US2434782A - Power-operated flat frame knitting machine - Google Patents

Description

19478- c. D. ALEXANDER El AL 2,434,732

POWER-OPERATED FLAT FRAME KNITTING MACHINE Filed Feb. 14, 1946 Fatented Jan. 20, 1948 POWER-OPERATED FLAT FRAME KNITTING MACHINE Cecil Drummond Alexander and .Samuel Gibson, Irvine, Scotland, assignors to British Textile Manufacturing Company Limited, Irvine, Ayrshire, Scotland, a corporation of Great Britain Application February 14, 1946, Serial Non-641,490

Great Britain December 3,1945! 3 Claims. (Cl. .66-147') This invention relates to apparatus for tensioning fabric being knitted in a power-operated fiat frame knitting machine and contemplates the provision of simple and readily applied tensioning means for restraining fabric being knitted against contraction as the knitted fabric is being fed from the needle bed to the take-down roller.

In fiat frame knitting machines as heretofore constructed when knitting a piece of fabric with two selvage edges there is an immediate tendency for the fabric to contract and for the outer selvage edge of the piece to be pulled down by the take-down roller in an irregular manner, result.- ting in dropped stitches andan irregular ed e at the welt or separating course.

The p s n n er l iqrl o i es the d w a s by providing adjustable fingers at opposite sides of the machine, each finger being adapted to pass through the loops of the respective selvage stitches, whereby the fabric is held in such position that the respective outer selvage edge is knitted with the same length of stitch as at the centre of the fabric, resulting ina level pull-down of the fabricand the formation of a straight edge at the welt or separating course, .and ensuring that the fabric is maintained at the full width of the needle field, without contraction, until the piece has passed through :the take-down mechanism.

Further, the-risk of dropped stitches, generally due to irregularity of take-down, is eliminated, as the tension fingers engaging the selvage loops of the fabric permit more accurate control of the take-down tension.

In a practical embodiment of the invention there are provided on the chassis at opposite sides of the machine and outside the knitting width of the needle beds two bracketseach having in its head a horizontal passage preferably co-planar with the centre line of the space between the needle beds, or in the case of a single needle bed, in acorresponding position relatively to said needle bed.

Slidably and adjustably mounted in each bracket is a tension member comprising a hori- .zontalrod formed or furnished at one end with a depending finger. The tensionfingers are adapted to pass downwards through loops of selvage stitches to be closely adjacent to the periphery of the take-down roller.

In the working of the machine one yarn guide passes to one side of each tension finger to form a selvage stitch after passing the finger While a 12 o the other side of the finger t form asuc ee ns sal a stitch- The tension fingers hold the selvage edges of the fabric parallel to ,the centre line of the fabric being knit, resulting in a level pull down of the knit fabric by the take-down roller, thereby ensuring the same length of stitch at the selvages as at the centre of the fabric and a straight edge at the welt or separating course.

The tension fingers are adjustable towards and away from the centre of rows of the needles in accordance with the width of the fabric to be knit.

The fingers are necessarily slender to be able to ass downwards between the needlebeds. The resistance of the depending fingers to the pull of the fabric is strengthened by the close proximity of the tension members to the needles forming the salvage stitches. To afford still further resistance itis advantageous to form each finger of a flat bar section with the narrow edges rounded and presented in the plane of the centre line bes ond sn de as es tween the needle beds. Or the fingers may be of any other desired shape in cross-section, desi n d to give the greatest resistance, and may be of tubular or solid construction.

Where two or more pieces of fabric are 'being knit simultaneously in a machine, it will be obvious that a depending finger will be necessary for each selvage edgef Additional slidable and adjustable tension members mounted in additional brackets each comprise a horizontal rod which is continued at right angles, so that the end of the rod furnished with the depending finger will "be at right angles 'to the direction in which the horizontalrod slides in the respective bracket.

The application to a fiat frame knitting machine of a-tension device as described is advan- ,tageous in that the space betweenthe selvages of the fabric above and along the length of the machine is free from obstruction and thereby facilitates manipulative action of the operatorin dealing with needle breakages and changes, knitting faults, partial or complete presses-off andthe'lifti ng of the fabric on tothe needles.

Usually only one piece of fabric having a selvageialong each edge is knit atone time-ina machine. 'Wherea machineis adapted :to knit two or more pieces of fabric simultaneously with selvages intermediate the outer edge selvages; it will be necessary to provide additional tension fingers to engage said selvages.

The tension device for location intermediately of the two outer tension devices may be carried a by a bracket secured to the frame of the machine or preferably to the usual table at the rear of the machine.

In this construction the horizontal portio of each intermediate tension member is angularly bent to project over the adjacent needle bed and then downwards to provide a tension finger for passage between the two needle beds and into the said intermediate selvage.

Some exemplificatory embodiments of the invention will now be described with reference to the accompanying drawings in which only so much of a fiat bed knitting machine is shown as is necessary for a clear understanding of the invention.

In the drawings Fig. 1 is a side view and Fig. 2 an end view of a tension device according to the invention, shown separate from the knitting machine; Fig. 3 is a sectional view, drawn to a larger scale, through the line IIIIII of Fig. 1; Fig. 4 is a fragmentary transverse sectional view, drawn to a larger scale, of a knitting machine, showing in position the tension device illustrated in Fig. 1; Fig, 5 is a fragmentary plan view of front and back needle beds of a knitting machine with a tension device in position thereon and illustrating how the yarn guides travel in relation to the tension fingers to form the selvage stitches; Fig. 6 is an end view and Fig. '7 a plan of a modification.

Referring to Figs. 1 and 2 which show one of the tension devices separate from the knitting machine, I0 is a bracket having a foot H and a head [2 with a horizontal passage l3 therethrough in which is slidably mounted a rod i i secured in a position of adjustment in the head 12 by screws I5. The rod I4 is formed at one end with a depending finger l6 perpendicular to the rod Hi. The finger I6 is required to be of slender construction and in order to afford the requisite strength the finger I6 is formed to a flattened section with rounded edges, as shown in Fig. 3.

Although it is to be understood that in a practical embodiment of the invention there are provided at opposite sides of the knitting machine two similar tension devices, for convenience in description and illustration only one of said tension devices will be described and illustrated.

Referring to Figs. 4 and 5, the bracket IE is secured to a plate I! secured to and bridging the carriage rails l8, IQ of the machine and also secured to the frame of said machine, outside the limit of width of the needle beds 21, 22. The disposition of the bracket H3 in relation to the needle beds 2|, 22 is such that the horizontal passage l3 in the head 12 is in the vertical plane of the centre line of the space between the adjacent inner ends of the needle beds 2|, 22. The depending finger [6 of the tension device extends downwards, between the needle beds 2|, 22 to a point in close proximity to the periphery of the takedown roller, indicated at 23, Fig. 4, and through the loops of the selvage stitches.

In the working of the machine one of the usual yarn guides indicated at 24, Fig. 5, passes to one side of the tension finger Hi to form a selvage stitch after passing'said finger, while a second yarn guide, indicated at 25, passes to the other side of the finger Hi to form a succeeding selvage stitch.

The intermediate tension fingers may be carried from the usual yarn table at the rear of the machine, as shown in Figs. 6 and 7, in which parts corresponding to those shown in Figs, 1 to 3 are indicated by the same reference numerals distinguished by the addition of the letter 0.

In this construction the bracket 10 is carried on the yarn table, indicated in dotted lines at 31, Fig. 6, located at the rear of the machine. The horizontal member l4 is angularly bent at W to extend over the adjacent needle bed and is formed or provided at the outer end of the part [4' with a tension finger Hi Alternatively, the bracket may be carried on a rail secured to the machine frame.

What is claimed is:

In an apparatus for tensioning fabric bein knitted in a flat frame knitting machine, the combination with at least one needle bed, needles and yarn guides cooperating in forming selvage loops at the edges of the fabric being knitted, and a take-down roller, of a unitary tension member at each side of the machine having a finger positioned to extend downwardly through the loops of selvage stitches, said finger extending to a point closely adjacent to the periphery of the take-down roller, whereby to prevent any loop distortion and to maintain the original stitch formation along the full width of the knitted fabric continuously to the nip of the take-down roller.

2. In an apparatus for tensioning fabric being knitted in a fiat frame knitting machine of the type in which at least one needle-bed, needles and yarn guides cooperate to form selvage loops and a take-down roller for the fabric is mounted beneath the needle bed, the improvement which comprises a rigid slender depending tension member positioned to extend downwards parallel to the center line of the fabric through loops of selvage stitches of the fabric being knit to a point closely adjacent to the peripher of the take-down roller, whereby a selvage edge of the fabric is held parallel to the center line of the fabric being knit to a point approximating its engagement with the take-down roller.

3. An apparatus as defined by claim 2 in which the tension member is a flat bar having a narrow rounded edge and being positioned in a central vertical plane coincident with the normal position of the fabric extending from the needle bed to the take-down roller.

I CECIL DRUMMOND ALEXANDER.

SAMUEL GIBSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 876,815 Lippitt Jan. 14, 1908 2,067,841 Heinitz Jan. 12, 1937 FOREIGN PATENTS Number Country Date 116,098 Germany Jan. 9, 1901 487,312 Great Britain Junel'l, 1938

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