US2090500A - Method of knitting - Google Patents

Description

1937. R. H. LAWSON METHOD OF KNITTING Filed Feb. 19, 1935 2 Sheets-Sheet 1 [NYE/V7019. iE'oazznfal mmg 51V f yfivflf Aug. 17, 1937. R. H. LAWSON METHOD OF KNITTING 2 Sheets-Sheet 2 Filed Feb. 19, 1935 fA/VENTflR: 18035375 15/! III 301g Byif QM 07 A2736 Patented Aug. 17, 1937 UNITE STATES PATENT oFFmE 2,090,500 METHOD OF KNITTING Application February 19, 1935, Serial No. 7,248 In Canada November 24, 1934 3 Claims.

This case deals with a particular method of drawing knitted stitches when both the needles and sinkers are given simultaneous movements for the purpose of forming a stitch. The case has to do especially with a particular method of timing the action of both needles and sinkers so that full benefit of theconjoint action of needles and sinkers will be realized. One purpose of this particular method of timing is to form each stitch individually without disturbing any stitch or stitches which have been drawn previously, another to impose a minimum of strain upon the yarn which is being operated upon by the knitting instrumentalities.

In the drawings: I

Fig. 1 is a somewhat diagrammatic view showing several needles and sinkers in their relative positions as they are forming loops at the knitting point, certain cams are shown in section;

Fig. 2 is an enlarged view of a needle, sinker and sinker jack such as are used for drawing stitches in the manner disclosed in this case;

Fig. 3 is a plan view showing a few needles and sinkers such as have been shown in Fig. 2; and

Figs. 4, 5, and 6 are sectional views, greatly enlarged, showing progressive steps of the forming of a stitch; for purposes of clearness, the fabric which is already upon the needles is not illustrated.

It has long been realized that certain advantages could be gained if both the needles and sinkers of circular knitting machines could be used to draw knitted stitches with a combined stitch drawing movement. In general, this method consists in moving the needle downwardly as is the usual practice, and at the same time, moving the sinker or similar instrumentalities upwardly or at least in the opposite direction of that in which the needle was moved. With the mechanism herein shown and described it was possible to actually knit fabric on a production basis and to make fabric which was superior to the usual product of circular knitting machines. However, a new problem presented itself, this problem being peculiar to machines such as that disclosed herein where each knitted loop is formed by the combined and substantially simultaneous movement of needles and sinkers. This problem involved the timing of the cooperating needle and sinker movements. Yarn breakage caused by strain on the same as it was being kinked into permanent loops was a factor which seriously impaired the eificiency of the machine until this peculiar timing with its advantages was discovered. After the adoption of the needle and sinker timing as herein described yarn breakage and cutting at the sinkers has been practically unknown.

Referring to Fig. 1 a series of sinkers I are shown spaced between a plurality of latch type needles 2. These needles and sinkers are cooperating to draw knitted stitches of a yarn 3 which is being fed in the proper relation to said needles by a yarn guide indicated at 4. It is not necessary that the needles be of the latch type although latch needles are used in this case for purposes of illustration. The needles are provided with butts 5 at their lower ends which engage cams 6 and 'l to be guided thereby in their yarn taking and stitching drawing movements. The sinkers, better shown in Fig. 2, have nibs, throats and stitch drawing edges which are of somewhat conventional form and each sinker extends rearwardly to terminate in a butt 8 which, in cooperation with certain cams (not shown), give the sinker its radial movements. Each sinker is adapted to be swung about a pivot point 9 by means of a sinker jack I 9 which engages a projection I I on each sinker. Each jack has two offset lugs l2 and I3 which thru their engagement with projection I! serve to control the movement of the sinker in exact accordance with the contour of cams l4 and l 5 which engage butts l6 on the jacks. While it is not necessary, the jacks are preferably arranged to slide within the same tricks in which the needles slide and outside of said needles.

Referring to Fig. 4 there are shown portions of four needles and three sinkers. Needle I1 is in its lowermost position while the sinker I8 is in its uppermost position and the stitch which has been drawn by this needle and sinker is completely formed and will suffer no further distortion or change in form except to be slightly relieved as to the tension therein by a small upward movement of the needle accompanied by a cooperating downward movement of the sinker, also of slight extent. Needle H] has also been drawn downwardly by cam 5 until it has reached its extreme lower position. However, sinker 20 which has cooperated in the drawing of the stitch which extends between sinkers l8 and 29, held in the hook of needle 19, is not yet at its uppermost elevation. This sinker will be raised a slight amount until it reaches the same elevation to which sinker l8 was raised, Fig. 5, whereupon the stitch will be completed.

' In theory, the timing of needle l9 and sinker 20 which are herein taken for example might be such that needle I9 would reach a bottom point of earn 6 and sinker 20 would reach the uppermost extent of its travel'at precisely the same time; such a method of timing would be ideal.

Due. to the impossibility of obtaining perfection in the mechanism which has been shown, it would not be mechanically possible to realize this ideal condition. If one were to attempt such a method of timing it would be found that'certain sinkers would closely approach the ideal which was being aimed at, while those re'mainingwould probably vary slightly on either side of the condition desired so that some would lag behind theneedles while others would precede their cooperating needles and would reach their uppermost positionbefore the needles reached their lowest position. It has been found that this last condition is one which can not be tolerated, and to make such operation of sinkers with respect to their needles'impossible, the timing has been modified to make each needle' descend to its lowermost point before the corresponding sinker has quite reached its highest elevation.

The next needle 2| will then engage the yarn prior to this last movement of sinker 20 but there will be no particular disadvantage experienced since the yarn may-be very easily drawn through the hook or one needle. If the opposite should prevail, i. e.,' needle I9 be forced to descend slightly after sinker 20 has reached its uppermost position it would be necessary for that needle to reeveyarn over sinker 20 and also through the hook of needle 2i. It is this last condition which was responsible for imposing excessive strain upon the knittingyarn and breaking the same very frequently as it was drawn over the top of said sinker. Fig. 6 illustrates a step slightly farther in ad- Vance wherein sinkers l8 and 2B and needle l9 have continued on with their completely drawn loop'and have probably started to relievethe tension of that loop slightly. Needle 2l has descendedand sinker 22 has risen until it is now in contact with the yarn which is coming from the supply. It can be seen from this figure that the needle has made more than half of its stitch drawing movement at this time, and that the sinker will make the greater part of its upward movement after it has engaged the yarn and also draw much the greater portion of the yarn which enters into the loop. The cycle will be continued with respect to needle 2 l and sinker 22, the needle reaching its lowermost position prior to complete elevation of the sinker. While the needle engages the yarn first, it has an easier movement than the sinker so that in the actual formation of a stitch thesinker does a greater portion of the work and does it in a smaller time interval.

In Fig. 1 the needle butts may be seen descending under the action of cam 6 in Fig. 1 and the butts I6 of sinker jacks 10 may be seen in that same figure as they are moved upward more abruptly'by cam I 4. It is necessary to so position these cams 6 and I4 that the jack which raises the cooperating sinker for any particular needle will not quite reach the tip or highest point 7 on cam 14 as the corresponding needle reaches the extremelower point of cam B. The surface M of the sinker jack cam has a slight downward slope sothat the sinkersmay slack off slightly for relieving the tension of stitches which have been drawn. Cam I is provided with a surface I which functions after the needles have reached their lowest position under the action of camfli, to raise those needles just enough to relieve 'of the appended claims.

stitches thereon. These means for relieving stitches may be used separately or in conjunction with one another.

In the foregoing description it has been stated that the ideal condition would be for the needles, such as the needle I9 and the companion sinkers or other instrumentalities such as 20, to complete their stitch drawing movements in opposite directions at substantially the same time, but that complete realization of this condition was practically impossible and that a completion of the upward movement of the Sinker or other'instr'umentality such as 20 prior to the completion of the downward movement ofthe companion nee-' die 19 resulted in yarn breakage. 'It is also stated in the foregoing description that in order to overcome breaking of the yarn, the upward movestrain upon the yarn (the final drawing of the stitch by the further downward -movement of the needle being effected while the companion sinker such as 20, Fig. 4, is ata lower level as compared with the sinker 3 shown at the right of'the said needle [9, Fig. 4)' than Wouldbe the case if the sinker andneedle complete theirstitch drawing movements at substantially the same time. a

i The invention has been described relative to particular embodiment of the mechanism which 'has been employed, but itis not intended to create the impression thatthe invention islimlted V in such respects as it is the principle involved, the concept of timing to obtain a successful operation of both needles and sinkers to draw stitches, which it is desired to protect. The invention is not to be limited except by the scope .I claim:

1. A method of drawing stitchesby the cooperative movements in opposite directions of nee- V dles and other instrumentalities such as sinkers, including a downward or other movement of a needle, drawing yarn from the source of supply before the sinker-like instrumentality engages the yarn, continuing the movement of the'needle in the same direction as before and moving the sinker-like instrumentality in a direction opposite to the direction of movement of the needle, the last mentioned movement of the needle be ing substantially less than the movement of the sinker or other instrumentalityduring which movements of the needle and sinker-like instrumentality the yarn is engaged and drawn both by the needle'and' by the sinker-like instrumentality although the amount 'of yarn drawn by the needle is materially less thanthe amount of yarn drawn by the sinker or other instrumen tality..

. 2. A method of drawing knitted loops by the conjoint-action of needles and sinkers moving in opposite directions and drawing yarn from a source of supply, each'stitch being substantially completedprior to the start of drawing the next succeeding stitch, each needle being timed to reach its extreme position slightly in advance of the cooperating (succeeding) sinker reaching its extreme extent of travel in the opposite direction.

3. A method of drawing knitted loops by the conjoint action of needles and cooperating instrumentalities in a sinker head, said instrumentalities cooperating in the drawing of stitches by moving in a direction opposite to the stitch drawing movement of the needle, each needle and instrumentality cooperating and functioning independently to draw individual stitches and substantially complete the drawing of a stitch before the next following needle and instrumentality start the drawing of another stitch, including the step of controlling the timing of each needle and instrumentality which cooperate in the knitting of a stitch in such a manner that the needle will reach its extreme stitch drawing position slightly before the cooperating instrumentality completes its stitch drawing movement in the opposite direction.

v ROBERT H. LAWSON.

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