Strand Storing and Delivering Device

The present invention relates generally to devices for feeding a traveling strand or the like to a textile or like machine and more particularly relates to such devices of the type including a rotable storage drum or spool adapted to receive several strand windings circumferentially thereabout for transient storage and delivery of a traveling strand by winding and unwinding thereof onto and off the drum or spool.

As used herein, the term "strand" is intended to generically define and indicate any continuous length material such as yarn, thread, filament, wire, rope, cable, tape or the like.

A relatively wide variety of drum or spool devices of the above-described type are well known in the textile industry and are commonly referred to as "storage feeding devices." Representative examples of such storage feeding devices are disclosed in U.S. Pat. Nos. 3,606,975; 3,642,219; 3,648,939; 3,747,864; 3,796,384; 3,827,645; 3,908,921; 3,928,987; 3,952,554; 4,106,713; 4,138,866; 4,457,144; and 4,481,794. In basic construction, conventional storage feeding devices of the type of the above-listed patents essentially include a strand storage drum or spool for winding thereabout and unwinding therefrom the traveling strand to be stored and fed, with some arrangement being provided to cause the strand windings to move progressively axially on the drum from the on-winding location to the off-winding location. A pulley or similar driving member is fixedly interconnected coaxially with the drum or spool for integral driven rotation by the associated textile or like machine for effecting the on and off winding of the strand in synchronism to the operation of the associated machine.

One of the important purposes served by such storage feeding devices is to continuously maintain transiently a small quantity of the traveling strand so that, in the event of a breakage in the strand between the strand supply and the textile machine, the breakage can be detected by suitable strand monitoring arrangements and the machine can accordingly be stopped before the broken trailing end of the strand is drawn into the textile machine and can no longer be spliced or otherwise rejoined to the leading broken end of the strand from the strand supply. In this regard, conventional storage feeding devices are typically provided with a strand monitoring arrangement, commonly referred to in the industry as a "stop motion," to detect breakages in the traveling strand. In many conventional storage feeding devices, such a stop motion is arranged to monitor the strand upstream drum and often a second stop motion is provided to monitor the traveling strand downstream of the storage drum as well.

While such stop motions serve the intended purpose of detecting strand breakages and actuating stoppage of the textile machine, it is common for such stop motions to also deactuate the textile machine for no apparent reason when no breakage of the traveling strand has occurred, commonly called "false stops." While it is not fully known and understood why such false stops occur and some disagreement in the industry exists in this regard, it is believed that natural tension fluctuations and flutterings in the traveling strand between the strand supply and the storage feeding device sometimes permit sufficient movement of the upstream stop motion arrangement to cause deactuation of the associated textile machine.

A number of conventional storage feeding devices are provided with spring-biased tension disks or similar strand braking devices through which the traveling strand is trained upstream of the storage feeding device and its stop motions. The above-listed U.S. Pat. Nos. 3,908,921; 3,928,987; 3,952,554; and 4,106,713 disclose representative uses of such tension disk-type braking devices in conventional storage feeding devices. It is believed that such braking devices are utilized essentially only for the purpose of tensioning the strand in the area of the upstream stop motion in order to prevent false stops.

While such braking arrangements to at least some extent aid in reducing the occurrence of false stops, these braking arrangements create additional more serious problems. Ordinarily, the natural tension existing in a traveling textile strand provides as much tension as is necessary for most textile operations. Accordingly, it is considered undesirable to impose additional tension on a traveling textile strand beyond the minimum amount necessary. Tension disks such as those disclosed in the aforementioned patents and other similar braking arrangements create additional strand tension through the imposition of friction thereon, which may deleriously cause fraying and lint accumulation when used on spun strands and similar fibrous textile strands, as well as occasional strand breakages when the strand tension level becomes too great. Lint production and accumulation only worsen existing environmental problems in many textile mills and furthermore cause quality control problems by increasing the occurrence of strand slubs. At best, the lint accumulation on the braking devices must be periodically removed, sometimes requiring stopping of the associated textile machine with an attendant reduction in the machine production and efficiency.

In contrast, the present invention provides an improved storage feeding device which substantially eliminates the occurrence of false stops of the associated textile machine without the use of any strand braking device or otherwise imposing additional tension on the traveling strand.

The present storage feeding device is basically adapted for transiently storing and delivering a traveling strand to a textile machine, e.g., a circular knitting machine, or the like. Briefly summarized, the present storage feeding device includes rotatable first and second circumferential portions about and from each of which the traveling strand may be wound and unwound and a driving arrangement for rotating the first and second circumferential portions synchronously. A guiding arrangement directs the strand to travel in sequence a plurality of windings about the first circumferential portion and a plurality of windings about the second circumferential portion, with a stop motion being provided for monitoring the strand intermediate the first and second circumferential portions for detecting breakages in the strand. In this manner, the stop motion is isolated from tension variations in the strand upstream of the first circumferential portion to detect only actual breakages of said strand without applying any significant increase in tension in the strand.

Preferably, the strand storage arrangement includes first and second strand storage drums the respective peripheries of which form the circumferential portions, the strand storage drums being integrally affixed in spaced coaxial relation with one another for synchronous rotation. The driving arrangement preferably is a pulley assembly mounted coaxially with the strand storage drums. The guiding arrangement is adapted for feeding the strand generally tangentially to and withdrawing the strand generally tangentially from the circumferential portion of each drum. The stop motion includes a pivotable arm arranged to rest gravitationally on the traveling length of the strand intermediate the first and second storage drums and to fall gravitationally in response to tension loss in the traveling strand length. Another stop motion is preferably provided for monitoring the strand downstream of the second strand storage drum for detecting breakages in the strand intermediate the storage feeding device and the textile machine.

A cap member is rotatably mounted coaxially with and adjacently upstream of the first strand storage drum and an arm extends outwardly from the cap member with an eyelet arrangement on the arm for receiving the strand, the arm being operative to windingly wrap the strand about the circumferential portion of the first strand storage drum upon rotation of the cap member to facilitate thread-up of the storage feeding device.

The accompanying drawing is a side view of the preferred embodiment of the strand storage device of the present invention partially in side elevation and partially in axial section.

Referring now to the accompanying drawing, the storage feeding device of the present invention is generally indicated at 10. The storage feeding device 10 basically includes a support assembly 12 on which a strand storage assembly 14 and a pulley assembly 16 are rotatably mounted for unitary rotation. An arrangement of strand guides, indicated generally at 18, are also mounted on the support assembly 16 to define a strand travel path through the device 10 and a stop motion arrangement, indicated generally at 20, is provided for monitoring the strand to detect breakages.

The support assembly 12 includes a longitudinal mounting block 22 having a downwardly open channel 24 formed in the rearward end thereof and adapted to receive an appropriate support member 26 such as a circular support rail or ring typically forming part of the strand feeding and guiding arrangement of a conventional circular knitting machine. A threaded opening 28 is formed through the mounting block 22 to open into the channel 24 and receives an Allen screw 30 for selective clamping of the mounting block 22 horizontally on and unclamping from the support member 26.

The pulley assembly 16 is of the conventional type having a pair of circular pulley wheels 32, each having a plurality of axial teeth 34 formed at spacings in the circumferential periphery thereof to meshingly engage with a toothed drive belt or tape 36 which is employed in a known manner in the strand feeding arrangement of the circular knitting machine. The two pulley wheels 32 are rotatably mounted coaxially adjacent one another on a central support shaft assembly 38 by respective bearing assemblies 40. A clutch disk assembly 42 is rigidly affixed to the support shaft assembly 38 intermediate and coaxially with the pulley wheels 32 and is arranged for axial movement between the two pulley wheels 32 into and out of selective frictional engagement of one or the other thereof to fix the selected pulley wheel 32 in driving relation with the supporting shaft assembly 38. As is conventional, the pulley wheels 32 are of differing diameters to permit selective driving of the supporting shaft assembly 38 at differing speeds. The supporting shaft assembly 38 extends oppositely beyond each pulley wheel 32, with the lower end of the shaft assembly 38 being rotatably mounted in the mounting block 22 by a bearing assembly 44 fitted in the mounting block 22 to position the shaft assembly 38 in an upright disposition with the pulley assembly 16 directly above the mounting block 22.

The strand storage assembly 14 basically includes a pair of storage drums 46 one of which is rigidly fixed to the projecting lower end of the supporting shaft assembly 38 immediately beneath the mounting block 22 and the other of which is rigidly affixed to the projecting upper end of the supporting shaft assembly 38 immediately above the upper pulley wheel 32. In this manner, the two storage drums 46 are arranged for integral synchronous coaxial rotation with the active pulley wheel 32 which is drivingly connected with the shaft assembly 38 by the clutch disk 42. Each storage drum 46 has a circular periphery 48 of a generally concave shape in axial section to provide a circumferential strand storage portion about and from which a strand may be wound and unwound. The concave periphery 48 of each storage drum 46 is effective to cause strand windings applied thereto at the upper axial end thereof to be deflected axially downwardly along the periphery 48 as the storage drum 46 rotates, thereby to tend to maintain a single layer of strand windings about each drum 46, as hereinafter more fully explained.

The upper projecting end of the shaft assembly 38 includes a terminal stub portion extending upwardly beyond the upper storage drum 46 on which stub portion a bearing assembly 50 is rotatably mounted. A cap member 52 is frictionally fitted on the bearing assembly 50 for rotational movement relative thereto and particularly relative to the upper storage drum 46 for purposes to be hereinafter more fully described and explained. A projecting arm 54 extends radially outwardly from the cap member 52 and has a guide eyelet 56 fitted in an opening through the intermediate portion of the arm 54. An upright arm 58 is affixed in upstanding relation to the upper surface of the mounting block 22 at the end thereof opposite the mounting channel 24 and includes a bend 60 in the intermediate portion of the arm 58 through which another guide eyelet 62 is fitted. The upper free end of the upright arm 58 is provided with a slotted opening 64 adapted to receive and retain the extending free end of the radial arm 54 from the cap member 52. A pair of finger members 66 having hook portions 68 at their projecting ends are mounted side-by-side on the upper surface of the mounting block 22 at the same location as the upstanding arm 58 and project forwardly therefrom directly beneath the bend 60 in the arm 58 with the hook portions 68 of the finger members 66 overlapping one another, thereby defining a guide slit 70 between the finger members 66. The mounting block 22 includes a leg 72 projecting forwardly from the vertical face of the mounting block 22 at the end thereof opposite the channel 24, with a guide bar 74 of plorcelain, polished metal or other smooth surface extending perpendicularly and horizontally from the leg 72. A depending leg 76 projects downwardly from the underside of the mounting block 22 immediately forwardly of the lower storage drum 46 and has a guide eyelet 78 fitted therethrough generally at the level of the upper axial end of the circumferential periphery 48 of the lower drum 46. A pair of U-shaped guide legs 80 are affixed to the underside of the mounting block 22 in parallel aligned spaced relation to one another immediately rearwardly of the lower storage drum 46. While each of the guide eyelets 56,62,78 in the illustrated embodiment are of the conventional annular type, it will be understood that other types of guide eyelets may be employed and, particularly, it is contemplated that spiral or pigtail-type eyelets could be employed to facilitate the ease of the thread-up operation of the device 10 hereinafter more fully described.

The stop motion arrangement 20 includes a first U-shaped arm 82 pivotably mounted to the opposite sides of the mounting block 22 adjacent the upper surface thereof and extending downwardly and forwardly therefrom to dispose the transverse connecting portion 82' of the arm 82 for pivotal movement between an upward position in general alignment between the guide bar 74 and the eyelet 78, as shown in full lines, and a downward position below the level of the eyelet 78, as shown in broken lines. A second U-shaped stop motion arm 84 is similarly pivoted to opposite sides of the mounting block 22 at the upper surface thereof immediately adjacent the pivot location of the arm 82 and extends downwardly and rearwardly therefrom for pivotal movement of the connecting portion 84' of the arm 84 between an upward position intermediate the lower ends of the two U-shaped guide legs 80, as shown in full lines, and a downward position beneath the level of the U-shaped legs 80, as shown in broken lines. In conventional manner, each stop motion arm 82,84 is electrically connected at the location of its respective pivot mounting to an alarm device, which may be either a lightbulb, an audible alarm or the like, to activate the alarm when the respective stop motion arm 82,84 is in its respective lower position. The alarm device is electrically connected in turn to the associated textile machine to deactivate it when the alarm device is triggered by either of the stop motion arms 82,84. In the preferred embodiment, the forward end of the mounting block is formed of a hollow translucent or transparent plastic housing 86 in which a lightbulb of the alarm device is housed to provide a visual indication when the alarm device is activated.

In operation of the strand storage device 10 in a typical embodiment in association with a textile machine such as a circular knitting machine, the device 10 is mounted in a disposition intermediately of a strand supply, indicated only representatively at S, and the knitting or other textile machine, also indicated only representatively at T, and is oriented with its strand guide eyelet 56 positioned to receive the strand from the supply S in its path of travel to the textile machine T and with its U-shaped guide legs 80 positioned in line to direct the traveling strand to the textile machine T after leaving the device 10. As will be understood, a conventional multi-feed circular knitting machine will employ a respective strand supply for each knitting station whereby a respective plurality of the devices 10 will be employed. The strand A is directed through the guide eyelet 56; extends therefrom tangentially to and is wound several times circumferentially about the periphery 48 of the upper drum 46; is withdrawn tangentially therefrom forwardly and directed successively through the guide eyelet 62, through the slit 70 between the fingers 66, forwardly about the guide bar 74 and through the guide eyelet 78; extends therefrom tangentially to and is wound several times circumferentially about the periphery 48 of the lower drum 46; and is withdrawn tangentially from the lower drum 46 and directed successively through the two U-shaped guide legs 80.

As will be understood, the ongoing operation of the textile machine T creates an ongoing requirement for additional strand A and, for this purpose, the driving belt 36, which is driven from the textile machine T synchronously therewith in conventional manner, is trained about the periphery of the active one of the pulley wheels 32 selectively engaged by the clutch disk 42 and in proper meshing engagement with the teeth 34 of the selected active pulley wheel 32 of each device 10 being employed. Thus, the active pulley wheel 32 and the upper and lower storage drums 46 of each device 10 are unitarily rotated synchronously with the machine T, whereby the strand A is caused to travel longitudinally from the supply S to the textile machine T during which it is transiently stored in sequence wrappingly about the upper and lower storage drums 46. As the traveling strand A passes through the guide eyelet 56, it is tangentially placed initially onto the periphery 48 of the upper drum 46 adjacent the upper axial end thereof. As integral rotation of the active pulley wheel 32 progresses and in turn rotatably drives the upper storage drum 46, the strand A is wrapped about the upper portion of the periphery 48 of the upper drum 46, but due to the concave axial shape of the periphery 48 and due to the tension existing in the strand A, the strand A is deflected axially downwardly along the periphery 48 toward its central area of reduced diameter and is wrapped thereabout. The wrapping of the strand A thereafter naturally migrates progressively axially downwardly along the periphery 48 of the upper drum 46 under the pushing effect created by the deflection of the following length of the strand A. Similarly, the strand A, upon off-winding from the lower portion of the periphery 48 of the upper drum 46 and direction through the eyelet 62, the slit 70, the guide bar 74 and the eyelet 78, is wrapped about and deflected axially along the periphery 48 of the lower drum 46 in identical manner. This manner of strand wrapping deflection and migration occurs progressively as the strand A is continuously fed and wrapped about each drum 46 as the integral rotation of the active pulley wheel 32 and the storage drums 46 continues, thereby to produce a single layer of windings of the strand A about each storage drum 46.

In the initial thread-up of the strand A, each U-shaped stop motion arm 82,84 is pivoted upwardly to its respective upper position to dispose its respective connecting portion 82',84', restingly on the traveling strand A, with the connecting portion 82' resting gravitationally on the extent of the traveling strand A between the guide bar 74 and the eyelet 78 generally in line therewith and the connecting portion 84' resting gravitationally on the extent of the traveling strand A intermediate the two U-shaped guide legs 80 generally in line therewith. In this manner, the stop motion arms 82,84 are maintained pivoted out of their downward positions under the influence of normal strand tension to deactivate the associated alarm and stop motion mechanism and thereby to enable the operation of the machine T to progress normally. On the other hand, as will be understood, upon any significant loss in the tension of the strand A along the extents thereof supporting the stop motion arms 82,84, respectively, sufficient to permit one or the other, or both, of the arms 82,84 to pivot downwardly to its downward position, such as would occur normally in the event of a breakage in the strand A, the stop motion 82,84 so pivoting will activate the associated alarm and stop motion arrangement to immediately stop operation of the machine T. As will be understood, the stop motion arm 82 effectively monitors the traveling strand A to detect breakages or other significant tension losses therein upstream of the lower storage drum 46, while the stop motion arm 84 monitors the strand A to detect breakages or other significant strand tension losses downstream of the lower storage drum 46. In the event of an upstream strand breakage, e.g., between the strand supply S and the upper storage drum 46 along which extent experience shows most strand breakages occur, the stored quantity of the strand A about the upper storage drum 46 will initially deplete and travel to the lower storage drum 46, at which time the stop motion 82 will gravitationally pivot to its downward position by virtue of the resultant loss of strand tension to activate the alarm and stop motion arrangement and stop operation of the machine T before any significant depletion of the stored strand A from the lower drum 46 occurs. In the event of a downstream strand breakage, the stop motion arm 84 will almost immediately pivot gravitationally to its downward position to activate the alarm and stop motion arrangement and stop the textile machine T without any significant effect at all on the storage device 10.

Importantly, the provision in the present storage device 10 of both upper and lower storage drums 46 for sequential storage of the traveling strand A in conjunction with the stop motion arm 82 monitoring the strand extent intermediate the two drums 46, effectively isolates the stop motion arm 82 from any tension variations, flutterings or the like occurring along the traveling length of the strand A either upstream or downstream of the storage device 10. Furthermore, the path of traveling movement of the strand A from the upper storage drum 46 to the lower storage drum 46 is closely controlled and constrained by the guide members 62,66,74,78 so that no similar tension variation, flutterings or the like occur along this traveling extent of the strand A, but without imposing any significant increase in friction or tension on the strand A. Accordingly, the stop motion arm 82 will activate the associated alarm and stop motion arrangement essentially only upon actual breakages in the strand A upstream of the lower storage drum 46. As a result, so-called "false stops" of the machine T, occurring when a stop motion arrangement is activated without the occurrence of an actual strand breakage, are essentially entirely eliminated by the present storage device. Although the precise cause of false stops in conventional storage feeding devices has not been conclusively identified, it is believed that, in conventional storage feeding devices wherein an upper storage drum is not provided, the constant effect of strand tension variations and flutterings continuously produce corresponding fluttering of the upstream stop motion arrangement which occasionally are of sufficient magnitude to activate the stop motion arrangement to stop the machine T although no strand breakage has occurred. In the practical utilization of the present storage feeding device, it has been found that false stops are virtually non-existent and it is believed that this is the result of the arrangement of the two storage feeding drums 46 on opposite sides of the upstream stop motion arm 82 which effectively prevents the aforesaid fluttering and like unintended pivoted movements of the stop motion arm 82 without affecting normal strand tension.

According to another feature of the present invention, the rotable cap member 52 provides a convenient manner of winding the strand A about the upper storage drum 46 during the thread-up process so as to readily facilitate the rethreading of the strand A following an upstream strand breakage. As above-explained, in the event of an upstream strand breakage, the strand A will be depleted from the upper storage drum 46 before the upstream stop motion arm 82 can activate the associated alarm and stop motion arrangement. Accordingly, following each such upstream strand breakage, it is necessary in rethreading the strand A to rewind it about the upper storage drum 46. To accomplish this, the leading broken end of the strand A is threaded initially through the eyelet 56 and thereform directly through the eyelet 62 in the arm 58 and subsequently through the slit 70, about the guide bar 74 and through the eyelet 78, and is rejoined by a splicing or knotting operation to the broken end of the trailing length of the strand A wrapped about the lower storage drum 46. The radial arm 54 of the cap member 52 is then removed from rention in the opening 64 of the upstanding arm 58, which is sufficiently resilient to yield to release the arm 54, whereby the cap member 52 and the radial arm 54 may then be rotated as a unit relative to the shaft assembly 38 and to the upper strand storage drum 46. Accordingly, the cap member 52 is then manually rotated a sufficient number of revolutions about the shaft assembly 38, whereby the strand A is progressively drawn from the supply S through the eyelet 56 in the radial arm 54 and wound about the upper storage drum 46 while the downstream length of the strand A is essentially held by the lower storage drum 46 and the upstream guide members 62,66,74 and 78. Once a sufficient number of windings of the strand A have been wrapped about the upper storage drum 46, the projecting end of the radial arm 54 is again positioned in the opening 64 of the upstanding arm 58, whereby the storage device 10 is again ready for operation in the above-described manner. As will be understood, this winding operation of the cap member 52 and arm 54 greatly simplifies and reduces the required time for the necessary thread-up of the strand A following an upstream strand breakage and thereby greatly reduces machine down time occurring during any such strand breakage, as well as enabling the machine operator to monitor and tend to a greater number of traveling strands.

It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of a broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation it its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.