Improvements in Armatures for Dynamo Electric Generators and of No. 1742, Electric Motors.
Year: 1891

page_text: Date of Application, 1st Sept., 1891-Accepted, 31st Oct., 1891
COMPLIMIE DELTA
Improvements in Armatures for Dynamo Electric Generators and
of No. 1742,
Electric Motors.
A communication from abroad by JAMES FRANCIS MCLAUGHLIN,
Diamond Street, Philadelphia, in the County of Philadelphia and State of
Pennsylvania, United States of America, Electrician.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.ME., of the Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and -6, Bank Street
Manchester, both in the County of Lancaster and 323 High Holborn in the
County of Middlesex, Civil 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 has reference to improvements in armatures for electric motors,
and generators, its object being to produce an electric motor or generator, the
armature coils of which are each separately wound, without requiring the handling
of the armature as a whole; and these coils are so assembled and connected as to
make it possible to remove any one of these coils, for inspection or repair, without
dismantling the whole armature. It is consequently possible to replace defective
coil by another new coil, thus facilitating and cheapening the repair of armatures.
An additional feature of the invention is that the armature coils are on all-sides
5 protected against mechanical injury, being embedded in the armature body near
the circumference thereof, and so close to that circumference, that the inductive
influence of the field magnets is exerted upon the coils to best advantage.
All this will more fully appear from the following detailed description in which
reference is made to the accompanying drawings, in which is illustrated one general
form which the invention may assume.
In these drawings,
Figure 1, is an end view of the improved armature, partly in section, and with
portions removed;
Figure 2, is a perspective view of a portion of a skeleton core of an armature
coil-section.
Figure 3 represents an axial section of the armature.
Figure 4, a section at right angles to the axle of a portion of the armature.
Figure 5, is an end view of the connections of the armature coils with each other,
and with the commutator, the coils being shown in diagram.
Figure 6 is a perspective view of a combined armature coil connector and
commutator segment, and
Figure 7 is a central section of the construction shown in Figure 5 with parts
omitted for the sake of simplicity.
Like numerals of reference indicate like parts all through the drawing.
The body of the armature is composed of iron lamina 1, which are circular
disks cut from soft sheet-iron, with spaces 2, cut out near the centre, both for
the purpose of reducing the weight and for affording ventilating channels for
the armature. In addition thereto, cach lamina has a circular row of segmental
perforations 3, 3 near its outer edge; these perforations are small, as compared
with the size of each disk, and they, therefore, very nearly approach in shape,
a quadrilateral. Each iron disk 1 has a central perforation adapting it to be
mounted upon the armature shaft 4 and to be keyed thereto as will appear
further on.
In building up the body of the armature, there is used a series of
lamina of insulating material, such as paper, hard rubber, vulcanized fibre,
wood or mica, shaped exactly like the iron disks and préferably cut by the same

page_text: die.
These laminae of insulating material are indicated in Figure 3 by the
dark shading between the iron disks 1, and they are assembled upon the armature
shaft as follows:
There is first keyed to that shaft. a metallic, head 5 which has the size of the iron
disks, and is, in fact itself a solid iron disk, with a hub 6 formed in the centre.
This head is keyed to the shaft by a key 7, and the insulating laminæ alternating
with the iron lamina are then slipped upon the shaft in such positions relative to
each other, that the perforations 2 and 3 of one lamina coincide with the like
perforations in the other lamina, so that when the required number of lamina
is placed upon the shaft the perforations 2 and 3 will form channels extending
parallel with each other, and to the shaft, as will be readily understood. After
the last insulating lamina there is placed upon the shaft a second metal head 8
constructed similarly to the head 5, except that it is provided near its circumference
with a series of segmental perforations 3', corresponding in size and position to
the like perforations in the metallic and insulating lamine. This head 8 is
forced down upon the armature body thus formed, by a nut 9, screwed upon the
shaft 4.
The channels formed by the segmental or nearly quadrangular perforations 3, 31,
are designed to receive the armature coils with their cores, and these coils and
cores are constructed in the manner more particularly indicated in Figures 2
and 4. For each coil there is a bobbin, built up of two trough-shaped pieces 10,
of sheet iron, the bottoms of which are riveted together and to a number of iron
strips 11, by rivets 12, or in any other suitable manner. The bottoms of the two
troughs, together with the interposed iron strips 11, constitute the cores proper of
the armature coils, which are wound upon these cores, between the flanges, which
are constituted by the side walls of the troughs. Each coil 13, of insulated wire
together with the iron bobbin, upon which it is wound, constitutes an element of
the improved armature. The size of each bobbin is such, that it will snugly fit
into one of the channels formed by the perforations 3, 31, filling that channel
from end to end, that is to say, from the inner face of the head 5, to the outer
face of head 8. In order to keep the armature coils within their channel housings,
sectoral coverings 14 are applied upon the outer face of the head 8, which may be
made of any material, but which are preferably made of iron. These coverings
are screwed down upon the head 8, by screws 15, and if one of these sectors is
removed, the ends of a number of armature coils are exposed, and then the coils
may be withdrawn from their housings for inspection and repair, or for exchange
with others, if they should happen to be burned out, or otherwise injured. It will
be seen, however, that any other injury to the armature coils, than that caused by
over-heating, is practically impossible.
The terminals of the armature coils must of course be connected with each
other, and with the commutator, and this may be done in any desired manner. Two
practical means of making these connections are indicated, but the invention
is not limited to these means, although they form a part of this Specification.
In Figure 1, the armature coils are represented as being connected with each
other by wire loops 16, and with the commutator by branch wires 17; but this is
only a diagrammatic representation, while in Figures 3 and 4 a practical means is
indicated.
On the outer face of the head 8, there is formed an annular recess '18, which runs
into the inner edges of the segmental perforations formed in said head ; and
corresponding to the webs 19,.which separate these perforations, there are also
formed upon the outer face of the head 8, radial recesses 20 communicating with
the annular recess 18.
At the junctions of the annular recess 18, with the radial recesses 20, are placed
the connectors 21, which are small T-shaped metal blocks provided with means
for clamping a conductor to each of the three ends. These connectors may have
an axial bore through the stem of the T, into which the wires to be connected are
passed, and are clamped therein by means of clamp screws 22. Such connectors

page_text: are well known in the art and may be used with great advantage for connecting
the terminals of adjacent armature coils together and with the commutator. This
is so well illustrated in Figure 4, that further description seems to be unnecessary,
it being understood that the wires 23, which are placed in the radial channels 20,
are connected each with a segment of the commutator, the commutator, itself, is
not shown in the drawing, since it may be of ordinary construction.
Another practical means for connecting the armature coils together, and with
the commutator, is indicated in Figures 5, 6 and 7.
There is a ring 24 of insulating material which is provided with a number of
lugs 25, and this ring is of such size that, when placed upon the outer face of the
head 8, the ends of the lugs will clear the inner edges of the segmental perfora-
tions 31. This ring is secured to the head 8, by screws 26, passing through the
lugs into the face of the head, and washers 27 are interposed between the lugs and
the head 8, so as to leave a space between the ring 24, and the head, for a purpose
which will presently appear.
Upon the ring 24, are secured binding posts 28, each corresponding to a junction
of two adjacent armature coil sections, and it has been found practicable to rivet
these binding posts to the ring 24, as indicated at 29, in Figure 7. The washers 27
prevent contact of the rivet ends with the metallic head 8.
There is a transverse hole, 30, in each binding post, and a binding screw 31,
passing axially into the post, clamps the wires which constitute the terminals of
two adjacent armature coil sections. Before this screw is inserted, there is placed
upon the upper end of the binding post, the angular copper piece 32, which is
formed at one end with an eye 33, and at the other end with a commutator
segment 34.
A single screw, therefore, connects the terminals of two adjacent armature coil
sections with a commutator segment. It will be understood that when this con-
struction is adopted the recesses 18 and 20, in the outer face of the head 8, are or
may be omitted.
-
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated
to me by my foreign correspondent, I declare that what I claim is :-
1. An armature for electric motors and generators, comprising an iron body
having a circular series of channels near its outer edge, and an armature coil section
housed in each chanuel, substantially as described.
2. An armature for electric motors and generators, comprising a laminated iron
body having a circular series of channels near its outer edge, and an armature coil
section housed in each channel, substantially as described.
3. An armature for electric motors and generators comprising a cylindrical
laminated iron body mounted upon a rotary shaft and having a circular series of
segmental channels near the periphery and parallel to the shaft, and an armature
coil section housed in each channel, substantially as described.
4. An armature for electric motors and generators comprising a laminated iron
body with a series of perforations or channels near its edge, and a series of
armature coil sections each comprising a laminated core carrying a coil of wire,
and housed in the perforations or channels of the body, substantially as described.
5. An armature for electric motors and generators, comprising a series of alter-
nating iron and insulating disk lamine having a series of perforations formed near
their edge and constituting channels for the reception and housing of armature coil
sections, and heads at each end of the series of laminæ clamping the latter
together, substantially as described.
6. An armature for electric motors or generators, comprising an iron body having
a series of channels near its outer edge, armature coil sections housed in the said
channels, and a sectional face place covering one end of the armature body for
retaining the coil sections within the channels, substantially as described.
7. In an armature for electric motors and generators, the combination of a series

page_text: of coil sections removably housed within a laminated iron body, with couplings for
connecting and disconnecting the terminals of adjacent coils with each other and
with the commutator, substantially as described.
8. In an armature for electric motors and generators, the combination, with a
series of removable coil sections, and couplings, for connecting and disconnecting
the terminals of adjacent coils with each other, of commutator segments each pro-
vided with an angular extension terminating in an eye for connection with the
couplings of the coil sections, substantially as described.
Dated this 31st day of August 1891.
WM. P. THOMPSON & Co.,
Agents for the Applicant.