EP1828459B1

EP1828459B1 - Method for joining portions of knitting produced by at least two mutually spaced groups of needles of a bed, in circular hosiery knitting machines with two beds or the like

Info

Publication number: EP1828459B1
Application number: EP05850255A
Authority: EP
Inventors: Tiberio Lonati; Fausto Lonati; Ettore Lonati
Original assignee: Santoni SpA
Current assignee: Santoni SpA
Priority date: 2004-12-23
Filing date: 2005-12-12
Publication date: 2009-07-29
Anticipated expiration: 2025-12-12
Also published as: DE602005015755D1; CN101080521A; WO2006066751A1; TW200636107A; ITMI20042496A1; EP1828459A1; CN101080521B

Description

Technical Field

The present invention relates to a method for joining portions of knitting produced by at least two mutually spaced groups of needles of a bed, in circular hosiery knitting machines with two beds or the like, in which the two beds are coaxial and face each other. The method according to the invention can be used in particular to join portions of knitting produced by at least two groups of needles located in two sectors of a same bed, constituted for example by the needle cylinder of a cylinder-and-dial machine, which are mutually angularly spaced around the axis of the bed, on the same machine used to produce them.

Background Art

Circular hosiery knitting machines are known which have two coaxial and mutually facing beds and are constituted for example by a needle cylinder, which has a vertical axis, and by a dial, which is arranged above and coaxially with respect to the needle cylinder.
A plurality of axial slots are provided on the lateral surface of the needle cylinder, and each slot accommodates a needle which can be actuated with a reciprocating motion along the corresponding axial groove in order to produce knitting.
In the dial of these machines there are a plurality of radial slots, each of which accommodates at least one engagement element, which can be constituted by a hook or by a pusher or by a needle, which can move on command along the corresponding radial slot in order to pass from an extracted position, in which it protrudes from the peripheral profile of the dial, to a retracted position, in which it is recessed within the dial in order to avoid interfering with the needles of the needle cylinder.
In the extracted position, the engagement elements can interact with at least one needle of the needle cylinder in order to engage a loop of knitting or more generally a portion of a row of knitting produced by the needles of the needle cylinder or in order to release a loop of knitting or a portion of a row of knitting engaged previously to a needle of the needle cylinder.
In the retracted position, the engagement elements can retain the loop of knitting or portion of row engaged previously without interfering with the needles of the needle cylinder.
Depending on the type of engagement element used, the engagement elements can pick up loops of knitting, in the strict sense of the term, from the needles that have produced them or can retain portions of loop linking yam during the formation of a row of knitting by the needles of the needle cylinder and then release to the needles of the needle cylinder the loops of knitting previously picked up or the portions of loop linking yam previously retained. For the sake of simplicity in presentation, the expression "loop of knitting" is understood hereinafter to designate a portion of a row of knitting which can be constituted by a loop of knitting in the strict sense of the term or by a portion of loop linking yam.
In some machines, each engagement element is constituted by two or more elements arranged side-by-side, which are generally arranged in a same radial slot of the dial and cooperate with each other and with the needles of the needle cylinder in order to pick up loops of knitting from the needles of the needle cylinder or release to the needles of the needle cylinder loops of knitting previously picked up by other needles of the needle cylinder or retained during the formation of a row of knitting on the part of the needles of the needle cylinder.
If the engagement elements arranged in the dial are constituted by needles, said needles, in addition to being usable to engage or pick up loops of knitting produced by the needles of the needle cylinder, can also be used to produce knitting.
In the field of the production of items of clothing known as "seamless", i.e., items of clothing which have a tubular structure without seams at their lateral regions, the need is felt to be able to join portions of knitting, produced by groups of needles which are arranged in the needle cylinder and are angularly spaced from each other around the axis of the needle cylinder, so as to avoid the need to subsequently rework the item of clothing in order to produce the seam for joining said portions of knitting.
A need of this kind occurs for example for the shoulder straps of vests, bras, body suits or for the crotch of underpants.

Disclosure of the Invention

The aim of the present invention is to meet this requirement by providing a method which allows to perform, directly on the machine used to produce an article, the joining of portions of knitting of the article produced by at least two groups of needles, located in two sectors of a bed which are mutually angularly spaced around the axis of the bed, in circular hosiery knitting machines with two beds or the like.
Within this aim, an object of the invention is to provide a method which, by avoiding the sewing operation in order to join portions of knitting, allows to reduce the production costs of these items of clothing.
Another object of the invention is to provide a method which, by avoiding the use of stitched seams to join portions of items of clothing, allows to produce items of clothing which are more comfortable.
This aim and these and other objects, which will become better apparent hereinafter, are achieved by a method for joining portions of knitting produced by at least two mutually spaced groups of needles of a bed in circular hosiery knitting machines with two beds or the like, which comprise two coaxial and mutually facing beds, respectively a first bed provided with needles which can be actuated in order to produce knitting and a second bed provided with engagement elements which can be actuated in order to retain or pick up loops of knitting formed by the needles of the first bed or to release loops of knitting previously retained or picked up to the needles of the first bed, characterized in that it comprises:

a step for forming, with a first group of needles arranged in a first sector of the first bed, at least one first portion of knitting composed of a plurality of rows of knitting;
a step for forming, with a second group of needles arranged in a second sector of the first bed which is angularly spaced from said first sector of the first bed around the axis of the first bed, at least one second portion of knitting composed of a plurality of rows of knitting;
a first step for transferring at least one row of knitting of the second portion of knitting and at least part of the needles of a group of joining needles arranged in a third sector of the first bed which is interposed between said first sector and said second sector of the first bed, said first transfer step being performed by means of said engagement elements of the second bed and by means of an angular offset of the second bed with respect to the first bed about its axis;
a second step for transferring at least one row of knitting of the first portion of knitting to at least part of the needles of said group of joining needles, said second transfer step being performed by means of said engagement elements of the second bed and by means of an angular offset of the second bed with respect to the first bed about its axis;
a step for forming at least one row of joining knitting by means of the needles of said group of joining needles, which are engaged with said first portion of knitting and with said second portion of knitting which joins said first portion of knitting to said second portion of knitting;
a step for disengaging said group of joining needles from said portions of knitting.

The method according to the invention is meant to be performed preferably with a circular hosiery knitting machine of the type which comprises a needle cylinder having a vertical axis and a dial which is arranged above and coaxially with respect to the needle cylinder and is provided with engagement elements which can be actuated in order to retain or pick up loops of knitting formed by the needles of the needle cylinder. If said engagement elements are constituted by hooks or pushers, i.e., elements which are not capable of forming knitting, the expression "first bed" is to be referred exclusively to the needle cylinder and the expression "second bed" is to be referred exclusively to the dial. If instead the engagement elements of the dial are constituted by needles, i.e., elements which can be actuated in order to form knitting, the expression "first bed" can be referred again to the needle cylinder and the expression "second bed" can be referred again to the dial or, equally, the expression "first bed" can be referred to the dial and the expression "second bed" can be referred to the needle cylinder. In this last case, the needles of the needle cylinder constitute the engagement elements of the second bed.
Without altering what has been specified above, for the sake of simplicity in description and greater clarity, the method according to the invention is described hereinafter by assuming that the "first bed" is the needle cylinder and the "second bed" is the dial of a circular hosiery knitting machine of the type with a needle cylinder and a dial.

Brief Description of the Drawings

Further characteristics and advantages of the invention will become better apparent from the description of a preferred but not exclusive embodiment of the method according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figures 1 to 4 are schematic views of the steps for the transfer of the rows of knitting of the two portions of knitting to be joined on the group of joining needles;
Figure 5 is a view of a first way of transferring a row of knitting of one of the portions of knitting to be joined from the engagement elements of the dial to the group of joining needles of the needle cylinder;
Figures 6 to 10 illustrate a second way of transferring a row of knitting of one of the portions of knitting to be joined from the engagement elements of the dial to the group of joining needles of the needle cylinder.

Ways of carrying out the Invention

The method according to the invention is meant to be performed preferably with a circular hosiery knitting machine provided with a needle cylinder 1, which has a vertical axis 1a, and with a dial 4, which faces upwardly and coaxially the needle cylinder 1; said needle cylinder and said dial can each be actuated by means of a corresponding electric motor, with the possibility to manage electronically the way in which the two electric motors are actuated so as to turn, in some steps of the operation of the machine, the dial 4 rigidly or jointly with respect to the needle cylinder 1 about the common axis 1a and turn, in other steps of the operation of the machine, the dial 4 with respect to the needle cylinder 1 through angles which can vary according to the different operating requirements.
The dial 4 of the machine is provided with engagement elements, which can be actuated in order to engage loops of knitting 60 of a row of knitting produced by the needles of the needle cylinder 1 or in order to release loops of knitting 60, previously engaged, to needles of the needle cylinder 1.
Each engagement element can be constituted, in a per se known manner, by a needle or by at least one pusher or by at least one hook.
Depending on the type of machine and on the operating requirements, if the engagement elements are constituted by pushers or hooks, each engagement elements can comprise two or more elements arranged side-by-side, which cooperate with each other in order to engage a loop of knitting 60 to be transferred and then transfer it to a needle of the needle cylinder 1.
More particularly, in the dial 4 there are a plurality of radial slots, which are omitted in the figures for the sake of simplicity and inside each of which there is an engagement element, which can move on command along the corresponding radial slot in order to pass from an extracted position, in which it protrudes from the peripheral profile of the dial 4 in order to interact with at least one needle of the needle cylinder 1, engaging a loop of knitting 60 of a row of knitting formed by the needles of the needle cylinder 1 or releasing a loop of knitting 60 engaged previously to a needle of the needle cylinder 1, to a retracted position, in which it is retracted within the dial 4 so as to retain the loop of knitting 60 engaged previously and/or not interfere with the needles of the needle cylinder 1.
The movement of the engagement elements along the corresponding radial slots of the dial 4 in order to transfer them from the extracted position to the retracted position or vice versa is achieved by providing, in a per se known manner, the engagement elements with one or more heels which protrude upwardly from the dial 4 and can engage actuation cams, which face upwardly the dial 4 and with respect to which the dial 4 turns, like the needle cylinder 1, about its own axis 1a during the operation of the machine.
The dial 4, particularly when the engagement elements are constituted by needles, can be provided with selection devices which allow to select even individually which engagement elements must be moved from the retracted position to the extracted position or vice versa. One of these devices is disclosed for example in US Patent no. 6,014,875 by the same Applicant.
If the engagement elements are constituted by needles, as shown in Figures 5 to 10, said needles have, in a per se known manner, a lateral spring 50, which forms, on the side of the shank of the needle, in a region which is spaced from the region where the needle latch acts, a slot 51, astride which it is possible to arrange the loop of knitting 60 that must be transferred and into which the tip of the needle of the needle cylinder 1 that must receive said loop of knitting 60 can be inserted. The needles of the needle cylinder 1, if they can release loops of knitting 60 to the needles of the dial 4, are provided likewise with a lateral spring, which defines, on the side of the shank of the needle, in a region which is spaced from the region where the latch of the needle acts, a slot astride which it is possible to arrange the loop of knitting that must be transferred and in which the tip of the needle of the dial 4 that must receive said loop of knitting can be inserted.
The method according to the invention, in its more general embodiment, comprises a step for producing, with a first group of needles arranged in a first sector A of the needle cylinder 1, at least one first portion of knitting 2, which is composed of a plurality of rows of knitting, and a step of producing, with a second group of needles arranged in a second sector B of the needle cylinder 1, which is angularly spaced with respect to the first sector A around the axis 1a of the needle cylinder 1, at least one second portion of knitting 3 composed of a plurality of rows of knitting.
The method comprises a first step for transferring at least one row of knitting of the second portion of knitting 3 to at least part of the needles of a group of joining needles arranged in a third sector C of the needle cylinder 1, which is interposed between the first sector A and the second sector B, and a second step for transferring at least one row of knitting of the first portion of knitting 2 to at least part of the needles of the group of joining needles.
Both the first transfer step and the second transfer step are performed by using the engagement elements arranged in the dial 4 and by means of an angular offset of the dial 4 with respect to the needle cylinder 1.
The transfer steps have been referenced as "first transfer step" and "second transfer step" only in order to distinguish them from each other, but not to give an order of occurrence to the two steps, since depending on the joining requirements of the portions of knitting 2 and 3 it is possible to perform first the first transfer step or the second transfer step.
Each one of the transfer steps comprises a step for engaging, by means of the engagement elements arranged in a sector D, E of the dial 4, a row of knitting of the first portion of knitting 2 formed by the first group of needles, arranged in the first sector A, or a row of knitting of the second portion of knitting 3 formed by the second group of needles arranged in the second sector B, a step for the angular offset of the dial 4 with respect to the needle cylinder 1 about its axis 1a in order to arrange the sector D, E of the dial 4 so that it is closer to, or faces, the third sector C of the needle cylinder 1, and a step for releasing the row of knitting of the first portion of knitting 2 or of the second portion of knitting 3, previously picked up by the engagement elements of the dial 4, from the engagement elements of the dial 4 to the needles of the group of joining needles, which are arranged in the third sector C of the needle cylinder 1.
After the transfer step, the method comprises a step for forming at least one row of knitting by means of the group of joining needles, which are arranged in the third sector C of the needle cylinder 1 and are engaged with the portions of knitting 2 and 3, so as to provide the seamless joining of the first portion of knitting 2 with the second portion of knitting 3, as will become better apparent hereinafter.
Finally, the two portions of knitting 2, 3 thus joined are released by the joining needle assembly.
Preferably, the step for producing the first portion of knitting 2 is performed simultaneously with the step for producing the second portion of knitting 3 respectively by means of the first group of needles of the sector A and by means of the second group of needles of the sector B of the needle cylinder 1.
The engagement step can be performed by picking up the final row of knitting produced by the needles of the first group of needles in the sector A of the needle cylinder 1 and/or the final row of knitting produced by the needles of the second group of needles in the sector B of the needle cylinder 1, by means of the engagement elements located in the dial 4. In this case, the first portion of knitting 2 is released by the needles of the first group of needles of the needle cylinder 1 and/or the second portion of knitting 3 is released by the needles of the second group of needles of the needle cylinder 1 to the engagement elements of the dial 4.
As an alternative, the engagement step can be performed also at the beginning of the formation of the first portion of knitting 2 formed by the first group of needles of the needle cylinder 1 and/or of the second portion of knitting 3 formed by the second group of needles of the needle cylinder 1, as provided in the illustrated embodiment, or in an intermediate step of the forming of the portions of knitting 2, 3. In this case, the engagement elements of the dial 4, during the formation of the first row of knitting or of an intermediate row of knitting of the first portion of knitting 2 and/or of the second portion of knitting 3, are moved into the extracted position so that the thread fed to the needles of the first group of needles and/or of the second group of needles of the needle cylinder 1 is engaged also by the engagement elements of the dial 4, which are thus returned to the retracted position so as to retain the yam engaged previously while the needles of the first group of needles and/or of the second group of needles of the needle cylinder 1 continue forming the corresponding portion of knitting.
Depending on the joining requirements of the portions of knitting 2 and 3, the rows of knitting picked up by the engagement elements of the dial 4 can be the initial or intermediate rows of knitting of both portions of knitting 2 and 3, or can be the final rows of knitting of both of the portions of knitting 2 and 3, or can be the initial or final row of knitting of a portion of knitting and an intermediate row of knitting of the other portion of knitting.
Depending on the requirements, during the transfer of the rows of knitting of the first portion of knitting 2 and/or of the second portion of knitting 3 it is possible to maintain or reverse the orientation of the row of knitting that is transferred.
More particularly, if the orientation of the row of knitting is to be maintained during transfer, after engaging it by means of the engagement elements arranged in the dial 4, as explained above, the sector of the dial 4 in which the engagement elements engaged with the row of knitting to be transferred are arranged is made to face the third sector C of the needle cylinder 1, in which the joining needles are arranged, and then the loops of knitting are passed from the engagement elements of the dial 4 to the joining needles. This passage is performed without increasing or decreasing the offset of the dial 4 with respect to the needle cylinder 1 performed previously in order to make the sector of the dial 4 that supports the row of knitting to be transferred face the third sector C of the needle cylinder 1, as shown in Figure 5. This figure assumes that needles are used as engagement elements and shows the passage of a row of knitting from three needles 44, 45, 46 arranged in a sector E of the dial 4 to three joining needles 11, 12, 13 arranged in the third sector C of the needle cylinder 1.
The number of joining needles and of needles that constitute the engagement elements of the dial 4 may of course vary according to the requirements.
If the orientation of a row of knitting is to be reversed during transfer, transfer is performed by starting the release of the row of knitting from the engagement elements arranged in one sector of the dial 4 after the two angularly mutually closest or furthest ends of this sector of the dial 4 and of the third sector C of the needle cylinder 1 have been made to face each other and by releasing the row of knitting by means of the transfer, in each instance, of a loop of knitting from the dial to a joining needle, gradually increasing or decreasing, between the passage of one loop of knitting and the passage of a contiguous loop of knitting, the angular offset of the dial 4 with respect to the needle cylinder 1 around its axis 1a, until the transfer of the row of knitting from the dial 4 to the joining needles is completed.
This transfer technique is shown in Figures 6 to 10, assuming that needles are used as engagement elements and only as regards three needles 41, 42, 43 arranged in a sector D of the dial 4 which must release the previously picked-up loops of knitting to three joining needles 11, 12, 13 of the third sector C of the needle cylinder 1. With reference to these figures, after making the mutually closest ends of the sector D and of the sector C face each other, by means of the offset of the dial 4 with respect to the needle cylinder 1, the loop of knitting 60 is released by the needle 41 of the dial 4 to the needle 13 of the needle cylinder 1, as shown in Figure 7, and then the offset of the dial 4 with respect to the needle cylinder 1 is increased and the loop of knitting 60 is released by the needle 42 of the dial 4 to the needle 12 of the needle cylinder 1, as shown in Figure 8, and then the offset of the dial 4 with respect to the needle cylinder 1 is increased further and the loop of knitting 60 is released by the needle 43 of the dial 4 to the needle 11 of the needle cylinder 1, as shown in Figure 9.
The reversal of the orientation of the row of knitting of the first portion of knitting 2 in passing from the sector D of the dial 4 to the needles of the group of joining needles might also be performed by starting the release from the needle 43 of the dial 4 to the needle 11 of the needle cylinder 1 and by ending with the release from the needle 41 of the dial 4 to the needle 13 of the needle cylinder 1, and the angular offset between the dial 4 and the needle cylinder 1 might be performed both clockwise and counterclockwise.
The expression "the ends of the sectors" of the needle cylinder 1 and of the dial 4 respectively is used to designate the ends of the sectors that are occupied by needles involved in the transfer of the loops of knitting 60.
The release of the loops of knitting 60 from each needle of the dial 4 to the corresponding needle of the needle cylinder 1 is performed by moving the needle of the dial 4 into the extracted position so as to arrange, in each instance, the loop of knitting 60 that must be released so that it straddles the slot 51 formed by the lateral spring 50 on the side of the needle of the dial 4 and so as to align said slot 51 with the needle of the needle cylinder 1 that must receive the loop of knitting 60. The needle of the needle cylinder 1 is then inserted through the slot 51 and the needle of the dial 4 is then moved to the retracted position so as to abandon the loop of knitting 60 on the needle of the needle cylinder 1, as shown in particular in Figures 7, 8 and 9.
The needles of the dial 4 which must release the loop of knitting 60, as well as the needles of the needle cylinder 1 which must receive the loop of knitting 60, are selected, by means of corresponding selection devices of a known type, as mentioned above, so as to perform in each instance the extraction of one needle of the dial 4 and then its retraction into the dial 4, as well as the lifting and then the lowering of the needle of the needle cylinder 1 that must receive the loop of knitting 60, before increasing or decreasing the offset of the dial 4 with respect to the needle cylinder 1 and then extract the contiguous needle of the dial 4. The extraction and retraction movement of the needles of the dial 4 and the lifting and lowering movement of the needles of the needle cylinder 1 can be achieved by actuating the needle cylinder 1 and the dial 4 with a continuous rotary motion about their axis 1a, or by actuating them with an alternating rotary motion about said axis 1a with respect to the cam or cams of the dial 4 that actuate the extraction and retraction of the needles of the dial 4 and with respect to the cams that lift and lower the needles of the needle cylinder 1.
It should be noted that the orientation of the row of knitting of the first portion of knitting 2 or of the row of knitting of the second portion of knitting 3 that is transferred can be reversed, instead of during the step for releasing the row of knitting to the group of joining needles, during the step for engaging said row of knitting if said engagement step consists of a release of the row of knitting from the needles of the first group of needles or of the second group of needles to the engagement elements of the dial 4. In this case, the passage of the row of knitting from the needles of the first group of needles or of the second group of needles to the engagement elements of the dial 4 begins after the two angularly mutually closest or furthest ends of the sector D or E of the dial 4 and of the sector A or B of the needle cylinder 1 have been made to face each other and by performing the passage, in each instance, of one loop of knitting from a needle of the sector A or B to an engagement element of the sector D or E of the dial 4, gradually increasing or decreasing, between the passage of one loop of knitting and the passage of a contiguous loop of knitting, the angular offset of the dial 4 with respect to the needle cylinder 1 around its axis 1a, until the transfer of the row of knitting from the needles of the first group of needles or of the second group of needles to the engagement elements of the dial 4 is completed.
The actuation of the needles of the first group of needles or of the second group of needles which must release the row of knitting and of the engagement elements of the dial 4 which must receive the row of knitting can be performed in a manner similar to what has been described above with reference to the release of the row of knitting from the dial to the group of joining needles.
By means of the reversal of the orientation of the row of knitting of the first portion of knitting 2 or of the second portion of knitting 3 during its transfer, it is possible to compensate for the rotation that the portion of knitting 2 or the second portion of knitting 3 undergoes as a consequence of the offset of the dial 4 with respect to the needle cylinder 1 or increase said rotation in order to obtain a twisting of the portion of knitting 2, depending on the effect that one wishes to obtain on the item of clothing.
The method according to the invention, in a preferred embodiment, shown in the figures, comprises a step for producing, with a first group of needles arranged in a first sector A of the needle cylinder 1, a first portion of knitting 2 composed of a plurality of rows of knitting and, with a second group of needles arranged in a second sector B of the needle cylinder 1, a second portion of knitting 3 composed of a plurality of rows of knitting.
The loops of the initial row of the first portion of knitting 2 and of the second portion of knitting 3 are engaged with the engagement elements arranged respectively in a first sector D and in a second sector E of the dial 4, which in this phase face the sectors A and B of the needle cylinder 1 (Figure 1).
Subsequently, when the portions of knitting 2 and 3 have reached a sufficient length, a first step is performed to transfer the row of knitting of the second portion of knitting 3 engaged by the engagement elements arranged in the second sector E of the dial 4 to the needles of a group of joining needles of the needle cylinder 1 arranged in a third sector C of the needle cylinder 1 interposed between the first sector A of the needle cylinder 1 and the second sector B of the needle cylinder 1 (Figure 2).
This transfer step is performed without reversing the orientation of the row of knitting previously retained by the engagement elements arranged in the sector E of the dial 4, as described above with reference to Figure 5. In this case, the transfer is performed by offsetting, counterclockwise in the figures, the dial 4 with respect to the needle cylinder 1.
In practice, if the reference signs C1, C2 and E1, E2 designate the ends of the third sector C of the needle cylinder 1 and of the second sector E of the dial 4 involved in this first transfer step and the reference signs b1', b2' designate the ends of the row of knitting of the second portion of knitting 3 retained by the sector E of the dial 4, the ends b1', b2' of the row of knitting of the second portion of knitting 3 retained by the needles of the sector E of the dial 4 pass from E1 to C1 and from E2 to C2 (Figure 2).
In this manner, the second portion of knitting 3 is provided on the joining needles of the third sector C of the needle cylinder 1 with its reverse side directed toward the outside of the needle cylinder 1.
A second step is then performed to transfer the row of knitting of the first portion of knitting 2 engaged by the engagement elements arranged in the first sector D of the dial 4 to the needles of the group of joining needles that already support the row of knitting of the second portion of knitting 3 transferred previously.
The passage of the first portion of knitting 2 from the engagement elements of the first sector D of the dial 4 to the joining needles of the third sector C of the needle cylinder 1 is performed by reversing the orientation of the row of knitting during transfer. In this case, the transfer is performed by offsetting, clockwise in the figures, the dial 4 with respect to the needle cylinder 1 and by gradually increasing the offset during the transfer, as described above with reference to Figures 6 to 10.
In practice, if D 1 and D2 designate the ends of the first sector D of the dial 4, the transfer of the first portion 2 achieves the passage of the ends a1', a2' of the row of knitting of the first portion of knitting 2 retained by the engagement elements of the sector D of the dial 4 from D1 to C2 and from D2 to C1 (Figure 3).
In this manner, the first portion of knitting 2 is arranged on the needles of the third sector C of the needle cylinder 1 so that it is orientated with its reverse side directed toward the axis 1a of the needle cylinder 1.
The transfer performed in this second transfer step reverses, during the transfer, the first portion of knitting 2 with respect to what would be obtained by performing a transfer by making the first sector D of the dial 4 and the third sector C of the needle cylinder 1 face each other and without increasing the offset of the dial 4 with respect to the needle cylinder 1 between the transfer of a loop of knitting 60 and the contiguous loop of knitting 60.
This compensates for the rotation that the portion of knitting 2 undergoes as a consequence of the offset of the dial 4 with respect to the needle cylinder 1, arranging the first portion of knitting 2 so that it is oriented correctly with respect to the second portion of knitting 3 on the joining needles in order to be joined thereto without undergoing or inducing any twisting.
The needles of the third sector C of the needle cylinder 1 are then actuated so as to produce one or more rows of knitting, with ladder-proof or ladder-resistant structures, for joining the two portions of knitting 2, 3 before releasing the article, the production whereof can therefore be continued with the needles arranged in the first sector A and in the second sector B of the needle cylinder 1 (Figure 4).
This embodiment of the method according to the invention can be used for example to perform the seamless joining of the two flaps of the crotch of articles such as underpants or the like.
The method according to the invention has been explained exclusively as regards the joining of two portions of knitting, but it can be used to join, directly on the production machine, a plurality of pairs of portions of knitting produced by the needles arranged in different sectors of the needle cylinder, optionally providing a plurality of sectors, each of which supports a group of joining needles, for example in order to join straps of body suits or bras without seams.
Moreover, in the illustrated embodiment, the method according to the invention has been explained under the assumption of seeking to eliminate the twisting of the portions of knitting that are joined, but the variation of the orientation of the portions of knitting during their transfer on the group of joining needles can be used in order to increase this twisting if required for aesthetic purposes or other purposes.
For the sake of greater simplicity, the method according to the invention has been described under the assumption that the two rows of knitting of the two portions of knitting that are joined have the same extension, but the joining of the two portions of knitting might also be performed between two rows which have mutually different dimensions, involving in the joining only a part of the longest row of knitting.
In practice it has been found that the method according to the invention fully achieves the intended aim, since it allows to provide, directly on the circular hosiery knitting machine with two beds or the like, used to produce an article, the joining of portions of knitting produced by groups of needles which are located in sectors of a bed which are mutually angularly spaced around the axis of the bed, thus avoiding subsequent stitching operations.
The method thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.
In practice, the materials used, as well as the dimensions, may be any in accordance to requirements and to the state of the art.

Claims

A method for joining portions of knitting produced by at least two mutually spaced groups of needles of a bed in circular hosiery knitting machines with two beds or the like, comprising two coaxial and mutually facing beds, respectively a first bed (1) provided with needles (11,12,13) which can be actuated in order to produce knitting and a second bed (4) provided with engagement elements (41,42,43) which can be actuated in order to retain or pick up loops of knitting (60) formed by the needles (11,12,13) of the first bed (1) or to release loops of knitting (60) previously retained or picked up to the needles (11,12,13) of the first bed (1), characterized in that it comprises:
- a step for forming, with a first group of needles arranged in a first sector (A) of the first bed (1), at least one first portion of knitting (2) composed of a plurality of rows of knitting;

- a step for forming, with a second group of needles arranged in a second sector (B) of the first bed (1) which is angularly spaced from said first sector (A) of the first bed (1) around the axis (1a) of the first bed (1), at least one second portion of knitting (3) composed of a plurality of rows of knitting;

- a first step for transferring at least one row of knitting of the second portion of knitting (3) to at least part of the needles of a group of joining needles arranged in a third sector (C) of the first bed (1) which is interposed between said first sector (A) and said second sector (B) of the first bed (1), said first transfer step being performed by means of said engagement elements of the second bed (4) and by means of an angular offset of the second bed (4) with respect to the first bed (1) around its axis (1a);

- a second step for transferring at least one row of knitting of the first portion of knitting (2) to at least part of the needles of said group of joining needles, said second transfer step being performed by means of said engagement elements of the second bed (4) and by means of an angular offset of the second bed (4) with respect to the first bed (1) around its axis (1a);

- a step for forming at least one row of joining knitting by means of the needles of said group of joining needles, which are engaged with said first portion of knitting (2) and with said second portion of knitting (3) which joins said first portion of knitting (2) to said second portion of knitting (3);

- a step for disengaging said group of joining needles from said portions of knitting.
The method according to claim 1, characterized in that each one of such transfer steps comprises:
- a step for engaging, by means of the engagement elements arranged in a sector (D,E) of the second bed (4) of the machine, a row of knitting formed by said first group of needles arranged in said first sector (A) of the first bed (1) or a row of knitting formed by said second group of needles arranged in said second sector (B) of the first bed (1);

- a step for the angular offset of the second bed (4) with respect to the first bed (1) around the axis (1a) of the first bed (1) in order to make said sector (D,E) of the second bed (4) move closer to, or face, said third sector (C) of the first bed (1);

- a step for releasing the row of knitting previously engaged by said engagement elements from the engagement elements arranged in said sector (D,E) of the second bed (4) to said group of joining needles arranged in said third sector (C) of the first bed (1).
The method according to claim 1, characterized in that said step for the production of a first portion of knitting (2) and said step for the production of a second portion of knitting (3) are performed simultaneously respectively by means of said first group of needles and by means of said second group of needles.
The method according to one or more of the preceding claims,
characterized in that the row of knitting of the first portion of knitting (2) and/or of the second portion of knitting (3) that is engaged by said engagement elements and transferred to at least part of the needles of said group of joining needles is constituted by the first row of knitting formed by said first group of needles or by said second group of needles.
The method according to one or more of the preceding claims,
characterized in that the row of knitting of the first portion of knitting (2) and/or of the second portion of knitting (3) that is engaged by said engagement elements and transferred to at least part of the needles of said group of joining needles is constituted by an intermediate row of knitting formed by said first group of needles or by said second group of needles.
The method according to one or more of the preceding claims,
characterized in that the row of knitting of the first portion of knitting (2) and/or of the second portion of knitting (3) which is engaged by said engagement elements and transferred to at least part of the needles of said group of joining needles is constituted by the last row of knitting formed by said first group of needles or by said second group of needles.
The method according to one or more of the preceding claims,
characterized in that it comprises reversal of the orientation of the row of knitting of said first portion of knitting (2) and/or of said second portion of knitting (3) that is transferred, in at least one of said transfer steps.
The method according to claim 7, characterized in that said reversal of the orientation of the row of knitting is performed during the step for the release of said row of knitting of the first portion of knitting (2) or of said second portion of knitting (3) from said engagement elements of the second bed (4) to the needles of said group of joining needles.
The method according to claim 8, characterized in that said release step begins after the angularly mutually closest or furthest ends of said sector (D,E) of the second bed (4) and of the third sector (C) of the first bed (1) have been made to face each other, and is performed by means of the passage, in each instance, of a loop of knitting from the second bed (4) to a needle of said group of joining needles (11,12,13), gradually increasing or decreasing, between the passage of one loop of knitting and the passage of the contiguous loop of knitting, the angular offset of the second bed (4) with respect to the first bed (1), until the transfer of the row of knitting from the second bed (4) to the needles of said group of joining needles (11,12,13) is completed.
The method according to one or more of the preceding claims,
characterized in that said engagement step is performed by means of the passage of a row of knitting from said first group of needles or said second group of needles to the engagement elements (41,42,43) arranged in said sector (D) of the second bed (4), said reversal of the orientation of the row of knitting being performed during said engagement step.
The method according to claim 10, characterized in that said engagement step begins after the angularly mutually closest or furthest ends of said sector of the second bed (4) and of the first sector (A) or of the second sector (B) of the first bed (1) have been made to face each other and is performed by means of the passage, in each instance, of a loop of knitting from a needle of said first group of needles or of said second group of needles to an engagement element which is arranged in said sector (D,E) of the second bed (4), gradually increasing or decreasing, between the passage of one loop of knitting and the passage of the contiguous loop of knitting, the angular offset of the second bed (4) with respect to the first bed (1) until the row of knitting is transferred completely from said first group of needles or from said second group of needles to the engagement elements arranged in said sector (D,E) of the second bed (4).
The method according to one or more of the preceding claims,
characterized in that one of said transfer steps is performed without reversing the orientation of the transferred row of knitting and in that the other one of said release steps is performed with a reversal of the orientation of the transferred row of knitting.
A method for joining portions of knitting according to claim 1,
wherein said first bed is the needle cylinder (1) and said second bed is the dial (4) of a circular hosiery knitting machines with a needle cylinder (1) and a dial (4) arranged above and coaxially with respect to the needle cylinder (1)
and wherein the at least one row of knitting of the
transfer steps is the initial row of knitting
wherein said first transfer step comprises:
- a first step for engaging the initial row of knitting formed by said second group of needles arranged in said second sector (B) of the needle cylinder (1); said first engagement step being performed, during the production of said second portion of knitting (3), by means of the engagement elements arranged in a second sector (E) of the dial (4) of the machine;

- a first step for the angular offset of the dial (4) with respect to the needle cylinder (1) around the axis (1a) of the needle cylinder (1), in order to make said second sector (E) of the dial (4) face said third sector (C) of the needle cylinder (1);

- a first step for releasing the row of knitting of said second portion of knitting (3), previously engaged by said engagement elements, to the needles of said group of joining needles (11,12,13); said second transfer step comprises

- a second step for engaging the initial row of knitting formed by said first group of needles arranged in said first sector (A) of the needle cylinder (1); said second engagement step being performed, during the production of said first portion of knitting (2), by means of the engagement elements (41,42,43) arranged in a first sector (D) of the dial (4) of the machine;

- a second step for the angular offset of the dial (4) with respect to the needle cylinder (1) around the axis (1a) of the needle cylinder
(1) in order to move said first sector (D) of the dial (4) closer to the third sector (C) of the needle cylinder (1);

- a second step for releasing the row of knitting of said first portion of knitting (2), engaged previously by said engagement elements (41,42,43), to the needles of said group of joining needles (11,12,13);
said first release step being performed after the positioning of the second sector (E) of the dial (4) so that it faces the third sector (C) of the needle cylinder (1), said second release step beginning after the mutual facing of the angularly closest ends of the first sector (D) of the dial (4) and of the third sector (C) of the needle cylinder (1) and being performed by means of the passage, in each instance, of a loop of knitting from the dial (4) to a needle of said group of joining needles (11,12,13), gradually increasing, between the passage of a loop of knitting and the passage of the contiguous loop of knitting, the angular offset of the dial (4) with respect to the needle cylinder (1) until the transfer of the row of knitting of said first portion of knitting (2) from the dial (4) to the needles of said group of joining needles (11,12,13) is completed.
Use of a circular hosiery knitting machine that comprises:
- a needle cylinder (1), which can be actuated with a rotary motion about its own axis (1a), which is arranged vertically;

- a dial (4), which is arranged above and coaxially with respect to the needle cylinder:

- knitting engagement elements (41,42,43,44,45,46), which are arranged in said dial (4) and can be actuated in order to retain or pick up loops of knitting (60) formed by the needles of the needle cylinder (1) or to release loops of knitting previously retained or picked up to the needles of the needle cylinder (1);

- a first electric motor (M1) for actuating the needle cylinder (1) with a rotary motion about its own axis (1a);

- a second electric motor (M2) for actuating the dial with a rotary motion about its own axis (1a);

- a system for the electronic control (ECS) of the driving of said electric motors (M1,M2), for rigidly coupled actuation of said needle cylinder (1) and of said dial (4) with a rotary motion about the common axis (1a) or angular offset of said dial (4) with respect to said needle cylinder (1) about the common axis (1a), for performing the method according to one or more of the preceding claims