US2902845A - Circular hosiery knitting machines - Google Patents

Description

Sept. 8, 1959 J. J. MODONOUGH 2,902,845

CiRCULAR HOSIERY KNITTING MACHINES Filed Oct. 1, 1957 2 Sheets-Sheet l John J Mcflonoug/r By his affomeys Sept. 8, 1959 J. J. M DON OUGH CIRCULAR HOSIERY KNITTING MACHINES Filed Oct. 1, 1957 2 Sheets-Sheet 2 mQ Q N wik //7 van far Ja/m J Mcflonaug/z By Ms affomeys United States Patent Ofifice 2,992,845 Patented Sept. 8, 1959 CIRCULAR HOSIERY KNITTING MACHINES John J. McDonough, Laconia, N.H., assignor to Scott & Williams, Incorporated Application October 1, 1957, Serial No. 687,457

4 Claims. (Cl. 66-48) This invention relates to circular hosiery knitting machines and more particularly circular multifeed hosiery machines adapted to knit multi-feed during the reciprocatory knitting of heels and toes. In knitting seamless heels and toes by reciprocatory knitting, it is customary to raise one or more needles out of action during narrowing and during widening. During widening it is common, in single feed hosiery machines, to raise one needle out of action and to put two needles down into action on each oscillation. In the patent to Robert H. Lawson, No. 2,440,280 dated April 27, 1948, a machine and method are described in which three needles are lowered into action and one needle raised out of action at each feed in a multi-feed hosiery machine on each oscillation during widening in the heel or toe. The present invention will be described in a machine which raises one needle and lowers three needles on each oscillation during widening.

'In circular knitting machines the yarn coming from the yarn finger to the needles approaches the needle circle in a tangential manner at the same time as it descends from the throat plate to the ledges of the sinkers. This descending length of yarn is known as the yarn lead. It is set by many factors which are not easily susceptible of change. Suffice it here to say that the present invention cures the difficulty about to be described without changing the yarn lead. .During the reciprocatory knitting in the making of seamless heels and toes, the yarn lead has to be reestablished at each feed on each oscillation. Before an oscillation begins the yarn lies between the throat plate and the last needle to knit on the previous oscillation inclined in the opposite direction to the yarn lead next tobe used. It is attached to the knitted fabric at the ledge of the sinker adjacent that last needle. At the throat plate the yarn normally comes over the corner of the plate. However, when an oscillation is just beginning there is a moment while the yarn is being pulled over to the new corner when the yarn comes over the edge of the plate intermediate the two corners. Thus the angle of the yarn lead at that moment is a little flatter than usual. It is at this moment that the trouble occurs which this invention cures.

. It will be recognized that the latches of the needles coming up to the tangent point of the yarn are open, i.e., with their free ends or tips down. It has been found that if the angle of the yarn lead is a little low, the kitchen the first one or two needles following the needle where the yarn is attached to the fabric may pass above the yarn lead before the needles start to descend under the influence of the stitch cam. When this happens, drop stitches will be formed on those needles when they are drawn down to knit, as their latches will have been closed preventing their hooks from seizing the yarn. These drop stitches will occur in the suture of the heel or toe pocket and at times in a following stitch as well. The present invention avoids this difificulty by bringing the active needles to a slightly lower position before they reach the regular "knitting cams. The manner in which this is accomplished in an all multi-feed hosiery machine adapted also to make reinforced and fancy fabric will be hereinafter set forth.

In the drawings Figure 1 is a developed view of the throat plates, yarn leads, needles and knitting cams of a multi-feed hosiery machine viewed from within showing the positions of the parts just at the beginning of a reverse movement of the needle cylinder. The little arrow shows the direction of movement of the needles.

Figure 2 is a view similar to Figure 1 showing the knitting when the leading active needle on the same reverse oscillation is about to contact the regular stitch cam at the right hand feed. This is the second feed to knit on a reverse oscillation.

Figure 3 is a view in elevation of a typical needle such as used in Figures 1 and 2, showing the latch open.

Figure 4 is a perspective view of the mechanism which operates the auxiliary needle cams on the machine of Figures 1 and 2 to lower the needles a little before they reach the regular knitting cams, part of the thrust rod being broken away.

The invention will be shown and described embodied in a two-feed hosiery machine of the general type shown in the US. patent to John J. McDonough, No. 2,756,962 dated December 4, 1951, but some aspects of the invention are not limited to multi-feed machines. The Scott & Williams multi-feed ladies hosiery machine of Mc- Donough and the present application contain the usual revolving needle cylinder 260, independent needles N therein with pivoted latches 10, regular stitch cams 360 and 361 and a double stitch cam 50. There also are the usual lifter picks 650 and 651 to raise needles out of action at the heel and toe and a lowering pick 680 to pick the needles back into action. There are the usual throat plates 560, 561 and pivoted yarn fingers F cooperating therewith. In the present application the horizontal line in Figures 1 and 2 a little distance below the two throat plates and marked sinker ledge is the level at which the stitch measuring ledges of the sinkers (shown in McDonough, No. 2,576,962) are located. It is at this level that the yarns coming from the throat plates and yarn fingers become attached to the fabric.

In multi-feed hosiery machines of the type disclosed above, there is one less throat plate than there are stitch drawing cams, but there are twice as many stitch drawing surfaces as there are throat plates. The so-called right hand stitch cam 361 can act as a clearing cam, if desired, when the knitting is proceeding in a rotary or run down direction, and it is so used during reciprocatory knitting movements in that direction. It also provides a stitch drawing surface for what is the second feed when the needle cylinder is turning in the reverse direction. When the cylinder is turning in the reverse direction the needles are moving from left to right as they appear in Figures 1 and 2. The companion or left-hand stitch cam 360 provides a stitch-drawing surface for the second feed when the cylinder is turning in the rotary direction. It also serves to clear the needles before what becomes the first feed when the cylinder is turning in the reverse direction.

There is a double center stitch cam 50 which has a stitch drawing surface for each direction of knitting. These two surfaces are numbered 51 and 52 in the drawings and each serves as a stitch drawing surface for the first feed in its direction of knitting. When the cylinder is turning in the rotary direction of knitting, the stitchdrawing surface for the first feed is the surface 51. The yarns at this point are supplied from the right hand throat plate 561. a

I will now describe the shape of the double center cam 50 in a little more detail. At each end of the double stitch cam is notch 57 or 57 These are at the upper ends of its stitch drawing surfaces 52, 51. Each end or wing of the cam forms the outside of a notch and is sloped so as to cause any needle guided up into the notch for any purpose to be lowered and lead out again as the needle moves toward the end of the cam. However, the present invention makes use of the notches for an entirely different purpose as hereinafter explained.

The present invention is concerned with ensuring that drop stitches are not formed in and adjacent to the sutures of narrowed and widened heel and toe pockets made by reciprocatory knitting. While these drop stitches can occur on narrowing, particularly if narrowing on two needles at a time, I will describe the prevention of drop stitches during widening where they are more apt to occur. I refer first to Figure l of the drawings which show the situation at the left hand feed just before the needles N start down the stitch drawing surface 52 and the yarn Y leading from the left hand throat plate 560. They are about to become involved in knitting as the reverse stroke begins. As mentioned above, the view is taken from the center of the cylinder looking outward so the needles N are nearer the observer than the length of yarn 12 lying between the finger F and the point at which it is attached to the fabric at the sinker ledge. At the level of this ledge the yarn is attached to the last needle to knit on the preceding forward oscillation. As previously mentioned, this length 12 of yarn lying between the yarn finger and the throat plate on the one hand and the last active needle at the sinker ledge on the previous stroke is known as the yarn lead. The angle of this yarn lead is important and affects so many conditions that it cannot be changed with impunity.

In Figures 1 and 2 the dots 11 indicate the elevation of the tips or free ends of the open latches on certain of the needles N. As the butts 14 of the needles N ride up the left hand stitch cam 360 and the latches are cleared, the butt of the first needle N of the active group is caught in the lifter pick 650 and raised out of action to a position just above the flat top of the double stitch cam 50. Prior to lifter 650 reaching the dotted position shown above the stitch cam 50 in Fig. 1 it has pivoted in a horizontal plane radially away from the center of the cylinder as usual sufliciently to release the butt of the needle and this needle N continues at this elevation until raised to the full height of the rest of the inactive needles by raising cam 26 associated with the lowering pick or dropper 680.

Taking the situation at the moment shown in Figure 1, the needle N which is now left as the new leading needle of the active series, has moved along with its butt on top of the stitch cam 360, its latch cleared of the last loop and the bottom of the latch just below the floor of the throat plate 560 at the level 13. As the butt 14 (see Fig. 3) of needle N leaves the clearing and stitch cam 360, it meets the outside sloping surface 15 of the end of the double stitch cam. This surface lowers the needle till the bottom of the latch is at the level 16. The yarn lead 12 is coming in toward the observer of Figure 1 in a manner which brings it to a point of tangency at the needle N which has just been raised out of action. It will be seen that if the needle N were to move to the circumferential position in which the needle N is located and the bottom 11 of its latch were to remain at the level 16 where it was left by the sloping surface 15 of the double stitch cam, the latch might pass beyond, i.e., to the right of (above) the yarn lead 12 before the needle could be lowered sufliciently by cam surface 52 to prevent it passing beyond. Such an occurrence would cause the latch of the needle N to be closed by the yarn lead as the needle descended cam surface 52 and subsequently to clear the loop on its shank without drawing any new yarn through the loop and a dropped stitch would occur. This might also occur on the active needle following the needle N It will be noted that at this particular point in the knitting, the yarn from the throat plate 560 is switching from the left corner of the throat plate which it occupied during the stroke in the other direction to the right corner which it has reached in Figure 2. When it reaches the right corner the angle of the yarn lead is a little steeper than at the midpoint shown in Fig. 1 and it is when the yarn is leading from the corners that the correct yarn lead is established. In other words, for satisfactory knitting in either direction, the yarns should lead from the corner of the throat plate nearest the stitch cam on an angle low enough to ensure seizure by the hooks and high enough to prevent its being trapped by the closing latches. However, during reciprocatory knitting, the leading needle N and possibly the one following would start to descend cam surface 52 before the yarn reached the corner of the throat plate, and the problem of their latches closing without their hooks having taken yarn would still be present, resulting in drop stitches.

In order to free the machine from this possibility of dropped stitches, I bring the active needles to a lower level soon enough to prevent the latch tips 11 from passing above the yarn lead as the needle N approaches cam surface 52.

For providing cam means to position active needles at a lower clear level earlier than the stitch means, I have provided two cams 17, 18 partially lying in the notch 57 and in the notch 57 of the double stitch cam. These cams 17, 18 are shaped to engage the needle butts 14 before they reach the respective stitch drawing surfaces 52 or 51. The cams lower the needles to a level 19 at which the tips 11 of the latches cannot pass above the yarn lead 12.

The means for moving these auxiliary needle cams 17, 18 into and out of action are shown in Figure 4 of the drawings. The control is from the main pattern drum 120. A carn 501 on that drum raises a thrust bar 460 during the reciprocatory heel and toe knitting. The upper end of the thrust bar carries a length adjusting disc 20 connected to a bell crank lever 21 on the frame of the machine. The upper arm of the bell crank lever is pivotally connected to a horizontal rod 22 extending forward toward the needle cylinder above the bedplate B of the machine. Bolted to the end of the rod is a vertical pin 23 resting slidably on the bedplate. Fastened to the end of the horizontal rod is a bracket 24 extending laterally to the sides of the rod to positions in back of the auxiliary needle cams 17, 18. The connection between the bracket 24 and each cam involves a sliding spring-return bolt mounting 25. These enable the cams to be pushed in at the commencement of reciprocation and retracted at the end of a heel or toe. When the drum cam 501 raises the thrust rod 460, the two auxiliary needle cams 17 and 18 are inserted and when it drops off, the cams are retracted.

The retraction of the auxiliary needle cams during all rotary knitting enables the notches 57, 57 to be used for other purposes during the making of rotary parts of a stocking. In this connection it will be noted that I have shown a cam path in Fig. 1 for selected jacks to raise needles into the notch 57. These can be employed to produce, among other things, tapered high splice and cradle sole according to known methods. A similar cam path might also be provided for selected jacks to cause needles to be raised into notch 57 It will be noted that the notches face downwardly and have downwardly sloping outer edges so that needles approaching from the outside can be deflected under the edge. Similarly the inside is shaped to receive and lower needles raised into the notch for taking reinforcing yarn, etc., when cams 17, 18 are retracted.

The earns 26 and 27 located under the needle levelling asoas ts block 416 and on either side of the dropper or widening pick 680 serve to bring thelind'ividualneedles raised out ofaction to the full height of the inactive needles. On the reverse motion the cam 26 will function and in the counterclockwise or forward direction the cam 27 will act.

As shown in Figure 2, the chance of a drop stitch is also present at the second or. right hand feed when knitting begins at that point. However, due to the double stitch cam, the situation at the second feed on each reciprocation is different from that at the first feed.

As the first active needle N and those succeeding approach the bottom'of the stitch'cam surface 52, their hooks are drawing yarn, their latches are closing and they are knitting properly without risk of drop stitches at the first feed. As might be expected, the condition at the second feed is in many respects a repetition of the situation of the first feed in Figure 1. As seen in Figure 2, the yarn has not yet moved to the corner of the throat plate 561 nearest the stitch cam 361 and the needles are not yet coming down that stitch cam. Therefore the latches, if the needles had been raised to the normal clear height 16, would be too high to be out of danger of crossing above the yarn. However, since the needles at the second feed are raised rather than lowered to the desired height just prior to taking yarn, it is possible to obtain the desired result by elevating them only to what is known as the low clear level 19. Thus the needles can approach the low clear level from either above or below that level.

There is a movable clear cam 28 below the stitch drawing surface 51 of the double stitch cam. It extends laterally to a point below the wing containing the notch 57 This clear cam is vertically movable and if lowered to the height shown in the drawings, it serves to raise needles coming under the bottom of the double stitch cam to a height equal to the low clear level 19 to which the needles were lowered at the previous feed by the cam 17 in the notch. Similarly, in order to take care of the possibility of drop stitches when the needle cylinder is turning in the rundown or forward direction of rotation, a movable cam 29 is provided below the stitch drawing surface 52 on the other side of the double stitch cam. It can be lowered to low clear height to raise needles to level 19 in the same manner and for the same purpose as clear cam 28. Normally, the cams are at an elevation to raise needles to the level 16 'which, in the case of cam 29, delivers needles high enough for their hooks to seize the new yarn during a yarn change and to permit the needle cylinder to be raised for drawing longer stitches without danger of the latches failing to clear their stitches.

It will be seen that I not only provide a clearing cam 360 or 361 and a lowering cam 17 or 18 on each side of the double stitch cam 50 to participate in the knitting when ahead of the double stitch cam in either direction of knitting but another clearing cam 28 or 29 and either cam 360 or 361 adapted to act as a stitch cam after the double stitch cam 50, the lowering cams 17, 1'8 and the clearing earns 28, 29 being movable to and from positions at which they will deliver at least the leading active needle during reciprocating knitting to a level Where the latch cannot pass above the yarn making a drop stitch. At the same time this construction leaves the notch 57 clear during rotary knitting so that one or more needles may be raised for stitch variation in multi-feed knitting.

The operation for knitting in the forward direction will be obvious. If the direction of rotation of the needles is toward the left in Figures 1 and 2 the right hand feed becomes the first feed and the needles approach from the right of the figures. The butts of the active needles ride down the sloping outer edge 30 of the notch 57 at the right end of the double stitch cam as viewed in Figure 2. They then meet auxiliary cam 18 which lowers them to the low clear level 19 in the same manner as cam 17 did when the needles were moving in the other direction. At the second feed, i.e., the left-hand feed, the movable clearing cam 29 is in low clear position and elevates to this low clear level 19 all needles coming under the low point of the double stitch cam.

It may be argued that the trouble can be obviated by using yarn fingers which are not in the center of the throat plate (each throat plate has several fingers as usual). Unfortunately a finger may be advantageously off center and improve the yarn lead angle somewhat when the needles are moving in one direction but then its position will work to disadvantage when the needles are moving in the other direction.

From the foregoing description it will be seen that by use of the auxiliary cams and the notches in the wings of the double stitch cam in conjunction with the movable clearing cams, drop stitches may be avoided in narrowed and widened sutures, while on the other hand the auxiliary cams, when retracted, at other times, leave the openings or notches in the underside of the double stitch cams wings into which one or more needles selected by jacks, etc., may be raised for stitch variation in the multi-feed knitting of hosiery.

What is claimed is:

l. A circular hosiery knitting machine having independent needles with pivoted latches, at least one yarn finger and at least one throat plate from the edge of which the yarn can be fed tangentially and downwardly in a yarn lead to the needles, in combination with means to knit reciprocatorily for the making of narrowed and widened heel or toe pockets by moving needles out of and into action, regular stitch cam surfaces to draw stitches on active needles, and movable auxiliary cam means active during reciprocation, and While the yarn lead angle is changing, to position active needles at a level where the tips of their open latches are just above the partially formed stitches circumferentially ahead of the positions at which the regular stitch cam surfaces would cause the needles to reach said level; whereby the formation of drop stitches at or near the heel or toe suture is avoided.

2. A circular hosiery rnulti-feed knitting machine having independent needles with pivoted latches, at least two throat plates adapted to feed yarn from corners thereof tangentially and downwardly in a yarn lead, one or more yarn fingers in each throat plate, means to knit in a reciprocatory manner with narrowing and widening of an active segment of needles and switching of yarn from one throat plate corner to the other, in combination with regular stitch drawing surfaces at each feed and movable auxiliary needle cams associated therewith adapted to place the active needles at a level where the tips of their open latches are just above the partially formed stitches during switching of yarn from one throat plate corner to the other before the regular stitch drawing surfaces would have moved the needles to said level; whereby drop stitches in or near the narrowed and widened sutures are avoided.

3. A circular independent needle hosiery knitting machine adapted to knit multi-feed on both forward and reverse movements in which there is at least one double cam adapted to knit on both movements, a stitch cam lo cated ahead of said double cam on forward movements and active on those movements and a stitch cam located on the other side of the double cam active on the opposite direction of movement, a downwardly facing notch in each end of the double stitch cam, in combination with auxiliary needle cams located in the notches in the said double cam active only during reciprocation and adapted to place the active needles at a level where the tips of their open latches are just above the partially formed stitches before the double center cam contacts the needles; whereby drop stitches in or near the narrowed and widened heel and toe sutures are avoided and means to retract the said auxiliary needle cams to make the said notches available at other times for other needle manipulation.

- 4. In a circular independent needle knitting machine having a revoluble needle cylinder, adapted to knit multifeed on both rotary and reciprocatory movements of the cylinder, throatplates to present a lead of yarn to the needles at each feed tangentially to the cylinder and at an angle to the horizontal, a double stitch cam adapted to knit on cylinder movements in both directions, and a needle clearing cam surface and a lowering cam located on each side of said double stitch cam to participate in the knitting when the direction of movement of the cylinder is such that they are ahead of the double stitch cam, in combination with other clearing cams and lowering surfaces, some of which are positioned to act on the needles after the double stitch cam on one direction of movement and some on the other direction, at least two of said lowering cams and the last mentioned clearing cams being movable to and from positions at which they will deliver at least the leading active needle during reciprocator'y knitting when the angle of the yarn lead may vary, to levels where its open latch cannot pass above the lead of yarn at any feed which would otherwise prevent the yarn from being seized by the needle hook as it descends to knit at a feed.

References Cited' in the file of this patent UNITED STATES PATENTS Bellis Oct. 25, 1887 Lawson Apr. 27, 1948

Images