WO2005078178A1

WO2005078178A1 - Method and machine for producing knitwear items and products obtained thereby

Info

Publication number: WO2005078178A1
Application number: PCT/IT2005/000069
Authority: WO
Inventors: Franco Sciacca
Original assignee: Santoni S.P.A.
Priority date: 2004-02-13
Filing date: 2005-02-11
Publication date: 2005-08-25
Also published as: ITCO20040004A1; EP1713966A1; CN1961105A

Abstract

Current knitting production characterized by the combination of a ribbed welt or double bed beside an area of plain knitting or single bed strongly jeopardizes the manufacturing process since it requires a strong take-down, which extends or deforms the stitch and the fabric during the knitting process, also producing an additional, unwanted stress onto the yarn under working. The invention relates to a method and related equipment for producing knitwear items provided with ribbed welt beside plain knitted fabric produced under optimal conditions with knitting sinkers. According to the invention, the quality of plain knitted fabric greatly improves, the single garment or piece of cloth is discharged in an easier way, with various manufacturing, economic, aesthetic and commercial advantages.

Description

METHOD AND MACHINE FOR PRODUCING KNITWEAR ITEMS AND PRODUCTS OBTAINED THEREBY DESCRIPTION Recent years have seen an increase in the demand for knitted items provided with double-bed ribbed welt beside single-bed plain knitted fabric, which is lighter, cheaper and more regular than double-bed or double-jersey fabric. As a rule, said knitted items are manufactured with "double-bed" machines, i.e. ma- chines whose dial and cylinder have special needles equipped with a lateral spring for carrying stitches from one needle bed to the other one. This category generally comprises both rectilinear knitting machines such as Stoll, Shi a . Seiki and Protti and circular knitting machines with medium diameter (14 to 18 inches) such as Santoni SM9, and corresponding machines with large diameter (33 to 42 inches) , which are also equipped with needles in the dial and cylinder such as Variatex 1800 produced by Mecmόr and cor- responding models produced by Jumberca, Mayer, Fuku- har^'a. In recent years manufacturers of these particular double-bed knitting machines have gradually increased their finesses (needles per inch) , but as is known, plain knitted fabric is always produced without using knitting .sinkers, i.e. only with bed needles, therefore said plain knitted fabric is not wholly satisfactory under a technical and textile point of view. The aforesaid circular machines generally operate on ribbed welts by carrying stitches from one needle bed 5 to another one, and also insert the so-called separation yarn between the various pieces of cloth or garments, which terms are known to skilled technicians. Current knitting production characterized by the combination of a ribbed welt beside an area of plain

10 knitting strongly jeopardizes the manufacturing process since it requires systematically a high take-down of the fabric or piece of cloth, which extends or deforms too much the stitch formation; it produces an additional, unwanted stress onto the yarn under work-

15 ing; it makes work resumption more difficult in case of yarn breaking. In the specific case the aforesaid ribbed welt, though being as far as size is concerned only a minimum . portion of the final item, affects technically and negatively the production of the whole

20 item. Moreover, the main portion of the item under ^•working, either piece of cloth or garment, is more and more often carried out with plain knitting, i.e. produced only with cylinder needles without knitting sinkers: a lack that has a high impact onto the gen-

25. ^■ eral quality of the product, which the invention aims at solving. In short, the production of the aforesaid manufactured items does not meet all the requirements of modern textile production, which tends to privilege knitting items provided with the necessary ribbed welt beside an area of a finer and agreeable plain knitted fabric, which suits also mild climates and is lighter and cheaper than double-bed knitted fabric. In particular, at higher gauges the "beauty" or regularity of the knitted fabric produced takes on a textile and commercial importance affecting the fame and fortune of the knitwear factory. This being stated, the present invention aims at reducing or eliminating at least partly the aforesaid technical -manufacturing limitations, with original economic, manufacturing, aesthetic and commercial purposes. As a consequence, a main aim of the invention consists in providing a method and related equipment for producing knitted items obtained with yarns commonly used in the textile industry , therefore natural, synthetic, artificial, elastic, elastomeric and mixed yarns, provided with ribbed welt beside plain knitted fabric (and related knitted structures) produced with the needles of only one needle bed in combination with knitting sinkers. Another main aim consists in providing a method and related equipment for producing knitted items provided with ribbed welt beside plain knitted fabric (and related knitted structures) with cylinder needles only and with knitting sinkers housed therein and operating with basically, horizontal or radial alternated motion. An additional aim consists in providing a method and related equipment for producing knitted items provided with ribbed welt with variously alternated needles beside knitting fabric produced with the needles of only one needle bed operating in combination with suitable knitting sinkers.

Another aim consists in producing the aforesaid knitted items by means of the needles of one needle bed only, with knitting sinkers housed therein and operating with basically vertical and/or elliptical motion. Another aim consists in providing a method and related equipment for producing the aforesaid manufactured items, such as pieces of cloth or garments, without the separation yarn, therefore individually discharged at the end of each production cycle. Further aims de- rive from the description, examples and accompanying drawings, alone or in combination one with the other, beyond final claims. The characteristics of the invention and the resulting advantages will be more evident from the following description of embodiments provided by way- .of example, shown in the accompanying figures,,, in which : Figures 1 to 5 show schematically a pair of needles in different operating steps of a double-bed machine of known type; - Figure 6 shows schematically _. a detail with a pair of needles and a sinker, in a machine according to the invention; Figure 7 shows a sectioned view of a knitted portion made up of an initial double-bed welt and of a plain knitted portion; Figure 8 shows schematically a detail with a needle and a sinker, in a second type of known machine; Figure 9 shows a perspective view of a knitted portion made up of an initial double welt and of a plain knitted portion; Figures 9A, 10A and 10B show textile items produced according to the invention; Figure 10 is a view as in Figure 8 of a knitted portion with an initial double welt and a plain knitted portion.

It should be pointed out that in the present invention the term "textile knitted items" refers to any product to be obtained with a textile knitting method, and thus both fabrics and real finished or semi-finished ite s . Conversely, the invention does not relate to items other than "knitwear items", such as hosiery items, which are produced with small-diameter machines . Medium-diameter machines are machines having a diameter of 9 to 24 inches, whereas large-diameter machines are machines with a diameter above 24 inches. The description will refer to knitting machines in general, in particular to circular machines with me- dium and large nominal diameter of 9 to 42 inches, equipped at least with:

- two needle beds;

- or dial and cylinder rotating against stationary cams or vice versa; - one of the needle beds equipped also with needles for carrying stitches onto the other needle bed;

- one of the needle beds equipped also with knitting sinkers;

- one or more complete working feeds, with yarn strip- ers or moving yarn feeders;

- stitch cams for fabric making, which can be adjusted automatically so as to change their position and knitting density;

- selection for controlling the knitting elements for fabric making., according to a pattern or working pro- grarrt; - a common mechanical or pneumatic latch-opening device for needles; - a pneumatic device for fabric take-down; - or a mechanical device for fabric take-down; - a compressed air device on at least one needle bed. Figures 1 and 2 show schematically an example of the prior art : the common double bed machine is equipped with dial and cylinder and corresponding needles AP, AC (provided also with lateral spring ML) , taking the yarn F so as to produce the rib or ribbed welt knitted fabric MC-BC. It is the traditional ribbed welt produced as a rule at the beginning of a piece of cloth or garment, characterized by variously spaced needles on both needle beds, such as for instance 1:1, 2:1, 2:2, 3:2 and the like. At the end of said ribbed welt produced with the common structure of double-bed knitted fabric, knitted stitches are carried from one needle bed to the other through the special needles pro- vided with a lateral spring referred to with ML in Figures 4-5. After the step in which stitches are carried from the dial to the cylinder, dial needles AP in Fig. 3 are idle, whereas production goes on with plain knitted fabric MR obtained only with cylinder needles AC. Figure 7 shows a sectioned view of a knitted por- tion TM basically made up of the initial double-bed welt MC-BC, interrupted by stitches carried along line LTM, beyond which plain knitted fabric MR begins. According to the invention, the schematic embodiment in Figure 6 shows the needle cylinder modified by the addition of knitting sinkers PM, alternated to cylinder needles. In this specific case, sinkers PM provided with the usual sinking plane PIA take part in the normal fabric-building process together with cylinder needles AC. Said knitting sinkers are well known to skilled technicians and as such do not require any detailed description. Anyway, USA patents no. 1,388,341 - 2,210,796 - 3,149,483 - 3,643,471 - 4,532,781 describe in a full way their main features and show various arrangements on the needle bed and the interaction with needles. The alternated radial sliding of sinkers PM guided by the cams of the sinker-cap or sinker-cover CP as usual (or also with an extended centripetal stroke for dis- charging the knitted fabric at cycle end) enables to control the fabric just formed and push it gradually inside the cylinder. In the various embodiments of the invention, considering technical-textile variables related to the various diameters and gauges of the ma- ^" chines under examination, "both knitting sinkers whose butts follow usual paths made up of stationary cams for current jersey machines, and sinkers whose butts follow paths with moving cams, also spring-loaded. According to the teachings of the invention, knitting sinkers PM, housed inside suitable grooves or notches, can slide freely or be subject to the force of a general take-up and pushing spring towards the cylinder center, especially when smaller diameters are involved. Anyway, the mechanical-textile combination of needles and corresponding knitting sinkers results in various advantages : it improves immediately and clearly the general quality of the knitted fabric, which in this specific case is made under optimal conditions. The need for a forced fabric take-down is strongly reduced; a thicker or narrower stitch and fabric is obtained; cheaper yarns are used, also low- twisting yarns; work can be easily resumed in case any yarn breaks. More to the point, the function of sinkers PM basically modifies also the manufacturing cycle and the general structure of the aforesaid traditional machines . At the end of every working cycle involving a single garment or piece of cloth, the latter is discharged through the centripetal action (extended, if necessary) of sinkers PM, if required strengthened by suitable jets of compressed air suitably placed around the needle cylinder. The expensive fabric take-down device which in particular the aforesaid circular machines are equipped with is too large in its current shape and function; in the framework of the invention, the latter will then become a simple beamer for knitted fabrics if produced continuously. The innovative possibility of discharging from the needles every single garment or piece of cloth at the end of the working cycle also eliminates the need for the so-called separation yarn and related textile operations, thus reducing manufacturing times and costs during knitting and subsequent manufacturing.

The present invention further develops referring explicitly to single-bed knitting machines equipped with hooks in the dial . The example of the prior art shown in Figure 8 relates to a circular "seamless" machine, as described in great detail in US patent 5,222,379, to which reference is made for further details. It is a medium-diameter machine for underwear and knitwear items similar to model SM-8 made by Santoni, which does not require any further explanation since it is well known. Said machines have differentiated diameters whose nominal value is of 9 to 24 inches. The example partially shown in Fig. 8 comprises the cylinder with its needles AC, equipped ^' with usual knitting sinkers PM with sinking plane PIA, alternated to said needles AC. In its coaxial position above, the cylinder rotates integrally with the so-called dial PL, which now houses the hooks U operating in combination with needles AC for building the double welt (or elastic welt) DB-DBE shown in Figs. 9-9A. It is the traditional two-layer belt or elastic welt obtained by discharging the knitted fabric from hooks U to needles AC, ending with usual "bells" or "cups" CU as can be seen on the reverse side of the knitted fabric in Fig. 9. The aforesaid two-layer double welt DB-DBE is present in the pants 1 of Figure 9A and in the current production of underwear and knitwear items obtained with machines having differentiated diameters by the aforesaid company Santoni SM-8 and the like. Said double welt obtained by means of hooks U discharging the knitted fabric has technical, textile, functional and aesthetic disadvantages . The aforesaid "bells" or "cups" CU are generally very delicate and can easily break. Moreover, the latter are very evident and stand out on the knitted fabric, so that as a rule such a manufactured item should not be designed or used on its reverse side. Pattern jacquard with cylinder needles only is necessarily limited since it produces- -floating yarns reducing the general elastic- ity of the belt or since it requires an accurate adjustment of the various yarns (the so-called "plating", a technique known to skilled technicians) . During use the two-layer belt DB-DBE of the pants 1 in Fig. 9A tends to roll up on itself, thus reducing general comfort. Eventually, it should be pointed out that due to aesthetic and commercial reasons plain knitwear items provided with ribbed welt are regarded as most valuable, with an obvious additional value. According to the invention, hooks U of the dial PL in Fig. 8 are therefore replaced by needles AP, thus showing basically the same technical features as the machine already described in Fig. 6, which is by the way provided with at least a complete feed of stitch fabric-building cams. Considering that according to the present invention the textile machine shown schematically in a sectioned view in Fig. 8 is eventually made up of needles AC and sinkers PM on the cylinder, together with needles AP on the dial PL, said operat- ing combination solves most of the problems related to hooks U and thus enables to produce belts and/or ribbed welts for manifold uses and applications as referred to with MC-BC in Figures 10, 10A and 10B. This list is obviously integrated by a large number of other knitwear items such as brassieres, bras, hot pants, dresses, skirts, trousers, sleeves, hoods and others obtained with so-called "seamless" machines, depending on the various gauges and diameters . In order to obtain knitwear items also with the finest ribbed welts, the invention preferably limits to only one needle bed (dial) the use of needles for carrying stitches from one bed to the other, provided with lateral spring (but stitches can be carried also with suitable needles without said spring) . Whereas the ribbed welt MC-BC of Figure 7 represents the lower portion of a generic knitted fabric produced with the aforesaid double-bed machines, the corresponding ribbed welt MC-BC of Figure 10, if turned upside down and produced with suitable yarns, acts as elastic belt for the pants 1 in Fig. 10A or as multifunctional ribbed welt for the manufactured item 1 of Figure 10B produced with single-bed machines with differentiated diameters. The great flexibility of the invention enables to change also to a large extent the shape and functions at least of part of current knitwear production, with the results and effects described above. The present description, necessarily limited, suggests to skilled technicians further innovations, which however fall within the framework of the invention. Figs. 1-2 show ^'■ examples of prior art related to yarn taking and double-bed knitted structure when building a knitted fabric with rib or ribbed welt MC-BC. In Fig. 2 dial needle AP is equipped with lateral- spring ML. Fig. 3 shows dial needles AP, now idle after transferring their stitches are carried onto cylinder needles AC. The textile machine currently produces plain knitted fabric with the needles of one needle bed only or cylinder needles AC. Figure 4 shows a single needle provided with lateral spring ML during the stitch-carrying step, with the corresponding needle of the second bed.

Figure 5 is a front view, of a cylinder needle AC, provided with lateral spring ML, into which dial needle AP is inserted. Fig. 6 shows a sectioned schematic view of the cylinder according to the invention, equipped with knitting sinkers PM sliding alternatively between said needles and controlled by the sinker-cap or sinker-holder CP and related cams ac- cording to traditional textile technology.

Dial needles AP, after working when the initial ribbed welt MC-BC is built, are now excluded from the fabric- building process for plain knitted fabric MR, which is manufactured with cylinder needles AC only together with knitting sinkers PM. Fig.^' 7 shows --a 'sectioned view of the knitted fabric TM made up of the initial ribbed welt MC-BC and of the plain knitted fabric MR lying above. LTM refers to the line for discharging or carrying stitches from dial to cylinder. Fig. 8 basically refers to the aforesaid Santoni SM-8 and similar knitting machines with differentiated diameters, already equipped with knitting sinkers PM but without needles AP with lateral spring, in the dial PL, a term known to skilled technicians, usually pro- vided with hooks U sliding radially.

According to the teachings of the invention, hooks U are therefore replaced by said transfer needles AP, preferably equipped with lateral spring, so as to produce known knitwear items having the valuable ribbed welt for various applications (Fig. 10B) , beyond acting as belt or welt for the pants 1 in Fig. 10A. It should be noted that needles AP with lateral spring (and the like) are much more versatile than said hooks U since they are used for producing both the valuable ribbed welt of Figures 7-10 and the current two-layers welt referred to with DB-DBE in Figures 9 and 9A.

Claims

CLAIMS 1. A method for manufacturing textile knitted items (1) with circular knitting machines with medium or large diameter having two needle beds (CILINDRO, PL) , comprising the step of manufacturing a first double- bed or ribbed welt knitted portion (MC-BC) simultaneously with the needles (AP, AC) of said two needle beds (CILINDRO; PL) , the step of ending said first double-bed or ribbed welt knitted portion (MC-BC) by carrying stitches from the needles (AP) of a first of said needle beds (AC) to a second of said needle beds, characterized in that it further comprises the step of manufacturing a second single-bed knitted portion (MR) with the needles (AC) of said second needle bed and with knitting sinkers (PM) contributing to fabric producing.

2. The method according to claim 1, characterized in that said step of manufacturing said second knitted portion (MR) follows immediately said step of ending said first double-bed knitted portion (MC-BC) .

3. The method according to claims 1 or 2 , characterized in that said second knitted portion (MR) comprises plain knitted fabric.

4. The method according to claims 1, 2 or 3, charac- terized in that said step of manufacturing said second single-bed knitted portion (MR) comprises the step of - producing ribbed stitches for obtaining an at least partially ribbed fabric.

5. The method according to claim 4, characterized in that said plain knitted fabric may contain, also, tuck loops and/or floating yarns or welts .

6. The method according to any of the preceding claims, characterized in that said sinkers (PM) are housed inside said machine and operate between the needles (AC) of said second needle bed (CILINDRO) with horizontal and/όr radial motion.

7. The method according to any of the claims 1 to 5 , characterized in that said sinkers (PM) are housed inside said machine and operate between the needles (AC) of said second needle bed (CILINDRO) with alternated, basically vertical and/or elliptical motion.

8. The method according to any of the claims 1 to 5 , characterized in that said sinkers (PM) are housed inside said machine and operate between the needles (AC) of said second needle bed (CILINDRO) with alternated, diagonal and/or inclined motion with respect to said needles .

9. The method according to any of the preceding claims, characterized in that said first needle bed (PL) is a horizontal needle bed.! or needle dial and said second needle bed (CILINDRO) is a vertical needle bed or needle cylinder.

10. The method according to any of the claims 1 to 8, characterized in that said first and second needle beds (CILINDRO, PL) are vertical needle beds or needle cylinders.

11. The method according to any of the preceding claims, characterized in that it further comprises the step of discharging said textile knitted items indi- vidually at the end of each manufacturing cycle, by automatically discharging the fabric by means of suitable moving elements.

12. The method according to claim 11, characterized in that fabric is discharged by part of said sinkers (PM) .

13. A circular machine with medium or large diameters comprising at least two needle beds (CILINDRO, PL) , at least one of which is also provided with transfer needles for carrying stitches onto the other bed, charac- terized in that on at least one of said needle beds it is provided for sinkers (PM) contributing to fabric building.

14. The machine according to claim 13, characterized in that it further comprises at least a complete work- ing feed, wi.th-yarn stripers or moving yarn feeder; stitch cams for fabric making, which can be adjusted automatically for changing its density; an electronic selection for controlling elements contributing to fabric making according to a pattern or operating pro- gram and a mechanical or pneumatic latch-opening device for needles.

15. The machine according to claims 13 or 14, characterized in that it further comprises a pneumatic or mechanical device for fabric take-down.

16. The machine according to claims 13, 14 or 15, characterized in that it further comprises a compressed air device acting upon at least one needle bed.

17. The machine according to any of the claims 13 to 16, characterized in that said needle beds consist of a dial (PL) of needles and of a cylinder (CILINDRO) of needles rotating against stationary cams or vice versa .

18. The machine according to any of the claims 13 to 17, characterized in that only one of said needle beds is equipped with sinkers (PM) contributing to fabric making .

19. The machine according to any of the claims 13 to 18, characterized in that both said needle beds (PL, CILINDRO) are provided with sinkers (PM) contributing to fabric making.

20. The machine according to any of the claims 13 to

19, characterized in that knitting sinkers (PM) in at least one of said needle beds (PL, CILINDRO) take an active part in the discharge of textile items, discharged individually at production end.

21. The machine according to any of the claims 13 to

20, characterized in that its diameter is of 9 to 24 inches and it is of "seamless" type, in which the dial (PIATTO, PL) houses suitable needles for carrying stitches onto the other needle bed, for manufacturing brassieres, bras, hot pants, dresses, skirts, trousers, sleeves, hoods and the like.

22. Knitwear items obtained by means of circular knitting machines with medium or large diameters, characterized by a first knitted portion (MC-BC) obtained through a first step in which a double-bed or ribbed welt knitted fabric is manufactured simultaneously with the needles (AP, AC) of two needle beds (PL, CILINDRO) , and a second step in which said ribbed welt ends with stitches being carried from needles

(AP) of one needle bed (AC) to another needle bed; and by a second knitted portion (MR) obtained by means of a third step in which the machine produces only sin- gle-bed plain knitted: fabric with needles (AC), of one of said needle beds and with sinkers (PM) contributing to fabric making.

23. The knitwear items according to claim 22, characterized in that tuck loops and/or welts are also made on said second knitted portion (MR) .