EP2894244A1

EP2894244A1 - Method for weaving pile fabrics and pile fabric with shadow cut pile zones

Info

Publication number: EP2894244A1
Application number: EP14150640.2A
Authority: EP
Inventors: Bert Pols; Karsten Siebert
Original assignee: STAUBLI BAYREUTH GmbH
Current assignee: STAUBLI BAYREUTH GmbH
Priority date: 2014-01-09
Filing date: 2014-01-09
Publication date: 2015-07-15
Anticipated expiration: 2034-01-09
Also published as: CN104775223A; EP2894244B1; CN104775223B

Abstract

In this method for simultaneously weaving two pile fabrics (C1, C2) with shadow cut pile zones on a face-to-face weaving machine, an upper backing fabric (F1) and a lower backing fabric (F2) are woven one above the other with at least one filling warp yarns (f1, f2), at least one binding warp yarn (b1, b2), weft yarns (Wi, Wb) inserted in successive weft insertion cycles (P1-P32) between binding warp yarns and filling warp yarns, the weft yarns comprising inner weft yarns (Wi) inserted on a pile side of the filling warp yarns and back weft yarns (Wb) inserted on a back side of the filling warp yarns, opposite to the piles of the fabric. Patterning pile yarns (V) are interlaced in the upper backing fabric (F1) and in the lower backing fabric (F2), each patterning pile yarn turning externally around an inner and a back weft yarns (Wi, Wb) in each backing fabric. At least one patterning pile yarn (V) follows a path where, in a first series of weft insertion cycles (P1-P16) and at least in a first backing fabric (F1, F2), the patterning pile yarn (V) turns externally around an inner weft yarn (Wi) before it turns externally around a consecutive back weft yarn (Wb) and, in a second series of weft insertion cycles (P20-P32) and at least in the first backing fabric, the patterning pile yarn (V) turns externally around a back weft yarn (Wb) before it turns externally around a consecutive inner weft yarn (Wi).

Description

TECHNICAL FIELD OF THE INVENTION

This invention relates to a method for simultaneously weaving two pile fabrics with shadow cut pile zones on a face-to-face weaving machine. This invention also relates to a pile fabric with shadow cut pile zones, which can be woven with such a method.

BACKGROUND OF THE INVENTION

In the field of carpet weaving on face-to-face looms, it is known, e.g. from DE-C-319 324 to obtain two different orientations of the pile legs, thanks to a variation of the structure of the backing fabrics of two carpets. Weft yarns are bound in the backing fabrics on two different levels thanks to tension warp yarns which are also called filling warp yarns or tight warp yarns. Weft yarns include inner weft yarns inserted on the pile side of the tension warp yarns and back weft yarns inserted on the opposite side of the tension warp yarns. Each weft yarn is inserted in an opening defined between a binding warp yarn and at least one tension warp yarn. The patterning pile yarns follow a W-path in the backing fabrics and the pile legs can be brought to a slanted configuration by a modification of the tension warp yarn weave.
WO-A-2013/041938 discloses a method where the orientation of the pile legs of a pile fabric can be changed by changing the weave pattern of the backing fabrics of two simultaneously woven pile fabrics. In practice, binding warp yarns and tension warp yarns which belong to the backing fabrics are fed from beams and shed with heddle frames actuated by a dobby. Thus, a change in the backing fabric weave applies on the total width of the fabric.
With the methods of the prior art, the pile legs orientation can only be changed on the whole width of a fabric, by varying the backing fabric weave structure, which creates strips of differently oriented piles, but no freely designed shadow effect zone.

SUMMARY OF THE INVENTION

This invention aims at solving this problem with a new method for simultaneously weaving two pile fabrics including shadow cut pile zones adjustable both in the warp direction and in the weft direction of the fabric.
To this end, the invention relates to a method for simultaneously weaving two pile fabrics with shadow cut pile zones on a face-to-face weaving machine wherein an upper backing fabric and a lower backing fabric are woven one above the other with at least one filling warp yarn, at least one binding warp yarn and weft yarns inserted in successive weft insertion cycles between the binding warp yarn and the filling warp yarn, the weft yarns comprising inner weft yarns which are inserted on a pile side of the filling warp yarn and back weft yarns which are inserted on a back side of the filling warp yarn, opposite to the piles of the fabric. In this method, patterning pile yarns are interlaced in the upper backing fabric and in the lower backing fabric, each patterning pile yarn turning externally around an inner and a back weft yarns in each backing fabric. According to the invention, at least one patterning pile yarn follows a path where:

in a first series of weft insertion cycles and at least in a first backing fabric, the patterning pile yarn turns externally around an inner weft yarn before it turns externally around a consecutive back weft yarn and
in a second series of weft insertion cycles and at least in the first backing fabric, the patterning pile yarn turns externally around a back weft yarn before it turns externally around a consecutive inner weft yarn.

A first and a second weft yarns are consecutive in a backing fabric when, in a warp direction, these first and second weft yarns extend next to each other, with no other weft yarn located between these two weft yarns. With respect to a backing fabric, a consecutive second weft yarn is a weft yarn which is next, in the warp direction, with respect to a first or reference weft yarn.
Owing to the invention, the slanting direction of one pile yarn can be changed when passing from the first series of weft insertion cycles to the second series of weft insertion cycles. As a patterning pile yarn can be individually driven in its shedding motion via a harness cord actuated by a Jacquard mechanism, the patterning pile yarns can have different shedding positions along the width of the fabric, that is along the weft direction. Moreover, the pick when one patterning pile yarn switches from the first series of weft insertion cycles to the second series of weft insertion cycles can be chosen for each patterning pile yarn, which allows to adapt the place where the slanting orientation of the pile legs change, along the warp direction of the fabrics. In other words, the invention allows to obtain a variation of the slanting orientation of the pile legs in the weft direction and in the warp direction of the fabrics.
In the meaning of the present description, the expression « turns externally» means that a pile yarn "turns" or "winds" or "burls" around a weft yarn, which belongs to a backing fabric, on a side of this weft yarn which is oriented opposite to the backing fabric of the other pile fabric simultaneously woven with the one to which the weft yarn belongs.
According to advantageous but optional aspects of the invention, such a weaving method may incorporate one or several of the following features, considered in any technically allowable combination:

In the first series of weft insertion cycles, the patterning pile yarn turns at least twice externally around an inner weft yarn, then externally around a back weft yarn and, in the second series of weft insertion cycles, the patterning pile yarn turns at least twice externally around a back weft yarn, then externally around an inner weft yarn.
Weft yarn groups, made of at least one inner weft yarn and of one back weft yarn, are inserted in at least one backing fabric, in successive weft insertion cycles, a single binding warp yarn is used to bind all weft yarns to the filling warp yarns in one backing fabric and all weft yarns of a weft yarn group are inserted in openings successively defined by the binding warp yarn and the filling warp yarn.
Weft yarn groups, made of at least one inner weft yarn and of one back weft yarn, are inserted in at least one backing fabric, in successive weft insertion cycles, two binding warp yarns are used to bind all weft yarns to the filling warp yarns of one backing fabric and all weft yarns of a weft yarn group are inserted in a single opening defined by the two binding warp yarns.
In a weft yarn group, a first inner weft yarn, a back weft yarn and a second inner weft yarn are successively inserted in the backing fabric.
Each weft yarn group includes a single type of inner weft yarns which are inserted between the filling warp yarn and a binding warp yarn.
In at least the first backing fabric, at least a dead pile yarn is incorporated in the backing fabric and each weft yarn group includes two types of inner weft yarns, namely an intermediate inner weft yarn, which is inserted between the filling warp yarn and the dead pile yarn, and an innermost weft yarn, which is inserted between the dead pile yarn and the binding warp yarn.
In the first and second series of weft insertion cycles, the patterning pile yarn externally turns around an intermediate inner weft yarn and around a back weft yarn.
Alternatively, in the first and second series of weft insertion cycles, the patterning pile yarn turns around an innermost weft yarn and around a back weft yarn.
The patterning pile yarn follows a path where in the first series of weft insertion cycles and in both backing fabrics, the patterning pile yarn turns externally around an inner weft yarn before it turns externally around a back weft yarn, and in the second series of weft insertion cycles and in both backing fabrics, the patterning pile yarn turns externally around a back weft yarn before it turns externally around an inner weft yarn.
The patterning pile yarn follows a path which has different first and second series of weft insertion cycles in the upper and lower backing fabrics.
For some weft insertion cycles, the patterning pile yarn follows a path where it turns around a back weft yarn and passes between two inner weft yarns.
The backing fabric weave structure, which is defined as the sequence of the consecutive positions of the binding warp yarn and the filling warp yarn in the shed, repeats and remains the same in the first and second series of weft insertion cycles.

This invention also relates to a pile fabric with shadow cut pile zones, this fabric including a backing fabric woven with yarn sets including at least one filling warp yarn, at least one binding warp yarn and weft yarns located between the binding warp yarn and the filling warp yarn, the weft yarns comprising inner weft yarns which are located on a pile side of the filling warp yarn and back weft yarns which are located on a back side of the filling warp yarn, opposite to the piles of the fabric. This fabric also includes pile tufts corresponding each to a patterning pile yarn which belong to a yarn set, which are interlaced in the backing fabric and which each forms two pile legs. According to the invention, for at least one yarn set, at least a first pile tuft and a second pile tuft, which are consecutive in a warp direction of the fabric, are interlaced in the backing fabric in a configuration where:

in the warp direction, the first pile tuft turns externally around an inner weft yarn before it turns externally around a consecutive back weft yarn and
in the warp direction, the second pile tuft turns externally around a back weft yarn before it turns externally around a consecutive inner weft yarn.

According to an advantageous but optional aspect of the invention, this pile fabric includes, on the one hand, weft yarn groups, made of at least one inner weft yarn and of one back weft yarn and, on the other hand, two binding warp yarns used to bind the weft yarns to the filling warp yarn and the patterning pile yarn of a yarn set, whereas all the weft yarns of a weft yarn group go through an opening formed by the two binding warp yarns.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and other advantages thereof will appear more clearly upon reading the following description of several embodiments of a weaving method and a fabric according to its principle, provided solely as an example and made in reference to the appended drawings, in which:

figure 1 is a schematic cross section along the warp direction of two pile fabrics which are woven on a face-to-face weaving machine, this cross-section representing a first weaving method according to the invention,
figure 2 is a front view of a carpet woven with the method represented on figure 1, this carpet being also according to the invention,
figures 3 to 8 are schematic views similar to figure 1 for a second, a third, a fourth, a fifth, a sixth and a seventh method according to the invention.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

Figure 1 is a schematic cross-section, in the warp direction, of two carpets C1 and C2 simultaneously woven one above the other on a face-to-face weaving machine or loom, with two non represented insertion means.
Picks P1 to P32 are represented on figure 1 and define insertion cycles for weft yarns.
Each carpet C1 or C2 includes a backing fabric F1, respectively F2, and piles D1, respectively D2, extending from one backing fabric F1 or F2 towards the other backing fabric. Backing fabrics F1 and F2 might also be called ground fabrics. The piles D1 and D2 are supposed to be separated from each other by a knife K belonging to a not further represented cutting device. Knife K is represented on figure 1 only, but the same kind of cutting device can be used with the other methods of the invention.
Backing fabric F1 includes a binding warp yarn b1 and a filling warp yarn f1. Backing fabric F2 includes a binding warp yarn b2 and a filling warp yarn f2. Alternatively, several filling warp yarns can be used in each backing fabric.
The warp yarns also include pile warp yarns which can extend from one backing fabric to the other, in order to form piles D1 and D2, as represented by pile warp yarn V on figure 1. Other pile warp yarns I, II and III constitute dead pile yarns which remain in baking fabric F1. Similarly, dead pile yarns VI, VII and VIII remain in backing fabric F2.
Binding warp yarn b1 and filling warp yarn f1 together form a group of warp yarn devoted to backing fabric F1. Similarly, binding warp yarn b2 and filling warp yarn f2 together form a group of warp yarns devoted to backing fabric F2. Binding warp yarns and filling warp yarns are drawn in through heddles which are mounted in heddle frames connected to a non represented shedding device, such as a dobby or a cam machine. Pile warp yarns I to III and V to VIII are fed from a creel and drawn in through heddles connected to a non represented Jacquard mechanism.
A top shed is defined between some warp yarns placed by their respective heddles into a top position and a middle position. A bottom shed is defined between some warp yarns placed by their respective heddles into a middle position and a bottom position.
Binding warp yarns, filling warp yarns and pile yarns are grouped into sets which extend side by side in the weft direction, that is in a direction perpendicular to the plane of figure 1. This direction is represented on figure 2 with arrow DE, whereas arrow DA represents a warp direction. Warp direction DA is also represented on figure 1. Directions DA and DE are oriented. In particular, direction DA goes from pick P1 towards pick P32.
All the warp yarns of one set go through the same reed dent space of a reed of the weaving machine. All the warp yarns represented on figure 1, that is binding warp yarns b1 and b2, filling warp yarns f1 and f2 and pile warp yarns I, II, III and V to VIII belong to the same set of warp yarns.
At each pick P1 to P32, at least one weft yarn is inserted in ground fabrics F1 or F2 by two non represented insertion means which travel into the top and bottom sheds.
Weft yarns include inner weft yarns Wi which can also be called "front" weft yarns, since they are oriented, with respect to backing fabric F1 or F2, towards the front of carpet C1 or C2. Weft yarns also include back weft yarns Wb which can also be called "outer" weft yarns, since they are oriented towards the outside of a space defined between backing fabrics F1 and F2 in the configuration of figure 1. Inner weft yarns Wi are located, in each backing fabric on the same side as the piles D1 or D2 with respect to the filling warp yarn f1 or f2. Back weft yarns Wb are located, in each backing fabric F1 or F2, opposite the piles D1 and D2 with respect to the filling warp yarn f1 or f2.
At pick P1, two inner weft yarns Wi are simultaneously inserted in the top backing fabric F1 and in the bottom backing fabric F2. The shedding device, such as the dobby mentioned here-above, places the binding warp yarns b1 and b2 in their middle position. In the top backing fabric F1, the filling warp yarn f1, the dead pile yarns I to III and the patterning pile yarn V are placed in the top position. In the bottom backing fabric F2, the filling warp yarn f2 and the dead pile yarns VI to VIII are placed in the bottom position.
At pick P2, only one back weft yarn Wb is inserted in the top backing fabric F1 whose binding warp yarn b1 and patterning pile yarn V are placed in the top position, whereas the filling warp yarn f1 and the dead pile yarns I to III are placed in the middle position.
At pick P3, two inner weft yarns Wi are simultaneously inserted in the top backing fabric F1 and in the bottom backing fabric F2. The shedding device places the binding warp yarns b1 and b2 in the middle position. In the top backing fabric F1, the filling warp yarn f1 and the dead pile yarns I to III are placed in the top position. In the bottom backing fabric F2, the filling warp yarn f2, the dead pile yarns VI to VIII and the patterning pile yarn V are placed in the bottom position.
At pick P4, only one back weft yarn Wb is inserted in the bottom backing fabric F2 whose binding warp yarn b2 and patterning pile yarn V are placed in the bottom position, while the filling warp yarn f2 and the dead pile yarns VI to VIII are placed in the middle position.
Back weft yarn Wb inserted at pick P4 in lower backing fabric F2 is consecutive to inner weft yarn Wi inserted at pick P3 in backing fabric F2. Similarly, inner and back weft yarns respectively inserted in upper backing fabric at picks P1 and P2, or P5 and P6, are consecutive.
A pick sequence is defined by picks P1 to P4 and this sequence is repeated for picks P5 to P8, P9 to P12 and P13 to P16.
In a first series of weft insertion cycles formed by picks P1 to P16, patterning pile yarn V turns externally around an inner weft yarn Wi of backing fabric F1, at picks P1, P5, P9 and P13 before it turns externally around a consecutive back weft yarn Wb of backing fabric F1, at picks P2, P6, P10 and P14. Similarly, in backing fabric F2, patterning pile yarn V turns externally around an inner weft yarn Wi at picks P3, P7, P11 and P15, prior to turning externally around a consecutive back weft yarn Wb at picks P4, P8, P12 and P16.
During picks P1 to P16, patterning pile yarn V forms successive loops which includes two legs that will form pile D1 or D2 once cut by knife K. Along direction DA, each loop, formed by patterning pile yarn V during picks P1 to P16, successively goes around one inner weft yarn Wi and one back weft yarn Wb on the outer or external side of these weft yarns.
Four picks are necessary to form two pile legs in each backing fabric F1 and F2. This number of picks also defines the length of the pick sequence which is repeated between picks P1 and P16 by the binding warp yarns and the filling warp yarns, as explained here-above. In other words, the Backing Fabric Weave Repeat or "BFWR" equals four.
At picks P17 and P18, the same shed configuration is used and weft yarns are inserted as in picks P1 and P2.
At pick P19, instead of placing patterning pile yarn V in the bottom position, as in pick P3, this yarn is kept in the top position, whereas two inner weft yarns Wi are simultaneously inserted in the top backing fabric F1 and in the bottom backing fabric F2. Binding warp yarns b1 and b2 are placed in the middle position. Filling warp yarn f1 and dead pile yarns I to III are placed in the top position, while filling warp yarn f2 and dead pile yarns VI to VIII are placed in the bottom position.
At pick P20, only one back weft yarn Wb is inserted in the bottom fabric F2, where warp yarn b2 and patterning pile yarn V are placed in the bottom position, whereas filling binding warp yarn f2 and dead pile yarns VI to VIII are placed in the middle position.
A pile yarn leg is formed between picks P16 and P17 and another pile leg is formed between piles P19 and P20.
At pick P21, two inner weft yarns Wi are simultaneously inserted in the top backing fabric F1 and in the bottom backing fabric F2. The shedding device places the binding warp yarns b1 and b2 in the middle position. In the top backing fabric F1, the filling warp yarn f1 and the dead pile yarns I to III are placed in the top position. In the bottom backing fabric F2, the filling warp yarn f2, the dead pile yarn VI to VIII and the patterning pile yarn V are placed in the bottom position.
At pick P22, only one back weft yarn Wb is inserted in the top backing fabric F1 where binding warp yarn b1 and patterning pile yarn V are placed in the top position, whereas filling warp yarn f1 and dead pile yarns I to III are placed in the middle position. A pile yarn leg is formed between picks P21 and P22.
At pick P23, two inner weft yarns Wi are simultaneously inserted in the top backing fabric F1 and in the bottom backing fabric F2. The shedding device places the binding warp yarns b1 and b2 in the middle position. In the top backing fabric F1, filling warp yarn f1, dead pile yarns I to III and patterning pile yarn V are placed in the top position. In the bottom backing fabric F2, filling warp yarn f2 and dead pile yarns VI to VIII are placed in the bottom position.
Thus, a four-pick sequence is defined by picks P20 to P23, with a BFWR equal to four. This four-pick sequence is repeated for picks P24 to P27 and picks P28 to P31.
Inner weft yarn Wi inserted at pick P21 in lower fabric F2 is consecutive to back weft yarn Wb inserted at pick P20 in backing fabric F2. Similarly, back and inner weft yarns respectively inserted in upper backing fabric at picks P22 and P23, or P26 and P27, are consecutive.
Picks P20 to P31 together form a second series of weft insertion cycles where patterning pile yarn V turns first externally around a back weft yarn Wb at picks P20, P24 and P28 in bottom backing fabric F2, before it turns externally around a consecutive inner weft yarn Wi at picks P21, P25 and P29 in this backing fabric. In top backing fabric F1, patterning pile yarn V first turns externally around a back weft yarn Wb at picks P22, P26 and P30 before it turns externally around a consecutive inner weft yarn Wi at picks P23, P27 and P31.
Between picks P20 and P31, patterning pile yarn V also forms loops which define each two pile legs and which go successively around a back weft yarn Wb and an inner weft yarn Wi, along direction DA.
Because of the change of configuration between the first series of picks P1 to P16 and the second series of picks P20 to P31, the piles D1 and D2 formed by patterning pile yarn V take two different slanting orientations once they have been separated from each other by knife K.
One considers pile tufts formed by patterning pile yarn V once carpets C1 and C2 have been separated by knife K. A portion V.1 of yarn V, which has been woven in backing fabric F2 between picks P15 and P17, forms a tuft or loop with two piles D2 slanted in the direction of arrows A1. Actually, portion V.1 is a patterning individual pile tuft of carpet C2 which, along warp direction DA turns externally around inner weft yarn Wi inserted at pick P15 before it runs around back weft yarn Wb inserted at pick P16. Similarly, a portion V.2 of yarn V, which has been woven in backing fabric F2 at picks P19 to P21, forms a tuft or loop with two piles slanted in the direction of arrows A2. Portion V.2 is a patterning individual pile tuft of carpet C2 which, along warp direction DA, turns externally around back weft yarn Wb inserted at pick P20 before it turns around inner weft yarn Wi inserted at pick P21.
Thus, by modifying the path of patterning pile yarn V between the first series of insertion cycles, defined by picks P1 to P16, and the second series of insertion cycles, defined by picks P20 to P31, two slanting orientations of the piles D1 and D2 can be obtained, along warp direction DA, for pile tufts V.1 and V.2.
This change of the slanting orientation of the piles D1 and D2 is obtained without changing the weave pattern of the binding warp yarns b1 and b2 and without changing the weave pattern of the filling warp yarns f1 and f2, which remains the same between picks P1 and P32. In other words, the backing fabric weave structure remains the same for each backing fabric. In particular, the BFWR remains equal to four.
This change of the slanting orientation of piles D1 and D2 along warp direction DA can be obtained by individually driving patterning pile yarn V via the Jacquard mechanism, which means that adjacent pile yarns in the weft direction DE can have different configurations and switch from a first slanting orientation to a second slanting orientation at different locations along the warp direction DA.
It is thus possible to make, via different slanting orientations of the piles D2 of carpet C2 represented on figure 2, a bi-dimensional pattern P, which is formed in a shadow cut pile zone Z and represents a flower in the example, without being limited to strips of slanted piles, as in the prior art. In other words, by proper programming of the Jacquard mechanism driving the patterning warp yarns V of the weaving machine, a cut pile zone with a shadow effect having any bi-dimensional pattern can be produced.
This can be combined with a change of patterning warp yarn, by using one of yarns I to III or VI to VIII instead of pile V for creating piles in different zones of carpets C1 and C2.
In the method of figure 1, patterning pile yarn V follows a path where, in each backing fabric F1 and F2, it turns four times externally around an inner weft yarn Wi prior to externally turning around a consecutive back weft yarn Wb. After pick P19, patterning pile yarn V turns three times in each backing fabric externally around a back weft yarn Wb prior to externally turning around a consecutive inner weft yarn Wi. In practice, in order for the change in the slanting direction or orientation of the piles to be easily visible, the patterning pile yarn turns at least twice externally around an inner weft yarn Wi, then externally around a consecutive back weft yarn Wb in the first series of insertion cycles and at least twice externally around a back weft yarn Wb then externally around a consecutive inner weft yarn Wi in the second series of insertion cycles. When the carpets C1 and C2 are separated by cutting the piles, in each carpet, four consecutive pile tufts V.1 will turn externally around an inner weft yarn Wi prior to externally turning around a consecutive back weft yarn Wb and will be followed by three consecutive pile tufts V.2 which turn externally around a back weft yarn Wb prior to externally turning around a consecutive inner weft yarn Wi.
In this first method, a weft yarn group can be defined by three weft yarns successively introduced within one backing fabric F1 or F2 during four successive picks. For instance, a first weft yarn group is made of the two inner weft yarns Wi introduced in backing fabric F2 at picks P3 and P5 and with the back weft yarn Wb introduced in this backing fabric at pick P4. Another weft yarn group is made of the two inner weft yarns Wi introduced in backing fabric F1 at picks P5 and P7 and of the back weft yarn Wb introduced in this backing fabric at picks P6. In this first method, since a single binding warp yarn, b1 or b2, is used in each backing fabric, F1 or F2, this warp yarn is used to define, in conjunction with the filling warp yarn f1 or f2, some openings where the weft yarns are inserted. At the level of backing fabric F1, binding warp yarn b1 defines a first opening 01, during picks P3 to P5, on the inner side of filling warp yarn f1 and a second opening O1', at pick P6, on the back or outer side of this filling warp yarn. Openings O1 and O1' alternate along warp direction DA, on backing fabric F1. Similarly, two kinds of openings 02 and O2' are defined by binding warp yarn b2 respectively on the inner side and outer side of filling warp yarn f2. Openings O2 and O2' alternate along warp direction DA, on backing fabric F2.
The three weft yarns of a weft yarn group are successively inserted in one opening 01, one opening O1' and another opening O1 in backing fabric F1 and in one opening 02, one opening O2' and another opening 02 in backing fabric F2.
In the second to seventh methods of the invention represented on figures 3 to 8, the same elements as in the first embodiment have the same references. Unless otherwise specified, a method of one of figures 3 to 8, works in the same way as the method of figure 1.
In the second embodiment of figure 3, the patterning weft yarn V follows the same path as in the first embodiment.
The face-to-face weaving machine used with this method also has two non represented insertion means, a first shedding device, for instance a dobby, which can move the binding and filling warp yarns between two positions, and a second shedding device, for instance a Jacquard mechanism, which can move the pile yarns between three positions.
In this embodiment, a pick sequence with a BFWR equal to eight is used. The main difference with the first embodiment is that each backing fabric F1 and F2 includes two binding warp yarns, namely binding warp yarns b1 and b1' in backing fabric F1, binding warp yarns b2 and b2' in backing fabric F2. Binding warp yarns b1 and b1' together define, along warp direction DA successive openings O1 where the three weft yarns of a weft yarn group defined as in the first embodiment are inserted. Similarly, binding warp yarns b2 and b2' together define openings 02 where the three weft yarns of successive weft yarn groups are inserted.
In the third embodiment represented on figure 4, weft yarns are bound in the backing fabrics F1 and F2 on three different levels, in order to increase the slanting effect obtained on the piles D1 and D2.
Inner weft yarns Wi of backing fabric F1 are divided into intermediate weft yarns Wi1 and innermost weft yarns Wi2. Intermediate weft yarns Wi1 are inserted on the pile side of the filling warp yarn f1, between the dead pile yarns I to III and the filling warp yarn f1. Innermost weft yarns Wi2 are inserted between the dead pile yarns I to III and the binding warp yarns b1 or b1'. Similarly, inner weft yarns Wi of lower backing fabric F2 are divided between intermediate weft yarns Wi1 and innermost weft yarns Wi2 defined as for backing fabric F1, but in relation to filling warp yarn f2 and dead pile yarns VI to VIII. In this case, for each pick where two inner weft yarns are inserted, one intermediate inner weft yarn Wi1 and one innermost weft yarn Wi2 are respectively inserted in the upper and lower backing fabrics F1 and F2 or in the lower and upper backing fabrics F2 and F1. The repartition between the intermediate inner weft yarn Wi1 and the innermost weft yarn Wi2 alternates every second pick, when two inner weft yarns are simultaneously inserted.
Patterning pile yarn V turns externally around an intermediate inner weft yarn Wi1, then around a consecutive back weft yarn Wb in a first series of insertion cycles comprised between picks P1 and P12. As from picks P16, patterning pile yarn V turns externally around a back weft yarn Wb before it turns externally around a consecutive intermediate weft yarn Wi1. Patterning pile yarn V does not turn around inner weft yarns Wi2 which cooperate with binding warp yarns b1, b1', b2 and b2'.
The BFWR of this method equals eight. The piles D1 and D2 take a slanting orientation in the direction of arrows A1 and A2, respectively before and after pick P15.
The fourth embodiment represented on figure 5 is globally the same as the one of figure 4, with the same BFWR, but differs for the fact that patterning pile yarn V turns externally around the innermost weft yarns Wi2 instead of the intermediate weft yarns Wi1.
In the embodiments of figures 4 and 5, openings O1 and O2 are defined by two binding warp yarns b1 and b1', b2 and b2' respectively in backing fabrics F1 and F2. Despite inner weft yarns Wi of backing fabric F1 are divided into intermediate weft yarns Wi1 and innermost weft yarns Wi2, the backing fabric weave structure remains the same from pick P1 to pick P32 in each backing fabric.
In the fifth embodiment represented on figure 6, binding warp yarns b1 and b1' of upper backing fabric F1 together form openings O1 where an inner weft yarn Wi and a back weft yarn Wb belonging to a weft yarn group are inserted, respectively on the inner side of filling warp yarn f1 for inner weft yarn Wi and on the back side of this filling warp yarn for back weft yarn Wb. Similarly, a group of an inner weft yarn Wi and a back weft yarn Wb is inserted in a opening 02 defined by two binding yarns b2 and b2' in backing fabric F2. The path of patterning pile yarn V is the same as in the first two embodiments. The BFWR of this method equals 4. The backing fabric weave structure remains the same from picks P1 to pick P32 in each backing fabric.
The backing fabric weave structure used in this embodiment is known as "Rep 2/2".
In the sixth embodiment represented on figure 7, two binding warp yarns b1 and b1' are used in upper backing fabric F1. Each binding warp yarn b1 or b1' follows a pattern in which it remains in the middle position of the shed for seven consecutive picks and changes to the upper position for one pick. The patterns of binding warp yarns b1 and b1' are offset of four picks so that each back weft yarn Wb is bound to the filling warp yarn f1. Two binding warp yarns b2 and b2' are used in lower backing fabric F2 and pattern according to a similar way as in the upper backing fabric F1. The BFWR of this method equals 8.
Between picks P1 and P12, one uses, for patterning pile yarn V, the same kind of path as in the method of figure 1 for the picks P1 to P12. As from pick 13, the patterning pile yarn V form loops which define two pile legs and turn exclusively around back weft yarns Wb. When these pile legs are cut, they define straight piles which are not slanted, and which extend in the direction of arrows A3.
Between picks P20 and P32, one uses, for patterning pile yarn V, the same kind of path as in the method of figure 1 for the picks P20 to P32.
Implementation of the method of figure 7 results in a slanting of the piles D1 and D2 in the direction of arrows A1, from pick P1 to pick P11, and in a slanting of the piles D1 and D2 in the directions of arrows A2, from pick P21 to pick P32.
Figure 8 shows another method where the pile distribution and slanting configuration are different in the upper carpet C1 and in the lower carpet C2. Basically, in the upper carpet, non-slanted piles D1 extend in the direction of arrows A3, whereas, in the lower carpet, slanted piles D2 are obtained in two zones corresponding to picks P7 to P12 and P23 to P32. One notices here that piles D2 are slanted in opposite directions in these two zones, namely the direction of arrows A1 between picks P7 and P12 and in the direction of arrows A2 between picks P23 and P32.
Between picks P7 and P13 in backing fabric F2, patterning pile yarn V turns externally around an inner weft yarn Wi before it turns externally around a consecutive back weft yarn Wb. Between picks P23 and P32, the path of patterning pile yarn V is changed, so that it runs externally around an outer weft yarn Wb before it turns externally around a consecutive inner weft yarn Wi.
The BFWR of this method is the same for upper and lower carpets C1 and C2. It equals eight. The backing fabric weave structure remains the same from pick P1 to pick P32 in each backing fabric.
In all embodiments represented on the figures, warp yarn sets each comprises all the binding warp yarns. However, binding warp yarns used in one backing fabric can be splitted between adjacent warp yarn sets. For example, in the embodiments of figures 3 to 8, two binding warp yarns b1 and b1', b2 and b2' are necessary for forming a backing fabric F1 or F2. One of these binding warp yarns can be drawn in one reed dent, and the other one in another adjacent reed dent.
The invention requires filling warp yarns or tension warp yarns which are more tensioned that binding warp yarns, so that inner weft yarns and back weft yarns are on two different levels in the backing fabric. The methods are independent of the characteristics such as material, color, thickness and count of weft yarns which are used. The same kind of weft yarn can be used for the back weft yarns and the inner weft yarns. In particular, the same kind of weft yarn can be used for the intermediate weft yarn Wi1 and the innermost weft yarn Wi2 of the third and fourth methods.
In the embodiments of the figures 1, 3, 6, 7 and 8, the backing fabrics F1 and F2 incorporate dead pile yarns (I-III, VI-VIII) which are not compulsory.
The invention is not limited to a face-to-face weaving machine with two insertion means and could apply to a face-to-face weaving machine with three or more insertion means which insert simultaneously more than one weft yarn into a backing fabric.
The technical features of the embodiments and alternative embodiments considered here-above can be combined in order to generate new embodiments of the invention.

Claims

Method for simultaneously weaving two pile fabrics (C1, C2) with shadow cut pile zones (Z) on a face-to-face weaving machine, wherein:
- an upper backing fabric (F1) and a lower backing fabric (F2) are woven one above the other with:
- at least one filling warp yarns (f1, f2),

- at least one binding warp yarn (b1, b1', b2, b2'),

- weft yarns (Wi, Wb) inserted in successive weft insertion cycles (P1-P32) between binding warp yarns and filling warp yarns, the weft yarns comprising inner weft yarns (Wi), which are inserted on a pile side of the filling warp yarns, and back weft yarns (Wb), which are inserted on a back side of the filling warp yarns, opposite to the piles (D1, D2) of the fabric,

- patterning pile yarns (V) are interlaced in the upper backing fabric (F1) and in the lower backing fabric (F2), each patterning pile yarn externally turning around an inner and a back weft yarns (Wi, Wb) in each backing fabric,
characterized in that at least one patterning pile yarn (V) follows a path where:
- in a first series of weft insertion cycles (P1-P16; P1-P16; P1-P14; P1-P16; P1-P16; P1-P12; P1-P12) and at least in a first backing fabric (F1, F2), the patterning pile yarn (V) turns externally around an inner weft yarn (Wi) before it turns externally around a consecutive back weft yarn (Wb), and

- in a second series of weft insertion cycles (P20-P32; P20-P32; P15-P32; P17-P32; P20-P32; P20-P32; P24-P32) and at least in the first backing fabric (F1, F2) the patterning pile yarn (V) turns externally around a back weft yarn (Wb) before it turns externally around a consecutive inner weft yarn (Wi).
A method according to claim 1, characterized in that:
- in the first series of weft insertion cycles (P1-P16; P1-P16; P1-P14; P1-P16; P1-P16; P1-P12; P1-P12), the patterning pile yarn (V) turns at least twice externally around an inner weft yarn (W), then externally around a back weft yarn (Wb),

- in the second series of weft insertion cycles (P20-P32; P20-P32; P15-P32; P17-P32; P20-P32; P20-P32; P25-P32), the patterning pile yarn (V) turns at least twice externally around a back weft yarn (Wb), then externally around an inner weft yarn (Wi).
A method according to one of the preceding claims, characterized in that:
- weft yarn groups, made of at least one inner weft yarn (Wi) and of one back weft yarn (Wb), are inserted in at least one backing fabric (F1, F2), in successive weft insertion cycles (P3-P5, P5-P7),

- a single binding warp yarn (b1, b1') is used to bind all weft yarns (Wi, Wb) to the filling warp yarn (f1, f2) in one backing fabric (F1, F2) and

- all weft yarns of a weft yarn group are inserted in openings (01, O1', 02, 02') successively defined by the binding warp yarn and the filling warp yarn.
A method according to one of claims 1 and 2, characterized in that:
- weft yarn groups, made of at least one inner weft yarn (Wi) and of one back weft yarn (Wb), are inserted in at least one backing fabric (F1, F2), in successive weft insertion cycles (P3-P5, P5-P7),

- two binding warp yarns (b1, b1', b2, b2') are used to bind all weft yarns (Wi, Wb) to the filling warp yarns (f1, f2) of one backing fabric (F1, F2) and

- all weft yarns of a weft yarn group are inserted in a single opening (01, 02) defined by the two binding warp yarns.
A method according to claim 4, characterized in that, in a weft yarn group, a first inner weft yarn (Wi), a back weft yarn (Wb) and a second inner weft (Wi) yarn are successively inserted in the backing fabric (F1, F2).
A method according to one of claims 3 to 5, characterized in that each weft yarn group includes a single type of inner weft yarns (Wi) which are inserted between the filling warp yarn (f1, f2) and a binding warp yarn (b1, b1', b2, b2').
A method according to one of claims 3 to 5, characterized in that, in at least the first backing fabric (F1, F2), at least a dead pile (I-III, VI-VIII) yarn is incorporated in the backing fabric and each weft yarn group includes two types of inner weft yarns, namely:
- an intermediate inner weft yarn (Wi1) which is inserted between the filling warp yarn (f1) and the dead pile yarn (I-III, VI-VIII),

- an innermost weft yarn (Wi2) which is inserted between the filling warp yarn (f1, f2) and the binding warp yarn (b1, b1', b2, b2').
A method according to claim 7, characterized in that in the first and second series of weft insertion cycles, the patterning pile yarn (V) externally turns around an intermediate inner weft yarn (Wi1) and around a back weft yarn (Wb).
A method according to claim 7, characterized in that in the first and second series of weft insertion cycles, the patterning pile yarn (V) turns around an innermost weft yarn (Wi2) and around a back weft yarn (Wb).
A method according to any preceding claim, characterized in that the patterning pile yarn (V) follows a path where:
- in the first series of weft insertion cycles (P1-P16; P1-P16; P1-P14; P1-P16; P1-P16; P12-P23; P7-P16) and in both backing fabrics (F1, F2), the patterning pile yarn (V) turns externally around an inner weft yarn before it turns externally around a back weft yarn (Wb), and

- in the second series of weft insertion cycles (P20-P32; P20-P32; P16-P32; P17-P32; P20-P32; P25-P36) and in both backing fabrics (F1, F2), the patterning pile yarn (V) turns externally around a back weft yarn (Wb) before it turns externally around an inner weft yarn (Wi).
A method according to one of claims 1 to 9, characterized in that the patterning pile yarn (V) follows a path which has different first and second series of weft insertion cycles in the upper backing fabric (F1) and lower backing fabric (F2).
A method according to any preceding claim, characterized in that, for some weft insertion cycles (P13-P19), the patterning pile yarn (V) follows a path where it turns around a back weft yarn (Wb) and passes between two inner weft yarns (Wi).
A method according to any preceding claim, characterized in that the backing fabric weave structure, which is defined as the sequence of the consecutive positions of the binding warp yarn (b1, b1', b2, b2') and the filling warp yarn (f1, f2) in the shed, repeats and remains the same in the first and second series of weft insertion cycles.
A pile fabric (C1, C2) with shadow cut pile zones, this fabric including:
- a backing fabric (F1, F2) woven with yarn sets including:
- at least one filling warp yarn (f1, f2),

- at least one binding warp yarn (b1, b1', b2, b2'),

- weft yarns (Wi, Wb) located between the binding warp yarn and the filling warp yarn, the weft yarns comprising inner weft yarns (Wi) which are located on a pile side of the filling warp yarn and back weft yarns (Wb) which are located on a back side of the filling warp yarn, opposite the piles of the fabric,

- pile tufts corresponding each to a patterning pile yarn (V), belonging to a yarn set, interlaced in the backing fabric and forming two pile legs,

characterized in that for at least one yarn set, at least a first pile tuft (V.1) and a second pile tufts (V.2), which are consecutive in a warp direction (DA) of the fabric (F1, F2), are interlaced in the backing fabric in a configuration where:
- in the warp direction, the first pile tuft (V.1) turns externally around an inner weft yarn (Wi) before it turns externally around a consecutive back weft yarn (Wb) and

- in the warp direction, the second pile tuft (V.2) turns externally around a back weft yarn (Wb) before it turns externally around a consecutive inner weft yarn (Wi).
A pile fabric according to claim 14, characterized in that it includes:
- weft yarn groups, made of at least one inner weft yarn (Wi) and of one back weft yarn (Wb), and

- two binding warp yarns (b1, b1', b2, b2') used to bind the weft yarns (Wi, Wb) to the filling warp yarn (f1, f2) and the patterning pile yarn of a yarn set
and in that all weft yarns (Wi, Wb) of a weft yarn group go through an opening (01, 02) formed by the two binding warp yarns.