US3013417A - Knitting machine stitch length control - Google Patents

Description

o. w. HOLDER 3,013,417

KNITTING MACHINE STITCH LENGTH CONTROL 2 Sheets$heet 1 Dec. 19, 1961 Filed Jan. 13, 1959 N 1 I 10 m N N INVENTOR:

| 0115 W. HOLDER.

"' BY g agwrw A'ITORNEY5 Dec. 19, 1961 o. w. HOLDER 3,013,417

KNITTING MACHINE STITCH LENGTH CONTROL Filed Jan. 13, 1959 2 Sheets-Sheet 2 W42. 5 9O S 74' INVENTOR. O'ns W. HOLDER Y z% MM+% ATTORNEYS n t States Patent 3,013,417 MAC STITCH LENGTH CONTROL Otis W. Holder, Mount Airy, N.C., assignor to Patent- Hose Corporation, Burlington, N.C., a corporation of North Carolina Filed Jan. 13, 1959, Ser. No. 786,634 5 Claims. (Cl. 66-54) This invention relates generally to a novel mechanism and method for regulating the length of stitches formed by the needles of a circular independent needle hosiery knitting machine.

For many years the stitch length has been controlled by varying the relationship between the needle cylinder and the stitch forming cams and this system is presently used by the two most popular types of circular independent needle knitting machines. In Scott & Williams machines, as shown in United States Patent No. 1,152,850, dated September 7, 1915, the needle cylinder is raised and lowered by pattern control means to raise and lower a tube positioned in alinement below the needle cylinder while maintaining the stitch forming cams in a stationary position. In Hemphill machines, as shown in United States Patent No. 933,443, dated September 7, 1909, the stitch forming cams are raised and lowered by pattern control means while maintaining the needle cylinder in a stationary position. By changing the vertical relationship between theneedle cylinder and the stitch cams, the depth to which the needles are drawn each time that the butts thereof are lowered by the stitch cams is also changed to thus control the length or size of stitches drawn by the needles.

In both of these types of knitting machines the needles are carried for independent vertical movement in the needle cylinder and when the relative position of the needle cylinder and the stitch forming cams is changed, the normal path of travel of the butts is also changed. Thus, the vertical position of needle butts passing through and about to enter the stitch cams will be changed when the stitch length is changed by imparting relative movement between the needle cylinder and the stitch cams. If the vertical position of the needle butts, in relation to the stitch cams, is changed too drastically, the butts will engage the ends of the stitch cams and be broken 01f instead of engaging the inclined surfaces and being raised or lowered. In both of the present types of knitting machines, it is impossible to suddenly increase or decrease the size of stitch being drawn by vertical movement of either the needle cylinder or the stitch drawing cam without breaking the butts of needles.

The types of stitch regulating mechanisms presently in use are limited to a gradual increase and decrease in stitch length regulation and are also limited to a relatively narrow range of stitch length regulation. The range of stitch length regulation is limited when vertical movement is imparted to the stitch cams because the relationship between the hooks of the needles and the yarn feeding point is changed and the yarn will not be fed to the needles at the desired position. Because the conventional knitting machines are limited to a narrow range of stitch length regulation and to a gradual change in stitch length adjustment, several methods have been proposed for modifying these machines to provide auxiliary means for drawing unusually long stitches. One method includes changing the radial movement of the sinkers so that they are moved in earlier than usual whereby the yarn will be fed over the nibs thereof to thus form longer than usual stitches. However, when drawing longer stitches by knitting over the nib or high portion of the sinker, the sinkers cannot carry out their usual function of holding down the fabric and this frequently results in smash-ups and an accumulation of fabric, thus causing broken needle hooks, latches, butts and the like.

In some cases the machines have been modified to include means to raise the inner ends of the sinkers when yarn is fed to the needles and stitches drawn to thus increase the amount of yarn present in each stitch loop. The sinkers are usually positioned horizontally and when the inner ends of the sinkers are raised it is extremely diflicult to accurately control their radial position and maintain the same at a fixed level.

With the foregoing remarks in mind, it is the primary object of this invention to provide a novel mechanism and method for regulating the stitch length of a circular knitting machine within a wide range of regulation while maintaining the sinkers in a horizontal position and moving them radially in a conventional path.

It is another object of this invention to provide a stitch regulating mechanism which may be operated to quickly change the length of stitch being formed from a very short stitch to a very long stitch and vice versa without changing the vertical relationship between the needle cylinder and the stitch cams.

It is another object of this invention to provide an improved stitch regulating mechanism for controlling the length of stitch formed by circular knitting machines whereby the operation of the regulating mechanism will not change the operating relationship of the needle cylinder and stitch cams and thereby reduce needle butt breakage.

It is another object of this invention to provide a stitchregulating mechanism which is controlled by the usual pattern control mechanism of the knitting machine and which is operative to vary the relative position of the sinkers to the hooks of the needles while maintaining the same operative relationship between the path of travel of the needle hooks and the yarn feeding fingers as well as between the path of travel of the needle butts. and the stitch cams.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings, in which FIGURE 1 is a fragmentary left-hand side elevation of a circular knitting machine with parts broken away for purposes of clarity and with the present invention applied thereto;

FIGURE 2 is an enlarged vertical sectional view through the upper portion of the machine, taken substantially along line 22 in FIGURE 1;

FIGURE 3 is an enlarged fragmentary viewof the right-hand portion of FIGURE 2 with the central portion broken away and showing the' relationship of the sinkers and needle cylinder when the machine is forming regular or short stitches;

FIGURE 4 is a view similar to FIGURE 3 but showing the relationship of the sinkers and needle cylinder when the machine is forming long stitches;

FIGURE 5 is a horizontal sectional view at a reduced scale and being taken substantially along the line 55 in FIGURE 2 (at a reduced scale).

Referring to the drawings, it will be noted that the present stitch regulating control is illustrated as being applied to a Scott & Williams type plain knitting machine and it is to be understood that this mechanism could also be applied to Hemphill type machines and to other .types of Scott & Williams machines, such as those havof a mating bevel gear 12 mounted for rotation in a cam bed plate 13. The cam bed plate 13 is suitably supported on the frame and supports a latch ring pivot post 14 (FIGURE 1) and a widening pick stand 16 as well as the usual needle cams and stitch cams 17 positioned around the needle cylinder 20.

The outer surface of the needle cylinder 20 is provided with a plurality of grooves which extend vertically and receive latch needles N for vertical sliding movement therein. The lower surface of the cam bed plate 13 is provided with a downwardly extending flange 25 in which the upper end of a tube 30 is mounted for vertical sliding movement. The tube 30 is commonly known as a cylinder raising tube but which in this instance will be called a sinker raising tube for purposes to be later explained. The lower end of the sinker raising tube 30 is suitably mounted for vertical movement in a bracket carried by the frame 10 in a conventional manner, not shown.

The sinker raising tube 30 is provided with a support bracket 31 which is fixed on the tube 30 and which is normally supported on the upper end of a screw 32 threadably supported at its lower end in an arm of a stitch length adjusting lever 33. One end of the lever 33 is oscillatably mounted on a shaft 34 and the other end of the lever 33 is supported on suitable cams, not shown, fixed on a main pattern drum 35. The pattern drum 35 is mounted for rotation in the frame 10 on a shaft 36 and is driven in a step-by-step manner through conventional gearing under control of the main pattern chain, not shown.

The main pattern drum 35 also controls other conventional parts of the knitting machine, such as thrust rods 40 which extend upwardly therefrom and control the operation of yarn fingers 41 mounted in a latch ring 42. It will be noted in FIGURE 1 that the rear portion of the latch ring 42 is pivotally mounted on the upper end of the post 14 as at 43 and the front portion is supported on the upper end of the stand 16. The knitting machine is also provided with a sinker head, broadly indicated at 50, which is spaced below the latch ring 42 and supported in a manner to be later described. A sinker head hold-down arm 52 is suitably secured at its lower end to the sinker raising tube 30 and its upper end extends over the sinker head 50 and engages the same to hold the sinker head 50 in fixed relation with the sinker raising tube 30.

The parts heretofore described are conventional parts of a Scott & Williams type knitting machine and it is with this type of machine that the present invention is illustrated, although it is to be understood that this invention may be applied to other types of knitting machines. In the conventional knitting machine of this type, the sinker head 50 is fixed on the upper end of the needle cylinder 20 and the needle cylinder 20 is mounted for vertical movement on an upstanding sleeve which is integral with the gear 12. Vertical movement of the sinker head 50, to vary the length of stitch drawn by the needles N, is effected by pins which are mounted for vertical sliding movement through the gear 12. The upper ends of these pins engage the lower surface of the needle cylinder 20 and the lower ends of the pins are supported on the upper end of the tube 30. Thus, when the sinker raising tube 30 is raised or lowered, the needle cylinder 20 will be correspondingly raised and lowered on the gear sleeve to thus raise and lower the sinker head 50.

Since the needle cylinder 20 must be moved vertically in order to raise and lower the sinker head 50, the needles N carried by the needle cylinder 20 will also be moved vertically thereby changing their normal relationship with the stitch cams, which remain stationary. The operating butts of the needles N follow a certain path of travel through the stitch cam and any drastic vertical movement of these needle butts will cause the butts to be raised or lowered so that they do not properly engage the stitch cams and are broken.

By the use of the present invention, it is not necessary to raise or lower the needle cylinder 20 in order to raise or lower the sinker head 50 and change the stitch length. In the present invention, the lower end of the needle cylinder 20 is fixed to the bevel gear 12 as by screws 55 (FIGURES 2, 3 and 4) so that the needle cylinder 20 will at all times remain in a stationary vertical position and thus, the needles N will always maintain the same relationship with the stitch cams 17 and the yarn feeding fingers 41.

In the present instance, the upper end of the sinker raising tube 30 is provided with a bearing ring 56 on which the lower end of a sinker support sleeve 57 is supported for rotation. The upper end of the sleeve 57 has an enlarged annular flange 60 formed integral therewith and having suitable radial grooves or slots 61 in vertical alinement above the needle slots in the needle cylinder 20 to provide a passageway for the needles N therethrough (upper right-hand portion of FIGURE 2). The outer periphery of the flange 60 supports a sinker bed 65 which is removably secured to the flange 60 by set screws 66 adapted to bear against the outer ends of pins 67. The upper surface of the sinker bed 65 is provided with radially extending sinker grooves or slots 70 for slidably supporting the outer ends of sinkers S. The inner ends of the sinkers S are supported for radial sliding movement in the grooves of a sinker ring 72 which is suitably fixed on the upper inner surface of the sleeve 57.

A sinker cap 74 holds the sinkers S in the sinker bed 65 and ring 72 and has conventional sinker operating cams, not shown, which cause the sinker to move inwardly and outwardly in the sinker bed 65 and between the needles N as they pass through the knitting wave, in a conventional manner. The front portion of the sinker cap 74 is provided with cars 75 (FIGURE 1) which are adapted to abut against opposite sides of the upper end of the stand 16 to prevent rotation of the sinker cap 74.

Relative rotation between the sleeve 57 and the needle cylinder 20 is prevented by a key which is fixed in the sleeve 57 and engages a keyway 81 cut in the inner surface of the needle cylinder 20. Thus, when rotation or reciprocation is imparted to the bevel gear 11, like motion will be imparted to the bevel gear 12, needle cylinder 20, sleeve 57 and sinker bed 65 so that the needles N and sinkers S rotate or reciprocate in a conventional manner. The sinker cap 74 will remain in substantially a stationary position and the sinker cams carried hereby will control radial or inward and outward movement of the sinkers relative to the needles N.

In order that the sinker head 50 may be lowered to a position below that shown in FIGURES 2 and 3, the flange 60 of the sleeve 57 is undercut as by an annular groove 85. Thus, if the sleeve 57 is lowered far enough, the upper end of the needle cylinder 20 can extend into the annular groove 85. The sinker head hold-down arm 52 insures that any vertical movement imparted to the tube 30 will also be imparted to the sinker head 50 since the lower end of the arm 52 is attached to the tube 30 and the upper end of the tube 30 bears down against the upper surface of the sinker head 50.

In the present invention, it is not necessary to vertically move the needle cylinder when the stitch length is being regulated and therefore the operating butts of the needles N maintain their usual relationship with the stitch drawing cams. Thus, the stitch cams always draw the needles down the same distance regardless of the side stitch loops being formed while the size of the stitch loops is controlled by raising or lowering the sinker raising tube 30 by means of cams on the main pattern drum 35 and the stitch regulating lever 33.

As is well known, the hooks of the needles N receive the yarn from the yarn feeding fingers 41 and the needles are lowered by the stitch cams so that stitches are formed over the throat portion 90 of the sinkers. If the sinkers are raised, more yarn will he used in each stitch loop drawn by the needles and conversely, if the sinkers are lowered, less yarn will be used in each stitch loop. Relatively short stitch loops will be formed when the sinker head 51' and sinkers S are lowered to substantially the position shown in FIGURE 3 and relatively long stitch loops may be immediately formed by raising the tube 30 and the sinker head 50 to substantially the position shown in FIGURE 4. Of course, the sinker head 50 may also be positioned at any intermediate position or may be gradually moved from one position to another by the use of a conventional graduating mechanism, not shown, to change the length of stitch loops being formed without upsetting the relationship of the needle operating butts and the stitch drawing cams surrounding the needle cylinder.

As has heretofore been stated, this invention may also be applied to a Hernphill type machine wherein the length of stitch is regulated by vertical movement of the stitch cams while the needle cylinder is held in a stationary position. The same problem is present in this type machine because there is relative movement between the butts of the needles carried by the needle cylinder and the stitch cams and vertical movement of the stitch cams will change the operating relationship of the butts of the needles N and the stitch forming cams. In Hemphill type machines, the sinker head normally is fixedly secured to the upper end of the needle cylinder and in order to apply the principles of this invention to a Hemphill type machine, it would be necessary to secure the stitch cams in a fixed position relative to the needle cylinder and independently support the sinker head.

Although the problem of stitch length control has long been present in circular knitting machines, particularly where drastic stitch length regulation is required, there has been no practical solution to this problem prior to this invention. The present invention is the first to recognize the importance of maintaining the same relationship between the operating butts of the needles and the stitch cams surrounding the needle cylinder while also maintaining the same relationship between the hooks of the needles and the yarn feeding fingers. In the present invention, the positions of the needle cylinder, yarn feeding fingers and stitch cams have been fixed relative to each other and the length of stitch loops is controlled by the height of the sinkers above the needle cylinder. Thus, the length of stitch loops may be controlled without changing the operating relationship between the needles and the stitch cams or between the needles and the yarn feeding fingers.

In the drawings and specification there has been set forth a preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

1. In a circular knitting machine having a rotatable needle cylinder, vertically movable needles carried by said cylinder, and a sinker head encircling the upper ends of i said needles, stitch length control means comprising support means for supporting said sinker head independently of said needle cylinder, and pattern control means for elfecting relative vertical movement between said needle cylinder and said sinker head during knitting.

2. In a circular knitting machine having a rotatable needle cylinder, vertically movable needles carried by said cylinder, and a sinker head encircling the upper ends of said needles, stitch length control means comprising support means for supporting said sinker head independently of said needle cylinder, and pattern control means operatively connected to said support means for varying the position of said sinker head relative to said needle cylinder during knitting.

3. A method of controlling the length of stitches formed by a circular knitting machine having a rotatable needle cylinder, vertically movable needles carried by said cylinder, and a vertically movable sinker head encircling the upper ends of the needles which comprises the steps of rotating the needle cylinder to form stitch loops of a predetermined length on the needles, increasing the length of stitches drawn by the needles by raising the sinker head relative to the needle cylinder, and decreasing the length of stitches drawn by the needles by lowering the sinker head relative to the needle cylinder.

4. A method of controlling the length of stitches formed by a circular knitting machine having a rotatable needle cylinder, vertically movable needles carried by said cylinder and a vertically movable sinker head encircling the upper ends of the needles which comprises the steps of rotating the needle cylinder to form stitch loops of a predetermined length on the needles, and then lengthing and shortening the stitches drawn by the needles by correspondingly raising and lowering the sinker head while maintaining the rotating needle cylinder in a fixed axial position.

5. A method of controlling the length of stitches formed by a circular knitting machine having a rotatable needle cylinder, vertically movable needles carried by said cylinder and a vertically movable sinker head encircling the upper ends of the needles which comprises the steps of rotating the needle cylinder to form stitch loops of a predetermined length on the needles, and then varying the size of stitches formed by the needles by correspondingly changing the vertical relationship between the needle cylinder and the sinker head.

References Cited in the file of this patent UNITED STATES PATENTS 679,281 Kilbourn July 23, 1901 726,178 Mayo Apr. 21, 1903 1,131,583 Wilcomb Mar. 9, 1915 1,782,298 Grieve Nov. 18, 1930 1,817,116 Williams Aug. 4, 1931 1,977,522 Mills Oct. 16, 1934 2,069,155 Lawson Jan. 26, 1937 2,142,693 Lawson et al. Jan. 3, 1939 2,534,460 Lawson et al Dec. 19, 1950

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