DE69001925T2 - Process for the production of semi-finished products on circular knitting machines, in particular for undershirts, shirt pants, underpants and the like. - Google Patents

Description

The present invention relates to a method for producing semi-finished goods using circular knitting machines, in particular for producing undershirts, one-piece bodies, briefs or the like.

As is known from EP-A-0037625, tubular knitwear made with circular knitting machines is used to produce undershirts without side seams. These products have a substantially uniform knit over their entire length, except for any possible decorative patterns. To produce undershirts, they are first cut to the desired length and then four sections are removed from one longitudinal end of the fabric to define the front and back neck openings and the openings for the arms, respectively. When these four sections are removed, four flaps are formed which are then sewn together in pairs to form the shoulders of the undershirt.

A final edge is applied along the cutting lines to remove the four sections and the bottom end of the undershirt is subjected to a hemming step, whereby the attachment of an elastic strip is possible.

In this process, the waste generated by removing the sections corresponding to the neck and arm openings has a significant impact on the manufacturing costs, since the thread used for this type of product is generally of high quality.

In addition, the cutting operations generally require the use of cutting templates to obtain sufficiently accurate results, which consumes a relatively long time. and in turn, production costs will be affected.

Semi-finished products for the manufacture of panties are also known, which are also manufactured using special circular machines that are similar to the circular knitting machines used to make socks and stockings, but have an enlarged needle cylinder.

A first type of product obtained by a process according to US-A-4010627 is manufactured by means of a process which essentially consists in firstly producing an elastic hem and then hemming a section of tubular knitted fabric, using practically all the needles of the needle cylinder. In a subsequent step, an increasing number of needles belonging to two sets of needles are excluded from knitting. These sets of needles are angularly spaced from one another with respect to the axis of the needle cylinder so as to define on the lateral surface of the product two missing sections belonging to leg openings of the panties to be manufactured. The number of needles removed from knitting gradually increases to a maximum value in order to maintain the width of the leg opening and to obtain such a length of the sections between the missing parts that can overlap each other and, by sewing them together, form the gusset of the panties. The thread or threads are cut at the beginning of the set of needles that are not knitting, that is, at the edges of the leg openings, using suitable devices attached to the circular knitting machine used.

The article is finished by attaching an elastic band or an elastic trim to the edges that delimit the leg openings and by sewing together the overlapping ends of the sections of the knitted fabric that lie between the missing parts so as to form, as mentioned, the gusset of the panties. This type of article has the disadvantage that very often, due to the cutting of the thread at the edges of the leg openings, defects or runs can occur which emanate from the edges of the leg openings during the completion of the product, since this is generally pneumatically tensioned, or during ejection from the machine or even during the application of the elastic band, with the result that the article must be rejected. Another type of article obtained by a process according to USA- 4624115 is manufactured by a process in which, instead of cutting the thread at the edges of the leg openings, a complete tubular article is made and two sections are knitted at the leg openings with different stitches compared to those used for the rest of the article, or stitches are knitted along lines corresponding to the boundaries of the leg openings, which enable easy identification of the parts subsequently cut to form the leg openings.

Knitting with different stitches over the entire sections to be removed or limiting them by means of a line knitted with different stitches from the rest of the product allows greater precision and speed for the completion of the product.

This process certainly eliminates the possibility of defects or runs from the finishing work, but has the disadvantage of generating a considerable amount of waste for each product.

The aim of the present invention is to avoid the disadvantages described above by a process for producing a semi-finished product which can be used for the production of undershirts, one-piece bodies, panties or the like, which considerably reduces manufacturing costs, reduces losses due to waste and provides reasonable security against the occurrence of defects or runs in the product during its manufacture.

Within the framework of this aim, it is an object of the invention to provide a method by which the finishing operations can be carried out extremely simply and quickly.

Another object of the invention is to provide a method that enables the production of high-quality goods.

This aim, the above objects and other advantages which will become clear below are achieved by a method for the manufacture of semi-finished goods using circular knitting machines, in particular for the manufacture of undershirts, one-piece bodies, panties or the like, which comprises the manufacture of a knitted body with tubular dimensions and is characterized in that parts of the body to be removed are knitted using more economical yarns than those used to manufacture the remaining parts of the product, and in that the cheaper yarns are processed in an interlocking manner with the yarns of the remaining part of the product near the edges at which the knitting of the parts to be removed begins, the yarns of the remaining part of the product being subsequently cut off, and in that the cheaper yarns are processed in an interlocking manner with the yarns of the remaining part of the product near the edges at which the knitting of the sections to be removed ends, and in that the cheaper yarns are processed in an interlocking manner with the yarns of the remaining part of the product near the edges at which the knitting of the sections to be removed ends, and in that the cheaper yarns are subsequently cut off.

Further characteristics and advantages of the invention will become clear from the description of some preferred, but not exclusive, embodiments of the method according to the invention, which are shown as non-limiting examples in the accompanying drawings. They show:

Figure 1 is a side view of a product for the manufacture of undershirts, which is manufactured in a first embodiment of the method according to the invention

Figure 2 is a view of a product made with a product of the type shown in Figure 1

Figure 3 is a side view of a product for the manufacture of undershirts, which is manufactured according to a second embodiment of the method according to the invention

Figure 4 is a side view of a product for producing a one-piece body, produced in a third embodiment of the method according to the invention

Figure 5 is a side view of a one-piece body made with a product of the type shown in Figure 4

Figure 6 is a side view of a product for manufacturing a pair of panties, which is manufactured in a fourth embodiment of the method according to the invention

Figure 7 is a front view of the product shown in Figure 6

Figure 8 is a view of a pair of panties made with a product of the type shown in Figures 6 and 7

Figure 9 is a view of the enlarged portion of the various articles shown in the preceding figures, in an area of the portion to be removed which is adjacent to the remainder of the article.

With reference to the figures described above, the method according to the invention essentially consists in producing a knitted body with a tubular extension of the required length using a circular knitting machine and in knitting the parts of the product intended to be removed, for example to form the front and rear neck openings and the side openings for the arms in the manufacture of an undershirt, with threads, preferably with a single thread that is less valuable, and therefore more economical, than the thread or threads used to knit the remaining parts of the product. In order to avoid breaks or runs in the product, the thread used to knit the parts to be removed is processed in an interlocking manner with the thread or threads used to knit the remaining part of the product at the edge of said parts to be removed, which is adjacent to the remaining part of the product.

In particular, and with particular reference to Figure 1, the method of manufacturing a product 1 according to the invention may, according to a first embodiment, comprise a first step A during which a first, substantially tubular section of knitted product is manufactured, consisting of four first parts 2 angularly spaced from each other relative to the axis of the product and alternating with four second parts 3 intended for removal. To manufacture the first parts of the knitted product, the needles of the needle cylinder are divided by selection in a known manner into four first sets intended for knitting the first sections 2 and alternate with four wide sets of needles intended for knitting the second sections 3.

In order to produce the second sections 3 with a cheaper thread compared to the threads used for the first sections, an additional thread guide can be provided in a known manner and caused to knit when the needles of the second set reach the feeder of the machine, the thread guide being arranged lower than the thread guides feeding to the needles of the first sets and the needles of the second sets being raised to a level sufficient to interact with the thread fed by the additional thread guides, but not with the thread of the other thread guides. In order to weave the cheaper thread and the thread or threads used for the remaining part of the fabric, the needles of the first sets are made to interact with the thread of the additional thread guides (it is sufficient to activate the additional thread guide a little beforehand), and the first needles of the first sets are also made to interact with the thread of the additional thread guides (by deactivating the additional thread guides with a slight delay). Since the higher quality thread remaining in operative connection with the last needle of the first sets is not processed by the needles of the second sets, it is cut off by a known device provided on the machine at the end of the interlocking processing carried out at the beginning of the formation of the second sections. The lower-quality thread that remains connected to the last needle of the first sets and that has participated in the interlocking processing is not processed by the needles of the first subsequent sets and is therefore cut off in a similar way.

The second sections 3 can be produced with the lower quality thread relative to that used for knitting the remaining part of the fabric if a multiple feed machine is used, for example a quadruple feed machine, in which two machine feeds are provided in which the higher quality thread is fed to the first sets of needles which knit the first sections 2, and two feeds in which the lower quality thread is fed to the second sets of needles which in turn knit the second sections 3, the feed of high quality thread alternating with the feed of low quality thread. In this case, the interlocking processing between the threads near the edges of the second sections 3 can be effected by selecting small groups of needles consisting of last needles of the first sets and first needles of the second sets and of last needles of the second sets and first needles of the first sets in a known manner according to the rotation of the machine needle cylinder. The needles of these groups knit all feeds, but adjacent needles forming the same row of the knitted fabric each knit first on the feeder feeding the high-quality yarn and then on the following feeder feeding low-quality yarn. This order is reversed when knitting a subsequent row.

In this way, an interlocking of the type shown in Figure 9 is achieved; in this figure 31 represents a high-quality yarn, shown in white for simplicity, and 32 is a low-quality yarn, shown in black. It can be seen that knitting stitches with high-quality yarn alternate with knitting stitches with low-quality yarn in the same knitting row in the interlocking region and that a row of stitches knitted by the same needle has the same alternating occurrence of stitches with high-quality yarn and stitches with low-quality yarn. yarn. At the end of knitting the interlocking section, the thread no longer worked by the needles of the first or second sets is cut in the usual way.

During this first step A, it is possible to select the needles, using selection devices usually used in knitting machines for producing socks and stockings, so that the needles of the first sets are multiplied by subtracting them from the needles of the second sets, or vice versa, so as to obtain the desired configuration for the second and first sections. It is also possible, after a preselected number of rows, to divide the needles exclusively into two first sets and two second sets using a known selection device in order to complete the second sections belonging to the openings, while continuing to knit the second sections belonging to the arm openings.

After the first step A, a second step B is carried out; during this step, a second knitting section 4 is knitted in a known manner essentially like the first sections 3.

During the second step B, it is possible to use all the feeders of the machine and to deactivate all the yarn guides intended for feeding the low-value yarn for knitting the second sections from the feeders for which they were intended, in order to use these feeders also for knitting the knitting sections 4, thus achieving a high production speed.

When the fabric has reached the desired length, the knitting is stopped and the fabric is ejected from the machine.

During the first step and a little after the beginning of the second step, stitches 5 are knitted, arranged adjacently in second sections 3. These stitches can be easily distinguished from the others, so that they form a guideline for the finishing. These stitches can be formed by elongated stitches or with an additional thread of a different color.

The semi-finished product can then be subjected to a finishing operation in a simple and rapid manner using a known cutting and hemming type machine, in which finishing edges 6 are applied along the guide lines defined by the stitches 5 along the neck openings and the arm openings. The machine simultaneously removes the second sections 3 together with the sections of the product containing the fabrics made of low-quality and high-quality threads.

The shoulders of the undershirt are then made by sewing the free ends of the first sections 2 together in pairs as shown in Figure 2 and a folded hem 7 is possibly attached to the bottom of the undershirt.

The last operation of hemming the bottom of the undershirt can be omitted if a second embodiment of the method according to the invention is used; this second embodiment allows the manufacture of a product 1a which is already provided with a folded hem at its bottom, as shown in Figure 3.

In detail, in this embodiment, the knitting of the product begins at the lower end with a first step E in which the folded hem 8 is produced in a tubular extension. The hem 8 can be produced in a manner known for the production of upper elastic hems of tights If necessary, the hem 8 can also be produced with an elastic thread to create an elastic folded hem.

After this first step E, a second step F is carried out in which a section of knitted fabric 9 with a tubular extension is produced starting from the elastic hem 8. In a third step G, first sections 10 are produced as a continuation of the sections 9, alternating with second sections 11 to be removed, essentially as already described with reference to the first embodiment, taking into account the fact that in this second embodiment the fabric is produced starting from below.

In this second embodiment, during the formation of the first sections 10 and the knitted section 9, it is also possible to produce stitches 12 in the second sections 11 which are essentially designed like the stitches 5, in order to define a guide line for the subsequent finishing.

With a third embodiment of the method according to the invention, it is also possible to produce a product 13 for manufacturing a one-piece body 14, as shown in Figures 4 and 5.

As is particularly clear from Figure 4, in this third embodiment the method comprises a first step L and a second step M, which are carried out essentially like steps A and B already described with reference to the first embodiment, in order to obtain first sections 15 alternating with removing second sections 16 after a first knitted section, as well as a second knitted section 17 with a tubular extension as a continuation of the first sections 15.

During the formation of the knitting section 17, it is possible to insert one or more elastic threads, preferably in predetermined sections, in order to obtain, for example, an elastic band in the abdominal region. This is possible by feeding an elastic thread to the needles of the machine by means of a suitable thread guide which is activated when necessary.

Subsequently, a third step N is carried out, during which two third sections 19 are produced as a continuation of the second knitted section 17, which alternate with two fourth sections 20 which are intended to be removed in order to form the leg openings of the one-piece body.

The fourth sections 20 are manufactured essentially as described for knitting the second sections 3 in the first embodiment of the method. The fourth sections 20 are preferably provided with a number of stitches that increases starting from the second stitch section 17 by decreasing the stitches of the third sections 19 in order to obtain a suitable shape for the leg openings.

In this way, the fourth sections 20, as well as the second sections 16, are produced by using a thread that is more economical than the thread used for the remaining parts of the product, as already described for the first embodiment of the method. Stitches 21 that are visually distinguishable from the adjacent stitches, as already described as stitches 5, can also be provided adjacent to the fourth sections 20.

When the fabric has reached its desired length, the knitting is finished in the usual way and the fabric is removed from the machine.

In this case too, the finishing can be carried out in a simple and quick manner using a cutting and hemming machine which removes the second sections 16 and the fourth sections 20 and at the same time applies finishing edges 22.

The upper ends of the first sections 15 are sewn together in pairs to obtain shoulder strips of the one-piece body, while buttons and the like are attached to the free ends of the fourth sections 20 for cooperation with each other.

With a fourth embodiment of the method according to the invention, which is shown in particular in Figures 6 to 8, it is possible to obtain a tubular product for the production of briefs.

In detail, the fourth embodiment of the method comprises a first step P in which a folded elastic hem 40 is produced by means of a circular knitting machine in a similar manner to that described with reference to the formation of the hem 8 in the second embodiment. The hem is intended to encircle the hips of the wearer of the briefs. A second step Q is then carried out in which the machine produces, in a known manner, a knitted section 41 with a tubular extension starting from the elastic hem 40. In a third step R, two first sections 42a and 42b are produced as a continuation of the knitted section 41, which are angularly spaced from one another with respect to the axis of the knitted section 41. The sections 42a and 42b alternate with second sections 43a and 43b which are intended for removal and are manufactured substantially like the second sections 3, the second sections 11, the second sections 16 and the fourth sections 20 of the embodiments described above, ie by using a thread which is cheaper than that used for knitting the remaining part of the product.

When the first sections 42a and 42b have reached the desired length, the knitting of the fabric is terminated in a known manner and the fabric is removed from the machine.

In the fourth embodiment, stitches 44 that are visually distinguishable from the adjacent stitches are also knitted adjacent to the edge of the section of the tubular knitted part 41 and the first sections 42a and 42b that are adjacent to the second sections 43a and 43b, as was also the case in the previously described embodiments.

The product thus produced is then ready for the finishing operation which essentially consists in applying a hem 45 near the edge of the first sections 42a and 42b by means of a cutting and hemming machine which simultaneously removes the second sections 43a and 43b. The free ends of the first sections 42a and 42b are placed on top of each other and sewn together to form the gusset of the underpants, as shown in Figure 8.

In practice, it has been shown that the method according to the invention fully achieves the intended aim, since by knitting the sections of the product intended for removal using a cheaper thread than knitting the remaining part of the product and by creating an interlocking area with low-quality and high-quality thread near the edge of the parts to be removed, the economic losses due to waste are reduced and the risk of breakages and runs during knitting is safely excluded.

The invention thus described is susceptible to various modifications and variations, all of which are within the inventive concept. All details can furthermore be replaced by technically equivalent means.

In practice, the materials used, as well as the dimensions, can be selected according to the requirements and the state of the art.

Where reference numerals follow technical features in any claim, the reference numerals have been inserted solely for the purpose of increasing the readability of the claims and therefore have no limiting effect on the elements identified by means of the reference numerals.

Claims (12)

1. Method for producing a semi-finished product by circular knitting on a circular knitting machine, in particular for producing undershirts, one-piece bodies, briefs or the like, by producing a knitted body (1) with a tubular extension, characterized in that portions (3) of the body (1) intended for removal are knitted using threads (32) which are cheaper than the threads (31) used to produce the remaining part (2, 4) of the product (1), and that the cheaper threads (32) are processed in an interlocking manner with the threads (31) of the remaining portion (2, 4) of the product near the edges at which the knitting of the portions to be removed begins, the threads of the remaining portion of the product subsequently being cut off and the inferior threads being cut off near the edge where the knitting of the to be removed, are interwoven with the threads of the remaining part of the product and the inferior threads are then cut off. 2. Method according to claim 1, characterized in that the stitches in the sections to be removed are formed with a single thread. 3. Method according to claim 1, characterized in that stitches (5, 12, 44) that can be visually distinguished from the adjacent stitches are knitted in the adjacent areas to be removed and form a guide line for the finishing of the product. 4. Method according to one or more of the preceding claims, characterized in that it comprises a first step for knitting a first knitted section with tubular extension, which consists of four first sections (2) angularly spaced from one another with respect to the axis of the product and four second sections (3) to be removed, alternating with these, and at least a second step for knitting a second knitted section (B) with tubular extension, which is knitted substantially like the first sections. 5. Method according to claim 4, characterized in that after the second step a third step is carried out in which two sections 19 are knitted as a continuation of the second embroidery section (B, M), the two sections being angularly spaced from one another with respect to the fabric axis and alternating with two fourth sections (20) to be removed in order to produce a one-piece body (14). 6. Method according to one or more of claims 1 to 3, characterized in that it comprises a first step (E) for knitting a folded hem (8) with tubular extension, a second step for knitting a section (F) with tubular extension starting from the folded hem and a third step (G) for knitting four first sections (10) as a continuation of the tubular knitted section, the four knitted sections being angularly spaced from one another with respect to the fabric axis and alternating with four second sections (11) intended for removal. 7. Method according to claim 5, characterized in that the folded seam (8) is produced by adding an elastic thread. 8. Method according to one or more of the preceding claims, characterized in that predetermined sections (18) of the product are produced by adding an elastic thread. 9. Method according to one or more of claims 1 to 3 or 8, characterized in that it consists in the first step (P) for forming a folded elastic hem (40) with tubular extension, a second step (Q) for knitting a section (41) with tubular extension starting from the folded elastic hem and a third step (R) for knitting two first sections (42a, b) as a continuation of the knitted section (41) with tubular extension, the two first sections (42a, b) being angularly spaced from one another with respect to the fabric axis and alternating with two second sections (43a, b) to be removed. 10. Product for the manufacture of undershirts, one-piece bodies, briefs or the like, made of a knitted body (1) with a substantial belly-shaped extension with sections (3) of the body intended for removal, characterized in that the sections (3) are made with a thread (32) which is cheaper than the thread (31) of the remaining part (2, 4) of the product (1), the cheaper thread (32) being processed near the edges of the sections to be removed in an interwoven manner with the thread (31) of the remaining part (2, 4) of the product (1). 11. Article according to claim 10, characterized in that the portions intended for removal comprise stitches made with a single thread. 12. Product according to claim 11, characterized in that in areas of the product adjacent to the areas to be removed, meshes (5, 12, 44) are provided which are optically distinguishable from the adjacent meshes and define a guide line for the finishing of the product.