Method for stator coil lacing

A method and apparatus for lacing stator coil windings and leads is provided. Lacing of the stator coil windings and leads is performed during an automated process which occurs while the stator is situated on a pallet which is moved by a conveyer belt through a manufacturing facility. The pallet includes an inner ring and an outer ring rotatably disposed therein. The inner ring supports the stator and allows the stator to be rotated during lacing. The outer ring is rotated at the same rotational speed and direction as the inner ring and includes a plurality of clips for releasably securing leads of the stator. The pallet further includes a lead lift assembly which is movable in a substantially vertical direction. Upon introduction of the pallet to a lacing station in the manufacturing facility, a vertical positioning device engages the lead lift assembly from beneath the pallet and raises the assembly to a predetermined height. Further, a drive gear engages the outer ring and serves to rotate the outer and inner ring according to a predefined lacing protocol. During lacing, the lead lift assembly positions the leads of the stator such that the leads are laced in a desired manner.

TECHNICAL FIELD 
The present invention relates to a stator coil lacing device for lacing end 
windings and lead cords of an electrodynamic machine. More particularly, 
the present invention relates to a stator coil lacing device having lacing 
capabilities which eliminate the need for an arbor and provide for 
automated lead cord positioning. 
BACKGROUND OF THE INVENTION 
Induction motors typically include a stator and a rotor. The stator 
includes a metallic core with a plurality of coils or windings running 
through the core. An alternating current is passed through these coils to 
generate an alternating magnetic flux field. The rotor includes a 
plurality of coils or windings in which an alternating current is induced 
by the alternating magnetic flux field of the stator. The end coils or end 
turns of the stator are grouped together at axial ends of the stator and 
are laced or stitched together to prevent interference with other 
components of a device. The end turns may be coated with an epoxy or resin 
subsequent to stitching. This coating helps to reduce movement of the 
wires and provides an insulated barrier between the wires and other 
objects. Lacing in this case helps assure that the coils are tightly 
grouped together prior to coating. 
During manufacture, each stator typically is placed on a pallet which is 
moved by a conveyer belt through the manufacturing facility. As part of 
the manufacturing process, each stator is introduced to a station at which 
lacing thereof occurs. Use of a stator coil lacing machine avoids many of 
the manual operations otherwise necessary for lacing or stitching stator 
end coils and thus reduces labor costs and increases productivity and 
quality. At the lacing station, an operator typically lifts the stator and 
places the stator on the lacing machine. The lacing machine generally 
includes a worktable having a cylindrical arbor protruding upward from a 
central portion of the worktable. The arbor serves to ensure proper 
placement of the stator on the lacing machine and aids in rotating the 
stator as lacing takes place. Once lacing is completed, the stator is 
lifted off the arbor and removed from the lacing machine to be placed back 
on the pallet. The larger the longitudinal length of the arbor, the more 
effort is required to place the stator thereon and remove the stator there 
from. Insertion and removal is especially difficult given the oftentimes 
heavy weight of the stator which includes a heavy metallic core. While use 
of a lacing machine provides advantages in lacing the stator coils, the 
need physically to move the stator from the conveyer belt pallet to the 
lacing machine and back again to the pallet is a tedious process which 
impedes the overall manufacturing process. 
One characteristic of some stator coil lacing machines is that the leads of 
the stator coil windings must be manually held and moved during lacing of 
the coils of the stator. Typically, a stator includes several groups of 
leads for supplying power and other signals to the stator. The leads must 
be held and moved in order appropriately to position the leads with 
respect to one or more lacing needles of the stator coil lacing machine. 
Oftentimes the leads are manually moved and positioned such that a portion 
of each lead is stitched to the coil in a desired manner. This allows the 
leads to extend from the stator at a desired location rather than loosely 
falling at random positions. The desired location from which the leads 
extend may be caused to correspond to openings in the stator housing which 
provide the leads with access outside the housing. Thus, one or both of 
the hands of the operator of a stator coil lacing machine is/are often 
preoccupied in positioning the leads during lacing of the coils of the 
stator. This has the disadvantages of preventing the operator from 
performing other tasks during stator coil lacing and thus lowers his or 
her productivity. In addition, an operator needs to be cautious so as to 
not carelessly come in contact with moving components of the stator coil 
lacing machine such as the lacing needles. 
Therefore, there is a need in the art to reduce the amount of manual 
intervention needed during lacing of stator coil windings so as to 
mitigate the aforementioned shortfalls of conventional methods and 
devices. 
SUMMARY OF THE INVENTION 
Briefly, the present invention provides for automatically lacing of stator 
coil windings. Lacing of the stator coil windings and leads is performed 
while the stator is situated on a support such as a pallet which is moved 
through a manufacturing facility, for example, via a conveyer. According 
to an aspect of the invention, lacing of the stator occurs directly on the 
pallet and therefore it is not necessary for an operator to lift the 
stator off the pallet and place the stator over an arbor of a separate 
lacing machine in order to lace the end windings and leads. Furthermore, 
according to an aspect of the invention, the automated lacing process 
provides for automatically lacing the end windings and leads of the stator 
according to a predefined lacing protocol to provide for the leads to 
extend from the end windings at one or more desired locations without the 
need for an operator to manually guide the leads during lacing. Thus, the 
operator is free to perform other functions during the lacing process 
thereby increasing overall efficiency, and manual intervention by the 
operator during the lacing operation is substantially mitigated as 
compared to conventional lacing operations. 
According to an aspect of the invention, in a manufacturing facility, a 
conveyer moves a plurality of stators from one station to the next in 
order to complete a manufacturing cycle. Each stator is placed on a 
respective pallet which moves with the conveyer. Preferably, each pallet 
includes a ring assembly for assisting in the lacing of stator coil 
windings and leads at a lacing station. The ring assembly is rotatably 
disposed in the pallet to rotate the stator during the lacing procedure. A 
slidable gear assembly situated at the lacing station engages with each 
ring assembly disposed in a pallet introduced to the lacing station and 
rotates the ring assembly according to a lacing protocol. 
According to one particular aspect of the present invention a manufacturing 
facility includes a conveyer system and a plurality of supports coupled to 
the conveyer system for movement of the supports to a plurality of 
stations in the manufacturing facility. A stator is positioned on one of 
the plurality of supports at a first station and is moved by way of a 
conveyer system to a second station. At the second station end windings 
and/or leads of the stator are laced while the stator remains on the 
support. 
According to another aspect of the present invention, a method of lacing 
the end windings and/or leads of a stator situated on a pallet which has a 
first ring rotatably disposed within the pallet, includes the steps of 
placing the stator on the first ring of the pallet, rotating the first 
ring according a predetermined lacing protocol, and lacing the end 
windings and/or the leads during at least a portion of the rotation of the 
first ring. 
According to still another aspect of the present invention, a pallet which 
is useful in a manufacturing facility in which a conveyer system moves the 
pallet between a plurality of stations includes a base portion, a rotating 
means disposed in the base portion for rotatably supporting a stator, and 
a lead cord positioning means movably coupled to the base portion, the 
lead cord positioning means movable in a substantially vertical direction. 
According to yet another aspect of the present invention a stator is 
produced by the process of positioning the stator on a pallet at a first 
station in a manufacturing facility, moving the pallet to a second station 
in the manufacturing facility by way of a conveyer system, and lacing end 
windings and/or leads of the stator positioned on the pallet at the second 
station. 
According to yet still another aspect of the present invention, a system 
for lacing at least one of end windings and leads of a stator includes a 
pallet for supporting the stator. The pallet includes a means for lifting 
the leads, and a means for rotating the stator. The system further include 
a means for lacing the at least one of end windings and leads of the 
stator. 
According to still another aspect of the present invention a system for 
lacing at least one of end windings and leads of a stator includes a 
pallet for supporting the stator, the pallet includes a base portion, a 
first and second ring rotatably disposed in the base portion, a means for 
rotating the first and second rings at substantially the same rotational 
rate, and a means for lifting the leads, the means for lifting movably 
supported by the base potion between the first and second rings. The 
system further includes a conveyer system for supporting the pallet and 
moving the pallet between a plurality of stations, and a means for lacing 
the at least one of end windings and leads of the stator disposed at one 
of the plurality of stations. 
According to still another aspect of the present invention, a device for 
lacing at least one of end windings and leads of a stator includes a 
bobbin, a lacing needle, means for supporting the bobbin and the lacing 
needle with respect to one another for lacing the at least one of the end 
windings and leads, and means for vertically positioning the bobbin into 
and out of a cavity defined by the end windings. 
To the accomplishment of the foregoing and related ends, the invention 
then, comprises the features hereinafter fully described and particularly 
pointed out in the claims. The following description and the annexed 
drawings set forth in detail certain illustrative embodiments of the 
invention. These embodiments are indicative, however, of but a few of the 
various ways in which the principles of the invention may be employed and 
the present invention is intended to include all such embodiments and 
their equivalents. Other objects, advantages and novel features of the 
invention will become apparent from the following detailed description of 
the invention when considered in conjunction with the drawings.

DETAILED DESCRIPTION OF THE INVENTION 
The present invention will now be described with reference to the drawings 
in which like reference numerals are used to refer to like elements 
throughout. 
Turning now to FIGS. 1a, 1b and 2, a stator coil lacing station 20 in 
accordance with the present invention is depicted. The stator coil lacing 
station 20 includes a lacing machine, apparatus or system 21 which may be 
separate or may be a portion of a stator manufacturing facility used to 
manufacture stators 20. As is illustrated in FIGS. 1a, 1b and 2, the 
stator 25 is situated on a pallet 28 of a conveyer system 30 and is 
introduced to the stator coil lacing station 20 as part of a stator 
manufacturing process as described in more detail below. The stator 25 
includes a metal core 33, for example, formed from stacked laminations and 
includes conducting wires oriented axially through the metal core 33. The 
conducting wires are grouped together into end coils or end windings 35 
which converge into a generally toroidal shape configuration at upper and 
lower ends 38a, 38b, respectively, of the metal core 33 and define a 
respective cavity 36 at each end 38a, 38b. Leads 50 extend from the end 
windings 35 situated on the upper end 38a of the metal core 33 and are 
used to provide the stator 25 with electrical control and power signals as 
is known in the art. For example, the leads 50 may provide the stator 25 
with three phase power, thermal relay signals, etc. While the present 
embodiment depicts only two sets of leads 50 extending from the end 
windings 35, it will be appreciated that the stator 25 may include any 
number of sets of leads 50 depending on the operational requirements of 
the stator 25. As will be described in more detail below, a portion of the 
leads 50 are stitched to end windings 35 at the lacing station 20 such 
that each set of leads 50 extends from the end windings at one or more 
desired locations. 
As best seen in FIG. 1a, the lacing station 20 includes the lacing machine 
21 for lacing the end windings 35 and leads 50 of the stator 25. The 
lacing machine 21 includes an upper lacing section 22 and a lower lacing 
section 22'. Both the upper lacing section 22 and the lower lacing section 
22' include corresponding components for lacing of the upper portion 38a, 
and lower portion 38b of the end windings 35, respectively. Thus, 
components of the lower lacing section 22' which correspond to components 
of the upper lacing section 22 are identified with the same reference 
numeral but with a prime "'". For sake of brevity, the following 
description will discuss only the components of the upper lacing section 
22, however, it will be appreciated that the components of the lower 
lacing section 22' are similarly connected and configured as shown in FIG. 
1a. 
The upper lacing section 22 is mounted to a frame 68 which is secured to a 
lacing table 70 using mounting bolts 71 or other conventional securing 
techniques such as screws, adhesives, etc. The lacing machine 21 includes 
a positionable lacing needle 69 for lacing of the end windings 35 on the 
upper end 38a of the metal core 33. The lacing needle 69 is secured to 
vertical movement platform 73 of the frame structure 68 via needle housing 
75. The platform 73 is coupled to vertical movement motor 78 via support 
rod 80. The vertical movement motor 78 serves to raise and to lower the 
platform 73 thereby allowing for vertical positioning of the lacing needle 
69. Rotational positioning of the lacing needle 69 is accomplished by 
rotation rod 85 and rotation motor 90. More particularly, rotation rod 85 
connects at one end to rotation motor 90 via gear assembly 93 and at the 
other end to lacing needle 69. Thus, upon operation of the rotation motor 
90, the rotation rod 85 causes the lacing needle 69 to rotate about an 
axis 94 to a desired position for lacing of the end windings 35. The 
lacing needle 69 is also coupled to threading motor 95 via threading rod 
99. The threading motor 95 and threading rod 99 provide the lacing needle 
69 with in/out movement in a direction substantially parallel to axis 94 
of the lacing needle 69. 
The lacing machine 21 further includes a bobbin 103 for providing and 
directing a lacing cord 105 to an appropriate position with respect to the 
coil windings 35 to allow lacing to take place. A rotational direction of 
the bobbin 103 is controlled by bobbin motor 105 via bobbin control rod 
109. The bobbin control rod 109 couples to the bobbin motor 105 via gear 
assembly 111 which rotates the bobbin control rod 109 in response to 
operation of the bobbin motor 105. Similar to the lacing needle 69, 
vertical positioning of the bobbin 103 is achieved by way of the vertical 
movement motor 78 appropriately positioning the platform 73 to which the 
bobbin 103 is secured. More particularly, as shown in phantom in FIG. 1a, 
the vertical movement motor 78 allows both the bobbin 103 and lacing 
needle 69 to be positioned above or below the upper end 38a of the stator 
coil end windings 35 during lacing as indicated by arrows 107. Thus, for 
example, the bobbin 103 may be positioned inside or outside a cavity 
defined by the end winding 35. It will be appreciated that while the 
present embodiment shows the vertical positioning of the bobbin 103 and 
lacing needle 69 to be controlled by the same motor 78, a separate stepper 
motor or other device could additionally or alternatively be coupled to 
each to allow for individual vertical positioning of the bobbin 103 and 
lacing needle 69. 
Also secured to the frame 68 is threading assembly 115. The threading 
assembly 115 is secured to the platform 73 and moves in conjunction with 
the vertical positioning of the platform 73 as controlled by vertical 
movement motor 78. The threading assembly 115 includes a clamp (not shown) 
for securing the lacing cord 105 during certain portions of the lacing 
cycle and includes a shear (not shown) for cutting the lacing cord 105 as 
needed during the lacing cycle. Interaction between the bobbin 103, lacing 
needle 69, and threading assembly 115 is generally known in the art and is 
therefore not discussed in greater detail for sake of brevity. 
Referring now also to FIG. 2, the lacing station 20 includes a slidable 
gear assembly 130 which is coupled to lacing table 70 via track 133. The 
slidable gear assembly 130 includes a bidirectional motor 135 coupled to 
drive gear 140 and is capable of rotating the drive gear 140 in both a 
clockwise and counter clockwise direction. A traction plate 145 is rigidly 
attached to the top of the bidirectional motor 135 and interfaces with the 
track 133 to allow the slidable gear assembly 130 to move horizontally in 
a direction depicted by arrows 136. A pair of traction wheels 134 secured 
to the traction plate 145 provide for movement of the slidable gear 
assembly 130 within track 133. The track 133 includes first and second 
track members 147a and 147b each mounted to the lacing table 70 using 
conventional mounting means and each defining a respective groove 149a and 
149b, for receiving the traction plate 145 and traction wheels 134 of the 
slidable gear assembly 130. A motor 146 (FIG. 1a), attached to a side of 
the lacing table 70, provides motive force to the traction wheels 134 of 
the slidable gear assembly 130 for movement along the track 133. 
Also included at the lacing station 20 is a vertical positioning device 165 
(FIG. 2). The vertical positioning device 165 is used to aid in placement 
of the leads 50 during lacing as discussed in more detail below. The 
vertical positioning device 165 includes a stepper motor 170 having a lift 
member 172 extending therefrom and a lead lift plate 175. The lead lift 
plate 175 is rigidly secured to a top of the lift member 172 and includes 
a pie shaped groove 173 for providing room for the bobbin 103' and lacing 
needle 69' to interface with the end windings 35 on the lower end 35b of 
the stator 25 during lacing. The stepper motor 170 provides for movement 
of the lead lift plate 175 in substantially a vertical direction as 
depicted by arrows 183. The stepper motor 170 is situated on platform 185 
(FIG. 1a) which is secured to the lacing table 70 using conventional 
techniques. 
Turning now to FIGS. 2-4, the pallet 28 is described in more detail. The 
pallet 28 includes the base portion 29 which is generally rectangular in 
shape and includes a pair of flanges 200 suitable for situating the pallet 
28 on the conveyer system 30 (FIG. 1b) for movement through the 
manufacturing facility. To provide for automatic lacing of the stator coil 
end windings 35 and leads 50 at the lacing station 20, the pallet 28 
further includes a ring assembly 210 disposed therein. More particularly, 
the ring assembly 210 includes an outer ring 215 and an inner ring 220. 
As best seen in FIG. 3, the outer ring 210 includes inner and outer gear 
teeth 225, 230, respectively. The outer gear teeth 230 have a pitch angle 
and spacing which is suitable to engage with drive gear 140 (FIG. 2). The 
inner gear teeth 225 have a pitch angle and spacing which is suitable for 
engaging with gear assembly 250. The outer ring further includes lead 
clips 255 connected thereto. As will be discussed in more detail below, 
the lead clips 255 aid in positioning leads 50 during lacing at the lacing 
station 20. 
The lead clips 255, which are best seen in FIG. 5, include a base portion 
257 and a cord securing member 259. The base portion 257 is secured to a 
top surface of the outer ring 215 using flat head screws 258 or the like. 
The securing member 259 is folded across a top surface 260 of the base 
portion 257 and provides a downward force against the top surface 260 for 
releasably securing items therebetween. It will be appreciated that while 
the present embodiment describes clips 255 attached to the outer ring 215 
for securing the leads 50, other fasteners or securing devices may 
alternatively be used. 
Returning again to FIG. 3, the inner ring 220 includes outer gear teeth 275 
disposed about a periphery of the inner ring 220. The outer gear teeth 275 
have a pitch angle and spacing configured to interface with gear assembly 
250. The inner ring 220 includes a recessed step 279 which is a size to 
receive the metal core 33 of the stator 25. The recessed step 279 provides 
for mitigating wobbling and/or falling of the stator 25 situated therein 
during manufacture. Furthermore, an opening 283 in a central portion of 
the inner ring 220 provides space for the end windings 35 on the lower end 
38b (FIG. 2a) of the stator core 33 to extend to an underside of the 
pallet 28 so that the end windings 35 are accessible for lacing or other 
manufacturing steps. 
Both outer ring 215 and inner ring 220 are rotatably disposed in the pallet 
28 to aid in lacing of the stator end windings 35 and leads 50. More 
particularly, the outer ring 215 is disposed in an outer ring receiving 
channel 290 in the pallet 28. A bottom surface 294 of the outer ring 
receiving channel 290 includes a brass bushing (not shown) to facilitate 
rotation of the outer ring 215 within channel 290. The inner ring 220 is 
situated within an inner receiving groove 291which includes inner ring 
receiving ledge 297. 
Similar to the outer ring receiving channel 290, the inner ring receiving 
ledge 297 includes a brass bushing to facilitate rotation of the inner 
ring 220 during operation. It will be appreciated that ball bearings 
and/or other devices may be used in place of the brass bushings to aid in 
rotation of the inner ring 220 and outer ring 215. 
The outer receiving channel 290 and inner receiving groove 291 define a 
stationary middle ring 300. The gear assembly 250 allows for synchronized 
movement of the outer ring 215 and inner ring 220, and is connected to an 
underside of middle ring 300. 
As best seen in FIG. 6, the gear assembly 250 includes three gears. A first 
gear 310 is coupled to the underside of the middle ring 300 via gear axle 
315 and interfaces with the inner gear teeth 225 of the outer ring 215. 
Second and third gears 320 and 325, respectively, are rigidly attached to 
one another and are coupled to the underside of the middle ring 300 via 
gear axle 329. The pitch angle and spacing of the second gear is 
configured to interface with the gear teeth of the first gear 310. The 
pitch angle and spacing of the third gear 325 is configured to interface 
with the outer gear teeth 275 of inner ring 220. The third gear 325 also 
is configured to provide for both the outer ring 215 and inner ring 220 to 
move at the same angular rotation about central axis "A" of the pallet 28 
during lacing. 
In the present exemplary embodiment the outer ring 215 has ten times the 
number of gear teeth 230 as the drive gear 140. Thus, for example, if the 
drive gear 140 were to rotate at a speed of ten revolutions per minute, 
the outer ring 215 would rotate at a speed of one revolution per minute. 
As the outer ring 215 is rotated, the first gear 310 of the gear assembly 
250 is correspondingly rotated via the inner gear teeth 225 of the outer 
ring 215. The first gear 310, in turn, engages rotation of both the second 
gear 320 and third gear 325. Finally, the third gear 325 engages rotation 
of the inner ring 220 via outer gear teeth 275. In order to ensure that 
the inner ring 220 is rotated at the same rotational speed as the outer 
ring 215, the third gear 325 is specifically configured to have an 
appropriate number of gear teeth to provide for equal rotational speed. 
For example, if the first and second gears 315 and 320 are rotated at the 
same rotational speed as the drive gear 140, then the third gear 325 would 
preferably be configured to have one-tenth the number of gear teeth as the 
inner ring 220 thereby ensuring the outer ring 215 and inner ring 220 
rotate at the same speed. 
Returning to FIG. 3, the pallet 28 further includes gear engaging apertures 
340, 345 and 347 to allow for interaction between the drive gear 140 and 
outer ring 215, and between the outer ring 215 and the inner ring 220 via 
gear assembly 250. More particularly, the outer gear engaging aperture 340 
is defined along a periphery of the outer ring channel 290 and is sized to 
allow the drive gear 140 to engage with the outer gear teeth 230 of the 
outer ring 215. Furthermore, inner and outer gear assembly apertures 345 
and 347, respectively, are defined along an inner and outer periphery of 
the middle ring 300 and are each sized to allow the gear assembly 250 to 
engage with the outer ring 215 and inner ring 220. 
Referring back to FIG. 2, each pallet 28 further includes a lead lift 
assembly 350 for guiding the leads 50 to a desired position along end 
windings 35 during lacing. The lead lift assembly 350 includes ring 
portion 353 having a diameter just slightly larger than a diameter of the 
metal core 35 of the stator 25 such that the ring portion 353 may be 
freely lifted and lowered about the metal core 35. The ring portion 353 
further includes a pair of hooks 355a, 355b which define a stitch window 
360 through which lacing needle 69 reaches the end windings 35 during 
lacing. The ring portion 353 is movably secured to the pallet 28 via three 
lead lift legs 358. Each leg 358 includes a vertical section 361 and an 
angled section 363. Each angled section 363 is rigidly coupled to the ring 
portion 353 and is angled sufficiently to position the ring portion 353 
about the metal core 35. Each vertical section 361passes through a 
corresponding lead lift aperture 365 in the middle ring 300 of the pallet 
28. A spring 369 is secured to a distal end of each vertical section 
361using a lock nut 373. An opposite end of the spring 369 abuts an 
underside of the middle ring 300. The spring 369 provides a downward force 
on the lead lift assembly 350 to ensure that the lead lift assembly is 
lowered following a lacing procedure as discussed in more detail below. Of 
course, other means for aiding in lowering the lead lift assembly 350 such 
as placing weights on the distal end of the vertical section 361 
alternatively may be used. 
In operation, the present invention provides for an automated stator lacing 
process which minimizes the amount of operator intervention needed to lace 
the end windings 35 and leads 50 of the stator 25. More particularly, 
lacing of the end windings 35 and leads 50 is performed during an 
automated process which occurs while the stator 25 is situated on the 
pallet 28 during a manufacturing cycle. Thus, it is not necessary for an 
operator to lift the stator 25 from the pallet 28 and to place the stator 
25 over an arbor of a separate lacing machine. Furthermore, the automated 
lacing process automatically laces the end windings 35 and leads 50 of the 
stator 25 according to a predefined lacing pattern to ensure that the 
leads 50 extend from the end windings 35 at one or more desired locations 
without the need for an operator to manually guide the leads 50 during 
lacing. 
The stator 25 is placed on pallet 28 at a first station of a stator 
manufacturing facility at the start of a manufacturing process and is 
moved by the conveyer system 30 from one station to the next. In order to 
stabilize the stator 25 from movement, the metal core 33 is placed on the 
recessed step 279 of the inner ring 220. Additionally, in order to ensure 
that the stator 25 is not inadvertently rotated or moved by the inner ring 
220 upon which the stator 25 is situated, both the inner ring 220 and 
outer ring 215 are secured from rotational movement using spring loaded 
locking pin 216 (FIG. 2). The locking pin 216 is movably mounted to a 
lower portion of the platform 28 adjacent an area where the slidable gear 
assembly 140 engages with the outer ring 215. A spring (not shown) 
associated with the locking pin 216 provides sufficient force to engage 
the locking pin 216 between a pair of gear teeth on the outer ring 215 
when the slidable gear assembly 140 is not engaged. When the slidable gear 
assembly 130 is engaged, the traction plate 145 of the slidable gear 
assembly 130 engages with the locking pin 216 so as to move the locking 
pin 216 away from the gear teeth on the outer ring 215 thereby allowing 
for rotation of the inner ring 220 and outer ring 215 by the drive gear 
140. 
Referring now to FIGS. 1a, 1b, and 2, upon introduction of pallet 28 to the 
lacing station 20, the motor 146 provides motive force to the traction 
plate 145 to move the slidable gear assembly 130 towards the pallet 28 
until the drive gear 140 engages with the outer gear teeth 230 of the 
outer ring 215. Once engaged, the locking pin 216 unlocks the outer ring 
215 and inner ring 220 such that each may rotate about central axis A. 
Prior to lacing, the lacing needle 69 is automatically positioned to a 
predetermined position adjacent the stitch window 360 using motors 90 and 
78. Of course, an operator may adjust the placement of the lacing needle 
69 via an operator control panel (not shown) if desired. 
Referring now to FIGS. 7a-7f, an exemplary embodiment of the present 
invention is shown in which lacing of the end windings 35 and leads 50 
occurs such that the leads 50 ultimately extend from the end windings 35 
at two points spaced 180.degree. apart from one another. It will be 
appreciated that while FIGS. 7a-7f primarily focus on the end windings 35 
on the upper end 38a (FIG. 1a) of the metal core 33, the end windings 35 
on the lower end 38b of the metal core 33 are laced similarly by the 
lacing machine 21. Starting with FIG. 7a, stator 25 is shown situated on 
pallet 28 just prior to the beginning of a lacing process at lacing 
station 20. In this particular embodiment there is shown two sets of leads 
50, however, it will be appreciated that the stator 25 may include any 
number of sets of leads 50. 
As discussed above, each of the sets of leads 50 is pre-clipped to a 
corresponding clip 255 on the outer ring 215. The clips 255 provide 
tension to the leads 50 while still allowing the leads 50 to be pulled 
through the clip 255 when taken up during the lacing process. In order to 
ensure proper placement of the leads 50 during lacing, the vertical 
positioning device 165 (FIG. 2) raises the ring portion 353 of the lead 
lift assembly 350 prior to rotation of the stator 25. In order to raise 
the ring portion 353, the stepper motor 170 raises the lead lift plate 175 
such that the lead lift plate 175 engages the three legs 358 of the lead 
lift assembly 350. The lead lift plate 175 then lifts the ring portion 353 
via the legs 350 until the ring portion 353 is substantially flush with a 
top of the end windings 35 as depicted in FIG. 7a. As the ring portion 353 
of the lead lift assembly 350 is raised, a portion of the leads 50 are 
also lifted by the ring portion 353. Once the lead lift assembly 350 is 
raised, rotation of the stator 25 and lacing by the lacing needle 69 
begins. 
Referring now to FIG. 7b, the outer ring 215 and inner ring 220 are 
initially rotated 90.degree. in a counter clockwise direction. Rotation of 
the outer ring 215 is accomplished by way of the bidirectional motor 135 
rotating the drive gear 140 in a clockwise direction an appropriate number 
of revolutions. As discussed above, the gear assembly 250 provides for the 
outer ring to rotate the inner ring 220 an equal amount. During rotation, 
the lacing needle 69 is controlled via threading motor 95 and laces the 
end windings 35 and leads 50 which are presented to the stitch window 360. 
Because the stator 25 and clips 255 are rotated while the lead lift 
assembly 350 remains stationary, the hook 355a of the lead lift assembly 
350 catches the lead 50a and positions the lead 50a in the stitch window 
360 such that a portion of the lead 50a is laced to the end windings 35 as 
depicted by lead stitched portion 375a. The clips 255 facilitate the leads 
50 remain tense during the lacing process so that the leads 50 may be 
properly positioned by hooks 355. 
Next, as shown in FIG. 7c, the drive gear 140 rotates the outer and inner 
rings 215, 220, respectively, 180.degree. degrees in a clockwise 
direction. Again, during this rotation the lacing needle 69 continues to 
lace end windings 35 and leads 50 introduced to the stitch window 360. 
Thus, in this particular embodiment, the lacing needle 69 double stitches 
the end windings 35 and lead 50a in the region represented by lead 
stitched portion 375a during the first 90.degree. clockwise rotation and 
then continues to lace a new portion of the end windings 35 during the 
remaining 90.degree. clockwise rotation. 
Next, as shown in FIG. 7d, the lead lift assembly 350 is lowered by the 
vertical positioning device 165 by virtue of the stepper motor 170 
lowering the lead lift plate 175 (FIG. 2). Following lowering of the lead 
lift plate 175, the drive gear 140 rotates the stator 25 such that the 
stator 25 is rotated 180.degree. from its initial start point in FIG. 7a. 
During this rotation, the lacing needle 69 is not active. Following the 
180.degree. rotation, the lead lift assembly 350 is again raised by the 
stepper motor 170 such that the ring portion 353 is substantially flush 
with the top portion of the end windings 35. 
Referring now to FIG. 7e, the drive gear 140 again rotates the outer ring 
215 and inner ring 220 90.degree. in a counter-clockwise direction. During 
this rotation, the lacing needle 69 stitches the lead 50b to the end 
windings 35 along a region depicted by lead stitched portion 375b. 
Finally, as shown in FIG. 7f, the drive gear 140 rotates the outer ring 
215 and inner ring 220 in a 180.degree. clockwise direction. Similar to 
that described above with respect to FIG. 7c, during the first 90.degree. 
clockwise rotation the lacing needle 69 double stitches the end windings 
35 and leads 50b over the region depicted by lead stitched portion 375b. 
During the remaining 90.degree. degree rotation the lacing needle 69 
stitches the remaining end windings 35 introduced to the stitch window 
360. Following the final 180.degree. clockwise rotation, the lacing 
protocol is completed and the end windings 35 on both the upper end 38a 
and lower end 38b of the metal core 33 are laced about the entire 
360.degree. circumference of the metal core 33. 
It will be appreciated that the leads 50a, 50b are laced to the end 
windings 35 such that each set of leads 50a, 50b departs from the stator 
25 at a desired location which in the present embodiment is at opposite 
points along a circumference of the end windings 35. In some instances the 
points at which each set of leads 50a, 50b is configured to depart from 
the end windings 35 will correspond to one or more lead apertures 390 
predefined in a stator housing 400 as shown in FIG. 8. In this manner, the 
leads 50 remain easily accessible to an operator after the stator 25 has 
been placed into its housing 400. 
Following completion of the lacing protocol, the stepper motor 170 lowers 
the lead lift assembly 350 by lowering the lead lift plate 175. During 
lowering, the springs 373 (FIG. 2) also provide a downward force on the 
lead lift assembly 350 to facilitate proper retraction of the lead lift 
assembly 350. Finally, the slidable gear assembly 130 is retracted from 
the outer ring 220 using motor 146 and the locking pin 216 is engaged to 
facilitate the outer ring 215 and inner ring 220 not rotating as the 
pallet 28 is moved by the conveyer system 30 to the next station in the 
manufacturing cycle. 
While the present embodiment shows a stator 25 having two sets of leads 50a 
and 50b, it will be appreciated that if three or more sets of leads 50 
were included on the stator 25, all of the sets of leads 50 would still 
have departed from the stator 25 at one of the two points shown in FIG. 
7f. Furthermore, by rotating the stator 25 in both clockwise and counter 
clockwise directions and by resetting the stator positioning as shown with 
respect to FIG. 7g, the present embodiment provides for a lacing technique 
which reduces the area in which leads 50 overlap on the end windings 35 
during lacing. While overlapping of leads 50 during lacing does not affect 
the operations of the stator 25, it may in some instances provide the end 
windings 35 of the stator to have areas of higher or lower elevation 
thereby making it more difficult properly to fit the stator 25 in the 
stator housing 400. 
In an alternative embodiment of the present invention, it may be desirable 
to lace the end windings 35 and leads 50 such that the leads 50 all depart 
from the stator 25 at a single point. In such a case, the lacing protocol 
may, for example, be set to rotate the outer ring 215 and inner ring 220 
in a 360.degree. clockwise or counter clockwise direction while the lacing 
needle 69 laces in the stitch window 360. Alternatively, to reduce lead 50 
overlap on the end windings 35, the lacing protocol may rotate the stator 
25 180.degree. in a first direction, and then reset the stator 25 to its 
original position and then rotate the stator 180.degree. in the opposite 
direction. Similarly, a number of other lacing protocols may alternatively 
be used. 
In still another alternative embodiment of the present invention, it may be 
desired to have leads 50 depart from the stator 25 at three or more points 
about a circumference of the end windings 35. For example, if it were 
desired to have three depart points, the drive gear 140 may rotate the 
outer ring 215 and inner ring 220 in three 120.degree. rotations during 
which lacing by lacing needle 69 is reset between each 120.degree. 
rotation to provide for three lead depart points. Similarly, if four or 
more depart points were desired, the drive gear 140 and lacing needle 69 
may be configured appropriately to rotate and to lace the end windings 35 
and leads 50 as needed. It will be appreciated that the present invention 
is intended to cover all such lacing protocols. 
The invention has been described with reference to the preferred 
embodiments. Obviously, modifications and alterations will occur to others 
upon reading and understanding the preceding detailed description. For 
example, while the above embodiments show the ring portion 353 of the lead 
lift assembly 350 to include only one pair of hooks 355 defining a single 
stitch window 360, it will be appreciated that the lead lift assembly 350 
may include additional hooks 355 defining multiple stitch windows. 
Further, while the above embodiments show a single drive gear 140 to drive 
both the outer ring 215 and inner ring 220, it will be appreciated that 
separate drive gears could alternatively be used for each of the rings 
215, 220. It is intended that the invention be construed as including all 
such modifications alterations, and equivalents thereof.