METHOD AND DEVICE FOR THE INITIAL FORMATION OF A CLOSED TOE ON A CIRCULAR KNITTING MACHINE, ESPECIALLY FOR STOCKINGS AND SOCKS

Abstract: Starting from an initial edge (RA), a pouch (P) is knitted by the needles (1A) of a first arc (A) of approximately a semicircle; after the pouch (P) has been formed, said initial edge (RA) is transferred to the needles (1B) of the opposite arc (B) and picked up by said needles, followed by circular knitting; before the pouch (P) is started, at least one row of loops (RA-RB) is formed on all the needles, so that the initial edge (RA) of the pouch (P) - when transferred - is passed to needles (1B) that are already carrying an initial edge of fabric (RB).

Description: "Method and device for the initial formation of a closed toe on a circular knitting machine, especially for stockings and socks" DESCRIPTION Technical Field The present invention relates to a knitting method and to a circular knitting machine for the production of stockings, socks or the like. In particular, the present invention relates to a method and a device for closing the toe of a knitted article formed on a knitting machine. Background Art In the production of knitted articles of manufacture, such as socks, stockings and the like, one of the major problems lies in the need of closing the toe of the article, i.e. the end portion thereof. This is normally accomplished in a separate stage and on a separate machine, after having completed the tubular article on a circular knitting machine. Several attempts have been made in the art for simplifying and speeding up this particular step of the knitting process. Various methods and devices for closing the toe of a knitted article of manufacture are disclosed for example in IT-A-676,845, IT-A-685,974, IT-A-1,241,770, IT-A-1,205,775, EP-A-0 592 376, DE-A-16 35 992. Object of the Invention Earlier patent application PCT/IT95/00072 (claiming priority from Italian patent application N. FI94A 88 of 17.05.94) and earlier patent application PCT/IT95/00099 (claiming priority from Italian patent application N. FI94A 125 of 16.06.94) belonging to the same applicant, relate to improved methods and devices for the automatic initial formation of a closed toe in a tubular knitted article - such as a stocking or sock or a panty-hose leg- - directly on the circular knitting machine with a needle cylinder on which said article is to be formed. The content of these earlier International patent applications is incorporated in the present specification. In said method, an initial edge of a pouch is formed by the needles of a first arc of approximately a semicircle, and after the pouch has been formed said initial edge is transferred to the needles of the opposite arc and is picked up by said needles. This is followed by circular knitting. The present invention relates to an improvement aimed at obtaining greater regularity in the formation of the join of the initial edge to the needles of said opposite arc. The above mentioned object and other objects and advantages will become clear in the following text. Summary of the Invention In essence, according to the invention, before the initial edge of the pouch is transferred across, at least one row of loops is formed by the needles of the arc opposite the needle arc by which the fabric of the pouch is formed. The initial edge of the pouch - when transferred - is therefore passed to needles that are already carrying an initial edge of fabric. In one possible embodiment, before the pouch is started, at least one circular row of loops is formed on all the needles, so that the initial edge of the pouch - when transferred - is passed to needles that are already carrying an initial edge of fabric. The needles that are to form the circular row of loops or at least the first circular row can be controlled in such a way as to be selected 1:1, and in a second revolution are again selected 1:1 but in reverse. At the time of the transfer, the needles that are to pick up the fabric of the pouch adjacent to the initial edge pass through this fabric when lifted. According to the invention, in order to ensure regularity during the transfer operation, the latches of the needles are lifted towards the needles to a position of at least partial closure, before these needles descend and the otherwise open latches reach the fabric and pass into it, preventing proper closure of the needle as it passes through the fabric and emerges below it. The invention also relates to a device for the automatic initial formation of a closed toe in a tubular knitted article - such as a stocking or a panty-hose leg - directly on the circular knitting machine with a needle cylinder on which said article is formed; devices of this kind comprise a plurality of members for picking up the initial edge of a pouch formed by the needles of one arc of approximately a semicircle and transferring said initial edge to the needles of the other arc of needles opposite, before the circular knitting of the article is started. According to the invention, means are provided for actuating the needles of the arc opposite the arc of needles responsible for forming the pouch, before the members are activated to transfer the initial edge of the pouch of the toe. In practice, the needles of the entire circular bed can be actuated in order to form at least one circumferential row of loops, before the selection means are actuated to form the pouch. Devices of this kind also comprise means for lifting the needles of said arc of needles opposite the arc of needles that has formed the pouch, in such a way that said needles pass through the fabric around the initial edge of the pouch - when transferred - when they rise with their latches open. According to the invention, the device is also provided with means that act on the latches (or equivalent parts) of the abovementioned needles as they descend so as to close them up at least partially towards their respective needles. Said means may consist of a springy metal wire that intercepts the latches of the descending needles, so that the latch is at least partially pivoted towards the hook of its respective needle. The same function could also be carried out by air jet systems. Brief Description of the Drawings A clearer understanding of the invention will be derived from the description and accompanying drawing, the latter showing a practical, non-limiting example of said invention. In the drawing: Fig. 1 shows a plan view of the stage in which a row of loops is formed on all needles before pouch formation is commenced; Figs. 2 and 3 show, in the same way as Fig. 1, the first part of the formation of the pouch and a schematic section on the plane III-III in Fig. 2; Figs. 4 and 5 show, in the same way as Figs. 2 and 3 , the stage in which the initial edge of the pouch is transferred to the arc of needles that are to pick up this edge; Figs. 6 and 7 show, in the same way as Figs. 4 and 5, the stage in which the fabric of the pouch is picked up by the needles of the arc of needles opposite the arc by which the pouch was formed; Fig. 8 shows a perspective view of the position of the members shown on the left-hand side in Fig. 7; Fig. 9 shows a flattened out view, more or less in perspective, from the plane IX-IX of Fig. 8 and Fig. 10 shows in a schematic section similar to Fig. 7 the commencement of the formation of the tubular fabric following formation and closure of the toe. Detailed Description of the Invention As shown in the attached drawing, A denotes one arc of the needle bed in the form of an approximate semicircle, the needles being accommodated in the conventional tricks of the needle cylinder. B denotes a second arc of needles, opposite and complementary to the arc A. 1A denotes the needles of arc A and IB denotes the needles of arc B. When starting to form a tubular article that is intended to have a closed toe, a row of loops RA, RB is characteristically formed on the machine, that is on the needle cylinder around the entire circumference of the needles, before the tubular fabric is formed, as shown in Fig. 1; the row of loops RA, RB may be single or double or a very limited number of rows. The initial half row RB formed by the needles of arc B remains stationary while the fabric of the pouch is being formed by the needles 1A of arc A. The needles forming the first complete row RA-RB will be selected 1:1 on the first revolution, and again 1:1 but inverted on the second revolution. 3 denotes a switching member having the shape of, for example, an arc of approximately 180° and pivoting about the axis X-X which divides the two opposite arcs A and B from each other. Said member 3 carries a plurality of hook parts 5 extending radially and capable of radial movement; these hook parts are for picking up the stitch loops RA formed by the needles of arc A as the initial edge of the fabric P for the toe, which fabric is formed by the needles 1A of said arc A. The hooks 5 can be advanced even before the half row RA is formed. Formation of the fabric P for the toe takes place generally with reciprocating motion of the needle cylinder, by progressive selection of the needles of arc A so as to produce rows of loops that gradually decrease symmetrically relative to the ends of the arc A of needles 1A, and hence increasing symmetrically; the embodiment is known per se for the forming of fabric pouches by reciprocating motion of the needle cylinder. The formation of the fabric P for the toe pouch extends between the needles 1A which are forming it and the initial row RA which is held by the hook parts 5 (see in particular Fig. 3) . When a sufficient amount of fabric P for the toe pouch has been formed - which amount must be greater than the cross-section of the circular bed of the needles of the cylinder -, the member 3 is swung about the axis X-X - by means known per se and with an angular movement as shown by the arrow F3 or in the opposite direction to this arrow - in such a way that the initial edge RA is transferred through the position of Figs. 2 and 3 and through the position of Figs. 4 and 5 to the position shown in Figs. 6 and 7, in which the hook parts 5 swung round with the member 3 about the axis X-X and radially extended, have carried the edge RA beyond and outside of the half arc of needles IB situated around the needle arc B, which have remained stationary during the formation of the fabric P. In this way the fabric P is brought to the position shown in Figs. 6 and 7 and in the diagrams of Figs. 8 and 9. Transfer of the edge RA can be accomplished by any other system of movement. Once the position of Figs. 6, 7, 8 and 9 is arrived at, the needles IB of arc B are lifted and the initial row RB is joined to them as already described; the needles IB pass through the fabric P which has been brought over the arc B of needles IB; the point where the needles IB pass through the fabric P is close to the initial row RA held by the hook parts 5; the needles IB rise with their latches 1BL hanging open away from the hook, as shown in Fig. 8 and on the left of Fig. 9. It is in this situation that work is begun on the tubular fabric T by means of the needles 1A and IB of both arcs A and B. As the needles IB descend they take the yarn F (see Fig. 9) which is also picked up by the needles 1A, in order to commence forming this tubular fabric T. The lowering of the needles IB causes the edge of the fabric P to be joined to the row RB held by the needles IB; the yarn F causes the fabric P to be joined to the initial edge of the tubular fabric T. The small lip defined by the row RA will be on the inside of the tubular fabric T and hence on the inside of the tubular article which is formed in the manner indicated in Fig. 10. At the end of the tubular fabric T, the article is finished in the conventional way and is a practically finished article with a closed toe, and may also optionally include heel pouches formed during the knitting of the fabric T, etc. During the first descent of the needles IB that have passed through the fabric P, the latches IBL of the descending needles IB stay open as shown in Fig. 8 and on the left-hand side in Fig. 9, and would become stuck in the fabric P as the needles IB descend. To avoid this happening, a needle-closing device is adopted, capable of turning the latch IBL from the position of Fig. 8 and of the left-hand side of Fig. 9 to the position illustrated diagrammatically on the right-hand side in Fig. 9 where the latch is raised at least partly or fully placed against the hook of the needle which has taken the yarn F. Such a device may be pneumatic, i.e. designed to emit a blast of air sufficient to throw the blade up as stated. Alternatively the needle-closing device may comprise a more or less springy metal wire 9 whose end portion lies along the path of the needles on the outside of the zone of descent of these needles, as shown in Fig. 9. In this way the wire 9 swings the latches IBL upwards by contact, ensuring that the latter do not become stuck in the fabric P. The presence of the initial row RB in the needles IB ensures a correct and uniform joining of the fabric P adjacent to the initial rows RA, to the tubular fabric T which is to be formed by all the needles and hence also by the needles IB; this regularity is due to the presence of the initial row or rows RB formed by these needles IB. It will be understood that the drawing shows only an illustrative embodiment purely by way of a practical demonstration of the invention, it being possible for said invention to be altered as regards shapes and arrangements without thereby departing from the scope of the concept underlying said invention. The presence of any reference numerals in the accompanying claims is for the purpose of facilitating the reading of the claims with reference to the description and drawing, and does not limit the scope of protection represented by the claims.

Claims: CLAIMS 1. Method for the automatic initial formation of a closed toe (P) in a tubular knitted article - such as a stocking or sock or a panty-hose leg - directly on the circular knitting machine with a needle cylinder, on which said article is to be formed, in which an initial edge (RA) of a pouch (P) is formed by the needles (1A) of one arc (A) of approximately a semicircle, in which after the pouch (P) has been formed said initial edge (RA) is transferred to the needles (IB) of the opposite arc (B) and picked up by said needles (IB) , and in which the circular fabric (T) is then started, which method is characterized in that before the initial edge (RA) of the pouch (P) is transferred across, at least one row of loops (RB) is formed by the needles (IB) of the arc (B) opposite the needle arc (1A) by which the fabric (P) of the pouch is formed; the initial edge (RA) of the pouch (P) - when transferred - being thus passed to needles (IB) that are already carrying an initial edge of fabric. 2. Method according to Claim 1, characterized in that before the pouch is started, at least one circular row of loops (RA, RB) is formed on all the needles, so that the initial edge (RA) of the pouch - when transferred - is passed to needles (IB) that are already carrying an initial edge (RB) of fabric. 3. Method according to Claim 1 or 2, in which, once the fabric of the pouch (P) is transferred, the needles (IB) that are to pick it up pass through it when lifted, which method is characterized in that the latches (IBL) of the needles (IB) are pivoted and closed against the needles, before the open latches can reach the fabric and catch in it as the needles descend. 4. Method according to Claim 1 or 2 or 3, characterized in that the initial edge of fabric (RB) consists of a row of loops on needles selected 1:1, and of a second row formed by needles selected 1:1 in reverse or by all the needles. 5. Device for the automatic initial formation of a closed toe in a tubular knitted article - such as a stocking or a panty-hose leg - directly on the circular knitting machine with a needle cylinder on which said article is formed, comprising a plurality of members (3) for picking up the initial edge (RA) of a pouch (P) formed by the needles (1A) of one arc (A) of approximately a semicircle, which members (3) transfer said initial edge (RA) to the needles (IB) of the other arc (B) of needles opposite, before the circular knitting of the article is started, which device is characterized in that it comprises means for actuating the needles (IB) of the arc (B) opposite the arc (A) of needles (1A) responsible for forming the pouch (P) , before the members (3, 5) are activated to transfer the initial edge (RA) of the pouch of the toe (P) . 6. Device according to Claim 5, characterized in that it comprises means for actuating the needles (1A, IB) of the entire circular bed (A, B) in order to form at least one initial circumferential row (RA, RB) of loops before the selection means are actuated to form the pouch of the toe (P) . 7. Device according to Claim 5 or 6, also comprising means for lifting the needles (IB) of said arc (B) of needles opposite the arc (A) of needles (1A) that has formed the pouch (P) , in such a way that said needles (IB) pass through the fabric around the initial edge (RA) of the pouch when they rise, with their latches (IBL) open, which device is characterized in that it comprises means (9) that act on the latches of the abovementioned needles (IB) as they descend so as to close them against their respective needles. 8. Device according to Claim 7, characterized in that said means consist of a springy metal wire (9) that intercepts the blades of the descending needles. 9. Method and device for the initial formation of a closed toe on a circular knitting machine, especially for stockings and socks; the whole being as described above and as illustrated by way of example in the accompanying drawing.

Inventors: CONTI PAOLO, CONTI, PAOLO
Applicants: CONTI P, GOLDEN LADY SPA, CONTI, PAOLO, GOLDEN LADY S.P.A.
Application year: 1996
Main classification: D04B9
IPC codes: D04B9