Feed System Of A Resiliently Elongated Yarn In A Hosiery Machine And Especially In A Stocking Machine

Abstract

A yarn guide provided with a rocking lever for the feeding of yarn, in stretched condition, to circular knitting machines, the guide and the lever having opposed surfaces which permit free passage of the yarn therebetween when the yarn is being fed to the machine and which press upon and clamp the yarn therebetween when feeding of the yarn is discontinued.

Description

BACKGROUND

It is known that the use of "stretch" yarns is increasing generally in the art of knitting and particularly so in the field of ladies' circularly knit hosiery. This yarn is fed under tension sufficient to insure that the yarn is knit in its stretched condition so that the resulting knitted article, such as hosiery, will properly fit the wearer thereof. Conventionally, a tensioning device is used to apply the desired tension to the yarn and said device is usually positioned at a relatively great distance from the needle circle. When the yarn is cut and no longer tensioned, it tends to contract to resume its relaxed condition and, therefore, its free end will tend to move in the direction opposite to the direction in which the yarn was fed. When conventional non-stretch yarns are cut, there is no difficulty in securing the ends thereof in conventional clamping and cutting devices, however, due to the reverse movement of the stretch yarns when knitting thereof is discontinued, there is difficulty in securing the cut ends thereof in the conventional clamping and cutting devices.

THE INVENTION

It is the principal object of the invention to provide means to control the stretch yarns adjacent the needle circle when the feeding thereof is discontinued, so that the yarn ends will be properly secured in the conventional cutting and clamping devices of circular knitting machines, that is to say, the cut ends of the yarns will not be pulled out of the conventional clamp due to the tendency of the yarns to contract.

It is also an object of the invention to provide a yarn guide for the feeding of stretch yarn (in stretched condition) to the needles of a circular knitting machine, which will permit the yarn to move freely in one direction through the guide when the yarn is being fed to the machine and which will prevent passage of the yarn in the opposite direction through the guide when feeding of the yarn is discontinued.

It is an object of the invention to provide a yarn guide with a rocking lever adjacent its yarn feeding end with the guide and the lever having opposing surfaces which permit substantially free passage of the stretch yarn therebetween when the yarn is being fed to the machine and which press upon and clamp the yarn therebetween when feeding of the yarn is discontinued. The lever is biased by a weight or by a spring to move its yarn engaging surface toward the yarn engaging surface of the guide, and is also urged toward the surface of the guide by the tensioned yarn itself when the latter is to be cut and clamped.

IN THE DRAWING

FIG. 1 is a side view of a yarn guide embodying the present invention, the yarn guide being shown in association with the elements of a circular knitting machine with which it co-operates;

FIG. 2 is an enlarged detail view, partly in section, of the yarn feeding end of the yarn guide; and

FIG. 3 is a sectional view of FIG. 2 taken on lines III thereof.

According to what is illustrated in the accompanying drawing, 1 denotes the needles sliding in the longitudinal grooves 3A of a cylinder 3, which includes an outer rim 5A, with radial grooves for the sinkers 5 designed to co-operate with the needles. 9 denotes a plate which co-acts with the cap of the dial 15 to define a suction passage 11. This passage is similar to passage 10 of Dusik U.S. Pat. No. 3,224,230 in that it serves to retain the cut ends of the idled yarns in the general manner set forth in said patent; 13 denotes the transfer hooks which are accommodated in radial grooves of dial 15.

One or more yarn-guides are arranged on the fixed structure surrounding the needle cylinder, one at each feed, and are movable into, and out of, yarn feeding positions in the well known manner. In general, the yarn-guides may be pivoted on supporting pin 17 and are operated by a tripping cam drum 19, also in a well-known manner.

According to the invention, the yarn-guide shown in the drawing and indicated by 21, (which, like all the other guides is assembled on the pin 17 and is operable by the cams, (drum 19), acting on its extension 21A), has at its active end 21B, (which is adjacent the needle circle), a downward extension which has a surface 21C. Adjacent the upper and lower ends of 21B are guide eyelets 23A and 23B for the yarn 25; in this way, the yarn is guided to slide along the surface 21C, which is slanted upwardly and away from the needles cylinder axis. Adjacent the end 21B of the yarn guide 21, by means of ears 21E and pin 27, there is oscillatorily mounted a lever member 29 which has, at the end next to the needles circle and in front of the surface 21C, a head 29A shaped with a profile directed towards the arriving yarn which slides thereover in the direction of the arrow f1. At the opposite end of lever 29 and thus on the opposite side to the head 29A with respect to the pin 27, the lever 29 has a weight portion 29B; this weight tends to turn the oscillatory lever 29 in a counterclockwise direction, and thus in such a direction as to lay the head 29A against the surface 21C, keeping a certain inclination between the perpendicular to the surface 21C and the line defined between the contact zone of the lever with the surface 21C and the oscillation axis of the lever; the angle must be smaller or equal to the angle of friction between the lever and the yarn.

The arrangement is such whereby, when the yarn 25 from the cone 31 is stretched as it passes through a conventional tensioning device T and is pulled by the needles in the direction of the arrow f1, it may easily slide between the head 29A and the surface 21C, being guided by the eyelets 23A, 23B, with the pressure exerted by the weight 29B being very small. After the feeding of the yarn 25 is discontinued and the yarn is sheared, it is no longer pulled by the needles and tends to be shortened and thus to slide in the eyelets 23A and 23B in a direction opposite the arrow f1; this is prevented by the effect of the head 29A which is urged against yarn 25 to clamp it against surface 21C, the head 29A being so urged by the weight 29B and by the action of the yarn 25 as it tends to contract.

In this way, it is possible to maintain tension on the yarn between the cone 31 and the yarn guide 21. Also, after the stretch yarn 25 is cut and in the absence of a clamp upon the cover 9; the yarn between its severed end (which is generally sufficiently spaced from the yarn-guide) and the head 21B of the raised yarn-guide, although being shortened, may be kept within the range of the intake end of the pneumatic suction passage 11 or the like, and thus may be retained in a position to be taken by the needles, when the yarn-guide 21 is lowered again to return the yarn 25 into operation.

The drawing illustrates an embodiment of the invention, which may be varied in the form and arrangement. For instance, one may provide for an arrangement similar to the weight 29B on the lever 29 with the aid of a resilient means, or shaping the lever like a fixed spring, instead of being oscillatory with respect to the yarn-guide 21. However, it seems that the weight solution is the simplest and most sensitive, besides exerting more stable pressure upon the yarn.

It will be seen from the foregoing that the invention resides in providing a conventional yarn guide, or finger, 21, with abutment surface 21C; in pivoting lever 29 to the yarn guide; in providing a weight 29B to bias the lever in counterclockwise direction, and in passing the yarn between the end of the lever and the abutment surface, the friction of the yarn moving between the end of the lever and the abutment plate being substantially equal to the action of the weight, so that the lever is inactive. But, when the yarn is no longer being knit, it tends to contract by moving in a direction opposite to the direction of the arrow f1. The friction of the yarn moving upward, as viewed in FIG. 2, added to the action of the weight, rotates the lever in counter-clockwise direction to clamp the yarn between head 29A and surface 21C. Since the structure responsible for this result is fully shown in FIG. 2, it is thought that a detailed disclosure of the knitting machine is unnecessary.

Claims

What I claim is:

1. In combination with a circular knitting machine of the type having a circle of needles, a yarn guide adapted to be selectively moved into and out of yarn feeding positions relative to the needle circle to feed stretch yarn to the needles to be knit thereby, means for tensioning the yarn whereby it is in stretch condition between said tension means and said needles, yarn holding and cutting means for holding and cutting said yarn upon discontinuance of the feeding thereof to said needles, said yarn guide having an active end including an abutment surface along which the yarn passes and the yarn guide being disposed adjacent said needle circle when said guide is in yarn feeding position, a clamping member attached to said yarn guide and including a free end portion terminating in a head, means normally urging the head of said clamping member toward said abutment surface of the yarn guide under a predetermined pressure, the yarn associated with said yarn guide and passing along said abutment surface being disposed between the head of the clamping member and said abutment surface of the yarn guide, said last named means being responsive to movement of said yarn across said surface in the feed direction under knitting tension to move said head away from said abutment surface, and said last named means being responsive to movement of said yarn across said surface in the opposite direction after the yarn is cut and feed is discontinued to move said head toward said abutment surface, whereby the yarn is allowed to move through the yarn guide under knitting tension in the feed direction, but is clamped between the head of the clamping member and the abutment surface of the yarn guide when the yarn is cut and feed is discontinued, thereby preventing the yarn from moving in the opposite direction.

2. In combination with a circular knitting machine of the type having a circle of needles, a yarn guide adapted to be selectively moved into and out of yarn feeding positions relative to the needle circle to feed yarn to the needles to be knit thereby, said yarn guide having an active end including an abutment surface across which the yarn is fed to said needle cylinder, a clamping member attached to said yarn guide and including a free end portion terminating in a head, means normally urging the head of said clamping member toward said abutment surface of the yarn guide under a predetermined pressure, the yarn associated with said yarn guide and passing across said abutment surface being disposed between the head of the clamping member and said abutment surface of the yarn guide, said last named means being responsive to movement of said yarn across said surface in the feed direction under knitting tension to move said head away from said abutment surface, and said last named means being responsive to movement of said yarn across said surface in the opposite direction after the yarn feed is discontinued to move said head toward said abutment surface, whereby the yarn is allowed to move through the yarn guide under knitting tension in the feed direction, but is clamped between the head of the clamping member and the abutment surface of the yarn guide when the yarn feed is discontinued, thereby preventing the yarn from moving in the opposite direction.

3. A structure according to claim 2 wherein said clamping member comprises a lever with first and second end portions, said first end portion terminating in said head and said second end portion being of greater weight than said first end portion, and means pivotally connecting the lever between its end portions to the yarn guide with the head adjacent said abutment surface of the yarn guide.

4. A structure according to claim 3 wherein guide eyelets are provided at opposite sides of the abutment surface of the yarn guide for directing the yarn between the head of the clamping member and the abutment surface.

5. A structure according to claim 4 wherein said yarn guide includes a vertical component joined to a horizontal component and wherein said abutment surface extends along said vertical component and said eyelets are spaced inwardly of said vertical component and in substantial alignment with the abutment surface, a pair of ears depending from the horizontal component, said lever being pivotally supported between said ears with its weighted second end depending downwardly and normally urging the head of the lever upwardly toward the abutment surface and against the yarn extending through the guide eyelets.