Method and apparatus for fabricating a three-dimensional warp knitted fabric having varied cross-sections as well as thus obtained fabric

Abstract

 It is aimed to facilitate fabricating of a three-dimensional warp knitted fabric having varied cross-sections, in which a dimension between the front and rear webs and/or convexo-concave patterns on surfaces of the front and rear webs are varied in knitting direction. A double-raschel machine comprised mechanism (11a, 11b; 13a, 13b; 17a, 17b) for moving front and rear intermediate frames (4a, 4b; 5a, 5b) supporting front and rear knitting needles (1a, 1b); controlling unit for controlling the moving of said mechanism for moving, separately between front and rear side; and a plurality of yarn guide bars (18). On proceeding of the knitting, positions and/or an interval of the front and rear knitting needles (1a, 1b) are varied while forming the front and rear webs (a1, a2) and connecting them by connecting yarns.

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for fabricating a three-dimensional warp knitted fabric having varied cross-sections, by a double-raschel machine as well as thus obtained fabric.

Background Art

[0002] Conventionally, the three-dimensional warp knitted fabric having varied cross-sections are knitted by a double-raschel machine having two rows or front and rear rows of knitting needles and having a plurality of yarn guide bars, in correspondence with the two knitting needle rows, for guiding connecting yarns and yarns for forming base webs. When to change a thickness of a fabric to be knitted, it is necessary to change an interval of the front and rear knitting needle rows opposed to each other; therefore, there is needed an apparatus of changing an interval of front and rear knitting-element supporting bodies including the knitting needle rows and front and rear trick plates accompanied thereby.

[0003] The applicant has previously proposed an apparatus of changing an interval between front and rear knitting element supporting bodies as disclosed in, for example, JP-A-2000-80545.

[0004] Further, the proposed apparatus is of an adjusting system in which the trick plate is swung to displace around a supporting lever shaft. Thus, adjusting of a stroke of knitting needles is required for correcting a deviation of the stroke at a front end portion of the knitting needles. In view of this, the applicant has also developed an apparatus of horizontally moving a total of the front and rear knitting-element supporting bodies at above front and rear base tables.

[0005] However, in either of the methods, the interval between the front and rear knitting-element supporting portions is set or changed in accordance with a change in a thickness of to-be knitted three-dimensional, which is allotted for each lot; thus, such setting or changing of the interval is assumed to be done at preparation before starting of the knitting.

[0006] Consequently, a conventional three-dimensional warp knitted fabric, which is fabricated by a double-raschel knitting machine, has an almost constant thickness or a constant interval between front and rear webs; as knitting is made by keeping as constant the interval between the front and rear knitting element supporting bodies, that is, the interval between the front and rear knitting needle rows.

[0007] Thus, conventionally, by varying tension of the yarns fed to the knitting area such as connecting yarns, by varying of knitting pattern or by use of elastic yarns or the like, some variation of the thickness of the three-dimensional warp knitted fabric is induced merely to provide a patterned indented surface. Thus obtained fabric has a relatively small extent of variation in thickness or convexo-concave variation; thus its appearance is poor in ornamental effect. Hence, such fabric is not fully satisfactory. Further, such varying or changing of the tension or of the knitting pattern is troublesome and is not preferable in view of a fabricating efficiency.

[0008] The present invention has been carried out in view of the above to provide a three-dimensional warp knitted fabric having varied cross-sections that has varied thickness or varied interval between front and rear webs, or has varied convexo-concave patterns on a surface. The present invention is especially to provide a method and apparatus for easily fabricating such fabric.

Summary of the Invention

[0009] A method for fabricating a three-dimensional warp knitted fabric having varied cross sections, by use of a double-raschel machine that is comprised of: front and rear knitting needles (1a, 1b); front and rear knitting-elements supporting bodies (4a, 4b; 5a, 5b) for respectively supporting front and rear knitting elements (1a, 1b; 2a, 2b; 3a, 3b) including the front and rear knitting needles; a mechanism (11a, 11b; 13a, 13b; 15a, 15b; 17a, 17b) for moving the front and rear knitting-elements supporting bodies move in a front-rear direction to come close to or go away from each other; control unit for providing control signals to said mechanism for moving; and a plurality of yarn guide bars (18) for guiding yarns for forming front and rear webs (a1, a2) and connecting yarns; and the yarns being fed from the yarn guide bars (18) to the front and rear knitting needles (1a, 1b) so that the front and rear webs (a1, a2) are formed and simultaneously connected by the connecting yarns on proceeding of knitting; wherein on the proceeding of the knitting, positions of and/or an interval between the front and rear knitting needles (1a, 1b) are varied by said mechanism for moving (11a, 11b; 13a, 13b; 15a, 15b; 17a, 17b), so that convexo-concave patterns on surfaces of the front and rear webs and/or a dimension between the front and rear webs are varied in the three-dimensional warp knitted fabric knitted in a single continuous knitting process.

[0010] According to the above fabricating method, the three-dimensional warp knitted fabric having so-to-speak varied cross sections can easily be knitted to be fabricates, because a dimension between the two front and rear webs of the three-dimensional warp knitted fabric to be knitted, that is, the thickness and/or the shapes of recesses and projections of the surfaces of the webs can pertinently be changed in the knitting direction.

[0011] In the above fabricating method, by making totals of the front and rear knitting element supporting bodies supporting the knitting elements of the knitting needles or the like remote from each other and proximate to each other in the front and rear direction, the positions and the interval of the front and rear knitting needles may be changed by horizontal movement. It is not necessary to correct a deviation of a stroke at a distal end portion of the knitting needle; and therefore, the interval between the two knitting needles in knitting can easily be changed. Consequently, the method of the invention can be embodied without a problem.

[0012] In the above-described fabricating method, the front knitting needles (1a) along with the front knitting-elements supporting bodies (4a, 5a) are moved as controlled separately, to the rear knitting needles (1b) along with the rear knitting-elements supporting bodies (4b, 5b), so that cross sections are symmetrical or asymmetrical between front and rear surfaces in the three-dimensional knitted fabric. Thus, the positions of the front and rear knitting needles for knitting the front and rear webs can be changed separately; and therefore, it is facilitated to produce not only the three-dimensional warp knitted fabric that is symmetrical between the front and rear webs but also ones that is asymmetrical between the front and rear webs and has different convexo-concave patterns on the front and rear webs.

[0013] Further, it is preferable to further comprise a guide-bar swinging element (20) for holding the yarn guide bars (18), wherein, on proceeding of the knitting, the guide-bar swinging element is moved to swing the guide bars in the front-rear direction by guide-bar swinging mechanism (24) connected to a supporting body above a knitting area; and a position of the guide-bar swinging element (20) is controlled such that a position of swinging a yarn guiding needle (18a) at a distal end of the yarn guide bar is disposed substantially at a center between the two contiguous knitting needles, in response to varying in positions of and/or an interval between the front and rear knitting needles (1a, 1b). By such construction, the guide bar swinging width is considerably increased, even when the interval between the front and rear knitting needles is increased; knitting is carried out by passing each of the yarn guiding needles on yarn guide bars through the center position between the contiguous two knitting needles, in the front and rear direction.

[0014] An apparatus for fabricating a three-dimensional warp knitted fabric having varied cross sections, formed of a double-raschel machine, comprising: front and rear knitting needles (1a, 1b); front and rear knitting-elements supporting bodies (4a, 4b; 5a, 5b) for respectively supporting front and rear knitting elements (1a, 1b; 2a, 2b; 3a, 3b) including the front and rear knitting needles; a mechanism (11a, 11b; 13a, 13b; 15a, 15b; 17a, 17b) for moving the front and rear knitting-elements supporting bodies move in a front-rear direction to come close to or go away from each other; control unit for providing control signals to said mechanism for moving; and a plurality of yarn guide bars (18) for guiding yarns for forming front and rear webs (a1, a2) and connecting yarns; wherein said mechanism for moving (11a, 11b; 13a, 13b; 15a, 15b; 17a, 17b) is constructed to be able to vary positions and/or an interval of the front and rear knitting needles (1a, 1b) on receiving of the control signals from the control unit, while proceeding of the knitting.

[0015] According to the above fabricating apparatus, obtainable by the knitting is the three-dimensional warp knitted fabric having the varied cross sections in which the thickness or the shapes of recesses and projections of the surfaces differs. The mechanism for moving may be constructed to control moving of the front and rear knitting element supporting bodies separately between front and rear sides. Then, easily obtainable is an asymmetric three-dimensional warp knitted fabric in which convexo-concave patterns on surfaces of the front and rear webs differ from each other; thus it is preferable in embodying the invention.

[0016] Particularly preferably, the above-described fabricating apparatus further comprises a guide-swinging element for holding the respective yarn guide bars. The guide-swinging element is provided to move distal end parts of the yarn guide bars to swing substantially along a straight line in the front-rear direction relative to the front and rear knitting needles, by guide-bar swinging mechanism that is interposed between the guide-bar swinging element and a supporting body above a knitting area.

[0017] Thereby, the yarn guide bar for guiding the web forming yarns or the connecting yarns swings at always substantially the same vertical position relative to the front and rear knitting needles, even when the positions and the intervals of the front and rear knitting needles are changed. Even when the interval between the front and rear knitting needles is large, the yarn guiding needle on the yarn guide bar can be passed between the knitting needles in the same relationship to the front and rear knitting needles. Thus, it is facilitated to form the three-dimensional warp knitted fabric having the varied cross sections.

[0018] For example, the guide-bar swinging mechanism comprises a sliding support portion for slidably supporting the guide-bar swinging element in the front and rear direction orthogonal to the front and rear knitting needles; and driving mechanism for sliding the slidably supported guide-swinging element in synchronism with knitting operation of the knitting machine; wherein a front end of each yarn guide bar is linearly moved by the driving mechanism.

[0019] The guide-bar swinging mechanism may be comprised of a four-shafts link mechanism constituted by; a supporting arm fixedly provided to a supporting body above a knitting area; an arm remote from the supporting arm in a lower direction and connected to the guide-bar swinging element; first and second supporting shafts arranged at the supporting arm; first and second swinging shafts arranged at the arm; first and second links for respectively connecting the first supporting shaft to the first swinging shaft as well as the second supporting shaft to the second swinging shaft. At least one of the first and the second supporting shafts is connected with rotation driving means for rotating the supporting shaft pertinently in synchronism with knitting operation of the knitting machine; the supporting shaft is fixedly connected with one of the first and the second links, and distal end of the yarn guide bar is linearly moved by the rotational driving mechanism.

[0020] The invention-wise three-dimensional warp knitted fabric is fabricated by the fabricating method, wherein a thickness between front and rear webs and/or shapes of recesses and projections of surfaces of the front and rear webs are varied in a knitting direction.

[0021] The three-dimensional warp knitted fabric is excellent in fanciness or ornamental appearance or appeal due to the variation in the thickness and/or patterns of recesses and projections of the surfaces. Properties such as elasticity, pressure resistance or the like may be varied locally or on area-to-area base, so that the fabrics are applicable for interior goods, sheets, cushions and the like.

Brief Description of the Drawings

[0022] 

Fig. 1 is a side sectional view showing an outline of a double-raschel machine, which constitutes an apparatus of fabricating a three-dimensional warp knitted fabric having varied cross-sections, according to a first embodiment of the invention;

Fig. 2 is a front view of that shown above, as partially omitting a part associated with an actuator lever;

Fig. 3 is a front view in same manner as above, as partially omitting a part associated with an actuator lever and showing a modified example in respect of a portion for driving an actuator shaft;

Fig. 4 is an enlarged explanatory view showing a manner of moving of a yarn guide bar relative to front and rear knitting needles;

Fig. 5 is a side sectional view showing an outline of a double-raschel machine constituting an apparatus according to a second embodiment of the invention;

Fig. 6 is a sectional view taken along a line VI-VI of the double-raschel machine of Fig. 5;

Fig. 7 is a sectional view taken along a line VII-VII of the double-raschel machine of Fig. 5;

Fig. 8A is a schematic front view showing an outline of an apparatus of producing a displacement in a width direction of a knitting machine relative to a yarn guide bar at a side portion of the knitting machine.

Fig. 8B is an explanatory view of a state of shifting a position by swinging a guide bar by a rod of the apparatus of producing the displacement.

Fig. 9A, Fig. 9B and Fig. 9C are schematic sectional perspective views respectively showing examples of varied cross-section three-dimensional warp knitted fabrics according to the invention.

Fig. 10A, Fig. 10B, Fig. 10C and Fig. 10D are schematic sectional perspective views respectively showing other examples of varied cross-section three-dimensional warp knitted fabrics according to the invention.

Fig. 11A, Fig. 11B, Fig. 11C and Fig. 11D are schematic sectional perspective views respectively showing still other examples of varied cross-section three-dimensional warp knitted fabrics according to the invention.

Best Mode for Carrying Out the Invention

[0023] An explanation will be given of embodiments of the invention along with examples of the apparatus shown in the drawings, as follows.

[0024] Fig. 1 through Fig. 3 show an apparatus, according to a first embodiment of the invention, for fabricating a three-dimensional warp knitted fabric having varied cross-sections. Among them, Fig. 1 is a side sectional view showing an outline of a double-raschel machine constituting the fabricating apparatus; Fig. 2 is a front view of that shown above, as partially omitting a part associated with an actuator lever; and Fig. 3 is a sectional view showing a modified example in respect of a portion for driving an actuator shaft.

[0025] In the drawings, notation 1a designates a front knitting needle, notation 1b designates a rear knitting needle, and numbers thereof are arranged respectively in line along a width direction of a knitting machine (direction orthogonal to paper face of Fig. 1) to constitute front and rear knitting needle rows. Notation 2a designates a front trick plate, notation 2b designates a rear trick plate, and respective ones thereof are extended in the width direction of the knitting machine in correspondence with the knitting needle rows. Notation 3a designates a front stitch comb, notation 3b designates a rear stitch comb, and respective ones thereof are arranged respectively in line along the width direction of the knitting machine in correspondence with the knitting needle rows.

[0026] Notation 4a designates an intermediate frame at front or a member at front side for supporting so-to-speak knitting elements such as the knitting needles or the knitting needle row, the trick plate, the switch comb, a tong, and a sinker. Notation 4b designates an intermediate frame at rear or a member at rear side for supporting the knitting elements. Pluralities of the front and rear intermediate frames 4a, 4b are erected to fix onto a front base table 5a and a rear base table 5b, as opposed with each counterpart in front-rear wise direction and as spaced apart in the width direction of the knitting machine. The intermediate frames 4a, 4b are installed respectively at a front side and a rear side of a foundation trestle 6 movably in a front and rear direction of the knitting machine, or left and right direction of paper face of Fig. 1. The pair of intermediate frames 4a, 4b at front and rear, together with knitting elements thereof, come closer or go away from each other, by moving of the front base table 5a and by moving of the rear base table 5b.

[0027] Upper portions of the front and rear intermediate frames 4a, 4b are penetrated by supporting shafts 7a, 7b respectively in the width direction of the knitting machine. Attached respectively on the front and rear supporting shafts 7a, 7b are the front and rear knitting elements, via holding members such as levers or the like. The front and rear knitting elements, such as the front and rear knitting needles or the knitting needle rows, the front and rear trick plates, and the front and rear stitch combs are driven by rotating cam shafts 8a, 8b, via not-illustrated cam levers, in a same manner with conventional machine; so that predetermined swinging and up-down movement for knitting are induced. Normally, it is constructed such that the knitting needle row swings in the direction opposed to that of swinging movement of a yarn guide bar to be mentioned later. Such construction does not constitute the gist of the invention and therefore, detailed illustration and explanation thereof will be omitted.

[0028] An explanation will be given of a mechanism for moving the front base table 5a and the rear base table 5b, in the front and rear direction to be remote from each other and proximate to each other; in other words a mechanism for moving the intermediate frames 4a and 4b thereabove along with the front and rear knitting elements supported thereby.

[0029] The front base table 5a and rear base table 5b are supported movably in the front and rear direction in a manner as; guides 9a, 9b on lower faces of the base tables 5a, 5b are respectively engaged with front and rear linear guides 10a, 10b on an upper face of the foundation trestle 6. Meanwhile, screw shafts 11a, 11b extended in the front and rear direction are arranged between the lower faces of the front base table 5a and the rear base table 5b, respectively, and the upper face of the foundation trestle 6, at required locations in the width direction of the knitting machine. The screw shafts 11a, 11b are respectively supported by bearings 12a, 12b fixed on a front-end portion and a rear end portion of the foundation trestle 6. The screw shafts 11a, 11b are screwed to nuts 13a, 13b that are respectively fixed on lower faces of the front base table 5a and the rear base table 5b.

[0030] Bevel gears 14a and 14b are respectively fixed to an end portion of the front screw shaft 11a, which projects frontward from the front base table, and an end portion of the rear screw shaft 11b, which projects rearward from the rear base table. The bevel gears 14a and 14b are brought in mesh with bevel gears 16a, 16b on power transmission shafts 15a, 15b. The power transmission shafts 15a, 15b are respectively connected to motors 17a, 17b for driving, via some power transmission mechanisms in accordance with situation. That is, the screw shafts 11a, 11b are respectively rotated via the bevel gears 14a, 14b and 16a, 16b on the power transmission shafts 15a, 15b by rotational drive forces of the motors 17a, 17b. Consequently, the front base table 5a and the rear base table 5b are respectively moved linearly in the front and rear direction of the knitting machine in proportion to the rotation.

[0031] The motor 17a, 17b are respectively driven as properly controlled by move-wise control signals from a not-illustrated control unit so that the move the front base table 5a and the rear base table 5b are controlled.

[0032] In an illustrated example, the front and rear screw shafts 11a, 11b, which are for moving the front and rear intermediate frames 4a, 4b supporting the knitting elements, are constituted separately as to separately control moving of the front and rear base tables 5a and 5b. In otherwise, the front and rear screw shafts 11a, 11b may be connected to each other by a coupling or the like. In this case, the screw shafts 11a, 11b are threaded as righthand and left-hand as inverse to each other so that clockwise or anti-clockwise rotation of the shafts induces simultaneous moving of the front and rear base tables 5a and 5b as to come close to and go away from each other. In practice, it is preferred to enable separate controlling in respect of each of the screw shafts 11a, 11b as previously described, because this enables knitting to form the three-dimensional warp knitted fabric that has different indented patterns between front and rear faces and has cross sections asymmetrical in front and rear.

[0033] Numeral 18 designates a plurality of yarn guide bars for respectively guiding yarns for forming front and rear webs and connecting yarns. Each of the yarn guide bars 18 is provided with yarn guiding needles 18a at distal end thereof, in correspondence with the front knitting needles 1a or the rear knitting needles 1b. The yarn guide bars 18 are front-rear wise arrayed or overlapped, at above a knitting area consisting of the knitting needles 1a, 1b or knitting needle rows. The number of the yarn guide bars 18 may be increased or decreased in accordance with to-be knitted three-dimensional fabric. The number may be increased even to 20 or more.

[0034] Numeral 20 designates a guide-bar swinging element comprising an arcuate shaped mounting brace 21 to which each of the yarn guide bars 18 is attached and a link 22 extended upward from the mounting brace 21. Each of the yarn guide bars 18 is displaceable in its longitudinal direction because a pin 19 is projected from an inverse-T shaped mounting strip 18b located on top of the guide bar 18 and is attached to the mounting brace 21 through a not-illustrated stroke bearing. In this way, predetermined shogging motion may be imparted to the guide bar at a side part on the knitting machine.

[0035] At above the knitting area, the guide-bar swinging element 20 is connected to a supporting body 23, such as a traverse, which is extended in the width direction of the knitting machine, via guide-bar swinging mechanism 24 to be mentioned later. As schematically shown in Fig. 4, the guide-bar swinging mechanism 24 imparts swinging along a straight line in the front and rear direction orthogonal to rows of the front and rear knitting needles 1a, 1b as in arrows of Fig. 4, to the guide bars 18 so as to accordingly move the yarn guiding needles 18a at distal ends of the yarn guide bars 18. Normally, a plurality of the guide-bar swinging elements 20 are distributed in the width direction of the knitting machine to be spaced go away from each other at predetermined intervals. Onto the plurality of guide-bar swinging elements 20, each of the yarn guide bars 18 is attached.

[0036] The guide-bar swinging mechanism 24 may be embodied in various manners other than the above-described, and may imparts, for example, a motion along an arcuate line, to the guide bars. Nevertheless, in the first embodiment, a swinging motion along a straight line is imparted.

[0037] A linear guide 25 is attached as a slide support, onto a lower face of the supporting body 23 having a section in a rectangle shape so that the linear guide is arranged in the front and rear direction or width direction of the supporting body 23. A lower portion of the linear guide 25 is widened in its cross section. An upper end portion 22a of the link 22 of the guide-bar swinging element 20 is supported by and engaged with the linear guide 25 as to be able to slide in the front and rear direction relative to the linear guide 25 and as not to come off downward.

[0038] For driving the guide-bar swinging element 20, one end portion of a connecting strip 27 is attached as hinged to a portion of the link 22; and other end portion of the connecting strip 27 is connected to and hung from a lower end portion of an actuator lever 29, which is supported by and hinged on a hinging support shaft 28, through a pin as a connecting element. An actuator piece 32 is attached, through an eccentric cam mechanism 31, to an actuator shaft 30 that is arranged in the width direction of the knitting machine at inside of the supporting body 23. A projection 32a of the actuator piece 32 is projected through an opening 33 opened at a side face of the supporting body 23 and is coupled to a middle portion of the actuator lever 29 through a pin 34 as a connecting element.

[0039] Thus, the guide-bar swinging element 20 is displaced in the front and rear direction by front-rear-wise motion of the projection 32a accompanied with rotation of the actuator shaft 30. The front-rear-wise motion causes swinging of the actuator lever 29 around the hinging support shaft 28 and then moving the connecting strip 27 as to cause such displacement of the guide-bar swinging element 20.

[0040] Normally, the actuator shaft 30 is controlled to rotate in synchronism with operation of the knitting machine. For example, when a motor 35 for driving is connected to an end portion of the actuator shaft 30 as shown by Fig. 2, the motor 35 is pertinently controlled by a control signal from the control unit to thereby control the rotation of the actuator shaft 30.

[0041] In otherwise, the actuator shaft 30 may be controlled as in an example shown in Fig. 3. A pulley 36 is attached on an end of the actuator shaft 30. A power transmission belt, which is preferably a timing belt, is wound around between the pulley 36 and another pulley 38 that is attached on the camshaft 8a or 8b of the knitting machine or on an intermediate shaft rotated in synchronism with the camshaft 8a or 8b. In this way, rotation of the camshaft 8a or 8b is directly or indirectly transmitted to the actuator shaft 30.

[0042] In following, an explanation will be given to a manner of knitting the three-dimensional warp knitted fabric having varied cross-sections, by use of the fabricating apparatus of the first embodiment.

[0043] Notation "A" in Fig. 1 designates a three-dimensional warp knitted fabric having varied cross-sections which is being knitted. When the knitting machine is in operation, the knitting needles 1a, 1b carry out predetermined knitting movement such as up-down and swinging motion. Simultaneously therewith, as shown by the arrows in Fig. 4, the guide-bar swinging element 20 thereabove carries out guide-swinging movement in the front and rear direction in synchronism with the knitting movement by being driven by the actuator shaft 30 in the guide-bar swinging mechanism 24. The guide-swinging movement is carried out particularly by the linear guide 25 in the guide-bar swinging mechanism 24. The respective yarn guide bars 18 attached to the guide-bar swinging element 20 moves along a straight line in the front and rear direction orthogonal to the rows of front and rear knitting needles 1a, 1b, as indicated by solid-line and chained-line arrows on Fig. 4. Thereby, the front and rear webs a1, a2 are respectively knitted by the web forming yarn guided by the respective yarn guide bars 18 and the front and rear webs are connected as knitted together by the connecting yarn.

[0044] When knitting the three-dimensional warp knitted fabric A, the control unit sends control signals in accordance with a shaping or conformation of the knitted fabric A, to the motor 17a, 17b for respectively driving the front and rear screw shafts 11a, 11b, which are respectively for moving the front base table 5a and the rear base table 5b in the front and rear direction. On course of the knitting, rotation of the screw shafts 11a, 11b is controlled at pertinent extents, and thereby the front and rear base tables 5a, 5b are moved correspondingly; so that the front and rear intermediate frames 4a, 4b for supporting the knitting elements including the front and rear knitting needles 1a, 1b are respectively moved in desired directions and in desired extents. Thus, fabric A is knitted while pertinently changing or adjusting the positions and/or the interval of the two knitting needles 1a, 1b.

[0045] Moving directions and moving distances of the two intermediate frames 4a, 4b, that is, the two knitting needles 1a, 1b may be set or selected in various manner by the control signals from the control unit. The front and rear knitting needles 1a, 1b may be simultaneously moved in front and rear opposite directions by the same distance. Other than such manner of moving, only either one of the front and rear knitting needles 1a, 1b may be moved. In otherwise, they may be moved in same direction, or by different distance; or any combinations of these may be adopted. Thus, changing the positions or the interval of the two knitting needles 1a, 1b is facilitated on course of knitting the fabric.

[0046] This enables changing of dimension between the front and rear webs, that is, a thickness and/or convexo-concave patterns on surfaces of the front and rear web a1, a2. Thus, as shown by Fig. 9 through Fig. 11, the three-dimensional warp knitted fabric "A" having symmetric or asymmetric varied cross sections in knitting direction may be fabricated, in same manner with conventional or normal three-dimensional warp knitted fabric.

[0047] For example, the positions or the interval of the front and rear knitting needles 1a, 1b may be changed symmetrically in the front and rear direction on course of the knitting. Then, as shown by Fig. 9A, Fig. 9B and Fig. 9C, the three-dimensional warp knitted fabrics "A" are fabricated in which convexo-concave patterns on surfaces of the front and rear web a1, a2 are symmetrical between the webs. In otherwise, the interval by changing position of either one of the front and rear knitting needles 1a, 1b, on course of the knitting. Then, as shown by Fig. 10A, Fig. 10B, Fig. 10C and Fig. 10D, he three-dimensional warp knitted fabrics "A" are fabricated in which convexo-concave pattern is formed on only one of the front and rear webs a1, a2. Further in otherwise, positions or the interval of the front and rear knitting needles 1a, 1b may be changed asymmetrically in the front and rear direction on course of the knitting. Then, the three-dimensional warp knitted fabrics "A" as shown by Fig. 11A, Fig. 11B, Fig. 11C and Fig. 11D are fabricated.

[0048] In the above, the respective yarn guide bars 18 attached to the guide-bar swinging elements carry out guide-bar swinging movement along a straight line in the front and rear direction orthogonal to the rows of front and rear knitting needles 1a, 1b. Thus, regardless of the extent of change in the interval between the front and rear knitting needles 1a, 1b, relationships between the front and rear knitting needles and the yarn guiding needles 18a on distal end of the yarn guide bar 18 are kept constant when passing the yarns between them. Thus, it is facilitated to fabricate the three-dimensional warp knitted fabrics in which the dimension between the front and rear webs, that is, thickness are varied, or in which the convexo-concave patterns on surfaces are varied.

[0049] Fig. 5 through Fig. 7 show a second embodiment of the invention-wise apparatus for fabricating three-dimensional warp knitted fabric having varied cross sections. Fig. 5 thereamong is a side sectional view showing an outline of a double-raschel machine constituting the fabricating apparatus. Fig. 6 is a sectional view taken along a line VI-VI of the same, and Fig. 7 is a sectional view taken along line VII-VII of the same.

[0050] The apparatus of the second embodiment is modified from that of the first embodiment in respect of the guide-bar swinging mechanism 24 that imparts swinging movement to the guide-bar swinging element 20 holding the every yarn guide bars 18.

[0051] In this embodiment, other basic structure or mechanisms are same such as mechanism for moving the intermediate frames 4a, 4b, which support the knitting elements including the knitting needles 1a, 1b, as to come closer to or go away from each other. Thus, elements appeared in the first embodiment are allocated with same notations or numerals; and an explanation thereof will be omitted.

[0052] According to the guide-bar swinging mechanism 24 of the apparatus of the second embodiment, a supporting arm 40 extended in either of the front and rear direction is fixed at a lower face of the supporting body 23 that has a rectangular cross section and is located at above the knitting area. Moreover, a first supporting shaft 41 and a second supporting shaft 42 respectively extended in the width direction of the knitting machine are rotatably inserted, via bearings 43, 44, in through holes on a middle portion and a front end portion of the supporting arm 40 in respect of its extending direction; and the first and second the direction of extending of the supporting arm 40 supporting shafts 41, 42 are spaced go away from each other by a necessary interval.

[0053] Meanwhile, the guide-bar swinging element 20 comprises the arcuate-shaped mounting brace 21 and a connecting arm 45 that is connected to the mounting brace 21 and is bent and extended in a direction same as that of the supporting arm 40 in either of the front and rear direction. The connecting arm 45 is spaced go away from the supporting arm 40 as located on a slightly lower side thereof. In the case of the drawing, the connecting arm 45 bends at a middle portion thereof to constitute substantially V-like shape in view from a side direction of the knitting machine. The bent portion and a distal end portion of the connecting arm 45 are pivotably arranged with a first swinging shaft 46 and a second swinging shaft 47, which are rotatable about axes in parallel with the first supporting shaft 41 and the second supporting shaft 42.

[0054] The supporting arm 40 and the connecting arm 45 are combined as to jointly form a four-shafts link mechanism, by which the first supporting shaft 41 and the first swinging shaft 46 are connected by a first link member 48 and the second supporting shaft 42 and the second swinging shaft 47 are connected by a second link member 49.

[0055] At least one of the first and second link members 48,49, for example, the first link member 48 is connected to the first supporting shaft 41. The supporting shaft 41 is driven to rotate in clockwise and anti-clockwise direction within a required angle. Then, the first link member 48 is pivoted in the front and rear direction of the knitting machine centering on the supporting shaft 41; in accordance therewith, the second link member 49 is pivoted centering on the second supporting shaft 42. The connecting arm 45 and therefore, the guide-bar swinging element 20 pivots to be displaced in the front and rear direction of the knitting machine in synchronism with the knitting operation of the knitting machine.

[0056] In respect of the guide-bar swinging element 20, a moving range or distance of a pivoting displacement and a manner of moving are easily modified or selected by adjusting: a rotational angle of the first supporting shaft 41; positions or an interval of the first and second supporting shafts 41 42 on the supporting arm 40; positions and an interval of the first and second swinging shafts on the arm 45; lengths of the first and second link members 48, 49 and the like. For example, the guide-bar swinging element 20 and therefore, the respective yarn guide bars 18 attached and held thereby may be moved substantially along a straight line substantially in the horizontal state.

[0057] For clockwise or anticlockwise rotating of the first supporting shaft 41, in a case shown by Fig. 5 and Fig. 6, a lever 50 is fixed to the supporting shaft 41; a connecting rod 51 axially supported by and connected to the lever 50 is connected to the cam shaft 8a of the knitting machine; and the first supporting shaft 41 may rotate clockwise or anticlockwise by required angles in accordance with rotation of the cam shaft 8a as its rotation causes moving of the connecting rod 51 in the up and down direction and then motion is transmitted through a lever 50 to the first supporting shaft 41.

[0058] For driving of clockwise or anticlockwise rotation of the first supporting shaft 41, he lever 50 and the connecting rod 51 may be omitted so that the first supporting shaft 41 may be driven to rotate clockwise or anticlockwise directly by driving unit such as a servomotor (not illustrated).

[0059] Also in the case of the fabricating apparatus according the second embodiment, similar to the case of the first embodiment, the knitting needles 1a, 1b carry out predetermined knitting movement; simultaneously therewith, the guide-bar swinging element 20 thereabove carries out movement of pivoting to displace in the front and rear direction of the knitting machine in response of clockwise or anticlockwise rotating of the first supporting shaft 41 in the guide-bar swinging mechanism 24, through working of the 4 shafts link mechanism constituted by the supporting arm 40, the arm 45, the first and second supporting shafts 41, 42, and the first and second swinging shafts 46, 47. Accordingly, the yarn guide bars 18 attached to the guide-bar swinging element 20 carry out guide-bar swinging movement in the front and rear directions substantially orthogonal to the rows of front and rear knitting needles 1a, 1b. Thereby, the front and rear webs a1, a2 are formed by the web forming yarns guided by the respective yarn guide bars 18; and the front and rear webs are knit-wise connected by the connecting yarn.

[0060] In course of the knitting operation, the positions and/or the interval of the front and rear knitting needles 1a, 1b is shifted as required by respectively moving the front and rear intermediate frames 4a, 4b, which is for supporting the knitting elements including the front and rear knitting needles 1a, 1b, in arbitrary directions and to arbitrary positions. Similar to the case of the first embodiment, the three-dimensional warp knitted fabric A having the various patterns of varied cross-sections exemplified in Fig. 9 through Fig. 11 are fabricated; in which the dimension between the front and rear webs (thickness) and/or the convexo-concave patterns the surfaces of the front and rear webs are varied in the knitting direction; as easily to the case of the normal three-dimensional warp knitted fabric.

[0061] Fig. 8A and Fig. 8B show a specific example for keeping each of the yarn guiding needles 18a substantially at centers between one and next one of the knitting needles 1a, 1b while swinging of the yarn guiding needles 18a, as to cope with variation in the positions and/or the interval of the front and rear knitting needles 1a, 1b. This specific example is applicable to both of the first and second embodiments.

[0062] In the figure, numeral 55 designates a displacement generating device for imparting a displacement in the width direction of the knitting machine, or shogging movement, to the yarn guide bars 18 from one side portion of the knitting machine, in accordance with a knitting pattern. The displacement generating apparatus 55 is provided with a plurality of pairs of connecting pins 57 that are moved forward and rearward respectively by not-illustrated ball screws and servomotors 56 in correspondence with the respective yarn guide bars 18. An attaching member 58 is disposed on distal ends of each pair of the connecting pins 57; and the attaching member 58 is connected through a rod 59, to respective mounting strip 18b in the inverse-T shape arranged on an end portion of respective one of the yarn guide bar 18. Required displacement is imparted to each yarn guide bar 18 by driving of the respective servomotor 56.

[0063] In the above, when the rod 59 is positioned to be parallel with a longitudinal direction of the guide bars the rod 59 is inclined on guide-bar swinging movement by an amount of, for example, a width and thus is brought into a state of Fig. 8B, if the yarn guiding needles 18a on the yarn guide bars 18 are disposed substantially at equidistance from two successive knitting needles 1a or 1b in the front or rear knitting needle rows. As a result of inclining of the rod 59, a position of the yarn guide bar 18 is deviated in the longitudinal direction of the guide bar by an amount of a dimension "C" on the figure. The larger the swinging width of the guide bar, the larger becomes such shift.

[0064] Therefore, when the interval between the front and rear knitting needles 1a, 1b is increased, there is a concern that the yarn guiding needles 18a are shifted from substantially the centers between the two knitting needles 1a, or 1b contiguous to each other in the front or rear knitting needle rows to be brought into contact with the knitting needles by being influenced by the positional shift of the yarn guide bars 18 in the longitudinal direction of the guide bar.

[0065] Hence, the knitting is carried out such that in correspondence with the deviation in the positions and/or the interval of the front and rear knitting needles 1a, 1b, the servomotor 56 is driven as controlled to cancel the positional deviation, by pertinent control signals from the control unit. Swinging positions of the yarn guiding needles 18a on the respective yarn guide bars 18 are disposed substantially at the centers between the two successive knitting needles 1a or 1b in the front or rear knitting needle rows. Thereby, the knitting is facilitated even when the interval between the front and rear knitting needles 1a, 1b is considerably large, or the knitting needles are considerably displaced in one direction in the front and rear direction. Thus, it is facilitated to fabricate the above-described three-dimensional warp knitted fabrics having the varied cross sections.

[0066] In the illustrated embodiments, an explanation has been given of the case of forming the knitting needle rows by the front and rear knitting needles 1a, 1b as well as the case of carrying out the knitting by making the yarn guide bar 18 swing in the front and rear direction. Nevertheless, the concept of the fabricating method according to the invention may be embodied in knitting the three-dimensional warp knitted fabric such as: in the case in which the front and rear knitting needles 1a, 1b do not constitute the knitting needle rows; or in the case in which the yarn guide bars do not swing and only the front and rear knitting needles swing in the front and rear direction.

[0067] A knitting system or a mechanism therefore may be constructed as follows within compass of the invention. At least one piece or more of the front knitting needle and at least one of the rear knitting needle is able to carry out the knitting. For at least part of the front and rear knitting elements, members including piezoelectric elements or the like are used and controlled for fabricating the three-dimensional warp knitted fabric of the invention.

[0068] As described above, according to the fabricating method and the fabricating apparatus of the invention, it is facilitated to produce the three-dimensional warp knitted fabrics having the varied cross sections. In particular, it is facilitated to produce those having variations in knitting direction in respect of thickness or convexo-concave patterns on the surfaces.

[0069] The three-dimensional warp knitted fabric provided in this way is excellent in ornamental appearance or fanciness as a result of varying in the thickness or convexo-concave patterns on the surfaces. In addition, elasticity, pressure resistance or the other property may be changed locally on the fabric. Thus, invention-wise fabric may be suitably used on interior goods, sheets, cushions and the like.

Claims

1. A method for fabricating a three-dimensional warp knitted fabric having varied cross sections, by use of a double-raschel machine that is comprised of:

front and rear knitting needles (1a, 1b); front and rear knitting-elements supporting bodies (4a, 4b; 5a, 5b) for respectively supporting front and rear knitting elements (1a, 1b; 2a, 2b; 3a, 3b) including the front and rear knitting needles; a mechanism (11a, 11b; 13a, 13b; 15a, 15b; 17a, 17b) for moving the front and rear knitting-elements supporting bodies move in a front-rear direction to come close to or go away from each other; control unit for providing control signals to said mechanism for moving; and a plurality of yarn guide bars (18) for guiding yarns for forming front and rear webs (a1, a2) and connecting yarns; and

the yarns being fed from the yarn guide bars (18) to the front and rear knitting needles (1a, 1b) so that the front and rear webs (a1, a2) are formed and simultaneously connected by the connecting yarns on proceeding of knitting; wherein

on the proceeding of the knitting, positions of and/or an interval between the front and rear knitting needles (1a, 1b) are varied by said mechanism for moving (11a, 11b; 13a, 13b; 15a, 15b; 17a, 17b), so that convexo-concave patterns on surfaces of the front and rear webs and/or a dimension between the front and rear webs are varied in the three-dimensional warp knitted fabric knitted in a single continuous knitting process.

2. A method for fabricating a three-dimensional warp knitted fabric having varied cross sections according to Claim 1, wherein the front knitting needles (1a) along with the front knitting-elements supporting bodies (4a, 5a) are moved as controlled separately, to the rear knitting needles (1b) along with the rear knitting-elements supporting bodies (4b, 5b), so that cross sections are symmetrical or asymmetrical between front and rear surfaces in the three-dimensional knitted fabric.

3. A method for fabricating a three-dimensional warp knitted fabric having varied cross sections according to Claim 1 or 2, said double-raschel machine further comprising a guide-bar swinging element (20) for holding the yarn guide bars (18), wherein, on proceeding of the knitting, the guide-bar swinging element is moved to swing the guide bars in the front-rear direction by guide-bar swinging mechanism (24) connected to a supporting body above a knitting area; and a position of the guide-bar swinging element (20) is controlled such that a position of swinging a yarn guiding needle (18a) at a distal end of the yarn guide bar is disposed substantially at a center between the two contiguous knitting needles, in response to varying in positions of and/or an interval between the front and rear knitting needles (1a, 1b).

4. An apparatus for fabricating a three-dimensional warp knitted fabric having varied cross sections, formed of a double-raschel machine, comprising:

front and rear knitting needles (1a, 1b); front and rear knitting-elements supporting bodies (4a, 4b; 5a, 5b) for respectively supporting front and rear knitting elements (1a, 1b; 2a, 2b; 3a, 3b) including the front and rear knitting needles; a mechanism (11a, 11b; 13a, 13b; 15a, 15b; 17a, 17b) for moving the front and rear knitting-elements supporting bodies move in a front-rear direction to come close to or go away from each other; control unit for providing control signals to said mechanism for moving; and a plurality of yarn guide bars (18) for guiding yarns for forming front and rear webs (a1, a2) and connecting yarns;

wherein said mechanism for moving (11a, 11b; 13a, 13b; 15a, 15b; 17a, 17b) is constructed to be able to vary positions and/or an interval of the front and rear knitting needles (1a, 1b) on receiving of the control signals from the control unit, while proceeding of the knitting.

5. An apparatus for fabricating a three-dimensional warp knitted fabric having varied cross sections according to Claim 4, wherein said mechanism for moving (11a, 11b; 13a, 13b; 15a, 15b; 17a, 17b) is constructed such that the front knitting-elements supporting bodies (4a, 5a) are moved as controlled separately, to the rear knitting-elements supporting bodies (4b, 5b).

6. An apparatus for fabricating a three-dimensional warp knitted fabric having varied cross sections according to Claim 4 or 5, further comprising a guide-swinging element (20) for holding the yarn guide bars (18);
wherein the guide-swinging element (20) imparts swinging movement substantially along a straight line in the front-rear direction relative to the front and rear knitting needles (1a, 1b), to distal-end part of the yarn guide bars (18) to swing the guide bar substantially linearly in the front and rear direction, by guide-bar swinging mechanism (24) interposed between the guide-bar swinging element (20) and a supporting body (23) above a knitting area.

7. A three-dimensional warp knitted fabric having varied cross sections (A) fabricated by the method according to anyone of Claims 1 through 3, wherein convexo-concave patterns on surfaces of the front and rear webs (a1, a2) and/or a dimension between the front and rear webs are varied in the knitting direction.

Drawing