US2013883A - Loop forming mechanism for straight knitting machines - Google Patents

Description

Sept. 10, 1935.

5 Sheets-Sheet 1 Filed April 20, 1935 Firs-J" INVENTOR:

A TTORNEY G. GASTRICH Sept. 10, 1935.

LOOP FORMING MECHANISM FOR STRAIGHT KNITTING MACHINES 5 Sheet-Sheet 2 Filed April 20, 1955 TF1G Q INVENTOR: G'ashzv'asinlfi, BY 65A WATWRNEW Sept. 10, 1935. 5 GA$TR|H 2,013,883

LOOP FORMING MECHANISM FOR STRAIGHT KNITTING MACHINES Filed April 20, 1955 3 Sheets-Sheet 3 INVENTOR.

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Patented Sept. 10, 1935 LOOP FORMING IWECHANISM FOR STRAIGHT KNITTING MACHINES Gustav Gastrich, Wyomissing, Pa assignor to Textile Machine Works, Wyomissmg, Pa., a corporation of Pennsylvania Application April 2!), 1933, Serial No. 666,955

4 Claims.

This invention relates generally to needles for v straight or full fashioned knitting machines for selectively knitting plain and special loops, and

particularly to a spring beard knitting needle of novel form for cooperation with a loop engaging point member.

In the manufacture of run-resist or run-proof knitted fabrics and articles of wearing apparel, such as run-proof hosiery, plain loops are first formed and then selected loops, for example, alternate loops, are spread, by means of a row of coacting transfer or other loop engaging points, from the needles about which the loops are originally formed to other needles thereby to produce looking or barrier stitches for limiting or preventing runs in the fabric due to thread rupture. The loops may be spread from one needle to the next adjacent needle, or they may be spread across several needles, in the same course or in succeeding courses. When a loop is spread from one needle to another needle, a greater thread length than that in a plain loop is required, and since the loop prior to spreading is of ordinary length, the spread loops are under greater tension during the knitting operation than the plain loops, and this results in an increased flexure of the needles and a greater tendency for the loops to slip off the needles, or to be dropped by the transfer points, during the spreading operations The slipping of loops from the needles and transfer points results in the formation of loose chain stitches and holes, thus producing irregularities in the fabric, the loose chain stitches generally being caused by loops dropped from the transfer points during spreading, and the holes being formed by loops slipping from the needles during spreading, even though retained by the points,

Also, in the formation of spread loops heretofore, the various loops were initially positioned at substantially the same level by the knockover bits, sinkers and dividers, but no provision was made for maintaining the loops in such position, so that they positioned themselves in accordance with the varying tension applied to the different wales of the fabric, and were often caused to be spread about the beards of the needles; accordingly, loops of unequal length were formed throughout the fabric, thus resulting in fabric of uneven texture. Because of the increased tension on the yarn due to the greater thread length required for spread loops, a corresponding increased strain is exerted on the needles, so that the needles, and particularly the beards thereof, were subject to excessive bending and breakage when knitting run-proof fabric.

An object of my invention is to provide a needle, in which slipping of the loops from the needles during the spreading operation is a-prevented, 5 and which is adaptedto knit plain fabric, or runproof fabric, or a combination of the two, with equal facility. lnflthe 'f llustrat'ed herein, the needle is caused "t'o'f greater height than heretofore during'the-l op preading operation in order to insure thatthei'spreading of the loops takes place below the-b ards of? eedles; and instead of employing th ual 'ey .or groove for receiving the points, the "eedle jisia'provided with a point receiving groove which isjlonger than 5 that required for narrowing oriother loopf transfer operations for producing tran ferried or lajce form ing stitches, thereby to peniiit sliding movement. of substantial extent between the needle'and'the point while the point is engaged to the needle in the groove during the spreading operation,- so

that the needle may be elevated to a greater height than heretofore relative to the point,

. thereby causing the loop to be spread a substan-' tial distance below the beard and prevented by the beard from slipping off the needle. Sincethe loops are spread about the needles at a place closer to their point of support than heretofore, less strain is imposed upon the needles during the spreading operation, with consequent reduced bending and breakage of the needles.

Another object is to provide .means for positively positioning newly formed loops at a given place on the stems of the needles to cause the loops to be maintained at a predetermined uniform level during the loop spreading operation, which means will, however, permit the loops to slide under the beards of the needles at the proper time to enable the loops to be drawn through previously formed loops; in the specific embodiment illustrated, the stem of each needle has a recess or indentation therein which receives and positions the yarn during the spreading operation, and which releasesthe yarn upon a given movement of the needlesto permit the yarn to slide under the beards.

A further object is the provision of means for strengthening the needle at the point where the increased stress applied thereto during the spreading operation is liable to cause bending or breaking of the needles.

With these and other objects in view, which will become apparent from the following description of the illustrative embodiments of the invention shown in the accompanying drawings, the

invention resides in the novel elements, features of construction, and combination of parts in cooperative relationship, as hereinafter more particularly pointed out in the claims.

This application is a continuation in part of tion, of one form of a knitting needle and an as-' sociated loop engaging point, constructed in accordance with my invention;

Fig. 2 is a front view of the needle of Fig. 1;

Fig. 3 is an enlarged cross-sectional view taken along the line 3--3 in Fig. 2;

Fig. 4 is a diagrammatic view showing how the loop engaging points enter selected loops for performing the spreading operation;

Fig. 5 is a diagrammatic view illustrating an intermediate step inwspreading the loops to adjacent needles;

Fig.' 6 is a detail view taken substantially along line 6-6 of Fig. 5;

, '7 is a diagrammatic view showing'the loops spread over two adjacent needles;

-.'1 i gs'. 8 and "9 illustrate steps in a method of making the needle of Fig. 1;- Figs; 10 and 11 show, in various operating positions, at modified form of needle embodying the invention; and

Figs. 12 to 19 inclusive, illustrate the relative positions of certain elements when the points are I preading loops from one-needle to an adjacent needle.

' Referring particularly to Figs. 1 to 3, there is shown a spring-beard needle l3 and a loop engaging point l4 adapted to coact therewith for sp'reading or extending loops to or from the needle. The needle includes a butt-end crank portion l5 and a stem portion I 6 having a flattened portion l6a to provide increased clearance between adjacent needles, and for firmly securing the needle in the usual manner in the row of needles in a needle bar. The head of the needle has a spring beard l1 and-an eye l8 for receiving the tip I fact the beard in the usual manner.

Positioned adjacent to the eye I8 is a point receiving groove l8 separated from the eye by a wall portion or protuberance 20. The groove I9 extends from the protuberance towards the butt of the needle, and is of suflicient length to enable longitudinal sliding movement of such extent to take'place between the needle and point, after the end Ila of the point has-entered the groove,

as to make possible an increased elevation of the needles (in the direction indicated-by the arrow in Fig. 1) during this period to cause spreading to take place well below the beard, and to increase the time interval of engagement between the needle and point to facilitate the spreading operation. In a needle adapted for use in a full fashioned stocking machine of the type illustrated herein, the length'of the groove is (Figure 1) is preferably such as to provide for sliding movement between the point and needle of the order of eighty thousandths of an inch greater than the sliding movement required between a transfer point and its associated needle during narrowing or other loop transferring operations, thereby to permit an increased elevation of the needles to that extent, which increased elevation will IS an appreciable distance below the beards of the needles. In the type of needle heretofore used the sliding movement between the point and needle was of the order of seventy thousandths of an inch, whereas in the needle of Fig. 1 the 5 groove l9. permits sliding movement of the order of one hundred fifty thousandths of an inch, or approximately twice the movement formerly obtained. It will be understood, however, that the required length of the groove l9 may vary within relatively wide limits, dependent upon the particular type of knitting machine in which the needles are used.

Indentations or recesses 2| are formed in the walls 22 which define the eye l8 and groove J9, the recesses functioning to positively position a loop at a predetermined point on the stem l6 during the loop spreading operation to insure that the spreading takes place below the tip Ha of the beard, and also to cause the loops of the fabric to be maintained at a uniform level during spreading. The recesses have sloping sides adjacent to the protuberance 20, thereby facilitating the sliding of a yarn along the stem l6 into the transverse groove formed by the recesses, the rounded corners 5 of the recesses also aiding slipping of the yarn from the groove to facilitate entry of the yarn under the beard at the proper time in the knitting cycle.

The recesses 2| are preferably formed during 3() the pressing of the needle eye and with the same operation. The eye or groove of a needle is ordinarily pressed, by meansrof a power press and die, into the stem of the needle, in which operation the metal displaced from the groove by the die raises the sides of the groove above the original surface of the needle blank. Fig. 8 shows diagrammatically a power press in which a punch 22 is caused to engage a needle blank 23 lying in a die block 24, to produce the needle eye l8, the point receiving groove I 9, and the recesses 2| in one operation.

The punch 22 has two pressing edges 25 and 26 in alignment, and spaced from each other at the point 21, so that a section 20 of metal in the blank 23 is not acted upon by the punch. Since there is no metal displaced from the groove by the punch at the point 21, the surface of the blank of this point does not rise, but maintains its original level, to cause the depressions 2| to be 5 formed in the parallel sides of the groove. Although the recesses 2| are but slightly lower than the adjoining sides of the groove, nevertheless, these slight depressions are of sufiicient depth to positively position the loops therein during the 5.5 loop spreading operation; upon downward movement of the needle about which the loop is spread, however, the loop will readily slide out of the depressions and along the needle and under its heard in order that the loop may subsequentlybe drawn through the newly formed loops of the succeeding course. The section 20 of metal, re-

tained in the groove of the needle, strengthens the needle at the point where increased stress is applied thereto during the spreading operation. In Fig. 1 the point I4 also has indentations or recesses 29 formed in the walls of the groove 30, which recesses function to positively position loops on the point a predetermined distance from the end thereof and thereby prevent slipping of the loops from the point during the spreading operation. The recesses 29 are preferably formed in the point in the same manner as the recesses 2| in the walls of theneedle groove; the groove 20 cause spreading to take place around the stem of the point is ordinarily pressed, by means of a power press and punch, into the blank from which the point is formed, during which operation the metal displaced by the punch raises the sides of the groove above the original surface of the blank. By the use of a punch which has two pressing edges in alignment and spaced from each other, a section 3| of metal in the point 14 is not acted upon by the punch, and the surface of the point does not rise, but maintains its original level, thus causing the depressions 29 to be formed in the parallel sides of the groove which receives the spring beard I! of the needle. It is to be understood, however, that a point of the ordinary type, such as the point 33 shown in Figs. 4 to 7, may be employed with the needle l3, if desired, insteadof using the point of Fig. 1, the groove IQ of the needle permitting an increased elevation of the needle such that the loop on the point will be positioned a greater distance from the end of the point than heretofore, and thus prevent or minimize slipping of the loop therefrom.

In Figs. 4 to 7, I have shown in a more or less diagrammatic manner the relative change in position of the point 33 and needle l3 to produce an elongation of selected loops and-the spreading of the same into position to engage pairs of companion needles to enable the spread loops to interlock with plain loops in the fabric thereby to produce a run-proof fabric.

In Fig. 4, I have illustrated the points 33 as positioned while.descending into position to engage selected loops, preferably alternate loops 8, and in Fig. 5 I have illustrated the points as positioned while travelling from the needles to enlarge the selected loops, and to move the same into position over the associated plain loops 9, so that in the rising of the needles, as shown in Fig. 7, the latter will pass through the plain loops and the spread loops to receive a new thread and draw the same through the plain loops and spread loops to interengage a plain course In with the interlocking course ll. machine, the needles l3 are elevated to a higher position (eighty thousandths of an inch higher in the Reading machine) than that usually occupied by the needles in plain knitting, so that a better engagement may be obtained between the points and the selected loops and the time interval of operation between the needles and points varied to enable one limb of each selected loop to be caught under the beard of its'needle to prevent displacement of the loop when this particular needle passes by the knockover bits. In the knitting of plain fabric, it is not necessary for the needles I 3 to inove to this extra high elevation as the loops of the plain fabric are all cast off simultaneously.

It. will be seen from Fig. 6 that the ends of the loops 8 about the points 33 are somewhat higher, during the shifting or spreading movement of the points, than those parts of the loops in contact with the needles l3 from which they are spread, so that there is a tendency for the loops to slide upwardly on the stems of the needles and around the beards thereof. The loops are, however, momentarily held or positioned by the recesses 2| on the stems of the needles so as to cause the loops to be maintained below the tips of the beards ll during the spreading movement of the points, and thus prevent the spreading operation from taking place around the beards.

The recesses 2| also position the plain loops 9 at a predetermined level on the stems of the In the operation of the needles, and thus cause all of the fabric loops to be maintained at a uniform level during the spreading operation. The needles l3 are adapted to knit run-proof fabric, plain fabric, or a combination of the two, the recesses 2| causing the fabric loops to be positioned, at the proper times, at a uniform predetermined level, the recesses readily releasing the yarn upona given movement of the needles in either direction to permit the necessary sliding movement of the yarn along 10 the stems of the needles during the knitting cycle.

Figs. 10 and 11 are enlarged views of another form of needle 32 in accordance with the invention, as disclosed inmy copending application Ser. No. 623,206, above referred to, in which a single 15 groove 35 is employed, which groove not only receives the beard of the needle, but also extends buttwardly and permits travel of the point 33 down the needle a distance sufiicient to obtain a better engagement with the loop and a relative time operation between the needle and point to enable the spread loop to engage under the beard of its needle at the proper time in the knitting cycle. In Fig. 10 the needle and point are shown at-(a) with the point 33 in the groove 35 of the needle for the purpose of engaging the loop e positioned about the stem of the needle. In view (b) of Fig. 10 the needle has come up, and the point has travelled from c to d, which permits an increased elevation of the needle in its travel from c to :1 so that the needle rises approximately eighty thousandths of an inch higher when knitting run-proof fabric than when knitting plain fabric. In the usual type of needlethe distance from the tip or end of the beard to the lower end of the point receiving groove is approximately one hundred fortythousandths of an inch, and the transfer point enters the groove at a point midway between the end of the beard and the lower end of the groove, or seventy thousandths of an inch below the end of the beard, so that the maximum permissible travel of the point in the groove is approximately seventy thousandths of an inch; whereas in the needle of Figs. 10 and 11, the distance from d to f is approximately two hundred twenty thousandths of an inch, and the point has a permissible travel of approximately one hundred fifty thousandths of an inch, which is of the order of twice the permissible travel in the usual needle construction, and permits the above mentioned increase in elevation of the needles during the loop spreading operation.

Fig. 11 shows the point after the needle has moved away from engagement therewith, and illustrates how the loop e is positioned below the heard of the needle during the spreading operation. It will be seen that the loop is also positioned on the point at a substantial distance from the end thereof, and this prevents slipping of the loop from the point during spreading.

Referring to Figs. 12 'to 19 inclusive, I have illustrated in a more or less diagrammatic manner the relative movement of a single point I40 of the row of points and a single needle Ml of the row of needles for the spreading of a loop onto two adjacent needles. Figure 12 illustrates the point M0 in the beginning of its descent whereas Fig. 13 shows an intermediate position of the point and Fig. 14 shows engagement of the point with the heard of the needle. In Fig. 15,

I have shown the point pressing the beard of the needle and engaging the loop on the stem thereof, whereas in Fig. 16, I have shown the point moving from the needle to elongate the loop so as to be spread by a lateral movement of the point as shown in Fig. 1'7. In Fig. 18, I have shown the point again slightly moved downwardly to engage the beard of the adjacent needle with the spread loop positioned to allow said needle to pass upwardly through the spread loop. In this particular figure I have shown the loop engaging under the beard of the one needle, the adjacent needle that is to pass through the loop being positioned on the opposite side of this particular needle.

In Fig. 19, I have shown the point raised to its elevated position after the spreading of the loop around two adjacent needles. The needles are now in position to receive another thread to be drawn through the spread and plain loops of the interlocking course to form a, plain course. It will be noted in referring to Figs. 15 to 17 that when the loop is being elongated and spread the sinkers and dividers have been retracted to prevent interference thereof with the points in the lateral shifting thereof. It is, of course, to be understood that the cam surface of the pattern cam disc is such asto twice change the normal position of the shaft for a subsequent shift thereof to accommodate the alternate positions of the spread loops walewise of the fabric as clearly shown in Figs. 4 to 7.

The word spread as applied to loops throughout the specification is employed as meaning a loop that extends from the needle creating the loop to another needle in the row of needles, as distinguished from plain and transferred loops, which are bodily lifted from one needle and deposited upon an adjacent needle.

Of course, the improvements specifically shown and described can be changed and modified in various ways without departing from the invention herein disclosed and hereinafter claimed.

I claim: 5

1. As a new article of manufacture, a. spring beard knitting needle for a straight knitting machine, the needle having a groove in the stem thereof, and means in the walls of said groove for positioning, during certain knitting operations, a loop on the stem a predetermined distance below the tip of the beard.

2. As a new article of manufacture, a spring beard knitting needle for a straight knitting machine, the needle havingmeans comprising a recess in the stem thereof for positionin during certain knitting operations, a loop thereon a predetermined distance below the tip of the beard.

3. A die-pressed, knitting-machine implement comprising a shank portion of channel section having a riser in the channel constituting a reinforcing connection between the channel side walls and providing depressions .in the walls adjacent to the riser for positioning a yarn loop.

4. Knitting-machine needle and point elements for cooperation to spread a loop, each of which comprises a, die-pressed shank portion of channel section having a riser in the channel constituting a connection between tne channel walls reinforcing the implement against lateral strains incident to spreading the loop and providing space for metal displaced by depressions in the walls adjacent to the riser for positioning the loop.

GUSTAV GASTRICH.

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