U.S. patent number 3,719,212 [Application Number 04/793,921] was granted by the patent office on 1973-03-06 for circular weaving apparatus product and process.
This patent grant is currently assigned to Monsanto Company. Invention is credited to Charles E. Barter, S. Jack Davis, Paul D. Emerson, Fred H. Engelman, John C. Oakfield.
United States Patent |
3,719,212 |
Emerson , et al. |
March 6, 1973 |
**Please see images for:
( Certificate of Correction ) ** |
CIRCULAR WEAVING APPARATUS PRODUCT AND PROCESS
Abstract
A thick-walled, integrally woven, three-dimensionally shaped
fabric which is produced on a circular type weaving machine is
comprised of a plurality of yarn systems each of which defines a
plurality of yarn planes with the yarn planes of each yarn system
being distinct and traversing selected yarn planes of the other
yarn systems. The fabric is woven upon the surface of a mandrel
with the resulting shape being determined by the action of Jacquard
means on the yarn systems and by the three-dimensional shape of the
mandrel. The resulting fabric may be woven in the shape of a
cylinder, a truncated cone, or as irregular shapes, such as, an
airplane wing, a boat hull or the like.
Inventors: |
Emerson; Paul D. (Raleigh,
NC), Davis; S. Jack (Chapel Hill, NC), Oakfield; John
C. (Cary, NC), Engelman; Fred H. (Cary, NC), Barter;
Charles E. (Durham, NC) |
Assignee: |
Monsanto Company (St. Louis,
MO)
|
Family
ID: |
25161158 |
Appl.
No.: |
04/793,921 |
Filed: |
December 31, 1968 |
Current U.S.
Class: |
139/387R |
Current CPC
Class: |
D03D
3/00 (20130101) |
Current International
Class: |
D03D
3/00 (20060101); D03d 003/02 () |
Field of
Search: |
;139/383,384,387,388,408-415 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Jaudon; Henry S.
Claims
We claim:
1. A thick-walled, seamless and tubular article comprising an
integrally woven fabric being woven about a given axis, said fabric
comprising locker warp yarn systems and a continuous helical
filling yarn system, said filling yarn system comprised of
continuous filling yarns forming a plurality of annular and
substantially parallel yarn planes being concentric and coextensive
with said axis and said locker warp yarn systems comprised of
locker warp yarns forming locker warp yarn planes arranged
coextensively and radially with respect to said axis, said locker
warp yarns within a given one of said locker warp yarn planes
traversing a plurality of said filling yarn planes and locking said
filling yarns together by following a predetermined sinuous
path.
2. A thick walled article comprising an integrally woven thick
fabric, said fabric being woven in the configuration of a
predetermined three-dimensional form and comprising first, second
and third yarn systems positioned about a reference axis, said
first yarn system being comprised of locker warp yarns forming
locker warp yarn planes arranged coextensively and radially with
respect to said axis, said second yarn system being comprised of
filling yarns forming filling yarn planes arranged concentrically
and coextensively with said axis, said locker warp yarns within a
given one of said locker warp yarn planes traversing a plurality of
said filling yarn planes and locking said filling yarns together by
following a predetermined sinuous path and said third yarn system
being comprised of stuffer yarns forming stuffer yarn planes
arranged coextensively and radially with respect to said axis, said
stuffer yarn planes traversing a plurality of said filling yarn
planes.
3. The thick-walled articles of claim 2 wherein said yarn planes
occupied by said locker yarns sequentially alternate with said yarn
planes formed by said stuffer yarns.
4. The thick-walled article of claim 2 wherein said
three-dimensional shaped is continued uninterruptedly about the
said axis.
5. The thick-walled article of claim 4 wherein the individual picks
of said filling yarns lie in yarn planes normal to said axis, said
yarn planes being substantially parallel to each other.
6. The thick-walled article of claim 5 wherein said locker warp
yarn planes and said stuffer warp yarn planes are radially arranged
with respect to and include said axis.
7. The thick-walled article of claim 6 wherein the angle between a
plane which is tangent to the surface of said thick-walled article
and the said axis of the said thick-walled article is greater than
0 degrees and less than 90 degrees.
8. The thick-walled article of claim 7 wherein the number of said
locker warp yarn planes and said stuffer warp yarn planes
comprising said first and third yarn systems varies along the axis
of said fabric so that as the distance between said thick-walled
article surface and said axis fluctuates a uniform fabric density
is maintained.
9. The thick-walled article of claim 6 wherein said fabric includes
an inner and an outer surface and wherein each of the locker warp
yarns diagonally traverses selected ones of said filling yarn
planes reciprocating between said inner and outer fabric surfaces
within said locker warp yarn planes radially disposed with respect
to said axis.
10. The thick-walled article of claim 9 wherein the number of
locker warp yarns comprising a given plane at least equals the
number of filling yarn picks comprising a filling yarn deck having
been traversed by said locker yarn plane.
11. The thick-walled article of claim 10 wherein the number of
stuffer yarns comprising a given plane is less than the number of
filling yarn picks comprising the filling yarn deck having been
traversed by said given stuffer yarn plane.
12. The thick-walled article of claim 2 wherein said filling yarn
picks are circumambiently positioned about said axis.
13. The thick-walled article of claim 12 wherein said stuffer yarn
planes and said locker yarn planes are radially disposed with
respect to and include said axis and which in combination with said
filling yarn planes form a fabric having irregular cross-sectional
dimensions.
14. The thick-walled article of claim 13 wherein the number of
locker yarn planes and stuffer yarn planes traversing selected
filling yarn planes varies along the axis of said fabric
proportionally with the distance between said selected filling yarn
planes and said axis to maintain a uniform fabric density.
15. The thick-walled article of claim 12 wherein said predetermined
three-dimensional shape is a cylinder.
16. The thick-walled article of claim 12 wherein said predetermined
three-dimensional shape is a truncated cone.
17. The thick-walled article of claim 12 wherein said predetermined
three-dimensional shape is a hyperboloid of revolution of one
sheet.
18. The thick-walled article of claim 12 wherein said predetermined
three-dimensional shape is a truncated paraboloid of
revolution.
19. The thick-walled article of claim 12 wherein said fabric
includes inner and outer surfaces and wherein said locker yarns
comprising said locker yarn planes extend reciprocally from said
inner surface to said outer surface to encompass the outermost
lying and the innermost lying of said filling yarns forming a given
deck whereby the filling yarn deck integrity is maintained.
20. A thick walled substantially rigid fabric comprising a
plurality of integrally combined yarn systems each of which
includes a plurality of yarn planes spatially arranged about a
reference axis, the yarn planes of a first yarn system being
parallel to each other and normal to said axis, the yarn planes of
a second yarn system being radially aligned with respect to said
axis, the yarns of said second yarn planes traversing and
interlocking the yarns of said first yarn planes to maintain the
integrity of said first yarn system and the yarn planes of a third
yarn system being radially aligned with respect to said axis and
traversing said yarn planes of said first yarn system.
21. The shaped fabric of claim 20 wherein the yarn planes of said
third yarn system alternate in sequence with said yarn planes of
said second yarn system.
22. The shaped fabric of claim 21 wherein said fabric is
substantially free of localized stress areas.
23. The shaped fabric of claim 22 wherein said fabric has a uniform
fabric density.
24. The shaped fabric of claim 22 wherein said fabric has a
non-uniform fabric density.
25. The shaped fabric of claim 21 wherein said fabric has a uniform
fabric density.
26. The shaped fabric of claim 21 wherein said fabric has a
non-uniform fabric density.
27. The shaped fabric of claim 23, said fabric defined by inner and
outer surfaces and wherein the yarns comprising said yarn planes of
said second yarn system lie in paths reciprocating between said
fabric inner and outer surfaces.
28. The shaped fabric of claim 24, said fabric defined by inner and
outer surfaces and wherein the yarns comprising said yarn planes of
said second yarn system lie in paths reciprocating between said
fabric inner and outer surfaces.
29. The shaped fabric of claim 27 wherein said yarns of said first
yarn system are circumambiently positioned about said axis.
30. The shaped fabric of claim 28 wherein said yarns of said first
yarn system are circumambiently positioned about said axis.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the formation of an integrally woven,
shaped fabric and more particularly, to a fabric which is woven in
accordance with a predetermined pattern, the pattern providing a
curvilinear design and a fabric thickness so as to provide a
three-dimensionally shaped article having walls comprised of yarn
systems which provide reinforcement against stress in three
mutually perpendicular planes.
2. Description of the Prior Art
With the advent of certain high performance fibers such as carbon,
graphite, quartz, steel, certain organic polymeric fibers including
the polyimides which are resistant to high temperatures and which
exhibit excellent tensile properties when subjected to high
temperatures, a need has arisen for shaped, three-dimensionally
woven fabrics which are produced with a relatively high degree of
accuracy to conform to a predetermined configuration and which have
relatively high strength and good uniformity of density throughout.
Such fabrics are especially advantageous in the fiber reinforced
plastics industry where the shaped articles are impregnated with a
resin which is subsequently cured to form a composite structure.
The resulting composite is light in weight, has excellent strength
per unit weight and is extremely useful in the aircraft industry,
pressure vessels and the like. Such articles may be formed in a
variety of ways including filament winding, the weaving of
multi-layered articles on flat looms with the resulting article
being opened up to assume a particular shape, and the weaving by
means of circular looms. A particular process for filament winding
is disclosed in U. S. Pat. No. 3,260,398 to Levenetz. The Levenetz
patent has fibers oriented in such a manner as to be aligned with
the forces developed about the openings in a structure by having
circumferentially wound filaments and a radial fill. The filaments
forming the radial fill with the particular forces exerted thereon
more efficiently support the developed loads since the filaments
are not actually entwined with the other filaments; however, the
structure becomes very weak to forces applied in the lateral
direction.
A recent development in the filament winding art provides a
three-dimensional fabric which encompasses, in addition to the
basic filament winding concept the addition of reinforcement in the
Z-direction. This is accomplished through the utilization of a jig
or fixture having positioned therein spaced apart metal tubes
aligned in the Z-direction. Filaments are threaded between the
tubes to form alternate plies of aligned reinforcements. When
sufficient cross-plies are laid down to produce the required
thickness, they are compressed and the steel tubes are removed.
Thereafter, bundles of filaments are threaded through the holes
left by the tubes to form the Z-direction reinforcement.
Other shaped fabrics are generally disclosed in U. S. Pat. Nos.
3,102,559, 3,090,406 and 3,234,972 to Koppelman et al. Fabrics of
this type are woven on a flat loom using one or more shuttles and
Jacquard means to raise certain warp yarns above the general plane
of weaving to form additional sheds. The shuttles are then advanced
through the various sheds to form a woven fabric in the
conventional manner. The resulting fabric is then opened out and,
if impregnation is desired, impregnated and placed on a mandrel
while the resin cures. In all fabrics of this type, the selvage
areas, as woven, are weak due to the lack of warp yarns in areas
which are transverse to the direction of the force applied on the
same.
Multi-ply tubular fabric has been made on circular looms; however,
the two plies are not interconnected, but one ply is woven on top
of the other ply to eliminate the expensive and time-consuming step
of pulling a first ply through the second one. An example of such
articles are disclosed by U. S. Pat. No. 1,357,967 to Dupray.
Other art of interest includes the braiding process whereby layers
of helically wound and interlocked yarn are woven in a cylindrical
shape with the interlocks being produced at every intersection of
the yarn. Further, needled fabric felts are available and are
produced by forcing fibers vertically through horizontally arranged
layers of fabric which mechanically link them together. Layered
fabrics may also be produced by causing selected fibers of one
layer to be locked into the piles and loops of another layer.
From a review of the prior art, it is obvious that a definite need
exists for a fabric which includes woven thickness as well as
assuming a three-dimensional curvilinear shape.
SUMMARY OF THE INVENTION
The thick-walled articles of this invention consist of fabrics
comprised of at least three warp and two filling yarns in thickness
and which are woven upon the surface of a mandrel. Depending upon
the end use to which the articles may be employed, the fabric may
be woven to have a substantially uniform fabric density. The thick
walls in general are comprised of a plurality of yarn systems
which, for simplicity, may be called filling yarns, locker warp
yarns and stuffer warp yarns. The filling yarns are substantially
equivalent to the weft yarns in a conventional flat fabric while
the locker warp yarns are equivalent to the warp yarns thereof. The
stuffer warp yarns normally are woven in planes perpendicular to
the general planes in which the filling yarns reside. Each of the
yarn systems includes a plurality of yarn planes each of which is
comprised of one or more strands of yarn. Each of the yarn planes
is distinct and traverses selected yarn planes of the other yarn
systems. For example, in a thick-walled tubular, selvage free
fabric producible by the apparatus of this invention, a particular
weave pattern provides stuffer warp yarns arranged in planes that
extend radially outward from the longitudinal axis of the fabric
and lengthwise thereof. The filling yarn picks to be herein after
described lie in a series of parallel planes which are normal to
the longitudinal axis of the fabric. The locker warp yarns form
planes that sequentially alternate with the stuffer warp yarn
planes and are substantially parallel thereto. Thus, for the
pattern described, the filling yarns traverse both the stuffer and
locker warp yarn planes. In weaving a cylinder of the type
described, the stuffer and locker warp yarns may be combined into a
single yarn system comprised of a plurality of yarn planes which
traverse the filling yarn planes.
Therefore, an object of this invention is to provide thick-walled,
integrally woven, three-dimensionally shaped fabrics.
Another object of this invention is to provide a shaped,
thick-walled fabric which is comprised of a plurality of yarn
systems each of which defines a plurality of yarn planes with the
yarn planes of each yarn system being distinct and traversing
selected yarn planes of the other yarn systems.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective, fragmented view of an integrally woven
truncaled cone;
FIGS. 2 through 26 are section views through a first fabric
embodiment showing in sequence the manner in which two decks of
filling yarns are woven into the fabric;
FIGS. 27 through 35 are section views through a second fabric
embodiment showing portions of the sequence for weaving one deck of
filling yarn into the fabric.
FIRST FABRIC EMBODIMENT
FIGS. 2-26 illustrate the segmented insertion of filling yarn in
the weaving of a given fabric with the utilization of four filling
yarn inserters. The fabric 280 comprises a plurality of locker warp
yarns 281, a plurality of filling yarns 282, and a plurality of
stuffer warp yarns 283.
Each horizontal row of filling yarns 282 will hereinafter be called
a deck while each vertical row of filling yarns will be called a
course which is not to be confused with the definition of a
"course" in knitting. For a given fabric, the number of filling
yarns forming a deck is dependent upon the required fabric
thickness. For example, the embodiment shown in FIGS. 2-26 has 12
filling yarns per deck. The number of filling yarns forming a
course will vary with the length of the fabric. The number of
stuffer warp yarns across a given deck will vary with the thickness
of the fabric and will be one less than the number of filling
yarns, i.e., eleven stuffer yarns are employed in the embodiment
depicted in FIGS. 2-26. For purposes of illustration, the courses
of filling yarns are numbered 284, 285, 286, 287, 288, 289, 290,
291, 292, 293, 294, and 295.
The number of courses which may be woven into a given fabric is
dependent upon the number of filling yarn inserters utilized in the
weaving thereof. That is, the number of courses of which a given
fabric may be comprised must be a whole number multiple of the
number of filling yarn inserters employed in the weaving thereof.
For example, if two filling yarn inserters were to be employed to
weave the fabric of FIGS. 2-26, the first filling yarn inserter
would be programmed to weave courses 284 through 289 and the second
filling yarn inserter would be programmed to weave courses 290-295.
Whenever more than one filling yarn inserter is employed each will
be programmed to weave adjacent courses to prove an ordered yarn
fabric.
In the instant example, the four filling yarn inserters may be
called first, second, third and fourth with the first filling yarn
inserter supplying filling yarn to courses 284, 285, and 286; the
second filling yarn inserter supplying filling yarn to courses 287,
288, and 289; the third filling yarn inserter supplying filling
yarn to courses 290, 291 and 292; and the fourth filling yarn
inserter supplying filling yarn to courses 293, 294, and 295.
In reference to FIG. 2, deck 296 has been completed by the
insertion of filling yarn 297 which is the last of such yarn to be
placed in deck 296 for that particular sequence. It can be seen
that locking warp yarns 298 and stuffer warp yarns 299 and 300 form
the upper portion of the shed while stuffer warp yarns 301, 302,
303, 304, 305, 306, 307, 308, 309 and locking warp yarns 310 form
the bottom portion of the shed. To prepare for the formation of
deck 311, the shed is changed by the Jacquard heads so that stuffer
warp yarns 299 through 309 and locker warp yarn 310 form the upper
portion of the shed while locker warp yarn 298 forms the bottom
portion of the shed. In FIG. 3, filling yarn 312 which is carried
by first filling yarn inserter is carried through the shed formed
as described immediately above and pulls locker warp yarn 298
inwardly until the same rests against the mandrel 81. Since first
filling yarn inserter is immediately followed by second filling
yarn inserter, the shed is changed by the Jacquard head (as shown
in FIG. 4) so that the stuffer warp yarns 299 through 306 and the
locker warp yarn 310 form the upper portion of the shed while
stuffer warp yarns 307, 308 and 309 and locker warp yarns 298 forms
the lower portion of the shed. In FIG. 4, filling yarn 313 is laid
in the course 287 and remains there since stuffer warp yarn 307
prevents filling yarn 313 from being drawn closer to the mandrel 81
and filling yarn 313 is thereafter held in that position by the
tension induced by second filling yarn inserter.
In FIG. 5, the filling yarn 314 is placed in course 290 by third
filling yarn inserter. The upper portion of the shed is formed by
the stuffer warp yarn 299 through 303 and locking warp yarn 310
while the lower portion of the shed is formed by stuffer warp yarn
304 through 309 and locker warp yarn 298. The shed as programmed by
the Jacquard heads and as shown in FIG. 6 has its upper portion
comprised of the stuffer warp yarns 299 and 300 and the locker warp
yarns 310 and the lower portion of the shed is formed by stuffer
warp yarns 301 through 309 and locker warp yarn 298. Filling yarn
315 is placed into course 293 by the fourth filling yarn inserter.
It can now be seen that each of the filling yarn inserters has made
one complete revolution.
In FIG. 7, filling yarn 316 is directed into course 285 by the shed
which has its upper portion formed of stuffer warp yarns 299
through 308 and locker warp yarn 310 and the lower portion formed
of stuffer warp yarns 309 and locker warp yarns 298. Filling yarn
316 is carried by first filling yarn inserter and in effect is a
continuation of filling yarn 312.
In FIG. 8, the upper portion of the shed is comprised of the locker
warp yarns 310 and stuffer warp yarn 299 through 305 and the lower
portion of the shed is comprised of the locker warp yarn 298 and
stuffer warp yarns 306 through 309. Filling yarn 317 is inserted in
course 288 by second filling yarn inserter, filling yarn 317 being
a continuation of filling yarn 313. In FIG. 9, the shed has its
upper portion comprised of the stuffer warp yarns 299 through 302
and the locker warp yarn 310 has the lower portion of the shed
comprised of the stuffer warp yarns 303 through 309 and the locker
warp yarn 298. Filling yarn 318 is laid into course 291 by the
third filling yarn inserter as a continuation of filling yarn 314.
In FIG. 10, the shed has its upper portion formed of locker warp
yarn 310 and stuffer warp yarn 299. Filling yarn 319 is laid into
course 294 by the fourth filling yarn inserter and is a
continuation of filling yarn 315. It can be seen that the filling
yarn inserters have made a second revolution and each has laid its
yarn in the selected course.
The filling yarn deck 311 is completed by a third revolution of
each of the filling yarn inserters; the beginning of which is shown
in FIG. 11, wherein the upper portion of the shed is comprised of
the stuffer warp yarns 299 through 307 and locker warp yarn 310
while the lower portion of its shed is comprised of the stuffer
warp yarns 308 and 309 and locker warp yarn 298, the filling yarn
320 is inserted into course 286 by first filling yarn inserter and
is a continuation of filling yarn 316. In FIG. 12, the shed has the
upper portion thereof formed by stuffer warp yarns 299 through 304
and locker warp yarn 310 and has the lower portion thereof
comprised of the stuffer warp yarns 305 through 309 and the locker
warp yarns 298. Filling yarn 321 is laid into course 289 by means
of the fourth filling yarn inserter with filling yarn 321 a
continuation of filling yarn 317. In FIG. 13, the shed has its
upper portion formed from stuffer warp yarns 299, 300 and 301 and
locker warp yarn 310. The filling yarn 322 is inserted into course
292 by the third filling yarn inserter, filling yarn 322 being a
continuation of filling yarn 318. In FIG. 14, deck 311 is
completed. The shed therein has its upper portion formed by locker
warp yarn 310 and has the lower portion of its shed formed by the
locker warp yarns 298 and stuffer warp yarns 299 through 309.
Filling yarn 323 is inserted into course 295 by means of the fourth
filling yarn inserter.
In FIG. 15, the filling yarn deck 324 is begun by the first filling
yarn inserter inserting the filling yarn 325 into the course 286
with the lower portions of the shed comprising the locker warp
yarns 310 and the stuffer warp yarns 308 and 309. During the
insertion of the filling yarn 325 into course 286 the tip of the
first filling yarn inserter has forced the locker warp yarns 310
toward the mandrel surface. The filling yarn 325 is a continuation
of the filling yarn 320 and is seen to reside in the same course
286.
Since both the filling yarns 320 and 325 are inserted by the same
filling yarn inserter upon successive revolutions thereof it should
be apparent that the first, second, third and fourth filling yarn
inserters are programmed such that the tip thereof are neither
retracted or extended between the completion of the weaving of one
deck of filling yarns and the starting of the next successive deck.
The latter mode of programming the retraction and extension of the
filling yarn tips is utilized regardless of the weave pattern or
the number of filling yarn inserters being employed to maintain an
ordered fabric weave.
It can be seen that locker warp yarns 298 will remain in the upper
shed until the filling yarn deck 324 is completed.
In FIG. 16, the shed is formed substantially like the shed shown in
FIG. 11 with the filling yarn 326 being laid into the course 289 by
means of the second filling yarn inserter. The filling yarn 326
remains in course 289 even though under tension, for stuffer warp
yarns 305 prevent the same from moving toward the mandrel 81. In
FIGS. 17 and 18, the sheds are formed as previously depicted in
FIGS. 12 and 13 with filling yarns 327 and 328 respectively laid
into courses 292 and 295 by means of third filling yarn
inserters.
In FIG. 19, the shed has its upper portion formed by the stuffer
warp yarns 299 through 308 and locker warp yarns 298 and the bottom
portion formed by stuffer warp yarns 309 and the locker yarns 310.
Filling yarn 329 which is a continuation of filling yarn 325 is
passed through the shed and laid in the course 285 by first filling
yarn inserter. Also viewing FIG. 15, it can be seen that the locker
warp yarn 310 has its extremity moved inwardly from course 286 to
285 by means of the tip of the first filling yarn inserter. The
filling yarn 329 is prevented from moving closer to the mandrel 81
and into course 284 by means of the stuffer warp yarns 309. In
FIGS. 20, 21, and 22, the sheds for allowing filling yarn 330, 331
and 332 to be woven into the courses 288, 291 and 294 respectively
by means of the second, third and fourth filling yarn inserters is
much the same as has been described for the formation of the sheds
for those particular courses.
The shed as shown in FIG. 23 has its upper portion comprised of all
of the stuffer yarns and has its lower portion comprised only of
the locking warp yarns 310. Thus, as first filling yarn inserter
proceeds through the shed, the tension thereof draws the locker
warp yarns 310 into a position adjacent the mandrel by placing
filling yarn 333 in course 284. The filling yarn 333 is a
continuation of the filling yarn 329. Thus, it can be seen that
since the first filling yarn inserter only supplies such yarn to
courses 284, 285, 286, all of the filling yarn in those courses are
a continuation of each other. In FIGS. 24, 25 and 26, the filling
yarns 334, 335 and 336 are respectively positioned into courses
287, 290 and 293 by means of second, third and fourth filling yarn
inserters. The sheds are formed in essentially the same way as
herein before set forth for the particular courses in question.
Thus, upon the insertion of filling yarn 336, the complete cycle
which includes filling yarn decks 311 and 324 is completed
whereupon the procedure is repeated until the product is woven.
The FIGS. 2-26 show a fabric having a thickness of twelve filling
yarns, eleven stuffer warp yarns and two locker warp yarns;
however, this thickness may be varied over a space of several decks
or from deck to deck if a contoured external surface of the woven
product were required. This may be accomplished by providing
sufficient additional stuffer warp yarns that are maintained
external of the as woven fabric in the upper portion of the shed
until such time as they are inserted into the weaving shed by the
program of the Jacquard heads. Simultaneously with the insertion of
the additional stuffer warp yarns into the weaving shed by the
plurality of Jacquard heads of the yarn filling inserters would be
programmed to extend and retract over a greater number of courses
in accordance with the number of stuffer warp yarns to be added. As
previously discussed the number of stuffer warp yarns which are to
be added or subtracted from the fabric during the weaving process
must be a whole number multiple of the number of filling yarn
inserters being utilized. In the example at hand the stuffer warp
yarns would have to be added or subtracted in multiples of four
since four filling yarn inserters are being employed to weave the
fabric.
It may be seen that the utilization of a single filling yarn
inserter provides for the greatest flexibility with respect to
increasing or decreasing the fabric thickness during weaving but
has the disadvantage of providing the slowest rate of fabric
production.
SECOND FABRIC EMBODIMENT
In FIGS. 27--35, a different pattern is depicted wherein the locker
warp yarns as previously described are woven in a diagonal
manner.
Filling yarns 352 are arranged in courses 340 through 351 and are
separated both by locker warp yarns 353 and stuffer warp yarns 354.
Depending upon the end use of the fabric, stuffer warp yarns 354
may or may not be incorporated into the fabric. The main purpose of
such stuffer warp yarns 354 is to increase dimensional stability in
the vertical direction. The particular pattern assumed by locker
warp yarns 353 is controlled by the manipulation of the shed by
means of the Jacquard heads, the pattern design being quite
flexible and being limited only by the maintenance of such yarns in
a given plane. For the embodiment shown, four filling yarn
inserters are used with first filling yarn inserter laying in
filling yarn 352 for courses 340, 341 and 342, second filling yarn
inserter laying in filling yarn 352 for courses 343, 344 and 345,
third filling yarn inserter laying in filling yarn 352 for courses
346, 347 and 348 and fourth filling yarn inserter laying in filling
yarn 352 for courses 349, 350 and 351. The sequence for laying in
filling yarns 352 is substantially the same as has been previously
described for the first revolution of the filling yarn inserters,
the four filling yarn inserters respectively lay in filling yarns
355, 356, 357 and 358 in courses 340, 343, 346, and 349. In order
to preserve the diagonal pattern as set forth, locker warp yarn 359
immediately prior to and during the insertion of filling yarn 360
into course 341 by first filling yarn inserter is held in the lower
part of the shed and therefore extends between filling yarn 360 and
filling yarn 355. The second revolution of filling yarn inserters
respectively inserts filling yarns 360, 362, 363 and 364 into
courses 341, 344, 347 and 350. Deck 365 is completed upon the
completion of the third revolution of each of the filling yarn
inserters wherein filling yarns 352 are woven sequentially into
courses 342, 345, 348 and 351. The immediately following deck is
then sequentially woven into the fabric courses in the following
order: 342, 345, 348, 351; 341, 344, 347, 350; 340, 343, 346 and
349. Upon the completion of the insertion of the filling yarn 352
into into course 349, the sequence is ready to be repeated starting
again with the weaving of the filling yarn 352 into course 340.
It can be seen that by eliminating the stuffer warp yarn 354, a
thick-walled intricately woven three dimensionally shaped fabric
may be woven with only two yarn systems, those being filling yarns
352 and locker warp yarns 353.
* * * * *