US 2968085 A
Description (OCR text may contain errors)
Jan. 1 7, 1961 R. R. MATTHEWS 2,968,085
KNITTED PILE FABRIC WITH IMPROVED LONGITUDINAL STABILITY Filed March 6, 1959 BY @fpm ATTORNEYS` nited States Patent() KNI'ITED PILE FABRIC WITH IMPROVED LONGITUDINAL STABILITY Russell R. Matthews, Cornwall on the Hudson, N.Y., as-
signor to The Firth Carpet Company, Inc., New York, N.Y., a corporation of New York Filed Mar. 6, 1959, ser. No. 797,633
1 Claim. (cl. zas-so) This invention concerns itself with knitted pile fabrics, such as floor coverings, and an improved length-wise stability in such fabrics.
Knitted pile fabrics with parallel aligned chain stitches, backing wefts laid in across a given number of chain stitches and pile loops ink such fabrics raised either between chain stitches or from the chain stitches but laid in within said chain stitches are not a new art. In the course of making pile fabrics of types such as are described in the U.S. Springthorpe Patent 1,475,325, Neuman Patent 2,435,897, Neuman Patent 2,229,469, Rice Patent 2,531,- 718, Herrnstadt Patent 2,718,132 and many others, the combination of laid in wefts with parallel aligned chain stitches and raised pile loops are common factors. However, when the above-named construction or similar ones are employed in making pile fabric floor coverings which, out of necessity, have to have backsizing of rubber, starch or plastic materials in order to give further stability to the fabric, it has been found that there is a considerable amount of stretch longitudinally which in turn decreases the width of the fabric during the finishing operation. Also, the wales formed by the parallel aligned chain stitches, particularly in the case of manufacturing oor coverings, are few in numbers per inch because the face yarn for iioor coverings has to be fairly coarse in order to have the proper wearing quality. This coarseness of yarn, in turn, does not permit putting the Wales or lines of chain stitches close enough together in order to prevent certain apertures showing in the backing wefts in the finished fabric.
The importance of this has become exceedingly clear by the fact that backsizing to be put on such knitted fabrics as described in the above-mentioned patents could only be accomplished by keeping the fabric under considerable tension during the backsizing operation in order to have an even distribution of the backsizing material which serves to cover most of the apertures created by the distance of the wales as well as to give good tuft bind between the backing wefts and the face yarn and the warp chains.
It is the improvement of this invention to add an additional warp factor in fabrics as described in the abovementioned patents, as well as in others. The extra warp factor is the equivalent of a stuifer warp such as is well known in Wilton, velvet and other oor covering fabrics but such warp is not bound in by chain stitches but is made straight between the adjacent wales or parallel aligned chains immediately above the weft yarns and underneath the pile loops. These stuffer warp threads, at least one cf which should lie between two adjacent wales in the fabric, are performing numerous functions. One of the functions is to give the fabric improved longitudinal stability or, to express it differently, to prevent excessive stretch in the length-wise part of the fabric when the backsizing is put on. This, in turn, will more or less eliminate shrinkage of the fabric widthwise and permit the fabric to have more courses per inch after it is finished, due to the fact that no stretch takes placel during the backsizing operation.
These and other objects which are appurtenant to my invention may be realized in the accompanying drawings and described in the paragraphs which follow.
In the drawings:
Fig. 1 is a plan view of a fabric which incorporates my invention on a greatly enlarged scale in which the fabric has been opened out and merely shows the backing wefts, the parallel aligned chain stitches and the stufer warps.
Fig. 2 is another plan view but wherein pile loops are incorporated such as they are shown in Patent 2,718,132 but with the addition of this invention.
Fig. 3 is a side view of my invention showing pile loops, one line of chain stitches, side view of the backing wefts and a stuffer warp in which a portion has been backsized.
Referring now to Fig. 1 the reference numbers 10, 11,
12, 13, 14, 15, and 16 designate the wales or parallel aligned warp chains of stitches formed in one combination of a fabric of this invention. Backing wefts 20', 21, 22, 23, 24, 25 and 26 are shown to be laid in across three adjacent wales. Naturally, this is only one example 0f backing wefts laid in across adjacent wales and the invention does not claim this part of the fabric construc tion by itself. Any amount of backing wefts laid across wales, whether it be 3 wales, 4 wales or more, may be utilized in forming the construction of this fabric. may be seen also in Fig. 1 stuler warps 31, 32, 33, 34, 35, and 36 lie between the wales 10, 11, 12, 13, 14, 15, and 16, respectively. It may be noticed that these stuier warps are lying straight above the laid-in wefts and they are not bound into the fabric in any manner except as shown in Fig. 2 where pile threads 40, 41, 42, 43, 44, 45, 46 and 47 are covering such stuifer warps 31, 32, 33, 34, 35l and 36 so that they do not fall out prior to the finishing operation. The side view of Fig. 3 clearly shows a stuffer warp 31 lying adjacent to warp thread 10 and backing wefts 20, 21 and 22 are indicated. Pile yarns 46, and 47, as shown in Fig. 2 of the drawings, are also shown in the side view of Fig. 3 together with stuifer warp 31, wale or chain warp 10. v At first sight of this invention it may be considere obvious to those knowing the art that the addition of another element to this prior art is no novelty but for many years, at least more than two decades, during which knitted carpets have been manufactured one of the major obstacles of making such carpet as compared to woven carpet constituted the fact that no chain stitch was tight enough to prevent longitudinal stretch of the fabric. In order to prevent such stretch an attempt was made to put the yarn used for the warp chains under tremendous tension but extensive stretch during the finishing operation of sizing could not be prevented. Therefore, the inclusion of stutfer warps, which should preferably be made of materials which are unstretchable, such as ramie, jute or Kraftcord paper, were most desirable. Compared to the weaving art as used in Wilton and velvet carpet the knitting machine had no provisions for heddle frames to insert a stuffer warp under and over the backing wefts. Therefore, after much experimentation, it became obvious that while a stuffer warp was necessary in order to strengthen the stability of a knitted pile fabric oor covering, this could be achieved without heddle frames in a manner such as to lay in above the wefts and below the pile such stuier yarns as are necessary to give the fabric the same stability as a woven fabric has. Nat urally, since backsizing of all knitted pile fabric floor covering is practically a necessity, except as in the case of bath mats, this invention was furthered by the finding that even though the stuier warps are now laying in between Patented Jan. 17, 196,1V
the wales they will be bound into the backing put intoV the fabric by virtue of the backsizing used as indicated in Fig. 3 wherein the backsizing is designated by the numeral 50. Furthermore, this then did not only serve 'the purpose of improved longitudinal stability of the `whether it be woven or knitted.
It is necessary to either stitch or tape a knitted fabric with such staffer warps prior to the finishing operation so that these stufer elements are rigidly held in place when the fabric is under tension during the finishing operation. The more stuiers are used between adjacent wales the less shrinkage of the fabric widthwise will take place.
The stuffer warps '31, etc. which are shown in Fig. 1, Fig. 2 and Fig. 3 are individual stuffcr warps, one' lying between two wales immediately above the laid-in weft yarns. Now, in order to make even a denser and more sturdy backing of the fabric there may be two, three or four stuffer warps lying between the wales. Necessity for the number of stuffer ends lying between two wales depends on the number of wales' per inch.
Throughout the specifications I have referred to wales or parallel aligned chain warps intending in these words to dene such chains whether they are composed of a single end or a double end. The expression is also used with the intention of embracing a recognized variation of this type of warp stitches and the variation in the stuffer ends is meant to mean at least one stuffer and between two adjacent wales. Two or more stutter ends may also be used. It is, of course, apparent that variations of this invention may be used in accordance with the above specifications.
A longitudinally stable warp knitted pile fabric comprising a at backing base having parallel, spaced chain stitch warps and a plurality of wefts extending individually back and forth across the chain stitch warps and being bound thereby, stuffer warps between adjacent chain stitch warps, said stuffer warps lying on the wefts, pile loops extending upwardly from said base, each of said pile loops being formed between adjacent chain stitch warps and bound by the stitches thereof, said pile loops extending over the stuier warps, and a backsizing in the fabric base on the side opposite the pile loops, said backsizing penetrating the base so as to secure together the chain stitch warps, the wefts, the stuffer warps which freely rest on the wefts and the lower portion of the pile loops where they are held by the chain stitches.
References Cited in the file of this patent UNITED STATES PATENTS