METHOD AND APPARATUS FOR AUTOMATICALLY PRODUCING TUBULAR KNITWEAR ITEMS PROVIDED WITH ONE OR MORE COMPLETE OPENINGS OR BRACES AND PRODUCTS OBTAINED THEREBY

Abstract: The invention relates to tubular knitwear items complete with shoulder straps, braces and various openings for legs or arms manufactured preferably without the usual cutting and sewing operations. Through the appropriate selection of needles, in accordance with the jacquard design and with the operating cycle of the knitting machine, the invention allows the separation and automatic programmed resumption of stitch rows for defined areas or zones, thereby obtaining at least a complete opening (5, 5A) or brace, provided with simple or also double welt, depending on circumstances. Lastly, the invention eliminates nearly completely the usual and costly fabric scrap deriving from the current necessary cutting and sewing operations.

Description: Method and Apparatus for Automatically Producing Tubular Knitwear Items Provided with One or More Complete Openings or Braces and Products Obtained thereby DESCRIPTION Technical Field The present invention relates to a method and an apparatus for automatically producing tubular knitwear items provided with one or more complete openings or braces and products obtained thereby. The recent introduction of "full electronic" circular knitting machines with differentiated diameters has attracted the industry' s interest since the versatility of these machines allows to produce a wide range of semifinished tubular items such as bras, panties, dresses, trousers, skirts, readies, swimsuits, technical items and more . But due tc some inherent technical limitations, among them the lack of shoulder straps, loops and openings for legs and arms, most of the aforementioned knitwear items systematically require laborious and costly additional finishing operations such as cutting or sewing. In practice, in order to obtain loops, shoulder straps and sundry openings, a considerable amount of fabric is scrapped, thereby continuously and permanently affecting production costs. All this stated, the invention intends to reduce to a significant extent or eliminate at least in part some of the aforesaid technical and productive limitations, to manufacture automatically said knitwear items complete with shoulder straps and braces and sundry openings, preferably without fabric scraps, with original economic, technical, aesthetic and commercial purposes. As a consequence, a major aim of the present invention consists of providing a method and the related apparatus for manufacturing tubular knitwear items in general with three-dimensional or shaped effects, provided with at least a complete shoulder strap or loop, preferably manufactured with the continuous motion of the needle cylinder. A further aim consists of providing a method and the related apparatus for manufacturing tubular knitwear items, provided with at least a complete shoulder strap, brace or loop obtained without cutting and sewing operations. An additional aim consists of providing a method and the related apparatus for manufacturing knitwear items such as bras, panties, underwear and outerwear, skirts, trousers and technical items in general, obtained practically without fabric scraps. Another main aim consists of providing a method and the related apparatus for manufacturing tubular knitwear items with complete braces or openings provided with simple or double edges, or with multiple layers, produced both with the aid of the dial, and with needles or sinkers suitable for the purpose, duly selected. Lastly, a further main aim is to provide a method and the related apparatus for manufacturing tubular items made of three-dimensional fabric produced with the fixed and prolonged exclusion of groups of needles also alternating or by groups, with other needles still operating. Disclosure of the Invention The above mentioned aims are substantially achieved by a method for automatically producing tubular knitwear items, in knitting machines provided with at least a needlebed as defined in the claims, in particular comprising the step of producing a first length of tubular knitted fabric having a cylindrical shape and ending with a last stitch course characterized in that it comprises the steps of producing at least a second length of tubular knitted fabric having at least a side opening by excluding a predetermined number of needles of the needlebed from the knit forming process for a predetermined time interval and producing a third length of tubular knitted fabric by automatic and programmed resumption of said predetermined number of needles of the needlebed in the knit forming process, said third length starting with a first stitch course. Advantageously during the step of producing said second length of tubular knitted fabric said predetermined number of needles excluded from the process completely releases the forming knitwear item. Moreover during the step of producing said second length of tubular knitted fabric the needles excluded from the process are adjacent with each other. Additional aims are apparent from the description, embodiments and accompanying drawings, by themselves or in mutual combination, in addition to the final claims. The features of the invention and the advantages which derive from it shall become more readily apparent from the following description of embodiments provided by way of example and can be applied advantageously to most knitwear and hosiery circular machines. Brief Description of the Drawings The description will be made with reference to the accompanying drawings in which: Figure 1 shows a tubular knitted fabric in which a panty to be cut and sewn is defined by dashed lines; Figure 2 shows a tubular knitted fabric in which an undershirt to be cut and sewn is defined by dashed lines; Figures 3 and 5 show the progressive transformation of a knit tube into a bra provided with shoulder straps; Figure 4 is an enlarged view of a particular of fig. 3; Figure 6 shows the application of the invention to obtain a panty; Figures 7 - 8 - 8 a - 9 technically show the steps required for the production of the three-dimensional knit frills Bi; Figure 10 shows the technical diagram for an "embossed" or cellular stitch structure; Figures 11 - 12 -13 show the so-called "tuck stitch" of a needle; Figures 14 - 15 - 16 and 17 show the missing stitch or welt of the needle; Figures 18 through 23 show various embodiments of knitwear items obtained in accordance with the invention; Figures 24-28 show the knit tube shaped with headgear functions; Figure 29 shows a knitted fabric with a knit distorsion or hole; Figure 30 shows a front view of a bra provided with a double edge and with a shoulder strap; Figure 31 shows a side view of another bra provided with a double edge and with a shoulder strap; Figure 32 shows the horizontal or diagonal frills of Figure 31. Description of the Illustrative Embodiments These results are easily achieved according to the invention, and purely with descriptive and non limiting purposes, most of the description concerns an essentially circular machine fitted with at least: a needle bed or cylinder rotating against stationary cams or vice versa; a complete feeding station, provided with one or more yarn feeder; preferably electronic needle selection able to control the elements concurring in the formation of the stitching according to a work cycle and jacquard pattern; pneumatic or mechanical system for drawing the fabric and lastly said circular machine is also equipped with a dial provided with selectable needles or hooks. Currently, many tubular items are completed with laborious cutting operations along pre-defined lines and assembled with delicate and costly sewing operations. For instance, in Figures 1 and 2, the knitted tube 1 provided with double welt 2, as a rule is cut along the dashed lines in order to define the front part A relative to the rear part P, and lastly to sew the resulting edges S together, in correspondence with the extremities 3. These operations inevitably entail considerable quantities of scrap which, although variable according to size and model, often exceed 20% of the initial quantity of fabric: a permanent waste which significantly impacts on the final costs of the products. The invention is initially implemented by setting up or programming a work cycle or jacquard design, i.e. information directed or precluded to the needles and jacks or other elements concurring directly or indirectly in the production of the fabric, by means of a usual graphic station or control or memory device or by means of electromechanical, magnetic, optical apparatuses, and other means suitable for the purpose in any way. In accordance with the invention, the stitched tube of Figure 3 is manufactured starting from the double welt 2A with the aid of the hooks of the dial (not shown) . After a few courses, in correspondence with the symmetric and opposite areas or lines 5 and 5A, according to said work cycle or jacquard the complete release of the loops by a part of the needles takes place. In particular, Figure 4 shows an enlargement of section 6 of the previous figure. Once the manufacture of the double welt 2A is complete, the knit fabric 30, as a rule simple jersey, adjacent to the aforementioned lines 5 and 5A, is preferably modified into operated jersey 7 by appropriately selecting the needles for knitting "non run" of the "unravelling" type, term known to the person versed in the art, characterised by knitting with tucked stitches and welts shown, among others, in Figures 12 - 13 - 14 - 15 of Table 2. In order to increase the resistance to unravelling of the fabric 7, one or more knitted courses immediately preceding the release of the loops along the line 5A, are produced with the additional employment of a particular thermo-adhesive yarn, able to melt gradually at controlled temperatures during the finishing phase. The automatic release of the loops or stitching by the needles along the line or opening 5 (and/or 5A) produces the simple edges or borders 8 and 9, which, under normal conditions, tend to coil onto themselves, like 10 and 11. An aesthetic and functional result that is occasionally appreciable especially in the presence of knitwear items destined for young, practical customers. Conversely, for more demanding customers the invention provides for the aforementioned simple borders or edges 8 and 9 to take on the characteristics of double welts, also elastic, technically similar to the aforementioned edges 2A, and obtainable in various ways: with the usual hooks of the dial selected for the purpose or with a part of the needles of the cylinder, for instance the odd needles AD of Figure 8 which continue to produce stitching whilst the even needles AP hold the respective last loops. Therefore an internal frill or flounce Bi is produced, Fig. 8, or three-dimensional stitching with differentiated growth, widely adjustable in amplitude and height. Lastly, said double edge can be obtained by employing special knitting sinkers, not shown, able to hold the initial stitching rows and release them upon command. Incidentally it should be noted that the so-called "waste", initial or final - term known to the person versed in the art - can be positioned both internally and externally relative to the knitted tube. The release of the stitching by the needles can also be obtained in different ways or times, which may vary according to requirements or technical or textile factors. In a preferred embodiment, if the machine or the work cycle is set to the "zero" position, all feeds are cancelled, the yarn feeders are excluded and all needles in non-working position are engaged to the last loops. Subsequently, only programmed needles are raised completely in a single feed in order to release the related loops or stitches. At this point the knitted tube is engaged only to a part 5 of the needles and the knit-forming process resumes with a simple or double edge, or otherwise, depending on the article being manufactured, after the intervention of the mechanical or pneumatic movable elements serving as tab openers. In accordance with the invention, the total and 10 programmed interruption of the stitch-forming process of a part of the needles of the cylinder, for defined zones or areas of stitching, followed by the automatic and programmed resumption of the stitch-forming process preferably of the same needles and defined stitching 15. areas, produces the total and controlled separation of theoretically consecutive stitching rows characterised in that the former represents the last row of the produced stitching, whilst the latter represents the first stitching row produced after the aforesaid interruption. 20 The tubular knit item 1 of Fig. 5, an undershirt-bra or simple bra, is provided with the edge 2A normally engaged in correspondence with the central part Y but detached or separated, hence open laterally with the creation of the 25 two loops produced automatically, which, folded upwards, according to the arrows FI and ' F2, assume the form and the functions of the shoulder straps 20 - 21. The stitching areas indicated as 11 - 13 - 14 can be produced with different knitted structures, such as the ones shown 30 in Table 2, according to the needs and variables of the moment. In particular, the central area 12 is structurally and functionally connected to the upper part Y of the braces 20 and 21 or to the other adjacent areas, able to support, by themselves or in mutual relationship, in a widely differentiated manner, the breasts. The reference DB indicates the double edge produced after the formation of the brace 20. In another preferred embodiment, Fig. 6, the knitwear tube 1 is provided with the usual double edge 2A and with the edges DB and adjacent 2B. Therebetween are indicated the separation or discharge lines of the stitching 5 and 5A, longer than the similar lines described in Figures 3 - 4- 5 in accordance with the new work cycle or jacquard design. The programmed separation along said lines 5 and 5A produces specifically the two loops 22 and 23 which, folded downwards, are set side by side or overlap with seat functions. The central stitching portion Z, occasionally in excess, is controlled by appropriately selecting the needles, i.e. by reducing stitching production relative to the surrounding areas. Figure 18 shows the bra 1 and the panty 1A manufactured according to the invention. The central part of the aforementioned knitwear items is characterised by vertical areas characterised, in turn, by structures of operated stitching MO, similar to the interlaces indicated in Table 2, i.e. with a plurality or prevalence of tuck stitches, Fig. 10 - 12 and 13, or welts, Figures 14 and 15 together with one or more internal stitching frills or flounces Bi, Figure 8, opportunely located or superposed. The aforementioned vertical operated stitching areas MO are aimed, among other purposes, at the creation of an original aesthetic and functional effect: the central points indicated with the arrows F and FI, located in correspondence with the forward elastic edges 2, are amply displaced relative to the horizontal line represented by the respective rear edges 2B, shown in dashed lines. This displacement is caused by the simultaneous presence of two factors concurring in various ways in the final result: on one hand, the reduced presence of knit rows made scarcely elastic, relative to the surrounding areas; on the other hand, the presence of shoulder straps or loops 20-21 and 22-23 which "tend" respectively to raise, or to lower. An aesthetically pleasing and particularly appreciable result, keeping in mind the natural structural elasticity of the jersey fabric, in particular. The aforementioned knitwear items are therefore strongly characterised by the presence of the upper shoulder straps 20 and 21 and by the lower loops 22 and 23, joined or overlapping with seat functions in this specific case. Incidentally, it should be noted that the items 1 and 1A .can further be enriched with hems or trimmings G produced either automatically through needle selection, for instance the so-called "mouse tooth", term known to the person versed in the art, or by means of the addition of sewn ornamental material, required also if the item 1 is to be completed with the sleeves Ml and M2 sewn in correspondence with the lines S - SI, in Figure 21. The tubular knitwear item 1 of Figure 19 schematically shows a "teddy" or swimsuit or other similar garment provided with two upper braces 20 and 21, produced by the partial separation of the upper edge along the lines 5 and 5A, with the simple upper edges possibly coiled. Two other lower braces or loops 22 and 23 are also produced through the partial separation of the lower edge along the lines 5B and 5C. The item 1 therefore is provided with four braces obtained in correspondence with the two extremities of the knitwear tube, able to conform anatomically to the different parts of the human body. In particular the lower central part K with seat functions is formed by the loops 22 and 23 fully set side by side and overlapping, folded downwards. The invention further develops with the manufacture of the knitwear item 1 shown in Figure 22 initially formed by the upper part A and by the lower part B, both provided with loops or braces 20 - 21 - 22 - 23 and with a double edge 2 produced in correspondence with the median part. Subsequently, a part is inserted into the other one to complete the knitwear item which, in this specific case, is formed by two concentric fabrics, provided with a variable number of shoulder straps, up to four. Among the various embodiments falling within the scope of the present invention is also the knitwear item 1 shown in Figure 23; the interruption and programmed resumption of the knit-forming process in correspondence with the line 5 produces the automatic formation of the single wide brace 20A enhanced with the double edge 2. The programmed repetition of the interruption and the resumption of the knit-forming process produce, on the knitwear tube undergoing work, various openings such as 01 - 02, which can be characterised by simple edges BS, or by double edges DB in correspondence with the openings 03 and 04. With reference to the knitwear item 1 variously illustrated in Figures 24 through 28, the invention is realised in accordance with the method schematically shown in Figures 7 - 8 and 9. Contrary to the norm, a part - which may even be substantial - of impulses or commands usually directed to the needles, is not sent to a part thereof, according to a defined scheme or program, conforming to the original design. This causes the exclusion from the knit-forming process of the needles lacking inputs or commands; this exclusion, total and for defined zones, produces the floating threads FF instead of the stitching M, Fig. 7. Consequently, the fabric produced or, better yet, the knit tube, undergoes a structural deformation caused by the differentiated growth of the stitching in its entirety, suitable for predetermining three-dimensional shaping of the fabric able to conform to the different anatomical parts. The aforementioned floating threads FF, Fig. 7, can be further manipulated with the use of some needles A, shown working in Fig. 8, duly spaced in the aforesaid total exclusion zone, with the dual purpose of reducing the length of the floating threads and create, if the case warrants it, pleasant knit interlaces. Hence the invention is fully realised by further manipulating the aforesaid floating threads FF and transforming them into knit fabric produced only with a part of the needles present in the involved areas or zones. For instance, only even needles or alternating pairs of needles will be excluded; i.e. in groups of three operating needles followed by one or more excluded needles, and so on. The simultaneous presence of working needles, alternating with excluded needles, Fig. 8, for defined areas and for a time which may even be relatively long, Fig. 9 (corresponding to a high number of stitch knitted courses) , is the sufficient and necessary condition for the manufacture of an original stitched fabric, formed by the working needles and related loops AD but interrupted and still interlaced with the excluded needles and loops AP, in order to produce a closed knit frill, with two layers or fabrics Bi, Fig. 8, inside the usual stitched tube. This growth of supplementary stitching or frill Bi is characterised on the front of the stitch by a perfect suture caused by the elongation of the loops or stitches of the needles AP not working and hence excluded from the manufacture of the aforesaid frill, which is repeatable and/or variable in height and width. Such frills Bi are particularly attractive if arranged in small repeated diagonals, so as to accentuate anatomic support and the "padding" effect, being three-dimensional (Figs. 31 and 32) . The method just described is further shown in Figures 24 and 25 of Table 4, which illustrate an additional embodiment of the invention concerning the anatomical conformation of the knitwear item 1. In particular, Figure 24 shows a knit tube 1, viewed laterally, having the usual elastic edge 2. In this specific case the aforementioned frills Bi formed by two layers or fabrics, are inside the knit tube 1, only on the lower part. With the aid of individual computer- controlled stitch-forming cams (not shown) , the density of the stitching 13 can be widened only in correspondence with the designated area 11 in order to accentuate the shaping or anatomical conformation effect, necessary in the case at hand. The lower part of the knit tube is in any case subject to the reduce density of stitching 12 or operated stitching MO, together with the presence of knit frills Bi produced with the previously described technique illustrated in Figure 7 - 8 - 9. Figure 25 shows the final effect, i.e the knit tube 1 duly shaped according to the arrow F; the internal knit frills Bi produced in correspondence with the neck effectively contribute to the final effect. Said knit item 1 can be produced indifferently as a mere head garment or as the initial or final part of a track suit, dress or other technical item. Figures 26 and 27 differ from the previous ones in some variations concerning the presence of a simple edge 32, with wound external waste 31 or simple wound edge 33 and 34. Fig. 28 shows the item 1 characterised in that at the start of the manufacture of the knit tube 35, a predetermined number of needles suitably positioned or spaced, also in groups, are excluded from the productive process for a certain time. This set-up produces a generally more transparent stitching in the sense of the columns or ribs, schematically represented by the dark horizontal lines. The start of work by said needles produces, among other effects, also knit distortions or the holes 36, Fig. 29, which, suitably positioned, also serve an aesthetic function. The ample flexibility of the ' invention allows to modify even substantially the shape and the functions of at least a part of the current knitwear and hosiery production with the described effects and results. The present description, necessarily limited, provides the person versed in the art with broad margins for innovation, all falling within the scope and aims of the invention.

Claims: CLAIMS 1. Method for automatically producing tubular knitwear items, in knitting machines provided with at least a needlebed or cylinder, comprising the step of: producing a first length of tubular knitted fabric having a cylindrical shape and ending with a last stitch course characterized in that it comprises the steps of: producing at least a second length of tubular knitted fabric having at least a side opening by excluding a predetermined number of needles of the needlebed from the knit forming process for a predetermined time interval and producing a third length of tubular knitted fabric by automatic and programmed resumption of said predetermined number of needles of the needlebed in the knit forming process, said third length starting with a first stitch course. 2. Method according to claim 1 wherein during the step of producing said second length of tubular knitted fabric said predetermined number of needles excluded from the process completely releases the forming knitwear item. 3. Method according to claims 1 or 2 wherein during the step of producing said second length of tubular knitted fabric the needles excluded from the process are adjacent with each other. 4. Method according to claims 1 or 2 wherein during the step of producing said second length of tubular knitted fabric the needles excluded from the process are chosen according to a predetermined sequence along the needlebed. 5. Method as claimed in claim 1 for manufacturing tubular knitwear items with three-dimensional and shaped effects, provided with at least a complete shoulder strap or loop, produced automatically also with the continuous motion of the cylinder. 6. Method as claimed in claim 5 for manufacturing tubular knitwear items in general, provided with at least a shoulder strap, brace or opening and obtained without cutting and sewing operations. 7. Method as claimed in claim 6 for manufacturing knitwear items in general provided with at least a complete shoulder strap or loop, provided with simple or double edge, obtained essentially without fabric scrap. 8. Method as claimed in claim 7 for manufacturing knitwear items such as bras and panties, characterised in that in the central and preferably frontal zone, (FI - F2), the tensions of the operated stitching (MO) concur in lifting or lowering the final position of the front elastic edge (2) relative to the part of the same back edge (2B) . 9. Method as claimed in claim 8 for manufacturing knitwear items wherein two concentric fabrics are provided also with shoulder straps or loops. 10. Method as claimed in claim 9 for manufacturing knitwear items provided with shoulder straps or loops, suitable for being completed with additional sleeves, sewn subsequently without fabric scrap. 11. Method as claimed in claim 1 characterised by the presence of an internal frill made of multi-layer fabric produced by the preferably fixed selection only for some needles such as the odd ones, or needles in alternating pairs; i.e. in groups of three working needles followed by one or more excluded needles, and hence by the simultaneous presence and textile function of working needles alternating with still excluded needles, for defined zones and for a time which may even be relatively long, in order to produce at least a knit frill with two layers or fabrics inside the usual knit tube. 12. Method as claimed in claims 1-7, characterized by the presence of an internal frill of multi-layer fabric, repeatable and variable both in height and width. 13. A circular machine for manufacturing knitwear items in general, also technical ones, according to the method of claim 1, characterized by comprising at least: a needle bed and/or cylinder rotating against stationary cams and/or vice versa, provided with needles and/or other movable parts concurring in knit formation; a complete feeding station provided with one or more yarn feeders; needle selection system, preferably electronic or electromechanical; a dial with hooks complete with thread cutting device or other upper needle bed as well as a system for drawing the fabric or sock. 14. A circular machine as claimed in claim 13 for manufacturing knitwear items in general, with three- dimensional or shaped effects and provided with at least a complete shoulder strap or loop, produced automatically also with the continuous motion of the needle cylinder, i.e. provided with at least a shoulder strap, brace or opening (s) obtained without cutting or sewing operations. 15. Knitwear items obtainable with the method according to any of the claims 1-12. 16. Knitwear items, underwear and outwear in particular, according to claim 15, characterised by tuck stitches, welts, embossed, cellular. 17. Knitwear items as claimed in claim 15 manufactured with interlaces characterised by the presence of horizontal frills (Bi) and also diagonal frills (Bi) . 18. Apparatus for preparing diagrams or work cycles comprising the selective transmission of information to the needles according to the method of claim 1.

Inventors: SCIACCA FRANCO, SCIACCA, FRANCO
Applicants: SCIACCA FRANCO, SCIACCA, FRANCO
Application year: 2000
Main classification: D04B1
IPC codes: D04B1