Inventors:
Zwingenberger, Arno (Marxgrun, DT)
Hagel, Adolf (Bobengrum, Bavaria, DT)
Claims:
What is claimed is
1. A warp knitting machine comprising slide needles each having a straight trough-shaped shank with hooked head and a slide which includes an upper straight slide needle portion to close the hooked head in upper position and being at an angle to the remainder of said slide and displaceable longitudinally of the trough of the shank, means for executing swinging motions of both the shank and the slide about a common shaft, said straight needle portion not touching the bottom of said trough, and not radially emerging from said trough during operation of the knitting machine.
2. A warp knitting machine according to claim 1, wherein the trough has the shape of a with a flat bottom.
Description:
Warp knitting machines are known with slide needles having a straight, trough-shaped shank with hooked head and a beveled slide composed of straight parts, both executing swinging motions about a common axis.
This invention is directed to the problem of substantially improving the speed and smoothness of operation of such warp knitting machines. In addition, the manufacture of the slide needles, with no special precision requirements, is rendered economical and simple. According to the invention, this is achieved by so proportioning the upper beveled straight part of the slide that it attains the position required for picking up and casting off the loop, yet at the same time its bend remains in the trough of the shank, without interfering, in its lower open position, with the loop on the shank of the needle. The length of the upper beveled part of the slide and the working portion of the hooked needle are so proportioned and arranged that the two do not touch in the bottom of the shank trough. The construction and arrangement according to the invention makes it possible to employ slide needles having great flexural rigidity. A stable needle is obtained, not sensitive to lateral yarn tension and goods take-off stresses.
In the accompanying drawing:
FIG. 1 is a partial plan view with the knitting tools in section;
FIGS. 2 and 3 are fragmentary views on an enlarged scale showing the hooked head closed and open, respectively; and
FIG. 4 is a section through shank trough and upper beveled part.
The knitting tools consist of eyed needles 1, knitting bed 2 and slide needles 3. Each slide needle consists of a trough-shaped shank 4 with hooked head 5 and slide 6, consisting of an upper beveled part 7 and a straight shank portion 8. The trough-shaped shank 4 and straight shank portion 8 of the needle are secured to beds 9 and 10 by means of cover plates 11 and 12, fastened in position by means of screws 13 and 14 as shown in FIG. 1.
The two beds 9 and 10 are supported by swing levers 17, 18 and moved about the swing shaft 21 by plungers 19, 20 with intermediate angle brackets 15, 16. On the swing shaft 21, the two swing levers 17, 18 may be mounted on ball bearings 22.
The needle shank 4 has a trough 23 in which the upper beveled straight portion 7 of the slide 6 travels. The arrangement and proportions of shank and slide and their motions are such that the upper beveled straight portion 7 of slide 6, when the position required for picking up and casting off the loop is reached, has its bend 24 still within the trough 23, without interfering, in the lower open position of FIG. 3, with the loop 25 on the shank of the needle.
In FIGS. 2 and 3, wherein the knitting tools are shown on an enlarged scale, FIG. 2 shows the upper slide position, in which the hooked head 5 of the shank is closed by the upper straight portion 7 of the slide. FIG. 3 shows the lower slide position, in which the hooked head is open. The upper beveled straight portion 7 of the slide is arranged as a tangent to the radius R (FIG. 1) so that in swinging relative to the shank 4, or head 5, of the needle, it remains in the track of radius R, neither emerging from the trough 23 nor touching the bottom 26 of the trough of the shank 4. This results in the important advantage that friction of the slide in the trough is eliminated, which prevents heating and frictional wear of the slide needle.
A special advantage, above all, is to be seen in the fact that the upper straight portion 7 of the slide can be kept as short as possible, i.e., just long enough that in the upper closed position of FIG. 2, its point closes the hooked head 5, while the bend 24 just continues to be guided in the trough 23 of the needle. This shortness of the upper bevel portion 7 of the slide makes it possible to produce the needle shank and slide as straight parts, although the two parts move radially to each other. This results in especially simple and economical manufacture, with no high precision requirements. This stable and flexurally rigid construction of the slide makes it possible for the slide to move freely without tension, i.e., without contact pressure, in the bottom 26 of the needle trough (FIG. 4).