US2723544A - Method of and means for producing circular knitted fabric and articles - Google Patents

Description

Nov- 15. 1955 E. OVERFlELD-COLLINS ETAL 2,723,544

METHOD OF AND MEANS FOR PRODUCING CIRCULAR KNITTED FABRIC AND ARTICLES Filed Jan. 25, 1955 5 Sheets-Sheet 1 A [torn e ys Nov. 15. 1955 E OVERFIELD-COLLINS ETAL 2,723,544

METHOD OF AND MEANS FOR PRODUCING CIRCULAR KNITTED FABRIC AND ARTICLES Filed Jan. 25, 1955 5 Sheets-Sheet 2 I g NM NQ mia Q N Inventors Eon/I070 01 599540 w44//v s,

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Nov. 15, 1955 E. OVERFlELD-COLLINS ETAL METHOD OF AND MEANS FOR PRODUCING CIRCULAR KNITTED FABRIC AND ARTICLES 5 Sheets-Sheet 3 Filed Jan. 25, 1955 A ttorneys! Nov- 1 1955 E. OVERFIELD-COLLINS ETAL 2,723,544

METHOD OF AND MEANS FOR PRODUCING CIRCULAR KNITTED FABRIC AND ARTICLES Filed Jan. 25, 1955 5 Sheets-Sheet 4 A ttorneys Nov. 15. 1 55 E. OVERFIELDCOLLINS ET L 2,723,544

METHOD OF AND MEANS FOR PRODUCING CIRCULAR KNITTED FABRIC AND ARTICLES 5 Sheets-Sheet 5 Filed Jan. 25, 1955 United States Patent METHOD OF AND MEANS FOR PRQDUCING CIR- CULAR KNITTED FABRIC AND ARTICLES Edward Overfield-Collins, Beckenham,.and Alfred Percy Saunders, Leicester, England, assignors to Wildt and Company Limited, Leicester, England, a British com- P y Application January 25, 1955, Serial No. 485,968

Claims priority, application Great Britain February 1, W54- 12 Claims. (Cl. tie-24) This invention relates to a simple method of and means for producing in weft knitted fabric, on a circular knitting machine by rotary, in contradistinction to reciprocatory, knitting improved isolated designs akin to or simulating those known as intarsia." Circular weft knitted fabrics and articles patterned .by such designs are the subject of our co-pending application No. 483,967, filed January 25, 1955.

The method according to this invention of producing such isolated intarsia designs on a circular knitting machine involves a two-part cycle carried out at two succeeding stations of which the first is a non-knitting station whereat ground yarn only is fed in, whilst the second is a knitting station at which a patterning yarn only :is fed. Broadly considered, this method may conveniently include the steps of (a) selecting desired needles to avoid taking the ground yarn at the first station, (b) causing non-selected needles at this station to receive the ground yarn into their hooks and thereupon moving the said non-selected needles to a non-knocking over position so that the ground yarn tunnels through .the hooks thereof and is not knitted thereby, .(c) at the second station causing those needles previously selected to miss the ground yarn to take and knit the patterning yarn only, and (d) also at the second station selectively advancing previously non-selected needles having ground yarn in their hooks to a non-clearing level thereby enabling them to take the patterning yarn, and then moving these non-selected needles to knocking-over position so that they knit both yarns.

Naturally, any non-selected needles which are not advanced to receive patterning yarn at the second station knit the ground yarn only.

At each successivecourse during the production of an isolated design the patterning yarn is trapped and cut or floated after being knitted together with the ground yarn.

The circular knitting machine for carrying out this method may be either of the type including a plain needle cylinder only, or a ,rib knitting machine furnished with a second needle bed for rib needles. In the latter case, the desired rib needles which are to co-operate-with plain needles in the production of rib knitted fabric are suitably advanced at the non-knitting station (as are also the said plain needles) to receive the ground yarn into their hooks, and are then retracted to a non-knockingover position so that the ground yarn merely tunnels through these hooks and also the hooks of the co-operating plain needles without 'being knitted; at the knitting station both the rib needles and the plain needles are retracted to their respectve knocking-over positions so that they knit the ground yarn.

A circular rib knitting machine constructed in accordance with this invention is essentially equipped with means whereby loops can be transferred from rib needles to plain needles. Thus, a transfer of loops from rib needles to plain needles would take place after the completion of a portion of rib knitting and preparatory to the production of an adjoining portion of plain knitted fabric incorporating the isolated designs. At such a time, moreover, the rib needles are retracted to an inoperative position and are maintained inactive throughout the knitting of plain fabric.

In order that the invention may be more clearly understood and readily carried into practical effect, specific examples of circular knitting machines capable of carrying out the hereinbefore described methods of producing fabrics and articles patterned with isolated intarsia designs will now be described with reference to the accompanying drawings, wherein,

Figure l is a vertical sectional view taken through the head of a circular knitting machine constructed to produce plain knitted fabric incorporating isolated intarsia designs,

Figure 2 is a purely diagrammatic development of the cam system of such machine, showing a few of the needles and needle-actuating jacks, and the needle selecting means at the non-knitting and knitting stations,

Figure 3 is a similar diagrammatic development of the cyinder and rib dial cam systems of a circular rib knitting machine adapted to produce rib knitting in addition to plain knitting patterned by isolated intarsia designs, the said dial cam system, for the sake of clarity, being shown separated from and in the same plane as the cylinder cam system,

Figure 4 is a fragmentary perspective view illustrating a few of the cylinder and dial needles of this rib knitting machine in the course of receiving the ground yarn in their hooks at the non-knitting station,

Figure 5 is a fragmentary vertical sectional view taken through the cylinder and the dial of the said machine and shows more clearly the manner in which the ground yarn tunnels through the hooks of the cylinder and dial needles as the latter move from the non-knitting station towards the knitting station,

Figure 6 is another fragmentary perspective view illustrating cylinder and dial needles knocking-over at the knitting station to produce rib fabric,

Figure 7 is a detail perspective view illustrating the intarsia yarn trapping and cutting device, and

Figures 8 and 9 are detail plan and front elevational views respectively of the operating connections for the movable trapper and cutter'blades and the means whereby these connections are controlled.

Like parts are designated by similar reference character-s throughout the drawings.

A plain circular knitting machine constructed in accordance with this invention and capable of carrying out the hereinbefore described cycle will now be described with the aid of Figures 1 and 2. As will be seen from Figure 1, the machine includes .a rotary needle cylinder '15 which is equipped with latch needles such as 16, and surrounded by a relatively stationary annular cam box 17. This box is mounted upon a fixed carriage 18. Each vneedle 16 is furnished with a butt 16a adapted to be acted upon by appropriate cams in the cam box 17, and is arranged to be selectively advanced at required times by an associated jack 19 having a forwardly projecting shoulder 19a for engagement with the lower extremity 16b of the needle. The jacks 19 are of the kind having inherently springy lower end portions 19b which are normally outwardly inclined with their feet 190 held forward and in the path of jack raising cams, but are adapted to be selectively pressed inwardly against the spring action by means of selective manipulation of pattern controlled pivoted pressers 20, for the purpose of moving the said feet back clear of the jack raising cams at appropriate times. The pressers 20 are formed, in known manner, with butts 20a disposed in respectively different planes for engagement by relevant ones of a bank of pattern levers 21 in turn arranged to be selectively operated by an intermittently rotatable pattern wheel or drum, such as 22 (Figure 1), furnished with pre-arranged bits, pins or projections (not shown). The needle selecting means may, however, be of any other appropriate type.

For the purpose of the present invention the machine includes:

(1) A non-knitting station U at which are provided a guide 23 for feeding a ground yarn 2 to appropriate needles 16, a normal or low level clearing cam 24, an adjacently located cam 25 for retracting those needles advanced by the said clearing cam 24 to a non-knocking over (tunnelling) position W, a dividing cam 26 coincident with but at a more advanced level than the normal clearing cam 24, the said dividing earn also functioning after the manner of a high level clearing cam, a needle selecting unit X (including a pattern wheel or drum 22 and associated bank of pattern levers 21) for selecting desired needles for engagement with the dividing cam 26 whereby they are sufficiently advanced to the level Y to avoid taking the ground yarn 2, and a cam 27 for retracting the said selected needles to a level Z at which they are enabled subsequently to receive intarsia yarn fed thereto, and

(2) A knitting station V at which are provided a guide 28 for feeding in an intarsia yarn 5, a needle selecting unit X similar to the unit X for selecting desired ones of the needles 16 having ground yarn in their hooks and advancing the same to a level Z at which they will also take the intarsia yarn 5, and a stitch forming and knocking-over cam 29.

At or adjacent to the knitting station V there may advantageously be provided a latch opener 30 and an associated latch retainer 31 and latch guard 32 adapted to ensure that the latches 16b of those needles 16 selected at the non-knitting station U are open and guarded at the time they are to receive the intarsia yarn 5.

In conjunction with the needle-selecting unit X at the non-knitting station U there is provided a jack-raising cam 33 for advancing selected jacks 19 and corresponding needles 16 to such a height as to land the butts 16a of those needles onto the dividing cam 26. Similarly, there is provided in conjunction with the needle-selecting unit X at the knitting station V a jack-raising cam 34 for advancing selected jacks to such a height as to position the hooks of the corresponding needles, such as that designated 16", at the level Z aforesaid.

Also provided in the cam box 17, immediately in advance of the non-knitting station U, is a depress cam 35 for action on the butts 16a of all the needles for the purpose of retracting the latter to an initially low position prior to selection. Guard cams 36 and 37 are provided at the station U. In advance of the stitch cam 29 at the knitting station V there is provided a guard cam 38 and, immediately beneath the latter, a pivoted clearing cam 39 adapted, as occasion demands, to be turned down (as shown) into an inoperative position.

It is to be clearly understood that the needle-selecting units X and X at the two stations require to be synchronised and to have related lay-outs of bits, pins or projections.

If desired, the machine may also be equipped with yarn changing means (see the additional guides 40, 41 and 42) whereby an intarsia yarn of one colour can be substituted for another of a different colour, according to patterning requirements.

The invention is primarily intended for application to circular knitting machines equipped with latch needles, and may be applied both to such machines having a rotary cam box as well as to machines of the rotary needle cylinder type.

The manner in which an isolated intarsia design is produced on the circular latch needle knitting machine herein described with reference to Figures 1 and 2 is as follows:

Consider first the knitting of both yarns 2 and 5 together at appropriate points within the area of a design for the purpose of locking into the fabric or article being produced the non-continuous portions of the intarsia yarn 5. At the first, i. e. non-knitting, station U the nonselected needles are raised by the normal or low level clearing cam 24 to such a height Y (Figure 2) that old loops (from the previous course) thereon open and are cleared from latches 16b of the said needles, and the latter take ground yarn 2 into their hooks. All of the nonselected needles are thereupon retracted by the cam 25 to tunnelling level W as a consequence of which the old loops ol close the latches but are not knocked over. The closed latches 16b accordingly retain the ground yarn 2 in the hooks of the non-selected needles such as those indicated at 16", so that the yarn merely tunnels through these hooks. The predetermined ones of the non-selected needles which are to knit both yarns 2 and 5 are then selectively raised by the patterning unit X at the knitting station V to the height Z so that although the tunnelling ground yarn 2 opens the latches 16b of these needles it nevertheless remains in front of, i. e. over, the said latches, whereas the old loops are located behind the same. At the level Z the needles thereby selected at the knitting station V take the intarsia yarn 5 so that as and when the said needles are retracted by the stitch drawing and knocking-over cam 29 at this station, locking loops of both yarns are drawn through the old loops which are knocked over. Such locking loops of both yarns are shown on the extreme right hand needle in Figure 2.

The needles 16' which are to knit the intarsia yarn 5 only within an isolated design are selected by the patterning unit X at the non-knitting station U for engage ment by the dividing cam 26. As a result, old loops are cleared from the latches of the selected needles 16 and the latter are raised to the height Y to miss the ground yarn 2. The selected needles 16' are then retracted by the depression cam 27 to the level Z at which they can take the intarsia yarn 5 at the knitting station V. As the selected needles 16 arrive at this level Z (which is slightly higher than the level Z to which predetermined ones of the initially non-selected needles are raised to receive intarsia yarn as aforesaid) both the old loops thereon and the tunnelling ground yarn 2 are under the needle latches 16b: consequently, as and when the selected needles 16 are retracted by the stitch drawing and knocking-over cam 29 at the knitting station knitted loops of the intarsia yarn are drawn through the old loops and the latter are knocked over together with an unknitted portion of the ground yarn 2.

Of the non-selected needles 16" which take the ground yarn 2 at the non-knitting station U, those which are not subsequently raised to take the intarsia yarn 5 at the knitting station V remain at tunnelling level and are caused to knit the ground yarn only at the stitch drawing and knocking-over cam 29.

As previously mentioned, the required intarsia yarn may be introduced by one of a plurality of selectively operable guides included in yarn feeding means of the cylinder needle stripper type. In any event, there is provided, in conjunction with the intarsia yarn feeding guide or guides, a yarn trapping and cutting device such as that indicated generally at 43 in Figure 7. This device is located within the needle circle, the top of the needle cylinder being indicated by the line 44. When being introduced to the cylinder needles 16, the intarsia yarn 5 extends from the guide 28 (which is in its feeding position) into the trapper and is laid transversely across the path of said needles so that it can be taken by the needles selected to receive it. In Figure 7, the advanced cylinder needle with the open latch 16b is the first selected needle to take the yarn 5. The trapped end of the latter is thereupon pulled out of the trapper, and normal feeding of the said yarn continues until the isolated intarsia design (or at least the portion thereof incorporating the yarn'S) is completed. Thereupon the guide 28 is raised to the dotted position to withdraw the yarn 5 as a consequence of which the latter is drawn into the device 43, trapped and cut. The device 43 is, of course, also used for cutting and trapping the intarsia yarn during the production of a design, that is to say course by course and where the yarn is not required to be floated. As will be seen the device 43 comprises a small block 45 beneath which are mounted a fixed trapper element 46 and a fixed cutter member 47. The member 47 is, however, separable from the trapper element 46, against spring action, but is adapted to move into contact with the said element under this action whenever permitted so to do. Pivotally mounted beneath the block 45, one at each side of the trapper element 46, are a movable trapper blade 48 and a similarly movable cutter blade 49. The said two blades, which are movable together, are connected by means of a link 50, with an operating lever 51 (see Figures 8 and 9). Projecting up from this operating lever is a pin 52 arranged to co-operate with a pivoted spring-influenced catch 53. Normally, the catch 53 is engaged with the pin 52 for the purpose of holding the movable trapper and cutter blades 48 and 49 in the open position shown in Figure 7. By effecting release of the catch 53, however, the operating lever 51 is freed to pull the link 50 and thereby close the blades 43 and 49 suchwise as to cut and trap the intarsia yarn 5. As the said blades 48 and 49 close they become interleaved with the fixed trapper element 46 and the associated fixed cutter member 47. That is to' say, the trapper blade 48 is forcibly inserted between the trapper element 46 and the cutter member 47, whilst the cutter blade 49 engages beneath the element 46. As a consequence the intarsia yarn becomes crimped and thereby adequately held between the various members. By means of this arrangement, the intarsia yarn can be readily cut out at each course during patterning. Before the yarn is cut in this way, however, the guide 28 is raised into the dotted position temporarily to withdraw the yarn from knitting.

The catch 53 is released at the or each appropriate time during each course of knitting by means of a selected one of a series of striker elements 54 arranged at respectively different positions as depicted in Figures 8 and 9. As will be seen, these elements 54 are slidable vertically in a carrier block 55 and are selectively projected for action on the catch 53 from a control chain or the like (not shown) through suitable intermediate connections. The projected position of one of the striker elements 54 is indicated in chain lines in Figure 9. By this arrangement, therefore, the intarsia yarn can always be cut short adjacent to the cutting-out side of an isolated intarsia design thereby advoiding long ends.

To enable a circular knitting machine such as that already described to knit rib fabric, it is equipped with a needle dial and an associated dial cam cap carrying the cams of the dial cam system. This system, and a few of'the dial needles, 56, are represented in purely diagrammatic fashion in Figure 3 to which reference will now be made. Each of the dial needles 56. accommodated in the dial (not shown) is of the transfer type disclosed in the specification of our prior United Kingdom Letters Patent No. 520,417. That is to say, each such needle is provided, as illustrated in Figure 5 with a loop-engaging shoulder 56a and at one side with a recess 56b designed to receive the head of a rising cylinder needle. The transfer dial needles are also adapted for engagement with cam means whereby they are deflected laterally to open out engaged loops and so facilitate transference of the same to cylinder needles. The needles 56, moreover, are furnished with operating butts 56c.

The dial cam system depicted in Figure 3 includes a latch opening cam 57, a latch opener cam guard 58, a combined latch opening point and latch guard 59, a pivoted dial needle advancing cam 60 which is movable either into a clearing position shown in full lines or into an inoperative (chain-line) position, a dial needle retracting cam 61, a retaining cam 62 for determining the position of the dial needles 56 when a ground yarn 2 is tunnelling through the hooks thereof as will be hereinafter described, a stitch and knocking-over cam 63, a withdrawable transfer cam 64 of the bolt type, and a transfer guard cam 65. In this system there is also provided a rest cam 66.

The cylinder cam system illustrated in Figure 3 includes, in addition to the various cams already described with reference to Figure 2, a cam 67 for raising cylinder needles to such a height as to enable them to receive loops from dial needles, during transfer, a depress cam 68 and a rest cam 69.

At every revolution of the machine, all of the dial needles 56 are advanced seriatim by the cam 57 to bring their latches 56d into contact with the latch opener 59. After opening of the latches in this way, all of the dial needles are immediately retracted by the cam 58 to the non-knitting track 70. For rib knitting, the cam 60 is moved into the clearing position, so that after being retracted as aforesaid, the dial needles are then advanced to the position 71 to take ground yarn 2 fed in by the guide 23 at the non-knitting station U. As shown in Figure 4, dial needles 56 successively advanced by the cam6tl project between cylinder needles 16. The three dial needles at the right-hand side of Figure 4 are inactive, not yet having been advanced by the cam 60. After taking the ground yarn 2, the dial needles pass through the non-knitting station U and are then partially retracted, by engagement of their butts 560 with the retracting cam 61, to the position 72 which corresponds with the level W to which the co-operating cylinder needles are withdrawn. This brings the hooks of the dial needles into register with the hooks of the cylinder needles, in the manner clearly shown in Figure 5, thereby providing a free passage therethrough for the tunnelling ground yarn 2. The cylinder and dial needles now move on to the knitting station V, at which a previously feeding intarsia yarn has already been cut-out and trapped, and selection of cylinder needles by the selecting unit X has been discontinued. At this stage, the function of the knitting station V is, therefore, simply to draw the tunnelling yarn 2 (retained in the needle hooks) into plain and rib stitches and to knock-over, these operations being effected by the relatively opposite cylinder and dial stitch earns 29 and 63 respectively. Figure 6 shows the yarn 2 being knitted and knocked-over in this way, a plain loop being indicated at pl and a rib loop at rl.

Whenever a rib knitted portion or area of fabric has been completed and it is desired to resume the knitting of plain fabric, the dial transfer cam 64 is put into operation to advance the dial needles 56 to the transfer position 73, while the cylinder needles 16 are raised by 7 the cam 67 to receive knitted loops from the dial needles. Then, the dial needles from which loops have been transferred are retracted by the cam 65, and the cams 60 and 64 are rendered inoperative to enable the said dial needles to remain inactive in the non-knitting track 70 throughout the knitting of plain fabric.

We claim:

1. A method of knitting including producing an isolated intarsia design within a structure of plain loops on a circular knitting machine which method involves a two-part cycle and includes the steps of (a) selecting desired needles to avoid taking ground yarn fed in at a non-knitting station, (12) causing non-selected needles at this station to receive the said ground yarn into their hooks and thereupon moving the said non-selected needles to a non-knocking over position so that the ground yarn merely tunnels through the hooks thereof without being knitted thereby, (c) at a succeeding knitting station whereat a patterning (intarsia) yarn only is fed causing those needles previously selected to miss the ground yarn to take and knit the intarsia yarn only, and (d) also at the knitting station selectively advancing previously non-selected needles having ground yarn in their hooks to a non-clearing level thereby enabling them to take the intarsia yarn and then moving these previously non-selected but now selectively advanced needles to knocking-over position so that they knit both yarns, the remainder of the non-selected needles not advanced to receive intarsia yarn knitting the ground yarn only at the said knitting station.

2. A method of producing an isolated intarsia design according to claim 1, wherein at each successive course during the production of the design the intarsia yarn is trapped and cut after being knitted together with the ground yarn.

3. A method according to claim 1 wherein the knitting machine is a rib knitting machine and the method includes producing rib fabric by advancing cooperating plain and rib needles to their respective clearing positions and so causing them to take ground yarn into their hooks at the non-knitting station and thereupon retracting the said plain and rib needles at this station to corresponding non-knocking over positions so that the ground yarn tunnels through the hooks thereof and is not knitted thereby, and at the knitting station moving the plain and rib needles to their respective knockingover positions so that they knit the ground yarn into rib fabric.

4. A method according to claim 3 wherein the knitting machine is a patterned, plain fabric knitting machine and the method includes transferring knitted loops from the rib needles to the plain needles, and then retracting the said rib needles to and maintaining them in a nonknitting position.

5. A circular knitting machine comprising, in combination, a cylinder, individually operable needles operating in said cylinder, means at a non-knitting station feeding in a ground yarn, a clearing cam advancing desired needles to take said ground yarn, a retracting cam located adjacent to the clearing cam whereby those needles advanced by the latter are retracted to a nonknocking over (tunnelling) position, a dividing cam coincident with but at a more advanced level than the clearing cam, means selecting desired needles for engagement with the dividing cam whereby they are sufficiently advanced to clear their loops and at the same time avoid taking the ground yarn at the non-knitting station, means feeding in an intarsia yarn at a knitting station succeeding the non-knitting station, a cam retracting said selected needles to a level at which they are enabled to receive the intarsia yarn, means selecting desired ones of the needles which have taken the ground yarn and advancing such needles to a level at which they will also take the intarsia yarn at the knitting station, and, at said knitting station, a stitch forming and knocking-over cam.

6. A circular knitting machine according to claim 5, which includes a yarn trapping and cutting device located within the needle circle and operable during patterning to cut and trap the intarsia yarn course by course at various points coursewise selected to eifect short cutting of the yarn and so avoid the presence of long ends.

7. A circular knitting machine according to claim 5, wherein the needle selecting means at the non-knitting station and also at the knitting station include an intermittently rotatable unit furnished with pre-arranged patterning formations selectively actuating the needles, the said units at the two stations being synchronised and having lay-outs of patterning formations so related as to produce, in each of a plurality of courses of knitting, knitted loops of the intarsia yarn only and knitted loops of both the intarsia yarn and the ground yarn.

8. A circular knitting machine according to claim 5, which is equipped with yarn changing means whereby an intarsia yarn of one colour can be substituted for another of a different colour, according to patterning requirements.

9. A circular knitting machine comprising, in combination, a cylinder, individually operable latch needles operating in said cylinder, means at a non-knitting station feeding in a ground yarn, a clearing cam advancing desired needles to take said ground yarn, a retracting cam located adjacent to the clearing cam whereby those needles advanced by the latter are retracted to a non-knocking over (tunnelling) position, a dividing cam coincident with but at a more advanced level than the clearing cam, means selecting desired needles for engagement with the dividing cam whereby they are sufficiently advanced to clear their loops and at the same time avoid taking the ground yarn at the non-knitting station, means feeding in an intarsia yarn at a knitting station succeeding the non-knitting station, a cam retracting said selected needles to a level at which they are enabled to receive the intarsia yarn, means selecting desired ones of the needles which have taken the ground yarn and advancing such needles to a level at which they will also take the intarsia yarn at the knitting station, a stitch forming and knocking-over cam at the knitting station, and, adjacent to the latter, a latch opener and an associated latch retainer and latch guard adapted to ensure that the latches of those needles selected at the non-knitting station are open and guarded at the time they are to receive the intarsia yarn.

10. A circular rib knitting machine comprising, in combination, a cylinder, individually operable needles operating in said cylinder, a further needle bed, rib needles operable in said bed in co-operation with the cylinder needles, means at a non-knitting station feeding in a ground yarn, a clearing cam advancing desired cylinder needles to take said ground yarn, a retracting cam located adjacent tao the clearing cam whereby those cylinder needles advanced by the latter and retracted to a nonknocking over (tunnelling) position, a dividing cam coincident with but at a more advanced level than the clearing cam, means selecting desired cylinder needles for engagement with the dividing cam whereby they are sufficiently advanced to clear their loops and at the same time avoid taking the ground yarn at the non-knitting station, means feeding in an intarsia yarn at a knitting station succeeding the non-knitting station, a cam retracting said selected cylinder needles to a level at which they are enabled to receive the intarsia yarn, means selecting desired ones of the cylinder needles which have taken the ground yarn and advancing such needles to a level at which they will also take the intarsia yarn at the knitting station, a cylinder stitch forming and knocking-over cam at the knitting station, and a rib cam system including a movable cam adapted when rendered operative to project rib needles between cylinder needles and cause said rib needles to clear and take ground yarn at the non-knitting station, a cam thereupon retracting the rib needles to a non knocking-over position so that the ground 9 yarn merely tunnels through their hooks (and also through the hooks of the correspondingly retracted cylinder needles) without being knitted by the then co-operating cylinder and rib needles, and a rib stitch cam opposite to the cylinder stitch cam at the knitting station.

11. A circular rib knitting machine according to claim 10, wherein the rib cam system includes a withdrawable transfer cam for advancing rib needles to an appropriate position to facilitate transference of knitted loops from these rib needles to receiving cylinder needles, and a cam for thereupon retracting said rib needles to an inactive position preparatory to the knitting of plain fabric patterned by isolated intarsia designs.

12. A circular rib knitting machine according to claim 10, wherein the rib cam system includes, in advance of the non-knitting station, a cam advancing rib needles seriatim, a latch opener and latch guard engaging with the latches of the needles so advanced, and a cam thereupon retracting the rib needles (With now open latches) to an inactive position.

No references cited.

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