US2037616A - Knotted carpet and method of manufacturing same - Google Patents

Description

April 14, ,1936. F. BRElTscHDEL KNOTTED CARPET AND METHOD OF MANUFACTURING SAME Filed Mary 5, 3 Sheets-Sheet 1 @WM e d.

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Filed May 3, 1954 3 sheets-sheet 2 0 2v2 ya* 7n ve nio?" WW/W W 14, 1936 A F. BREITSCHDEL. 2,@3796T@ KNOTTED CARPET AND METHOD OF MANUFACTURING SAME Filed May 5, 1934 3 Sheets-Sheet 3 @Wg/www2@ PatentedK pr. 14, 1936 PATENT OFFICE KNOTTED CARPET AND METHOD OF= MANUFACTURING SAME Franz Breitschdel, Katscher, Germany Application May 3, 1934, Serial No. 723,780 In Germany June 1, 1933 6 Claims.

This invention relates in the first place to a method for the manufacture of knotted carpets, especially carpets with Smyrna knots or with Persian knots, on carpet knotting looms. In the known knotted carpets the individual knots or tufts, if they are Smyrna or Persian knots or tufts, are tied around two sets of warp threads lying adjacent to one another. In some cases, however, the tufts are tied only around one set of said threads. It is, besides, generally customary to have two binding wefts follow every row of knots or tufts. With the known knotted carpets a certain phenomenon known under the term shrinkage in midst could not heretofore been avoided, that shrinking consisting in the contractionof the carpet during the weaving so that the breadth of the finished carpet is less than the breadth of the warp in the loom. The shrinking is the stronger, the smaller the number of the knots per square meter of the carpet surface is.

With hand-knotted carpets the shrinking can be compensated, with the aid of a certain amount of additional work, by weaving the carpet broad- -er in correspondence with the `number of knots per unit of surface in the case concerned and, therefore, with the shrinking due to the respective number, so that the finished carpet will have the desired dimension. The conditions are, lhowever, materially ymore difficult when knotted -carpets are to be manufactured mechanically. It has been endeavoured to .compensate the Ashrinking in this case by making the weaving breadth of the carpet knotting machine broader by about 10 cm. than the breadth of the finished -carpet is to be. This shrinkage addition of about 10cm. is, however, with broader carpets entirely insufficient. The amount of the shrinking depends largely upon the numberof the knots per unit of surface in the carpet .knotting machine. The widening of themachine is always the same without any consideration of the number of the knots, in consequence whereof considerable dif- AAiiculties have always been met with in the manufacture of knotted carpets of normal breadth in ,a mechanical manner.

Another drawback which the shrinking entails consists in the fact thatfthe carpets easily become baggy and crooked. Only by wetting and complicated stretching is it possible to Ystraighten the carpets to a tolerable degree, but .it is obvious that such after-treatment causes considerable expense. Furthermore, .it is only in rare cases possible to obviate completely the detrimental consequences of the shrinking by said after-treatment.

Finally, a drawback of the known knotted car- Lpets made on the carpet knotting machine resides in the stripes or-streaks in the goods, this -appearancebeing due to the Aknots lying side by side in straight lines so that the goods look like Axminster carpets.

The chief object of the present invention is to do away with the shrinking of the carpets in the carpet knotting machine; another object is to obviate the production of stripes or streaks in the pattern. According to this invention, each of the warp thread sets around which the indvidual tuft loops are tied consists of a plurality of non-twisted individual threads arranged side by side, and the individual threads of every warp thread set bind crosswise with the binding weft threads following the tuft weft rows. If, thus, every tuft loop has been slung around a warp thread set consisting of two threads, one of these threads will be lifted when the first binding weft thread is being picked, and the other of them will be lifted when the second binding weft thread is being picked. If every one of the warp thread sets consists of more than two threads, a part of the threads of every set will be lifted when lthe first binding weft thread is being picked and another part of said set of threads will be lifted when the second binding weft thread is being picked. The distribution per se may be as desired. If more than two binding weft threads are used, the threads of every warp thread set may also be subdivided into a corresponding number of sets to be lifted in correspondence with the picked weft threads.

I am aware of the fact that it is known to sling the loop of a tuft around a plurality of untwisted warp threads arranged side by side, but with this known method the crossing behind every tuft weft row of the warp threads associated with every loop is lacking, and the shrinking is not obviated.

The particular advantage presented by the present improved method is that the weft threads are maintained in the fabric in stretched state by the strong binding produced by the crossed threads of every set of warp threads, whereby a shrinkage of the weft threads and, therefore, also, shrinkage in the middle of the complete fabric is completely prevented, as intended. Owing thereto, the carpet leaves the loom in exactly the same breadth in which it has been produced in the same, without any consideration of the number of tufts per unit of carpet surface and, thus, also of the number of knots used.

When making use of the present improved method, it is furthermore possible to improve considerably the appearance and the durability of the knotted carpets manufactured on the knotted carpet loom inasmuch as stripes or streaks can be completely avoided. This is attained, according to this invention, by the feature that one part of the warp threads lying in every pile loop is worked in with a somewhat lesser tension than is the other part of said threads. When then the weft threads are being picked, the loose warp threads yield more than the warp threads under tension, in consequence whereof the weft threads, instead of being laid side by side, are partly laid upon one another, so that the gap between the individual tuft weft rows is reduced and the fabric is rendered denser.

vThe amount of the difference in tension between Y the warp threads depends upon the number of tufts per unit of carpet. The smaller this number is, the greater must be the differences between the tensions. For carpets with a medium number of tufts differences of tension of about from 30 to 50% are chosen.

According to a further development of the invention, those warp threads which have the lesser tension are woven into the goods a little more per unit of time than those warp threads that have the greater tension. In this way the greater shrinkage to which the warp threads with the lesser tension is subjected is compensated and the difference of tension in the entire carpet remains one and the. same. The difference in the speed with which both warp thread groups are introduced into the goods depends upon the difference between the tensions to which said groups are subjected.

The method according to this invention can be carried out, for instance, by lifting either all loose warp threads or all tight warp threads over Y the individual binding weft picks in all tuft warp rows. If, for instance, in such a case, the loosely binding warp threads are carried uniformly in all tuft warp rows around the upper portion of the. last binding weft pick preceding a tuft weft row, and the tightly binding warp threads are carried uniformly in all tuft warp rows around the lower portion of said weft pick, a part of this last weft thread is laid over the preceding weft thread and forms thereby a support for the tuft ends of the next following tuft weft row. The carpet pile consisting of these tuft ends receives thereby a particularly good foundation and the pile bunches spread widely apart. Owing to the tuft weft rows following one another closely and to the upright position of the pile the streakiness of the pattern is either completely avoided or at least very considerably reduced, and the strength of the fabric is at the same time improved.

One manner of carrying out the present improved method especially with they View to do away with the streakiness is the following:

The weft picks are manipulated so that the loose warp threads are lifted in every second tuft warp row over the rst weft pick, whereas the tight warp threads are lifted over the second weft pick, and in the adjacent tuft warp rows the tight warp threads are lifted over the first weft pick and the loose weft threads are lifted over the second weft pick. Owing thereto, the hold which the weft picks preceding tuft weft rows afford the tufts following them is different in the adjacent tuft warp rows, in consequence whereof the position or" the tuft in the adjacent tuft warp rows varies and the ends of every tuft weft row do not form a straight line, but a zigzag line whereby the streakiness of the goods is obviated.

In order to make my invention more clear, I refer to the accompanying drawings, in which Figure l is a plan of a portion of a mechanically knotted carpet manufactured according to the known manner, the figure being drawn to a greatly enlarged scale. is a transverse Figure .4 section through Figure l. Figure 3 is a view similar to Figure l illustrating the improved method according to they present invention. Figure l is a transverse section through Figure 3; Figures 5 and 6 show a modification of the improved method, likewise in plan and in transverse section, and Figures l and 8 show another modification. Figure 9 is a perspective representation of a piece of a knotted fabric manufactured according to the method illustrated in Figures 3 and 4, the scale being still larger than in these figures. Figure 10 is a view similar to Fig. 9 illustrating the tying with tight and with loose warp threads, and Figure 1l is a view similar to Figure 10 illustrating the manufacture with staggered tufts.

In all figures, the first tuft weft row is denoted A, the second B, and in Figures 9-11 where there is a third tuft weft row C denotes this row. Everyone of said rows is followed in the usual manner by two binding weft picks l and 2. As in the examples shown the tufts have the shape of Smyrna knots, two loops are present in each tuft. In Figures 2, 4, 6 and S, the dots lying in the two loops of every tuft, represent the warp threads around which the tuft has been slung. Each of said figures comprises three tuft warp rows I, II and III.

Figures l and 2 illustrate the known method, as already stated in the short description of the figures. There are in this case two warp threads d and g associated with every tuft so that there is only one warp thread in every loop. There has been lifted, for instance, the warp thread d in each of the tuft warp rows I, II and III when the first binding weft thread has been picked, and the warp thread g has lifted when the second binding weft thread has been picked. With this method the known shrinking takes place.

In the improved method, however, as illustrated in Figures 3-8 there are sets of warp threads, each of which comprises two threads, as in Figures 3-6, or three threads, as in Figures 7 and 8. Every tuft is tied around two threads, namely, d and e, or g and h respectively. the knotting proper the two threads constituting a set are worked in pairs so that a Warp thread set consisting of two threads lies in every loop. If now the first binding weft thread is picked,

then, in the method carried out according to i Figures 3 and 4, in every tuft warp row I, II and III only the thread d of the left-hand warp thread and only the thread h of the right-hand warp thread are lifted. When thereafter the second binding weft thread is picked only the thread e of the left-hand warp thread and only the thread g of the right-hand warp thread are lifted. 'Ihe two threads d and e, as well as g and h, of every set of warp threads bind with one another crosswise when the binding weft threads are picked. This crossing of the threads associated with one set of threads causes an intimate connection of the binding weft threads and prevents the shrinking of the carpet.

Also in the modification illustrated in Figures 5 and 6 every set of warp threads consists of two threads d and e, or y and h. The binding-in of the individual threads of every set of warp threads is in this modification different, as regards two adjacent tuft warp rows. With the two outer tuft warp rows I and III the two outer threads d and h are lifted during the picking of the binding weft thread I, but when the binding weft thread 2 is picked the two inner threads In carrying out /fe and g are lifted. The reverse is the case with the middle tuft warp row II.

' In Figures 7 and 8 each of the two warp thread sets around which every tuft is tied consists of three threads d, e and f, or g, h and i. Every loop of the tuft surrounds, thus, three threads. When the binding weft thread I is being picked, there are lifted, with the outer tuft warp rows I and II, the two outer threads d and e, as well as h and i, and the binding weft thread 2 extends below the inner threads f and g. It is a matter of course that the subdivision of the threads lifted at the picking of the first and the second binding thread may be otherwise, as desired (see the middle tuft row II, Figure 7). Furthermore, the number of the threads constituting the individual sets may be larger than three. It is, however, always an essential point that the plurality of the warp threads surrounded by every loop is bound-in crosswise with the binding weft threads following every tuft weft row.

.Inthe perspective illustration Figure 9 which corresponds in principle with Figures 3 and 4, there is, besides the two tuft weft rows'A and B, a third such row C located at the side of the row B. The weft threads I and 2 lie in the same horizontal plane, and the tuft ends which are not backed at the weft threads 2 are a little inclined.

A similar mode of carrying out the improved method is shown in Figure l0 in which in all tuft warp rows I, II and III the first and the third warp threads d and g are loose and the second and the fourth warp threads are tight. In all tuft warp rows the tight warp threads e and h are lifted by the binding weft thread I, and the loose warp threads d and g are lifted by the binding weft thread 2. As Figures 9 and 10 show, the loose warp threads yield in both cases. The binding weft thread I is, therefore, pressed downwardly and the binding weft thread 2 is pressed upwardly over the rst. The tuft weft rows B andrC approach the tuft weft row A considerably more than has been possible with the fabrics manufactured after the known method. At the same time the weft thread 2 which lies over the weft thread I constitutes a secure support for the pile-forming ends of the tuft rows B and C and spreads the pile by its pressure.

Finally, concerning Figure 11, the distribution of the tension, and the intertying are as follows: With all tuft warp rows I, II and III the two outer warp threads d and h are loose and the two inner warp threads e and g are tight. In the tuft warp row I the two outer loose threads d and h are lifted when the binding weft thread I is picked and the two inner tight threads e and g are lifted when the binding weft thread 2 is picked. The tuft warp row III is formed in the same manner, whereas in the tuft warp row II the binding weft thread I extends below the tight warp threads e and g and the binding weft thread 2 lifts the loose warp threads d and h. As in this case the loose warp threads also yield, in this type of weaving the binding weft thread I in the tuft warp row I is lifted a little; the binding weft thread 2, however, is a little depressed, this thread lying then partly below the thread I. The same is true in the tuft warp row III. In the tuft Warp row II, however, the binding weft thread I lies below and the binding weft thread 2 lies above and partly over the binding weft thread I, in consequence whereof the tufts of the rows B and C where they engage the preceding binding weft threads 2 in the tuft warp rows I and III are subjected to a different resistance than in the tuft warp row II. The tufts BI and BIII, as welll as CI and CIII, assume, therefore, a different position from the tufts BII and CII whereby the ends of the adjacent tufts in the tuft warp rows I and II, or II and III respectively, which are visible as pile, are staggered with respect to one another so that the thus obtained zig-Zag arrangement does away with the streakiness.

The invention is by no means limited to the few examples shown; it is applicable to all knotted carpets with different tensions of the warp threads. It is especially irrelevant whether or not in the individual tuft warp rows the'iirst d andthe third g warp thread or the first d and the fourth h, warp thread or the second e and the third g warp thread are loose or stretched. The method according to this invention is also applicable if by the first weft pick I all loose warp 9 threads and by the second pick 2 all tight warp threads are lifted. The invention can, finally, be realized also where only one warp thread lies in a tuft loop, in that a portion of the warp threads is subjected to a lesser tension than another portion of the same, and then the warp threads are interwoven crosswise with the binding weft threads. In the latter case the inner connection of the carpet is very loose, it is true, and the arising of a shrinkage is practically unavoidable so that it is desirable to work with warp threads of different tensions only if every warp thread set embraced by a tuft loop comprises at least two individual threads.

If the warp threads have different tensions the further advantage is attainable that finer or coarser binding weft threads may be picked, just as required. If the tension is very slight, the weft thread may be strong, but if the tension is stronger, a ne weft thread may be used. But the number of the knots per unit of carpet surface may be the same in both cases.

For the rest, I point also to the advantage that the carpet fringe which consists, as is known, of the warp thread ends that extend beyond the edge of the carpet presents a better appearance than the fringe obtained with the known method, in that it looks finer and thicker, the reason being that the number and the Iineness of the threads is considerably greater than with the known method.

The invention is applicable also for the manufacture of knotted carpets on manually operated looms.

I claim:

1. A carpet having rows of tufts, each tuft having tow loops, at least two weft pick threads running between each pair of tuft rows and parallel to the tuft rows, and at least tow individual warp threads extending through each of such loops and interwoven with said weft pick threads, the warp threads in any one loop having different tensions, whereby one of the weft pick threads between each pair of tuft rows is displaced so as at least partly to overlie the other weft piek thread, so that the tuft rows are drawn closer together.

2. In a carpet having rows of tufts, each tuft having two loops, at least two weft pick threads running between each pair of tuft rows and parallel to such rows, and at least two individual warp threads in each of said loops, one warp thread in each loop passing beneath the adjacent weft pick and above the more remote weft pick while another warp thread in the same loop passes over the adjacent weft pick and beneath the more remote weft pick, the warp threads in any one loop having different tensions, whereby Said warp threads rmly bind the weft threads and maintain them in the fabric in a stretched state so that shrinkage is prevented, and whereby the weft pick threads between each pair of tutt rows are displaced so that one of said threads at least partly overlies the other thread so as to bring the tuft rows closer together.

3. In a carpet having rows of tufts, each tuft having two loops, at least two weft pick threads running between each pair of tuft rows and parallel to such rows, and at least two individual warp threads in each of said loops, the warp threads in any one loop having different tensions, and the warp threads with the same tension passing simultaneously above or beneath the said weft picks, whereby said warp threads rmly bind the weft threads and maintain them in the fabric in a stretched state so that shrinkage is prevented, and whereby the weft pick threads between each pair of tuft rows are displaced so that one of said threads at least partly overlies the other thread so as to bring the tuft rows closer together.

4. In a carpet having rows of tufts, each tuft having two loops, at least two weft pick threads running between each pair of'tuft rows and parallel to such rows, and at least two individual warp threads in each of said loops, the warp threads in any one loop having diiierent tensions, the warp threads with the lower tension in each loop passing beneath the adjacent weft pick and above the more remote weft pick while the warp threads with the stronger tension in each loop pass over the adjacent weft pick and beneath the more remote weft pick, whereby said warp threads firmly bind the weft threads and maintain them in the fabric in a stretched state so that shrinkage is prevented, and whereby the weft pick threads between each pair of tuft rows are displaced so that one of said threads at least partly overlies the lower tension passing beneath the adjacent weft pick and above the more remote weft pick while the warp threads with the stronger tension pass over the adjacent weit pick and beneath the more remote weft pick, and in the remaining loops of each tuft row the warp threads with the stronger tension passing beneath the adjacent weft pick and above the more remote weft pick while the warp threads with the lower tension pass over the adjacent weft pick and beneath the more remote weft pick, whereby said warp threads firmly bind the weft threads and maintain them in the fabric in a stretched state so that shrinkage is prevented, and whereby the weft pick threads between each pair of tuft rows are displaced so that one of said threads at least partly overlies the other thread so as to bring the tuft rows closer together,

6. A method for the manufacture of carpets having rows of tufts, each tuft having two loops, weft pick threads running between and parallel to the tuft rows, and at least two individual warp threads extending through each of such loops, consisting in interweaving said Warp threads with said weft pick threads, during such interweaving appying different tensions to the warp threads in any one loop, and introducing the warp threads with the lower tension faster into the goods than the warp threads with the stronger tension, whereby the weft pick threads between each pair of tuft rows are displaced so that one of said threads at least partly overlies the other thread, so that the tuft rows are brought closer together.

FRANZ BREITSCHDEL.

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