US3362436A

US3362436A - Method and apparatus for the production of a fabric free of warp-wise running irregularities at a wave weaving loom

Info

Publication number: US3362436A
Application number: US481471A
Authority: US
Inventors: Fend Heinrich
Original assignee: Oerlikon Buehrle Holding AG
Current assignee: OC Oerlikon Corp AG Pfaeffikon
Priority date: 1964-10-09
Filing date: 1965-08-23
Publication date: 1968-01-09
Anticipated expiration: 1985-01-09
Also published as: NL6512229A; GB1128032A; DE1291295B; BE670643A; CH421014A; AT265163B; ES318610A1

Description

Jan. 9, 1968 H. FEND 3,362, METHOD AND APPARATUS FOR THE PRODUCTION OF A FABRIC FREE OF WARP-WISE RUNNING IRREGUIJARITIES AT A WAVE WEAVING LOOM Filed Aug. 23, 1965 2 Sheets-Sheet 1 H. FEND 3,362,436 FOR THE PRODUCTION OF A FABRIC Jan. 9, 1968 METHOD AND APPARATUS 2 Sheets-Sheet 2 Filed Aug. 23, 1965 INVENTOR HEINRICH FEND i B ATTORNEYS United States Patent 3,362 436 METHOD AND APPARATUS FOR THE PRODUC- TION OF A FABRIC FREE OF WARP-WISE RUNNING IRREGULARITIES AT A WAVE WEAV- ING LOOM Heinrich Feud, Uster, Zurich, Switzerland, assignor to Oerlikon-Buhrle Holding A.G., Zurich, Switzerland Filed Aug. 23, 1965, Ser. No. 481,471 Claims priority, application Switzerland, Oct. 9, 1964, 13,145/ 64 15 Claims. (Cl. 139-12) ABSTRACT OF THE DISCLOSURE The movement of the fell line in wave weaving looms is controlled so as to produce a fabric with the warp-wise running irregularities removed. This is accomplished by providing a stationary segment shaped deflecting member cooperating with the cloth formed at the fell line and extending forwardly of the fell line. Such deflecting member has a convex guiding surface extending in the direction of the warp. Cooperating therewith are stationary adjustable convex guiding members. Also in order to reduce the weight of the guiding members such members in unloaded state may be bent so that when loaded the curvature will be partially reduced.

The present invention has reference to an improved method of, and apparatus for, the production of fabrics free of warp-wise running irregularities in a wave weaving loom.

During weaving upon conventional looms beating of each weft thread at the fell of the cloth takes place, after insertion of such weft thread simultaneously across the entire fabric width, by means of a reed extending across such fabric width. Due to such beating the fell line of the cloth is temporarily displaced forwards, the tension of the still unwoven portion of the chain of warp threads forming the shed temporarily increasing across the full weaving width, and the tension of the fabric extending from the fell line to the cloth beam temporarily reducing, also across the entire cloth width. At this moment the fabric is advanced forwardly through a weft thread spacing. Upon return of the reed the tension of the unwoven warp portions and the fabric again balances, whereby the fell line formed by the newly beaten Weft thread returns to its former position.

In order to prevent the tension at the still unwoven warp portions from becoming too great at the moment of beating and in order to reduce the danger of rupture of the warp threads, it has already been proposed that the fell line of the departing fabric be permitted to pass over both edges of a trough having a cross-section which widens in trapezoidal manner towards the bottom, and for the fabric to pass between these edges beneath a rod disposed in this trough, the diameter of which is larger than the mutual spacing of the aforementioned edges of the trough.

Owing to the increased tension of the fabric during return of the reed, this rod is pulled towards the. walls of the trough which narrows towards the top and is wedged therebetween, whereby the fabric is fixedly clamped so that it cannot move backwards any furthenThe unwoven warp portions, the tension of which again assumes a value controlled by a regulating device, t-hus experience a small elongation during the next beating action of the reed and attain a smaller maximum tension than with free movement of the fell line of the cloth.

In wave weaving looms-that is, looms in which weft threads are inserted and beaten in a plurality of wave-like sheds of finite or limited width successively following one another across the weaving widthbeating of each weft 3,352,436 Patented Jan. 9, 1968 thread at the fell line of the fabric takes place, in each instance, directly after the insertion of a small section of such weft thread at a corresponding section of the cloth width, by means of one of a plurality of juxtapositroned reed groups moving forwardly and rearwardly in time-displaced cycles. Formation and changing of the sheds likewise occurs by means of a plurality of juxtapositioned harness groups working in displaced operating cycles. As a result, differences in the tension of the warp threads can appear from one harness group to the other and from one reed group to the other, which during beating results in different displacements of the fell line with free displaceability of the fabric. Thus, in the finished fabric there appear stripes of differently woven goods which extend in the direction of the warp, the width of which substantially corresponds to that of the harness groups and reed groups. Such striped cloth is not desirable and, therefore, it is a primary objective of the present invention to prevent such.

Another more specific object of this invention is to provide an improved method of, and apparatus for, weaving a fabric at a wave weaving loom which is substantially free of warp-wise running irregularities.

The previously mentioned known measure of permitt ng the fabric to pass beneath a clamping rod or bar located in a trough possessing a cross-section which narrows towards the top is not applicable for wave weaving looms since such a clamping rod extends across the full cloth width and can only then function satisfactorily if each weft thread is simultaneously beaten along the entire length of the rod. However, it must be remembered when weaving upon a wave weaving loom that each short, newly inserted, section of each weft thread which is in the process of being inserted, is beaten by a reed group of small width almost simultaneously with its insertion.

Thus, in order to solve the aforementioned problem with which the invention is concerned, it must be possible for the fabric to be advanced forwards in the region of th s small width, and in the remaining portion of the weaving width it must be fixed against displacement in the warp direction. According to the invention this is achieved by causing the fabric which runs forward from the said fell, to pass in the region immediately adjacent to the fell over at least one stationary surface having a convex curvature in the warp direction of the fabric, whereby the fabric is maintained in frictional engagement with said surface as a result of the warp-wise tension in which it is subjected. Accordingly, those portions of the fell of the fabric on which tension is exerted through the still unwoven portions of the warp threads running towards the fell on one side, and through the adjacent forwardly extending portion of the fabric on the other side, are immobilized by the said frictional engagement against Warp- Wise displacement. However, such displacement is rendered possible by reduction or temporary suppression or suspension of such frictional engagement for those portions of the fell at which a weft thread is being beaten up by members (hereinafter called reed groups) which at least temporarily prevent the tension of the said unwoven warp thread portions from being transmitted to the fabric which extends forwardly of the fell.

Other features, objects and advantages of the invention will become apparent by reference to the following detailed description and drawings in which:

FIGURE 1 is a schematic longitudinal sectional view through a wave Weaving loom equipped with a preferred embodiment of the apparatus;

FIGURE 2 is a fragmentary schematic top plan view of a portion of the wave weaving loom of FIGURE 1 equipped with the inventive apparatus for performing the inventive method; and

FIGURE 3 is a partial perspective view showing the cloth deflecting members.

Turning attention now to the drawings, it will be understood that the illustrated wave weaving loom possesses a warp beam 11 from which travels a chain of warp threads which pass over a tension beam 12 and partially through harnesses 13, partially through harnesses 14, which deflect the warp threads 10 upwardly and downwardly in order to form sheds 29. The chain of warp threads 10 pass from the

harnesses

13, 14 towards the fell line 15. As best recognized by inspecting FIGURE 2, the

individual harnesses

13, 13, 13", 13", etc. and 14, 14', 14", 14", etc., in each instance, only extend over a small portion of the weaving width. They are displaced differently upwards and downwards in sucha manner that each shed only extends over a few, approximately 3, harness widths and travels in the direction of the arrow 31, from the left to the right, across the weaving width. In each such travelling shed a weft thread is inserted by a shuttle 28 and behind such shuttle the inserted thread is beaten towards the fell line 15 by means of a group of reeds 27 which extend across a fraction of the harness width. This fell line 15 is formed at each location of the fabric width by a weft thread inserted in the last shed travelling through this location which is beaten and interlaced by the warp threads crossing over this weft thread at the rear of this shed with respect to the weft inserting direction.

The fabric continuously produced at such fell line 15 moves over a stationary support surface or rail 16 extending transversely over the full fabric or cloth width. Support or deflecting rail 16 has a deflecting surface 15a which substantially possesses the form of a segment of a cylinder and exhibits grooves or ridges 32 extending obliquely towards the outside from the rear towards the front (FIGURE 2). In the illustrated embodiment, the fabric 20 is then guided beneath a likewise stationary cylindrical rod 17 extending over the same cloth width and then is guided over a similar stationary rod 18. From the latter the fabric moves further over an indexing or controller roll 21 which rotates continuously during operation of the loom, then between such indexing roll 21 and a cooperating contact roll 22, and over the latter to the cloth beam 23 where it is wound up. Cloth beam 23 is driven with a controlled rotational speed in such a manner that a cloth package is formed thereon, the cloth possessing a uniform tension.

The deflecting or support rail 16 is stationarily seated upon a box or housing 24 mounted on the frame 30 of the loom. This box 24 contains the drive mechanism for the reed group 27 and the shuttles 28. Box 24 also supports both of the deflecting rollers or

rods

17 and 18 through the agency of lateral support plates 19 connected to the aforesaid box.

Rods

17 and 18 engage by means of rectangular shaped end studs or

lugs

17a and 18a respectively, with appropriate recesses 19a and 1% respectively provided at the plates 19, and specifically, in such a manner that they cannot rotate about their corresponding lengthwise axis, yet are easily demountable.

Slides 25 capable of moving to and fro between a forward and rear terminal position are guided in the box 24 and extend rearwardly beneath the region in front of the

harnesses

13 and 14 traversed by the travelling sheds 29. At its rear end each slide member 25 carries one of the reed groups 27, the individual beat-up reeds of which, during each position of the slide, piercingly extend upwards between the warp threads 10 and during movement of the slide 25 move to and fro between a rear terminal position neighboring the

harnesses

13 and 14 and a forward terminal position directly neighboring the support rail 16 and determining the position of the fell line 15. A bifurcated 0r forked member 26 is seated upon each slide 25 in front of the reed group 27 and which together with the slide 25 neighboring the corresponding bifurcated member 26 receives a rib-shaped, bent, lower projection of the momentarily passing shuttle 31, whereby this shuttle in known manner, and for such reason not explained more fully, is forwardly driven due to the relative movement of the neighboring slides 25. In my co-pending U.S. applications, Ser. No. 294,971 and Ser. No. 294,980, both filed July 15, 1963, there is disclosed mechanism for driving the shuttles across the weaving width at a wave weaving loom, and reference may be readily had thereto. However, since details of the physical structure of such mechanism are not believed necessary for understanding the teachings of the present invention no further description thereof is here given.

During operation of the loom the indexing roll or beam 21 is driven at a speed proportional to the travelling speed of the shuttles 28 and reciprocal to the desired weft thread density. This indexing roll 21 strives to withdraw the warp chain 10 from the warp beam 11 via the fabric 20. This warp beam 11 is uniformly braked in known manner and, thus, maintains the tension of the unwoven portion of the warp chain 10 constant. The fabric 20 extending forwardly from the fell line 15 is guided with such a deflection over the support rail 16 and the

rods

17 and 18 disposed directly in front of the fell line 15, that it is pulled with a certain pressure against the corresponding surfaces of such

deflecting elements

16, 17 and 18, on the one hand, by the tension of the u'nwoven portion of the warp threads 10 and, on the other hand, by the tension in'iparted to it by the indexing roll 21. Due to the friction of the fabric 20 at such surfaces and caused by such pressure the fabric is fixedly held against displacement in the direction of the warp, so that the tension of the indexing roll 21 upon the fabric 20, without anything further, will not bring about any displacement in the warp direction. In fact, an equilibrium or balance condition appears at each partial region of the fabric width, between the tension of the fabric generated by the indexing roll 21 the friction at the

deflecting elements

16, 17 and 18, and the sum of the tensions of the unwoven portion of the warp thread 10 controlled by braking of the warp beam 11. This equilibrium condition remains as long as there i maintained the mentioned tension of the warp thread chain 10 on the one hand, and the tension of the fabric 20 on the other hand.

Now, if a group of reeds 27 beats the weft thread, which occurs in succession in each instance at those locations of the fell line 15 at which a corresponding section of weft thread has been inserted by a travelling shuttle 28, then this group of reeds 27 exerts a forwardly directed force upon the fabric disposed in its region. As a result, the tension of the fabric at the fell line 15, in other words between the beating reed group 27 and the support rail 16, in this region of the fabric width is temporarily reduced beneath the tension of the corresponding unwoven war-p thread section 10 extending from the warp beam 11 to the fell line 15. At the same time, there is also reduced the tension of the fabric in this width range travelling over the

deflecting rollers

16, 17 and 18 and also the frictional force effective between such members and the fabric. This results in the fact that after a certain displacement of the fell line 15 of the fabric by the reed group 27 the tension imparted by the indexing or controller roll 21 to the fabric 20 is suflicient to forwardly displace the fabric to such an extent in the region determined by the width of the beating reed group 27 as the reed group after impacting against the weft thread to be beaten still moves further.

Since this weft thread is displaced by the reed group 27 to the same location previously occupied by the last weft thread beaten by it, and since further movement of the fabric 20 at the side of the indexing roll 21 is prevented by the

defiecting members

16, 17 and 18, the newly inserted weft thread is only displaced forwardly through a weft thread division of the fabric 20.

This feed is not hindered on account of its minuteness by the fact that at both neighboring regions of the fabric width, at which other reed groups are effective, at the same moment there does not appear any feed of the fabric 20. This difference in feed is momentarily compensated due to the mutual displaceability of the threads also in the finished fabric and due to its elasticity; moreover, it only occurs at the forward flank of the relevant reed group 27 with respect to the direction of travel of the shuttles 28, since the reed groups in this direction of travel successively perform a beating action and each thus forwardly displaces the Weft thread to the same extent as it has been forwardly displaced in the previous moment by the reed group located at its rear flank.

The elasticity of the fabric 20 also makes it possible to continuously rotate the indexing or controller roll 21 notwithstanding the fact that the feed movement of the fabric 20 is intermittent a each location of its width.

When each reed group 27 moves back again, the weft thread section which has been displaced forwardly by that reed group and which now forms part of the fell line 15 at that place, remains at the location up to which it has been displaced. This is so because at the same time as the tension prevailing in the still unwoven portions of the respective warp threads again becomes effective on the fell of the fabric rather than on the receding reed group 27, the tension placed upon the fabric by the rotation of the indexing beam 21 again assumes its former value due to the braking effect exerted on the warp beam 11. Since this tension prevails in the fabric 20 both at the fell 15 thereof and at each of the deflecting

members

16, 17 and 18, the friction caused by the engagement of the fabric with the surfaces of these members becomes so high that the tension placed upon the fabric 20 by the indexing beam 21 no longer is large enough to advance the fabric in the region of its fell 15.

The outcome of this is that a certain average tension appears at the fabric 20 between the group of deflecting

members

16, 17 and 18 and the indexing roll 21 which is dependent upon, the tension of the still unwoven warp thread section 10 maintained by braking the warp beam 11, the frictional conditions prevailing at the mentioned deflecting members, and the angular velocity of the indexing roll 21. This tension of the fabric 21} can be greater or smaller than the corresponding tension of the warp thread section 10. It determines at which moment during heating by a reed group 27 displacement of the fabric in the degion of the fell line 15 begins and through which path this fabric thus passes until the reed group 27 has reached its forward terminal position, that is, how large will be the weft thread distribution of the fabric. With a given tension of the unwoven warp thread section 10, given friction at the deflecting

members

16, 17 and 18, and for instance with large feed of the fabric by the indexing roll 21, the tension of the fabric 26 is high since, then, the fabric is more pro-stressed from one "beat to the next of each reed group 27. Upon beating the weft thread a smaller unloading of the fabric at the fell line 15 is then necessary until the friction at the deflecting members is overcome by the fabric tension appearing between such and the indexing beam 21, and the feed movement begins by means of the respective reed group. The feed path. in other words, the weft thread distribution is then larger, with the result that it comes into coincidence with the larger peripheral speed of the indexing roll 21.

In order to be able to change the degree of deflection or deviation of the fabric 20 at the deflecting or

support members

16, 17 and 18 and, thus, to change the friction between the fabric and such deflecting members, it is possible to exchange each of both deflecting

rods

17 and 18 for one of a different diameter. It is also remarked that the possibility exists of completely removing the defleeting rod 18 in order to reduce the Wrap around angle of the fabric at the rod 17.

In order that the diameter of the

rods

17 and 18 can be maintained small, these rods are preferably manufactured so as to have a slight longitudinal curvature in the absence of external forces as shown in FIGURE 3, in such manner that when they will be subjected to the action of the expected tension of the fabric, their axes will be deflected to extend approximately straight from one side plate 19 to the other. As shown in FIGURE 3,

\ in its undeflected state the rod 17 is curved substantially downwards while rod 18- is curved both slightly to the rear and in a larger measure upwards since, as can best be seen in FIGURE 1, the fabric 20 passes under the rod 17 and over the rear upper side of the rod 18. When tension is exerted on the fabric 20 by the indexing roll 21, the fabric exerts an upward force on the rod 17 and a downward and forward force on the rod 18, whereby the rods are deflected until their axes are substantially straight. In this manner it is possible to obtain a precise operation of the apparatus with large weaving Widths, without requiring quite heavy rod profiles or sections.

The

rods

17 and 18 are provided at their ends with

flat extensions

17a, 18a, respectively, which engage

corresponding guide slots

19a, 19b, in the side plates 19. The

guide slots 19a which receive the extensions 17a of rod 17 are horizontal while those 1% which receive the extensions 18a of rod 18 are vertical. Accordingly, the rod 17 is displaceable horizontally and the rod 18 is displaceable vertically each in the corresponding slots; the

flat extensions

17a, 18a prevent the rods 7 and 18 from rotating in their slots. The position of each

rod extension

17a, 18a in the

respective slot

19a, 19b is determined by an adjustment screw 40 screwed through an abutment 190 formed on the side plate 19. By displacing the

rod extensions

17a, 18a in their slots, the positions of the rods 17 can be altered so as to vary the angles at which the fabric 20 runs off the deflecting rail 16 and onto and off the

rods

17 and 18. This permits modifying the friction effect as desired.

The fluting or notching 32 0f the support rail 16 extending obliquely or at an inclination from the inside to the outside in the direction of travel of the fabric 29 causes a traction or tension to be exerted in transverse direction i.e. across the width, upon the fabric directly at the fell line 15, so that such tends to pull together as little as possible after insertion and beating of the weft thread. A corresponding fluting could also be provided at the lower portion of the deflecting roller 17, and, if desired, at the rear and upper sides of the deflecting roller 18, although it is hardly there necessary.

The deflecting or sup-port rail 16 provides the further advantage with regard to shed formation that due to it the elevational position of the fell line 15 is fixed.

It would also be possible to mount this support rail 16, or a deflecting rod provided in place of such, in a manner that the fabric, beginning from the fell line, moves beneath it and then over the next deflecting element or rod 17. The exemplary arrangement shown in the drawing has the advantage that the fell line 15 is readiiy accessible and visible.

, The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art.

I claim:

1. A method of operating a wave weaving loom having a braked warp beam and a tension bar to apply tension to the warp threads, harnesses to form sheds to progressively define a fell line and an indexing roll to apply tension to the progressively formed fabric wherein the movement of the fell line is controlled to form a fabric free of warp-Wise running irregularities, comprising guiding the fabric formed at the fell line and extending forwardly at the region neighboring such fell line over at least one stationary convex guiding surface in the direction of travel of the warp threads and fabric, subjecting each portion of the fabric bearing upon such surface to frictional engagement therewith depending on the tension transmitted to said portion of the fabric by the still unwoven portions of said warp threads extending into said portion opposing the feed of the fabric by said indexing roll, said frictional engagement preventing warp-wise displacement of said portion, and successively beating respective finite regions of the fell line to reduce said force opposing the feed of the fabric forwardly of said fell line to reduce the action of said frictional engagement at each of said respective finite regions to enable forward feed of the latter.

2. Method according to claim 1 including the step of exerting a transverse extending pulling force on the fabric extending forwardly of the fell line in the region of said stationary convex surface.

3. Method according to claim 1 including the step of additionally deflecting the fabric extending forwardly of the fell line over a second convex guiding surface.

4. Method according to claim 3 wherein the fabric extending forwardly of the fell line is deflected over both of said convex guiding surfaces curved in opposite directions.

5. Method according to claim 3 wherein said stationary convex surface closest to the fell line is convex in a substantially upward direction and said second surface follows said first mentioned surface in the direction of travel of the warp and fabric and is convex in a substantially downward direction.

6. A method of operating a wave weaving loom having a braked warp beam and a tension bar to apply tension to the warp threads, harnesses to form sheds to progressively define a fell line and an indexing roll to apply tension to the progressively formed fabric wherein the movement of the fell line is controlled to form a fabric free of warp-wise running irregularities, comprising guiding the fabric formed at the fell line and extending forwardly at the region neighboring such fell line over at least one stationary convex guiding surface in the direction of travel of the Warp threads and fabric, subjecting each portion of the fabric bearing upon such surface to frictional engagement therewith depending on the tension transmitted to said portion of the fabric by the still unwoven portions of said warp threads extending into said portion opposing the feed of the fabric by said indexing roll, said frictional engagement preventing warp-wise displacement of said portion, introducing a weft thread at the region of the fell line, and successively beating respective finite regions of the fell line to reduce said force opposing the feed of the fabric forwardly of said fell line to reduce the action of said frictional engagement at each of said respective finite regions to enable forward feed of the latter.

7. In combination with a wave weaving loom for weaving a woven fabric having a braked warp beam and a tension bar to apply tension to the war-p threads, harnesses to form sheds to progressively define a fell line and an indexing roll to apply tension to the progressively formed fabric, an apparatus to control the movement of the fell line to form said fabric free of warp-wise extending irregnlarities comprising at least one stationary segment shaped deflecting member positioned to cooperate with the woven fabric formed at the fell line and extending forwardly of the fell line, said deflecting member including a sup-port convex guiding surface extending in the direction of the warp of said fabric.

8. The combination set forth in claim 7 wherein said deflecting member is constructed in the form of a rail which extends substantially across the full fabric width.

9. The combination set forth in claim 7 including at least one additional adjustable deflecting member arranged forwardly of said stationary deflecting member in the direction of the warp and fabric travel, both of said deflecting members being arranged in substantial parallelism with respect to one another, said additional deflecting member incorporating a support convex guiding surface cooperating with the fabric passing thereover, said support surfaces of both deflecting members extending in opposite directions.

10. The combination set forth in claim 7 wherein said support surface faces upwardly and possesses an inclination which increases downwardly in the direction of travel of the woven fabric to downwardly deflect the fabric passing from the fell line over said stationary deflecting member.

11. The combination defined in claim 10 including an additional adjustable deflecting member arranged in the direction of travel of the fabric forwardly of and substantially parallel to said stationary deflecting member, said additional deflecting member possessing a support convex guiding surface extending substantially downwardly to upwardly deflect the fabric travelling over said last mentioned support surface coming from said stationary deflecting member.

12. The combination set forth in claim 7 wherein said support surface of said stationary deflecting member is provided with fluting extending at an inclination from the inside towards the outside in the direction of travel of the woven fabric.

13. The combination as set forth in claim 7 including at least a second detachable and exchangeab-ly mounted deflecting member.

14. The combination as set forth in claim 7 including at least a second deflecting member having a support convex guiding surface, and means for adjustably mounting said second deflecting member substantially transversely with respect to its support surface.

15. The combination as set forth in claim 7 wherein said support surface of said stationary deflecting member in the unloaded condition possesses a convex lengthwise profile so that upon loading of said stationary deflecting member by the warp tension of the woven fabric it is bent so that the curvature of said convex lengthwise profile is at least partially reduced.

References Cited OTHER REFERENCES German application 1,072,569, Haberhauer,

pub. December 31, 1959.

HENRY S. JAUDON, Primary Examiner.