US2408698A - Knitting machine and method of knitting - Google Patents

Description

Oct. 1, 1946.

N. H. SMITH mun-Ins lmcnnm Am) METHOD 'oF mum-me Filed Oct. 21, 1944 [Mm/Tar: MJPMHH 5H1] Patented Oct. 1, 1946 KNITTING AND METHOD OF KNITTING Norman H. Smith, Pawtucket,

Hemphill Company, Central Falls,

R. 1., assignor to R. 1.,- a cor-'- poration of Massachusetts I Application October 21, 1944, Serial No. 559,775

' 4 Claims. (01. 66-14) This invention relates to a new and useful improvement in knitting machines of the type having two axially opposed needle cylinders and to a method of knitting upon this type of machine. More specifically, this invention relates to sinkers associated with the lower cylinder and adapted to cooperate with the needles in the drawing of yarns and to a novel manner of operating these sinkers to carry out the method.

Two cylinder machines of this type are widely employed for knitting true rib fabric and also knitting a combination of true rib and plain fabric. For the knitting of plain fabric the lower cylinder only is utilized and sinkers are associated therewith to enable the needles to draw yarn and to knit loops.

Heretofore the yarn has been drawn in the throats of the sinkers. The result of this is that when the sinkers move to cast off knitted loops from the needles they necessarily act not only upon the knitted loops but also upon the yarn which has just been drawn. This yarn is comparatively unstable at this time so that any lack of uniformity in the sinkers or the needles or in their actual or relative motions is reflected in the lengths of the loops. Also there is likely to be a lack of uniformity in the shapes of the loops, one side differing from the other or whole loops tilting from the perpendicular.

By the method of'this invention the loops are drawn over the backs of sinkers behind the nibs on a surface having a definite height. Thereafter the loops are transferred from the backs to the throats of the sinkers overthe tops of the nibs. In this way, the casting off is accomplished by the sinkers acting upon the completed and comparatively stable loops of the preceding course. The newly drawn loops, being on the backs of the sinkers behind the nibs and able to move freely upon them, take no part in the casting off operation and are unaffected thereby.

Also when the sinker loops pass over the nibs on their way to the throats of the sinkers they are stretched slightly so that the adjacent needle loops are tightened around the needles. This has an equalizing effect upon the needle loops. When the needles go down to knit the sinker loops undergo a similar equalizing experience as the needle loops are stretched by their passage over the enlargedportion of the needles adjacent the latch pivots.

All of these things, particularly thecasting off of needle loops by the action of the sinkers upon the sinker loops only, cause improvement in the quality of the fabric as a whole and of the individual loops whichis very marked.

1 One'form of the invention is shown in the drawing of which:

Fig. 1 is an elevation largely in section of a part of a two cylinder knitting machine showing the upper end of the lower cylinder, a needle arranged to operate therein, a sinker and the sinker cam;

Fig. 2 is a similar view showing the needle and sinker in a different position; and

Figs. 3 and 4 are views illustrating the method of knitting in which the yarn is drawn over the backs of the sinkers.

In Fig. 1 the upper end of the lower cylinder is shown at l. Affixed to this is an arcuate sinker guide 2 upon which an arcuate sinker 3 is adapted to rock radially of the cylinder. The rocking of sinker 3 is controlled by a cam 4 having a cam track 5 of appropriate shape to rock sinker 3 in the desired directions and to the desired extent at the desired times.

In order to draw the yarn over the backs 6 of the sinkers the sinkers are moved in soon enough and far enough for the purpose. This is shown in Fig. 1, the newly drawn sinker and needle loops being indicated at l and 8, respectively. As will be seen, the corresponding sinker loop 9 of the preceding course is in the throat of the sinker. Consequently, when the sinkers move in still further to cast off the adjacent needle loop 10 it will act upon sinker loop 9 only, the newly drawn sinker loop 1 upon the back 6 of the sinker being unaffected. To insure sinker has no effect upon loop l, back 6 is shaped to an arc concentric with the are through which the sinker rocks.

Fig. 2 shows a, further step in the knitting operation after the needle has risen again. The new needle loop 8 has now moved from thehook to the shank of the needle but the adjacent sinker loop 1 is still over the back of the sinker.

Fig. 3 also illustrates this condition, two sinker loops 1 being shown over cent sinkers and around the shank of the intervening needle H. Loops 9 are in the throats of the sinkers, the needle loop [0 having been previously cast off.

Fig. 4 illustrates a further step in the method of knitting in which the sinkers have been moved out so that the new sinker loops 1 have been transferred from the backs to the throats of the sinkers over the tops of the nibs prior to drawing more yarn over the backs of the sinkers for another course.

This method of knitting is hardly necessary for that this motion of the g the backs of two adjathe comparatively heavy coarse gauge fabrics ordinarily produced upon two cylinder independent needle knitting machines but is practically essential for the production of fine gauge fabric of the highest grade and for securing the best possible plating and wrap patterns. Drawing the yarns or yarn over the backs of the sinkers makes it possible to apply methods for plating and for the production of wrap patterns which cannot be taken advantage of when the throats of the sinkers are used and which are essential the adjacent sinker loops only and transferring the newly drawn loops from the backs to the throats of the sinkers over their nibs.

2. For a knitting machine of the superposed, co-axial cylinder, independent needle type, a sinker adapted to move in an arcuate path relative to the cylinders and having a yarn drawing surface behind the nib shaped to an arc concentric with said path.

3. For a knitting machine of the superposed, coaxial cylinder needle type, a sinker adapted to swing about a center and having a yarn drawing surface behind the'nib shaped to an are concentric with said center.

4. For a knitting machine of the superposed, coaxial cylinder needle type, a sinker adapted to swing in a vertical plane about a center and having a yarn drawing surface behind the nib so shaped that every point when positioned to be contacted by a yarn will be at the same height with respect to said cylinder.

NORMAN H. SMITH.

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