Method for the formation of a pocket or heel in a tubular knitted article using reciprocating motion, and article thus produced

Abstract: For the formation of a pocket (such as a heel of a stocking or sock, and/or a toe of such a manufactured article or other) using a circular knitting machine which is capable of operation by means of reciprocating motion and is fed by means of a plurality of drops, that is to say yarn feeds, on every course in one direction - during the reciprocating motion - the part rows of stitches from the yarns of the various drops are formed in a sequence opposite to that in which the part rows are formed during the preceding and following opposite courses; moreover, on each successive reversed course, the yarns of the various drops form rows which are all progressively decreased in the first part of the construction of the pocket and progressively increased in the second part of the construction of the pocket, and with the points of reversal of the rows formed by the various yarns on one side of the pocket arranged according to a sequence opposite to that in which they appear on the opposite side of the pocket.

Description: In the LUCHI patents of 1967/68 (Italy no. 818,060, West Germany no. 1,815,936, U.S.A. no. 3,650,126) and in the subsequent HOFFMANN patents of 1977/78 (Italy no. 1,078,922, West Germany no. 2825864.2, U.S.A. no. 4,188,804), a method has been described for the formation of a pocket in a tubular manufactured article (such as a heel for a woman's stocking or man's sock or in general, and/or the toe of such a manufactured article or other) production being by means of at least two yarn feeds, with reciprocating motion of the needle cylinder, with such an arrangement that a group of rows of stitches according to a given sequence of yarns is followed by a group of rows of stitches according to a reversed sequence of said yarns; each feed supplies the yarn to needles of an arc which is staggered in relation to the arc which has been supplied with yarn from another feed, the arcs being superposed partially in an intermediate zone of greater development of the pocket; the rows of stitches formed during the formation of the pocket are comprised in the arc of needles defined by the two rows of stitches which are most staggered in relation to one another. A number of arcs of needles are all partially staggered in relation to one another in the same direction and are obtained with yarns fed from the same number of staggered feeds. Moreover, the angular development of the pocket is varied by variation of the stitches at the external ends of the rows of stitches which are most staggered in relation to one another. The present invention relates to a method as mentioned above and consequently to a pocket (heel or other) obtained using this method, as an improvement of the Hoffmann patent which is available to the applicant. Aims and advantages of the present invention will be clear from a reading of the following text. Essentially, this method for the formation of a pocket of a manufactured article - such as a heel of a stocking or sock - envisages the use of a circular knitting machine which is capable of operation by means of reciprocating motion and is fed by means of a plurality of yarn drops (feeds), which also participate in the formation of the pocket using reciprocating motion, and envisages that on every course in one direction - during the reciprocating motion - the part rows of stitches from the yarns of the various drops are formed in a sequence opposite to that in which the part rows are formed during the preceding and following opposite courses. According to the invention, on each successive reversed course, the yarns of the various drops form rows which are all progressively decreased in the first part of the construction of the pocket and progressively increased in the second part of the construction of the pocket, the points of reversal of the rows formed by the various yarns on one side of the pocket appearing in a sequence opposite to that in which they appear on the opposite side of the pocket. Other preferred characteristics are indicated in the subclaims at the end of the present description. The present invention also relates to a tubular knitted manufactured article with a pocket - such as a heel in a stocking or sock - which is obtained using reciprocating motion of the cylinder of a circular knitting machine and using a number of yarn drops (feeds), in which pocket the part rows of a group which are formed by successive feeds and then the rows of a similar group of rows formed by the same feeds but in reversed order follow each other. According to the invention, all the part rows are developed from one side to the other of the pocket and are of progressively decreased extension in the first part of the structure of the pocket and of progressively increasing extension in the second part of the structure of the pocket, the points of reversal of the rows formed by the various yarns on one side of the pocket appearing in a sequence opposite to that in which they appear on the opposite side of the pocket. The invention will be understood more clearly by following the description and the attached drawing which shows a non-limiting exemplary embodiment of the invention itself and in which: Fig. 1 shows diagrammatically a sock-type manufactured article with the heel formed according to the invention, in the internal view which shows up the structure of the connections of the part rows; Fig. 2 shows the manufactured article with the heel and the complete rows and part rows for the formation of the heel; Figs 3 and 4 show diagrams to indicate the course of the part rows in a manufactured article produced using a circular machine with four drops, that is to say four feeds. Fig. 5 is similar to Fig. 1, but shows an improv e ment in the formation of the heel; Fig. 6 repeats the diagram in Fig. 1 in order to illustrate the manner of bringing about the improvement; Figs. 7 and 8 show a diagram similar to that in Fig. 3 and a diagram which is similar but modified according to the improvement in Fig. 5. According to what is illustrated in the attached drawing, after the formation of a first portion of manufactured article 101 by means of progressive formation of the rows according to the arrow fL of the knitting work carried out, on reaching the line 103 of the last continuous row, the formation of the heel T is started using reciprocating motion of the needle cylinder. The amplitude of the oscillation of the needle cylinder - for a normal stocking or sock-type manufactured article - extends for approximately one rotation and a half, that is to say for approximately 540°, envisaging an arrangement of feeds as shown in Fig. 4 of four feeds, that is to say drops A1, A2, A3, A4 which are distributed uniformly around the circumference of the work zone of the needles, that is to say of the cylinder C diagrammatically illustrated in said Fig. 4, in which there is developed in a circular sector a given number of part rows of stitches in decreases and in increases respectively, while in the diagram in Fig. 3, the part rows are shown in their development. After completion of the last row RX of the tubular section 101 of the manufactured article before the formation of the heel T, and before restarting the circular motion with the row RY for the formation of the successive section 105 of tubular manufactured article, said heel T is formed using reciprocating motion of the needle cylinder. Using four drops, that is to say using four yarn feeds F1, F2, F3, F4, there are formed on each rotation four continuous circular rows during the formation of the section 101 and of the section 105 of the manufactured article. During the formation of the heel T, the four yarn drops F1, F2, F3, F4 are held in the four feeds, that is to say drops A1, A2, A3, A4, as a result of which, on each oscillation of the needle cylinder, four part rows are formed, with the lengths of these part rows variable in the manner indicated below and in particular visible in Figs 3 and 4. In the formation of the heel, during the first part of such formation, the part rows are reduced, that is to say decreased in extension, as a result of which, on the inside of the heel, there come to be formed small inclined connection sections, indicated by T1, approximately until halfway through the development of the heel; subsequently, in the zone of the augmentations, that is to say increases, there come to be formed similar and opposite connection lines, indicated by T2, which can be barely slightly staggered in relation to the lines T1. In Fig. 2, the courses of the part rows in the heel T are indicated in a rough manner, clearly with a very limited number of part rows even with regard to a structure made using very thick yarns. In Figs 3 and 4, and in particular in Fig. 3, a very simplified diagram is shown, which has a greatly reduced number of decreases and increases, in order to describe the structure of the heel and the method of constructing it. In Fig. 3, AT indicates the arc of needles for the formation of the fabric, and N needles are assumed as maximum limit of the extension of the part rows of stitches. The production of the heel is carried out using a single command of the needles in order to obtain the decreases, that is to say the reductions, and the augmentations, that is to say the increases, of the individual arcs of needles and thus of the individual part rows; this can be achieved very easily using the modern selection systems of electronic type and advantageously with the exclusion of the needles by means of their release at a low level - especially just higher than that of the lower end of the knitting cam - and thus in a state of exclusion; advantageously, means will also be provided for avoiding excessive stress on the stitches held engaged by the needles in the state of exclusion by lowering, in connection with the transit in front of each of the knitting cams, that is to say cams for the lowering of the needles during the formation of the heel. By following in particular the diagram in Fig. 3, it is supposed that the arc AT of active needles for the formation of the heel consists of n needles, which can for example be half the number of needles of the cylinder. The part rows of stitches are indicated by RP1, RP2 - RP35, RP36. Considering the first part row RP1, this is formed by the yarn F1 of the feed or drop A1 which forms stitches along the whole of the arc AT as far as needle number 1. The second yarn F2, which forms a row of stitches immediately after the yarn F1, forms stitches only as far as needle 2; the third yarn F3 forms stitches only as far as needle 3 and the fourth yarn F4 forms stitches only as far as needle 4; the movement of the needle cylinder being reversed, the first part row of stitches RP5 which follows the first four part rows RP1, RP2, RP3 and RP4 is formed by the same yarn F4 which formed the row RP4 and which now forms the row RP5 as far as needle N; the part row RP6, formed by the yarn F3 as far as needle N-1, follows; then the part row RP7 is formed as far as needle N-2 using the yarn F2, and then the part row RP8 using the yarn F1 as far as needle N-3; upon the new reversal of the motion of the needle cylinder, the first part row which is thus formed is the rwo RP9 using the yarn F1 as far as needle 5; directly afterwards, the part row RP10 is formed using the yarn F2 as far as needle 6, and then the part row RP11 using the yarn F3 as far as needle 7 and finally the part row RP12 using the yarn F4 as far as needle 8. Upon the new reversal, the formation is then started of the part row RP13 using the yarn F4 as far as needle N-4; the part row RP14 follows, using the yarn F3 as far as needle N-5; then the part row RP15 is formed by the yarn F2 as far as needle N-6 and finally the part row RP16 is formed using the yarn F1 as far as needle N-7. Upon the new reversal, it is the yarn F1 which forms the part row RP17 as far as needle 9, after which the yarn F2 forms the part row RP18 as far as needle 10 and then the row RP19 is formed by the yarn F3 as far as needle 11 and the row RP20 is formed by the yarn F4 as far as needle 12. Again, upon the subsequent reversal, the part row RP21 is formed by the yarn F4 as far as needle N-8, and this is followed by the part row RP22 using the yarn F3 and as far as needle N-9 and then the part row RP23 using the yarn F2 as far as needle N-10 and the part row RP24 using the yarn F1 as far as needle N-11. At this point it is supposed, in the simplified diagram in Fig. 3, that the decreases, that is to say the reductions in extent of the part arcs, stop and the increase of these part arcs starts, so that the first part of the formation of the heel is completed and the second part of the formation of the heel by means of the increases is thus started. The first part row RP25, which starts the increase in extent of the part rows, is formed by the yarn F1 as far as needle 6; the formation follows of the part row RP26 using the yarn F2 as far as needle 7, then the formation of the row RP27 as far as needle 8 and the formation of the part row RP28 as far as needle 9. The last reversal of the needle cylinder brings about the formation of the part rows RP29, RP30, RP31, RP32 using the yarns F4, F3, F2, F1 respectively, which end respectively at needles N-5, N-6, N-7 and N-8. Upon the subsequent reversal of the motion of the needle cylinder, the formation is then started of the part row RP33 using the yarn F1 as far as needle 2, then the formation of the part row RP34 using the yarn F2 as far as needle 3 and then the formation of the part row RP35 as far as needle 4 using the yarn F3 and the formation of the part row RP36 using the yarn F4 as far as needle 5. The formation of the second part continues using the same principle. The structure of the fabric can be improved in the area of the increases and decreases if provision is made upon inversion of the knitting direction, that at least one needle for each row produces a held or float stitch. It is clear from the description that the arrangement of the part rows affects the whole of the arc of needles AT for the formation of the heel using decreases, that is to say using reductions of the part rows of stitches, which affect all the yarns F1, F2, F3, F4 which were also involved in the formation of the section of manufactured article 101 and which will subsequently form the section of manufactured article 105, in contrast to previous and previously mentioned solutions which envisaged decreases and increases only for one or a maximum of two of the yarns which form part rows, while the part rows formed by the other feed yarns were of constant extent. The arrangement according to the invention makes it possible to obtain a pocket, that is to say a heel, which is better shaped and also more uniform and much more like the conventional heels formed using the reciprocating motion of the needle cylinder and using one single yarn feed. Returning to the diagram in Fig. 1, after the formation of the last complete row RX and that is to say at the front 103 reached by the production according to the arrow fL, the formation is started of the heel using the decreases which progressively give rise to the formation of the connection lines T1, essentially as far as halfway through the formation of the structure of the heel T, then to give rise to the formation of the second part of the heel using the increases in part rows of stitches which give rise to the connection lines T2 until the final front 107 of the heel is reached, after which the circular motion of the needle cylinder is restarted with the formation of the first continuous circular row RY and of the successive rows for the formation of the section 105 of the manufactured article which follows the heel or pocket T. After the formation of the section 105, which forms the foot of the stocking or sock, another pocket can be produced using reciprocating motion and similar to the heel T, which is capable of forming the shaped toe P; this pocket P is then closed at the final edge of the section 105 by means of a darn R formed by means of an auxiliary conventional machine. From the above description, it emerges clearly that, in the zone of the decreases, the reduction in extent of the part rows is very progressive and gradual as, in the zone of the increases, the augmentation of the extent of the part rows is also very gradual. In the diagrams in Figs 3 and 4, it is supposed that the reduction takes place at each needle, but the possibility is not excluded that the reduction can also take place, not at one needle at a time, but every two needles or every three needles or otherwise, according to the number of part rows with which it is envisaged to form the heel or pocket and to the design of the same heel or pocket. From the preceding description, it is clear that during the formation of the second part of the heel, that is to say of the increases, there is a progressive connection of the ends of the increased part rows to the ends of the decreased part arcs in the first part of the formation of the heel. In order to avoid apparent irregularities in the connection, it is advantageous and it emerges from the preceding description that the connections of the ends of the part rows take place with a stagger which can be of one or more needles between the ends of the decreasing rows and those of the increasing rows; for example, the part row RP9 formed using the yarn F1 ends in the region of needle 5, while the corresponding part row RP25, still formed using the yarn F1, ends in the region of needle 6, as a result of which there is a stagger in the connection between ends of part rows of stitches. This gives rise to a slight stagger of the connection lines T1 and T2 and ultimately to a greater uniformity in the structure of the heel. It is further clear that - as already stated - the part rows formed by all the yarns F1, F2, F3, F4 affect the arc AT of the needles intended for the formation of the part rows, and thus there is the greater uniformity already mentioned of the formation of the heel in relation to the formation of heels using the techniques recalled in the introduction. On the basis of what has been described in the preceding case, there are obtained in the heel T the segments indicated by T1 and T2 - due to the marking lines of the decreases and of the increases - which have an approximately herring-bone form. This esthetic motif can be improved by means of what is described below. It is thus possible to vary and to improve the appearance of the marking lines of the decreases and of the increases and in particular in order to render them similar to those produced using conventional machines, in which the working of the pockets of the heel and of the toe is carried out using a single feed; that is to say the formation is possible of a structure of the reel Tx like that indicated by Ty in Fig. 5, with a single line, approximately on the bisector of the angle formed on each side of the heel Tx. Starting from the diagram in Figs 5 and 6, it is a matter of eliminating the hatched fabric zone TE comprised between the two marking lines, that of the decreases T1 and that of the increases T2, in such a manner that the two branches T1 and T2 are superposed, that is to say practically come to coincide. In order to achieve this superposition, it is necessary that, after the reversal of the direction of knitting, the sections of row comprised between the needles in positions 1 to 4 and then 5 to 8 (see Fig. 7) and so on are formed by held or float loops, so as not, in any case, to produce an increase in area; consequently, the formation of fabric in the zone TE in Fig. 6 is eliminated. A recommended but not restrictive plan for the implementation of the invention is that in Fig. 8, in which a small arc represents a held loop (where the needle takes the yarn but does not make a stitch) and a lowered linear section represents a "float" loop, where the needle does not take yarn. According to this plan, the procedure is as follows. The last four rows F1, F2, F3, and F4 of the section 101 of the leg (see Fig. 8) each arrive at their own loop, that is to say at their own end needle 1, 2, 3, 4 of the active arc, producing regular stitches. On reversal, the first of the rows which is carried out is F4; the needle in position 4, which is at the head of this first return row F4, will produce a held loop, while the following needles in position 5, 6 etc. will make regular stitches. In row F3, the needle 3 at the head will make a held loop, while the needle in position 4 will not take the yarn and will make a float loop and subsequently the needles in position 5 and following will make regular stitches. In row F2, the needle 2 at the head will make a held loop, the needle in position 3 will make a float loop, that in position 4 will again make a held loop, and those in position 5 and following will make a regular stitch. Considering finally row F1, the needle 1 at the head will make a held loop, the needle in position 2 will make a float loop, that in position 3 will make a held loop, that in position 4 will make a float loop, and from 5 onwards regular stitches will be made. Using the sequence indicated above, all the reversals with regard to the decreases will be brought about, and the return loops of the four rows 1 to 4 are not detached from the relevant needles and thus do not produce fabric. The above sequence is repeated - with the phase differences due to the reductions in the rows of stitches - upon each reversal of the motion. When the increases are started, the procedure to be followed will be opposite and symmetrical to that described. Therefore, the held and float loops will be made when the reversal end is reached. As can be seen, for example, in the zone indicated by CR in Fig. 8, the last needle of F4, which is the needle in position 9, produces a held loop, in row F3, on arrival, the needle in position 9 makes a float loop and that in position 8 makes a held loop; in row F2, always on arrival, the needle in position 9 produces a held loop, that in position 8 a float loop, that in position 7 a held loop; in row F1, the needle in position 9 produces a float loop, the needle in position 8 produces a held loop, that in position 7 again a float loop and the last in position 6 a held loop. In the return phase, every needle will produce all normal loops. It is intended that the drawing only shows an exemplary embodiment which is given only by way of practical demonstration of the invention, it being possible for this invention to vary in form and arrangement without moreover leaving the scope of the idea which forms the invention itself as defined by the appended claims.

Claims: A method for the formation of a pocket of a manufactured article - such as a heel and/or a toe of a stocking or sock - using a circular knitting machine which is capable of operation by means of reciprocating motion and is fed by means of a plurality of yarn drops (feeds), which also participate in the formation of the pocket using reciprocating motion, and in which, on every course in one direction - during the reciprocating motion - the part rows of stitches from the yarns of the various drops are formed in a sequence opposite to that in which the part rows are formed during the preceding and following opposite courses, characterised in that, on each successive reversed course, the yarns of the various drops form rows which are all progressively decreased in the first part of the construction of the pocket and progressively increased in the second part of the construction of the pocket, so as to form decreases or reductions and increases respectively, the points of reversal of the rows formed by the various yarns on one side of the pocket appearing in a sequence opposite to that in which they appear on the opposite side of the pocket. The method as claimed in claim 1, wherein the part rows of the pocket are reversed in the region of reversal points which are arranged according to a sequence which is essentially uniform for the reductions and the increases carried out on one side of the pocket and according to a similar but reversed sequence which is essentially uniform for the reductions and the increases carried out on the opposite side of the pocket. The method as claimed in claim 1 or 2, wherein the reversal points of the rows of each yarn feed in the second part of the construction of the pocket (increasing part rows) are staggered in relation to those of the first part of the construction of the pocket. The method as claimed in any preceding claim, wherein the decreases and the increases are formed by having recourse to electronic actuators which select needle by needle in relation to each yarn feed drop. The method as claimed in any preceding claim, for producing heels and/or toes of stockings and socks using four drops distributed around the circumference of the working front of the needles, wherein the reciprocating motion is developed through ranges of approximately 540°. A method for formation of a pocket in a manufactured article according to anyone of claims 1 to 5, wherein, in the work zones where the reversal of the direction of motion takes place, the needles are operated so as not to form fabric, bringing about instead held and/or float loops. The method as claimed in claim 6, wherein, during the formation of the decreases - in the first part of the knitting of a heel pocket or similar - on arrival, regular stitches are formed and, on reversal, held and/or float loops, and wherein, during the formation of the increases - in the second part of the knitting of a heel pocket or similar - on arrival, held and/or float loops are formed and, on reversal, regular stitches are formed. The method as claimed in claim 6, wherein, at the end of a part row, one or more held loops are formed, then one or more float loops and so on alternately. The method as claimed in claims 6 and 7 or 8, wherein, towards the end of the pocket, in successive rows, every needle forms alternately held loops and float loops. A tubular knitted manufactured article with a pocket - such as a heel and/or a toe in a stocking or sock - comprising part rows of stitches due to reciprocating motion of the cylinder of a circular knitting machine which uses a number of yarn drops (feeds), characterised in that pocket part rows of a group of rows which are formed by successive feeds and then the rows of a similar group of rows formed by the same feeds but in reversed order follow each other, the points of reversal of the rows formed by the various yarns on one side of the pocket appearing in a sequence opposite to that in which they appear on the opposite side of the pocket, wherein all the part rows are developed from one side to the other of the pocket and are of progressively decreased extension in the first part of the structure of the pocket and of progressively increasing extension in the second part of the structure of the pocket. The manufactured article as claimed in claim 10, wherein the reversal points of the part rows on each side of the pocket are situated according to a sequence which is essentially uniform for the reductions in the rows in the first part of the structure of the pocket, and according to a similar but reversed sequence which is essentially uniform for the increases in the part rows in the second part of the structure of the pocket. A manufactured article as claimed in claim 10 or 11, which comprises, in the end zones of the part rows, held and/or float loops. The manufactured article as claimed in claim 12, wherein held and float loops are alternate and/or in alternate groups.

Inventors: GARIBOLDI FRANCO, GARIBOLDI, FRANCO
Applicants: MERITEX SRL, MERITEX S.R.L.
Application year: 1991
Main classification: D04B9
IPC codes: D04B9, D04B1, D04B15