US2975622A - Circular knitting machines - Google Patents

Description

March 21, 1961 H. BOOTON ETAL CIRCULAR KNITTING MACHINES 3 Sheets-Sheet 1 Filed Nov. 30, 1956 Inventors HERMAN BOOTON HERBERT NEAL y HIIIIIIIIIIIIIIIIIII MGM Attorneys 3 Sheets-Sheet z mentor HERMAN BOOTON HERBERT NEAL d r B) jm F Attorneys March 21, 1961 H. BOOTON ETA].

CIRCULAR KNITTING MACHINES Filed Nov. '30, 1956 H. BOOTON ETAL CIRCULAR KNITTING MACHINES 3 Sheets-Sheet 3 Inventors HERMAN BOOT 0N HERBERT NEAL Attorneys a p 2,975,622 CIRCULAR KNITTING MACHINES Herman Booton and Herbert Neal, Leicester, England,

. assignors to W. E. Booton Limited Filed Nov. 30, 19 56, Ser. No. 625,454 Claims priority, application Great Britain Dec. 2, 19 55 8 Claims.- cr ss-149 This invention isfor improvements in or relating to circular knitting machines, and has particular reference tothat type of knitting machine which is known as a seamless hose machine and is employed for the manufacture of womens seamless stockings. More especially the invention concerns machines equipped with inturned welt mechanism, and machines employed'for making stockings in an all-over tuck stitch fabric (such stock ings being commonlyknown as micro-mesh'stockings) knitted of nylon or .like fine filaments. e t Inseamless hose machines in which the stockings are knitted as a.continuous chain, it is customary to provide take-downmechanismwhich draws the being-formed tube offabricaway from the needles; However, in'the case of machines which, like the Scott and Williams Model K machine, are equipped with inturned welt mechanism. each stocking on completion is pressed oif theneedles and for this reason'it is difficult to provide any satisfactory formlof take-down mechanism. While the inturned welt is being knitted an initial course of the welt fabric is. held by welting instruments mounted in a dial and the. cylinder needles continue to knit-welt fabric so that a loop of fabric isformed below the dial and within the compass of the needle circle, Since it is not possible to grasp this fabric by any form of takedown mechanism there a danger, especially when nylon yarn is being used, that the fabric will bunch" and in consequence when long loops are being knitted (as is necessary :for maximum width) the fabric made inthis way is ,of a poor andundesirable appearance. In the case of micro-mesh stockingsknitted of "nylon, the quality of the fabric produced is (owing to the absence of take-down mechanism) liable to be inferior to that.

whichis desirable and in particular the leg fabric suffers froman undesirable accumulation of double tucking, and dropstitches. r I

The present invention provides in the production of sucked into a receiver and is then blown out of the latter.

This invention also includes a circular knitting machine, and particularly a seamless hose machine having inturned welt mechanism, having suction means fordrawf' ing off the fabric as production continues.

Each machine according to this invention may be'provided with its own individual suction-creating device, Alternatively there may be a suction-creating device common to a plurality of machines. a

In order that the invention may be'better understood reference will now be made to the accompanying draw ings in which: i 1

' Figure l is a perspective view of therelevant parts of a seamless hose machine having inturned welt mechanism (and if desired mechanism for producing all-over tuckstitch fabric) and incorporating the present invention;

Figure 2 is a sectional view of the upper end of the needle cylinder, the inturned welt mechanism and the conduitaforesaid; I

Figure 3 is a plan 'view of a partof the mechanism shown in Figure 2; l Figure 4 is a view, partly in side elevation and partly in section, showing. the lower end of the suctiontubeythe suction means or fan, and the electric motor driving it;

Figure 5 is a view partly 55;'in Figure'4; I

Figure 6 is a sectional view of the valve, hereinafter described, in the suction attitude; Figure 7 is a part sectional view looking in the direc 1 tion of the arrows 7-7 in Figure 6;

Figure 8 is a sectional view showing the valve inth e blowout or discharge attitude, and I Figure 9 is a part-section view lookinginthe direction of the arrows 9'9 in Figure 8. Figures 1, 2 and 3 illustrate a seamlesshosemachine ofthe type having inturned welt mechanism (and if desired mechanismof a conventional character for producing all-over tuck-stitch ormicro-mesh fabric). Such inturned welt mechanism and micro-mesh mechanism is well known and needs no description or'illustration heree The machine is indicated generally at 10 in Figured. It has a rotating needle cylinder 11 equipped with individual latch needles 12, and in Figure 2 there is illustrated the relevant portions of the inturned welt mechanism 15 1 comprising the dial 13 and. the weltinstruments or welt tubular fabric ona circular knitting machine, a method disposed within .and having an entry of smaller size than the needle circle. Best results are obtained if the radial distance between the end of thehconduit andthe needle circle varies round the. needlecircleJ Preferably the entry end is disposed eccentrically (e.g. A") within the needle+circ1e.- iIt has been found that this'clispo sition facilitates theflentryiof the weltv fabric into it. Alternatively, the entry end of the tube may be oval.

. According to a subsidiary feature of the. invention, alength of a fabric tube .(eg. a complete. stocking) is hooks 14. t

In Figure 3 one 56 and the splicing feeder at 5 7." -1 l l The machine is. equipped with a .suction device :16 comprising a multi-stage rotary fan, blower-or the like 17, driven from a suitable-source of power suchfor example as an electric motor-18,"a belt drive 19 being illustrated. .The suction device 16 hasits inlet 20, Fig. 6 connected to a receiving tube or chamber 21" which at an intermediate position in its height is connected by a suction pipe 22 to the lower end of the suction tube 2,3 comprised in the suction. conduit aforesaid. -This suction conduit extends up withinthe-needlecylinder-11 and has its upper end locatedjust below the dial '13. Specifically the upper end of the tube 23 engageswith a hollowboss 24, ona partition 25 which is disposed with in a stationary tube 26 andhas a funnel-shaped'upper end27. The interior ofthe boss .24 providestheentry end 280i the suction conduit.

Thus the. suction means 16 sucks air through the tube downwards. The diameter of the entry end 283 is: less Patented Mar. 21, 1961 insection taken on the'line of the main yarn feeders is shown at than that of the needle circle and is less than the internal diameter of the needle cylinder 11. It may be mentioned by way of example that in the case of a 3% or 3 /2" needle cylinder the entry end may be 1 /2 diameter.

It is important that the radial distance between entry end 28 of the suction conduit and the needle circle shall vary around the needle circle. This effect is best achieved by disposing the entry end 28 eccentrically to the needle circle as illustrated in Figure 3 which also shows an advantageous disposition of the entry end in relation to the feeders 56, 57. It has been found that this greatly facilitates the entry of the double thickness of welt fabric into the suction conduit. It has been found that if the conduit is disposed centrally there may be a tendency for the double thickness of welt fabric to get trapped against the upper end of the conduit or against any such parts as the closure plate shown at 25, before this fabric can enter the conduit. On the other hand. with the arrangement illustrated, during the initial stages of the production of the welt fabric and as the lower end of the double thickness of welt fabric gradually approaches the entry end 28, a phase will be reached at which owing to the eccentricity an are or area of the welt fabric enters the entry end 28 and is subjected to the full effect of the downward draught of air. Moreover the are or area of welt fabric which thus enters shifts progressively around the tube of welt fabric so that the draw-off effect progresses likewise and all circumferential parts of the welt fabric are subjected in turn to the suction draw-off. It will be appreciated that in relation to the needle cylinder, the entry end 28 progresses in an orbit around the axis of the needle cylinder. Were the needle cylinder to be stationary the same effect could be achieved by rotating the parts 24, 25 with the knitting cams or other needle-operating means.

The suction device 16 is connected to the suction tube 23 in the following manner. At the inlet 20 of the suction device there is a valve box 29 containing a semirotary valve member 30 of cylindrical form. This valve is movable (e.g. through about 90) between the suction attitude shown in Figs. 6 and 7 and the blow-out or discharge attitude shown in Figs. 8 and 9. In the suction attitude the valve member 3% establishes communication, by means of a port 31, between the bottom of the receiving tube 21 and the entry 29 to 'the suction device 16. Thus suction is applied to the receiving tube 21 and to the take-down tube 23. The air thus sucked into the suction device 16 is exhausted therefrom through a transfer pipe 32 which also leads to the valve box 29, and in the suction attitude of the valve member 30 a port 33 in the latter connects pipe 32 to atmosphere by way of a delivery aperture 34 in the valve box.

Thus there is a tendency for the stocking or fabric knitted on the needles 12 to be sucked down the tube 23 and this suction is the sole means by which the fabric is drawn off the needles. It will be noted that were the fabric pressed off the needles, as at the completion of a stocking, the completed stocking would pass into the receiver 21, its further travel being prevented by a perforated partition or grill 35 at the bottom of receiver 21.

While it is Within the scope of this invention, that a stocking or the like thus sucked into a receiving chamber may be subsequently removed therefrom by hand, yet according to an important subsidiary feature of this invention means are provided for blowing the stocking out of the receiving chamber.

For this purpose the valve member 36 is movable from the attitude shown in Figs. 6 and 7 to the attitude shown in Figs. 8 and 9. in this attitude the port 31 connects the fan entry 20 to atmosphere by way of the passage 34, while the port 33 connects the fan delivery pipe 32 to the bottom of the receiving tube 21. Thus a stocking which has been sucked into the receiving tube is blown V out of it.

The receiving tube 21 is provided at its upper end with a hinged lid 36 which is spring pressed towards the closed position. This lid seals off the upper end of tube 21 while the latter is subjected to suction but when air pressure is applied to the tube 21 the lid opens to permit the stocking to be blown out. If desired the stocking may be blown into a collector and in the illustrated example the top end of the receiving tube 21 leads into a collecting chamber 37 Fig. I mounted on the frame of the machine 10. This collecting chamber 37 has an aperture 38 through which the machine attendant may insert a hand to extract the collected stockings. Desirably the collector 37 is made wholly or in part of a transparent material such as a transparent synthetic resin.

The semi-rotary valve member 30 is biased by a spring 39 towards one of its attitudes and is movable to the other attitude by pin 40 and lever 41 Fig. 5, connected by a connection 42 of the flexible, sheathed, cable type to a lever 43 operated at the appropriate time by a patterning device shown as one of the cam drums 44 of the machine. It has been found advantageous to interrupt momentarily the suction. exerted on the stocking immediately before the latter is pressed off (cast off) the needles. Otherwise when the sticking is pressed off and sucked down the tube 23 it will draw a long length of yarn from the feeder. To avoid this, suction is suspended until such time as the yarn extending from the last knitted loop to the feeder has been cut and trapped by conventional cutting and trapping mechanism. This interruption in the suction is achieved by a semi-rotary valve tube 45 located inside the receiving tube 21 and having a port 46 movable into and out of register with the end of pipe 22. The valve tube 45 is spring biased to one of its two attitudes, for example by means of a spring 47 connected to a pin 48 extending from the tube 45 through a slot 49 in tube 21. The valve tube 45 is moved to its other attitude against the action of spring 47 by means of a lever 50 acted on by a connection 51 of the flexible, sheathed, cable type operated by a lever 52 from a patterning device shown as one of the cam drums 53 of the machine.

Thus before the start or after the set up or the start of a stocking (or at any other desirable phase) the semirotary valve member 30 is moved by cam drum 44 to the suction position. Immediately before the finished stocking is pressed off the needles the valve tube 45 is momentarily moved by the cam drum 53 to the suction cut-off position. The stocking is pressed off and the yarn cut and trapped. The valve tube 45 then returns to the suction position and the completed stocking is sucked to the bottom of the receiving tube 21. Valve member 30 is thereupon moved by the cam drum 44 to the discharge or blow-out attitude and the completed stocking is blown up through the tube 21 into the collector 37.

It is within the scope of this invention to provide a single suction fan and receiving chamber or collector for a plurality of machines. In such an arrangement, since all the machines deliver to a common collector it is not practicable to blow each stocking out of the latter immediately upon arrival. Instead the collector may be blown out or emptied periodically and in order to avoid interruptions in the production sequence while this is taking place there may be two alternative collectors, matters being so arranged that when it is desired to empty one the. suction connections are changed over to the other one by suitable valve mechanism so that the two 001- lectors are used alternately.

It will, of course, be understood, by those versed in the art to which this invention relates, that all surfaces over which the stockings travel must be sufficiently smooth to avoid snagging the stockings. For example the entry end of the vertical tube must be adequately rounded and smooth.

The invention is applicable to single feeder machines, two feeder machines, and to multi-feeder machines (such for example, as are employed for knitting body fabric).

What we claim is:

1. In the production of tubular fabric on a circular knitting machine having a circle of needles, a method of drawing off the fabric tube from the needles as production continues, which comprises the steps of sucking the fabric tube along a conduit disposed within the needle circle and having an entry of smaller size than the needle circle with the radial distance between said entry end and the needle circle varying around the circle, and effecting relative rotation between said entry end of the conduit and the circle of needles.

2. A method according to claim 1, including the steps of sucking a length of the fabric tube into a container and then blowing it out of the latter.

3. A method according to claim 1, including the steps of pressing off a length of fabric from the needles, and momentarily interrupting the suction during the press-01f.

4. A circular knitting machine for knitting tubular fabric, having a circle of needles, a suction conduit for sucking the fabric away from the needles, which conduit has an entry end of smaller cross-section than the needle circle disposed within said circle with the radial distance between said end and circle varying around the circle, means for sucking the fabric tube into said entry end and along the conduit as knitting proceeds, and means for effecting relative rotation between the entry end and circle of needles as knitting proceeds.

5. A circular knitting machine for knitting tubular fabric, having a circle of needles, a suction conduit with an entry end of smaller cross-section than the circle of needles disposed eccentrically within said circle, means for effecting relative rotation between the circle of needles and the eccentric entry end as knitting proceeds, and suction means for sucking the being-knitted fabric tube away from the needles into said entry end and along the conduit.

6. In a circular knitting machine for knitting lengths of tubular fabric and pressing off each length when completed, and having a needle cylinder, and needles movable therein to produce the tubular knitted fabric adjacent one end of the cylinder, the combination of a suction tube disposed within the cylinder with an entry end adjacent said end of the cylinder, which entry end is of smaller cross-section than the cylinder and is eccentrically disposed within the latter, means for effecting relative rotation between said entry end and cylinder as knitting proceeds, suction means for sucking successive lengths of the fabric into the entry end and along the tube away from the said cylinder end, and means for momentarily interrupting the suction as each length is pressed'oif.

7. In a circular knitting machine for knitting lengths of tubular fabric and pressing ofi each length when completed, and having a needle cylinder, and needles movable therein to produce the tubular knitted fabric adjacent one end of the-cylinder, the combination of a suction tube disposed within the cylinder with an entry end adjacent said end of the cylinder, which entry end is of smaller cross-section than the cylinder and is eccentrically disposed within the latter, means for effecting relative rotation between said entry end and cylinder as knitting proceeds, a receiver, in communication with the suction tube, for receiving the fabric lengths therefrom, and means for applying suction to the receiver to suck each length into it and for blowing each received length out of it.

8. A machine according to claim 7 wherein the receiver has a discharge outlet, which machine further comprises a suction-creating device with an air inlet and an air outlet, valve means for connecting the air inlet and air outlet alternately to the receiver and for thereby subjecting the interior of the receiver to suction or pressure, valve-operating means for operating the valve means to subject the interior of the receiver to suction while a length of fabric is being knitted and to air pressure upon arrival of a length of fabric in the receiver, and a closure to the receiver for sealing the latter while subjected to suction and for permitting a length of fabric to be blown out of the receiver when the latter is subjected to air pressure.

References Cited in the file of this patent UNITED STATES PATENTS 2,729,082 Tew Jan. 3, 1956

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