Improvements in Electric Generators and Motors.
Year: 1899

page_text: Date of Application (in United Kingdom), 22nd July, 1899
Complete Specification Left, 18th Apr., 1900-Accepted, 23rd June, 1900
Improvements in Electric Generators and Motors.
We, BENJAMIN GARVER LAMME, of 230, Stratford Avenue, and JOHN PURINGTON
MALLETT, of 6,728, Simen Avenue, both of Pittsburg, in the County of Allegheny,
and State of Pennsylvania, U.S.A., Electrical Engineers, do hereby declare the
nature of this invention to be as follows:-
Our invention relates to electrical machines, and particularly to the windings
of the armatures or primary members of such machines.
In armatures of electrical machines for use with polyphase currents having
conductors in the form of bars it is customary to employ connectors of one shape
for connecting the ends of the bars forming the primary member or armature
coils of each group and connectors of a different shape for joining the several
groups in series. According to our present invention we make the bar con-
ductors of such dimensions, and join them together in such a manner that all
the connectors are of the same shape and length, and by this means we reduce
the cost of labour and materials, thereby considerably cheapening the con-
struction.
con-
The accompanying drawings shew by way of example machines
structed in accordance with the present invention:
end elevation of a generator having a rotary field-magnet, and a stationary arma-
Figure is an
ture provided with a three-phase six-pole winding. Figure 2 being a diagram
of the winding, the cylindrical core being indicated as developed into a plane.
Figures 3 and 4 are similar views respectively of a three-phase four-pole in-
luction motor, a portion of the end plate being broken away in Figure 3 in
rder to shewn the winding more clearly.
Referring now particularly to Figures 1 and 2, the frame a of the machine
upports a rotary field magnet 6 and is provided with a laminated core c having
lots or grooves for the armature coils, as is usual in machines of this class. In
he machine shewn there are seventy-two of these core slots or grooves, but
bviously the number may be greater or less than that shewn, if desired. These
ots are divided into six groups, this making twelve slots per pole, there being
ur conductors of each phase for each pole.
A .

page_text: As usually constructed, the portions of the armature conductors located in the
slots or grooves of the core are in the form of bars, the ends of these bars being
properly connected outside the core by means of end connectors of suitable form
which are riveted and soldered or bolted, or otherwise fastened to the ends of
the bars so as to make good electrical connection therewith.
In the form of winding shewn in Figures 1 and 2 one of the middle bars of
each group of four bars corresponding to each phase for each pole projects equally
beyond the two ends of the core c. These symmetrically projecting bars are
alternately long and short and are designated respectively as bars d and bars e.
The bars and g at the side of each symmetrically projecting bar, are of inter-
mediate length and project into the plane of the ends of the short bars at one
end of the core and into the plane of the ends of the long bars at the other end,
the long end of the bars f being at the same end of the core at the short ends
of bars g and vice versa. Since there is an even number of bars for each phase
per pole, the groups have alternately two bars f and one bar and one bar f
and two bars g. One end of each of the bars. d is connected by a connector h
to the nearest bar g of the same phase and corresponding to the adjacent pole
at one side. The other end of each of the bars is connected by a connector i
to the nearest bar f of the same phase and corresponding to the adjacent pole
at the other side. The ends of the bars e are connected in the same manner to
the bars f and y except that the connectors extend to different poles in the two
cases.
Except as above indicated, the bars f are joined, by end connectors h and i,
to the bars g of the same phase and corresponding to adjacent poles.
The leads 1-1, 2-2, and 3-3 correspond to the three phases of current and
the ends of the bars to which these are connected are, for obvious reasons, not
joined by connectors h.
.
In Figure 2 we have indicated the core e by broken lines, and the several
poles and the phases of current producing the same by arrow heads, those at the
top corresponding to phase 1, those at the bottom to phase 2, and those in the
middle to phase 3.
This system of arrangement of long, short and intermediate bars and end
connectors is the same throughout the armature, so that as is seen in Figure 2
the end connectors i are symmetrically grouped, there being two end connectors
in each group. At the other end of the core, groups of three alternate with
single end connectors h, thus making an arrangement that is as a whole,
symmetrical, though different from that at the other end of the core.
If the inumber of slots and bars per pole were greater, but an even number,
obviously the grouping would be different from that shewn, but it would still
remain symmetrical and each symmetrically projecting bar would be one of the
two middle bars of a group.
Referring now particularly to Figures 3 and 4, the frame a of the motor is
provided with a laminated core c, the secondary rotating member j being con-
structed with bar conductors and end rings, as is usual in such machines, and
the whole being protected by end plates of suitable construction having open-
ings for ventilation provided with perforated plates or gratings 1.
The core of the primary member in this case is shewn as provided with
sixty slots divided into four groups, this making fifteen slots per pole and five
for each phase per pole, the windings being arranged for three phases of current.
There being an odd number of slots and conducting bars for each group, the
middle bars m and project symmetrically, the former being long and the
latter short, as in the other construction described. In this, as in the other
form also, the respective ends of the middle bars m and n are joined by the con-
nectors o and that project to the right and to the left at the opposite ends of
the corc.
The two bars q for each phase in each group at the left of the middle
bar project equally with the bars m at one end and equally with the bars n at
the other end of the core c. The bars also project unequally to the same

page_text: MOTOTS.
epars q, but their short ends and the long ends of bars q are at the
same end of the core and vice versa.
Each of the middle bars m and is connected at its respective ends to the
nearest bars
5 remaining side bars are connected to the remaining side bars of the same
and of the same phase corresponding to adjacent poles and the
phase corresponding to adjacent poles, as is clearly shewn in Figure 3 of the
drawings.
This arrangement affords a continuous winding that is symmetrical, the con-
nectors at both ends of the core being arranged in groups alternating two and
three per group, except where the leads 1-1 2-2 and 3--3 are brought out
for connection to the external circuit. The three end connectors corresponding
to these leads are, for obvious reasons, omitted.
The outline of the core and the poles and phases of current are indicated in
Figure 4 the same as in Figure 2. In fact, the only difference between these
windings resides in or is due to the difference in the number of slots per pole.
It will be understood that the leads 1-1, 2-2 and 3-3, brought out for con-
nection to the external circuit, may be so connected and combined as to provide
either a star or delta type of winding,
as may be desired.
It will also be understood that this type of winding may be applied to either
the stationary or the rotating member of a machine, irrespective of whether
such machine be a generator or motor, or a combination of the two, and also,
that the number of poles, the number of phases and the number of slots and
conductors per pole may be varied as may be found desirable.
While we have made specific reference to a type of winding in which end
connectors are riveted and soldered or otherwise fastened to the conductors that
re located in the core slots, we do not intend to thereby so limit our invention
s to exclude windings comprising coils the ends of which are integral with
he sides.
Dated the 22nd day of T... tone
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C.,
Patent Agents for the Applicant.
5
ovements in Electric Generators and Motors.
We, BENJAMIN GARVER LAMME, of 230, Stratford Avenue, and JOHN PURINGTON
MALLETT, of 6,728, Simen Avenue, both of Pittsburg, in the County of Allegheny,
and State of Pennsylvania, U.S.A., Electrical Engineers, 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:-
Our invention relates to electrical machines, and particularly to the windings
of the armatures or primary members of such machines.
In armatures of electrical machines for use with polyphase currents having
conductors in the form of bars it is customary to employ connectors of one shape
for connecting the ends of the bars forming the primary member or armature
coils of each group and connectors of a different shape for joining the several
groups in series. According to our present invention we make the bar con-
ductors of such dimensions, and join them together in such a manner that all
the connectors are of the same shape and length, and by this means we reduce

page_text: the cost of labour and materials, thereby considerably cheapening the con-
struction.
The drawings filed with the Provisional Specification shew by way of example
machines constructed in accordance with the present invention. Figure 1 is an
end elevation of a generator having a rotary field-magnet, and a stationary arma-
ture provided with a three-phase six-pole winding. Figure 2 being a diagram
of the winding, the cylindrical core being indicated as developed into a plane.
Figures 3 and 4 are similar views respectively of a three-phase four-pole in-
duction motor, a portion of the end plate being broken away in Figure 3 in
order to shew the winding more clearly.
Referring now particularly to Figures 1 and 2, the frame a of the machine
supports a rotary field-magnet b and is provided with a laminated core c having
slots or grooves for the armature coils, as is usual in machines of this class. In
the machine shewn there are seventy-two of these core slots or grooves, but
obviously the number may be greater or less than that shewn, if desired. These
slots are divided into six groups, this making twelve slots per pole, there being
four conductors of each phase for each pole.
As usually constructed, the portions of the armature conductors located in the
slots or grooves of the core are in the form of bars the ends of these bars being
properly connected outside the core by means of end connectors of suitable form
which are riveted and soldered or bolted, or otherwise fastened to the ends of
the bars so as to make good electrical connection therewith.
In the form of winding shewn in Figures 1 and 2 one of the middle bars of
each group of four bars corresponding to each phase for each pole projects equally
beyond the two ends of the core c. These symmetrically projecting bars are
alternately long and short and are designated respectively as bars d and bars e.
The bars f and g at the side of each symmetrically projecting bar, are of inter-
mediate length and project into the plane of the ends of the short bars at one
end of the core and into the plane of the ends of the long bars at the other end,
the long ends of the bars f being at the same end of the core as the short ends
of bars g and vice versa. Since there is an even number of bars for each phase
per pole, the groups have alternately two bars f and one bar g and one bar f
and two bars g. One end of each of the bars d is connected by a connector h
to the nearest bar g of the same phase and corresponding to the adjacent pole
at one side. The other end of each of the bars is connected by a connector i
to the nearest bar f of the same phase and corresponding to the adjacent pole
at the other side. The ends of the bars are connected in the same manner to
the bars and g except that the connectors extend to different poles in the two
cases.
Except as above indicated, the bars f are joined, by end connectors h and i,
to the bars g of the same phase and corresponding to adjacent poles
The leads 1-1, 2-2, and 3-3 correspond to the three phases of current and
the ends of the bars to which these are connected are, for obvious reasons, not
joined by connectors h.
In Figure 2 we have indicated the core c by broken lines, and the several
poles and the phases of current producing the same by arrow heads, those at the
top corresponding to phase 1, those at the bottom to phase 2, and those in the
middle to phase 3.
This system of arrangement of long, short and intermediate bars and end
connectors is the same throughout the armature, so that as is seen in Figure
the end connectors i are symmetrically grouped, there being two end connectors
in each group.
At the other end of the core, groups of three alternate with
single end connectors h, thus making an arrangement that is as a whole,
symmetrical, though different from that at the other end of the core.
If the number of slots and bars per pole were greater, but an even number,
obviously the grouping would be different from that shewn, but it would still

page_text: inding
3. For an electrical machine a distributed continuous
bars of three different lengths and end connectors all of which are of substan-
tially the same length and form and symmetrically arranged.
4. For electrical machines, armatures or primary members constructed sub-
stantially as described with reference to the accompanying drawings.
1 1000
Ca
W. P. THOMPSON & Co.,
Of London, Liverpool, Manchester and Birmingham.
Dated the 18th day on **p***
W. P. THOMPSON & Co.,
Of London, Liverpool, Manchester and Birmingham.

page_text: remain symmetrical and each symmetrically projecting bar would be one of the
two middle bars of a group.
Referring now particularly to Figures 3 and 4, the frame a of the motor is
provided with a laminated core c, the secondary rotating member being con
structed with bar conductors and end rings, as is usual in such machines, and
the whole being protected by end plates of suitable construction having open
ings for ventilation provided with perforated plates or gratings 7.
th
The core of the primary member in this case is shewn as provided wit
sixty slots divided into four groups, this making fifteen slots per pole and fi
for each phase per pole, the windings being arranged for three phases of curren
There being an odd number of slots and conducting bars for each group,
middle bars m and n project symmetrically, the former being long and t
latter short, as in the other construction described. In this, as in the oth
form also, the respective ends of the middle bars mand n are joined by the co
nectors o and p that project to the right and to the left at. the opposite ends
the core.
The two bars q for each phase in each group at the left of the midd
bar project equally with the bars m at one end and equally with the bars n
the other end of the core c. The bars also project unequally to the sa
degree as the bars q, but their short ends and the long ends of bars
same end of the core and vice versa.
are at
Each of the middle bars m and is connected at its respective ends to
nearest bars and of the same phase corresponding to adjacent poles and
remaining side bars are connected to the remaining side bars of the sa
phase corresponding to adjacent poles, as is clearly shewn in Figure 4 of
drawings.'
This arrangement affords a continuous winding that is symmetrical, the
nectors at both ends of the core being arranged in groups alternating two
three per group, except where the leads 1-1, 2-2 and 3--3 are brought
for connection to the external circuit. The three end connectors correspon
to these leads are, for obvious reasons, omitted.
The outline of the core and the poles and phases of current are indicate]
Figure 4 the same as in Figure 2. In fact, the only difference between
windings resides in or is due to the difference in the number of slots per po
It will be understood that the leads 1-1, 2-2 and 3-3, brought out for
nection to the external circuit, may be so connected and combined as to pro
either a star or delta type of winding, as may be desired.
It will also be understood that this type of winding may be applied to e
the stationary or the rotating member of a machine, irrespective of whe
such machine be a generator or motor, or a combination of the two, and
that the number of poles, the number of phases and the number of slots
conductors per pole may be varied as may be found desirable.
While we have made specific reference to a type of winding in which
connectors are riveted and soldered or otherwise fastened to the conductors
are located in the core slots, we do not intend to thereby so limit our inve
5 as to exclude windings comprising coils the ends of which are integral
the sides.
Ο
Having now particularly described and ascertained the nature of our
invention, and in what manner the same is to be performed, we declare
what we claim is:-
1. For an electrical machine a continuous multipolar winding in whic
or more middle conductors of each phase and pole group are connected
respective ends to the nearest side conductor of the same phase, for the p
specified.
2. For an electrical machine a multipolar polyphase bar winding in
5 the middle or adjacent to the middle bars for the several phases of each
are alternately long and short, the remaining bars being of intermediate l