BE1017889A3 - WIRE TENSION CONTROL. - Google Patents

Abstract

Thread tension control mechanism (22) for use with thread (30) arranged to be unwound from yarn carriers and pulled into a yarn processing machine. The mechanism includes a wire guide (24) defining a plurality of passage (26) of the wire guide. Each passage (26) of the wire guide includes a wire entry end (28) in which wire (30) from a wire support is directed and a wire exit end (32) from which the yarn (30) is pulled into a yarn processing machine. An extraction mechanism is provided to unwind wire lengths (30) from the wire holders before the wire (30) is pulled into the wire processing machine so that the tension in the wire lengths (30) upstream thread entrance ends (28) of the thread guide passages (26) are minimized. An adjustable clamping member (36) is provided in each passage (26) of the wire guide between the wire entry end (28) and the wire exit end (32) to create an adjustable tension in the wire guide. wire (30) downstream of the clamping member (36) when the wire is pulled into the wire processing machine.

Description

FIELD OF THE INVENTION The invention relates to a thread tension control mechanism for use with yarn arranged to be unwound from yarn carriers and pulled into a yarn processing machine, and a method for controlling tension. of wire unwound from wire holders and pulled into a wire processing machine.

In textile processing, the yarn is generally stored in yarn carriers from which it is unwound and pulled, as needed, into a yarn processing machine. Such yarn processing machines include, for example, Axminster weaving looms where the yarn is typically stored in wire supports in the form of coils (cheeses) on a creel frame 12 as illustrated in FIG. 1. In such arrangements, wire is unwound from coils 10 through tubes 14 to wireboard 16 and then intermittently pulled into relatively short lengths of wire plate 16 in a loom 18.

Typically, the creel frame 12 comprises a large number of static pins 20 arranged in rows on which coils 10 are mounted so as to be rotatable.

During weaving, thread on a given spool 10 is unwound from one side of the spool 10 causing the spool 10 to rotate about an axis of rotation defined by the spindle 20 on which it is carried.

When a spool 10 is filled with yarn, the mass of yarn thereon is high. Therefore, the frictional resistance force between the spool 10 and the spindle 20 on which it is carried is also relatively high. This means that the resulting voltage in the unwound wire of the coil 10, i.e., the so-called "unwinding voltage" is also relatively high.

The spools 10 generally rotate freely on the spindles 20. As a result, the unwinding tension in the unwinding thread of a given spool 10 decreases as the diameter and weight of the spool 10 decreases.

In addition, yarns are typically reeled from different bobbins at different rates because of the color variations required in the weaving process. Therefore, the diameters of the different coils 10 change at different rates from each other so that the rate of change of the unwinding voltage Varies from one coil 10 to the other.

These variations are accentuated by elbows in the path of the son defined by the tubes 14 located between the creel frame 12 and the sonboard board 16.

Although these variations of the unwinding tension have been described with specific reference to the use of bobbins 10 on a creel frame 12 for use with an Axminster carpet weaving machine, these unwind tension variations will occur with other wire support forms.

According to one aspect of the invention, there is provided a yarn tension control mechanism for use with yarns arranged to be unwound from yarn carriers and pulled into a yarn processing machine, the mechanism comprising: a yarn guide defining a plurality of wire guide passages, each passage of the wire guide comprising a wire entry end into which wire from a wire carrier is directed and a wire exit end from which the wire is pulled into a wire processing machine, an extraction mechanism for extracting lengths of wire from the wire supports before the wire is pulled into the wire processing machine such that the tension in the wire lengths in upstream of the wire inlet ends of the wire guide passages is minimized, and an adjustable clamping member provided in each passage of the wire guide between the wire inlet end and the end of the wire guide. thread to create a predetermined amount of tension in the yarn downstream of the clamping member when pulled into the yarn processing machine.

Providing an extraction mechanism is advantageous because it allows any tension created in the wire due to the nature of the original wire supports and / or the path of the wire followed between the wire supports. and the extraction mechanism to be minimized.

Providing adjustable clamping members in the passageways of the wire guide allows a predetermined amount of tension to be created in the wire before it is pulled into a wire processing machine such as a wire loom. weave Axminster carpets, for example. It thus enables yarn to be pulled in a yarn processing machine to be stretched to an extent that will optimize the performance of the yarn processing machine, this energizing being essentially isolated from any tension created due to the size, weight and relative positions of the wire holders.

According to another aspect of the invention, there is provided a method of controlling the tension of the yarn to be unwound from yarn carriers in a yarn processing machine comprising the steps of: (i) feeding off lengths of media yarns of yarn before the yarn is pulled into a yarn processing machine so that the tension in the yarn lengths is minimized, and (ii) apply an adjustable clamping force to the yarn downstream of the yarn lengths and upstream of the yarn processing machine such that a predetermined amount of tension is created in the yarn when pulled into the yarn processing machine.

Embodiments of the invention will now be described, by way of non-limiting examples, with reference to the accompanying drawings in which: FIG. 1 illustrates the typical supply of yarn to an Axminster carpet loom, FIGS. 3 show a thread tension control mechanism according to one embodiment of the invention, FIG. 4 shows a cross-sectional view along the line V-V in FIGS. 2 and 3, FIG. in cross-section along line X-X in FIGS. 2 and 3, FIG. 6 shows a cross-sectional view of an extractor of a thread tension control mechanism according to another embodiment of FIG. 7 and 8 show a thread tension control mechanism according to a further embodiment of the invention, FIGS. 9 and 10 show a yarn tension control mechanism according to another embodiment of the invention. and FIGS. 11 and 12 show a thread tension control mechanism according to yet a further embodiment of the invention.

A thread tension control mechanism 22 according to one embodiment of the invention is shown in Figures 2 and 3 and includes a thread guide 24 defining a plurality of thread guide passages 26.

Each of the passageways 26 of the wire guide includes a wire entry end 28 in which wire 30 of a given wire support (not shown) is directed and a wire exit end 32 from which the wire 30 is directed to a wire processing machine (not shown).

The thread tension control mechanism 22 also includes an extraction mechanism in the form of an extractor 34 located upstream of the thread entrance ends 28 of the passageways 26 of the thread guide, and an adjustable clamping member 36 in each passage 26 of the wire guide between the wire entry end 28 and the wire exit end 32.

In the embodiment shown in Figs. 2 and 3, the extractor 34 comprises an extractor plate 38 in which elongated wire receiving openings 40 are formed as shown in Fig. 5.

The extractor plate 38 is laterally movably mounted relative to the wire entry ends 28 of the wire guide passages 26 between a rest position in which the elongated wire receiving openings 40 are aligned with the wire inlet ends 28 of the wire guide passages 26 (FIG. 2) and an extraction position in which the wire receiving openings 40 are offset from the wire entry ends 28 of the guide passages 26 -file (Figure 3).

Each of the clamping members 36 includes an inflatable bladder member 42 mounted on an inner surface of a side wall 44 of the respective passageway 26 of the wire guide so as to lie flat against the sidewall 44 in its deflated configuration and to extend to the opposite side wall 46 of the respective passage 26 of the wire guide in its inflated configuration.

Preferably, each bladder member 42 may be selectively inflated to control the extent to which it extends to the opposite sidewall 46 of the respective passageway 26 of the wire guide in its inflated configuration.

Preferably, a vacuum may be induced in each bladder member 42 to ensure that it lies flat against the sidewall 44 in its deflated configuration.

In the embodiment shown in Figures 2 and 3, each of the clamp members 36 includes a wear band 48 provided on the bladder member 42 such that the wear band 48 and the inner surface of the wall opposite side 46 define opposing clamping surfaces when the bladder member 42 is in its inflated configuration.

In other embodiments, the wear strips 48 may be omitted and the bladder members 42 themselves may each define a clamping surface.

The wires 30 are directed from the wire supports along the tubes 50 and through respective apertures 52 formed in the wire board 54, which correspond in position to the tubes 50, as shown in FIG. 4.

Preferably, the elongated wire receiving openings 40 formed in the puller plate 38 of the thread tension control mechanism 22 correspond in position to the openings 52 formed in the yarn board 54 so that the threads 30 can be directed from the wireboard 54 to the corresponding wire-receiving openings 40 in the extractor plate 38.

From the extractor plate 38, each of the threads 30 is directed into the thread entrance end 28 of a respective passage 26 of the thread guide so as to pass through the passage 26 of the thread guide and extending from the wire exit end 32 of the passage 26 of the wire guide. Each of the wires 30 is then directed to a wire processing machine.

During the insertion of the threads 30 into the respective passages 26 of the thread guide, the bladder member 42 of each of the bladder members 36 is held in its deflated configuration so as not to impede the movement of the threads 30 in the passageways 26 of the bladder member 36. guidewire.

Preferably, air blown down into the tubes 50 contributes to the insertion of the wires 30 into the wire entry ends 28 of the passageways 26 of the wire guide.

As soon as the threads 30 are located inside the passageways 26 of the thread guide, the bladder member 42 of each of the clamp members 36 is inflated to move the clamping surface defined by either the bladder member 42 or the wear band 48, if present, to the inner surface of the opposite side wall 46 of the respective passage 26 of the wire guide to clamp the respective wire 30 therebetween.

The clamping force provided by the clamping surfaces is determined by the extent to which each bladder member 42 is inflated.

In use, moving the extractor plate 38 from its rest position to its extraction position causes the edges of the elongate wire receiving openings 40 formed in the extractor plate 38 to contact the wires 30. passing through them. This causes wire lengths to be unwound from the respective wire holders to create wire loops 56 (FIG. 3) upstream of the wire entry ends 28 of the wire guide passages 26.

The clamping force provided by the clamping surfaces in each of the thread guide passageways 26 is selected to ensure that the movement of the extractor plate 38 from its rest position to its extraction position causes wire 30 to be unwound from the wire supports. Otherwise such a displacement of the extractor plate 38 will cause the wires 30 to be drawn from the passageways 26 of the wire guide. In this regard, it is preferable that the clamping force creates a tension in the wires 30 downstream of the wire guide passages 26 which is greater than the voltage in the wires 30 extending from the wire supports.

As soon as the loops 56 are formed upstream of the wire inlet ends 28 of the passages 26 of the wire guide, the extractor plate 38 is returned to its rest position. In this position, the tension in the yarns 30 immediately upstream of the yarn inlet ends 28 of the yarn guide passages 26 is minimized so that it is effectively zero. Therefore, when the yarn-processing machine pulls threads 26 from the yarn guide 26, the tension in the yarns 30 is determined solely by the clamping force provided by the clamping members 36 located in the guide passages 26 -fil.

In this way, the clamping force can be chosen so that the tension created in the threads 30 extending from the thread exit ends 32 of the thread guide passages 26, when the threads 30 are drawn into the processing machine. wire, optimizes the performance of the wire processing machine. It is also possible to ensure that, as much as possible, the same amount of tension is created in each of the threads 30 when the threads 30 are drawn into the thread processing machine.

The extractor plate 38 may be driven by a pneumatic cylinder, an electric motor, a mechanical linkage of the wire-processing machine, or other means whose movement is synchronized with the wire-processing machine so that the loops 56 yarns 30 are formed when the yarn-processing machine is not pulling the threads 30 from the thread guide passages 26.

In other embodiments, the extraction mechanism may include an extractor 34 in the form of a wire mesh 58 defining a series of wire receiving openings 60 between the wires 62, as shown in FIG. figure 6.

In such an arrangement, the wires 30 are directed through the wire receiving openings 60 in a manner similar to that described with reference to the wire receiving openings 40 formed in the extractor plate 38 shown in FIG. 3 and 5.

Similarly, the wire mesh 58 is movably mounted between a rest position and an extraction position in a manner similar to that described with reference to the extractor plate 38 shown in FIGS. 2, 3 and 5.

In still other embodiments, the wire guide 24 may itself define the extraction mechanism, thereby making the extractor 34 superfluous.

In such an embodiment, the wire guide 24 may be mounted laterally movable with respect to the wire board 54 between a rest position in which the wire inlet ends 28 of the guide passages 26 are aligned with the respective apertures 52 in the wireboard 54 (FIG. 7) and an extraction position in which the wire entry ends 28 are offset relative to the respective apertures 52 in the wireboard 54 (FIG. Figure 8).

In yet another embodiment, the wire guide 24 may be mounted so that it can be moved longitudinally with respect to the wireboard 54 between a rest position in which the wire entry ends 28 of the passageways 26 of the wire guide are aligned with a spacing of a predetermined distance x on the respective apertures 42 in the wireboard 54 (Fig. 9) and an extraction position in which the wire inlet ends 28 remain aligned but are spaced apart a predetermined distance x + y respective openings 52 in the sonboard 54 (Figure 10).

As with the puller 34 described earlier with reference to FIGS. 2 to 6, the lateral or longitudinal displacement of the wire guide 24 in these embodiments, in use, causes wire lengths to be unwound from the respective wire holders. to create wire loops upstream of the wire inlet ends 28 of the passageways 26 of the wire guide.

In these embodiments, if the wire guide 24 is mounted to be laterally or longitudinally movable with respect to the wire board 54, the wire guide 24 may be driven by a pneumatic cylinder, an electric motor or a motor. mechanical linkage of the wire processing machine or other means whose movement is synchronized with the wire processing machine so that the loops of the wires 30 are formed when the wire processing machine is not pulling the threads 30 of the passages 26 of the thread guide.

As indicated earlier, the clamping force provided by the clamping surfaces is chosen to ensure that the displacement of an extractor 34 in the form of an extractor plate 38 or wire mesh grid 58, or the displacement of the wire guide 24, causes the wire 30 to be unwound from the wire supports.

In this regard, the air pressure in the bladder member 42 of each of the clamping members 36 can be increased during the movement of the extractor 34 or wire guide 24 to increase the clamping force provided in each limb. clamping 36 and thus ensure that the wire 30 is unwound from the wire supports and is not drawn from the passages 26 of the wire guide.

The air pressure in the bladder member 42 of each of the clamping members 36 can then be decreased, if necessary, when the wire processing machine pulls the wire 30 from the wire guide passages 26 so that the clamp members 36 provide the tension in the threads required by the thread processing machine.

Such variations in the air pressure in the bladder member of each of the clamping members 36 are particularly preferable if the wire guide 24 can be moved longitudinally with respect to the wire board 54 to unwind the wire from the wire. thread. In these embodiments, there is less contact between the wire 30 and other components such as an extractor plate 34, a wire mesh 58 and / or a wire guide 24 at the inlet ends of the wire. The frictional engagement between the wire 30 downstream of the wireboard 54 is thereby minimized to the point that a greater clamping force may be required to ensure that the wire 30 is not drawn from the wires. passages 26 of the thread guide.

In still other embodiments, the inflatable bladders 42 of each of the clamp members 36 may be replaced by flexible tension bands 64, as shown in FIGS. 11 and 12.

In these embodiments, each flexible tension band 64 may be mounted on a movable bar 66 so as to extend from a side wall 44 of the passage 26 of the wire guide to the opposite side wall 46. In such arrangements the protruding end 68 of the flexible tension band 64 defines a clamping surface which is brought into contact with a wire 30 located in the respective passage 26 of the wire guide when the bar 66 moves towards the opposite side wall 46, as shown in Figure 12.

It is contemplated that in these arrangements, the magnitude of the clamping force provided by the tension bands 64 is determined by the extent to which the movable bars 66 are displaced to the opposite side walls 46 of the passageways 26 of the thread guide.

The clamping force is eliminated by moving the movable bars 66 away from the opposite side walls 46 of the passageways 26 of the thread guide, as shown in FIG. 11.

Although the embodiment shown in FIGS. 11 and 12 includes an extraction mechanism in the form of an extractor 34 comprising an extractor plate 38, it is envisaged that the flexible tension strips 64 may be used in embodiments where the wire guide 24 defines an extraction mechanism and is mounted to be movable relative to the wire board 54.

Claims (17)

A tension control mechanism for use with yarn arranged to be unwound from yarn carriers and pulled into a yarn processing machine, the mechanism comprising: a yarn guide defining a plurality of yarn guide passages, each yarn the wire guide comprising a wire entry end in which wire from a wire support is directed and a wire exit end from which the wire is drawn into a wire processing machine, a mechanism extraction device for extracting wire lengths from the wire supports before the wire is pulled into the wire processing machine such that the voltage in the wire lengths upstream of the wire entry ends of the guide passages -fil is minimized, and an adjustable clamping member provided in each passage of the wire guide between the wire inlet end and the wire outlet end to create a predetermined amount of voltage in the wire downstream of the clamping member when the wire is pulled into the wire processing machine. A voltage control mechanism according to claim 1, wherein the extraction mechanism is in the form of an extractor comprising an extractor member defining receiving openings through which wire from the wire supports extends before being directed into the wire entry ends of the respective passages of the wire guide, the extractor member being laterally movable with respect to the wire inlet ends for feeding wire lengths from the wire carriers. The tension control mechanism of claim 2, wherein the extractor member is in the form of an extractor plate defining a series of elongate yarn receiving openings. The voltage control mechanism of claim 2, wherein the extractor member is in the form of a wire mesh defining a series of wire receiving openings between the wire wires of the gate. A tension control mechanism according to any one of claims 2-4, wherein the extractor member is driven to move between a rest position where the wire receiving openings are aligned at the entrance ends wire lead passageways and an extraction position where the wire receiving openings are offset from the wire entry ends of the wire guide passages. The tension control mechanism according to claim 5, wherein the displacement of the extractor member can be controlled to be synchronized with the yarn processing machine so that yarn lengths are formed when the yarn processing machine does not pull wire from the wire exit ends of the wire guide passages. The tension control mechanism of claim 1, wherein the yarn guide defines the extraction mechanism, the yarn guide being laterally movable relative to the yarn carriers for feeding wire lengths from the yarn carriers. The tension control mechanism of claim 1, wherein the yarn guide defines the extraction mechanism, the yarn guide being longitudinally movable relative to the yarn carriers for feeding wire lengths from the yarn carriers. The tension control mechanism of claim 7 or claim 8, wherein the movement of the yarn guide can be controlled to be synchronized with the yarn processing machine so that yarn lengths are formed when the processing machine. wire does not pull wire from the wire exit ends of the wire guide passages. A tension control mechanism as claimed in any one of the preceding claims, wherein each clamping member comprises an inflatable bladder member mounted on an inner surface of a side wall of the respective passage of the thread guide, each bladder member. selectively inflatable to extend to the opposite side wall of the respective passage of the wire guide. The tension control mechanism of claim 10, wherein the degree of inflation of each bladder member can be controlled to control the clamping force provided upon inflation of the bladder member between opposed clamping surfaces defined on the bladder member and the opposite side wall of the respective passage of the wire guide. The tension control mechanism of claim 10 or claim 11, wherein a wear band is provided on each bladder member to define a clamping surface on the bladder member. The tension control mechanism according to any one of claims 1-9, wherein each clamping member comprises a flexible tension band extending from a side wall of the respective passage of the thread guide to the opposite wall of the respective passage of the guide wire. The tension control mechanism according to claim 13, wherein the flexible tension band is mounted on a bar movable so as to be movable relative to the opposite side wall of the respective passage of the wire guide to adjust the clamping force provided between the clamping surfaces provided on the end of the tension band and the opposite side wall of the respective passage of the thread guide. A method of controlling the tension of the yarn to be unwound from yarn carriers and pulled into a yarn processing machine, comprising the steps of: (i) feeding yarn lengths of yarn carriers before the yarn is pulled in a yarn processing machine such that the tension in the lengths of yarn is minimized, and (ii) applying an adjustable clamping force to the yarn downstream of the yarn lengths and upstream of the yarn processing machine such that a predetermined amount of tension is created in the yarn when pulled into the yarn processing machine. 16. Thread tension control mechanism generally as described herein with reference to Figures 2 - 12 and / or illustrated in Figures 2-12 of the accompanying drawings. A yarn tension control method for unwinding wire supports and pulling in a yarn processing machine generally as described herein with reference to FIGS. 2-12 and / or illustrated in FIGS. 2-12. attached drawings.