US3800560A

US3800560A - Machine for and method of knitting stocking with closed toe

Info

Publication number: US3800560A
Application number: US00192206A
Authority: US
Inventors: P Hanney; T Staniforth
Original assignee: Individual
Current assignee: Bentley Engineering Co Ltd
Priority date: 1970-12-02
Filing date: 1971-10-26
Publication date: 1974-04-02
Anticipated expiration: 1991-04-02

Abstract

Circular knitting method and machine in which tubular knitted fabric is closed by loop transfer from needle to needle through the remaining loops and locked by knitting, preferably preceded by wale reduction by loop transfer.

Description

United States Patent [1 1 Hanney et al.

I 11 3,800,560 14 1 Apr. 2, 1974 1 1 MACHINE FORAND METHOD OF KNITTING STOCKING WITH CLOSED TOE [75] Inventors: Philip Michael Hanney; Thomas Raymond Staniforth, both of Leicester, England [73] Assignee: The Bentley Engineering Company Limited, by said Staniforth [22] Filed: Oct. 26, 1971 [21] Appl. No.: 192,206

[30] Foreign Application Priority Data Dec. 2, 1970 Great Britain 57198/70 [52] US. Cl 66/14, 66/56, 66/95,

[51] Int. Cl D04b 9/10, D04b 9/56, D04b 15/02 [58] Field of Search 66/14, 9 R, 95, 1 R, 1 A, 66/170,172 R,174,187,190,189,198

[56] References Cited UNITED STATES PATENTS 1,210,345 12/1916 Miller ..66/198X Buchholz 66/189 X 2,450,376 9/1948 Holmes 66/14 2,506,745 5/1950 Schuesslcr 66/172 X 2,719,416 10/1955 Saunders 66/14 3,184,236 5/1965 Zens 66/170 X FOREIGN PATENTS OR APPLICATIONS 1,229,035 3/1960 France 66/189 2,006,394 12/1969 France 66/9 R 1,804,235 7/1969 Germany 66/187 154,974 5/1965 66/172 R U,S.S.R

Primary ExaminerWm. Carter Reynolds Attorney, Agent, or FirmRoben E. Burns; Emmanuel .l. Lobato [57] ABSTRACT Circular knitting method and machine in which tubular knitted fabric is closed by loop transfer from needle to needle through the remaining loops and locked by knitting, preferably preceded by wale reduction by loop transfer.

16 Claims, 23 Drawing Figures Y PATENTEDAPR 2 I914,

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sum u3 nr12 PATENTEDAPR 2 m4 SHEET 05 HF 12 PATENIED R 21914- SHEET '08 0F 12 PATENTEDAQPRZ m4 sum 09UF12 PATENTEDAPR 2W4 3.800 560 sum 10M 12 SHEET 11 [1F '12 'PATENTEDAPR 2- 914 FTE/E.

PATENTEUAPR 21914 sum 12 HF 12 FIGJB, F|G.I9 HQ 20 1 MACHINE FOR AND METHOD or KNITTING STOCKING WITH CLOSED TOE The invention is for improvements relating to tubular knitted fabric and provides a method of and a machine for constructing a portion of tubular fabric, and more particularly of closing an end thereof.

The invention is especially useful in connection with the formation of toe end parts of tubular knitted arti- I cles of hosiery foot wear, for example socks, stockings, or pantie-hose, and will be described hereinafter in connection therewith.

The invention provides a method of knitting a closed ended tube of fabric in which as a final operation in the knitting sequence knitting is discontinued while the last formed loop in a course of loops is transferred progressively from needle to needle and passed in turn through the remaining loops in the course so as to draw those loops together to form the closure, the loop which is passed through the remaining loops being subsequently locked by the yarn being knitted. The locking of the loop is conveniently effected by knitting a further loop or loops through it and stopping the final loop by passing a severed end of the knitting yarn through it when it is shed from its needle.

.The last loop of the aforesaid course of loops, on being transferred to a succeeding needle, has the loop on that needle passed over it in normal knitting fashion and is then transferred to a following needle and the procedure repeated so that each of the said remaining loops becomes impaled on the last formed loop. Some extension of the last formed loop must be permitted and this-can be arranged by feeding the yarn to the needles by way of a variable take-up device which will allow additional yarn to be .drawn through the feeder for the extension of the loop and subsequently cause it to be withdrawn when a sufficient number of the remaining loops have been released from their needles to enable the loops to be drawn closer together in forming the closure.

Preferably thenumber of wales in the fabric is reduced by loop transfer and thereafter the final operation is carried out as described above. The reduction of the number of wales may be carried out in one or more stages. Spaced needles may have their loops transferred from them to adjacent needles. The remaining loops are shed from their needles and drawn to a closure. The loop drawn through them is locked to fix the fabric in a closed condition.

The number of wales in fabric being knitted may be reduced on a circular opposed cylinder knitting machine having double ended needles transferable from one to the other of the cylinders, by transferring spaced needles from one to the other of the cylinders, acting on their loops with instruments to spread each of them beyond a nearby needle trick, causing each such loop to be taken into the hook of a needle aligned with the nearby trick and released from the first mentioned needle, and moving the latter needle to an inactive position. The knitting of the fabric may be performed with the active needles all operating in one of the cylinders. When a reduction in the number of wales is required, spaced needles are transferred to the other cylinder, and caused to draw elongated loops which in turn are acted on by instruments in the other cylinder to spread each of them across the aforesaid nearby trick opposite a needle in the first mentioned cylinder, which needle is then moved to pick up the spread loop and the needle from which the loop has been spread is then caused to become disengaged from the loop.

A circular knitting machine organized to knit and close tubular fabric by this procedure has spreading instruments on one of the cylinders, means for causing together to a closure, and for locking the yarn against withdrawal through the end loops. The machine may be organized to cause one of the end loops to be passed in turn through each of the other end loops and drawn taut and locked against withdrawal, for example by passing an end of the yarn through it or through a loop knitted through it.

After knitting a welt followed by a leg portion, all the needles are directed to the bottom cylinder if they are not already in that cylinder and then spaced needles, say every fourth, aretransferred up to the top cylinder. All needles having been caused to knit at the main knitting station, the spaced upper cylinder needles are directed to a high level so that they stretch their loops sufficiently to allow spreading instruments to be projected from within the needle circle outwardly through the stretched loops. The instruments are projected successively, so that as the needle cylinders revolve, and as each stretched loop passes a particular position it is penetrated by an associated instrument. In the course of the continued rotation of the cylinders, displacement of the instrument circumferentially of the needle circle relatively to the needle is caused to occur so that one leg of the stretched loop is distended a distance equivalent to a pitch and a half of the needle spacing. At this stage a bottom cylinder needle adjacent to the upper cylinder needle is raised through the distended loop, the upper cylinder needle is lowered until its loop is cleared above the latch, and then raised again to shed the loop and thus complete its transfer to the adjacent needle in the bottom cylinder. At this stage. the spreading instrument is withdrawn.

As this loop transfer action is progressive, it follows that in the course of a single revolution of the needle cylinders the spaced needles will have transferred their loops to adjacent needles and moved upwardly to inactive positions The spaced needles remain out of action in the upper cylinder and knitting continues on the remaining needles for a desired number of courses to make the first portion of the toe fabric with a reduced number of wales. A further reduction in the number ofwales is brought about by repeating the transfer sequence just described, but in this instance the spaced needles which are transferred to the upper cylinder to stretch their loops (for subsequent transfer to adjacent needles) are needles situated at one side of the inactive empty needles.

If one considers that the first portion .of the toe is knitted with every fourth needle inactive in the upper cylinder, then the situation after completing the second transfer is that every fourth needle and a needle 'adja cent to it is inactive in the upper cylinder and the second portion of the toe fabric is therefore knitted on pairs of adjacent needles in the bottom cylinder which are spaced apart by three needles spaces: the gap left by a pair of inactive needles in the top cylinder.

Having knitted a desired number of courses for the second portion of the toe fabric a still further reduction in the number of wales is brought about by repeating the transfer sequence and the situation after completing this third transfer is that the inactive needles in the upper cylinder which have transferred their loops are grouped in threes and each group is spaced from the next by the spaces on each side ofa single active needle remaining in the bottom cylinder. Thus if there were initially a total of, say 84 needles knitting in the machine at the commencement of knitting of toe fabric, this number of needles would be reduced to 21 needles in the bottom cylinder and 63' inactive needles in the top cylinder at the end of the transfer sequence just described. Although a reduction in the number of wales has been produced, the fabric is still attached to needles which are spaced around the bottom needle cylinder and it is therefore necessary to release the fabric loops from these needles and draw the loops together in order to close the fabric tube.

At the completionof the loop transferring sequence, the spaced needles in the bottom cylinder have two loops on their stems: their own loop and the transferred loop. The needle cylinder is revolved just sufficiently to cause the spaced needles to take yarn at the next feeding station and'draw new loops through the double loops which are then cast off. At this stage the spaced needles are directed to a low position where they hold their single loops within their hooks. They are allowed to remain low by withdrawing the upthrow cam or cams to an inactive position. Because the needles in both the top and bottom cylinders are in a withdrawn position a gap is created between the cylinders. Provided that the needles are maintained in the withdrawn position, the cylinders may be revolved without knitting taking place. To control the length of yarn between the feeder and the last needle to have knitted it, there is conveniently employed a yarn take-up similar to that used in knitting by reciprocation. As the cylinders rotate during the closure procedure the yarn will be carried to and fro across and between cylinders due to its attachment to the last needle to have knitted it and it is therefore desirable to pay out and withdraw the yarn sufficiently to maintain it in a taut condition between the feeder and the needle.

During the first rotation of the cylinderswith the bottom cylinder needles in the low inactive track, the last needle to knit is returned to clearing height and then transferred to the top cylinder and the slider which receives it is then directed into a high track, such as the welt track. This action causes the loop around its stem to slide down the stem until it reaches the latch at the lower end of the needle and as the latch is held open by the latchguard it prevents the loop from sliding off the needle. lf normal knitting were taking place the raising of the needle would be liable to cause excessive strain to be imposed on the yarn and on the latch also, but as knitting is not taking place at this stage of the toe closing sequence the pull on the loop merely pulls extra yarn through the feeder without straining the yarn unduly because the yarn constituting one leg of the loop passes through a previous stitch in the fabric and from thence directly to the feeder and the take-up device.

Having stretched this last knitted loop between the needle cylinders it is possible to penetrate it with one of the special spreading instruments previously used in the loop transferring sequence, and laterally displace the instrument sufficiently to distend a leg of the loop (the yarn of which is extending through the fabric to the feeder) beyond an adjacent spaced needle which is in a low position holding its loop. This action will draw more yarn through the feeder. The adjacent low needle is then raised to penetrate the distended loop and also cause its own held loop to be positioned below the latch so that subsequent lowering of the needle will draw the yarn of the distended loop through the old loop. At approximately the same time the needle in the upper cylinder which is holding the distended loop can be caused to release the loop by moving the needle clear of the latchguard so that the latch is closed by the yarn passing over the hook. This needle can then be moved to, and retained with the other needles in, an inactive track.

The important achievement which results from the above action is that the fabric wale terminating with an old and a new loop with the yarn from the new loop extending through the old loop to the feeder has been joined to an adjacent wale by virtue of the new loop being drawn through the final loop of the adjacent wale. The successful achievement of this joining of the wales is made possible by the fact that transfer of the last knitted new loop to each active loop holding needle in turn followed at each transfer by simple knitting motion performed by the needle to which the loop is transferred results in the last knitted new loop being passed in turn through all of the other remaining loops on the needles which are knocked over it. The last knitted new loop can grow longer and become shorter as circumstances require during the closing procedure under the control of the yarn take-up device until the loops are finally drawn together to a closure.

In carrying out the transferring action just described, only one needle at a time is transferred to the upper cylinder to extend its loop on each of a number of successive rotations of the needle cylinders, and penetration of the loop by a special spreading instrument, and its lateral distension and'transfer to an adjacent needle all take place within a single revolution. Thus, in considering again a machine having a total of 84 needles in which 63 are inactive in the top cylinder and 21 needles are spaced around the bottom cylinder holding their loops it would take 21 cylinder rotations to connect the terminal loops together as described and in the process 20 spaced needles will have been transferred to join the other empty needles held inactive in the top cylinders leaving the fabric connected to one needle remaining in the bottom cylinder.

As each of the spaced needles casts off its held loop the wale which has been held by the needle will become held on the two portions of yarn forming sides of the loop which has been passed through the others, and as each successive wale isso released by its associated needle a gradually increasing number of wales will be strung on the joining loop. Whereas initially the wales were hanging from the needles in a circle they will now be hanging in a line forming a gradually increasing chord until half the number of spaced needles have cast off their loops. After half of the needles have cast off their loops the line of hanging wales form a gradually decreasing chord because the yarn in one of the two side portions of the joining loop is gradually drawn back through the feeder by the take-up device and thus the terminal loops of the wales are gathered together in the manner of certain fabric being drawn together by a cord.

The above procedure is continued until only one needle remains active and at this stage the terminal loops of all the other wales have been gathered together by the transferred joining loop which is then on the remaining active needle and has said terminal loops bunched together on its neck. The yarn'forming one side of the joining. loop is connected to the wale which was the first to be cast off and this wale is of course adjacent to the wale of the joining loop, By continuing the rotation of the needle cylinders and at the same time directing the last active needle to pass down the stitch cam as it passes the yarn feeder, a loop is knitted through the'joining loop and holds the aforesaid terminal loops bunched together on the latter. The needle cylinders may be rotated approximately twice more with the last active needle caused toknit with the result that a three course chain of stitches is formed by the yarn. Afte the last passage of the needle down the stitch cam the needle is not raised, the feeder is moved over to its trapper and the yarn is trapped and cut. The knitted article is drawn off through the needle cylinder by a fabric draw-off means and this last action drags the fabric away from the needle from which it is only held by a loop within the hook, one end of which passes through the previous loop and finishes in a severed end. The dragging action causes the severed end to be drawn back through the previously knitted stitch thus necessary with the alternative procedure in which the yarn is held behind the latch. To cast off a transferred loop from such a needle, the needle is transferred into the bottom cylinder in a manner causing the loop to ride off over the latch at the upper end and then be directed to a low inactive level.

Other variations in the procedure may be advantageous, for instance a yarn change may be made just prior to the fabric closure stage so that a stronger yarn can be used for taking the strain of holding the terminal loops of the wales and bringing them to a closure. It could be advantageous also to have the terminal loops themselves formed from the stronger yarn or reinforced by an additional yarn.

The invention is illustrated in the drawings in which:

FIG. 1 is a sectional elevation view of parts of an opposed double cylinder circular knitting machine showing the upper needle cylinder and some of the related parts together with the upper part of the lower needle cylinder and some of its related parts;

FIG. 1a is a plan locating cams, yarn feed finger, and upper latch guard;

FIG. 2 is a perspective view of part of the upper needle cylinder showing a gear drive arrangement associated with the cylinder and also with an inner cylinder which carries loop transferring instruments;

. FIG. 2a is a plan of a second gear train for altering the speeds of the two cylinders;

FIGS. 3 to 5 inclusive illustrate steps taken in transferring a loop through a distance of one pitch;

FIGS. 6 to 15 inclusive show the steps taken at cylinder positions designated F6 to F15 respectively in FIG. 1a in transferring a loop through a distance over four needle pitches in the first stage of securing the terminal loops of the wales; and

FIGS. 16 to 21 show diagrammatically the locking of the last wale.

The machine shown in FIG. 1 has a bottom cylinder assembly comprising a needle cylinder 130, cam box 131, sinker ring and cam assembly 132 and inside sinkers 133. The top needle cylinder 101 is secured to a cylinder gear 102 which is located within a bearing 103 mounted in a housing 104 supported by a plate 105. A drive shaft 106 has a pinion 107 for driving the cylinder gear 102.

Located within the upper needle cylinder is a second cylinder 108 also having slots or tricks cut in its periphery in which are locatedspecial spreading instruments 109. The instruments closely resemble the instru-' ments which are used in a known machine capable of manufacturing terry fabric. They are formed with a widened region 109a midway of their length and about which they can be rocked. At their upper ends they are each provided with a buttlike projection 1091) which locates the instrument heightwise. A part 1096 on each instrument provides a means whereby they are rocked. The bottom ends 109d of the instruments are shaped suitably for penetrating the needle loops when the instruments are rocked to move their lower ends outwardly.

Penetration of a loop by more than one transfer instrument is prevented by means of a well-known selecting device which enables one transfer instrument in four to be selected. The transfer instruments 109 are each lengthened at the upper end 10%. Four selecting devices are placed at different levels, one to each instrument echelon fashion around the cylinder. A selecting cam 116a in the selecting device operates at one of the different levels. FIG. 1a shows at F13 the relative position of the transfer instrument of FIG. 13 to the operating

cams

116 and 115, and the latch guard 144. The bottom end 109d of the transfer instrument 109 projects through a stretched loop at a position F9, when so directed by the nose of a cam 116a of the lever 116. The latch 142 of the upper needle is supported by the upper face 144ofa latch guard, and the loop is fully extended by the transfer instrument 109 which is about to be retracted by the cam 115 after the loop has been placed on the rising needle 134C in the lower cylinder.

A ring 110 surrounding the upper ends of the instruments 109 is supported on a further ring 111 on which are mounted cams such as 112. The ring 111 is itself supported by pillars 113 on a plate 114 to which are attached further cams such as 115 and 116a, the latter of which is part of a bell crank lever 116 and is therefore insertable against the action of a spring 117.

The inner cylinder 108 and the spreading instruments 109 carried by it are capable of bodily rotary movement relatively to, and about the axis of, the needle cylinder for the purpose of spreading loops laterally during the loop transferring sequences.

The inner cylinder 108 is provided with a flange 108a (FIG. 2) which sits upon a gear 118 serving to drive the cylinder 108 through a key 119. The inner cylinder 108 is supported within the needle cylinder 101 by the gear ring-118 and a thrust bearing is provided between the gear ring 118 and the normal cover plate 121 which is secured to and revolves with the needle cylinder. 1

The bottom cylinder 130 is driven from the shaft 106 so that both needle cylinders and 130 turn at the same speed and with their needle tricks in vertical registry. The inner cylinder 108 has fixed to it a gear 118 by whichit is driven independently of the needle cylinders but from the same vertical shaft 106 (FIG. 2) through a pinion 122 which meshes with a gear 123. The gear 123 is one of a train of gears which are mounted as an assembly on a plate 124 pivoted on the vertical drive shaft 106. Co-axial with the gear 123 is a further gear 125 which drives the cylinder gear 118 through anintermediate gear 126; i

The gear train shown in FIG. 2 is designed to cause rotation of the inner cylinder 108 in the same direction as the

needle cylinders

101 and 130 but ata slightly different speed. Thereby it is arranged that the inner cylinder 108 will overtake or alternatively lag behind the needle cylinders for the purpose of causing relative spreading movement along the needle circle between the needles and the instruments 109,.to spread loops laterally. I

The timing of the rotation of the cylinder 108 in relation to the

needle cylinder

101 and 130 and of the loop transferring action for reducing the number of wales prior to closing the fabric tube will now be explained. At the stage where a needle is transferred to the top cylinder and has stretched its loop vertically, it is arranged that instrument 109 shall be positioned on the same radial line as the needle and can be projected by operation of the cam 116a on its part 1096 to penetrate the stretched loop. By the time the needle cylinder has turned through a certain angle, conveniently a quarter of a rotation the inner cylinder 108 by a lagging speed of rotation is arranged to have turned through only a quarter of a rotation minus one and a half needle pitches and the instrument 109 has thus laterally distended'the needle loop rfor penetration by an adjacent needle. This reduction in the number of wales is carried out in one revolution of the needle cylinder and therefore the penetration and lateral distension of each loop takes place progressively as the needles pass in turn through the loop transfer zone.

As the instruments 109 reach a certain point in their circular path which may be termed the loop penetration position each successive instrument must be in alignment with an associated needle and then as the same instruments reach a further position at which loop transfer is arranged to occur, each successive instrument must have moved out of radical alignment with said associated needle to the extent of one and a half needle pitches. This required function of the instruments 109 is achieved by having more instruments in cylinder 108 than there are needles in the needle cylinder and by rotating the instrument cylinder 108 slightly slower than the needle cylinder 101.

Clarification of this may be obtained by considering by way of example a convenient arrangement in which rangement the angular pitch of the instruments is less than the angular pitch of the needles and in order to obtain synchronisation of successive instruments with successive needles as they pass the loop penetration position the gear train must be suitably designed to revolve the instrument'cylinder 108 slightly slower than the needle cylinder, and at a rate such that in one rotation of the instrument cylinder l08.any one needle will have travelled through one rotation plus six needle pitches. In other words each instrument 109 will have a lag of six needle pitches with respect to the needle with which it was associated at the commencement of the rotation. Therefore, if the angular distance from the loop penetration position tothe point of loop transfer is 90, then in this distance an instrument will lag by one and a half needle pitches behind. its associated nee- It is of course necessary to alter the ratio between the speed of the instrument cylinder and'the needle cylinder when performing the loop transferring sequence for final closing of the fabric tube because, in this instance the loop has to be transferred over a distance of more than four needle pitches or from spaced needle to spaced needle as before described. This alteration in the relative speeds of the two cylinders is obtained by a second gear train shown in FIG. 2a which is carried by the plate 124. Such a train of gears comprises the pinion 122 and gears 123a and 126a carried on a second arm of the plate 124 on the opposite side of the drive shaft 107. The plate l24 is biased in a counterclockwise direction by a spring 124a and can be rotated in a clockwisedirection by a control wire-l24b. By partial rotation of'the plate 124 in a counter clockwise direction about shaft 106, the gear train shown in FIG. 2 is brought into mesh to drive the instrument cylinder at a speed suitable for transferring loops to adjacent needles. Alternatively -partial rotation of the plate 124 in a clockwise direction-about shaft 106 the second gear train is brought into mesh for. driving the instrument cylinder at a speed suitable for transferring loops to spaced needles.

-During the final loop transferring sequence only one loop is transferred to an adjacent spaced needle in one revolution of the needle cylinders. However, the function of the instrument cylinder is substantially the same as that just described but in this sequence the instrument cylinder is revolved at a lower speed toenable the transferring instrument to lag in relation to its associated needle by the extra distance needed to transfer to an adjacent spaced needle. v

Although the instruments will be projected successively as they pass the loop penetration position only one will penetrate a loop on each revolution of the needle cylinders because onlyone loop is presented for penetration.

During the final loop transferring sequence and locking of the last loop as described earlier the two needles conceriied in the action i.e., the needle which is transferred to stretch its loop and the needle which is raised to receive the loop, may be selected by patterning mechanism. In addition or alternatively other means may be used such as appropriately controlled bolt cams operating on slider or selector butts of different lengths or at different levels. Modifications may also be made to conventional cam box systems to provide for the re- 9 quired co-operation between the needles and instruments.

The sequence of transferring a loop to an adjacent needle for reducing the number of wales is shown in FIGS. 3 to inclusive. FIG. 3 shows needles 134 in the bottom cylinder 130 and a needle 135 which has been transferred to the top cylinder and has formed a loop 136 in its bottom hook and extended the loop vertically, the needle 135 having reached the loop penetration position. The end 109d of the related instrument 109 is moved out to penetrate the loop at this point by the cam 116a (FIG. .1) bearing on the part 1090 of the instrument 109 (the cam 115 not bearing on the opposite side of the instrument at the time). After the cylinders have turned approximately throubh 90 (FIG. 4), the loop 136 is spread for engagement by the next bottom cylinder needle 134a which is raised to receive it without clearing its previous loop and then lowered (FIG. 5), the needle 135 in the upper cylinder 101 being also lowered to clear the spread loop 136 and afterwards raised to cast-off the loop 136 and move the needle 135 to an inactive position. At the next yarn feeding station, the two loops on needle 134a are together knocked over the newly fed yarn. This procedure is repeated to reduce the number of wales and leave the mechanism as in FIG. 6 discussed below.

The sequence of transferring a loop to an adjacent spaced needle is shown FIGS. 6 to 15. Spaced active needles 1341; in the bottom cylinder 130 have three empty tricks 138 between each and the next. A last formed new loop indicated 143 is in the top hook of the needle 134k (on the right of FIG. 6) and is a direct continuation from a length of yarn 146 supplied by a feeder (not shown) associated with a yieldable yarn take up device (not shown). The bars of yarn between preceding loops of the same course are seen at 145 extending over sinkers 137. In FIG. 6 the right hand needle 134b carried on its bottom slider 140 is about to be transferred to the top cylinder and during its upward movement (FIG. 7) the loop 143 clears the needles upper latch 141 as the needle approaches its top slider 139. Then, as seen in FIG. 8, the needle leaves its bottom slider as in a normal transfer action and becomes engaged with its top slider 139, while the .loop 143 becomes caught behind (i.e., above) the'needles open bottom latch 142. The latter is held open by an upper latchguard the level of the top edge of which is indicated by a broken line 144 in FIGS. 9 to 14. In its upwardly transferred position the needle is indicated at 135a and it is raised still further (FIG. 9) by its top slider to lengthen the loop 143 by drawing yarn through the feeder. At this stage the end 109d of the related instrument 109 actuated by the cam 116 engages in the lengthened loop and during subsequent turning of the cylinders the lagging motion of the instrument cylinder causes the loop 143 to be widened at 143a (FIGS: 10, 11 and 12) whilst the bottom latch 142 stays half open resting on the top edge 144 of the latch guard and thus retains the loop.

The widened loop 143a is fully spread by the instrument 109 in the position of FIG. 13 and is being received by the next spaced needle l34b which is raised as indicated at 1340 to receive the spread loop 143a above its top latch 141 whilst the loop 147 already on it (being one in the same course as loop 143a) is cleared below the latch 141. The end 109d of instrument 109 is then withdrawn by the action of cam 115 and receiving needle 1340 caused to knit (FIG. 14)

whilst the bottom latch 142 of needle a moves off and when required) has been passed through all other loops on the needles and cast off from each preceding needles in turn, the'yarn take'up device'drawing the loops together on the neck of the extended loop 143a.

Although expanded and contracted a number of times,

the loop 143a is not unduly damaged because during expansion yarn is drawn from the supply through a take up mechanism, and during contraction the take up mechanism draws back the surplus yarn to tighten up the loop again after it has been transferred. At this stage the garment is attached to the machine by a single needle as shown in FIG. 16. Knitting then takes place on the last needle (FIG. 17) forming a chain of stitches shown diagrammatically in enlarged view in FIG. 18.

FIG. 19 shows diagrammatically the yarn having been severed at 148 and in course of being drawn through the last knitted stitch, and FIG. 20 shows similarly the later stage in which it is drawn out of the needle hook.

FIG. 21 shows in perspective view how withdrawal of the garment by the fabric air suction draw-off means generally used on such machines is utilized to draw the severed yarn end through the last stitch.

What we claim is:

1. A method of knitting a closed ended tube of fabric on a circular knitting machine having superposed needle cylinders, needles operable in said cylinders, and yarn feeding means, comprising the steps of knitting a plurality of courses of loops of yarn, transferring the lastformed loop in a course of loops from the needle by which it is drawn successively to other needles having previously formed loops thereon and successively operating said other needles to draw said last formed loop successively through said previously formed loops, whereby said last formed loop is passed in turn through all of the remaining loops in the course, tensioning the yarn of said last formed loop to draw said remaining loops together to form a closure and subsequently locking said last formed loop to secure said closure.

2. A method according to claim 1 in which said last formed loop is locked by knitting at least one further loop through it and stopping the final loop by drawing a severed end of the knitting yarn through it when it is shed from its needle.

3. A method of knitting a closed ended tube of fabric on a circular knitting machine having superposed cylinders, needles operable in said cylinders and yarn feeding means, comprising the steps of knitting a plurality of circular courses of loops of yarn, transferring loops of yarn from spaced needles to intervening needles to reduce the number of wales in the fabric by loop transfer and accordingly reduce the number of active needles, knitting at least one course on the reduced number of needles, and thereafter transferring the last formed loop in the last course of loops from the needle by which it is drawn successively to other active needles having previously formed loops thereon and suc- 1 1 cessively operating said last mentioned needles to draw said last formed loop successively through said previousy formed loops, whereby said last formed loop is parallel in turn through all of the remaining loops in the course, tensioning the yarn of said last formed loop to draw said remaining loops together to form a closure and subsequently locking said last formed loop to secure said closure.

4. A method according to claim 3 in which the reduction in the number of wales is carried out in two stages.

5. A method according to claim 3 in which the reduction in the number of wales is carried out in three stages.

6. A method according to claim 3, in which said last formed loop is locked by drawing at least one further loop of the same yarn through it, severing said yarn and drawing the severed end of the yarn through the final loop.

7. A method according to claim 3, in which said last formed loop is transferred by expanding one side of said loop laterally sufficiently to be taken in the hook of an adjacent active needle, releasing said last formed loop from the needle by which it was drawn and actuatingsaid adjacent active needle to draw said last formed loop through a previously formed loop on said adjacent needle.

8. A method of knitting a closed ended tube of fabric on a circular knitting machine having superposed cylinders with aligned tricks, needles operable in said tricks and transferable from one cylinder to the other and yarn feeding means, comprising the steps of knitting at least one course with the active needles all operating in one of the cylinders, discontinuing knitting while spaced needles are transferred to the other cylinder and are operated to draw elongated loops, engaging said loops by instruments in said other cylinder to spread each of them laterally sufficiently to be opposite a needle in said one cylinder, operating said last mentioned needle to pick up said spread loop, and disengaging said transferred needle from said loop whereby the loops of said spaced transferred needles are transferred to interveining needles to reduce the number of wales and accordingly reduce the number of active needles, knitting at least one course of loops on the reduced number of needles, transferring the last formed loop in a course of loops from the needle by which it is drawn successively to other needles having previously formed loops thereon and successively operating said other needles to draw said last formed loop successively through said previously formed loops, whereby said last formed loop is passed in turn through all of the remaining loops in the course, tensioning the yarm of said last formed loop to draw said remaining loops together to form a closure and subsequently locking said last formed loop to secure said closure.

9. A method according to claim 8, in which the needle by which said last formed loop is drawn is transferred to said other cylinder and said loop is transferred successively to said other needles by being spread laterally to be taken successively by said other needles which are then operated to draw said last formed loop successively through the previously formed loops on said other needles.

10. A method according to claim 9, in which said last formed loop is transferred and drawn through one of said previously formed loops in each revolution of the machine.

11. A method according to claim 8, in which said last formed loop is locked by drawing at least one further loop of the same yarn through it, severing said yarn and drawing the severed end of the yarn through the final loop.

12. A method according to claim 11, in which said machine has fabric take-off means and in which said severed end of yarn is drawn through the final loop by drawing said fabric off by said take-off means while holding said yarn on the hook of the needle forming said final loop.

13. In a circular knitting machine having coaxial needle cylinders with aligned tricks, needles operable in said tricks and transferable from one cylinder to the other and yarn feeding means, cam means for operating said needles to take yarn from said yarn feeding means and to knit said yarn to form tubular fabric and for transferring from one cylinder to the other selected spaced needles from which loops are to be transferred, spreading instruments on said other cylinder, means for selectively operating said spreading instruments to pick up loops of yarn on said transferred needles and spread them circumferentially of the needle cylinders, cam means for operating intervening needles remaining in said one cylinder to receive said spread loops and thereby transfer said loops to said intervening needles to reduce the number of wales, means for selectively operating said needles and spreading instruments to draw the last formed loop of a course of loops successively through the remaining loops of said course, and means for tensioning the yarn of said last formed loop to draw said remaining loops together to form a closure of said tubular fabric.

14. A circular knitting machine according to claim 13, comprising means for operating a needle on which said last formed loop remains after being drawn through all of said remaining loops to draw at least one further loop and to lock the final loop to secure said closure.

15. A circular knitting machine according to claim 13, in which said spreading instruments are retractably carried on a cylinder coaxial with said other cylinder and separately driven to rotate with a speed differential with respect to said other cylinder.

16. A circular knitting machine according to claim 15, comprising means for selectively varying the speed differential between said other cylinder and said cylinder carrying said spreading instruments.

Claims

1. A method of knitting a closed ended tube of fabric on a circular knitting machine having superposed needle cylinders, needles operable in said cylinders, and yarn feeding means, comprising the steps of knitting a plurality of courses of loops of yarn, transferring the last formed loop in a course of loops from the needle by which it is drawn successively to other needles having previously formed loops thereon and successively operating said other needles to draw said last formed loop successively through said previously formed loops, whereby said last formed loop is passed in turn through all of the remaining loops in the course, tensioning the yarn of said last formed loop to draw said remaining loops together to form a closure and subsequently locking said last formed loop to secure said closure.

3. A method of knitting a closed ended tube of fabric on a circular knitting machine having superposed cylinders, needles operable in said cylinders and yarn feeding means, comprising the steps of knitting a plurality of circular courses of loops of yarn, transferring loops of yarn from spaced needles to intervening neEdles to reduce the number of wales in the fabric by loop transfer and accordingly reduce the number of active needles, knitting at least one course on the reduced number of needles, and thereafter transferring the last formed loop in the last course of loops from the needle by which it is drawn successively to other active needles having previously formed loops thereon and successively operating said last mentioned needles to draw said last formed loop successively through said previousy formed loops, whereby said last formed loop is parallel in turn through all of the remaining loops in the course, tensioning the yarn of said last formed loop to draw said remaining loops together to form a closure and subsequently locking said last formed loop to secure said closure.

7. A method according to claim 3, in which said last formed loop is transferred by expanding one side of said loop laterally sufficiently to be taken in the hook of an adjacent active needle, releasing said last formed loop from the needle by which it was drawn and actuating said adjacent active needle to draw said last formed loop through a previously formed loop on said adjacent needle.