EP1999306A2

EP1999306A2 - Machine for automatically closing the end edge of a knitted tubular fabric, such as a stocking or a sock

Info

Publication number: EP1999306A2
Application number: EP07736733A
Authority: EP
Inventors: Paolo Conti; Fernando Rossi
Original assignee: NTA SRL
Current assignee: NTA SRL
Priority date: 2006-03-28
Filing date: 2007-03-27
Publication date: 2008-12-10
Also published as: ITFI20060080A1; WO2007110894A3; WO2007110894A2; CN101454492A

Abstract

Machine for closing a tubular article, such as a stocking or a sock, from the inside, said article being started from the hem, sucked upwards by the hollow shaft of the plate on the same machine which has manufactured it.

Description

Machine for automatically closing the end edge of a knitted tubular fabric, such as a stocking or a sock

Technical Field The present invention concerns a machine for the manufacture of a knitted tubular article having a closed end, such as a stocking, a sock or the like.

In particular, the present invention relates to a knitting circular machine with a circular needle bed, or needle cylinder, for manufacturing a tubular article, particularly sports socks, and also for closing one end of said article once weaving is completed.

This invention also concerns a method for directly closing the end of a knitted tubular article on the machine whereby the article has been weaved and a method to modify a traditional knitting machine in order to enable it to close the end of said article directly on the machine thus modified. Background Art

During the manufacture of knitted tubular articles, specifically stockings, socks and the like, said article is woven on a circular knitting machine, which comprises a needle cylinder. The article thus manufactured has an initial edge and an end edge. The end edge must be closed in order to form the toe of said article. To that end, loop-knitting processes were used in the past on the so-called looping machines. Loop-knitting is used for obtaining a practically flawless and particularly smooth closed toe. However, as the experts in the sector know, this process greatly impacts labour, since many people are required in order to insert each single bush or stitch of the row to be knitted on the looping machine's hooks.

Loop knitting is used less and less, owing to the costs and the difficulty in finding labour who are qualified enough to carry out the above operations. This is the reason why new automatic machinery has been designed, which allows the article to be removed from the machine and then transferred to a stitching machine which is specially interfaced with said machine. WO-A-00/01869 describes a device and a closing process whereby the toe of a tubular article is stitched by means of a stitching machine integrated with a knitting machine, specifically placed under the needle cylinder. The tubular article is grabbed by the retaining devices before being completely released by the needles of the knitting machine and is then transferred to the stitching machine placed below by means of a middle-phased overturn system. Once the stitching of the article is complete, it is turned inside out again and removed from the machine. The drawback of this solution lies in the fact that it is complex and requires a substantial modification of the knitting machine in order for the stitching mechanisms to be housed in it. EP-A-1118700 describes a device provided with a system for removing the article from the knitting machine by means of a tubular guide which is joined coaxially to the needle cylinder and to its interior. The article thus removed is then transferred to a system for closing the toe which is external to the knitting machine, positioned on one side for example. The advantage of this system, compared with the preceding one, lies in the fact that it can be realised more easily on traditional knitting machines. However, there are a few limits to this solution, particularly- owing to the axial dimension of the knitting machine which is required to enable the adjustment intervention.

WO-A-98/38367 describes a machine with a circular needle bed and a plate provided with hooks. This machine uses the same needles of the cylinder for closing the toe, without requiring an additional integrated or externally-interfaced stitching machine and thus reducing the machine's complexity. This is achieved thanks to a pushing device which enables the gradual overlapping of the stitches of the two edges to be stitched to a cylinder's needle semicircle. However, the drawback of this solution lies in the fact that it requires a substantial modification of the knitting machine in order for the pushing device to be housed in the cylinder. Furthermore, the pushing devices do not ensure an efficient hold of the fabric to be transferred and the sequential nature of the steps required to bring the stitches together entails an ineffective use of machine time. Disclosure of invention The present invention aims at resolving, at least partially, the aforementioned drawbacks by means of a knitting machine capable of closing the article in a simple and effective way and with a limited number of modifications compared with traditional machines.

The present invention achieves this purpose by means of a circular machine for manufacturing knitted tubular fabrics, such as stockings, socks and the like, which comprises a cylinder provided with a circular needle bed, a plate provided with hooks correspondingly positioned on a circular surface in order to unload/load the fabric's stitches from/to said needles, a device for transferring the stitches released from a first semicircle of needles to the needles of the cylinder's opposing semicircle, wherein said device is provided with a semicircular mobile supporting base or half-ring of hooks capable of removing the fabric stitches from said first semicircle of needles and overlap said stitches to the opposing semicircle by turning said supporting base over said opposing semicircle. Particularly, the device is configured in order to overlap said stitches with the plates' semicircular surface corresponding to said opposing semicircle of needles by turning the supporting base from a position which is essentially coplanar or parallel to the plate's semicircular surface corresponding to the first semicircle of needles, to a position which is essentially coplanar or parallel to the plate's opposite semicircular surface. Thanks to the above-mentioned devices, the stitching of the two edges of tubular fabric is realised by using the same plate and the same cylinder of needles as those used by the machine for knitting the article, without needing to resort to external stitching machines or looping machines and with a limited number of manufacturing stages. No sequential row transfer is required, since all the stitches of one edge are simultaneously transferred onto the stitches of the other edge by overturning the supporting base. Furthermore, since the hooks have a fast and reliable grip, transferring the rows is made particularly effective, thus ensuring a good stitching quality. Conveniently, the machine is provided with recall means for recalling the tubular fabric to the opposite side of the cylinder with respect to the plate. In particular, the plate is hollow and is integrated to a hollow shaft and the fabric recall means are pneumatic means which suck the fabric into the plate' s hollow in the opposite direction with respect to the needle cylinder inside the shaft's hollow. This enables the recalling of the article in an inside-out position and thus its closing without the need to resort to devices for turning inside out said article before stitching. The resulting article is an article started from the hem with the toe internally closed on the same machine as the one which has manufactured it. In order to enable the article to pass through the plate's and the shaft's hollow, such a hollow must be rather large in diameter, particularly in the case of spongy articles such as sports socks. On the other hand, since the diameter of the needle cylinder, and consequently of the plate, is functional to the diameter of the article to be manufactured, for instance it is 4 inches in the case of adult socks, the diameter of the plate's and shaft's hollow cannot be as wide as one wishes. Conveniently, according to the present invention, the diameter of the hollow may be equal to approximately 40-50%, notably around 45%, of the diameter of the needle cylinder. In order to realise said piercing size, the plate's hooks are provided with only one heel and their size is smaller compared with traditional mono-cylindrical machines. In order to ensure an effective operation of said hooks, they are retained in corresponding grooves of the plate by a plaque fastened to said plate. Not only this plaque prevents the hooks from coming out of the guides during normal operation, but it also retains them when, according to one embodiment of the present invention, a portion of the plate rotates so as to overlap with the remaining portion in order to close the toe of the article.

According to another embodiment of the invention, the plate is divided into a first and a second portion, also known as semi-plates, each portion housing a semi- arch of hooks. The first portion can be moved with respect to the second portion, so that it may overturn and overlap with the latter, thus enabling the stitching of the toe. In particular, the first portion is integrated with the supporting base and the hooks of the supporting base overlap, at least partially, with the hooks of the first portion of the plate. In a particularly advaantageous embodiment of the invention, the supporting base overlaps with the first portion of the plate. Practically, it is the plate's function to transfer an edge of knitted fabric on the other edge of knitted fabric so as to enable stitching. To that end, the first portion of the plate is hinged along a diametric axis on the second portion so as to rotate essentially 180° towards the needle cylinder and thus overlap with the second portion, the cylinder and/or the plate being movable lengthwise in order to enable said rotation.

Conveniently, the overturning of said first portion of the plate is caused by the rotation of a hollow toothed shaft inside the plate's hollow shaft, which is engaged with a reel fastened to the first portion of the plate by means of a pin or the like. Alternatively, the overturning of the first portion of the plate may be caused by a lever which is hinged on it and acts as a connecting rod.

According to another embodiment of the invention, the supporting base is integrated with a needle cylinder and is normally positioned on the upper base of the cylinder, or on an essentially parallel plane, facing the plate under the sinkers plane corresponding to the first semicircle of needles. Preferably, the supporting base is mechanically coupled with the cylinder in order to elevate over the sinkers plane and turn over an essentially coplanar surface positioned at the opposing semicircle of needles, so as to enable the closing of the article. The supporting base typically takes the form of a half-ring or sector pivoting along a diametral axis on the base of the cylinder, so as to pivot substantially 180° towards the plate and alternatively position itself on diametrically opposed surfaces at the base of the cylinder, the cylinder and/or the plate being movable lengthwise in order to enable said rotation.

Conveniently, the plate's hollow shaft is coupled with a union, possibly integrated with an anti-twist device, in order to eject the straightened article from the side of the cylinder which is opposite to the plate. In a convenient embodiment of the present invention, the article is properly straightened by means of a suitable device before being ejected. This device comprises a tube-shaped housing for a tong device positioned inside the plate' s hollow shaft or on its union and devices for reversing the suction flow of the article. The end of the tube-shaped housing facing the plate is provided with a shutter with an adjustable gap in order to enable the tong device to project out and thus retain the article when the suction flow is reversed in order to recall the fabric from the side of the cylinder which is opposite to the plate, for instance by means of the standard eject pipe of the traditional machinery, positioned in the lower portion. Practically, the overturned article is retained by the tong device instead of being ejected by the upper suction pipe. By reversing the suction from the upper pipe to the lower pipe, the article is thereby straightened and is thus ready to be ejected through the lower pipe when the tong device releases it.

According to another embodiment, the present invention concerns a method for closing one end of a tubular article by means of a machine comprising, according to the invention, the following steps: a. recall the fabric which is being manufactured upwards through the hollow of the plate and the hollow of the plate's shaft; b. once the article has been manufactured, load the stitches of one of the two halves of the cylinder needles on the hooks of the supporting base in order to close the toe; c. release said stitches from the needles; d. move away lenghthwise the plate's cylinder so as to enable the supporting base to rotate; e. rotate the supporting base in order to transfer the stitches loaded onto the hooks at the second half of the cylinder needles; f . activate said second half of needles so as to create a ladder-proof edge between the stitches thus transferred and the remaining stitches. For instance, the machine may be of a plate type, divided into a first and a second portion, the second portion being movable with respect to the second portion, as illustrated above. In this case, according to step b) of the aforementioned method, it is possible to favourably load the stitches of the second half of needles on the hooks of the second portion of the plate and, according to step e) , the first portion of the plate may be overturned in order to overlap the stitches retained by the hooks of the two portions of the plate. The plate's hooks are partially withdrawn radially before the movable semi-plate starts rotating and are extended again so that the needles may pick up the stitches of the two overlapping edges and carry out the stitching through some rounds of ladder-proof lacing.

If the machine is provided with an undivided plate with a hook supporting base which is constrained to the needle cylinder, according to step e) of the aforementioned method, the stitches of the second half of needles may be loaded on the corresponding hooks of the plate after overturning the supporting base. The hooks of the supporting base are partially withdrawn radially before the supporting base starts rotating and are extended again so that the edges are overlapping and the needles may pick up the knitted fabric of the two overlapping edges and carry out the stitching through some rounds of ladder-proof lacing.

Preferably, according to step a) of the aforementioned method, the tubular fabric being manufactured is pneumatically tensioned in an air suction pipe through the plate and the plate's shaft. To that end, the hollow of the plate and the plate's shaft must be large enough to allow the article to go through, for instance in the order of 45-50% of the cylinder's diameter. Once the lower end has been closed, the fabric is then released by the needles and sucked into the air pipe.

Conveniently this method, according to the present invention, also comprises the following steps: providing a tong device housed in the air suction pipe; - enabling the tong device to project out from its seat so as to hook up the end of the fabric- reversing the suction so as to recall the fabric thus retained downwards; controlling the tong device so as to unhook the end of the fabric- eject the fabric thus turned on the right. According to another embodiment, the present invention concerns a method used for equipping a circular plate machine for the manufacture of knitted tubular fabrics, such as socks and the like, with means for automatically closing the end edge, thereby realising a machine in compliance with the invention. The above method comprises the following steps: replace the plate and the plate's shaft with a plate and a shaft which are hollow enough to allow the article to pass through them, the plate being divided into a first and a second portion, said first portion being movable with respect to said second portion in order to rotate and turn over said second portion; - provide the invention with an air pipe intended for sucking the article through the plate and the plate's shaft; provide a device which controls the turning of said first portion of the plate over said second portion; provide the invention with a control unit which has been set in order to carry out the steps of the method according to the invention.

A few adjustments are sufficient in order to build the machine in compliance with the invention, starting from a traditional type of machine, for instance by- replacing the plate and the plate's shaft with a pair of hollow semi-plates and a hollow shaft, and by- updating the programme which controls the operation of the machine so as to perform the overlapping sequence and the stitching of the edges once manufacturing is complete. Further features and improvements are covered by the sub-claims .

The features of the present invention and the advantages resulting from it will be better emphasised by this detailed description of the enclosed figures. According to the present invention and with reference to the above illustrations, the machine is a traditional tubular knitting machine, typified by a rotating circular crown of needles IA, IB on a supporting cylinder (only the upper portion is shown) which manufacture the knitted tubular article M in the usual way. The plate 3, 4 is positioned coaxially and above the needle cylinder, wherein the hooks 5A, 5B slide radially. The plate is supported by the plate- holder 6 and is set into rotation by the shaft 2. The plate 3, 4 and the shaft 2 are hollow so as to enable the article to pass through as it is sucked upwards by an air suction pipe (not shown in the illustrations) . To the opposite side, inside the needle cylinder, the lower pipe 11 is provided in order to suck and eject the straightened article as shown further below. The lower pipe 11 is made anti-rotating and moves vertically and axially with respect to the cylinder. In the embodiment of the invention shown in figures 1 to 12, the plate is divided into two half- rings 3, 4, also known as semi-plates. As shown in figures 2 and 3, the semi-plate 3 is fastened to the shaft 2 whilst the semi-plate 4 is hinged on its ends, revolving around a diametral axis X-X, on two ends of the shaft 2 by means of a toothed reel 12A fastened to the semi-plate 4 by pin 9 and pivot 12B so as to overturn essentially 180° in order to overlap with the fixed semi-plate 3. The overturning is realised through the rotation of the hollow toothed shaft 18 placed inside the shaft 2 which engages the reel 12A. The shaft 18 is set rotating by the lever 14, actuated by the double-acting piston 15, which drives the bush 13, made anti-rotating by the pin 17, through the pivot 13S inserted in the loop HA.

Alternatively, as shown in fig. 16, the mobile semi-plate 4 may be set rotating by the lever 112 centrally hinged on it. The lever 112 acts as a connecting-rod through the motion applied to its upper end by the bearing 113 which is set rotating by a cam. Fig. 16 depicts, by means of broken lines, the various positions of the lever 112 with respect to the rotating angle applied to the mobile semi-plate 4. This version is particularly favourable compared with the gear version, in that it is simpler and mechanically safer since the working radious is greater. Furthermore, the article does not incur the risk of getting stuck in the gear. The plate's hooks are controlled by cams 21 and 22 which are mounted on the plate-holder 6 and by cam 7 which is housed in the lower pipe 11. The cams 21 and 22 interacts with the heel 220 of hooks 5A, 5B of the plate so as to regulate the radial exit and re-entry, respectively, during the normal operation of the machine. The cam 7 regulates the motion of hooks 5B of semi-plate 4 when overturned in order to carry out the steps required to close the article. The cam 7 may also be housed externally with respect to the cylinder

(please see reference 7A of fig. 4), in particular alongside, so as to be poasitioned with a radial and vertical motion inside said cylinder at the right moment . Fig. 6° depicts, in magnified view, the two overlapping semi-plates after rotation of the first one over the second one. The hooks 5A and 5B have only one heel 220 and are retained by the plaque 20 fastened by means of a screw 120 to the corresponding semi-plate. With reference to figures 5 and 7, the operation of the machine can be summarised in the following manufacturing stages.

A first stage comprises the manufacture of the tubular shape composing the article M by means of a needle crown, whose method of operation is common to all circular knitting machines. The article, while being manufactured, is sucked upwards and turned inside-out in the hollow shaft 2 of the plate. Once the tubular shape has been manufactured to the preset length, the two semi-arches of hooks 5A, 5 B of the plate are controlled so as to orderly take hold of the bushes of the entire circumference of the needles IA, IB. After a few lacing rows have been completed, the needles release the knitted fabric, which is thus hooked to hooks 5A, 5B for the entire circumference. At this stage the hooks are withdrawn internally and the mobile semi-plate 4 rotates 180° downwards while the plate's unit is raised along the vertical axis in order to allow rotation (fig. 5) and then is lowered again once the rotation is complete (fig. 6) . At the end of this stage, the stitches of the edge of toe PA retained on the hooks of the fixed plate 3 overlap with the stitches of the edge of the toe PB retained on the hooks of the tilted mobile semi-plate 4. The two edges PA and PB are subsequently transferred to the semi-arch of needles IA which pierces the fabric, immediately after the rings which are meant for stitching the two edges of the toe PA and PB (fig. 7) . After some lacing rows, the needles IA release the stitches of the finished article M with a closed toe (fig. The transfer of stitches to the hooks 5A and 5B and, after the mobile semi-plate 4 has been tilted, their transfer to the needles IA, is determined by the radial motiom of said hooks controlled by the cams 21 and 22 positioned on the plate-holder 6 and by the cam 7 positioned on the lower pipe 11.

Thanks to the upper suction, the stitching and the subsequent lacing operations are performed inside the article, which is thus ready to be ejected. The ejection may occur by means of the upper pipe 32 connected with the hollow shaft of the plate 2 through the union 23, as shown in fig. 9, possibly fitted with an anti-twist device 24 for manufacturing long stockings ML. In this case the article M is ejected inside-out as soon as the needles IA release the stitches, once the closing of the toe is complete. The ejection may also occur by means of the lower pipe 11 by reverting the suction direction and using a convenient straightening device as the one described as follows . With reference to fig. 10 and 12, the straightening device comprises a pipe 30 coaxially inserted in the hollow shaft 2 of the plate and a tong device 10 housed at the lower end of the pipe 30.

The lower end of the pipe 30 is normally closed by the plug 27 which is conveniently shaped so as not to interfere with the vertical motion of the article during its weaving. When the article is closed and released by the needles IA, the lid, and more generally the end of the pipe 30, interfere with the toe P of the article, retaining the latter by means of the upper suction AS (see fig. 11) .

The tong device 10 comprises a piston 26 which drives the two needles 25 outside the plug 27 against the action applied by the spring 28. The toe P of the article, which is maintained upwards through the suction AS, is thus pierced and then gripped by the two needles 25 which close when the piston 26 ends its stroke through a stopping device positioned inside the pipe 30. By reverting the suction flow from the upper to the lower pipe, the fabric, retained by the toe, is turned inside out and is then finally ejected by the lower pipe when the tong, which is not powered anymore, opens and withdraws into its seat inside the pipe 30 through the recall function exerted by the spring 28 (see fig. 12) .

With reference to figures 13 to 15, according to another embodiment of the invention, an undivided plate 3' ' is provided. The turning inside out and the overlapping of the edges of fabric on a semi-circle of needles is obtained by means of a mobile semi-circular supporting base 4'' of hooks 5B'', which is constrained to the upper portion of the cylinder cooperating with some of the hooks 5A of the plate 3' ' in the same way as illustrated above for the mobile semi-plate 4. Obviously the plate may also be divided in two parts.

The supporting base 4'' is housed in the cylinder and takes the form of a half-ring hinged along a diametral axis of the cylinder 12' which can move lengthwise so as to elevate and rotate 180° through the action of the portion 18''. The hooks 5B'', double- heeled, are moved by the cam 7'', which is also positioned in the cylinder. While the artiche is being manufactured, the supporting base is inactive and is housed under the platens' plane with withdrawn hooks. At the end of the process, the supporting base elevates over the platens' plane so as to load the semi-arch of needles IB on the hooks 5B'' moved by the cam 7'', while the semi-arch of needles IA is attached to the knitted fabric. At this point the hooks 5B'' of the supporting base 4'' withdraw internally and the supporting base 4'' rotates 180° upwards while the plate's unit elevates along the vertical axis so as to enable rotation (fig. 14) and then is lowered again once the rotation is complete (fig. 15) . At the end of this stage, the stitches of the edge of toe PB' ' are retained on the hooks of the supporting base 4'' at the stitches of the edge of the toe PA' ' which are found on the semi-arch of needles IA. The edge PA'' is subsequently transferred from the needles IA to the hooks 5A of the plate 3' ' and then overlaps with the edge PB' ' which is retained by the hooks of the supporting base 4''. According to the subsequent operations, which are the same as illustrated above, the two edges PA' ' and PB' ' are transferred to the semiarch of needles IA which pierce the fabric, straight after the rings which are used to stitch the two edges of the toe PA' ' and PB' ' . After some lacing rows, the needles IA release the stitches of the finished article M with a closed toe. The supporting base 4'' can thus rotate again and reposition itself in its initial seat. The article is ejected and possibly turned inside out in the aforementioned manners, with reference to the first embodiment of the invention.

Naturally, the details of implementation of the present invention are not limited to the above described and illustrated embodiments, but may be widely varied, especially in terms of building methods; however, they never depart from the spirit of the invention above described and claimed below. Brief description of drawings Fig. 1 depicts a lengthwise section of a machine according to a first embodiment of the invention, showing the plate with hollow shaft divided into fixed and mobile semi-plates.

Fig. 2 depicts a chart view of the plate's hollow shaft with the fixed semi-plate and the relevant semi- arch of hooks;

Fig. 3 depicts a chart view of the mobile semi- plate pivoting on two ends of the hollow shaft and the holes where the plaque is fastened. Fig. 4 depicts a chart view of the cams controlling the motion of the hooks.

Fig. 5 depicts the overturning of the mobile semi- plate. Fig. 6 depicts the mobile semi-plate turned over the fixed plate.

Fig. 6A depicts the semi-plates shown in fig. 6 in magnified view. Fig. 7 depicts the stitching of the two edges of knitted fabric once the plate's hooks have withdrawn.

Fig. 8 depicts in cross-section the detachment of the article with a stitched toe.

Fig. 9 depicts the ejection from above of the overturned article with stitched toe.

Fig. 10 depicts the same version of fig. 9 with an anti-twist unit mounted on the upper portion of the hollow pipe.

Fig. 11 depicts in magnified cross-section the tongs of the device intended for straightening the article .

Fig. 12 depicts the device used for straightening the article operating with the toe of the article which is retained by the tong. Fig. 13 depicts a lengthwise section of the machine according to another embodiment of the invention, having an undivided plate and tilting half- ring which is positioned on the needle cylinder.

Fig. 14 depicts the tilting semi-plate shown in fig. 13 while rotating 180°.

Fig. 15 depicts the plate's semiarch of hooks while engaging the knitted edge from the needles in order to overlap it with the other edge.

Fig. 16 depicts another version of the machine shown in fig. 1 wherein a different device for overturning the mobile semi-plate is provided.

Claims

1. Circular machine for the manufacture of knitted tubular fabrics (M) , such as stockings, socks and the like, which comprises a cylinder provided with a circular needle bed (IA, IB), a plate (3, 4, 3'') provided with hooks (5A, 5B) correspondingly positioned on a circular surface in order to anload/load the fabric stitches from/to said needles (IA, IB), a device (4, 4'') for transferring the stitches released by a first semicircle of needles (IB) to the needles of the cylinder's opposing semicircle (IA), characterised in that said device comprises a semicircular mobile supporting base (4, 4'') of hooks (5B, 5B'') which removes the stitches of the fabric (M) from said first semicircle of needles (IB) and overlap said stitches to the opposing semicircle (IA) by turning said supporting base (4, 4'') over said opposing semicircle.

2. Machine, as claimed in claim 1, wherein said device is configured so as to overlap said stitches with the plates' (3) semicircular surface corresponding to said opposing semicircle of needles (IA) by rotation of the supporting base (4, 4'') from a position which is essentially coplanar or parallel to the semicircular surface of the plate (4) corresponding to the first semicircle of needles (IB), to a position which is essentially coplanar or parallel to the opposing semicircular surface of the plate (3).

3. Machine as claimed in claim 1 or 2, wherein means capable of recalling the tubular fabric to the opposite side of the cylinder with respect to the plate are provided.

4. Machine, as claimed in claim 3, wherein the plate (3, 4) is integrated with a shaft (2), such plate (3, 4) and shaft (2) being hollow and the means for recalling the article being air devices which suck the fabric inside the hollow of the plate to the opposite side with respect to the needle cylinder (IA, IB) inside the shaft's hollow, the shaft's and plate's hollow being large enough as to enable the article to pass through.

5. Machine as claimed in claim 3 or 4, wherein the hollow of the plate (3, 4) and/or of the shaft (2) has a diameter essentially equal to 40-50%, particularlu about 45% of the diameter of the needle cylinder (IA, IB) .

6. Machine as claimed in one or more of the above claims, wherein a cam (7, 7A) integrated with the cylinder intended for moving the hooks (5B) of the supporting base (4, 4'') is provided.

7. Machine, as claimed in claim 6, wherein said cam (7, 7A, I¹') interacts with the heel of the semi-arch of hooks (5B) mounted on the tilted supporting base (4, 4''), said cam (7, 7A, 7'') being housed inside the cylinder or on its side in order to position itself radially and axially inside the cylinder when in operation.

8. Machine as claimed in one or more of the above claims, wherein the plate is divided into a first (4) and a second (3) portion, each portion housing a semi- arch of hooks (5B, 5A), said first portion (4) being movable with respect to said second portion (3) in order to overturn and overlap with said second portion (3) , so as to perform the closing of the article (M) .

9. Machine, as claimed in claim 8, wherein said first portion is integrated with said supporting base, the hooks of said supporting base (5B), overlapping, at least partially, with the hooks of said first portion of the plate (4) .

10. Machine as claimed in claim 9, wherein the supporting base overlaps with the first portion of the plate (4) .

11. Machine as claimed in one or more of the above claims from 8 to 10, wherein the first portion of the plate (4) is hinged along a diametral axis on the second portion (3) so as to rotate substantially 180° towards the needle cylinder in order to overlap with said second portion (3), the cylinder and/or the plate being movable lengthwise so as to enable such a rotation.

12. Machine, as claimed in claim 11, wherein the tilting of said first portion of the plate (4) is caused by the rotation of a hollow toothed shaft (18) inside the plate's hollow shaft (2), said toothed shaft (18) engaging with a reel (12A) fastened to the first portion of the plate (4) by means of a pin or the like (9, 12B) .

13. Machine, as claimed in claim 11, wherein the overturning of said first portion of the plate (4) is caused by a lever (112) which is hinged on it and acts as a connecting rod.

14. Machine, as claimed in one or more of the above claims from 1 to 7, wherein the supporting base (4'') is integrated to the needle cylinder (IA, IB) and is normally placed on the upper base of the cylinder, or on a plane essentially parallel to it, facing the plate (3' ' ) below the platens' plane corresponding to the first semicircle of needles (IB).

15. Machine, as claimed in claim 14, wherein the supporting base (4'') is mechanically coupled with the cylinder in order to elevate over the sinkers plane and turn over an essentially coplanar surface positioned at the opposing semicircle of needles (IA), so as to close of the article.

16. Machine, as claimed in claim 14 or 15, wherein the supporting base (4'') takes the form of a half-ring hinged along a diametral axis on the base of the cylinder (12''), so as to rotate essentially 180° towards the plate (3'') and alternatively position itself on diametrically opposed surfaces, essentially parallel to the base of the cylinder, the cylinder and/or the plate being movable lengthwise to enable said rotation.

17. Machine as claimed in one or more of the following claims, wherein the hooks of the plate (5A, 5B) are controlled by a pair of cams (21, 22) which are mounted on a plate-holder (6) positioned on the opposed side with respect to the needle cylinder (IA, IB).

18. Machine as claimed in one or more of the above claims, wherein a union (23, 32) coupled with the plate's hollow shaft (2) for ejecting the straightened article is provided.

19. Machine as claimed in one or more of the above claims, wherein an anti-twist device (24) coupled with the plate's hollow shaft (2) is provided.

20. Machine, as claimed in one or more of the above claims, wherein means (11, H'') for recalling and/or ejecting the tubular fabric through the portion of the cylinder opposed to the plate are provided.

21. Machine as claimed in one or more of the above claims, wherein a device for straightening the article is provided, said device comprising a tube-shaped housing (30) for a tong mechanism (10) positioned inside the hollow shaft (2) of the plate or on the union (32) of said plate and means for reverting the suction flow of the article.

22. Machine as claimed in claim 21, wherein the tube- shaped housing (30) is provided with a shutter (27) with an adjustable gap at the end (P) facing the plate, in order to enable the tong mechanism (10) to project out and thus retain the article when the suction flow is reversed in order to recall the fabric to the side of the cylinder which is opposite to the plate.

23. Method for closing one end of a tubular article with a machine as claimed in one or more of the above claims, characterised in that it comprises the following steps: a. recall the fabric which is being manufactured upwards through the hollow of the plate and the hollow of the plate's shaft; b. once the article has been manufactured and in order to close the toe, load the stitches of one of the two halves of the cylinder needles (IB) on the hooks (5B, 5B'') of the supporting base (4, 4 " ) ; c. release said stitches from the needles (IB); d. move away lengthwise the plate's cylinder so as to enable the rotation of the supporting base (4, 4 " ) ; e. rotate the supporting base (4, 4'') in order to transfer the stitches loaded onto the hooks (5B, 5B' ' ) near the second half of the cylinder needles (IA); f. activate said second half of needles (IA) so as to create a ladder-proof edge between the stitches thus transferred and the remaining stitches.

24. Method as claimed in claim 23, wherein the machine is provided with a plate which is divided into a first (4) and a second (3) portion, said first portion (4) being movable with respect to the second portion (3), the supporting base being composed by said first portion (4), the method being characterised in that, according to step b) , the stitches of the second half of the needles (IA) must be loaded onto the hooks of the second portion (3) of the plate and, according to step e) , the first portion (4) of the plate must be turned over so as to overlap the stitches retained by the hooks of the two portions (3, 4) of the plate.

25. Method as claimed in claim 24, wherein the hooks (5A, 5B) of the plate are at least partially withdrawn radially before the movable semi-plate (4) starts rotating and are extended again so that the needles (IA) may pick up the stitches of the two overlapping edges (PA, PB) and perform the stitching through some rounds of ladder-proof lacing.

26. Method as claimed in claim 23, wherein the machine is provided with an undivided plate (3'') with a hook supporting base (4'') which is constrained to the needle cylinder, said method being characterised in that step e) provides that the stitches of the second half of needles (IA) are loaded onto the corresponding hooks of the plate (5A) after turning over the supporting base (4'').

27. Method as claimed in claim 26, wherein the hooks (5B) of the supporting base (4'') are at least partially withdrawn radially before the supporting base (4'') starts rotating and are extended again so that the edges may be overlapping (PA' ' , PB' ' ) and thus the needles (IA) may pick up the stitches of the two overlapping edges and perform the stitching through some rounds of ladder-proof lacing.

28. Method as claimed in one or more of the above claims from 23 to 27, characterised in that step a) privedes that the tubular fabric being manufactured is pneumatically tensioned in an air-suction pipe through the plate and the plate's shaft, the plate and the plate's shaft being large enough to enable the article to go through.

29. Method as claimed in claim 28, wherein, once the end edge has been closed, the fabric is then released by the needles (IA) and sucked into the air pipe.

30. Method as claimed in claim 29, wherein the further following steps are featured:

- providing a tong device (10) housed in the air suction pipe; enabling the tong device (10) to project out from its seat in order to hook up the end of the fabric- reversing the suction so as to recall the fabric thus retained downwards; controlling the tong device (10) so as to unhook the end of the fabric; - eject the fabric thus turned on the right side.

31. Method used for equipping a plate circular machine for the manufacture of knitted tubular fabrics, such as socks and the like, with means for automatically closing the end edge, comprising the following steps: replace the plate and the plate's shaft with a plate and a shaft which are hollow enough to allow the article to pass through them, the plate being divided into a first (4) and a second portion (3), said first portion being movable with respect to said second portion in order to rotate and turn over said second portion; - provide the invention with an air pipe intended for sucking the article through the plate and the plate's shaft; provide a device which controls the turning of said first portion of the plate over said second portion; provide a control unit which has been programmed in order to carry out the steps of the method as claimed in one or more of the above claims from 23 to 30.