Note: Descriptions are shown in the official language in which they were submitted.
3~)~
The pres~nt ~lic~ti~n is a d3yisional o~ appli~ation
~e~ial No. Z88,~12 f~led Octobe~ 13, ~77O
The p~esent ~nVention xelates to dynamoelectric field
mem~erS such as ma~ be produced by windinyr to a field winding
~nd to m~th~ds and apparatus for producing field windings and
field assel~lies.
2. Prior ~rt
It is ~nown in the prior art to wind portions such as
individual coils of a field member by the edge winding of
strapping ~hile such edge wo~md coils have been suggested for
use in numerous applications, it has not heretofore been the
practice to produce complete field members having plural coils
by a continuous winding produced from an uninterruptedly contin-
uous length of conductive strapping, portions of which may be
edge wound.
Summary of *he Invention
In the present invention, field members of the type used,
for example, in the production of automobile starter motors, are
wound from start to finish with an uninterruptedly continuous
length of conductive wire or strapping which preferably has an
insulating coating. In one embodiment disclosed, the winding
comprises interconnected coils, and the apparatus for accom-
plishing the winding includes a mandrel having core pieces, on
for each coil, the strapping being edge wound successively about
each of the core pieces. The portions of the strapping con-
necting between adjacent coils are edge bent and each extends
from the radially outermost convolution of one coil to the
radially innermost convolution of the next adjacent coil. In
a modification, the cores upon which the strapping is wound are
detachable from the mandrel and transferable with the strapping
to provide pole pieces for a dynamoelectric field member. In
both embodiments, the mandrel is constructed so that the strap-
ping may be supported in position to be guided upon the core
-- 1 -- .
.
~5236~C~
pieces and the man~rel moved rotationally abollt an axis perpen-
~ dicular to its major axis for ca-lsing coils to be formed thereon
and rotationally about its major axis for forming co~necting
portions between coil5.
When using a n~andrel having detachable core pieces,
removable supports are provided for temporarily holding the core
pieces ~hile the winding is being made. After the winding is
completed, the supports are removed, the coil shapes are formed
as desired, and the mandrel with the removable core pieces is
inserted into a stator housing or ring, The core pieces are then
connected to the ring by threaded bolts or the li]ce and the man-
drel removed from the ring and the winding and pole pieces are
thereby assembled to the ring.
Brief Doscri~tion of the Drawings
Figure l is a perspective view illustrating a starter motor
field winding known in the prior art.
Figure 2 is a perspective view illustrating a starter motor
field winding accomplished in accordance with the present in-
vention and having electrical characteristics comparable to th0
winding of Figure lo
Figure 3 is a perspective view illustrating a mandrel upon
which the winding of ~igure Z has been ~ormed by edge l~inding.
~ igure 4 is a section view taken diametrically across the
stator for an automotive starter motor utili~ing the field member
illustrated in Figure ~
Figure 5 is an exploded perspective view illustrating a
mandrel with detachable core pieces and apparatus used during
the winding of a field winding on the detachable core pieces.
Figure 6 is a section view taken diametrically across the
mandrel and associated parts of Figure 5 after the field winding
has been wound.
Figure 7 is a section view taken diametrically across a
stator for an automotive starter motor and a mandrel of the
0
t~-pe shown in ~igures 5 and 6 and lllustrates one step in the
ass~mbly of the field winding wherein the core piece~ are used
as the field pole pieces. ~ ~
Figure 8 is a perspective view illustrating in simplified
form apparatus for use with a mandrel for windi~g the field
winding of this invention. In Figure 8 the maIldrel illustrated
is the mandrel sho~7n in ~i~lres 5 and 6.
Figure 9 is an illustration of a forming step subsequent
to the winding of the coils.
LO Fi~lre 10 is a perspective ~ie~ illustrating steps in
the assembly of the coils to the stator housing or ring.
Figure 11 is a perspective view similar to ~igure 10 and
illustrating a further step.
Detailed Description of the Preferred Embodiments
Referring to the drawings~ reference numeral 10 in Figure 1
designates a stato~ winding of the type commonly used in starter
motors for automobiles. The conductive wire 11 used to fabri-
cate the ~inding is commonly referred to as strapping. To
simplify this prior art illustration, insulation interleaved
~0 with the strapping has been omitted. Such strapping comprises
a thin~ generally continuous wire strap having a thickness
substantially less than the width of its major sides. When such
strapping is wound by bending the strapping about an axis
parallel to the major sides thereof 9 the resultant bend or
winding is described as flat bent or flat wound. When the strap-
ping is wound by bending about an axis perpendicular to the major
sides of the strapping, the resultant winding is referred to as
edge bent or edge wound~ The winding of Figure 1~ having been
accomplished generaLly by bending the strapping about axes
~0 parallel to the major sides of the strappingt is therefore in
the nature of a flat wound winding.
The winding 10 has 2 first terminal 12 and a second
terminal 14 which are adapted for connection to a battery or
3~0
other source (not shown) ~hen mounted into the housing or yolce
of an electric motor. The first terminal 12 is at the end of
a start end or leg 16 of a first coil 18. Coil lg is flat wound
and convoluted out~ardly from the innermost convolution thereof
to the outermost convolution thereof, At the comme~cement of
the ~inding of the coil 18, its start end 16 is first flat bent
and then edge bent. At the end of the ~inding the finish end or
leg is rotated or twisted approximately 90 about its central
a.~is to form an up~ardly extending twisted termination 20 to
which is soldered a start end or leg 22 of a second coil 24.
The leg 22 is edge bent downwardly and by combined edge and flat
bends rotated approximately 90 about its own axis to commence
the second coil 24, which is flat wou~d outwardly from the inner-
most to the outermost convolution. Its outermost convolution is
twisted to form a termination 26 that is brazed or soldered at
28 to a termination 30 of a third coil 32. Commencing with a
start end or leg 34 which is bent downwardly and then both edge
and flat bent to accomplish a 90 rotation about its own axis,
the third coil 32 is flat wound outwardly from the innermost to
the outermost convolution. The outermost convolution is both
bent and twisted to form the termination 30~ The start leg of
the third coil 32 is soldered or brazed to the start end or leg
36 of a fourth coil 38. The coil 38 is also flat wound and con-
voluted outwardly from the innermost convolution thereof to the
outerlnost convolution thereof. At the commencement of the wind-
ing of the fourth coil 38, its start end 36 is first flat bent
and then edge bent and at the end of the winding the final con
volution includes an upwardly extending leg 40 which is twisted
approximately 90 about it~ center axis to form the termination
14.
As previously indicated~ the winding 10 i5 representative
of prior art. The winding is accomplished by individually
winding the coils 18, 24, 32 and 38 Usillg four separ~te ~inding
machines and then soldering or brazing the terminal ends of the
coils in the manner illustr~ted in Figure 1 Col;sidering
current flow throu~h the coils and assuming a positi~e potential
applied to the first terminal 12 and ground applied to the second
terrninal 14, a positive current will flow counterclockwise about
the first coil 18, clockwise about the second coil 24, counter-
clockwise about the third coil 32, and clocl~ise about the four~h !.
coil 38 if the observer is located outside the periphery of the
winding. It is noteworthy that the sections of strapping which
are used for the winding form four separate coils wherein each
coil required at least one and sollletimes two 90 twists of the
strapping about its own axis for completion of the coil, edge
bending as well as flat bending of the strapping, and brazed or
soldered connections were required to interconnect the coils. ~ ;
Figure 2 illustrates a winding 48 rhich is co~lparable in
terms of electrical characteristics to the prior winding of
Figure 1 but which~ in accordance ~ith the present invention~
has been accomplished with an uninterruptedly continuous length
of insulated strapping 11. The winding is accomplished without
soldering or brazing and t~Yisting or rotation of the strapping
about its own axis as is required on numerous occasions to
accomplish the prior art winding~ A particularly notable feature
is that the winding of Figure 2 is an edge wound winding as
opposed to the flat wound winding of Figure 1.
Progressing through the generally circular winding of
Figure 2~ the winding commences with a start end or terminal 50
; From the terminal 50 the strapping proceeds horizontally to a
flat bend~ from which the strapping proceeds downwardly along a
straight section of a convolution 52~ ~hich is edge wound to form
a coil 54. It can be noted that the successive convolutions of
the coil 54 proceed axially outwardly as they are wound one
adjacent the other. Thus the coi7 54 increases in axial
~23~
thickness as successive convolutions are added to the coil.
Comparing this feature to the flat wound coils of~Figure 1~ it
should be noted that the coils of ~igure 1 each have a sub-
stantially constant axial thickness with respect to an axis
surrounded by the coil~ but each of the coils of the winding 10
has an increasing radial thickness as the number of convolutions
in each such coil increases.
After winding ~f the coil 54~ the finishing portion of the
wire is edge turned to form a starting portion or leg 56 which
continues uninterruptedly into the first con~olution 58 of an
edge wound coil 60 which is ~ound axially outwardly by edge wind-
ing until a final convolution or finishing portion 62 i5 wound.
After completion of the convolution 62, the strapping i9
continued without interruption along a starting portion by a leg
64 which continues without interruption to the commencement of
the first convolut'ion 66 of an edge wound coil 68. It will be
noted that the leg 64 i5 bent do~nwardly so that it does not
span over the third coil 68,- whereas the afore~entioned leg 56
spans from the first coil 54 over the second coil 60. The coil
68 again increases outwardly in axial thic~ness as successive
convolutions thereof are wound.
After winding of the coil 68, its finishing portion
continueC ~ithout interruption along an arm 70 and without
interruption to form the radially innermost starting portion
or con~olution 72 of an edge ~ound coil 74 where~ again~ the
coil progresses axially outwardly in thickness to the final con-
volutlon thereof rhich is edge turned to form a finish portion
or terminal 76. The resultant winding 48 is characterized by
a generally cylindrical shape in which the coils 54~ 60~ 68 and
74 are laterally spaced apart and the ~tart and finish portions
which interconnect the coils are disposed at the upper axial
extreme of the winding as appears in Figure 2.
In ~ddition to the use of edge ~iinding as opposed to the
~Z3~V
flat winding in Fi~lre l and the use of a continuous strapping
in the winding of Fi~lre 2, another notable feature of the
windin~ of Figure 2 is that all coils are wound outwardly from
an axially innermost convolution to an axially outermost convo-
lution. Further~ the winding of Figure 2 is gener~lly circular
whcn viewed fron1 either end thereof and the major surfaces of
the strapping are parallel to the longitudinal axis of the wind-
ing throughout all of the coils and the col~ection~ therebet~.een.
Accordingly~ the entire length of strapping used to form the
winding 48 has its ~ajor surfaces lying essentially along the
periphery of the imaginary cylinder which the coils form. After
completion of the winding 48~ the flat bent part of the start
portion or terminal 50 could be either straightened or cut off.
As an alternative, the winding may be accomplished ~Yithout the
flat bend in the start portion 50. In either event, the winding
48 can be inserted directly into a stator housing or ring and
suitable terminal connections made for electrical connection to
the terminals 50 and 76. No solder or brazed connections are
required in the winding 48, and all connected coils are inter-
connected by edge bent strapping portions having major faceslying substantiall~ in the same imaginary cylinder as the major
faces of the coils.
Considering the electrical characteristics of the winding
48, one can consider that the starting terminal 50 is connected
to a source of positive ~oltage~ and that the finishing ter~inal
76 is connected to ground. ~ith such connections~ a positive
current as ~seen" by an observsr outside the winding will flow
counterclockwise in the coil 54, clockwise in the coil 60,
count~rclockwise in the coil 68 and clockwise in the coil 74
to ground at the terminal 76. The electrical result will be
basically the sam~ as for the prior art coil illustrated in
Figure l.
Figure 3 illustrates the general manner in which a winding
o
such as dcscribed in reference to Fi.gure 2 can be accomplished
on a malldrel~ generally designated 80. The mandrel 80 com-
prises a generally cylindrical body or arbor having four ou-t-
.ardly projecting and generally rectang~llar cores 82~ 84~ 86
and 88 bounded by respective side walls or shoulders 82a, 84a,
86a and 88a. Only the cores 82 and 88 and their side ~alls 82a
and 88a appear in the drawings~
A piece of strapping 11 is secured at one end thereof~
forming the start end 50 of the winding 48, to one end of the
~andrel 80 by means of a clamp 90 secured by a fastener 92
The strapping is so secured to the mandrel 80 that, ~ith a
single 90 degree bend~ the strapping can be flat bent to
commence the innermost convolution 52 of the coil 54 which
is ~ound edgewise about the shoulder 82a to produce cou~ter-
clockwise wollnd coil 54. It may be noted that other means~
not shown~ could ~e pro~ided to grip the start end S such that
the flat bend would be unnecessaryO
The strapping which forms the outermost convolution of the
coil 54 is then turned edgewise, extended circumferentially
adjacent the upper shoulder, not appearing in Figure 3, of the
mandrel core 84, a-lso not appearing in Figure 3, edge bent
do~nwardly and then wound edgewise in the clockwise direction
about shoulder 84a to produce the coil 60 appearing in Figure 2.
Because of the edgewise turning of the strapping after the
winding of the coil 54, it will be noted that the edge of the
strapping engaging the shoulder 82a is the opposite edge of the
strapping which engages the shoulder of the core piece 84. A
study Df Figures 2 and 3 will reveal that the coils wound in a
clockwise direction have the same strapping edges confronting
and engaging the core pieces and those wound in a counter-
clockwise direction have opposite edges confronting and
engaging the core pieces.
The strapping is then continued from the coil 60 peripher-
_ g~
ally about the mandrel 80, cdge bent do~mwardly adjacent theleft hand side of the core 86, not appearing in ~figure 3~ and
then edge wound about such core to accomplish the counter-
clock~ise ~inding of the coil 68 which appears in Figure 2.
The strapping is then continued from the coil 68 and along
the upper shoulder 88a, as appears in Figure 3, and edge wound
clockwise about the core 88 to accomplish the coil 74. The
last convolution of the coil 74 is permitted to extend vertically
up~ardly as appears in ~igure 3 to form the terminal 76 ~hich
also appears in Figure 2.
Figure 4 schematically illustrates a starter motor field
assembly using the winding of ~igure 3. After release of the
cl~mp 90 illustrated in Figure 3, the ~inding is pulled outwardly
and away from the mandrel 80~ returned and formed as needed to
a generally circular shape~ and inserted into a hollow~ cylin-
drical stator housing or ring 94. Four indiYidual pole pieces
identified by the reference numeral 96, and each preferably
surrsunded by insulating sleeves 97~ are then fastened in a
circular array to the stator ring at 90 degree circumferential
angles by means of suitable fasteners 98 threaded into the pole
pieces 96 so that the pole pieces 96 project inwardly of the
ring 94. In such assembly, both the axially and circumferentially
extending side walls of the pole pieces 96 are confronted by
the radially irlnermost edge surfaces of the strapping but
insulated from the strapping by the sleeves 97. Only the axially
extending side walls~ designated 99~ are illustrated in the
section of ~igure 4 As is conventional, these are out~Tardly
flanged or flared to retain the coils thereon. In the illustra-
tion of Figure 4~ there is a substantial spacing between the
curved inside surface of the ring 94 and the radially outermost
surfaces of the coils 549 60, 68 and 74. In practice~ the
radial dimensions of the coils 54, 60~ 68 and 74 relative to
the radial length of the pole pieces 96 is preferably s~ch that
_ g _
3~(~
the flared side walls 99 compress the several coils 549 Go, G8
and 74 ag~inst the incide surface of the stator ri~n~ so that
the coils are snugly retained on the ring. Suitable terminal
connections~ not sho-~ because well ]~lo~ to those skilled in the
art~ are then provided for connection of the start and finish
portions 50 and 76 appearing in Figure 2 to an electrical source.
The field assembly is thus seen to include a one-piece wind-
ing comprising a single lengtll of conductive strapping edge wo~d
into the laterally spaced ~nd connected coils 54, 60, 68 and 74 9
one coil surrounding each of the pole pieces 96. Since the
strapping forming the coils is coated with insulating material~
there is electrically insulating means between adjacent convo-
lutions of each coil. As possible alternati~es, insulation
could be formed between the coil convolutions after the winding
is completed, or insulating strips could be wowld with the
strapping. When assembled in the ring 94, the adjacently
located colls are connected by ed~e bent portions of strapping
integral with the coils and extending from a finishing~
radially outermost portion of one coil to a starting, radially
innermost portion of the adjacently located coil. As is
obvious from an inspection of the drawings~ the ~ajor sides of
the coils ard al~o the connecting strapping portions between
them are substantially concentric with the inside surface of
the ring 94. The same would be true of the connection between
coils 54 and 74 if either one or both of their adjacent termina_
tion legs 50 and 76 are edge bent to produce the connectionO
Figures 5, 6 and 7 illustrate a modification wherein a
- mandrel, generally designated 300) comprises an assembly of
parts including core or pole pieces about which coils are edge
wound. Upon completion of the winding, the core or pole pieces
are separated from the assembly along with the winding for inser- j
tion into a stator yoke wherein the core pieces are fastened to
the stator yoke so as to function as stator pole pieces.
- 1 0
' .
v~
The mandrel 300 can be seen to comprise a generally cylin~
drical body or arbor 301 having radially outwardly e~tending ~e~s
302 along the length thereof. The radially extending surfaces of
the keys 302 are identified by the reference characters 304 and
306~ respectively. The keys 302 are flanked by recessed~ axial-
ly extending, arcuate surfaces 308, there being four such arcuate
surfaces 308, each bounded by a pair of radial surfaces 304 and
306. The keys 302 are designed to slidably receive bet~een them
core pieces 310, there being one core or pole piece 310 for each
arcuate surface 3080 Thus for a .inding having four coils~ there
are four core pieces 310 as illustrated.
Each core or pole piece 310 comprises a generally rectangu-
lar body member 312 having arcuate flanges 314 projecting from
each axially extending side walt and having a convexly curved
outer surface 316 and a concavely curved inner surface 318. The
core pieces 310 are shaped to become the pole pieces for the
field assembly as will be described belo~t and may be shaped
identically to pole pieces presently in use. _
As best sho~.~ in Eigure 6, the keys 302 a~d the arcuate
surfaces 308 are so constructed that the flanged portion of the
core pieces 310 can be slidable in either axial or radial
directions relative to the axis of the arbor 301 to be snugly
received thereby. The core pieces 310 can then be assembled in
abutting relation with the arcuate surfaces 308, whereupon the
core pieces 3I0 provide the same function as the core pieces
82f 84, 86 and 88 illustrated in Fi~lre 3~ Since the pieces 310
will become the pole pieces of the completed field assembly, an
insulating sleeve 320 is placed on each of the pieces 310 prior
to the winding of coils thereon.
The pieces 310 are clamped to the arbor 301 by means of a
pair of sliding clamp members 322 and 324 which may be of
identical construction. Each has an end platc designated 326
apertured at 328 to receive a shaft part 330 or 332 projecting
3~
from the opposite ends of the mandrel 300 and four cl<~nping
fingers 334 projecting from the corners of the en~ plate 326.
The clamp ~nembers 322 and 324 are adapted to be extended over
opposite ends of the arbor 301 with each of the clamp fingers
334 centered over one of the keys 302 and with the a~ially ex-
tending side edges of the clamp fingers 334 overlying the flange
portions 314 of the core pieces 310 and the parts of the insu-
lating slee~e 320 lying against the flanged portions 31~. As
clearly illustrated in Figure 6~ each clamping finger 334 spans
across adjacent flanges 314 of adjacent core pieces 310 when the
parts are assembled. The arbor 301 is substantially the same
length as the pieces 310 and the clamp fingers are sliglltly less
; than one-half said length. Accordingly~ the end plates 326 of
the clamp members 322 and 324, upon assembly of the mandrel 300
centrally locate the pieces 310 on the arbor 301. ~rhen -~
assembled to the arbor 301, the fingers 334 of the clamp member
322 are aligned with and confront the corresponding fingers of
the clamp member 324. This assembly is sho~ in Figure 8. The
inside surfaces of the side edges of the clamp fingers 334 can
engage the core or pole piece flange portions 314 with a suffi-
ciently close friction fit that the assembled mandrel 300 will
remain assembled unless forcibly disassembled. Alternatively~
or in addition, separate means (not shown) could be provided for
holding the clamp members 322 and 324 in assembled relation to
the arbor 301.
The assembled mandrel comprising the arbor 301 t the core
pieces 310, and the clamp member~ 322 and 324 has essentially
the same configuration as the mandrel 80 illustrated in Figure
~herefore, strapping can be edge bent or wound around the
30 side walls or shoulders of the core pieces 310 to form coils and
edge bent to duplicate the connecting portions 56, 64 and 70
shown in Figure 2D Fig~re 6 shows the mandrel 300 with com-
pleted coils designated 336~ 338~ 340 and 342 wound thereon.
-12-
.
o
~ 'ith reference to Figures 6 alid 7, the core or pole pieces
31Q ha~e centrally located threaded apertures 344 extending
therethrough so that they may be used as the pole pieces of a
completed starter motor field assembly 345 sho~ in Figure 7
The field assembly 345 includes a stator housing or ring 346
which has an insulating liner 348 and which also has apertures
for recei~ring scre~s 350 for attachment of the pole pieces thereto,
~ igures 8-10 illustrate in simplified form the steps
followed in the manufacture of the starter motor field assembly
345. The winding of the coils on the mandrel 300 can b0 accom-
plished as illustrated in Figure 8 wherein the shaft parts 330
and 332 of the arbor 301 are Journalled for rotation in opposed
parts of a yoke 352 rotatably driven by a yoke drive assembly 354
about an axis extending centrally through the mandrel 300 per-
pendicular to its longitudinal axis. The mandrel 300 may be
rotated about its longitudinal axis by a rack 356 mounted on the
yoke 352 and ~ri~ren by a dri~e cylinder 35O or the like and which
engages a pinion 360 mounted on the shaft part 332, One end of
the strapping 11 can be clamped to the cla~p member 322 and
guided from a suitable strapping source (not sho~.~) by a strap
guide member 362. As conventional in other winding procedures,
the strapping is placed under tension at its source. Thererore,
the coils may be edge bent or wound about the core piece 310 by
rotation of the yoke 352 and the connecting strapping parts
between coils edge bent by rotation of the mandrel 300 upon
energization of the cylinder 358 whereupon the racX 356 rotat-
ably drives the pinion 360. The yoke 352 is rotated in either
clockwise or counterclockwise directions to cdge wind +he -oi ~ -
in the desired directions about the pieces 310. Suitable tooling
may be pro~ided to assist in edge bending the strapping as
necessary to wind the coils and rorm the connections between coils.
It will be noted in Figure 6 that the coils are edge wound
around the pole pieces with their radially innermost major
3~
surfaces lying flat against and suppcrted by flat surface por-
tions of the clamp fingers 334. Accordingly the l~ajor surface
of each convolution thereof is substantially perpendicular to
radial lines extending centrally through the apertures 344~
After the windin~ of the coils in the m~lner described above in
connection .ith Figure 8 the strapping is se~ered from its
source and the mandrel 300 is remo~Ted from the yoke 352 and the
clamp members 322 and 324 then removed from the arbor 301~ The
strapping 11 forming the winding is typically quite stiff so
that the completed winding itself will retain the core or pole
pieces 310 on the arbor 301. After removal of the clamp members
322 and 324 the arbor 301 carrying the pole pieces 310 with the
winding thereon is moved to a coil forming machine which modifies
the shape of each of the coils so that they have an arcuate outer
periphery concentric with the arbor 301 and are suitably shaped
for insertion into the stator ring 346. Forming machines are
conventional in the industry and may include as shown in Figure
9 one or more forming dies or press members 364. As apparent
from an inspection of Figure 9~ advancement of the member 364
to~Yard the longitudinal axis of the arbor 301 will cause the coil
342 to be bent or formed into a circular arc for insertion into
the stator ring 346. All coils wound on the pieces 310 are
either simultaneously or sequentially formed to the desired a.c.
The arcuate or circular configuration of all of the coils is
clearly shown in Figure 7.
After forming of the coils the insulating liner 348 is
preferably ~rapped around the core or pole pieces 310. As
illustrated in Figure 10 the liner 348 may conveniently comprise
an insulating paper or the like sheet having plural apertures
366 which are provided to permit contact between the core or pole
pieces 310 and the inside surface of the stator ring 346. The
liner 348 is wrapped around the assembled arbor and pole pieces.
After wrapping~ its ends can be connected as by a piece of tape
-14-
3~)
(not sho~n~. This assembly is then inserte~ into the stator ring
346 ~nd the scre~s 350 ~re then inserted through~the apertures
in the stator ring and thre~dedly engaged with the pole pieces ~10
to affix them along with the winding and the insulating liner 348
to the ring 346. At such time the parts have the appearance
illustrated in Figure 7. Thereafter~ the arbor 301 is removed
from the assembled fleld assembly 345 as sho~n in ~igure 11, read~
for reuse in the manufacture of another field assembly. As
believed apparent J the winding and assembly method illustrated in
Figures 8-11 can be accomplished manually with the use of simple
tools~ or the entire assembly process could be carried out by
automatically operating machines with the potential for sub-
stant.ial savings in the cost of Manufacture of the conventional
starter motor field assemblies ~tili~ing the separately wound
coils illustrated in Figure 1.
Referring to ~igures 3 and 8~ the winding apparatus shown
in Figure 8 could be used for the winding of coils on the man~
drel 80 ~.~hich would be used instead of the mandrel 300. In such
event, the coils would be wound and the connections between coils
formed by repeated rotations of the mandrel 80 ab~ut the axis of
rotation of the yoke 352~ i.e., perpendicular to the longitudi-
nal axis of the mandrel 80, and about~ the longitudinal axis of
the mandrel ~0 in the same manner in which the coils are formed
on the mandrel 300. After the coils are wound on the mandrel 80,
the coil terminal portion 50 is released from the clamp 90 ~-here-
upon the winding can be removed by hand. The coils can then be
formed to the desired arcuate configuration and inserted into
the stator ring 94. Prior to such insertion of the coils~ they
would either be wrapped by an insulating sleeve (not shown) ~hich
may be identical to the insulator 348 or such insulating sleeve
may be positioned within the ring ~4L Thereafter the pole pieces
96 with the insulating sleeves 97 thereon would be inserted in-
side the winding located in the ring 94 and mo~ed radially out-
- ~5'~3~
.ardly through the coils and then attached to the stator ring by
the screws or bolts 98 to form the completed fieldtillustrated
in Fi~ure 4.
While the present application describes the m~nner in ~hicl-
a prior art ~inding might be substantially duplicated~ it will
occur to those skilled in the art that numerous variations are
possible.
The particular winding described as illustrative of the
present invention has the first wou3ld and third ~Yo~ld coils wound
counterclockwise~ for example, and the second wound and fourth
~ound coils wound clock~ise. The ~inding techniques described
in the present application~ of course~ include tec}~iques for
shi~ting the direction of wind as from clockwise to counter-
cloc~wise or vice versa, i.e., winding one side of the strapping
against a core when Yinding clockwise and the opposite side of
the strapping against a core when winding counterclockwise; and
the particular sequence of respectively clockwise and counter-
clockwise windings is thus variable to suit the desires of the
customer. Of course, windings having other than four coils
could be made in accordance with the principles of this inven-
tion. Four coils are illustrated since this is the common con-
figuration for auto~7otive starter motor field windings. This
invention is presently believed most suitable for such windings
because of the need for the coils thereo~ to be formed from
strapping.
In addition to a substantial savings in the number Or
operations required to produce a completed field winding~ it is
expected that this invention can be practiced to produce a
savings in the length of strapping used to form a completed
.inding~ Since strapping is normally made from copper which is
relatively expensive~ and since field windings are normally
~ass-produced in very large quantities, a savings of even a
small length of strapping for each ~inding can result in a
-16
;Z3~0
savings of many thousands of dollars a year, It is also con~
templated that new coil confi~urations may be made~possible by
; the practice of this invention and in particular that it may
be possible to obtain field strength characteristics comparable
to the characteristics obtained in the prior art using windings
which occupy a smaller space and, thus~ this invention could
lead to a reduction in the size and weight of automotive starter
motors.
Although the presently preferred embodiments of this
invention have been described, it will be understood that
within the purview of this invention various changes may be
: made within the scope of the appended claims.
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