Knitted device with loops, in particular for forming the female part of a self-adhesive fastener for attaching a motor vehicle seat cover

Abstract

Knitted device (5), in particular a knitted fabric, comprising a first area (6), in particular a rectangular area, from which loops (9) project and at least one second area (7, 8), in particular a contiguous rectangular area, preferably two contiguous areas (7, 8) on either side of the first area (6), the second contiguous border area(s) not including loops (9) and being designed to allow the knitted device to be attached to a cover (4) designed to cover a molded object (1), in particular a motor vehicle seat, for example by stitching, while the first area (6) with loops (9) is designed to cooperate with hooks (14) that project from the molded object (1), characterized in that means are provided to prevent or combat the fraying of the threads of the knitted device (5) forming the one or more second border areas (7, 8).

Claims

1. Knitted device, comprising a knitting fabric having a first area from which loops project and at least one second selvedge area the at least one second selvedge area not comprising loops and being designed to allow the knitted device to be attached to a cover designed to cover a moulded object while the first area with loops is designed to cooperate with hooks that project from the moulded object, the knitted fabric comprising a back formed of interweaving loop wale threads, or columns of stitches, and connecting threads in the weft direction, and, in the first area, of loop threads knitted in the back, each loop being formed by two knitted legs in the back, two strands leaving the two legs and a top connecting the two strands, wherein means are provided to prevent or combat fraying of the threads of the knitted device forming the at least one second selvedge area; and wherein the connecting threads in the weft direction of the back extend in a back-and-forth movement in a transverse direction so as to at least circumvent, block or form a zigzag around, in the machine direction, a number N of rows of columns of stitches where N is between 2 and 5, and this applies across the entire transverse extent of the back of each of the at least one second selvedge area, with the exception of a number N-1 of successive end rows of columns of stitches.

2. Knitted device according to claim 1, characterised in that the means to prevent or combat fraying entail covering the at least one second selvedge area with a coating which provides the at least one second selvedge area considerable dimensional stability and thus prevents fraying of said at least one second selvedge area.

3. Knitted device according to claim 1, characterised in that N is equal to 3.

4. Knitted device according to claim 1, characterised in that anti-fraying means are used such that, a curve giving a force needed to deform the knitted fabric in the crosswise direction (CD) as a function of the deformation between an origin of the coordinates (o, o) and a breaking point R which is at a sudden falling-off of the curve, always remains beneath a straight line connecting the origin and said breaking point R.

5. Knitted device according to claim 4, characterised in that the value of the force at 25% deformation is less than 150 Newtons.

6. Knitted device according to claim 4, characterised in that the value of the force at 50% deformation is less than 350 Newtons.

7. Knitted device according to claim 1, characterised in that it comprises a first central area with loops and two second contiguous selvedge areas on the left and right.

8. Knitted device according to claim 1, characterised in that it is produced on a three-bar loom.

9. Knitted device according claim 1, characterised in that the loop weave is a 10/12// closed-stitch loop weave.

10. Knitted device according to claim 1, characterised in that the loop weave is a 01/21// open loop weave.

11. Moulded object comprising a block made from moulded material having the same shape as the object and a cover covering the block, the cover being attached to the block by cooperation between hooks protruding from the outer surface of the moulded object, and knitted devices according to claim 1 which are attached to the cover.

12. Knitted device, comprising a knitting fabric having a first area from which loops project and at least one second selvedge area, the at least one second selvedge area not comprising loops and being designed to allow the knitted device to be attached to a cover designed to cover a moulded object, while the first area with loops is designed to cooperate with hooks that project from the moulded object, the knitted fabric comprising a back formed of interweaving loop wale threads, or columns of stitches, and connecting threads in the weft direction, and, in the first area, of loop threads knitted in the back, each loop being formed by two knitted legs in the back, two strands leaving the two legs and a top connecting the two strands, wherein means are provided to prevent or combat fraying of the threads of the knitted device forming the at least one second selvedge area; and wherein said knitted fabric is produced on a three-bar loom.

13. Moulded object comprising a block made from moulded material having the same shape as the object and a cover covering the block, the cover being attached to the block by cooperation between hooks protruding from the outer surface of the moulded object, and knitted devices according to claim 12 which are attached to the cover.

14. Knitted device according to claim 4, characterised in that the value of the force at 25% deformation is less than 125 Newtons.

15. Knitted device according to claim 4, characterised in that the value of the force at 25% deformation is less than 100 Newtons.

16. Knitted device according to claim 4, characterised in that the value of the force at 25% deformation is less than 50 Newtons.

17. Knitted device according to claim 4, characterised in that the value of the force at 25% deformation is less than 35 Newtons.

18. Knitted device according to claim 4, characterised in that the value of the force at 50% deformation is less than 300 Newtons.

19. Knitted device according to claim 4, characterised in that the value of the force at 50% deformation is less than 225 Newtons.

20. Knitted device according to claim 4, characterised in that the value of the force at 50% deformation is less than 190 Newtons.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

(2) By way of example, a preferred embodiment of the invention will now be described with reference to the drawings in which:

(3) FIG. 1 is a schematic perspective view of a moulded object in which the cover covering said object is shown at a distance from the moulded object;

(4) FIG. 2 shows a theoretical knitted weave of all threads to be used in the device in FIG. 1, in particular the knitted fabric stitched to the cover in FIG. 1;

(5) FIG. 3 shows a theoretical knitted weave showing only the warp threads or loop wale threads of the knitted fabric in FIG. 2;

(6) FIG. 4 shows a theoretical knitted weave showing only the weft threads of the knitted fabric in FIG. 2;

(7) FIG. 5 shows a theoretical weave showing only the loops of the knitted fabric in FIG. 2;

(8) FIG. 6 shows a second embodiment of the loop weave;

(9) FIG. 7 shows a second embodiment of the loop weave;

(10) FIG. 8 shows a theoretical knitted weave according to an embodiment using the weft weaves in FIG. 4, the columns of stitches in FIG. 3 and the loops in FIG. 7.

(11) FIG. 9 shows a knitted fabric according to yet another embodiment of the invention;

(12) FIG. 10 shows the curve giving the force needed to deform a knitted fabric according to the invention, in other words a knitted fabric comprising the weft threads in FIG. 4, the loop wale threads in FIG. 3 and the so-called open/closed loop threads in FIG. 7 as a function of deformation, particularly between the origin point (0, 0) and the breaking point R, and

(13) FIG. 11 shows the curve giving the force needed to deform a knitted fabric according to the invention, in other words a knitted fabric comprising the weft threads in FIG. 4, the loop wale threads in FIG. 3 and the loop threads in FIG. 5 or FIG. 6 as a function of deformation, particularly between the origin point (0, 0) and the breaking point R.

DETAILED DESCRIPTION OF THE INVENTION

(14) FIG. 1 shows a moulded object in the form of a motor vehicle seat comprising a block 1 made from foam, in particular polyurethane, having the form of a motor vehicle seat and comprising a plurality of trenches 2 at the bottom of which a rectangular strip 3 with hooks 14 to be over-moulded has been attached, in particular by insertion prior to moulding. The moulded object, i.e. the motor vehicle seat, is covered with a cover 4, which perfectly fits the external surface of the block 1. In order to achieve this, the cover 4 is stitched to a knitted device 5, which comprises a central area 6, from which knitted loops 9 project, and two selvedge areas 7 and 8, each of which are stitched to the lower face of the cover 4. When the loops cooperate with the hooks, the cover 4 is attached around the moulded block, fitting its shape perfectly. This thus leads to a moulded object covered with its final cover, for example a motor vehicle seat.

(15) FIGS. 2 to 5 show the weave of a loop knitted fabric produced on a warp loom, which entails working with three guide and tube bars. A first guide bar is used to form loop wales or columns of stitches 10 which cooperate with each row (vertical in the figures) of needles. The second tube bar is used to form weft connections 11 which cooperate with the needles for forming the loop wales 10. A third tube bar is used to form stitches 12 (the legs of the loops) on all needles on a jack bar in the central part of the knitted fabric (rows 7 to 19). The loop thread thus forms the tops 13 of the loops.

(16) The weft connections (FIG. 4) are shown by a non-meshed (weft) system 10. The loop wales, or columns of stitches, may be open or alternate.

(17) Each weft thread, as shown in FIG. 4, extends according to a 00/33// weave. Thus, each weft thread extends in a zigzag in the machine direction (vertical in the figures), passing around three needles of three successive rows in the crosswise direction (from left to right on FIG. 4). In addition, all the rows of needles are thus circumvented/blocked/included in the zigzag by the weft threads, with the exception of the last two columns (24 and 25) which are circumvented/blocked/included in the zigzag by the weft threads on one occasion out of two, and across the entire back of the knitted fabric (rows 1 to 23). Thus, the number of weft threads is equal to the number of rows of columns of stitches minus two. The weft threads are offset by one column. In the event that the zigzag is not formed around three rows, but rather two rows, the number of weft threads is equal to the number of rows of columns of stitches minus one. In general terms, for a zigzag of weft threads formed around N needles (where N is between 2 and 5), the number of weft threads is equal to the number of rows of columns of stitches minus N plus 1. The zigzag extends in the MD direction and is formed on each row of stitches.

(18) 25 columns of needles are shown on the figures. A different number of columns of needles may also be provided depending on the final width of the desired product. FIG. 2 shows how the bar of the columns of stitches works. This is a traditional operation and is not described any further here. The weft weave is shown in FIG. 4. Each weft thread extends in a zigzag around three needles, each zigzag weft thread extends directly after the preceding weft thread. There are thus as many weft threads as columns of stitches or columns of needles, with the exception of the final two columns, which are circumvented/blocked/included in the zigzag on one occasion out of two.

(19) The loop weave shown in FIG. 5 is a closed-stitch loop weave 10/12//.

(20) According to another embodiment shown in FIG. 6, the loop weave is an open loop weave, notably a 01/21// weave.

(21) According to another possible embodiment of the loop weave, a so-called open/closed loop weave is produced, notably a 10/01/21/12// weave.

(22) According to the invention, it is provided that all weft threads extend in a zigzag around three needles and by ensuring that the weft threads extend in succession directly after one another without being separated by a column of stitches or loop wales without any weft.

(23) In addition, the knitted fabric has preferably been produced using only three thread bars. However, the knitted fabric could equally well be produced using a fourth thread distribution bar to produce a weft in the opposite direction, for example an identical weft to that shown in FIG. 4, or, alternatively, a weave with fewer wefts, for example such that one loop wale out of two does not have a weft, or even two loop wales out of three or three loop wales out of four. However, the knitted fabric is preferably produced using only three bars.

(24) In addition, instead of forming a zigzag around three needles, the zigzag could be formed around two needles, and, preferably, between two and five needles. Preferably, 25 columns of needles are provided, and in particular 25 warp threads for a knitted fabric with a width of 40 mm.

(25) Another embodiment of the invention is shown in FIG. 9. The knitted fabric 5 with loops comprises a central area 6 and two selvedge areas 7 and 8. The knitted fabric 5 consists of a back formed by interweaving weft threads and threads with columns of stitches, and, in the central part, loop threads knitted to form loops. The back may be as described previously or may alternatively be different, namely, for example, weft threads which extend in a zigzag across the entire width of the back (as shown on FIG. 9) or over a number of rows in excess of 5. Weft threads may also be provided that do not extend in succession across the entire width of the knitted fabric, for example, by leaving one row out of two or one row out of three without a weft thread. On the other hand, in order to combat fraying, which is likely to arise due to this weft structure, according to the invention it is provided that the selvedge areas may be coated with a hardening glue or resin which will thus protect the knitted fabric from fraying when said fabric undergoes stresses related to the action of hooks on the area with loops on the one hand, and stresses caused by the user.

(26) In particular, it is possible to use a resin that allows mechanical anchoring, for example high-viscosity hot melt adhesive (HMA), for example based on SBC (Styrene Bloc Copolymer), based on polyolefin (PO), based on polyurethane (PU) and/or chemical anchoring. As a variation to FIG. 9, as an alternative or in addition to the layers of resins 15 and 16 with which the selvedges are coated, a thermal stage could be performed, for example by calendering and/or by ultrasonic welding in the selvedge areas to reinforce them and combat fraying which is likely to arise due to this weft structure.

(27) In the embodiments in FIGS. 1 to 8, the anti-fraying means are formed by the defined structure of the background wefts. In FIG. 9, these anti-fraying means are formed by the coating and, in particular, the layers of resins 15 and 16 with which the selvedges are coated. It is thus possible to choose between these two methods in the knowledge that coating is more expensive and more complex to apply. If desired, it is also possible to combine the methods by coating the selvedges of the knitted fabrics in FIGS. 1 to 8 to achieve an even better anti-fraying effect.

(28) FIGS. 10 and 11 shows the curve giving the force needed to deform knitted fabrics in the crosswise direction (CD) according to the invention as a function of the deformation. This curve is traditionally obtained using a dynamometer, in particular by applying the method described in Standard NF EN1415, using the elongation at break test in the CD direction, which entails placing a sample of the knitted fabric between two jaws (distance between the jaws equal to 20 mm) of a dynamometer (traction speed 100 mm/min).

(29) As shown in FIGS. 10 and 11, between the origin of the coordinates (0, 0) and the breaking point R (which can be recognised by a sudden falling-off of the curve, for example a drop in the value of the force in excess of 10%, in particular in excess of 15%), the curve still remains beneath the straight line connecting the origin and point R.

(30) According to the invention, the value of the force at 25% deformation is less than 150 N, preferably less than 125 N, even more preferably less than 100 N, and in particular less than 50 N, or even 35 N.

(31) According to the invention, the value of the force at 50% deformation is less than 350 N, preferably less than 335 N, even more preferably less than 300 N, and in particular less than 225 N, or even 190 N.

(32) As a variation to the embodiment in FIG. 2, loops as shown in FIG. 6 or 7 could be used, for example.

(33) As a variation to the embodiment in FIG. 9, a coating could be used as shown in FIG. 9 and/or a thermal stage could be performed on the selvedges, for example calendering and/or ultrasonic bonding to combat fraying even further.

(34) As a variation to the embodiments in FIGS. 2 to 8, loops as shown in FIG. 5 or 6 could be used, for example.