Improvements in Alternating Current Generators.
Year: 1899

page_text: Improvements in Alternating Current Generators.
I, BENJAMIN GARVER LAMME, of 230, Stratford Avenue, Pittsburg, in the
County of Allegheny and State of Pennsylvania, U.S.A., Electrical Engineer,
do hereby declare the nature of this invention to be as follows:-
My invention relates to single-phase alternating current generators, and has
for its object to improve the construction of the armature so that the coils thereof
can be very easily inserted into their respective slots, without bending or the
exertion of injurious pressure thereon. For this purpose the slots in the arma-
ture core for the reception of the coils are not made radial but the sides thereof
in each group of coils are made parallel to each other so that the distance
between two slots intended to receive a coil is the same at the bottom of the slots
as it is at the top of the slots, that is to say, on the outer periphery of the
armature.
The invention will be understood from the accompanying drawings in-which
Figure 1 is an end elevation of a machine constructed in accordance with my
invention, certain portions being broken away and omitted.
Figure 2 is a development of a portion of the armature core and windings and
Figure 3 is a diagram of a portion of a modified form of armature winding.
The field-magnet of the machine has a frame 1, pole pieces 2, and field-
magnet coils 3 of any suitable construction. The armature core 4 is mounted
upon a spider 5 and is provided with a plurality of groups of parallel slots 6,
one group being provided for each pole. The slots of each group corresponding
to each pole are parallel to each other and to a plane including the armature
axis and the middle point of the segment of the armature surrounded by the
group of coils 7 located in the slots.
In cases where the armature winding is made up of wire wound coils, as in-
dicated in Figures 1 and 2, the coils are separately wound upon suitable moulds
or forms, there being as many sizes of coils as there are pairs of slots in each
group, so that the coils may be readily inserted in the appropriate slots or
channels without bending and substantially without the exertion of pressure
thereon, the terminals of these several coils of each group being subsequently
connected together so that the entire portion of the winding for each pole con-
stitutes in effect a single coil, and the several coils being connected in series
around the armature.

page_text: In cases where a strap winding is employed, each coil for each group corre-
sponding to a pole is bent or coiled into suitable shape for insertion in the slots
and suitably insulated, this form being diagrammatically shewn in Figure 3.
These coils having the several turns of different lengths may then be inserted
in the proper slots or channels and their ends suitably connected to make a
single series winding for the entire armature.
The number of slots or channels per pole may obviously be varied in accordance
with the size and output of the machine and the spaces between the slots or
channels may also be varied from what is shewn. I prefer to have a consider-
able width of core space included within the inner coil or turn of each group
and a comparatively narrow space between the adjacent sides of the outer coils
or turns of adjacent groups in order that all of the conductors at the adjacent
sides of each two adjacent groups of coils may be under each of the field-magnet
poles at the same time, thus insuring more satisfactory results than would other-
wise be attained.
Improvements in Alternating Current Generators.
I, BENJAMIN GARVER LAMME, of 230, Stratford Avenue, Pittsburg, in the
County of Allegheny, State of Pennsylvania, United States of America, 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:-
My invention relates to single-phase alternating. current generators, and has
for its object to improve the construction of the armature so that the coils thereof
can be very easily inserted into their respective slots, without bending or the
exertion of injurious pressure thereon. For this purpose the slots in the arma-
ture core for the reception of the coils are not made radial but the sides thereof
in each group of coils are made parallel to each other so that the distance
between two slots intended to receive a coil is the same at the bottom of the slots
as it is at the top of the slots, that is to say, on the outer periphery of the
armature.
Provisional
Figure 1 is an end elevation of a machine constructed in accordance with my
invention, certain portions being broken away and omitted.
The invention will be understood from the drawings filed with my
Specification in which:-
Figure 2 is a development of a portion of the armature core and windings, and
Figure 3 is a diagram of a portion of a modified form of armature winding.
The field-magnet of the machine has a frame 1, pole pieces 2, and field-
magnet coils 3 of any suitable construction. The armature core 4 is mounted
upon a spider 5 and is provided with a plurality of groups of parallel slots 6,
one group being provided for each pole. The slots of each group corresponding
to each pole are parallel to each other and to a plane including the armature
axis and the middle point of the segment of the armature surrounded by the
group of coils 7 located in the slots.
In cases where the armature winding is made up of wire wound coils, as in-
dicated in Figures 1 and 2, the coils are separately wound upon suitable moulds

page_text: or forms, there being as many sizes of coils as there are pairs of slots in each
group, so that the coils may be readily inserted in the appropriate slots or
channels without bending and substantially without the exertion of pressure
thereon, the terminals of these several cons of each group being subsequently
connected together so that the entire portion of the winding for each pole con-
stitutes in effect a single coil, and the several coils being connected in series
around the armature.
In cases where a strap winding is employed, each coil for each group corre-
sponding to a pole is bent or coiled into suitable shape for insertion in the slots
and suitably insulated, this form being diagrammatically shewn in Figure 3.
These coils having the several turns of different lengths may then be inserted
in the proper slots or channels and their ends suitably connected to make a
single series winding for the entire armature.
The number of slots or channels per pole may obviously be varied in accordance
with the size and output of the machine and the spaces between the slots or
channels may also be varied from what is shewn. I prefer to have a consider-
able width of core space included within the inner coil or turn of each group,
and a comparatively narrow space between the adjacent sides of the outer coils
or turns of adjacent groups in order that all of the conductors at the adjacent
sides of each two adjacent groups of coils may be under each of the field-magnet
poles at the same time, thus insuring more satisfactory results than would other-
wise be attained.
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:-
:
A dynamo electric machine having an armature provided with either a wire
winding or a strap winding and constructed as herein described and shewn in
the drawings.
Dated the 21st day of September 1900.
F. W. LE TALL,
Chartered Patent Agent, The Westinghouse Patent Bureau,
Westinghouse Building, Norfolk Street, Strand, London, W.C.