Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
03-AO-5173
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The present invention relates generally to apparatus and
methods for making slot closure wedges for magnetic stator
cores at a station where coils and wedges are axially
injected into axial slots of such cores; and more particularly
where such wedges are formed into a desired shape by rollers
and fed by pinch roller action to a wedge cutting mechanism
adjacent to a wedge magazine that is disposed generally
collinearly with axially extending coil injection tools.
Numerous patents in the art illustrate methods and
apparatus whereinwedges are made in a wedge maker, placed
in a wedge magazine disposed generally collinear with
axially extending coil injection blades or tools, and
wherein the wedges subsequently are inserted axially into
stator core slots along the trailing ends of stator coils
that are also being axially inserted into such slots. The
wedges then lie between side turn portions of the slots
and the stator bore, and sometimes lie adjacent the bore
and effectively "close" such slots. Morr U.S. patent
No. 3,872,568 which issued March 25, 1975 is one patent
which illustrates an arrangement as just described, and
further general background information is supplied at
lines 1-50 of column 1 of this patent.
Another patent which pertains to this art is Eminger
U.S. patent 3,447,225 which issued June 3, 1969. This
particular patent recognizes a problem that has become
known in the art as the "wire over wedge" problem. This
particular problem has continued to trouble the industry,
and the inventions described in the present application are
intended, among other things, to solve this problem.
Still other patents that illustrate apparatus of the
type to which the present invention may be applied are
Hill U.S. patent No. 3,324,536 of June 13, 1967; Lauer et al
.~
-- 1 ~
03-AO-5173
llS3538
U.S. patent No. 3,829,953 of August 20, 1974; Arnold et al
U.S. patent 3,579,818 of May 25, 1971, and Smith et al
U.S. patent 3,831,255 of August 27, 1974.
Apparatus embodying the present invention in one
preferred form differs from the prior art mentioned
hereinabove at least in that wedge material is selectively
fed by a pinch wheel arrangement that serves both as a
feeding mechanism and as a means for forming wedge material
into a predetermined shape, and in that the wedge material
is substantially immediately thereafter served into
individual wedges and then inserted into a wedge magazine.
Shortely thereafter, e.g., within one machine injection
cycle, the wedges are axially placed in core slots.
Peters U.S. patent 3,805,357 of April 23, 1974
illustrates a pinch wheel feed arrangement for stator core
wedge material which is formed into wedges by a wedge
forming die spaced from the pinch wheel feed mechanism.
Peters U.S. patent 3,909,902 of October 7, 1975 also
shows a pinch wheel feed mechanism for insulating material
(best seen in FIG. 5 of the patent), but in the context
of a non-analogous ground insulation cell inserting machine
rather than a wedge maker; Ott U.S. patent No. 3,758,937
of September 18, 1973 shows a pinch wheel feed wedge inserter
for the non-analogous armature art.
Machine Products Corporation of Dayton, Ohio has sold,
more than a year prior to this application, a pinch wheel
fed stator wedge maker which forms wedges which ultimately
are placed in slots or cores that have previously had
windings placed therein; and Lakes Engineering of Bluffton,
Indiana has, more than a year prior to the filing date
of this application, sold what is known as a "hot former
mylar wedge maker". However, the two machines just mentioned
03-AO-5173
llS3S38
are sold for making wedges per se, and the present invention
is directed to the solution of problems encountered in
apparatus of the type wherein wedge making and wedge
insertion is accomplished with the same equipment that is
utilized for stator coil "injection" (or "placing" as it
is sometimes called in the art).
In the prior art equipment of the type where wedge
making and insertion mechanisms are combined with coil
injection mechanisms, the wedge material most typically
is advanced with a "hitch" feed as shown for example in
FIG. 2 of the above referenced U.S. patent No. 3,579,818.
Moreover, in equipment of this combined function type, the
wedges themselves are formed by dies which include a die
movable transversely to the direction in which the wedge
material is being fed. Very often, such movable die also
places the wedge in the wedge magazine. The wedges so made
are placed in a magazine and the, as winding sideturn
portions of coils are moved from the tooling of the combined
function equipment and axially into axially extending slots
of a stator core, the wedges are axially advanced immediately
behind the winding side turn portions. It is intended,
with all such equipment, that all of the side turn portions
being inserted in a given slot be positioned "under" the
following wedge being placed in the same slot. In other
words, none of such winding turn portions (or segments
thereof) should be "over" the wedge and thus lie between the
wedge and the bore of the stator.
However, experience has shown th~t the wire over wedge
problem has persisted, despite efforts to overcome the
problem. Moreover, the wedge material feeding and forming
apparatus of the prior art machines has been relatively
complex and thus relatively difficult to make and maintain,
03-AO-5173
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and especially so when provision must be made for "skipping"
predetermined wedges.
It thus should be understood that it would be desirable
to provide new and improved combined function methods and
apparatus for wedge making and inserting and coil injecting
that overcome the above-mentioned problems.
Accordingly, it is an object of the present invention
to provide new and improved methods and apparatus for
making and inserting stator core wedges, and for inserting
windings into axially extending slots of a stator core that
open into an axially extending bore.
A more specific object of the present invention is to
provide apparatus and methods whereby wedges are precisely
dimensioned, and substantially immediately placed in a
wedge magazine and placed in slots of a core without re-
laxation of the wedge dimensions, whereby wire over wedge
problems are alleviated.
Still another object of the invention is to provide
new and improved apparatus and methods that satisfy the
objects started hereinabove, and yet wherein the manufacture
of wedges may be performed or omitted in preselected patterns.
In carrying out the above and other objects of the
present invention, improved apparatus is provided which, in
one preferred form, includes means that both advance wedge
material stock and also substantially permanently form the
stock material to precise dimensional tolerances; means by
which the formed material is retained in the formed con-
figuration thereof; wedge severing means; and means for
loading severed wedges into a wedge magazine. In one
form of apparatus, the wedge magazine comprises the lower
tooling of a coil injection machine and forms, in effect,
an extension of tool gaps that accommodate winding coils
in a coil injection machine. However, the magazine receiving
03-Ao 5173
~lS353~3
the wedges may be a short term storage magazine which in turn
feeds the wedges to a wedge magazine that forms the lower
tooling of a coil injection machine. Thus, embodiments of
the present invention are of primary use and benefit in
multifunction machines. "Multifunction machines" is meant
to denote machines that perform the multiple functions of:
making wedges for stator cores, inserting coils of winding
turns into stator cores, and placing the wedges in at least
selected slots of a stator core.
The means that both advance wedge material stock and
also substantially permanently forms the stock material
preferably comprise a pair of pinch wheels or rollers
that pinch the stock therebetween at preselected times in
order to feed wedge material. One of the wheels is driven
through a clutch-brake system arranged so that it may be
driven unidirectionally only from a reciprocating drive arm.
The other wheel is supported so that it may be selectively
urged toward the first wheel in order to pinch and feed wedge
stock material. In addition, the wheels or rollers are
contoured and dlmensioned so that wedge material being
rolled therebetween will be formed into a desired con-
figuration. The forming of the wedge material by the
wheels results in wedges having precisely controlled
dimensional tolerances and dimensional stability, with the
result that the wedges lie squarely in stator core slots
in stator core slots (when the wedges are inserted into
such slots~, and "wire over wedge" problems associated
with skewed wedges in stator core slots are overcome.
In this regard, it should be understood that wire over
wedge problems can be aggravated when non-symmetrical
wedges, e.g., wedges having legs of unequal length or legs
bent at different angles are positioned in stator core slots
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which have symmetrical interior walls and/or tooth tips
relative to a centerline passing generally radially along
the slot. This problem results since a non-symmetrical
wedge will tent to "twist" as it moves to its final
position in the slot, and one or more wire segments may
become positioned "over" the wedge (i.e., become
positioned between the wedge and the bore of the core).
The subject matter which I regard as my invention is
particularly pointed out and distinctly claimed in the
concluding portion of this specification. The invention
itself, however, taken with further objects and advantages
thereof, may be best understood by reference to the following
description taken in conjunction with the accompanying
drawings.
FIG. 1 is a side elevation, with parts removed, parts
in section, and parts broken away, of a wedge making, and
wedge and coil injection machine particularly adapted for
use in the manufacture of dynamoelectric machine stators;
FIG. 2 is a view taken in the direction of lines
2-2 in FIG. 1, but wherein some par-ts are removed and some
parts are broken away for clarity of illustration;
FIG. 3 is a view taken in the direction of lines 3-3
in FIG. 1, but wherein parts are removed and broken away
to promote clarity of illustration;
FIG. 4 is an enlarged view of a portion of the pinch
feed and forming wheels shown in FIGS. 1-3; and
FIG. 5 is an enlarged view of a portion of the
structure denoted by a broken line circle in FIG. 4.
Referring now to the drawings, and particularly to
FIG. 1, a multifunction machine 20 has been illustrated
which is a wedge making and wedge and coil injection
machine of the type shown in the above referenced Lauer et al
-- 6
03-AO-5173
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U.S. patent 3,829,953; Morr U.S. patent 3,872,568; Eminger
U.S. patent 3,447,225; Hill U.S. patent 3,324,536; and so
on. For clarity of illustration, portions of the apparatus
20 not necessary for an understanding of the present
improvements have been omitted, but the relationship of
the structure actually shown in FIGS. 1 and 3 hereof to the
not shown parts of apparatus 20 can be readily appreciated
by comparing the structure shown in FIGS. 1 and 2 herein
with the disclosures in the above referenced patents. For
example, the wedge magazine 21, hook 22, and ratchet teeth
23 shown in FIGS. 1 and 2 correspond with the hook or
ratchet mechanism 104, ratchet teeth 23, and wedge magazine
96 shown in FIG. 6 of Eminger patent 3,447,225. Other
similarities between Eminger's "slot wedge forming and
loading apparatus 113" and the corresponding structure
shown by applicant will also of course be appreciated by
persons of ordinary skill in the art. One of the differences
between Eminger's arrangement and that of FIG. 1 herein
which should be emphasized is that wedges are "formed" by
20 Eminger's "punch member 170", while the blade 24 used herein
only pushes wedges into slots 26 of the magazine 22,
because the wedges themselves are "formed" by a forming
and feeding pinch wheel arrangement described in more
detail hereinbelow. It is also noted that, while the
ratchet teeth 23 and pawl or hook 22 is shown at the lower
end of the wedge magazine 21 in FIG. l; the ratchet
mechanism could just as well be located at the upper end
of the magazine 21 in the manner described at lines 24-34
in column 3 of the referenced Hill U.S. patent No. 3,324,536.
Although the patents to Emin~jer and Hill have just
been specifically referred to, it will be understood that
the relationship of the structure illustrated by the drawings
1~53538 03-AO-5173
herein is also related to the structures il]ustrated in the
other hereinabove referenced patents. For example, the
correspondence between the "wedge maker 112", "wedge magazine
86" and "index ratchet 92" of Morr U.S. patent 3,872,568;
the "wedge magazine 220", "ratchet plate 212", and "pawl
214" (hook) of Arnold et al U.S. patent 3,579,818; and the
wedge magazine 21, ratchet teeth 23, and hook or pawl 22,
all as shown herein, is self-evident.
With more specific reference now to FIG. 1 herein,
it is noted that although the specific orientation of the
apparatus there shown relative to a horizontal plane is
not critical; in preferred exemplifications the rotational
axis 27 of the magazine 21 (and thus the central longitudinal
axis of the not shown coil injection tooling) is oriented
at approximately forty to forty-five degrees relative to
horizontal (a relative orientation similar to this is
shown in FIG. 1 of Fohl U.S. patent No. 3,626,432, dated
December 7, 1971). However, the apparatus 20 has been
oriented in FIG. 1 with the magazine and tooling oriented
horizontally in order to illustrate the apparatus to as
large a scale as possible.
Strip insulating material 28, which typically is a
polyester material, is fed into the apparatus 20 from the
left as viewed in FIG. 1. The polyester material suitable
for use as insulating material in dynamoelectric machine
stator cores is sold under various trade names. However,
material that has been utilized while practicing the present
invention has been material sold commercially by the
E.I. DuPont de Nemours and Company as MYLAR insulating
material. As is well known, M~'LAR material is a polyester
material known as polyethylene terephalate.
The material 28 is pulled into a track established
8 -
; -,.~ ~
03-AO-5173
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by a guide 29 and a cover 31 by the co-action of an upper
forming roller 32 and a lower forming roller 33. Although
the term "roller" will be used herein to describe the
elements 32 and 33, it should be understood that other
terminology such as a "forming wheel" or "pinch wheel"
could also be utilized.
The material 28 is formed to have a predetermined
configuration having precise dimensional characteristics
that are determined by the peripheral contours of the
forming or pinch rollers 32, 33. The insulating material
so formed then is pushed by the rollers along another
trackway that is defined by the guide 34 and cover 36.
The guide 36 and cover 34 in turn terminate at a stationary
guide area defined by a lower plate 37 and upper cover 38.
It will be understood that the cover 38 and guide 37 also
define a trackway or pathway having a cross-sectional
configuration corresponding to the desired configuration
of the insulating material which was established by the
forming rollers 32, 33. Continued operation of the forming
rollers 32, 33 cause the formed insulating material to
advance from between the cover 38 and guide 37 and move
to the end of a track that is established by a lower guide
plate 39 (best seen in FIG.2) and a pair of spacer plates
41 (also best seen in FIG. 2).
As will be best appreciated from an inspection of
FIG. 2, the guide plate 39 and spacer plates 42 also are
formed to have a cross-sectional configuration which will
accept the previously formed insulating strip material.
The apparatus 20 operates so that the preformed
strip material is advanced beyond the end of the trackway
defined by the cover 38 and guide 37 a distance generally
corresponding to the axial length or height of the stator
03-AO-5173
11~3~38
core into which the insulating material 28 is -to be inserted
in the form of discrete individual wedges. The end of
the trackway defined by cover 38 and guide 37 defines the
active location of a cutoff mechanisms which includes a
cutoff blade 42 (see FIG. 2~, a blade carrier 43, and blade
actuating arm 44 to the end of which is fastened a cam
follower 46. The cutoff mechanism just described is known
in the art and formed part of the basic apparatus 20 before
it was modified to embody the present invention. However,
the various guides 29, 34, 37 and guide plates 39 are novel
in the apparatus 20 as are the covers 31, 36, 38, and
spacers 42 to the extent that they define a trackway that
is formed to have a shape that corresponds to the shape of
the formed insulating strip material 28. Before being
modified to embody features of this invention, the feeding
mechanism for the apparatus 20 was quite similar to that
shown in FIG. 2 of the above-referenced Arnold et al U.S.
patent No. 3,579,818. In the Arnold patent, a hitch feed
mechanism was utilized to feed insulating material while
in a flat configuration past the cutoff mechanism at which
time the flat material was cut off and then inserted into
the wedge magazine 21. The insertion mechanism of the
apparatus 20 is not modified from the prior art and thus
the inserter slide 47, and inserter blade 24 shown herein
have been known and used (prior to the present invention)
in the same form that they appear in the drawings. Thus,
in summary, novel modifications of the apparatus 20 so that
it would embody the present invention include the provision
of the forming rollers 32, 33 (along with their associated
control and drive mechanisms), and the specially configured
trackway defined by the covers 36, 38 and guides 34, 37.
The drive for the forming roller 32 is derived from a
-- 10 --
03~AO-5173
~5;~53~
cam assembly generally denoted by the reference numeral 49.
The drive from the cam assembly is then applied through
arm 51 to a wrist pin 52 and thence to an arm 53. The
arm 53 in turn is tied to a clutch 54, best seen in FIG. 3,
and the clutch then rotates shaft 55 to which upper
forming rollers 32 is keyed for rotation. As best revealed
in FIG. 3, the shaft 55 is supported for rotation by a
bearing 56 carried by a mounting plate 57 and a bearing which
is carried in a bearing retainer 58. The bearing retainer
58 in turn is supported by main frame member 58 and a lock
nut 59 and bearing retainer washer 61 cooperate to hold
the shaft 55 in the desired assembled relationship with
the mounting plate 57 and main frame member 60.
With continued reference to FIG. 3; a support bracket
62 is welded at one end thereof to main frame member 60.
The bracket 62 serves to support a braking means that
includes brake bracket 63, and also to support the
previously mentioned mounting plate 57 which is fastened
thereto by screws 64. The brake bracket 63 is fastened by
screws 66 to bracket 62, and is bifurcated as illustrated
so as to straddle a portion of upper roller 32. The
bifurcated portions of bracket 63 are bored and tapped as
illustrated so as to accommodate two socket head cap
screws 67, a pair of springs 68, and a ~air of brake plugs
or pads 69. The springs 68 are trapped between the screws
67 and plugs 69, with the result that the plugs 69 are
spring biased against opposite faces of roller 32. The
plugs 69 thus continuously frictionally engage roller 32
and apply a braking force thereto. While any suitable
material may be used to make brake plugs 69, satisfactory
results have been obtained by using plugs made from
TEXTOLITE material (marketed under that name by the
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General Electric Company) that were 9.53 mm long (3/8 inch)
and 7.92 mm (~.312 inches) in diameter.
The function of the just described braking means is to
insure that upper forming roller 32 will not move except
when it is being positively driven by clutch 54.
Clutch 54 was a purchased FORMSPRAG clutch model
FSR5 having a bore of 15.88 mm (0.625 inches), and left hand
rotation. This clutch transmits driving power to shaft
55 only when driven in one direction, and slips when driving
power tending to cause reverse rotation is applied thereto.
Thus, with reference to FIG. 1, as arm 51 reciprocates
as indicated by arrows 71, roller 32 will intermittently
rotate in the direction indicated by arrow 72, with the
reciprocating or oscillating motion of arm 51 being
converted to periodic rotary motion by means of wrist
pin 52, and one-way clutch 54. For purposes of safety,
guards 73 are provided around upper roller 32, although
the use of such guards would usually be optional
With reference now to FIG. 3, lower forming roller
33 is rotatably supported on a pair of bearings 76 which
in turn are supported by a cap screw 78. The screw 78
passes through a bore 81 in a bifurcation 77 and is
retained by threads in a tapped portion 82 of a bifurcation
79. Actually, the bifurcations are bifurcated portions of
a lower pulley supporting arm 83, as will be evident from
a comparision of FIGS. 3 and 1.
As best revealed in FIG. 1, a bifurcated mounting
block 84 is welded to main frame member 60i and one end
88 of arm 83 as well as one end 87 of a hydraulic cylinder
86 are secured in the bifurcation of block 84 by pivot
pins 89, 91. The rod 92 of cylinder 86 is threaded
into a tubular adapter 93, and adapter 93 in turn is
- 12 -
03-AO-5173
~lS3538
pivotally connected with first ends of two links 94, 96 by
means of a pin 97. Since the other end of link 96 is
supported on a fixed pivot pin 98 carried by a bifurcated
block 99 welded to frame 60; and the other end of link
94 is pivotally connected to the bifurcated end of arm
83 at 101; a toggle linkage is provided whereby arm 83
will move lower forming roller 33 toward and away from
upper forming roller 32 in response to movement of
cylinder rod 92.
Thus, when rod 92 retracts, arm 83 will swing
downwardly (at least as viewed in FIG. 1) roller 33 will
move away from roller 32, and material 28 will not be
pinched between the two rollers. Because of this, a
segment of material 28 will not be advanced from guide 29
to guide 34 even though roller 32 is rotated. Thus,
cylinder 86 is useful for determining whether or not a
wedge will actually be placed in any given slot 26 (see
FIG. 2) of wedge magazine 21. Furthermore, cylinder 86,
in conjunction with adjustable stop means 102, will
determine the degree of proximity with which roller 33
will be held to roller 32. This degree of proximity in
turn will determine how tightly a given thickness of
material 28 will be pinched between the rollers and is
particularly advantageous for reasons enumerated herein-
below.
It will be appreciated that the illustrated adjustable
stop means 102 comprises a socket head cap screw 103
threaded into block 104 and jam or lock nut 106. The
block 104 is securely fixed to frame 20, e.g., by welds
or screws; and when welded as shown, it is preferred that
a locating dowel 107 be used to insure proper location of
the block on frame member 60. With the arrangement just
- 13 -
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described, screw 103 may be extended or retracted in order
to limit the length of travel of rod 92, and thus determine
the degree of expansion of the toggle linkage, all as should
now be fully understood.
With reference now to FIG. 2 in conjunction with
FIG. 1, the operation of the wedge inserter mechanism and
wedge cut-off mechanism, wedge magazine ratcheting
mechanism, and, wedge maker driving mechanism, (all of
which have been known by others prior to the present
invention will be explained.
Motive power for the cam assembly 49 is supplied
from a drive sprocket 108 mounted on a hydraulic motor
(see FIG. 1) through a chain 109 to a driven sprocket 111
(see FIG. 2). As will be best understood from FIG. 2, the
sprocket 111 is keyed or otherwise fastened to a cam shaft
112 which is drivingly connected with the cam assembly 49
which includes a number of cams that rotate together.
I'he cam assembly 49 in turn includes a face cam 113
which drives cam follower 114 and thereby controls the
movement of the inserter slide 47 to which inserter blade
24 is attached. As the cam 113 rotates for one revolution,
the follower 114 rides in track 116, and blade 24 undergoes
one reciprocation. The blade thus acts to transfer to a
wedge magazine slot 26 any severed wedge positioned in the
path of travel of the blade 24.
The cam follower 46, forming part of the wedge cut-
off mechanism, is constrained to follow the outer peri-
pheral cam surface of cam 113 (see FIG. 1) by the action
of tension spring 117 which is stretched between a re-
30 tainer 118 on actuating arm 44 and a retainer 110 mounted
on guide block 121. Thus, one revolution of cam 113 will
cause one reciprocation of cut-off blade 42, and any wedge
03-AO-5173
1153538
segment positioned under the cut-off blade will be severed.
With reference now again to FIG. 2, a mounting block
122, welded to frame 60, has bolted thereto a pivot plate
123. The plate 123 in turn pivotally supports, at pivot
124, a link assembly 126 (see FIG. 1) which carries a cam
follower 127 and a ball joint 128 to which a spring holder
129 is attached. A tension spring 131 is stretched
between the spring holder 129 and a slide bar support 130
which is held in a stationary positioned by reason of its
attachment (by welding, bolting, etc.) to part of the
frame 60 (see FIG. 1). With this arrangement, the cam
follower 127 is constantly urged downwardly against the
outer peripheral surface of cam 132 which forms part of
the cam assembly 49. One revolution of the cam assembly
49 causes one reciprocation of link assembly 127 and the
rotary advancement of wedge magazine 23 an amount
equivalent to the spacing between adjacent slots 26
(see E'IG. 2).
As will be understood from FIG. 2, a link 133 is
connected to the ball joint 128 and a lower ball joint
134 carried on the upper end of a slide bar 136 which is
constrained to move up and down in a linear path by the
slide bar support 130. The lower end of slide bar 136 is
bifurcated (see FIG. 1) and bored to receive a compression
spring 137 and button 138 (see FIG. 2). The pawl or hook
22 is held in the bifurcated end of the slide bar by dowel
pin 139, and the pawl serves as a retainer for the button
138 and spring 137.
In view of the foregoing, it will be understood
that the pawl 22 and teeth 23 (of the wedge magazine)
coact to form a wedge advancing ratchet mechanism as the
link assembly 126 (see FIG. 1) drives the link 133, slide
03-AO-5173
1~5~538
bar 136, and pawl hook 22.
Cam 141 also forms par-t of the cam assembly 49, and
this cam drives a cam follower 142 which periodically
activates a limit switch 143. A cam similar to cam 141
could be provided to actuate a limit switch similar to
limit switch 143 so that the limit switch could close
just prior to the time that arm 51 starts to advance roller
32 in the direction of arrow 72. The signal from such
switch then could be fed to a control circuit which, as
will be understood by persons skilled in the art, would be
programmed to determined the "pattern" of wedges desired.
If the wedge that would otherwise be made is to be
"skipped" or omitted, the control circuit then would cause
hydraulic cylinder 86 to retract and collapse toggle links
94. This in turn would withdraw roller 33 and disable
advancement of wedge material 28 for that particular sub-
cycle of the equipment. Thus, a cam and limit switch
could provide a signal as to "when" toggle links 94 should
be collapsed, while the general controller for the apparatus
would determine "whether" the links should collapse and
thus "skip" a wedge. On the other hand, any of the wedge
pattern controllers currently used in the industry to
"skip" a wedge by disabliny a wedge material feeding
mechanism (e.g., a "hitch feed"), could be used to control
the condition of cylinder 86.
In the apparatus illustrated in FIG. 1, the cam 141
and limit switch 143 are actually used to indicate a "safe
to inject" condition of the wedge maker. In other words,
the cam follower 142 will be on the high lobe of cam 141
only during the time that inserter blade 24 (see FIG. 2)
is not in an interfering relation with a slot of the wedge
magazine 21.
- 16 -
03-AO-5173
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A limit switch 144 i5 triggered by a lobe 146 on cam
147 once during each revolution of sprocket 108 (and thus
once each revolution of cam assembly 49), and the switch
144 thus provides a signal each time the wedge magazine
21 is advanced one slot or "step". This signal is then
utilized in the counter portion of the main control which
is used to establish the number of wedges actually made
in a given wedge making cycleO This signal of course also
could be used when determining which wedges are to be
"skipped". The main control of course is used to disable
the wedge maker once the magazine 21 is loaded (i.e., once
it has been advanced 24 slots if its contains 24 slots,
etc.l-
Although the apparatus illustrated herein has beendescribed in conjunction with a wedge magazine that forms
the lower part of the tooling package for the equipment,
it is to be understood that the wedge feeder and maker
described herein could also be used to load wedges into a
wedge transfer magazine from whence a full set of wedges
would be virtually simultaneously transferred into a
magazine such as magazine 21 (which forms part of the
tooling package of a coil injection machine).
The reciprocating driving action imparted to arm
51 is derived from the rotary motion of cam assembly 49 by
means of a slider mechanism that includes a pivot pin
148 carried by slider 149, and guide block 151 which is
fastened to cam 141 by means of four socket head cap screws
152. During one complete revolution of cam assembly 49,
arm 51 will undergo one reciprocation, and the upper
forming roller 32 will be driven in the direction of arrow
72 while arm 51 moves toward the right (as viewed in FIG.
1.1). On the other hand, due to the type of clutch used
- 17 -
03-AO~5173
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and the previously described brake (clutch 54, brake plugs 69,
see FIG. 3), roller 32 will remain stationary during that
part of the reciprocation that arm 51 is moving to the left
(as viewed in FIG. 1). The slider 149 is held in fixed
relation to guide block 151 during normal operation of the
apparatus by socket head cap screw 153. Thus, slider 149
does not normally move relative to guide block 151.
However, when it is desired to change the length of wedges
being produced, the position of slider 149 within the slot
of guide block 151 is adjusted by turning screw 153 ana
this in turn adjusts the distance between the center of
pin 148 and the center of cam assembly 49. In this manner,
the effective "crank arm" dimension of the slider mechanism
is changed, thus causing a proportional change in the
actual amount of rotation of roller 32 during each "wedge
material advance" operation of roller 32. Of course, prior
to adjustment of screw 153, screws 154 in wrist pin 52 are
loosened temporarily so that the effective length of arm
51 will also be adjusted. A close inspection of FIG. 1
will reveal that screw 153 is threaded into slider 149, and
that the head of screw 153 is trapped by a cap portion of
guide block 151 so that axial movement between screw 153
and guide block 151 is prevented (although rotation of
screw 153 relative to guide block 151 is permitted).
With reference now to FIGS. 4 and 5, some of the
advantages of using the illustrated apparatus will be
described. With initial reference to FIG. 4, the rollers
32, 33 co-act to pinch together the strip material and
form (i.e., permanently stress) the strip material at
predetermined regions so that it will assume a predeter-
mined desired cross-sectional configuration or shape as
shown in FIG. 4. More specifically, this shape is
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symmetrical relative to the central reference plane 156,
with the legs 157, 158 being of the same length within
close dimensional tolerances (as compared to shapes formed
merely by the action of a blade and die at a wedge magazine
loading station as shown, for example, in FIG. 2 of the
above-referenced Arnold et al U.S. patent 3,579,818 or
in FIG. 6 of the above-referenced Eminger U.S. patent
No. 3,447,225).
The precise dimensional tolerances of the wedge material
shape shown in FIG. 4 is attained because the guide 29 of
FIG. 1 is accurately aligned with rollers 32, 33 to insure
that the material 28 will be transversely centered relative
to the reference plane 56 shown in FIG. 4. Since the
strip material 28 is tightly pinched between the rollers
32, 33, the material 28 continues to be centered relative
to the plane 156 as it is deformed and permanently stressed
by the pinching action of the rollers.
It was mentioned hereinabove that the expanding
action of the toggle links 94 (shown in FIG. 1) was
adjustable in order to control the degree of proximity
of the rollers 32, 33. It has now been determined that the
rollers 32 and 33 should be positioned sufficiently close to
one another so that the strip material is permanently
stressed by reducing its dimension in the vicinity of the
corners 161, 162. In addition, the roller 33 is crowned
relative to the reference plane 156 so that the central
portion 163 of the wedge material 28 is stressed.
The dimensions of the rollers 32 and 33 may be closely
established by conventional machining and manufacturing
methods and, thus, location of the portions of the rollers
that establish the corners 161, 162 of the wedge material
can be precisely established (within normal machining
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tolerances). Stationary results have been obtained using
the apparatus illustrated herein when producing wedges
from MYLAR material having a thickness of about 0.355mm
(0.014 inches) when the proximity between rollers 32 and
33 has been adjusted so that the final reduced dimension
of the MYLAR material at the corners 161, 162 had a reduced
thickness dimension t (see FIG. 5) of about 0.254mm
(0.010 inches). Once the wedge material has been deformed
at the corners 161, 162 as just described, the location
of the corners is essentially permanently established.
Thus, when the wedge material is severed and inserted
as individual wedges into the wedge magazine, symmetry
of the wedges relative to the reference plane 156 is
assured and continuing symmetry of the wedges as they are
inserted into stator core slots is assured. It is
believed that this assured symmetrical configuration of
the wedges substantially contributes to avoidance of the
wire over wedge problems discussed hereinabove in the
section of this application identiied as the background
for the present invention.
It should be understood that materials obtained
from different sources which are to be used as wedge
material, and that materials of initial dimensions other
than that described hereinabove for the material 28, may
require adjustment of adjusting screw 103 (see FIG. 1) so
that the degree of proximity of the rollers 32 and 33 will
be adjusted accordingly. In other words, while suitable
results have been obtained by establishing the dimension t
as approximately a 29% reduction from the initial thickness
of the strip material 28 (when it is MYLAR material of the
thickness mentioned) other per cent reductions in thickness
may be more optimum for materials of different thickness
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or for materials obtained from other sources. The apparatus
shown herein insures that simple and rapid adjustment may
be made to the equipment in order to insure continued high
volume production usage of the equipment without being
burdened by continuing wire over wedge problems.
With reference particularly to FIGS. 4 and 5, it
will be noted that the corners 164, 165 of roller 32 are
radiused slightly. The exact dimensions of such radius (and
the corresponding radiused portions of roller 33) are not
critical, and those parts of the rollers are radiused simply
to insure that sharp corners are not provided which might
cut through the insulating strip material and actually
sever it rather than merely compress and reduce the
dimension of the material at the compression point.
While the present invention has been explained by
describing a preferred embodiment thereof, and some modification
thereto, it should be apparent that many modifications may
be made when actually putting the invention into practice
without departing from the spirit of the invention. It is
therefore intended to cover all such equivalent variations
as come within the scope of the appended claims.
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