Textiles: knitting – Independent-needle machines – Circular
Reexamination Certificate
2000-07-10
2001-01-09
Worrell, Danny (Department: 3741)
Textiles: knitting
Independent-needle machines
Circular
C066S215000
Reexamination Certificate
active
06170299
ABSTRACT:
TECHNICAL FIELD AND BACKGROUND OF THE INVENTION
Circular knitting machines knit together multiple strands of yarn into a tubular fabric, hosiery blank or other structure. The hosiery blank is then finished according to conventional processes to create finished hosiery articles, such as socks, hose and stockings. Such machines include a plurality of needles positioned in axial slots formed in an exterior surface of a rotatable needle cylinder. Each needle includes a shank having opposed ends. A hook is formed in a top end of the needle shank and a butt is formed in the bottom end of the needle shank. A plurality of sinkers are mounted in a sinker ring positioned on a top end of the needle cylinder such that the sinkers are alternately positioned between the needles. Circular knitting machines also include a feeder mechanism that delivers yarn onto the passing needles. The yarn forms a loop or loop around each needle.
Hosiery articles with decorative patterns formed by open-work in the fabric created by transferred knitting loops is old and conventional. The space not occupied by the transferred loop creates a hole in the fabric, and the pattern of holes in the fabric collectively create the desired decorative effect. Heretofore such designs have been limited to relatively coarse gauge fabrics due to the difficulty in transferring very small loops between fine gauge needles. Thus, there is a need for a knitting machine and method which permits the creation of decorative open-work patterns in fine gauge knitted fabric, including fine gauge fashion hosiery, such as tights, pantyhose and similar articles.
For example, U.S. Pat. No. 3,838,583 to Rumi et al. discloses apparatus which modifies a circular knitting machine so that it can create openings with transfer loops. The Rumi apparatus includes a dial plate eccentrically positioned over and internal to a needle cylinder and a planetary gear eccentrically positioned over and external to the needle cylinder. The upper surface of the dial plate is provided with a plurality of internal punches slidable in a radial direction, and the upper surface of the planetary gear is provided with a plurality of external punches slidable in a radial direction. The internal punches are inclined suitably in the direction opposite of the direction of rotation. Devices are provided to control the axial movement of the internal and external punches and cam means are provided to raise the needles to the level of the punches. Finally, a plurality of movable sinkers are positioned on the needle cylinder and each partially surround one of the needles. The strands of yarn loop around the needles and extend over the sinkers.
In operation, the selectors raise a specified needle or group of needles past their normal working position. The loop on the needle catches on a needle shoulder which raises the loop above the sinker surrounding the needle. The sinker, which has an end hook, then advances and its hook enters the loop causing the loop to enlarge. Immediately afterwards, either of the two punches enter the loop by passing adjacent to an undercut in the needle. The needle is then returned to its normal position leaving the loop on the punch. The punch transports the loop to the intended needle which is raised up through the loop. That needle continues to rise until the loop is removed from the punch and then returns to its normal position. If the internal punch is used, the loop is transferred to the needle preceding the needle from which the loop was taken. If the external punch is used, the loop is transferred to the needle following the needle from which the loop was taken.
The Rumi apparatus, like other existing apparatus used for transferring loops, first removes the loop from the selected needle and then transfers that loop to the following needle. This practice can only be used effectively on circular knitting machines operating with one hundred and twenty (120) needles or less because the small size of the needles and loops on most circular knitting machines operating more than one hundred and twenty (120) needles prevents the apparatus from reliably transferring the loop. A missed transfer creates a defect which results in a less than first-quality product. The missed transfer problem is naturally exacerbated when the diameter of the needle cylinder is decreased and/or the number of needles being operated is increased.
Consequently, transfer loops cannot be reliably made on prior art fine gauge circular knitting machines. A need, therefore, exists for a method and apparatus for effectively transferring loops from a selected needle to an adjacent needle without dropping a loop and without creating other defects in hosiery articles manufactured on a circular knitting machine capable of creating fine gauge articles.
SUMMARY OF THE INVENTION
Therefore, it is an object of the invention to provide a method and apparatus for reliably transferring loops to create hosiery having a pattern of small openings which collectively create a decorative appearance to the fabric. Unlike existing methods and apparatus, the present invention enables open-work patterns to be formed in very fine gauge hosiery created on, for example, circular knitting machines operating 120 or more needles positioned on a needle cylinder having a diameter of 3.5 inches or less. The invention is capable of being used on any gauge machines with as little as 1 mm spacing between needles.
Accordingly, a principal object of the present invention is to provide a method for virtually error-free transfer of a loop from a selected needle to a following needle on a circular knitting machine, including but not limited to a fine gauge circular hosiery knitting machine, such as one having 120 or more needles positioned on a needle cylinder having a diameter of 3.5 inches or less.
A further object of the invention is to provide a method of or transferring a loop from a selected needle to a following needle by securing the loop on the following needle before the selected needle releases the loop.
A further and more particular object of the invention is to provide a method and apparatus for transferring a loop from a selected needle to a following needle by widening the loop on the selected needle, inserting the following needle through the widened loop, and only then removing the selected needle from the widened loop thereby causing the selected needle to release the loop.
Another object of the invention is to provide an apparatus for performing the transfer loop operation.
Another object of the invention is to provide enlarging means and cam means for performing the transfer loop operation.
Another object of the invention is to provide means for adapting a common circular knitting machine by inclusion of the invented apparatus to minimize manufacturing cost, to guarantee reliable operation, and to avoid the necessity of requiring operator re-training.
The method according to the invention involves transferring a loop from a selected needle to a following needle during the operation of a circular knitting machine. As used herein, a selected needle is a needle from which the transfer loop is removed, and a following needle is an adjacent needle onto which the transfer loop is placed. It is contemplated by the present invention that the following needle may be either the needle immediately preceding the selected needle with respect to the direction of needle cylinder rotation or the needle immediately succeeding the selected needle with respect to the direction of needle cylinder rotation.
To perform the transfer loop operation, the loop on the selected needle is enlarged or widened. Once the loop on the selected needle is sufficiently enlarged, the following needle is inserted through the enlarged loop such that the loop may then be secured around the following needle. Finally, the selected needle is removed from the enlarged loop thereby causing the selected needle to release the loop. As a result, the loop is completely transferred from the selected needle to the following needle and a controlled pe
Adams, Schwartz & Evans P.A.
Edelweiss Manufacturing Co., Inc.
Worrell Danny
LandOfFree
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