US3892432A

US3892432A - Continuous yarn drawing method and apparatus

Info

Publication number: US3892432A
Application number: US447099A
Authority: US
Inventors: George A Ingus
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-03-01
Filing date: 1974-03-01
Publication date: 1975-07-01
Anticipated expiration: 1992-07-01

Abstract

A technique for continuously supplying uniformly dyed or natural yarn to a fabric manufacturing or other end use facility is disclosed. Yarn is supplied from active and inactive packages of the ''''buried tail end'''' type mounted on a creel, and passes to the manufacturing location through apparatus including a tensionreducing guide, a tension detector and an automatic knotter. The inactive yarn element is fed from its package on a parallel path to a point beyond the knotter, where it is held temporarily in a stationary guide post while the active yarn element is fed to the end use point. Upon detection of a significant change in the tension of the active yarn element, the knotter is activated and proceeds to sever the active yarn and tie a suitable knot to the held end of the inactive yarn element. This establishes a new but essentially coincident active yarn element to continue the yarn feed, with the formerly active element assuming inactive status until another tension change in detected.

Description

[ July 1, 1975 CONTINUOUS YARN DRAWING METHOD [57] ABSTRACT AND APPARATUS A technique for continuously supplying uniformly Inventor: George A. lngus, 44 Birch Sr, dyed or natural yarn to a fabric manufacturing or g l d Cliff NJ 07632 other end use facility is disclosed. Yarn is supplied from active and inactive packages of the buried tail Filed: 1974 end" type mounted on a creel, and passes to the man- Appl 447,099 ufacturing location through apparatus including a tension-reducing guide, a tension detector and an automatic knotter. The inactive yarn element is fed from U-S- R its p g an a parallel p to a point y d the lift. notter' ere i is temporarily in a nary Fleld of Search 289/2 guide post while the active yarn element is fed to the 242/355; 28/47-49 end use point. Upon detection of a significant change in the tension of the active yarn element, the knotter References cued is activated and proceeds to sever the active yarn and UNITED STATES PATENTS tie a suitable knot to the held end of the inactive yarn element. This establishes a new but essentially coinci- United States Patent lngus 289/3 289/l8 X dent active yarn element to continue the yarn feed, 239/3 X with the formerly active element assuming inactive 5 status until another tension change in detected.

Kostelecky...H.......r.i..... Horatachke 16 Claims, 7 Drawing Figures Primary ExaminerLouis K. Rirnrodt Attorney, Agent. or FirmGottlieb. Rackman Reisman & Kirsch CONTINUOUS YARN DRAWING METHOD AND APPARATUS This invention relates to fabric manufacturing in general, and to the continuous and uninterrupted supply of yarn for such manufacturing in particular.

In the textile industry, the importance of avoiding stoppages and "down time" on various fabric manufacturing machines, and at the same time assuring a high quality product, cannot be exaggerated. Whether one considers knitting machines, looms for weaving, socalled warp-makers or winding machines, among others, it is both an economic and quality control necessity to provide for a continuous supply of yarn to these machines and their corresponding processes. Should such machines require interruption in their operating cycles, either because ofyarn failures (e.g., ruptures or fraying) or because of a damaged or defective yarn element, the result is virtually the same production of an entire machine may be curtailed because perhaps only one yarn package out of 24, 36, 48, etc. packages has caused trouble. And when the statistical probability of such failure is multiplied by the number of packages in use on one or more operating machines, the potential for substantial delays in production is apparent.

A particular aspect of this problem is the requirement in this industry for the continuous supply of uniformly dyed yarn. To achieve this, two basic types of yarn packages are available, namely one in which the end of the yarn is ramdomly imbedded at the bottom of the cone or package around which the yarn is wound (the buried tail end package), while the other type of package has the end of the yarn hanging free outside the core of the package (the exposed tail end" package). In dyeing yarns, the conventional practice is to package dye," that is, to mount the yarn package on a perforated sleeve and to force the dye liquor out through the sleeve perforations from the inside. This fully and uniformly dyes a buried tail end package (whose end is dyed together with all of the other yarn elements), but does not completely uniformly dye an exposed tail end package (whose end is somewhat remote from the edge of the sleeve and is thus differently exposed to the dye liquor, than is the main body of the package on the sleeve.

When it then comes to the yarn feeding or drawing step, the completely uniformly dyed buried tail end package is ideal to produce a fabric having no nonuniformly dyed segments, flecks" or streaks, but it has been impossible to draw such yarn continuously, due primarily to the inaccessibility of the end that is, when the end of a buried tail end package is about to be fed to the fabric manufacturing point, that particular feed must be temporarily halted while a new yarn pack age is mounted to take the place of the exhausted package. On the other hand, the exposed tail end package can be continuously drawn because its end can be physically coupled to the forward end ofa spare or succeeding yarn package, thus insuring continuity of yarn supply. But, of course, it will be recalled that the exposed tail end package is not completely uniformly dyed, thus causing some of the yarn fed to the manufacturing location to be non-uniformly dyed and causing potential seconds" or damaged goods in the produced fabric. To avoid this problem, the spare yarn packages may be tied to the active exposed tail end package at the last uniformly dyed point thereof, thereby wasting yarn and making coupling of yarn elements difficult. Finally, it is also possible to utilize costly auxiliary dyeing to eliminate this problem, but obviously such an approach is not economically feasible. These same basic problems exist with respect to natural yarn packages of the buried tail end type, where continuous drawing has not heretofore been achieved the difficulties indicated above regarding dyed packages do not exist where natural yarns are being used.

The prior art has not really addressed itself to the foregoing problems. The textile industry has, to a great degree, simply lived with the problems of either having continuous drawing of only undyed or partially dyed goods, or else having a discontinuous (i.e., interrupted) drawing of uniformly dyed or natural goods as described above. No satisfactory solution has been proffered to achieve continuous drawing of buried tail end yarn packages. While there has been some recognition in the industry that yarn feed interruptions were to be avoided through the use of an automatic knot tying device, no attempt has been made to utilize such a technique in providing a continuous and uninterrupted supply of uniformly dyed yarn or natural yarn from buried tail end packages.

It is therefore an object of this invention to obviate one or more of the aforesaid difficulties.

It is also an object of this invention to provide apparatus to supply uniformly dyed yarn to a fabric manufacturing or other comparable end use point on a continuous basis.

A further object of this invention is to continuously draw yarn from buried tail end yarn packages without interrupting the drawing to change from an exhausted package to a fresh one.

Other objects, features and advantages of this invention will become apparent from a consideration of a particular illustrative embodiment of this invention, wherein yarn is fed to a manufacturing location (e.g., a knitting machine, a loom, etc.) from a conventional side creel. Multiple yarn packages can be mounted on the creel to feed yarn to several different feed points in the manufacturing process for example, if a knitting machine is involved (and this invention is applicable to all types of machines and devices requiring one or more yarn feeds), there may be anywhere from 24 to 96 simultaneous yarn packages being fed to the knitting needles for production of fabric. Each feed to which this invention is applicable would have an active and inactive package concurrently associated with it, the active package actually furnishing yarn being used to form the finished product, and the inactive package being fed in a parallel path with its companion active package, but being held short of the manufacturing location awaiting ultimate transfer to active status.

A typical feed path for the active yarn element would be from the yarn package on the creel to a conventional tension-limiting guide device consisting of two parallel disks or plates, one of which is stationary and the other of which is lightly springbiased toward the other; the yarn element passes between the two disks and is guided by the gentle holding action exerted on the yarn by the spring-biased disk. These devices, which are conventional, also serve to limit the amount of tension introduced into the drawing process. From the guide, the active yarn element passes a tension detector which monitors the level of tension in the yarn.

This device can take the form of a spring-biased rod which can detect a reduction in tension caused by a break or loosening in the yarn or its running out, causing the rod to move in the biasing direction and activate a contact, or an increase in tension based on a tighten ing of the yarn element (thereby forcing the rod to move in the opposite direction against the spring bias until another contact point is reached).

The steps to be taken in response to such changes in tension will occur at the next stage in the feeding process, namely at an automatic knotter. Such knotters are well known in the industry, although not for the context or combination disclosed herewith. Specifically, either of several knotters may be used, such as those which tie "silk knots or fishermans knots"; the principles of operation of either of such knotters are substantially the same insofar as they relate to this invention. In the silk knot tying embodiment, the active and inactive yarn elements pass through the same groove on opposed side plates of the knotter. The active yarn element then passes directly to a manufacturing location, such as looms, knitting machines, etc., perhaps through a storage feed windup device.

The inactive yarn element, traveling in the same grooves of the knotter plates, passes to a tensionlimiting guide of the type described previously, namely a spring-biased plate and a stationary plate, with the end of the inactive yarn element held therebetween. The inactive yarn element is fed to the holding guide over a path essentially identical to the path described above with respect to the active yarn element, that is, from a yarn package which is substantially adjacent to the active yarn package on the creel and then through a companion guide element and tension detector to the common feed groove of the knotter, ultimately arriving at the remote guide element noted above. With this operational geometry, the active yarn element is proceeding to the end use location and is being consumed during fabric production, while the inactive yarn element, lying parallel to the active element, is stationary and is available to be transferred to active status as will be described.

Upon detection of a change in tension in the active yarn element (e.g., the active yarn breaks, causing a reduction in tension, or a snag or a pull occurs, thereby increasing the tension), the automatic knotter device is activated in response to a signal from the tension detector. This causes the knotters trigger to be pulled and the knot tying mechanism ultimately severs the active yarn element at a point between the rear and forward plates of the unit. As part of the same process, the knotter attaches the previously held end of the inactive yarn element to the trailing end of the formerly active yarn clement, tying a knot which is nearly indistinguishable from the continuous diameter of the yarn element. The newly formed active" yarn element consists of the for ward segment of the previously active yarn element, which is now coupled to the end of the formerly inactive yarn element which had been held by the tension guide beyond the knotter. The fabric forming or other process can now continue uninterruptedly, with the yarn being continuously fed to the manufacturing location from the formerly inactive yarn package. The other previously active package can now be replaced (if its yarn had been exhausted prior to switch-over) or inspected for defects (if a snag or other tensionproducing factor caused the switch-over). In the latter case, the now hanging forward end of the formerly active yarn package must be placed into the tension guide so that it. can await the next switch-over.

It is therefore a feature of an embodiment of this invention that yarn is fed from multiple packages on a creel over parallel travel paths to permit transfers to be made between yarn elements in response to a feeding problem in connection with the active one of said yarn elements.

It is another feature of an embodiment of this invention that an active yarn element passes through a tension detector and an automatic knotter device to be severed and coupled to a normally inactive yarn element upon the detection of a change in tension in the active yarn element.

It is also a feature of an embodiment of this invention that yarn packages having a buried tail end are utilized in conjunction with an automatic knotter to achieve continuous drawing of uniformly dyed or natural yarn packages.

These and other objects, features and advantages of this invention will become more readily understood when considered in connection with a presently preferred, but nonetheless illustrative, embodiment of the invention as explained in the following detailed description and as shown in the accompanying drawing, wherein:

FIG. 1 illustrates the feed paths of active and inactive yarn elements from yarn packages on a creel through guiding apparatus to an automatic knotter of the silk knot type, leading to end use equipment;

FIG. 2 shows the horizontal feeding of yarn from side-spaced packages feeding towards each other, suitable for use with an automatic knotter tying a fishermans knot;

FIG. 3 is comparable to the illustration of FIG. 2, but showing the feeding paths after the active and inactive yarn elements have changed their functional positions, with the knotter itself having been rotated about its vertical axis;

FIG. 4 is a diagrammatic view of the orientation of the active and inactive yarn elements prior to tying a knot therebetween, taken from the perspective 44 of FIG. 1 in the direction of the arrows, with the automatic knotter being shown by the symbolic block and with the inactive yarn being held in a tension limiting device;

FIG. 5 shows the orientation of the active and inactive yarn elements at the beginning of a silk knot-tying cycle, with a loop of the active yarn element nesting within a loop of the inactive element;

FIG. 6 is an enlarged view showing the formation of a silk knot, with the various loops of the yarn elements occupying the positions shown; and

FIG. 7 is a view of the yarn elements following the tying of the knot and the cutting off of corresponding ends and loops, with the active yarn supply now coming from the formerly inactive yarn element.

Referring to FIG. 1, a perspective view of the salient portions of the invention, as applied to the feeding sequence of a fabric manufacturing process, is illustrated. For example, the end use point (not shown) could be any one of a number of manufacturing machines, including looms, knitting machines, warp-makers, etc., all having in common the feeding of one or more yarn elements to them. All such mechanisms require that for optimum continuity and efficiency of operation, the

yarn feeding should be done on an uninterrupted basis, and in particular with relation to the uniformly dyed yarn packages represented by buried tail end yarn packages, continuity has not heretofore been available in this industry.

The view of FIG. 1 includes a representational and fragmentary showing of a side creel on which a number of buried tail end yarn packages are illustratively mounted. Included among the packages is package 12 for the initially inactive yarn element, package 14 for the initially active yarn element and package 16 which is a spare yarn package, which can ultimately replace one of

yarn packages

12 or 14 when it has been exhausted during the manufacturing process. Considering the active yarn package 14, yarn element l8 passes from that package to tensiondimiting guide member 24 mounted on post 28 shown in fragmentary form in FIG. I. Yarn 18 is held between

plates

24A and 24B ofguide 24, with plate 248 being lightly spring-biased towards plate 24A by means of spring 24C, in conventional fashion. This guide serves to direct the travel of yarn element 18 and to limit the tension introduced into the feeding process by the other portions of the apparatus. From guide 24, yarn 18 passes to tension detector 32, which can conveniently take the form of a slot 32A in which rod 32B is slidably mounted. Within slot 32A (but not shown in FIG. 1) is a suitable biasing means, such as a spring, urging rod 32B in the direction indicated by arrow 32D. Yarn element 18 passes around rod 328 and then is reverse wound around rigid post 33. Due to the light spring bias on rod 32B in the direction indicated by arrow 32D, rod 32B remains in contact with yarn element 18 and thereby monitors its tension. Should yarn element 18 break or become loose, rod 328 would slide within slot 32A in the direction indicated by arrow 32D and thereby engage an appropriate contact (not shown) within slot 32A to activate knotter 34. Similarly, should there be excessive tightening of yarn element 18, such as would be attributable to a snag or pull which increases the tension in the yarn element, this will drive rod 328 in the direction indicated by arrow 32C (against the spring bias); this will also activate knotter 34.

Active yarn element 18 then passes downward toward automatic knotter 34. This is a device which automatically ties a knot between two concurrently trave1 ing or adjacent yarn elements, with the knotter 34 as illustrated in FIG. 1 being of the type that ties a "silk knot", and being generally available from Asquith Electrics (Colne) Ltd. of Lancashire, England. Knotter 34 consists of base plate 36 on which bracket 38 is mounted. Bracket 38 provides support for mounting arm 40 of the knotter. Arm 40 in turn is coupled to lower grooved plate 42 and upper grooved plate 44, between which travel the

yarn elements

18 and 20. As noted in the FIG. 1, active yarn element 18 passes downward through groove 42A of lower plate 42 of the knotter and then, as indicated by the arrow at the bottom of FIG. 1, proceeds to the manufacturing or other end use location (not shown).

The path of the inactive yarn element (i.e., the yarn element which is not actively being consumed at the manufacturing location or end use point) starts at yarn package 12 on creel l0. Yarn element 20 proceeds first to tension-limiting guide 22, comprising stationary plate 22A and movable plate 22B which is biased towards plate 22A by means of spring 22C; guide element 22 is mounted on post 26. Yarn element 20 then passes through tension detector 30, which is comparable in structure and function to detector 32, described above with respect to yarn element 18. Thus, rod 30B rides in slot 30A, with normal spring bias for rod 308 being provided in the direction indicated by arrow 30D. A reduction in tension in yarn element 20 causes rod 308 to move to the right (arrow 30D), while an increase in tension in yarn element 20 urges rod 308 to the left (arrow 30C); appropriate contacts within slot 30A are thereby engaged to activate knotter 34.

Inactive yarn element 20 then proceeds through grooves 44A and 42A of knotter 34, and is held in tension-limiting guide 50 which is mounted on post 52. This guide comprises a stationary plate 50A and a coaxial plate 503 which is biased toward plate 50A by spring 50C. The lower end of yarn element 20 is held between

plates

50A and 508 by virtue of the springbiasing effected by spring 50C, and this holding continues until inactive yarn element 20 is called upon to assume active status as will be described below.

Yarn packages l2, l4 and 16, and others not shown which can be utilized with this invention, can be of the buried tail end type, with the distant end of the yarn being imbedded randomly within the package of yarn elements on a cone or cylinder for storage purposes. During the dyeing process (where dyed yarn rather than natural yarn is required), the entire package will have been uniformly dyed, including the buried tail end. The yarn packages are then mounted on creel 10 for introduction into the fabric forming or other manu facturing process, and it will be assumed for the balance of the description that buried tail end yarn packages of uniformly dyed yarn will be feeding yarn elements from creel 10 towards the end use point over the indicated travel paths.

A typical cycle of operation of the elements of the invention can be understood by considering the two paths followed by

yarn elements

18 and 20, and the respective roles played by these yarn elements at different stages during the feeding process. Consideration of FIGS. 1 and 4-7 are relevant to an understanding of the process. The specific apparatus of FIG. 1 has already been generally described, and during the feeding process, yarn element 18 (the active element) is fed from yarn package 14 through tension-limiting guide 24, past tension detector 32 and through grooves 44A and 42A to the end use point. At the same time, inactive yarn element 20 passes from adjacent yarn package 12 through tensionlimiting guide 22, past detector 30 and through the same grooves 44A and 42A of knotter 34 to the point where its end is held between

plates

50A and 50B of tension-limiting guide member 50. Accordingly, as can be appreciated from a review of FIG. 1, active yarn element 18 and inactive yarn element 20 travel through nearly parallel paths and through grooves 44A and 42A of knotter 34, with the divergence between them occurring after knotter 34, namely with inactive yarn element 20 being held in a waiting position by guide 50 and active yarn element 18 passing to an end use location. In this posture, yarn element l8 continues to be used up at the end use location, for example at a knitting machine, a loom or the like, or perhaps being wound up on a storage feed" device which is utilized in industry to provide a continuous supply of yarn having uniform tension to knitting needles, looms, etc. Inactive yarn element 20 is, at the present time, merely waiting' to be switched over to active status when there is some problem with or change in the feeding of active yarn element 18.

The change from active yarn element 18 to inactive yarn element 20 takes place in response to the detec tion by tension detector 32 of a change in tension in active yarn element 18. Such a change could result in response to any one of a number of occurrences with respect to that yarn element, such as rupture (tension exceeds the tensile strength of the yarn), loosening (excessive tension buildup causes the yarn to stretch and then become slack or the yarn in the package is fully consumed) or tightening of the yarn. Detector 32 need not distinguish between these various conditions, and only need determine that there has been an improper and undesirable tension change. If yarn element 18 has ruptured, clearly that yarn feed will be interrupted at the end use point and the process will have to be interrupted in order to insert a new yarn element into the feed path; if there has been a stretching of yarn element 18, caused for example by a snag or pull in the yarn, defects will also result at the fabric forming location, also necessitating a change in the yarn feed. When such a change in tension of active yarn element 18 occurs, detector 32 transmits its responsive signal to piston 48, which may, for example, take the form of a solenoid controlled plunger 48A. Plunger 48A is physically coupled to trigger 46, and in response to an activating signal from tension detector 32, plunger 48A is withdrawn into the main body of piston 48, thereby causing trigger 46 to be activated and to move to the phantom position illustrated at 46 in the lower portion of FIG. 1. This is the manner in which automatic knotter 34 is activated, causing the yarn feeding to be transferred from active yarn element 18 to inactive yarn element 20.

The technique for transfer, which involves the severing of active yarn element 18 and transferring the forward end of that element to the previously inactive element 20, is generally and diagrammatically illustrated in FIGSv 4-7, in which the knot-tying and ultimate severing of dangling or unused yarn elements is illustrated. Starting from the position shown in FIG. 4, automatic knotter 34 is symbolically illustrated by a block, and can be taken to mean the knotter shown in greater detail in FIG. 1. As has previously been stated, the knotter can be of several types, including those which tie a silk knot or a fisherrnans knot or other suitable knot; in the case of the illustrations of FIGS. 4-7, the silk knot embodiment of an automatic knotter is described and shown. In FIG. 4, active yarn element 18 is shown passing through knotter 34 and, as indicated by the arrow adjacent to that element, on to an end use point in the fabric forming process. Inactive yarn element 20 also passes through knotter 34, but its lower end is held by tension guide 50, mounted on post 52 and specifically between stationary plate 50A and movable plate 508 which is biased toward plate 50A by means of spring 50C. This is the initial feeding posture of

yarn elements

18 and 20, comparable to the more detailed perspective view of FIG. 1. Subsequently, when tension detector 32 detects a change in tension in active yarn element 18, piston 48 is activated, causing plunger 48A to pull trigger 46 of knotter 34. In the preliminary activation of knotter 34, a loop is formed in corresponding segments of

yarn elements

18 and 20. This initial loop formation is indicated in FIG. 5, with active yarn element having a loop 18A formed and nesting within a corresponding loop 20A in inactive yarn element 20. The feed of active yarn element 18 to the end use point has not yet been physically interrupted and the knotter 34 has not yet severed the active yarn element at this point, the knot tying process has begun without any such severing.

Moving on to a consideration of FIG. 6, a more advanced stage in the formation of the silk knot is illustrated.

Loops

18A and 20A in active and

inactive yarn elements

18 and 20 respectively have moved to a further inward position in the knot 19 which is in formation. Additional loops have been formed by the convolution of

yarn elements

18 and 20, as caused by the internal mechanism of the automatic knotter 34, in a manner which is well known to those skilled in the art. As illustrated in FIG. 6, active and inactive yarn elements form an interior half loop in knot 19 by the formation of opposite loops 18B, 208, which lead respectively to a projecting loop 19C consisting of

turns

18C and 20C of the respective yarn elements. The projecting yarn loop extends under the upwardly extending strands of yarn elements 18 and 20 (identified as 18, and 20,) and form an outside loop toward the left of knot 19, namely at 18D and 20D. The remainder of knot 19 is formed by the further convolution of the active and inactive yarn elements around and under projecting loop 19C, forming peripheral loop members 1815 and 20E. The yarn elements extend from this last peripheral loop through and under the yarn elements formed into the interior loop in knot 19 and out and down as

yarn segments

18 and 20 at the lower left of FIG. 6. These various loops and convolutions in knot 19 are formed in response to the mechanisms contained within automatic knotter 34, and are provided herein as a diagrammatic representation of the manner of knot formation.

The completed knot 19 is better understood from a consideration of FIG. 7. Between the times indicated in the view of FIG. 6 and that of FIG. 7, the automatic knotter 34 has pulled the various convolutions and loops tight, such that loop 19C has been pulled outwardly and to the right of knot 19, and the upward end pairs 18, and 20, and the

downward pair

18 and 20 have been pulled in the respective upward and down ward directions to tighten the knot. As can be appreciated from a consideration of the preliminary knot posture shown in FIG. 6, the tightening of the various loops and convolutions leads to certain dangling" yarn elements and to a projecting and potentially harmful and extraneous loop 19C. Knotter 34 is therefore designed to sever these unwanted portions of the yarn elements. In particular, loop 19C is severed at four locations, two points toward the core of knot 19 which had formed loop portion 18C, and two corresponding portions of yarn element 20 which had formed loop portion 20C. This is illustrated in FIG. 7 by the showing of loop 19C in phantom, to suggest the severing of these segments. In addition, the active yarn element is now to be formed of the formerly advancing lower end 18 of previously active yarn element 18, coupled (by knot 19) to the downwardly hanging end 20 of formerly inactive yarn element 20. This is indicated by the relatively straight yarn element portion 20 -18 proceeding vertically downward in FIG. 7. The now unused and

dan gling portions

18, and 20 of corresponding yarn ele ments 18 and 20 are obviously not needed and are extraneous to the continuity of the yarn feeding process;

they are accordingly severed by automatic knotter 34, and such severing is indicated by the separation between each of

segments

18, and 20 and the corresponding remaining segments which had been coupled to those yarn elements but which are now in the interior of knot 19.

The portion of the yarn represented by segment 20 is merely that portion between knotter 34 and tension guide 50 which had held that portion of yarn element 20 before switch-over occurred. Accordingly, that portion is merely removed from the process and discarded, or indeed it may fall away of its own accord. Segment 18,, however, extends upward to still existent yarn package 14, at least in the case where there has only been a rupture of other problem with yarn element 18 but where yarn package 14 has not yet been fully consumed. Accordingly, such yarn element 18,, extending backwards to yarn package 14, must be rethreaded through guide 24 and past detector 32 and down through grooves 44A and 42A of knotter 34 and then must be inserted within tension guide 50, which holds this now inactive end of yarn element 18. This, of course, would only be done after inspection of yarn element l8 and a determination of any problems associated with that yarn element for example, ifa snag or other defect were found, it would have to be cut out or otherwise eliminated, or indeed the entire yarn package 14 might have to be replaced by another yarn package. Similarly, if all of the yarn of package 14 had been consumed, a new yarn package (such as spare package 16) would have to be replaced on the spindle of creel previously occupied by yarn package 14. This now forms the inactive yarn element, while the active yarn path is now occupied by element 20, passing down through the path previously occupied by yarn element 18 as illustrated in FIG. 1.

The invention now operates to monitor the tension in yarn element (the currently active element) and it is detector 30 which is responsible for detecting changes in tension in this active yarn element 20 to thereby cause the activation of automatic knotter 34 and cause a switch-over to currently inactive yarn element 18 upon the detection of a significant change in tension in yarn element 20. When such a tension change is detected, knotter 34 is activated, and a knot such as 19 is tied between the forward end of element 20 and the previously held forward end of the inactive yarn element 18; the excess portions and loops are severed and another new yarn element has been established following a suitable switch-over.

This invention is, as mentioned previously, applicable to the tying of different types of knots by different automatic knotters. One other such knotter is the Automatic Fisherman's Knotter, offered by Asquith Electrics (Colne) Ltd. of Lancashire, England. The use of such a knotter and its adaptability to different types of feeds as used in conjunction with this invention are illustrated in FIGS. 2 and 3 hereof. In FIG. 2, a perspective view of yarn being fed from packages on opposed side creels to an automatic knotter which ties a fishermans knot, is shown. This type of knotter has separate grooves for the two yarn elements, one active and one inactive; accordingly, the yarn elements must be fed to the knotter from opposite directions, and after the knot therebetween is tied, the knotter must reposition itself at a 180 rotation in order to accommodate the different new orientations of the formerly active and inactive yarn elements. It is known in this industry that an automatic knotter tying a fishermans knot desirably ties a relatively thin knot and is accordingly usable for relatively thick yarns where bulky knots are not permissible. (In the case of a knotter tying a silk knot as described above in connection with FIGS. 1 and 4-7, such a device is generally used for finer yarns so that the bulk of the knot is not as significant in view of the fact that the yarns themselves are relatively thin.)

Referring specifically to FIGS. 2 and 3, yarn package 54 at the left of FIG. 2 is delivering active yarn element 58 to the manufacturing location or other end use point (not shown). The travel path of yarn element 58 includes tension-limiting guide 64, tension detector 72, and bifurcated guide 73A, which leads to automatic knotter 74. The knotter is provided with a left grooved plate 84 and right grooved plate 82, with active yarn element 58 passing through

grooves

84A and 82A on its way to the end use location as indicated by the arrow adjacent to yarn element 58 extending away from knotter 74. At the same time, inactive yarn element 60 is being provided to the other pair of grooves in knotter 74 from yarn package 53, over a comparable path including tension-limiting guide 62, tension detector and bifurcated guide 73B. From the latter guide, inactive yarn 60 passes over an additional tension-limiting guide B, which is presently inactive, but which will ultimately act as the holding guide for the severed end of the inactive yarn element. From guide 90B, yarn element 60 passes through grooves 828 and 84B and its free end 60, is held in tension-limiting guide 90A. This establishes the waiting" condition of inactive yarn element 60 while active yarn element 58 is being consumed in the manufacturing process.

Automatic knotter 74 is mounted on a vertical shaft 76, which is rotatable about its longitudinal axis. Such rotation is generated, for example, by suitable gearing which is coupled to gear wheel 78 having suitable teeth for mating with such gearing (not shown). In addition, automatic knotter 74 is capable of vertical reciprocation, specifically by permitting its supporting shaft 76 to be vertically movable within its underlying mounting (not shown). This permits knotter 74 to be disengaged from the yarn feeding system for replacement of yarn elements, inspection or the like.

As with the first embodiment of this invention discussed above, knotter 74 is energized by the detection of a change in tension in the active yarn element. Referring to FIG. 2, tension detector 72 includes vertical slot 72A in which rod 728 rides against a normal spring bias in the direction indicated by arrow 72C. A decrease in tension in yarn element 58 (yarn breaks or loosens) causes rod 72B to ride upward in the direction of arrow 72C; a tension increase forces rod 72B downward in slot 72A (arrow 72D). In both cases, an activating signal is then transmitted to knotter 74.

When tension detector 72 detects a reduction or increase in tension of active yarn element 58, knotter 74 is activated, and trigger 86 is pulled to commence the tying of a fisherman's knot. The tying of such a knot (in conventional fashion) proceeds and knotter 74 is then rotated about the longitudinal axis of its vertical shaft 76 (see rotational arrow in FIG. 2). Upon completion of the tying of knot 59 (FIG. 3), the rotation of knotter 74 has been completed, leading to the orientation of positions illustrated in FIG. 3. Thus, as shown in that drawing, formerly active yarn element 58 has now been severed and its trailing edge 58 is now being held by formerly idle tension-limiting guide 908. Under these conditions, guide 90A is idle and is not involved in the holding of inactive yarn element 58. The element 58 now passes through the

same grooves

82A and 84A (in the opposite direction) which it had previously traversed as in FIG. 2, but is now merely held by guide 908.

The active yarn element is now element 60, and it is provided through grooves 848 and 828 to the manufacturing location following the tying of knot 59. Such knot couples the formerly held end 60, of previously inactive yarn element 60 to the trailing edge of previously active yarn element 58 to provide a continuous yarn feed. With the relative positions of structure and yarn elements as shown in FIG. 3, the system is pre pared for a subsequent switch-over based upon the detection of any change in tension in yarn element 60 by detector 70. This will cause automatic knotter 74 to go through a severing, knot-tying and rotational cycle as described above, whereby the active and inactive yarn elements are tied together and resume the orientations illustrated in FIG. 2. Similarly, knotter 74 itself would reassume the position illustrated in FIG. 2. As previously noted, the changes in tension which would acti vate either of detectors 70 (FIG. 3 mode) or 72 (FIG. 2 mode) would be based on a reduction in tension such as would be caused by a break in a yarn element, or by an increase in tension such as would be caused by a stretching or snagging of a yarn element. In either event, knotter 74 would be activated and the active and inactive yarn elements would change functions, thereby permitting an operator to inspect the yarn feeding mechanism and to replace or repair a yarn package as the case may be.

It will therefore be appreciated that this invention has been described with respect to the feeding of yarn elements from buried tail end yarn packages (dyed or natural yarns) to any one of a variety of end use or fabric manufacturing locations, and that the invention is equally applicable to all such mechanisms. As previously noted, the invention may be applied to knitting machines, looms, warp-makers or winding machines, to name some. Certain variations in the mechanisms disclosed will also be apparent to those skilled in the art. For example,

tension detectors

30 and 32 in FIG. I, or

detectors

70 and 72 in FIGS. 2 and 3, are indicated as being positioned along the yarn feeding paths, and particularly between tension-limiting guides and the automatic knotter. However, in addition thereto, detection of yarn quantities could be performed at the yarn packages themselves, for example by a suitable feeler" which would determine when the yarn on a package is nearly consumed and trigger the knotter.

The use of automatic knotters is also only one way to couple a new yarn element to the trailing edge of the formerly active element. For example, the elements can be coupled together by fusing, gluing, adhesively attaching or ravelling."

In addition, while the specific structure and operation at the end use or manufacturing location has not been illustrated herein since it can be substantially conventional, it should be noted that this invention is capable of working with various types of storage feed devices which are utilized to supply yarn from yarn packages to the end use points on a temporary wind-up and storage basis, thereby avoiding other feeding and tension problems. Since it may be desirable to stop the feeding of yarn at the end use point itself, the feeding of yarn to the manufacturing location may continue even while a knot is being tied in accordance with this invention. This will often occur if the particular machine is operating at a very rapid rate, and while the machine itself will not be interrupted, the storage feed device can be, since it has a built-in supply of yarn already wound up on its own drum. The storage feed device can be stopped for an instant while the knot is being tied and thereafter reactivated at an accelerated rate to compensate for the amount of yarn not wound up during the brief cessation of operation. This is merely one way in which the present invention can be utilized in conjunction with prior art structures, as will be known to those skilled in the art. (The machine itself can also be stopped briefly by using this invention, after which the machine would automatically restart.)

In addition, the invention is also applicable for use with exposed tail end yarn packages, successive ones of which are tied together, in order to increase the efficiency of operation of machines using such yarn pack ages.

It is to be understood that the above described embodiments are merely illustrative of the application of the principles of this invention. Numerous variations may be devised by those skilled in the art without departing from the spirit or scope of the invention.

What is claimed is:

1. Apparatus for providing a continuous supply of yarn to an end use location comprising a plurality of yarn packages furnishing respective active and inactive yarn elements, means for guiding said yarn elements toward said end use location, means for monitoring the tension in said active yarn element between said guiding means and said end use location, and connecting means responsive to said monitoring means detecting a change in tension in said active yarn element for coupling said inactive yarn element to a segment of said active yarn element.

2. Apparatus in accordance with claim 1 wherein said yarn packages are of the buried tail end type.

3. Apparatus in accordance with claim 2 wherein said yarn on said yarn packages of the buried tail end type is uniformly dyed prior to being provided to said end use location.

4. Apparatus in accordance with claim 2 including storage means for holding the forward end of said inactive yarn element and wherein said active yarn element is furnished in a continuous segment to said end use location, said connecting means including means for joining said forward end of said inactive yarn element to said active element to establish a new active yarn element and for severing said originally active element rearward of the junction of said active and inactive yarn elements to establish a free trailing end of said originally active element, whereby said trailing end is thereafter held by said storage means.

5. Apparatus in accordance with claim 2 wherein said connecting means comprises an automatic knotter for tying a knot between said active and inactive yarn elements and for severing said active yarn element rearward of said knot to define a new active yarn element consisting of a forward segment of said formerly active yarn element and a trailing segment of said formerly inactive yarn element.

6. Apparatus in accordance with claim wherein said automatic knotter includes a pair of parallel plates each having a groove for carrying said active and inactive yarn elements, and a trigger operative in response to a signal from said monitoring means to activate said knotter. and wherein said knot is of the silk knot type.

7. Apparatus in accordance with claim 5 wherein said automatic knotter includes a pair of parallel plates each having respective first and second grooves for carrying said active and inactive yarn elements, said active yarn element passing to said end use location through said first groove on each of said plates, first storage means for holding said trailing segment of said inactive yarn element, said inactive yarn element passing to said first storage means through said second grooves on each of said plates, second storage means for holding the severed trailing end of said active yarn element, and control means for rotating said knotter subsequent to the tying of said knot to position said knotter for carrying said formerly active yarn element to said second storage means through each of said grooves and for carrying said new active yarn element to said end use location through each of said second grooves, and wherein said knot is of the fishermans type.

8. Apparatus in accordance with claim 2 including a creel for mounting said yarn packages thereon, and wherein a first yarn package on said creel provides said active yarn element and a second yarn package on said creel provides said inactive yarn element.

9. Apparatus in accordance with claim 8 including a third yarn package on said creel for replacement of one of said first and second yarn packages.

10. Apparatus in accordance with claim 2 wherein said monitoring means includes a monitoring surface, a slot in said surface, a rod biased for movement in a first direction in said slot, and a rigid post on said surface for guiding said active yarn element toward said connecting means. said active yarn element passing from said guiding means and around opposite sides of said rod and said rigid post to establish a tension monitoring system. including means within said slot responsive to the movement of said rod in said first direction for activating said connecting means when said active yarn element exhibits a reduction in tension and responsive to the movement of said rod in a second direction, opposite to said first direction. for activating said connecting means when said active yarn element exhibits an increase in tension.

11. A method for supplying yarn without interruption from plural yarn packages to an end use location comprising the steps of mounting at least two of said yarn packages for feeding of yarn elements therefrom, one of said yarn elements being active and the other inactive, guiding each of said active and inactive yarn elements from said yarn packages toward said end use location, monitoring the tension in at least said active yarn element, temporarily holding the end of said inactive yarn element in position for connection to said active yarn element, and coupling said active yarn element to said temporarily held end of said inactive yarn element in response to an increase or decrease in said tension of said active yarn element to establish a new active yarn element fed from said yarn package corresponding to said formerly inactive yarn element.

12. A method in accordance with claim 11 including in addition the step of temporarily holding the end of said formerly active yarn element after said new active yarn element has been established in said coupling step.

13. A method in accordance with claim 12 wherein said yarn packages are of the buried tail end type.

14. A method in accordance with claim 13 wherein said coupling step includes the step of knotting a for ward end of said active yarn element to said temporarily held end of said inactive yarn element and severing said active yarn element behind the knot created during said knotting step.

15. A method in accordance with claim 14 wherein said knotting step includes the step of tying a silk knot.

16. A method in accordance with claim 14 wherein said knotting step includes the step of tying a fishermans knot.

Claims

6. Apparatus in accordance with claim 5 wherein said automatic knotter includes a pair of parallel plates each having a groove for carrying said active and inactive yarn elements, and a trigger operative in response to a signal from said monitoring means to activate said knotter, and wherein said knot is of the silk knot type.

7. Apparatus in accordance with claim 5 wherein said automatic knotter includes a pair of parallel plates each having respective first and second grooves for carrying said active and inactive yarn elements, said active yarn element passing to said end use location through said first groove on each of said plates, first storage means for holding said trailing segment of said inactive yarn element, said inactive yarn element passing to said first storage means through said second grooves on each of said plates, second storage means for holding the severed trailing end of said active yarn element, and control means for rotating said knotter subsequent to the tying of said knot to position said knotter for carrying said formerly active yarn element to said second storage means through each of said grooves and for carrying said new active yarn element to said end use location through each of said second grooves, and wherein said knot is of the fisherman''s type.

10. Apparatus in accordance with claim 2 wherein said monitoring means includes a monitoring surface, a slot in said surface, a rod biased for movement in a first direction in said slot, and a rigid post on said surface for guiding said active yarn element toward said connecting means, said active yarn element passing from said guiding means and around opposite sides of said rod and said rigid post to establish a tension monitoring system, including means within said slot responsive to the movement of said rod in said first direction for activating said connecting means when said active yarn element exhibits a reduction in tension and responsive to the movement of said rod in a second direction, opposite to said first direction, for activating said connecting means when said active yarn element exhibits an increase in tension.

14. A method in accordance with claim 13 wherein said coupling step includes the step of knotting a forward end of said active yarn element to said temporarily held end of said inactive yarn element and severing said active yarn element behind the knot created during said knotting step.

16. A method in accordance with claim 14 wherein said knotting step includes the step of tying a fisherman''s knot.