US 1947302 A
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Feb. 13, 1934. MElWALD 1,947,302
CORD SHAPED KNITTING COVERED BODIES AND METHOD OF MAKING SAME Filed Sept. 3, 1931 Patented Feb. 13, 1934 UNITED STATES CORD-SHAPED KNITTING-COVERED BODIES AND METHOD OF MAKING SAME Franz Meiwald, Vienna, Austria Application September 3, 1931, Serial No. 561,066, and in Germany August 11, 1931 Russuw 2 Claims. (01. 66--190) I have filed applications as follows: Germany, August 11, 1931; Czechoslovakia, August 18, 1931; Hungary, August 13, 1931; the Netherlands, August 14, 1931.
I This invention relates to strand elements with a knitted tubular covering, and more particularly to knitting-covered electric conductors and cables and similar elongated elements. It has already been proposed to provide such bodies, and in particular electric conductors and cables, with a knitted instead of a braided or plaited covering for the protection of the insulation or as insulation, since in this way a considerable saving of material and labour can be eiiected, in consequence of the very much greater working capacity of the knitting machine as compared with the rapid braiding machine. The saving thus effected is the greater the longer is the knitting machine used, and there is thus an incentive to 90 increase as far as possible the length of the loops of the knitted covering. This tendency is, however, accompanied by a certain disadvantage in the appearance of the knitting-covered body, since the rows of knots spaced the length of the loops apart become very prominent, and that more particularly when, for particular reasons. the longitudinal lines of the stitching run spirally, for which reason the rows of knots become too prominent to make a smooth appearing surface.
30 Coverings of this type are disclosed for instance in my United States Letters Patents numbered 1,814,324 and 1,936,519 which show central strand elements enclosed by a knitted covering which, however, has the above mentioned objections.
The present invention has for' its object to obviate this drawback without increased consumption of thread material and working time, and consists essentially in effecting the longitudinal displacement, i. e. staggering.', of the neigh- 40 bouring stitches or loops in relation to each other. The result obtained is particularly effective when this displacement is achieved by spacing of the loops in a row and displacing alternate rows longitudinally of the cable or cord being covered, so
that the loops of each successive row overlie the fioat between adjacent loops of the preceding row.
Such methods of knitting are known per se but have not been employed hitherto in knitting a covering on to cord shaped bodies, in which they constitute a new use, by which novel effects and results are produced which are of great advantage in circum-knitted strand elements referred to hereinbefore.
In the accompanying drawing, like characters of reference indicate like parts in the several views, and
Figure 1 is a diagrammatic view of one form 01. knit covering in accordance with this invention. 1
Figure 2 is a schematic view'oi a part of a knitting machine as used to knit the form shown in Figure 1.
Figure 3 is a view similar to Figure 1 but showing a modified form of knitting.
Figure 4 is a view similarto Figure 2 but showing the arrangement for knitting the modified form. q
The invention is illustrated in the accompanying drawing by diagrammatic representations of the stitching method, and by diagrammatic representations of two examples of the cam cylinder of the knitting machine in accordance with the invention, showing the needle guiding. In the knitting method shown in Fig. 1 the wales of circumferential consecutive loops are somewhat displaced longitudinally in relation to each other by a circumferential alternative succession of shorter and longer loops, so that the wales described circumferentially a zigzag line, and are thereby rendered less prominent in the finished covering. For the manufacturing of this type oi knitted covering the cam cylinder 1 shown developed in a plane in Fig. 2, with needles 2, 3 of different length, are employed. The shape of the cam cylinder implies that each needle works twice at each revolution. Long and short needles are arranged alternately in a row, thus effecting the displacement of the loops in relation to each other.
As illustrated in Figure 2, two needles are shown in the needle cylinder, both. of which are operated to move upwardly and downwardly by a single cam curve. In other words, the lower ends of the needles both engage in the same cam groove. The form of the curve is diagrammatically illustrated in Figure 2.
In the knitting method illustrated in Fig. 3, adjacent loops of a circumferential row are double spaced, but not staggered in the row as in Fig. 1. The loops of the next consecutive row which is knitted with a diiferent thread are, however, circumferentially displaced with respect to the position of the loops in the preceding row, so that they overlie the float between adjacent loops of the preceding row, thus again producing the eifect sought by the invention. In this manner, the loops of a next consecutive row also cover, and bind against the core, the circumferentiall'y extending thread. nes le: .vnich eonalso be employed for obtaining the displacement nect adjacent loops of preceding row. ihis of the stitches in accordance with. the present is extremely important in covering a core by a knitted fabric, because as far as I am aware this is the first successful attempt to cover a core, for instance a cable or wire, with knitted fabric which can not be unraveled. The reason for this is that by the manner in which this fabric is knitted, namely, with a plurality of independent threads, several independent knitted fabrics are knitted into and between another, so that threads of one i'a'oric bind the threads 0; the other fabric. The cam cylinder 4 (Fig. i) employed for the manufacture of this type oi covering has two grooves 5, 6, each of which has two high points. The individual high points are displaced 90 to each other. Counting the needles consecutively and beginning with one or those guided by the upper groove all odd numbered n edles are guided by this upper groove while all even numbered needles are guided by the lower groove. The knitting is done over a suitable core or body 7 around which the stitch line or i s run spirally. The alternate heads or upper ends 9 and 10 of the knitting loops are ar ranged on a staggered line 11 which extends spirally around the core *2.
The described forms of construction can be combine iurther Emitting methods can invention.
1. The combination with a central strand element of a "Knitted fabric surrounding said element and being composed of a plurality of threads formed into a plurality of individual spiral rows of circinnferentially spaced loops with floats b ween the adjacent loops, the loops of each successive row extending part into the spaces between the adjacent loops of the next adjacent row and overlying the floats between said adjacent loops whereby the loops of ad. jacent rows form a circumferential zigzag iine around the element.
2. The method of covering strand elements consistine' in knitting around said strand elea of individual spiral rows of loops 115,. L relatively l'ng floats between the adjacent loops, and :ning the loops of each successive row part way into the spaces between the adjment loops oi? the next adjacent row in position to overlie the floats between the adjacent loops whereby the loops of the adjacent rows form a circumferential zigzag line around the element.
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