GB2062032A

GB2062032A - The production of knitted fabric on a circular knitting machine

Info

Publication number: GB2062032A
Application number: GB8031360A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-10-04
Filing date: 1980-09-29
Publication date: 1981-05-20
Also published as: AU6293880A; ZA806002B; ES8205438A1; IL61181A0; BE885519A; JPS56154551A; FR2466554A1; IT7909555A0; ES495579A0; NL8005489A; DE3035736A1; IT1166005B; DD154721A5

Abstract

A knitted article such as a pair of tights is knitted in two parts on a circular knitting machine, with the two parts being joined directly by the machine. During the knitting of the body area of the first part, successive pairs of hooks of a welt dial engage stitches formed on two needles adjacent to, and on opposite parts of a longitudinal cut line. After each pair of hooks have taken the stitches, the welt dial is displaced angularly relative to the needle cylinder, for a multiple of the pitch between the needles. During the initial knitting of the second part of the article in the body area, the stitches are transferred progressively from the pairs of hooks to the needles and therefore to the fabric, the wet dial being displaced angularly relative to the needle cylinder between the stitch transfer from successive pairs of hooks. <IMAGE>

Description

SPECIFICATION The production of knitted fabric on a circular knitting machine The present invention relates to a method for knitting, on a circular knitting machine, two fabrics which are joined on the machine, and more particularly to a method for knitting an article, for example tights, in two parts which are directly joined by the machine. The invention also relates to a circular knitting machine for carrying out the method.

According to the invention, there is provided a method for the production of a knitted fabric on a circular knitting machine comprising a needle cylinder and a welt dial having hooks, by knitting two tubular fabrics which are to be joined, said method comprising knitting a body area of a first of said fabrics wherein successive pairs of hooks of the welt dial engage stitches of the first fabric adjacent and on opposite sides of a longitudinal cut line, and after engagement of the stitches by said pair of hooks, the welt dial is displaced angularly relative to the needle cylinder for a multiple of the pitch between the needles; and knitting the body area of a second of said fabrics wherein the stitches engaged by the pairs of hooks are progressively transferred to the needles with progressive angular displacement of the welt dial whereby the two tubular fabrics are joined together during the formation of the body area of the second fabric.

Further according to the invention, there is provided a method for the production of a knitted article on a circular knitting machine comprising a needle cylinder and a welt dial having hooks, by knitting two parts of the article which are to be joined, said method comprising knitting a body area of a first of said parts wherein successive pairs of hooks of the welt dial engage stitches of the first part adjacent and on opposite sides of a longitudinal cut line, and after engagement of the stitches by said pair of hooks, the welt dial is displaced angularly relative to the needle cylinder for a multiple of the pitch between the needles; and knitting a body area of a second of said parts wherein the stitches engaged by the pairs of hooks are progressively transferred to the needles with progressive angular displacement of the welt dial whereby the two parts of the article are joined together during the formation of the body area of the second part.

During the formation of the body areas of the two parts, the latter may also be cut directly along lines of cut flanked by the stitches engaged by the pairs of hooks.

The engagement of the first part by the successive pairs of hooks, and the unloading of the stitches from the successive pairs of hooks to the second part in formation may be separated by several rows of stitches, for example with three bridges of three contiguous rows, followed by five non-engaged rows.

The displacement of the dial after the engagement of the stitches by a pair of hooks is preferably equal to at least twice the pitch between hooks, the hooks of each pair being separated by a multiple of the pitch of the needles which is different from the pitch of the displacement.

Further according to the invention there is provided a circular knitting machine comprising a needle cylinder having needles, a welt dial having hooks, means for producing intermittent angular displacement of the welt dial relative to the needle cylinder, the angular displacement being a multiple of the pitch between adjacent hooks, means for effecting, between successive angular displacements of the dial, the radial displacement of a pair of hooks temporarily facing a predetermined pair of said needles, and means for controlling the said pair of needles, to bring about the cooperation of the said pair of needles and successive pairs of hooks for the engagement of the stitches by said needles, and for the discharge of the stitches to said needles.

In a preferred embodiment, a first rotatable assembly comprising a disc-like support is operated by a transmission for rotation synchronously and coaxially with the needle cylinder and independently of a second rotatable assembly comprising the welt dial. The second assembly is actuated by the first assembly through an endless screw system, or the like, having intermittent movement through cyclic engagement of a gear rigid with the endless screw with fixed toothing, or in succession with one or the other of two sets of toothing, fixed and selectively or simultaneously excludable.The disclike support carries controllable thrust means with cam profiles to act after intervals of a desired number of rows on the two hooks which are temporarily situated facing the pair of needles, during the engagement or the unloading of the stitches on the part of the pairs of hooks, which may each also support two or more stitches.

The two needles of the pair of needles cooperating with successive pairs of hooks and the successive angular displacements of the welt dial are selected in such a way so that the cooperation is ensured with one of the needles of the pair, of the hooks of a set of hooks intercalated with those of another different set, which cooperate with the other needle of the pair. The two needles cooperating with successive hooks may be separated from one another by the presence of a number of needles adapted to form two edges of stitches resistant to coming undone, between the line of cut and the rows of stitches formed by the pair of needles.A cutting arrangement -- such as a needle with a cutter blade operating on the lifting of the needle, and a hot system - is provided for longitudinally cutting the fabric, during the formation of the respective areas of the body.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is an overall vertical section of a circular knitting machine in accordance with the invention; Figure 2 is a section on line Il-Il of Figure 1; Figures 3 and 4 show, in isolation, views of a disc-like support; Figure 5 shows an enlarged detail in section along line V-V of Figure 3; Figure 6 shows in perspective a control slider for the hooks of a welt dial; Figures 7A-7M show different phases in the cooperation between the needles and hooks for the transfer of stitches; Figures 8A--8E show in schematic axial view, different stages of holding and transferring stitches associated with the hooks;; Figure 9 is a local section on line IX-IX of Figure 1; Figures 1 OA-1 OH and 11 A-1 1 H show schematically a garment in separate perspective views in different stages of formation, on the machine, and removed from the machine; Figure 12 shows in perspective the garment during formation; Figure 13 is a section on line XIll-XlII of Figure 12; Figures 1 4A to 1 4D are developed views showing the progressive engagement of portions of the fabric by the hooks; Figure 1 5 shows in cross-section a detail of the needle cylinder and the welt dial during cutting of the fabric; Figures 16, 17 and 18 show in perspective three stages in the formation of a garment, according to a modified form of the process;; Figure 1 9 is a section similar to Figure 1 and showing a modified embodiment; and Figure 20 is a section on line xX-XX of Figure 19.

As illustrated in the accompanying drawings, to obtain the operation of the machine as defined hereinabove the machine is modified in the manner described hereinafter. Referring initially to Figures 1 and 2, 51 denotes the needle cylinder carrying an external annular support 53 on which sinkers 55 are radially slidably mounted, the sinkers cooperating with needles 57. 59 denotes a welt dial having radial slots in which welt hooks 61 slide. The welt dial is disposed immediately above the upper end of the needle cylinder and coaxially with it, below a fixed (and possibly removable) structure 63 which carries means for actuating the dial and cam means for the control of the hooks.As is known, the welt dial 59 rotates normally at the same speed as the needle cylinder, and the hooks carry stitches during specific working phases, in particular for making a socalled "turned welt" or "double edge"; these stitches may be returned to the corresponding needles.

Operations of the above type are illustrated in particular in Figures 7A to 7M. To engage a stitch on a hook 61, the hook (formed by two symmetrical resilient members which define an eye) is displaced radially outwards from a rest position shown in Figure 7A, where the stitches are normally formed by the raising and lowering of the needles 57. When a stitch is to be taken onto a hook, the needle 57X (Figure 7E) corresponding to the hook is kept lowered, the hook 61 is advanced partly forwards in the direction of the arrow FE of Figures 7B to 7E, while the needles 57Y which flank the hook under consideration are raised. The needles 57Y take up the thread (Figure 7B) and on lowering form a thread bridge PF engaged by the partly-advanced hook 61.This bridge represents the stitch engaged by the actual hook which, after the lowering of the needles 57Y, is moved back to the withdrawn position, of Figure 7D; the stitches are subsequently formed by the needles. When a bridge stitch PF has to be given back by a hook to a needle and in particular to needle 57X, the hook 61 is made to advance outwardly in the direction of the arrow fF of Figures 7F and 7G until it brings the eye formed by the two members of the hook facing the needle 57X while the needle is still in a lowered position; the needle 57X is subsequently raised as shown by the sequence of Figures 7F, 7H, 7L, 7M, while the hook is withdrawn in the radially inwards direction indicated by the arrows of Figures 7H, 7L, 7M, the two resilient members forming the hook opening widely apart at the end to run on the sides of the needle.The stitch or stitches PF of bridge type are then held by the raised needle 57X and cleared by the hook which withdraws radially inwardly. Immediately afterwards it resumes the normal formation of the stitches.

This system of forming the bridge stitches on the hooks, and of transferring the stitches from the hooks to the needles is utilised according to the preferred embodiment of the invention by acting in special manner on the dial to displace it relative to the cylinder, while, traditionally the dial must rotate in a perfectly synchronous manner with the cylinder.

It is necessary to operate every time with a different pair of hooks, replacing each time the pair of hooks by another pair of hooks, each pair of hooks cooperating with the same two needles.

The hooks of each pair which cooperate with the needles are replaced each time by a displacement, either forwards or backwards, of the dial relative to the cylinder.

To obtain the periodical displacement of the dial 59 relative to the cylinder 51, the method of operation is as follows: On the fixed structure 65 there is provided a shaft 67 of a transmission kinematically connected to the needle cylinder and normally arranged to transmit a movement to the dial which is synchronous with that of the cylinder.

This shaft 67, through a bevel gear 69, operates a bevel gear 71 which is coaxial with the needle cylinder and is mounted idly on a shaft 73 rigid with the plate 59 and mounted on the structure 63, 65. Around the shaft 73 a tubular shaft 75 is mounted, engaged at the top with the gear 71.

The tubular shaft 75 is rigid at the bottom (see also Figures 3 to 6) with a disc-like support 77 which is disposed between the dial 59 and the structure 63. This support rotates therefore exactly in a manner synchronous with the needle cylinder. This support has two radial guides 79A, 79B which correspond exactly and immutably with a pair of needles 57A and 57B at the distance from each other. In the radial guides 79A, 79B, two thrusting means are housed, each thrusting means being in the form of a slider 81, provided with a heel 83 which projects upwardly.

The two sliders 81 are each able to push a pair of hooks 61 when brought under the slider. The slider 81 is used to push the hook radially outwardly, the sliders being actuated by a cam which will be described hereinafter and acting upon the respective heels 83. Each hook moved radially outwardly by a slider 81 is returned radially inwardly by cam means to be described, which act directly on the heel of the hook to return the slider 81 also radially inwardly, or the slider 81 being beforehand returned inwardly as a result of the action of cam means on the heel 83.

To control the two sliders 81 and the hooks aligned on them, tracks and cams are provided as shown in particular in axial view in Figure 9. A cam 85 can be moved by means of a column 86 parallel with the axis of the needle cylinder and mounted on the structure 63, for insertion into an active position on the heel 83, and for exclusion. A butterfly, or angular, cam 87, also mounted on the structure 63, can assume a position 87A at the time of the loading of the stitch bridges on the hook and a position 878 for the transfer, i.e. for the discharge of the stitch bridges from the hook to the needles; this cam 87 acts upon the heels of the hooks which are protruding.

With the above cams there are further combined a track with an internal side 89A, 89B and 89C, able to act on the heels of the hooks, and an internal projection 91 adapted to produce always the return movement of the sliders 81 by acting in a radially inwards direction on the heels 83 in advance upon the cam 87. By means of the projection of the hooks the cam 85 acts upon the sliders. Along the section 89C it is possible to carry out the transfer of the stitches to the needles (Figures 7F, 7G). For the inwards return of the hooks (pushed outwards by the sliders 81) provision is made for the section 89C which supports the hooks in the loading position, which takes place along the section 89A (Figures 78, 7C).In the passage from section 89A to section 89B, there is obtained a partially withdrawn position (Figure 7D) in which the hook is positioned to retain the bridge stitches before return to the needles. After the return, which takes place on section 89C, the cam 87 is made to move into position 878 to effect the rearward movement of the hooks to the rest position.

The shaft 73, inside the shaft 75, is rigid with the plate 59 and also with a helical wheel or worm wheel 93 (see Figures 1 and 2) engaged with a screw thread or worm 95 formed on a small shaft 97 lying along a plane perpendicular to the geometrical axis common to the needle cylinder, the shaft 73, and shaft 75. The shaft 97 is mounted on a member 99 engaged by means of screws 101 with an intermediate member 103, connected by means of screws 105 to the gear 71.

It follows from the above description that, coaxially with the needle cylinder, two assemblies rotate. There rotates synchronously with the cylinder a first assembly formed at the support 67, the tubular shaft 75, the gear 71 and the members 103 and 99 supporting the shaft 97. Through the coupling formed by the worm 95 and the worm wheel 93, the movement is transmitted to a second assembly constituted by the wheel 93, the shaft 73 and the dial 59. In the absence of an angular movement of the shaft 97, the rotation of the second assembly corresponds to that of the first assembly and therefore of the support 77 and of the needle cylinder 51. By shifting the shaft 97 angularly, an angular advance or a delay is effected for the second assembly, and therefore for the dial relative to the first assembly and to the needle cylinder.

To obtain the possibility of synchronous rotation, and of intermittent advances and intermittent delays of the second assembly with respect to the first assembly and to the needle cylinder, the shaft 97 can be coupled through a transmission 109 with a bevel gear 111 disposed along an axis perpendicular to that of the two assemblies and of the cylinder. In the operation of the machine the bevel gear 111 describes a circular orbital path around the axis of the needle cylinder and of the said two assemblies (see in particular Figure 2).

Alongside the assembly 97, 95, 93, 111, a slide 113 is disposed and is able to move vertically on a guide formed by a structure 11 5 fixed on structure 65. The slide 11 3 may be, for example, lowered by spring-mounted means 11 7 or raised by means of a positive control to reach an intermediate position and a fully raised position.

The slide 11 3 has two bracket arms turned towards the circular path of the bevel gear 111, these arms supporting upper and lower toothed segments 11 9 and 121. In the lowered position of the slide 11 3 (as shown on the drawing), the upper toothed segment 11 9 turned downwards can engage with the bevel gear 111 during the travel of the latter between the two arms of the slide 113. There is obtained in this way a limited angular displacement of the gear 111 and therefore of the shaft 97 and thus a dephasing for example an advance of the second assembly 93, 73, 59, relative to the cylinder and the support 77. In an intermediate position of the slide 11 3 the bevel gear 111 travels between the arms of the slide 113, without engaging either with the toothed segment 11 9 or with the segment 121, and thus the two assemblies rotate synchronously.

With a subsequent raising of the slide 113 the lower toothed segment 1 21 is brought into engagement with the bevel gear 111, and thus a limited angular displacement of the gear 111 is obtained and therefore of the shaft 97 and a dephasing occurs which is the reverse of the preceding one - e.g. a delay - of the second assembly 93, 73, 59 of the hooks relative to the cylinder and to the support 77. To control the displacements of the slide 113, a slidable shoe 114 may be employed having a three-stepped profile upon which a roller feeler 11 3A of the slide 113 acts.

Each of the relative displacements, that is an advance or delay, imparted to the welt dial 59 relative to the needle cylinder 51 and to the support 77 is of a magnitude equal to an exact multiple of the pitch between the needles 57, in particular double the pitch between two hooks. It follows from this that after a unit advance and delay of the dial in front of the needles, the hooks are again disposed in a regular manner in front of the needles, but with the desired displacement.

Therefore, in front of the needles 57A and 57B (corresponding to the guides 79A, 798 of the support 77) successive pairs of hooks are replaced after each advance, and these pairs of hooks, successively but in reverse, can return in front of the needles 57A, 57B successively after every delay (and vice-versa).

The above-described arrangement, completed with means adapted to control the various members on the basis of a specific program (which means are of any conventional design), permits the achievement of a process for the successive formation of two tubular garments and for the coupling of one garment with the other during the formation of the second garment, and along longitudinal rows of stitches progressively formed on the second garment Although this process may be used to achieve many types of garments in which it is necessary - during the formation of a second garment -to couple to it a previously formed garment or a previously formed part of the same garment, a particularly interesting application of the process under consideration is that of achieving the coupling of two tubular parts of a pair of tights along the crutch line during the formation of the second part in the body area.

To achieve this (see in particular Figures 1 OA-1 OH, 11 A-1 1 H and 12), the procedure is as follows. First of all the formation of the first tubular part, that is, of the first leg denoted by 201 (Figures 1 OA, 11 A) is proceeded with as far as a line R indicating the rows of stitches at the lower point of the crutch. At this point the formation is effected of an area 203 which is the body area and at the same time along a row of stitches, the longitudinal cutting of the part is effected starting from a point 0 of the line R. Substantially, imagining the part stretched out, the work progresses as shown in Figures 11 A-1 1 D, producing the fabric of the body area 203 with a longitudinal cut T which is normally provided for the formation of the crutch line.Such a line is defined by the coupling of the edges or longitudinal lips L between the points O--A and 0--B of the cut T of the first fabric 201, 203, with the corresponding longitudinal edges of the cut provided in the second tubular part.

The longitudinal cut and in particular the coupling are normally effected after the formation of the two tubular parts and therefore independently on the circular knitting machine, and generally with a high degree of labour. With the above described arrangement this is effected by the same machine operating during the formation of body area 203 of the first tubular part, and during the formation of a body area 303 of the second tubular part which is formed immediately after the first part.

Figures 1 OE-1 OH and 11 E-1 H show the method of forming the second tubular part and of the progressive joining of the latter -- during its formation -- with the first tubular part. Line C representing the joining line between the two tubular parts and therefore the crutch line, extends between the body areas 203 and 303.

Subsequently, a section 301 of the second tubular part is made; this section represents the second leg, symmetrical with the first leg 201. El and E2 denote the final finishing edges of the first tubular part and the start of the second tubular part 303, 301, the two edges with the coupling delineating the waist line.

To achieve the longitudinal cut T of the first tubular part, and correspondingly that of the second tubular part, use may be made of any desired cutting device which is made to operate at the required time facing point 0, during the formation of the body area 203, and then from the start of the formation of the body area 303 until a point which corresponds to point 0.

A simple cutting arrangement may be formed by a special needle 57T (see Figure 15) which, below the latch, has a projection with a cutting edge 157T. On the needle 57T being pushed upward for normal operation, the cutting edge 1 57T remains below the plane of stitch formation, and therefore inactive. If, on the other hand, the needle 57T is pushed upward by a value greater than that required for normal operations, the cutting edge 1 57T reaches, and goes above, the stitch formation plane and therefore brings about the cutting of the stitch loop which encompasses the needle 57T. By repeating this greater raising during the formation of the body area 203 and 303, the required cuts are effected.

The position of the cutting arrangement (and in particular of the needle 57T if the latter is the system adopted) is between the needles 57A and 578 which are aligned on the sliders 81 adapted to push pairs of hooks outwards, in the manner already indicated, and to perform the procedure in question. Between the needle 57T (or more specifically between the position of cut) and the needles 57A and 57B, there are a sufficient number of needles for preventing any initial unravelling of stitches from the cut line reaching the respective rows of stitches formed by the needle 57A and the needle 57B, these two rows of stitches being equidistant from the relevant cut edge.

The operation of joining of the edges or lips L of the longitudinal cut T with the corresponding ones of the second tubular part is effected in the following manner: During the formation of the body area 203 from the front R, while the cut T is being effected, the engagement is also effected onto the welt dial of bridge stitches at a distance one from the other along the rows of stitches formed by the needles 57A, and 578 i.e. along the lips L at a limited distance from them. For the sake of demonstration, the engagement of the bridge stitches is effected facing the rows of points which flank the lips L, i.e. edges O--A and 0--B of the cut T (Figures 11 C and 11 D).To do this, immediately after the front R a first pair of hooks facing needles 57A and 57B is advanced by the action of the sliders 81. Each hook of this pair becomes loaded with a bridge stitch in the adjacent fabric, at edge O--A and 0--B respectively, in formation (see Figure 11 B).

Immediately afterwards, the hooks which have taken the first bridge stitch are withdrawn radially inwardly. This operation is shown in Figure 1 4A as effected by the pair of hooks 1 and 6. After the retraction of this first pair of hooks 1 and 6, the welt dial is displaced angularly relative to the needle cylinder, the cylinder and dial continuing to rotate. The angular displacement corresponds to twice the pitch between adjacent hooks and therefore four times the pitch between adjacent needles. It follows from this that in front of needles 57A and 57B, the hooks indicated respectively by-3 and by 8 are then presented.

These hooks are advanced radially outwardly so that each takes one or more bridge stitches formed by the needles 57X and 57Y after the formation of a certain number of rows of stitches (for example four or eight rows) of the body area 203. Hooks 3 and 8 having retracted, a further angular displacement is effected of the welt dial relative to the cylinder, thus bringing in front of the needles 57A and 57B this time the hooks denoted by 5 and by 10 (Figure 148). The operation is repeated for the entire length of the edges O--A and O--B and until edge El is formed or as far as points A and B.With the loading of the pairs of hooks and the angular displacement of the dial in the same direction after the loading of each pair, the lips L, i.e. the longitudinal edges O--A and O--B of the cut end are suspended from even and odd hooks respectively, following inside the path of the needles and the front of knitted fabric formation. This is represented in Figure 12, in the sequence of Figures 8A, 88, 8C and of Figures 14A, 148, 14C, 14D. The progressive engagement'of the longitudinal edges of the cut may be developed until the maximum of almost the entire circumference of the working front of the needles.At this point edge El is formed and the first tubular part is given up and remains attached (Figure 1 OD) to the machine only along edges L with the two series of bridge stitches engaged on the even and odd hooks respectively of the pairs of hooks progressively and successively presented to the action of the sliders 81.

Considering Figure 9 it will be observed that there is illustrated a machine with eight feeds Al, A2, A3, A4, A5, A6, A7, A8. In this case, the hooks which protrude engage three bridges of knitting fabric formed by the feeds Al, A2, A3, while with the feeds A4, A5, A6, A7, A8, rows of stitches between contiguous bridges are formed.

The cam 85 is stationary throughout the formation of the body areas 203 and 303. With a four-feed machine, the operation is by means of cyclic insertions and exclusions of the cam 85, with one cycle every other turn being effected. In each case, the control of the cam 85 may be obtained by a slide member 86a having a stepped profile and which is caused to slide by the machine program.

Reverting to the description of the operation, after the abandonment of the edge El by the needles, the finishing edge E2 of the second tubular part is started, with all the needles previously freed. The processing is effected to form initially the body area 303 along a length corresponding to that of the area 203. During the formation of this area, the longitudinal cutting engagement is kept operative and at the same time steps are taken for shifting the slide 113 to a position opposite the preceding one. This permits establishing cyclically, an angular displacement of the dial relative to the cylinder in a direction opposite to that in which the dial had been displaced during the formation of the body area 203.After each displacement and therefore after a certain number of rows of stitches, such as four or eight, the operation of the hooks is effected either in succession or in pairs to unload the successive bridge stitches of the edges or lips L from the body area 303. Therefore (see the sequences of Figures 1 OE to 1 OH and 11Eto 11 H, as weíí as Figures 8C, 8D, 8E) during the formation of the body area 303, a gradual reduction is effected of the development of the lips L engaged along the row of the hooks inside the circumference of the needles, while inside the edges L, the fabric of area 203 is progressively engaged to the corresponding area 303 of the second part in formation, as a result of the action of the progressive transfer of the bridge stitches from the hooks to the needles which operate in the area 303.

The working front of the area 303 of fabric is indicated by S and S1. In the progressive advance of the working front, the area 303 which is progressively formed is connected to area 203, along a line of connection defining the crutch line, as denoted by C in Figures 1 OF to 1 OH and 11 F to 11 H, along the edges defined between the terminal points A and B and points a and b of the front S, S1 of formation of the body area 303.

With the progressive formation of the body area 303. With the progressive formation of the body area 303, the stage is reached when the development is equal to that of the body area 203 and therefore the connection of the cutting lips of the two areas 203 and 303 reaches point 0. At this moment the bridge stitches have all been unloaded from the pairs of hooks and the connection of the two body areas 203 and 303 is completed, and the crutch line C along which the connection of the two parts has been effected by the machine is also completed. Beyond the point 0, the operation of the cutting arrangement ceases and the machine knits the leg 301 in tubular form.

It is possible to knit a non-laddering structure along the lips L of the first part and along the corresponding lips of the second part, that is to say in the area of the crutch line C where the connection occurs for the purpose of ensuring the stability of the connection effected by the transfer af the bridge stitches from the hooks to the needles. To prevent stitches from coming undone it is possible to proceed with the formation of a particular structure of the stitch with a corresponding control of the needles, to establish an adequate width of the stitch area between the cut T and the row of stitches formed by the needles 57A and 57B where the formation takes place of the bridge stitches taken from the hooks and the transfer of these stitches from the hooks to the needles.Alternatively or additionally it will be possible to use physical and/or chemical means for stabilisation of the structure, also in combination with a cutting system.

Figures 1 to 1 5 illustrate in detail an embodiment in which, at a first stage, a first leg 201 is formed starting from the foot or toe and then a first part of the body, namely body area 203, up to edge El. During the formation of the body area 203, along lines L successive stitches are engaged on two series of hooks with a progressive angular displacement of the welt dial in one direction; at a second stage, the second body area 303 is formed from the edge E2, during which a progressive angular displacement of the welt dial in the reverse direction is effected, and gradually the stitches are transferred from the hooks of the two series to form the connection of the two areas 203 and 303, and then the second leg 301 is formed up to the foot or toe.

According to a further embodiment of the invention, in the two successive stages the two parts are knitted in the same direction, for example, as shown in Figures 16 to 1 8 starting from the waist line of the body to end at the foot or toe. During the formation of the first part, from the waist line a body area 601 is formed, engaging onto the hooks the stitches along lines L starting from the points P6 up to point P8, with a displacementthrough 360C of the dial relative to the needle cylinder, except for empty displacement, that is to say without the loading of the hooks by means of a temporary exclusion of the cam 81 to reduce the height of the body area.

Then the formation of the first leg 603 proceeds in the direction of the arrow f6. After the first part 601,603 has been completed, the second body area 801 is started again from the waist line, with the formation of the stitches along f8. Having allowed for a possible previous empty displacement, the hooks which had first taken the stitches along the lines L of the first body area 601 are in a position to give up their stitches at points P6 at the start of the second body area 801, and gradually the stitches of the successive hooks are ceded, proceeding with the displacement of the dial in the same direction as that in which the stitches had been taken from the hooks of the dial.

The transfer of the stitches from the hooks to the needles, and therefore the joining along line C (Figures 17 and 18) as far as point P8 provide the connection of the body area 601 to the body area 801, as the latter is progressively formed. The formation of the body area 801 and therefore of the body as a whole having been completed, the formation of the second leg 803 as far as the foot or toe proceeds in the direction of arrows f8.

In this way, the requirement is avoided for a mechanism for reversing the angular intermittent displacement of the welt dial with respect to the cylinder, and one mechanism is provided for the progressive displacement of the dial in one direction only, and for the interruption of such displacement, when the formation of the body areas 601 and 801 is not proceeded with.

Provision may also be made for an arrangement similar to that illustrated in Figure 1, without providing for one of the two positions of engagement of the slide 11 3 and excluding one of the two toothed segments 119 or 121. Provision may also be made, as an alternative, for an arrangement with circular toothing and forward feed pawl.

The machine shown in Figures 1 9 and 20 includes means which facilitates the unloading of the stitches from the hooks during the formation of the second body areas 303 or 801. Identical references denote members identical with those of the preceding embodiment. Below the welt dial a guide structure 901 is provided, radially oriented and inclined towards the working area of the needles and which rotates at the exact speed of the needle cylinder. In the structure 901, which forms a cylinder, there is a piston rod 903 which at its outer end carries a tailpiece 905. The piston rod 903 is urged in the direction of the arrow f9 by a spring 907 and in the reverse direction by a fluid (for example air) which reaches the cylinder from a tubular shaft 909 coaxial with and internally of the shaft 73 supporting the welt dial 59. The tubular shaft 909 is engaged on an extension 99A of the member 99 which rotates at the speed of the needle cylinder. A connection 91 2 supplies compressed air to the end of the tubular shaft 909. During transfer of the stitches from the hooks 61 to the needles, the rod 903 is reciprocated and the tailpiece 905 acts in a radially'outwards direction on the stitches on the hooks in the area of the pair of hooks which must cede the stitches, to promote the freeing of the stitches from the hooks and their transfer to the needles.

The method and machine particularly described enable the two parts of the article to be joined directly by the machine, instread of being manually joined.

Claims

CLAIMS 1. A method for the production of a knitted fabric on a circular knitting machine comprising a 14. A machine according to any one of claims 9 to 13, further comprising expelling means reciprocable generally in a radial direction to promote the release of the stitches from the hooks. 1 5. A knitting machine substantially as hereinbefore described with reference to the accompanying drawings. 1 6. A method for the production of knitted fabric on a circular knitting machine substantially as hereinbefore described with reference to the accompanying drawings. 1 7. Knitted fabric when produced by a method according to any one of claims 1 to 8 or claim 16.

1 8. A pair of tights when produced by a method according to any one of claims 1 to 8 or claim 16.

needle cylinder and a welt dial having hooks, by knitting two tubular fabrics which are to be joined, said method comprising knitting a body area of a first of said fabrics wherein successive pairs of hooks of the welt dial engage stitches of the first fabric adjacent and on opposite sides of a longitudinal cut line, and after engagement of the stitches by said pair of hooks, the welt dial is displaced angularly relative to the needle cylinder for a multiple of the pitch between the needles; and knitting the body area of a second of said fabrics wherein the stitches engaged by the pairs of hooks are progressively transferred to the needles with progressive angular displacement of the welt dial whereby the two tubular fabrics are joined together during the formation of the body area of the second fabric.

2. A method for the production of a knitted article on a circular knitting machine comprising a needle cylinder and a welt dial having hooks, by knitting two parts of the article which are to be joined, said method comprising knitting a body area of a first of said parts wherein successive pairs of hooks of the welt dial engage stitches of the first part adjacent and on opposite sides of a longitudinal cut line, and after engagement of the stitches by said pair of hooks, the welt dial is displaced angularly relative to the needle cylinder for a multiple of the pitch between the needles; and knitting the body area of a second of said parts wherein the stitches engaged by the pairs of hooks are progressively transferred to the needles with progressive angular displacement of the welt dial whereby the two parts of the article are joined together during the formation of the body area of the second part.

3. A method according to claim 2, wherein during the formation of each body area, they are cut along lines of cut flanked by the stitches engaged by the pairs of hooks.

4. A method according to claim 2 or claim 3, wherein the engagement of the stitches of the first part by successive pairs of hooks, and the transfer of the stitches from said successive pairs of hooks to the fabric of the second part are separated by several rows of stitches.

5. A method according to any one of claims 2 to 4, wherein the displacement of the dial after the stitches have been taken by a pair of hooks is of a magnitude equal to at least twice the pitch between the hooks, the hooks of each pair being separated by a multiple of the pitch of the needles which is different from the pitch of the displacement.

6. A method according to any one of claims 2 to 5, wherein double finishing edges are formed along a waist line of the article.

7. A method according to any one of claims 2 to 6 for knitting an article in which each of said parts is composed of a body area and a leg portion, wherein during taking of the stitches by the hooks of the dial, the dial is displaced.

angularly in one direction relative to the needle cylinder, and during the transfer of the stitches from the hooks of the dial, the dial is displaced angularly in the reverse direction, and the first part of the article is knitted from a leg portion towards the body area, and the second part of the article is knitted from the body area towards a leg portion.

8. A method according to any one of claims 2 to 6, for knitting an article in which each of said parts is composed of a body area and a leg portion, wherein the dial is displaced angularly in the same direction during the taking and during the cession of the stitches by the hooks, and the first part of the article is knitted from the body area towards a leg portion, and the second part of the article is knitted from the body area towards a leg portion.

9. A circular knitting machine for carrying out a method as claimed in claim 1 or claim 2, comprising a needle cylinder having needles, a welt dial having hooks, means for producing intermittent angular displacement of the welt dial relative to the needle cylinder, the angular displacement being a multiple of the pitch between adjacent hooks, means for effecting, between successive angular displacements of the dial, the radial displacement of a pair of hooks temporarily facing a predetermined pair of said needles, and means for controlling the said pair of needles, to bring about the cooperation of the said pair of needles and successive pairs of hooks for the engagement of the stitches by said needles, and for the discharge of the stitches to said needles.

10. A machine according to claim 9, comprising a first driven assembly including a disc-like support rotatable synchronously and coaxially with the needle cylinder, a second driven assembly including the welt dial, means for coupling the second assembly to the first assembly for rotation therewith, and means selectively operative to cause angular displacement of the second assembly relative to the first assembly, said disc-like support carrying controllable thrust means with cam profiles operative to act, after intervals of a number of rows, on the two hooks which are temporarily situated facing the said pair of needles, during the engagement or the unloading of the stitches by the pair of hooks.

11. A machine according to claim 9 or claim 10, wherein the two needles of the said pair cooperating with successive pairs of hooks, and the extent of each angular displacement of the welt dial are such that cooperation occurs between one of the said pair of needles and the hooks of a set of hooks intercalated with those of a different set which cooperate with the other needle of said pair of needles.

12. A machine according to any one of claims 9 to 11 , wherein the two needles of said pair of needles are separated one from the other by a number of needles adapted to form two edges of fabric resistant to unravelling.

13. A machine according to any one of claims 9 to 12, further comprising cutting means for cutting longitudinally a fabric being knitted on the machine.