GB2185267A - Apparatus for producing two- component thread - Google Patents

Abstract

The apparatus for producing two-component thread comprises a twisting member (5) to which the two components of the two- component thread are fed, and a device for severing one of the components of the two-component thread when the feed of the other component ceases, including a hollow cylinder (10) operatively connected with a drive (14), the cylinder having an annular slit (11) made in its periphery, the inner space of the cylinder (10) accommodating at least one flat knife (22). The slit (11) has a width less than the two component thread but greater than a single component so that when one component is missing the thread moves through the slit to be severed by knife (22). <IMAGE>

Description

SPECIFICATION Apparatus for producing two-component thread The present invention relates to spinning processes in the textile industry, and more particuiarly it relates to apparatus for producing two-component thread, such as reinforced thread.

The invention can be employed in any machine in the textile industry, intended for the manufacture of two-component thread, e.g. in spinning-cum-reinforcing rotative machines or spinning-cum-twisting machines.

It is generally known that one of the problems encountered in the technology of production of two-component thread is that of preventing winding into the bobbin with the final thread either one of the components of the two-component thread in the absence of the other component.

This problem is solved, as a rule, by positively severing by cutting or breaking the remaining other component of the two-component thread when the feed of either one of the components ceases, for which purpose the presence of both components of the thread prior to their -twisting together is monitored with aid of various techniques and devices. Most of the latter are based on monitoring by direct contact, i.e. by checking each one of the two components of the thread with feelers of various kinds.

However, this monitoring technique can be employed only in case of two-component threads whose both components permit their physical checking in direct contact with the feelers used, i.e. whose both components have adequate relative strength and tension, e.g. in the production of twisted sewing thread.

Another existing technique is monitoring the thickness of the final thread after the twisting together of the components, a sudden drop of this thickness being considered representative of faulty operation and employed as a signal triggering the actuation of corresponding mechanisms. This technique is far more suitable in case of two-component thread where the wound-around component is a stream of loose separated fibres which would not be physically contacted by a feeler.

The simplest devices embodying this technique are of the go/no-go gauge kind. A device of this type includes an element with a slit, adapted to contact the thread, the width of this slit being greater than the thickness of a single thread, but short of the thickness of the final two-component thread. Should either one of the components become broken or exhausted, the other component drops into the slit, which is considered a signal of faulty operation.

Efficient and reliable performance of devices of this kind is dependent, however, on the ratio of the thickness of one of the components to that of the two-component thread being at least in the 1:5 to 1:10 range.

There are known various devices performing on this go/no-go gauge principle. Thus, there is known a device for breaking one of the components of a two-component thread in case of accidental breakage or exhaustion of the other component in a spinning-cum-twisting machine (cf. DD Patent No. 75,469; Int.

Cl. D 01 h; dated 1970), comprising an electric sensor with a feeler with a slit monitoring the thread, arranged in front of the winding mechanism at the horizontal portion of the path of the final thread. The sensor is associated with an electromagnet adapted to actuate through an appropriate linkage the devices for individually engaging and breaking either one of the components of the two-component thread.

This known device employs a complicated system of transmitting a signal warning of faulty operation from the sensor to the actuating members, and a complicated design of the breaking devices themselves. Furthermore, the considerably distance from the location of the sensor with the feeler to the point of positive breakage of the components leads to an increased amount of waste in the form of a single thread, and complicates the servicing when the consequences of a breakage are to be eliminated, as the remaining single component of the thread is wound into the bobbin and requires subsequent removal.

There is further known an apparatus for producing two-component thread (cf. SU Inventor's Certicificate No. 706,473; Int. Cl.2 D 01 H 13/16; dated 1979), comprising a twisting member, a holder of a package with a supply of one of the components of the twocomponent thread, means for feeding the other component of the two-component thread into the twisting member, a unit for winding the two-component thread including a holder of a package, having an axle for its rotation, and a device for breaking one component of the two-component thread upon ceasing of the feed of the other component of the two-component thread, arranged intermediate the twisting member and the winding unit and including an element with a slit, adapted to contact the two-component thread, the width of the slit being less than the thickness of the two-component thread and greater than the thickness of one component of the two-component thread.

In this apparatus the twisting member is in the form of the hollow spindle of a spinningcum-twisting machine, supporting a bobbin with the thread, and the device for breaking the remaining component of the two-component thread in the absence of the other component includes a slit-type thread guide underlying the spindle, a deflecting bar offset from the axis of the spindle, and a sleeve mounted on the lowermost part of the spindle, for winding and breaking the component of the final thread that has passed through the slittype guide in the absence of the other component.

In this apparatus the positive breakage of one of the components of the thread is performed by the sleeve of a simple design, as a result of an excessive tension of this component of the thread imparted by the winding unit, this breakage taking place practically exactly at the same spot where the fault is detected, so that defective thread would not be wound into the bobbin with the final thread, and no time is wasted on its removal by unwinding.

However, the winding of the component of the thread which has to be broken onto the sleeve revolving with the spindle involves some unwanted consequences. Firstly, this complicates the operating of the machine and impairs the productivity, as the bobbin has to be stopped to clean the sleeve from the wound component; secondly, when the component of the thread is relatively strong, e.g.

made of synthetic fibres, its tension directed away from the axis of the spindle applies excessive lateral loads to the bearings of the spindle, stepping up the wear of these bearings and curtailing their service life; and, finally, the component wound onto the sleeve goes to waste, which increases the input of the components of the thread and affects the yield of standard thread.

It is an object of the present invention to create an apparatus for producing two-component thread, which should provide for eliminating lateral loading of the bearings of the twisting member, so as to reduce their wear and prolong the service life of the apparatus.

It is also an other object of the present invention to provide for reducing the waste of the components of two-component thread, so as to save the initial materials.

With these and other objects in view, the present invention resides in an apparatus for producing two-component thread, comprising a twisting member, a holder of a bobbin with a supply of one component of the two-component thread, means for feeding the other component of the two-component thread into the twisting member, a unit for winding the two-component thread including a holder of a package, having an axle for its rotation, and a device for severing one of the components of the two-component thread upon ceasing of the feed of the other component of the twocomponent thread, arranged intermediate the twisting member and the winding unit and including an element with a slit, adapted to contact the two-component thread, the width of the slit being less than the thickness of the two-component thread and greater than the thickness of the one component of the twocomponent thread, in which apparatus, in accordance with the present invention, the element with the slit is in the form of a hollow cylinder operatively connected with a drive, the slit in the cylinder being annular, and the inner space of the hollow cylinder accommodating at least one flat knife with a blade adjoining the slit.

To shorten the time of transmitting a signal in response to affected integrity of the twocomponent thread to the means for feeding the other component of the two-component thread, so as to terminate the feeding of this component, it is expedient to have a sensor of breakage of the two-component thread arranged intermediate the twisting member and the winding unit, electrically connected with the means for feeding the other component and operatively connected through a linkage with the axle for rotation of the hollow cylinder.

To enhance the uniformity of delivery and winding of the two-component thread, it is advisable to have a delivery couple arranged intermediate the twisting member and the winding unit, including a delivery shaft and the hollow cylinder adapted to engage this shaft.

To simplify the structure of the apparatus, it is preferable to have the hollow cylinder arranged in the zone of winding of the twocomponent thread, forming a part of the winding unit.

To speed up the severing of the core thread and to avoid unbalanced rotation of the hollow cylinder, it is expedient that the inner space of the hollow cylinder should accommodate a plurality of flat knives arranged radially at uniform spacing in a plane perpendicular to the axis of the hollow cylinder.

The herein disclosed apparatus eliminates the necessity of winding the thread onto the twisting member for breaking the thread, which precludes lateral loading of the bearings of the twisting member, thus reducing their wear and prolonging the service life of the apparatus, and also cutting down the time of servicing the apparatus and the percentage of waste, saving the initial materials and stepping up the yield of standard two-component thread.

The present invention will be further described in connection with its embodiments in an apparatus for producing one kind of twocomponent thread, i.e. reinforced thread having for one its component a core thread and for its other component loose fibres wound or twisted around the core thread, the embodiments being illustrated in the appended drawings, wherein:: Figure 1 is a schematic general view of an apparatus for producing two-component thread, embodying the invention; Figure 2 is a view taken along arrow line A in Fig. 1, according to the invention; Figure 3 is a fragment of the schematic view of Fig. 1, with the hollow cylinder being connected to the sensor through a linkage, according to the invention; Figure 4 is a fragment of the schematic view of Fig. 1, with the hollow cylinder being connected to the sensor through a linkage and being also operatively connected with the drive, according to the invention; Figure 5 is a fragment of the schematic view of Fig. 1, with the hollow cylinder arranged in the zone of winding of the reinforced thread, forming a part of the winding unit, in accordance with the invention;; Figure 6 is a fragment of the schematic view of Fig. 1, with the hollow cylinder engaging a delivery shaft to form a delivery couple, in accordance with the invention; Figure 7 is a view taken along arrow line B in Fig. 6, according to the invention; Figure 8 is a partly longitudinally sectional view illustrating in more detail the structure of the hollow cylinder according to the invention; Figure 9 is a view taken along arrow line D in Fig. 8, according to the invention; Figure 10 is a perspective view illustrating in more detail the delivery couple with the core thread passing into the slit of the hollow cylinder toward the blade of the knife, according to the invention; Figure ii illustrates the structure of the hollow cylinder with two flat knives, in accordance with the invention;; Figure 12 illustrates the structure of the hollow cylinder with three flat knives, in accordance with the invention.

The apparatus for producing two-component thread, e.g. reinforced thread, embodying the invention, comprises a can 1 (Fig. 1) with a supply of fibrous sliver 2, a roller 3 for feeding the sliver 2 and means for feeding separated loose fibres, in the form of a device 4 for breaking up the sliver 2 into individual loose fibres and feeding them into a twisting member 5.

The apparatus further comprises a holder of a bobbin 6 with a supply of the core thread 7, and a unit for winding the reinforced thread, including a holder of a package 9 engaged by a driven friction roller 9. Arranged intermediate the twisting member 5 and the winding unit along the path of the reinforced thread is a hollow cylinder with a slit 11 whose thickness is less than the thickness of the reinforced thread 12 but greater than the thickness of the core thread 7, adapted to be contacted by the running reinforced thread 12 and having the axle 13 for its rotation operatively connected with a drive 14.

To terminate the feeding of loose fibres from the device 4 into the twisting member 5, there is arranged intermediate the twisting member 5 and the hollow cylinder 10 in the path of the running reinforced thread 12 a sensor 15 with a feeler 16 adapted to be engaged by the reinforced thread 12, electrically connected with the device 4.

To ensure proper reaction of the hollow cylinder 10 (Fig. 2), i.e. severing of the bare core thread 7 in the thread 12, the latter should run about the hollow cylinder 10, defining at the point of its engagement with the cylinder 10 an angle a short of 1800C. This partial wrapping or bending of the running thread 12 at the angle a is ensured by the corresponding position of the hollow cylinder 10.

To shorten the time of transmitting a signal in response to affected integrity of the reinforced thread 12, the axle 13 on which the hollow cylinder 10 rotates is preferably mounted on arms 17 (Fig. 3) pivoted on the sensor 15. In this embodiment of the invention the hollow cylinder 10 engaged by the reinforced thread 12 acts as the feeler 16 of the sensor 15. In this embodiment the hollow cylinder 10 is rotatable through a flexible friction transmission including sheaves 18 (Fig. 4) and a flexible endless driving member 19, the axis of one of the sheaves 18 being aligned with the pivot axis of the arms 17, and the axis of the other sheave 18 being aligned with the axis 13 of rotation of the hollow cylinder 10.

Alternatively, when the hollow cylinder 10 (Fig. 5) is arranged in the area of winding of the reinforced thread 12 in engagement with the package 8, it forms a part of the winding unit, performing the function of the driven friction roller 9 (Fig. 1).

In another modification, to enhance the uniformity of delivery and winding of the reinforced thread 12, there is arranged intermediate the twisting member 5 (Fig. 6) and the winding unit a delivery couple formed by a positively rotated delivery shaft 20 and the hollow cylinder 10. In this embodiment the hollow cylinder 10 is mounted for free rotation on its axle 13, to be rotated in operation by its engagement with the delivery shaft 20.

To minimize the local wear of the surface of the shaft 20, this embodiment incorporates a reciprocable traversing guide 21.

To ensure proper reaction of the hollow cylinder 10 (i.e. the severing of bar core thread 7 in the thread 12), the thread 12 in this embodiment should likewise run about the hollow cylinder 10 (Fig. 7) defining a bending angle at the point of its engagement by the delivery couple, which angle a < 180 is provided for by positioning the traversing guide 21 correspondingly.

According to the invention, the inner space of the hollow cylinder 10 (Fig. 8) has secured therein at least one flat knife 22 with a cutting blade 23 adjoining the slit 11. To make slipping of the core thread of the thread 12 into the slit 11 toward the blade 23 of the knife 22 easier, its end face 24 is skewed.

The hollow cylinder 10 of the presently described embodiment is structurally made in the form of two closed-end sleeves 25 and 26 fixed on the axle 13 and spaced by a gasket 27 which defines the width of the slit 11 and can be used to adjust this width.

A bracket 28 (Fig. 9) is secured to the inner wall of the hollow cylinder 10 for mounting the knife 22.

Fig. 10 of the appended drawings illustrates in more detail the delivery couple when the core thread 7 slips into the slit 11 of the hollow cylinder 10, toward the blade 23 of the knife 22.

Several blades 22 (Figs. 11 and 12) are preferably accommodated in the inner space of the hollow cylinder 10, arranged radially at uniform spacing in a plane perpendicular to the axis 13 of the cylinder 10. The exact number of the blades 22 is selected to correspond to the speed of rotation of the hollow cylinder 10 and the required time of severing the core thread 7.

Although the present invention has been described in connection with its embodiment in an apparatus for producing reinforced thread, it can be successfully employed in apparatus for producing other types of two-component thread, e.g. twisted sewing thread.

The herein disclosed apparatus operates, as follows.

The fibrous sliver 2 (Fig. 1) is fed from the supply can 1 by the roller 3 into the device 4 which breaks the sliver into separated loose fibres. The stream of separated loose fibres is fed into the twisting member 5. Simultaneously, the core thread 7 is unwound from the supply bobbin 6 and fed into the twisting member which is rotated for the fibres to become wound or twisted around the core thread 7, yielding the final reinforced thread 12 which leaves the twisting member 5 and is directed toward the winding unit, to be wound into the package 8 by the driven friction roller 9 and a traversing device (not shown).Along its path from the twisting member 5 to the winding unit, the reinforced thread 12 comes into contact at required tension with the hollow cylinder 10 rotated on its axle 13 from a drive 14, the thread 12 running about the cylinder 10 defining a bending angle a < 180 (Fig. 2).

Should the feed of loose fibres into the twisting member 5 cease for some accidental reason (e.g. when the feed sliver 2 is broken or exhausted), the remaining bare core thread 7 continues its motion and, while running about the surface of the hollow cylinder 10 over its slit 11, slips into this slit 11, slides along the skewing end face 24 of the knife 22 (Fig. 8) in the inner space of the cylinder 10 and is severed by engagement with the blade 23 of the knife 22 during the ensuing rotation of the hollow cylinder 10 (Fig. 10).

This precludes the bare core thread 7 being wound into the package 8, which reduces the waste of this core thread 7 and provides for saving the initial materials and stepping up the yield of standard two-component thread, while cutting the downtime required for servicing and maintenance.

When the bare core thread 7 is severed in the hollow cylinder 10, so that the tension of the thread 12 ceases, the feeler 16 (Fig. 1) of the sensor 15 is no longer supported by the running thread 12 and falls, causing the closing of contacts (not shown) in the sensor 15, and a single is sent via the electric circuitry to turn off the operation of the device 4. Simultaneously, the twisting member 5 and the winding unit may be desengaged.

In the embodiment illustrated in Figs. 3 and 4, the sensor 15 responds by sending a signal to the device 4 the moment the bare core thread 7 slips into the slit 11, so that the hollow cylinder 10 swings down accordingly, since in this embodiment the sensor 15 sendsa signal not in response to the dropping tension of the thread 12 as the core thread 7 is severed, but to the pivoting of the arms 17 jointly with the hollow cylinder 10, which may take place even before the core thread 7 is actually severed, and this could be of essential importance in some emergency cases, e.g.

when the separating mechanism in the device 4 becomes clogged with fibres, as the friction of compacted fibres against stationary internal parts of the device 4 might cause inflammation of the fibres. The hollow cylinder 10 being rotated in this embodiment by means of the flexible driving member 19 and the sheaves 18 whose axes of rotation are aligned, respectively, with the pivoting axis of the arms 1 7 and with the axis 13 of rotation of the hollow cylinder 10, the arms 17 are able to pivot freely as the cylinder 10 swings down in response to the bare core thread 7 slipping into the slit 11.

Alternatively, with the hollow cylinder 10 (Fig. 5) replacing the driven friction roller 9 (Fig. 1) in the winding unit as the means rotating the package 8 (Fig. 5), the construction of the apparatus is simplified, for it is no longer necessary in this case to incorporate the driven roller 9 with all the elements (not shown) required for its positive rotation.

In the embodiment illustrated in Fig. 6, the delivery couple arranged intermediate the twisting member 5 and the winding unit, its nip being formed by the positively rotated delivery shaft 20 and the hollow cylinder 10 engaged by it and mounted for free rotation on the axle 13, provides for enhanced uniformity of delivery of the reinforced thread from the twisting member 5 and its more regular winding into the package 8 in the winding unit. In this way the uniformity of the winding or twisting of the fibres around the core thread 7 in the twisting member 5 is enhanced, and the structure of the package 8 is also improved, with better arrangement of the thread in its successive layers.The traversing guide 21 of this embodiment, overlying the delivery couple and reciprocating the reinforced thread 12 axially of the delivery shaft 20, firstly, provides for reducing the localized wear (grooving) of the surface of the delivery shaft 20 from the running thread 12, and thus for minimizing the slack of the thread 12 in the nip of the delivery couple, and, secondly, provides for bending the path of the thread 12 (Fig. 7) at the nip of the delivery couple at an angle a < 1800, which is essential for the bare core thread 7 to slip into the slit 11 of the hollow cylinder 10 and becomes severed there should any fault in the reinforcing process occur.

With several knives 22 (Figs. 11 and 12) being accommodated in the inner space of the hollow cylinder 10, the severing of the bare core thread 7 becomes speedier, while the uniform spacing of the blades about the axis of the cylinder 10 precludes misbalanced rotation of the cylinder 10.

In the herein disclosed apparatus the effort applied to the core thread 7 for its severing is directed axially of this thread, i.e. axially of the twisting member 5, which prevents lateral loading of its bearings, reducing their wear and prolonging the service life of the apparatus. This situation is further enhanced by the use of the knife 22 with the blade 23, simplifying the severing of the core thread 7 and minimizing the effort required. Furthermore, with the hollow cylinder 10 monitoring the integrity of the reinforced thread 12 with practically no time wasted in its severing in response to a fault, an winding of bare core thread 7 into the package 8 is prevented, which reduces the waste of the core thread and thus helps to save the initial materials, while facilitating the servicing of the apparatus and reducing the downtime.

Claims (6)

1. An apparatus for producing two-component thread, comprising a twisting member, a holder of a bobbin with a supply of one component of the two-component thread, means for feeding the other component of the twocomponent thread into the twisting member, a unit for winding the two-component thread including a holder of a package having an axle for its rotation, and a device for severing one component of the two-component thread upon ceasing of the feed of the other component of the two-component thread, arranged intermediate the twisting member and the winding unit and including an element with a slit adapted to contact the two-component thread, the width of the slit being less than the thickness of the two-component thread and greater than the thickness of the one component of the two-component thread, this element being a hollow cylinder operatively connected with a drive, the slit in the cylinder being annular, and the inner space of the cylinder accommodating at least one cutting member with a cutting edge adjoining the slit.

2. An apparatus as claimed in Claim 1, comprising a sensor of breakage of the twocomponent thread, arranged intermediate the twisting member and the winding unit, electrically connected with the means for feeding the other component of the two-component thread and operatively connected through a linkage with the axle of rotation of the hollow cylinder.

3. An apparatus as claimed in Claims 1 or 2, comprising a delivery couple arranged intermediate the twisting member and the winding unit and including a delivery shaft and the hollow cylinder adapted to engage this shaft.

4. An apparatus as claimed in Claims 1 or 2, wherein the hollow cylinder is arranged in the zone of winding of the two-component thread, forming a part of the winding unit.

5. An apparatus as claimed in any one of the preceding Claims 1 to 4, wherein the inner space of the hollow cylinder accommodates a plurality of flat knives arranged at uniform spacing and parallel to the axis of the hollow cylinder.

6. An apparatus as claimed in any one of the preceding claims, substantially as hereintofore described and illustrated in the appended drawings.