IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES
Year: 1885

page_text: I, THOMAS PARKER, of Elwell-Parker Limited, Commercial Road, Wolverhampton
in the County of Stafford, electrical engineer, do hereby declare the nature of my
invention for, IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES, to be as follows:-
The primary object of this invention is to increase the effeciency of dynamo-
electric machines by improvements in the arrangement of the magnets and of the
winding of the armatures.
I will first describe my improvements in the arrangements of the magnets.
According to the simplest form of such arrangement, a pair of magnets is
fixed on opposite sides of the centre of the machine, and the four poles of these
magnets are arranged at, preferably, equal intervals around the armature, and so as
to alternate as to polarity. In order to maintain the poles in their proper position
in relation to the armature, the two poles of one magnet are distanced apart with
suitable non-magnetic distance pieces, and the North pole of each magnet is held
to the South pole of the opposite magnet, respectively, by means of suitable non-
magnetic distance-pieces; and, if the pairs of magnets are arranged so that their
axis is horizontal, or approximately so, the lower pole of each, magnet is carried
from the bed of the machine upon suitable non-magnetic blocks. Whether the
axis of the magnets is horizontal or vertical the yoke of each pair may be carried
by the framing of the machine, or the magnets may themselves form the frame of
the machine.
Two (or even more) pairs of magnets may be used, if desired, and in such case
are arranged and fixed in an analogous manner to that already described for
one pair.
My improvements in winding the armature of a dynamo-electric machine are as
follows:-
The coils are wound in two divisions each, such divisions being at right angles
(or approximately so) to one another on the surface of the iron core of a drum
armature. One division of the second coil is laid on immediately within one of the
divisions of the first coil, and the other division of the second coil is laid on at a
distance of (approximately) 90 degrees from the first division of such coil, and so
on around the armature, the winding being continued for successive revclutions
around the armature until the whole surface of the armature is covered with coils.
These coils are connected so that the ending of one is brought to a commutator strip

page_text: with the beginning of the next coil, and so on until the whole of the coils are
connected into one continuous conductor.
This arrangement of winding is applicable also in the case of a "Gramme" ring
armature, by connecting each coil to a coil 90 degrees in advance, instead of
connecting each coil to an adjacent coil in the usual manner.
By the above-described method of winding the armature, the line of commutation
is changed from the neutral line of the two magnets to a line underneath the
magnets themselves, and therefore the current leaving the armature produces a
magnetic effect corresponding to that of the magnetic system of the machine, and
thus the advantage is gained of a permanent point of commutation or collection
independent of the quantity of the current collected, and sparking is thereby
avoided. The efficiency of the machine is increased by the action of the outgoing
current assisting the field rather than opposing it.
The method of winding the armature above-described is applicable for a four-pole
machine if the coils are wound at 45 degrees instead of 90, and so on for a greater
number of pairs of poles.
STEPHEN WATKINS,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Dynamo-electric Machines.
I, THOMAS PARKER, of Elwell-Parker Limited, of Commercial Road, Wolver-
hampton in the County of Stafford, electrical 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, reference
being had to the accompanying drawings and the letters of reference marked
thereon (that is to say):-
:-
The primary object of this invention is to increase the efficiency of dynamo-
electric machines by improvements in the arrangement of the magnets and of the
winding of the armatures.
I will first describe my improvements in the arrangement of the magnets.
Two magnets are fixed on opposite sides of the centre of the machine, and the
four poles of these magnets are arranged so as to alternate as to polarity and, pre-
ferably, at equal intervals around the armature, and in order to maintain the poles
in their proper position in relation to the armature the two poles of one magnet
are distanced apart with suitable non-magnetic distance-pieces, and the North pole
of each magnet is held to the South pole of the opposite magnet, respectively, by
means of suitable non-magnetic distance-pieces, and, if the magnets are arranged so

page_text: that their common axis is horizontal, or approximately so, the lower pole of each
magnet is carried from the bed of the machine upon suitable non-magnetic blocks,
and in this case the bed acts as the distance-piece between the lower poles of the
magnets, being insulated therefrom by the non-magnetic blocks.
The drawing on sheet 1 herewith illustrates a dynamo-electric machine con-
structed, according to this invention, with two magnets having their common axis
horizontal. Figure 1 is a plan of the machine, and figure 2 a vertical section on
line xx of figure 1. The same letters of reference occurring upon both of these
views indicate corresponding parts. A A¹ is one magnet and B B¹ the other
magnet. The poles A and B are of corresponding polarity (say North poles) and
the poles A¹ and B' are of the opposite polarity (say South poles.) The poles of
the magnets are supported from a bed H H by means of non-magnetic blocks
b b, etc. and the poles A A¹ are distanced apart by non-magnetic distance-pieces c c c,
and the poles B B¹ by corresponding distance-pieces d d d. e e etc. are bolts of
non-magnetic material by which the poles of each magnet are firmly held together
and in position upon the bed H H. The outer or neutral part of each magnet is
supported upon a ledge C projecting from one of a pair of frames carried across
and fixed upon the bed of the machine, and is held firmly to the vertical part H¹
of such framing by set-pins ff etc. E E etc. are non-magnetic straps or distance-
pieces by which the (North) pole A is distanced from the (South) pole B¹, so as to
rigidly maintain these poles in their proper position in relation to one another and
to the armature F. The armature is omitted in figure 1 for convenience of
illustration, but the shaft G upon which it is fixed is shewn passing between the
magnets.
The drawing on sheet 2 herewith illustrates a dynamo-electric machine, con-
structed according to this invention, with two magnets having their common axis
vertical. Figure 3 is a vertical longitudinal section of the machine, but with the
armature and driving pulley shewn in elevation, and figure 4 is a transverse
vertical section on line y y of figure 3. In these views the parts corresponding to
those shewn in figures 1 and 2 are similarly lettered. J J are standards carried
upon a bed H H, and supporting a plate K from which the upper magnet A A¹ is
carried by set-pins f1f1 etc. The bearings for the armature spindle G are formed
or carried in these standards, as shewn. In lieu of the distance-pieces lettered c
and d and straps lettered E (figures 1 and 2) non-magnetic rings L L are fixed,
one at each side, to the ends of all the magnet poles by means of set-pins j j etc.
These rings serve not only to properly and rigidly distance apart the two poles of
a magnet, but serve also to rigidly maintain each pair of poles in proper position in
relation to the other pair and to the armature. The outer or neutral part of the
lower magnet is supported direct upon the bed, as shewn, and held firmly thereto
by means of set-pins ƒ ƒ* etc.
I will now describe my improvements in winding the armature of a dynamo-
electric machine, and that the description may be clearly understood I will refer at
once to figure on sheet 3 of the drawings herewith, which illustrates a drum
armature wound according to my present invention. Sixteen coils, by way of
example, are shewn to be laid upon the armature. The first coil is figured 1
and 1, the first division of the coil being figured 1 and the second division 1*, and
all the coils are figured in two divisions in an analogous manner. In winding the
first division a commencement is made at the point a from front to back, and the
wire passes thence across the back of the armature to b, from thence across the face
to the right of a, thence backwards and down behind the armature to imme-
diately below b and so on until, in the case illustrated, four wires (but of course
any number that may be required) are laid on, the winding being completed at the
front at c.
The two divisions of the coil are laid on so that the surface of
the armature between them, that is between their nearest points, is a quarter of a
circle. The coil 2, 2*, is next laid on in exactly the same manner as the first coil,
the division 2 of the coil being laid on immediately inside the division 1* of the
first coil. The coil 3, 3*, is then laid on precisely as the coil 2, 2º, as is also the

page_text: coil 4, 4, the division 4* coming immediately to the right of the division 1 of
.the first coil. Four coils have now been laid on around the armature, with a clear
quarter of a circle between the nearest points of the divisions of each coil, and
each coil is thus far disconnected from any other coil. I now commence to lay on
four more coils beginning with coil 5, 5, the division 5 of which is laid on
immediately to the right of the division 4*. This coil 5, 5, is laid on precisely as
the other coils described, and then coil 6, 62, is laid on, the division 6 being just
within the division 5* just as the division 2 was laid on within the division 1°.
Coils 7, 7, and 8, 8, complete a second set of four coils, and then comes coil
9, 9, etc. exactly as before until the whole surface of the armature is wound. The
end of each coil is then connected up to the commencement of the next coil
adjacent thereto, thus:-The end of coil 1, 1, that is the end of the division 1°
is connected up to the commencement of the coil 5, 5*, that is to the commence-
ment of the division 5, and similarly the end of the division 5* is connected to the
commencement of the division 9, and so on throughout the coils. Each connection
between two coils is brought down to a commutator strip, as shewn.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
:-
T
1. The combination constituting the general arrangement and means of fixture
of magnets for a four-pole dynamo-electric machine, substantially as herein
described and shewn, according to two modifications, by figures 1 to 4 of the
drawings herewith.
2. An armature of a dynamo-electric machine wound substantially in the manner
herein described and shewn by figure 5 of the drawings herewith.
Dated this twentieth day of February 1886.
STEPHEN WATKINS,
Agent for the Applicant.