US2892331A - Knitting machine for producing cut pile fabric - Google Patents

Description

w; J. KELLY 2,892,331

.KNITTING MACHINE FOR PRODUCING CUT FILE FABRIC June 30, 1959 Filed April 23, 195'? m wE United States Patent KNITTING MACHINE FOR PRODUCING CUT PILE FABRIC Walter J. Kelly, Amsterdam, N.Y., assignor to Mohasco Industries, Inc., Amsterdam, N.Y., a corporation of New York 7 Application April 23, 1957, Serial No. 654,526

. 1 Claim. (Cl. 66-85) This invention relates to knitting machines of the warp type, which are provided with means for engaging weft yarns and holding them to form pile loops on the face of the fabric as the knitting proceeds. More particularly, the invention is concerned with improved means for use on a warp knitting machine, which holds weft yarns laid successively thereon to form pile loops and operates, after a plurality of loops have been so formed, to sever the loops one at a time and thus convert each loop mto a pair of pile tuft legs. The loop-severing means of the invention may be employed in knitting machines in WhlCh the needles reciprocate in either a vertical or a horizontal plane, but, for purposes of explanation, the application of the invention to a machine having vertical needles will be illustrated and described in detail.

For better understanding of the invention, reference may be made to the accompanying drawing in which Fig. 1 is a vertical cross-sectional view through part of a knitting machine provided with the new loop-cutting means;

Fig. 2 is a fragmentary plan view showing parts of the machine and cutting mechanism; and

Fig. 3 is a fragmentary elevational view showing the action of the shear blades.

The loop-cutting means of the invention is illustrated in Fig. 1 in association with a knitting machine of conventional construction, which comprises a vertical trick plate having a head 11 with spaced vertical slots for the needles 12. The needles shown are of the ordinary latch type and they are mounted in the usual way in leads 13 carried by a bar, which is reciprocable to move the needles up and down during the knitting operation. The machine is provided with a plurality of sets of yarn guides 14, 15, 16 and the guides of each set are carried by bars, such as the bar 17. The several bars are mounted for swinging movement transverse to the row of needles and are also capable of being shogged endwise in the usual way. The guides 14 handle the warp yarns W, of which the chain stitches are made, while the guides 15 are for the pile weft yarns P, and guides 16 for the back weft yarns B. When the bars are swung, the lower ends of the guides describe circles below the level of the tops of the needles when the latter are in their top position.

In order to form loops of the pile tuft yarns, the machine is provided with a set of stationary plush points 18, which are mounted on a bar 19 and lie in the planes of respective needles. Each plush point has a horizontal or base portion 18a and an inclined vertical portion 18b and the portions 18b of the plush points are spaced from the trick plate by a distance, which depends upon the length of the loops to be formed. The bar 19 carrying the points is mounted on the knitting machine in any convenient manner, and, in the construction illustrated, the bar is secured to the vertical flange of an angle iron 20 carried by the machine frame.

The horizontal flange of the angle iron 20 carries a number of bearing blocks 21 for a rock shaft 22 formed with spaced flat surfaces, to which the lower end of arms 23 are bolted. The arms are secured near their upper ends to thevertical flange of an angle iron 24, the horizontal flange of which supports a bar 25, on which a plurality of cutting blades 26 are mounted. There is one blade 26 for each of the plush points 18 and the forward cutting edge 26a of each blade 26 slopes upward and away from the plush point at an angle. The blades 26 are so positioned as to bear against the sides of the horizontal portions 18a of their respective plush points and the cutting edge of each blade projects above the top of the horizontal portion of its related plush point, as shown in Figs. 1 and 3.

At its upper end, each arm.23 carries a pivot pin 27, on which is mounted one end of a link 28 having its other end connected pivotally to a lever 29 pivoted on a part of the machine frame. The lever has a roller 30 hearing against the surface of a cam 31 on a shaft 32 supported for rotation on the machine frame, and a spring 33 connected at one end to an ear 29a on the lever and at the other to a bracket 34 on an angle iron 35 attached to the machine frame, tends to swing the lever clockwise and maintain roller 30 against the surface of the cam.

In the operation of the knitting machine, the needles reciprocate vertically in the usual way and the yarn guides 14, 15, 16 are swung and shogged relatively to the needles. In these operations, the warp yarn guides 14 lay the warp yarns W around the individual needles so that, when the needles descend, chain stitches will be formed. Each of the guides 16 is swung across two or more needles and lays its yarn B against the back of the needles, so that the back weft yarns are caught in the chain stitches and serve to connect the stitches together and form a fabric. The guides 15 for the pile yarns P are shogged, when the guides lie at the back of the plush points and remote from the needles, and each guide 15 is shogged past one needle only, so that, on the return swing of the guide, its yarn will be wrapped about the plush point associated with the needle. As the result of this action of the guides 15, a succession of loops of pile yarn is laid on each of the individual plush points 18.

In each cycle of the knitting machine, cam 31 makes one revolution and acts through lever 29 and link 28 to cause the bar 25 to move the cutting blades 26 toward the plush points and back. As the loops of pile yarn (are formed successively on the plush points, the loops travel down the respective points in succeeding knitting cycles, until the leading loop of each series on a plush point lies in the angle between the horizontal portion 18a and the vertical portion 18b of the point. When the loop arrives at this place, the blade 26 associated with the plush polnt moves forward and severs the loop. In its movement, the blade engages the side of its associated plush point and cuts the loop with a shearing action, in which the edge of the plush point along the sides of the angle between its vertical and horizontal portions cooperates wlth the cutting edge at the forward end of the blade, as shown in Fig. 3. At the time of the cutting operation, two other loops of yarn lie above the lowermost one, but the inclination of the cutting edge 26a of each blade and the length of its stroke are such that, when the blade makes a cutting stroke, it severs only the lowermost loop. The two loops left on the point move down a step in the next cycle so that, when the blades again move forward, another loop is in position to be cut. By thus retaining a number of loops on each plush point and cutting only the lowermost loop, the uncut loops are held taut so that their ends can be properly anchored in the stitches of the fabric with the loops at full length.

As the knitting operation continues, the knitted fabric travels down the vertical face of the trick plate with the tuft legs T formed by the cutting of the loops passing between the blade end and the vertical flange of the angle iron 20. 'Thefabric is taken up in the usual way and is ultimately finished by the shearing of the upper ends of the legs of the cut loops to form a pile of uniform height.

I claim:

"In a warpknitting machine"having a row of reciprocable needles,1a' set ofguidesoperating to lay warp yarns about the'needles' to enable the needles to knitchains of stitches 'of theyarns,and sets of guides'movable transverselyand lengthwise of the row'of" needles to lay back weft yarns and pile weft yarns, respectively, in the stitches of the chains, thecombination of a plurality of stationary plushpoints lying parallel to and in the planes of respective needles and extending from'one side of the paths of travel of the pile yarn guides'to. the other in position to hold a seriesof pile yarn loops laid successively thereon by said guides, each plush point havinga loop-receiving portion-lying substantially'parallel'to the needles and a baseportion "lying at an angle'toithe loop-receiving portion and extending away from the row of needles, blades movable along and in contact with respective points, each blade having a cutting edge =at its forward end extending obliquely relative to the direction of movement of the blade and the cutting edge of each blade being adapted to co-operate with the edgeof its associated plush point between the loop-receiving and base portions of the plush point to sever the inmost loop of pile yarn von the loopreceiving portion of the plush point with a shearing action, and means for moving said blades relative to their associated points to sever pile yarn loops on the points.

References Cited in the file of this patent UNITED STATES PATENTS

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