied for driving the shaft.
The standing armature comprises the aforesaid laminated iron segments, the
conducting coils in which the current is induced by the field magnets, wooden
bearers or clamps between which the ends of the coils are clamped, open distance
blocks of iron, and side cheeks that serve as the framework of the armature.
The segments are built up of insulated iron plates and are formed with poles,
slightly projecting inwardly and they correspond in number to the several field
magnets. Each laminated segment is formed of a sufficient length to provide a com-
plete polar projection in its central part, and a half polar projection at each
end. Consequently, when bolted together in the form of a ring, a radial joint
exists in the centre of each alternate polar projection of a segment of the iron
core.
Each conducting coil is preferably formed of copper tape and arranged as a
winding around the central polar projection of each iron seginent, and is wound of
such a width as to occupy the sunken space between the said central projection and
the halves at the end of the segment. Consequently, a complete conducting coil is
combined with each complete iron segment; but there are ouly half the number of
conducting coils as of polar projections. This arrangement provides therefore
(when the necessary connections are undone) for the removal of a complete coil and
its core.
The ends of the conducting coils are clamped to, or between, wooden bearers,
which conform generally to the shape and position of the iron segments. The
wooden bearers are carried by the open distance blocks of iron which are formed
like the sides of a box, but without lid or bottom. A distance block-also con-
forming to the shape and position of each segment-is bolted to each face of a
segment by one or more bolts and nuts, the bolts passing through the several
laminations of the thickness of the core, serving to bind the core firmly to the
inner sides of the two open distance blocks. The outer sides of the two opposite
distance blocks are bolted to the side cheeks of annular form, which serve as
the framework of the armature; while the top and bottom wood bearers are
screwed together at convenient points to clamp each end of a conducting coil firmly
hetween them
.:

page_text: It will be seen from the above description that by taking out the required bolts
on each side cheek, a segmental core with its complete coil, attached bearers and
open distance blocks may be lifted out of the armature framework, and a similar
section interchangeably formed-substituted therefor with great facility. A
shoulder is formed on the inner face of the side cheeks to receive the open
distance blocks with attached segments and coil in their proper relative positions.
The pole pieces of the field magnet system are bolted to an iron ring as previously
mentioned, and two T headed bolts are usually employed for the purpose. The
head of each bolt projects somewhat on each side in the form of flanges, and as
eddy currents frequently heat the magnet poles on the edges leaving the armature
poles, laminated plates are preferably attached to the T headed bolts by a trans-
verse bolt or rivet passing through a flange of the T headed bolts and through the
several plates to hold altogether. The form of the laminated plates corresponds
with the projecting flanges of the T headed bolts, and the laminations may be
placed on each side of the magnet poles, to admit of the machine being run in either
direction.
Dated this 23rd day of September 1891.
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Dynamo Machines.
We, ROBERT HAMMOND, Electrical Engineer, and CHARLES JAMES HALL,
Electrician, both of 117 Bishopsgate Street Within, in the City of London, 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 dynamo machines of the alternating current type,
and to that class of machines in which a system of field magnets is caused to
revolve while the armature is kept stationary. The conducting coils of the
armature in which current is induced-are combined with laminated iron segments,
arranged as a ring surrounding the path of the field magnets. Each segment is
made complete with one conducting coil, and the two are so combined and
arranged that any segment with its coil may be rapidly removed from the
remainder of the armature to be as readily replaced by another combined
segment and coil, (made interchangeably) whenever a coil becomes defective in
working.
In the further description of this invention, reference is made to the accompanying
drawings in which
Fig. 1 is a face elevation of an improved dynamo machine on the right hand half
of the figure, while the left hand half is a section taken vertically. The upper
portion of the section shows the field magnets and ring in elevation and the
armature segments in their relative position thereto, but with their respective
windings omitted. The lower portion of the section represents the side cheeks
or framework of the armature with the iron distance blocks, and wooden bearers
or clamps, which carry the armature segments and their coils.
Fig. 2 is a longitudinal elevation of the machine, but with the field magnet and
armature systems in transverse vertical section.
Fig. 3 is also a transverse section of a part of the armature and field magnet, on
an enlarged scale; Fig. 4 is a plan of the same, and Fig. 5 a face elevation
thereof, showing one complete segment of the armature and two unwound poles of
the field magnet system. In addition, a completely wound pole of the field magnet
system is also shown in relative position to the armature segment, on the right hand

page_text: side of Fig. 5. A brass cap is shown in elevation upon this last named polc, and
the said cap is shown in plan in Fig. 6.
In these drawings, a is the bed plate of the machine arranged to carry three
bearings b, in which a shaft c is adapted to rotate when driven by the rope
pulley d secured to the said shaft.
Two perforated discs e are also keyed to
the shaft c, and between these discs the field magnets are bolted and revolve
with them. Surrounding the path of the field magnet system are the armature
segments formed with shallow inwardly projecting poles, coinciding in number
and position with the field magnet poles f. The segments 9 are built up of
laminated iron plates of a sufficient length to provide a complete polar projection
in its transverse central part, and a half polar transverse projection at each end.
Consequently, when bolted together in the form of a ring, a transverse radial
joint exists in the centre of each alternate polar projection of a segment of the iron
core.
Each armature conducting coil h, (in which the current is induced), is
preferably formed of copper tape and arranged as a winding around the central
polar projection of each segment g; and is wound of such a width as to occupy
the sunken space between the said central polar projection, and the half polar
projection at each end of the segment; as is shown in Fig. 5. Consequently a
complete conducting coil his combined with each complete iron segment, g, but
it is to be observed that there are only half the number of conducting coils h,
as of polar projections. This construction and arrangement provides, therefore
(when the necessary connections are undone), for the rapid removal of a complete
coil and its core or segment g.
The ends of each conducting coil h are clamped to or between wooden bearers i,
and j, (see Fig. 3); also arranged in segments to lift out with the coil h and its
segment g. The inner bearer i is made narrow to be clear of the revolving field
magnets, but the outer bearer j is wider to give good support to the coil h. Each
bearer is directly screwed to an iron distance block k, secured by a transverse
bolt 1, to opposite faces of each segment g. The outer faces of opposite distance
blocks k are slightly bevelled to fit against a correspondingly bevelled face of each
annular side cheek m, two of which constitute the framework of the standing
armature. Bolts n are used to connect the distance blocks k to the side cheeks mi,
and when these bolts are removed, and the coils h disconnected, the armature
segment with its coil may be at once removed; the operation being facilitated by
the tapering faces of k and m.
ول
In Fig. 4 the plan outline of an armature coil ---with its rounded ends-is
indicated by dotted lines; and in the central part of each end is shown in plan
terminal connections in porcelain cups p, carried by a central rib of the distance
block k. The connections are also shown in elevation by dotted lines in Fig. 5,
and they afford every facility for joining up and disconnecting contiguous coils when
required.
.>
In Fig. 5, part of a field magnet ring with two unwound poles f, fare shown in
their relative position when coinciding with the slightly projecting poles of one
of the armature segments g. The pole pieces may be bolted to the ring by
T headed bolts, and cut to avoid eddy currents, or the field magnet system may be
constructed in any known manner. Fig. 6 represents a brass cap (in plan) of two
pieces rivetted together, and it is shown in place upon the head of a wound pole
piece on the right hand side of Fig. 5, as previously mentioned.
It is to be observed that the distance blocks k coincide generally to the segmental
form of the armature segments, and that they have opposite sides of flanges and
ends or ribs connecting the said flanges. They are open on the outer or top side
and may be open at the bottom also, and the bearers i and jare secured either to
the said bottom (as shown in Fig 3) or to the said connecting ends or ribs.
Furthermore, instead of forming the armature segments g with one central polar
projection, and end polar projections each of one half the width of the central pole,
(as shown in Fig. 5), the segments g may have two complete polar projections

page_text: formed thereon with the same intervening sunk space for the coils as before, but
this which we regard as equivalent, is not so desirable as the arrangement shown
in Fig. 5, as the coil is protected by the polar projections on both sides from
damage when inserting or withdrawing a complete segment.
It is further to be observed that the construction of the field magnet system, as
shown more especially in Figs. 1, 2, 5, and 6, is described in the application for
Letters Patent dated 21 June 1892, No. 11617 in the name of Charles James Hall,
one of the parties hereto; and therefore we make no claim to any part of the said
field magnet system; but we may use any known system of revolving field magnets
suitable for use with our said improvements, as herein described and claimed, in a
manner well understood by electrical engineers and electricians.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
1. In a dynamo machine, the combination of a revolving system of field magnets
with a standing armature built up of laminated iron segments interchangeably
formed, each segment carrying a single conducting coil forming a winding about a
central projecting pole bounded by two similarly formed half poles at the respective
ends of the segment, segmental clamping bearers, a distance block on each face of
each segment, and side cheeks or frames adapted to carry the said armature,
substantially as and for the purpose herein described.
2. In a dynamo machine, a standing armature having in combination two com-
plete annular side cheeks or frames, two or more interchangeably formed iron
segments each having projecting poles, a single complete coil winding for each
segment, segmental bearers clamping the ends of a coil to each segment, and
distance blocks for supporting the said segments and bearers between the side
cheeks, substantially as and for the purpose described.
3. In a dynamo machine, an interchangeable laminated iron segment having a
polar projection in the centre of its length and a polar projection at each end
together equal in width to the central pole, intervening sunk spaces adapted to
receive a coil winding, substantially as and for the purpose herein described.
4. In a dynamo machine, a distance block of segmental.form with opposite sides
and connecting ribs or ends, open at the top or outer portion, and combined with
armature segments and side cheeks or frames, substantially as and for the purpose
herein described.
5. In a dynamo machine, the combination of an interchangeable laminated iron
segment with polar projections, segmental distance blocks bolted to opposite faces
of the said iron segment, clamping bearers secured to the said distance blocks
and removeable therewith, and a conducting coil occupying the intervening sunk
space between the said polar projections, substantially as and for the purpose herein
described.
6. In a dynamo machine, the combination of a standing armature composed of
two or more interchangeable laminated iron segments with polar projections, a
rotatable field magnet system having poles coinciding in number with the armature
poles and continuously wound armature coils, one half in number only of the field
magnets, adapted to approximately occupy the space between the said polar
projections; substantially as and for the purpose herein described.
Dated this 23rd day of June 1892.
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicants.