US3488981A - Knitting machines - Google Patents

Description

Jan. 13, 1970 J. J. MILLAR KNITTING MACHINES 6 Sheets-Sheet 1 Filed Feb. 8, 1968 R W WA WM N L 20 E .L 4% WW 2 N Nu ON mm #m mt mm mm On mmmm ATTOR NEYS Jan. 13, 1970 J. J. MILLAR 3,488,981

KNITTING MACHINES Filed Feb. 8, 1968 6 Sheets-Sheet 2 INVENTOR JOHN J. MILLARI ATTORNEYS Jan. 13, 1970 Filed Feb. 8, 1968 J. J. MILLAR KNITTING MACHINES 6 Sheets-Sheet 5 INVENTOR JOHN J. MILLAR ATTORNEYS Jan. 13, 1970 Filed Feb. 8, 1968 J. .1. MILLAR 3,488,981

KNITTING MACHINES 6 Sheets-Sheet 4 ,zos

F i G. 6.

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mvsmon JOHN J. M l LLAR ATTORNEYS Jan. 13, 1970 J. J. MILLAR 3,488,981

KNITTING MACHINES Filed Feb. 8, 1968 6 Sheets-Sheet 5 F I G. 4.

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INVENTOR JOHN J. M I LLAR BY MQVEA/A/X Awe/Mara, Pen/Que 6 4 ATTORNEYS Jan. 13, 1970 J. J. MILLAR 3,488,981

KNITTING MACHINES Filed Feb. 8, 1968 e Sheets-Sheet 6 w R 3 N u N w o w N m h 9 w H Ffm IJUHWUU UUUU'JUUUUUUUUUUU INVENTOR JOHN J. MILLAR ATTORNEYS United States Patent 3,488,981 KNITTING MACHINES John J. Millar, Laconia, N.H., assignor to Scott & Williams, Inc., Laconia, N.H., a corporation of Delaware Continuation-impart of application Ser. No. 680,226, Nov. 2, 1967. This application Feb. 8, 1968, Ser. No. 703,949

Int. Cl. D04b 9/26 U.S. Cl. 66-41 Claims ABSTRACT OF THE DISCLOSURE A knitting machine for the knitting of stockings beginning with the toe and terminating with a turned welt followed by a tab is provided with a heating device which causes fusing of its yarns in the tab to give it high resistance to raveling.

The present application is a continuation-in-part of my copending application, Ser. No. 680,226, filed Nov. 2, 1967, now abandoned.

BACKGROUND OF THE INVENTION The present invention is particularly directed to an improvement in the machine and method for stocking production described in Currier Patent 3,340,706 dated Sept. 12, 1967.

In accordance with this patent stockings are knit having the particular characteristic that toe pockets are produced by twisting fabric to effect closure without recourse to the usual looping procedure. For achievement of this type of toe pocket the stocking is preferably knit beginning at the toe, the knitting then proceeding through the foot, heel and leg portions, followed by the formation of a turned welt. The turned welt comprises a pair of plies with the last knitted having its final course transferred to the needles to close the welt. The operation cannot be terminated by this transfer, but knitting must be continued to form a short tab since otherwise the transferred stitches would immediately open up. In accordance with the patent the tab is provided with run resisting structure and curls in such fashion that there is substantial resistance to raveling. However, handling of the stocking in use may initiate raveling causing disengagement of loops to the extent that the raveling may reach the transfer line with resulting opening of the turned welt.

SUMMARY OF THE INVENTION In accordance with the present invention, the antiraveling characteristics are augmented by using an electrical heater to fuse a number of adjacent courses in the tab during the continued knitting of the terminal tab courses. The yarns used during the knitting of the portion to be fused may be of any thermoplastic yarn having such characteristics that upon the application of the requisite amount of heat the yarns fuse and bond to each other while maintaining the basic structure of the fabric. As a result of the embrittlement of the yarns in this fused zone after the stocking is pressed off, the terminal portion of the tab knitted subsequently to the fused zone may be broken loose and discarded and the fused zone will tend to curl up and be substantially enclosed in the curl of the tab fabric.

The stocking may be knit in the fashion described in said Currier patent up to the formation of the tab. After transfer the knitting proceeds with run-resistant stitches and after a number of courses an electrical heating element is energized and inserted within the needle circle closely adjacent the tab. Just prior to this, by cam selection the needles near the heating element are drawn down and the sinkers withdrawn for clearance purposes. The machine speed is reduced and tension is relieved so that the knitted courses of the fabric extending inwardly from the needle circle assume a wave-like formation of peaks and valleys. The applied heat then causes fusion of the courses adjacent the heating element with greater fusion and deterioration taking place at the peaks to give the effect of a perforated tear line. After sufiicient fusing, the needles are cleared and the fabric pressed off. The last knit course or waste ring outward of the fused zone is then easily removed and discarded and the natural curl causes the remaining tab to curl up so as to be almost unnoticeable.

In order to retain the knitted structure of the fabric in the fused portion remaining on the tab after the waste ring has been separated, it may be desirable to knit alternate courses of different types of yarn of which one course is more readily fusible than the other. This may be accomplished by utilizing one yarn having a lower melting point than the other yarn or it may be accomplished by utilizing one yarn of a lower denier and having the same melting point so that the lower denier yarn will tend to fuse before the higher denier yarn.

The objects of the invention relate to the satisfactory achievement of what has been outlined and various detailed objects will become more apparent from the following description and drawings.

DESCRIPTION OF THE DRAWINGS- FIGURES 1A, 1B and 1C are successive portions, in sequence from top to bottom, of a vertical section taken through the knitting machine provided in accordance with the present invention;

FIGURE 2 is a fragmentary section taken on a plane indicated at 2-2 in FIGURE 1A;

FIGURE 3 is a schematic diagram of the electrical connection leading to the heating element;

FIGURE 4 is a fragmentary plan view illustrating the arrangement of the fabric as formation of the selvedge takes place;

FIGURE 5 is a development of the cams operating on the needles and jacks, showing other associated elements; and

FIGURE 6 is an elevation, partly in section, showing particularly certain pneumatic elements of the machine.

DESCRIPTION OF THE PREFERRED EMBODIMENT Only so much of the knitting machine is shown as is involved in the matters pertinent to the present invention, and references may be made to the foregoing Currier patent for other aspects of the machine and operation. This patent goes into detail concerning the matters of formation of the twisted toe and the other portions of the stocking, including the formation of the turned welt, preceding the tab formation, which is the matter of concern herein. References will be made first to aspects of construction which are essentially illustrated in said Currier patent.

The needle cylinder 2, driven for rotation and reciprocation, is provided with slots slidably mounting the latch needles 4 provided with the usual butts 5, the arrangement of which in the needle circle is as described in the Currier patent. Individually located below the needles in the same slots are the intermediate jacks 6 provided with butts 7, and beneath these are the usual pattern jacks 8 provided with the selectively removable butts 10 and with upper butts 12 and lower butts 14, these jacks being of the tiltable type provided with fulcra at 16 above which they are provided with ends 18 engageable by cams which tilt the lower ends outwardly for selection. These jacks are selected not only for conventional patterning operations but also to provide needle selection for various special operations in make up and the like. The actuating cams for the selected butts 10 will be hereafter mentioned, without detailed discussion, however, of the conventional cam controlling means.

A sinker dial 20 and a sinker ring 22, both mounted to rotate and reciprocate with the needle cylinder, mount the sinkers 24 which are provided with the usual butts 26 acted upon by conventional cams mounted in the sinker cap 28. These sinkers provided with nebs and ledges are operated in the usual fashions at the two feeds.

The latch ring of the machine is indicated at 30, and mounts bracket arrangement which serves for the mounting of various parts as shown in said Currier patent. The latch ring, as usual, is pivotally mounted so that it can be raised, carrying with it the bracket and the parts mounted thereby.

A transfer dial 34 is slotted to mount the transfer elements 40. These elements 40 are formed of two members associated side by side. These elements are provided with butts, those associated with the longer butt needle being high as indicated at 42 while those associated with shorter butt needle are low as indicated at 44. The differentiation of butts is merely to provide for the possibility of proper insertion and removal of operating cams. The dial cap 36 mounts certain cams and also the outer cam ring 38.

Continuing the description of the basically conventional elements of the machine, reference may now be made to FIGURE showing in development various cams and other elements.

The latch ring 30 is provided at the main feed with a throat plate 46 from which yarns are fed from the usual feeding fingers of which only one is indicated at 48 in active position. Conventional yarn changing controls are used as will be readily understood to substitute different weights or types of yarn as desired. At the auxiliary feed a similar throat plate 50 is provided, and here also there are located the substitutable yarn feeding fingers of which only one is indicated at 52. Located at these feed positions are nozzles 54 and 56, to direct blasts of air inwardly against the fabric which is produced, thereby controlling its position and providing desired tension.

Cams and other elements operating on needle butts are generally conventional. A fixed cam 58 is arranged to raise needles to tuck height, and this is followed by radially movable cams 60 and 62, respectively adapted to raise needles to cleared height and to lower them to welt level. A fixed cam 64 raises needles to tuck level. The main feed center cam 66 is flanked by the forward and reverse stitch cams 68 and 70 and their respective landing cams 72 and 74. A cam 76 following stitch cam 68 is arranged to raise needles to tuck level. Another cam above this indicated at 78 may raise needles to a low cleared level and this is followed by a cam 80 which may lower needles to tuck level. Following this is a further cam 82 arranged to raise needles to cleared level. All of these earns 76, 78, 80, and 82 are radially movable.

A pair of separate cams '84 and 86 constitute jointly the stitch cam arrangement at the auxiliary feed. Associated with the cam 86 is the landing cam 88, which is followed by the cam 58 already mentioned.

A radially movable cam 90 is located beyond cam 64 to lower needles. The usual switch cams 92 and 94, both radially movable, are provided. The lowering picker is indicated at 96, while the raising pickers 98 and 100 are indicated in inactive positions. In may be remarked that heel formation in accordance with the present invention is essentially conventional, though the sequence of heel formation is reverse, the lower or forward portion of the heel being first formed followed by the upper or rear portion. As specifically described in said Currier patent, the heel is formed single feed. It will be understood, however, that conventional arrangements for two-feed knitting of the heel may be provided.

The usual cams are provided at 102 and 104 for lowering the intermediate jacks 6 by action on their butts 7.

Conventional cam levers 106 are provided preceding the main feed for the selection of pattern jacks by action on butts 10 thereof. The cam levers 106 rock the lower ends of the pattern jacks inwardly, and those which are so rocked miss the jack raising cam 108 which acts on the butts 14 of those pattern jacks which are not rocked inwardly. In similar fashion pattern selection levers 110 are provided between the main and auxiliary feeds and are associated with a jack raising cam 112. Jack guard cams 114 and 116 are provided as usual. Cams 118 and 120 preceding the respective selecting cam levers 106 and 110 are arranged to engage the upper ends 18 of the pattern jacks to rock their lower ends outwardly for selection.

Referring to FIGURES 1A and 2, the heating assembly comprises the stationary bracket 122 fastened to the latch ring. An H-shaped block 124 carries the remainder of the assembly and is mounted in position by pivot pin 126 held in position by screw 128. By this arrangement the assembly may be adjusted and set to locate the heating element 134. A slot is milled in the latch ring to provide space for the unit. Slide 130 is movable in recessed parallel slots 132 in the block 124. The heating element 134 is formed as a generally U-shaped loop swayed into two larger diameter parallel electrodes 136 that are inserted in brass terminal blocks 138 and clamped by screws 140. Conductor wire terminals 142 are fastened to the terminal block 138 by screws 144. A fibre T-shaped member 145 provides an insulator between the terminal blocks 138 and slide 130. Screws fasten the terminal blocks 138 and slide 130 to the insulator 146 in a fashion to maintain the required insulation of the conductive metal components.

The operative position of the heating element 134, as shown in FIGURE 1A, is adjustable in its position by stop screws 148 bearing against block 124. Set screw 150 holds the stop screw 148 in position.

A conventional Bowden cable 152, having a sheath secured to the stationary bracket 122, is tensioned by the usual connections operated by cams on the main pattern drum to compress the spring 154 to move the slide assembly to operative position. The heating element 134 is moved radially outwardly beyond the needle circle to its inactive position upon movements of the main pattern drum, as will be evident hereafter, by permitting the main cable to slacken so that spring 154 shifts the slide assembly outward.

The electrical connections are illustrated in FIGURE 3. Alternating current line terminals 156 are connectable through a main switch 158 to the primary winding of a transformer 160 which is desirably of a voltage-stabilizing type to provide a regulated output from its secondary to the variable inductor 162 which may be manually to preset to supply a voltage output, the adjustment being conventionalized as a variable tap 166.

The output is delivered through a normally closed switch 168 (connected in the conventional stop motion elements of the machine) and through a second series switch 170 to the step-down transformer 172 which provides the desired output, at low voltage, to the heating element which is conventionalized in FIGURE 3 as a resistor. The switch 172 is closed at the times when energization of the heating element is desired by camming on the main cam drum of the machine.

The heating element 134 is desirably of a temperature resistant material such as a nickel-chromium alloy and may be operated through the adjustment described at any temperature suitable to produce the desired amount of fusing action.

Referring to FIGURES 1A and 4, the sinker cap is slotted at 174 to provide a mounting location for a stationary bracket 176. For sinking withdrawal a sinker cam 178 is attached to a radially movable slide 180 extending through the slot 174 and slide 180 is controlled and set in conventional manner from the main drum camming through the use of a Bowden cable 182 and stop screw 184. The sinker cam 178 is normally out of operation and is brought into operation to withdraw the sinkers just before the heating element 134 is brought into operation.

Referring to FIGURE 5 which shows the cam ring layout, at the same time as the sinker cam 178 is actuated and prior to the introduction of the heating element 134 the needles in the area of the heater element 134 are lowered by cam 62 to welt height, and remain at this level until they are elevated by cams 64 and 70.

As is shown in FIGURE 4, after the sinkers and needles have been withdrawn, the heating element 134 is shifted into the active position inward of the needle circle. At the same time, the tension on the knitted stocking is relieved so that the material naturally tends to wrinkle and pucker to form peaks and valleys in the tab fabric 186 as indicated by the shading in FIGURE 4. It will be understood that at this point transfer has already taken place and that portion of the tab fabric 186 has already been knit after transfer. The transfer courses are shown at 188, while 190 indicates the inside face of the inturned welt fabric as it is gathered toward the upper edge and inwardly into the fabric receiving tube, the fabric being further indicated at 192.

The fabric tensioning system is in part shown in FIG- URES 1A and 1B and 1C, Tubular member 200 replaces the funnel-shaped member 220 of saidCurrier patent. Elongated ports 202 are provided opposite the suction source opening 204 in the cylinder raising tube 205. A clamp ring 206 services to maintain supportand concentricity of the fabric tube 207, as well as providing a closed end for chamber 208. Tubular member 200 is fastened to the clamp ring 206 by screws 210. Tubes 200, ring 206, and fabric tube 207 are driven by, and rotate with, the needle cylinder.

A ring 212, fastened to the cylinder raising tube 205 by screws 214, serves as a closed end for chamber 216. Though suction may be applied at required times from ports 206 through chamber 216 to chamber 208, a stationary flanged bushing 218 is supported by ring 212 and serves as a bearing corresponding to 230 of the Currier patent. Fitting 218 and tube 220 correspond to the members 228 and 226, respectively, shown and described in the Currier patent.

Referring next to FIGURE 6 which is a diagrammatic illustration of the pneumatic tensioning system, the suction source is represented by a motor-driven centrifugal blower shown at 230. The conventional portion of the system comprises suction tube 232, chamber 234 and fabric-receiving tube 220. After press-off the stocking is delivered to chamber 234. By operation from a main cam drum move, valve 236 is closed and door 237 is opened to drop the stocking into a collecting receptacle.

To provide suction to the welt chamber 208, a branch tube 238 and valve 240 are provided. During the initial part of welt knitting, a main cam drum move effects opening of valve 240 to divide the suction to both the fabricreceiving tube 220 and chamber 208. The setting of valve 240 is adjustable to secure a satisfactory tension on the welt, the adjustment depending upon the weight of the fabric.

Just prior to transfer, and to avoid hanging up of the fabric on the dial bits, valves 240 and 236 are closed, resulting in no tension being applied to the fabric. The tension is also eliminated by closure of these valves during the knitting of the tab. Immediately after press-off, valve 236 is opened to suck the completed stocking into chamber 234.

In addition to the tensioning on the welt by the suction, air under pressure flows through the nozzles 54 and 56 (FIGURE 5) to aid in positioning the initial courses of the welt fabric into chamber 208.

In the production of a typical stocking, the operation from make up to the beginning of the welt is as described in said Currier patent and need not be repeated. During this knitting tension is maintained on the fabric by suction through the tube 220, the valve 236 being open, while the valve 240 is closed.

The welt is begun in the fashion described in said Currier patent, and knitting thereof proceeds as therein described. However, using what has been disclosed, following the initiation of welt knitting both valves 236 and 240 are open and air jets are produced through the nozzles 54 and 56 shown in FIGURE 5. The result is that the loop of fabric constituting the turned welt is introduced into, then maintained in proper condition in the region 208. In particular, proper tension is applied to the fabric as it is produced on the needles.

Just before the transfer of loops from the dial elements to the needl;s is to occur, both valves 236 and 240 are closed by a move of the main cam drum of the machine to interrupt the suction action. The purpose of removing tension just before transfer is to avoid possible hanging up of any portions of the fabric on the transfer elements. The suction now remains off during the formation of the tab. In the preferred operation the tab is knit two feed either with or without run resist structure of the type shown and described in said Currier patent. Of course, more or less feeds may be used depending upon the machine. While a run resist structure may be preferable for its added effect, the principal provision for raveling resistance is provided by the fusing action and the run resist structure is therefore of lesser importance. Generally, for both purposes of continuity and to provide a proper fused structure, it is desirable to continu the knitting with the heavier yarn of the type used for the knitting of the welt. The use of a heavier yarn at this point results in a better fused structure as well as greater strength. The yarn used may be of any fusible thermoplastic type, including any of the nylons normally used for the knitting of stockings. Alternatively, other thermoplastic yarns may be used and in different combinations as will be described in greater detail hereinafter.

After transfer has been completed and the knitting of the tab begins, a number of courses are knit before the heating element is brought into active operation in order to allow the transfer courses to move farther inward from the needle circle. After a number of courses have been knit, the cam 178 is brought into operation to effect the special sinker withdraw-a1 and the needles are brought down to the welt position in the region where they pass the heater 134 as previously described. Whil the heater is in position, knitting is continued so that newly formed courses move progressively beneath the heater to generally extend the width of the fused zone. Only after the heater is withdrawn is the knitting terminated and the stocking pressed off.

Where the heating element 134 is moved into the active position, it is so located with respect to the fabric as to engage the high portions of the tab fabric. As has been previously mentioned, and as shown in FIGURE 4, because of the absence of tensioning, the fabric will tend to pucker to have .a wavy configuration which is particularly advantageous in the operation involved. As the tab nears completion, switch is closed to provide the heavy current through the heating element 134 to bring it to the desired temperature suitable for the particular yarns which are involved in the tab. Desirably, the knitting machine is also now slowed down to permit the heating to be more effective. Generally, it has been found necessary to retain the heating element 134 at the particular fusing temperature set by the setting of the variant inductor 162 only for a relatively short period of time, and usually, the minimum time is determined by one chain link or typically four revolutions of the cylinder on a typical machine.

During the fusing operation, the heater is positioned so as generally to contact only the peaks of the tab fabric, although actual contact is not necessary and if lower fusing temperatures are desired, the heater may also be positioned to contact all portions of the fabric. Under the condition where the heater contacts only the peak portions, greaterfusing will take place at these points and preferably may result in a greater degree of melting so that because of the natural tendencies of the fiber, small openings may be melted into the fabric resulting in an effect somewhat similar to perforations. However, it is important that fusing be suificient as to cause an actual adhesion if not complete melting in a continuous zone in the tab so as to positively prevent any raveling from beginning at this point. It will be understood that the fusing effects result in an embrittlement .of the yarn which aids in removal of the waste ring as described hereinafter.

Following completion of the tab forming operation, press off is effected by withdrawal of the yarns and clearing of all of the needles. The valve 236 is then opened (valve 240 remaining closed) with the result that the pressed off stocking is drawn through the tube 220 into the chamber 234. The knitting may then be immediately resumed by makeup for the next stocking.

From the finished stocking there may be manually torn off the terminal portion of the tab to remove bulk. This may be accomplished, though not necessarily at a definite course, by reasoning of the weakening of the structure beyond the portion which serves as a selvedge, since the tab, as it comes off the machine, may be generally perforated as described hereinbefore at various points and quite weak at the remainder so that this removal is simple. After the removal of this remaining portion or waste ring of the tab, various yarn ends may be broken where the loops have been severed. However, the presence of these ends will not cause any tendency to run even though the yarns at thls point may not be completely fused because the fusing takes place over a sufficient number of courses that there will be sufficient fusion or adhesion between contacting yarns to positively prevent any raveling. Although this fused portion may therefore appear somewhat rougher and less flexible, due to the natural tendency of the tab fabric to curl, the residual portion becomes rolled into a circumferential roll or curl so that the rough selvedge edge is well hidden and effectively protected against abrasion or other action which might tend to destroy the selvedge and thus permit raveling.

Although as heretofore described, it is not necessary to provide any special yarn in the portion of the tab to be fused, it may be desirable to provide more selective meltlng or fusing of the tab yarns. This can be accomplished by either simultaneously or alternate feeding of yarns having different melting characteristics. For example, assuming that the stocking is primarily knit of nylon, in the tab the nylon may be knit alternately with polypropylene yarn in two feed fashion, the polypropylene having a lower melting point than the nylon. Alternatively, alternate courses may be knit of two types of nylon, for example, Type 6 and Type 66. In this particular Instance, the Type 6 nylon melts at about 420 F. and Type 66 nylon melts between 445 F. and 480 F. Polypropylene typically melts in the range of 325 F. to 350 F., substantially lower than themelting point of the various nylons. With the foregoing construction, the lower melting point nylon may have either a higher or lower denier and since the structure may be supported, where the lower melting point yarn is knit together with a similar yarn of higher melting point, the knit structure is maintained even if the lower melting point yarn is completely melted and fused to the higher melting point yarn.

Another arrangement may be merely to mix yarns of the same material having the same melting point but with one of the yarns having a lower denier. In this case, in view of the lower cross-sectional area and the constant rate of heat input, the lower denier yarn will fuse or soften and reach a tacky state prior to the higher denier yarn which will therefore retain substantially the full structure of the fabric.

The suctioning type tensioning means above described 8 is the subject matter claimed in the application of John A. Currier, Ser No. 680,224, filed Nov. 2, 1967. The matter of formation of a tab selvedge described herein may be used without the special tensioning means, i.e. in conjunction with such aspects of tensioning as are involved in said Currier patent.

What is claimed is:

1. A circular knitting machine comprising a pair of circular substantially coaxial beds, elements, including needles, mounted throughout the circumference of, and for movements in, said beds, devices cooperating with said elements for their operation and the formation of stitches, elements, mounted in a first one of said beds being arranged to hold a tubular knitted portion of fabric during further rotary knitting of tubular fabric by elements mounted in the other of said beds, means for effecting transfer of loops from the elements of the first bed to the elements of the other bed to form a closed loop of fabric, means for thereafter effecting further knitting of terminal courses of a knitted product by elements in said other bed, the last mentioned means comprising means for feeding to the last mentioned elements at least two yarns, one of which has a lower melting point than the other, and means for applying heat to the fabric being produced during the knitting of said terminal courses to effect at least softening of the yarn of lower melting point to provide a structure substantially resistent to raveling.

2. A knitting machine according to claim 1 in which said heat applying means comprises an electrically heated member positioned for engagement with the terminal courses.

3. A knitting machine according to claim 2 in which said heated member is movable to and from its active heating position.

4. A circular knitting machine comprising a needle cylinder, needles mounted in said cylinder for movements.

therein, devices cooperating with the needles for their operation and the formation of stitches, said devices including means for knitting terminal courses of a knitted; product, the last mentioned means comprising means for feeding to the needles at least two yarns, one of which has a lower melting point than the other, and means for applying heat to the fabric being produced during the knit ting of said terminal courses to effect at least softening of the yarn of lower melting point to provide a structure substantially resistant to raveling.

5. A knitting machine according to claim 4 in which said heat applying means comprises an electrically heated member positioned for engagement with the terminal courses.

6. A knitting machine according to claim 5 in which said heated member is movable to and from its active heating position.

7. The method of forming terminal courses of a circular knit product comprising providing to needles for the formation of said courses at least two yarns, one of which has a lower melting point than the other, and during the knitting of the terminal courses applying heat thereto to effect at least softening of the yarn of l wer melting point to provide a structure substantially resistant to raveling.

8. A circular knitting machine comprising a pair of circular substantially coaxial beds, elements, including needles, mounted throughout the circumference of, and for movements in, said beds, devices cooperating with said elements, for their operation and the formation of stitches, elements mounted in a first one of said beds being arranged to hold a tubular knitted portion of fabric during rotary knitting of tubular fabric by elements mounted in the other of said beds, means for effecting transfer of loops from the elements of the first bed to the elements of the other bed to form a closed loop of fabric, means for thereafter effecting further knitting of terminal courses of a knitted product by elements in said other bed, and means for applying heat to the fabric being produced during the knitting of said terminal courses to effect at least softening of the yarn of at least one course to provide a structure substantially resistant to raveling.

9. A knitting machine according to claim 8 in which said heat applying means comprises an electrically heated member movable to and from its active heating position adjacent said terminal course.

10. A circular knitting machine comprising a needle cylinder, needles mounted in said cylinder for movement therein, devices cooperating with the needles for their operation and the formation of stitches, said devices including means for knitting terminal courses of a knitted product, and means for applying heat to the fabric being produced during the knitting of said terminal courses to effect at least softening of the yarn of at least one course to provide a structure substantially resistant to raveling.

11. A method of forming a non-raveling selvedge of a circular knit product comprising knitting a first group of courses while applying tension to the fabric during knitting, and knitting a second group of courses after said first courses have moved a given distance inward from the needles, and during the knitting of said second group of courses applying sufficient heat to said first courses to effect at least softening and fusion of at least some of the yarns in a zone of said first courses, and after said fusion is completed, terminating the knitting.

12. A method of forming a non-raveling selvedge on a circular knit product as set forth in claim 11, including the additional step of removing said second group of courses by breaking the yarns in said first group of courses in said fused zone.

13. A method of forming a selvedge on a circular knit product as set forth in claim 11 wherein said first group of courses is knit from at least two yarns, one of said yarns being more readily fusible under the applied heat than the other of said yarns.

14. A method of forming a selvedge on a circular knit product as set forth in claim 13 wherein said more readily fusible yarn has a lower melting point than the other of said yarns.

15. A method of forming a selvedge on a circular knit product as set forth in claim 13 wherein said more readily fusible yarn is of the same material as the other of said yarns but has a lower denier to provide a decreased crosssectional area.

References Cited UNITED STATES PATENTS 2,388,144 10/1945 Headon 66-169 XR 2,437,735 3/1948 Getaz 66-147 2,460,674 2/ 1949 Bihaly.

2,485,230 10/ 1949 Alexander et al. 66--202 XR 2,594,821 4/1952 Tingley.

2,608,078 8/1952 Anderson 66-176 2,811,029 10/1957 Conner 66-202 XR 3,015,223 1/1962 Moore 66147 3,125,052 3/1964 Spivey 66145 XR 3,286,490 11/1966 Martin 28-73 XR 3 3,340,706 9/1967 Currier 6626 FOREIGN PATENTS 278,243 11/ 1964 Netherlands.

RONALD FELDBAUM, Primary Examiner US. Cl. X.R.

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