GB2255987A

GB2255987A - Ring spinning apparatus

Info

Publication number: GB2255987A
Application number: GB9210603A
Authority: GB
Inventors: Ernst Fehrer
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-05-21
Filing date: 1992-05-18
Publication date: 1992-11-25
Also published as: CN1075991A; KR920021763A; ITGE920057A1; JPH05179521A; ES2068082R; DE4215883A1; FR2676756A1; ITGE920057A0; CS152592A3; GB9210603D0; ES2068082A2; ES2068082B1; IT1257343B

Description

2 2-,59 37 j. 1 ' G RING SPINNING APPARATUS

BACKGROUND OF THE INVENTION 1. Field of the Invention

This invention relates to a ring spinning apparatus comprising a spindle, which is adapted to be driven and to be non-rotatably connected to a bobbin, and a guide ring, which is centered on the axis of the spindle and serves to guide a traveler, which revolves around the guide ring and serves to guide a yarn.

2. Description of the Prior Art

In ring spinning apparatuses the fibrous roving withdrawn from a drawing frame is twisted to form a yarn as it is supplied via a ring spinning guide to a bobbin, which is non-rotatably mounted an a driven spindle. The ring spinning guide generally consists of a traveler, which concentrically revolves about the.bobbin an a guide ring and has two legs, which straddle said ring on both sides of the track for the traveler, which constitutes an eyelet for guiding the yarn as it is supplied to the bobbin. As a result, the traveler is carried along by the yarn as it is wound on the rotating bobbli. Each revolution of the traveler will result in a twisting of the yarn by one turn. The speed difference between the leading bobbin and the trailing traveler will determine the velocity at which the yarn is being wound. Centrifugal forces are exerted on the traveler and on the fibrous roving as it is guided by the traveler around the bobbii and is thus twisted to form a yarn and in cooperation with the yarn-guiding forces cause a tiltino moment to be exerted an the traveler in a sense that is transverse to the track for the traveler. That. tiltinq moment increases the friction and in case of C Ch a substantial acceleration of the revolving traveler will result in an excessive temperature rise in continuous operation.

If the guide ring is also rotatably mounted (AT8 25,366), the frictional forces which are exerted between the traveler and the ouide ring ring will impart a rotation to the guide ring so that the velocity of the traveler relative to the guide ring will be decreased in case of a comparable velocity of the traveler around the bobbin. But owing to the tilting moment, which is exerted an the traveler under the centrifugal force, a considerable load will still be exerted on the traveler so that the useful life of the traveler will be substantially shortened during an operation at high speed.

SUMMARY OF THE INVENTION

For this reason it is an object of the invention to provide a ring spinning apparatus which is of the kind described first hereinbefore and which is so improved by simple means that the traveler will have a long useful life even if it is rotated at high speed.

The object set forth is accomplished in accordance with the invention in that a track for deflecting the yarn as approaches the traveler is provided adjacent to the guide ring andsurrounds the bobbin and the projections of the yarn portion moving from the deflecting track to the traveler and the yarn portion deoartinc4-From the traveler an a plane extending through the axis of the spindle and through the traveler include adjacent to the traveler an angle that is smaller than 90.degrees.

E3ecause a deflecting track is provided, which surrounds the bobbin and along which the yarn is guided as 1 4W the traveler revolves around the guide ring and by which the yarn is so deflected that an acute angle is defined adjacent to the traveler between the approaching yarn portion and the departing yarn portion, the tension of the yarn will cause the traveler to be subjected to a centripetal force, which opposes the tilting moment that is due to centrifugal force and which ensures that the traveler will assume a desirable sliding position. As a result, the frictional forces which are effective between the traveler and the guide ring will desirably be reduced so that a very long useful life will be ensured even if the traveler revolves at extremely high speeds.

The resultant yarn tension acting on the traveler is exerted along the bisector of the angle between the yarn portion which approaches the traveler and the yarn portion which departs from the traveler. 8ecause the course of the yarn portion between the traveler and the bobbin is predetermined within relatively narrow limits, the exertion of a sufficiently strong centrifugal force owing to the yarn tension will not be ensured unless the angle between the projections of the yarn portion which approaches the traveler and the yarn portion which departs from the traveler on a plane extending through the axis of the spindle and through the traveler include adjacent to the traveler an angle that is smaller than 90 degrees. With an angle thus defined the resultant of the yarn tension acting an the traveler will extend in such a direction that the traveler will assume a preferred sliding position and a larger axial distance can be provided between the guide ring and the deflecting track so that the traveler will be more easily accessible, particularly if said axial distance is at least 4 mm.

C Because the axial distance between the track for deflecting the yarn and the guide ring will influence the course of the yarn between the deflecting track and the traveler, the track for deflecting the yarn may be mounted to be axially adjuatable to permit a simple adaptation to the conditions in each case.

The effect of the deflection of the yarn by the deflecting track on the sliding position of the traveler will not depend-on whether the deflecting track is rotatably or non-rotatably mounted. If the guide ring is rotatably mounted so that the traveler can rotate at high speed, the deflecting track may be non-rotatably connected to the guide ring so that the frictional forces exerted between the yarn and the deflecting track will cause the guide ring to be subjected to a torque which assists the rotary drive of the guide ring without imposing an additional load an the traveler.

Because a rotation is imparted to the guide ring by the friction between the traveler and the guide ring and, if the track for deflecting the yarn is mounted on the guide ring, said rotation will be imparted to the quide ring also by the friction between the approaching yarn portion and the deflecting track, the quide ring will rotate at varying speeds because the resistances to the rotation and the frictional conditions will fluctuate. This will result in varying conditions for the guidance qf the traveler. In a design by which said guiding conditions are predetermined, the rotatably mounted guide ring can be driven to revolve at a predetermined velocity in the same sense as the traveler. In t hat case the useful life of the traveler will no longer depend an random conditions regarding the velocity at which the guide ring is revolving.

1 Because the guide ring is driven, the ring spinning anparatus can be started up under desirable conditions and that fact will also tend to prolong the useful life of the traveler. The guide ring may be driven by various means. If a plurality of ring spinning apparatuses are arranged in a bank, in the usual manner, particularly desirable driving conditions will be achieved if the drive is effected by a tangential belt. In that case the guide ring may be received by a bearing race, which Is constituted by the inner or outer bearing race of a rolling element bearing.

Inevitable variations regarding the yarn thickness will result in a variation of the diameter of the bobbin so that the yarn tensions must be expected to vary during a given revolution of the traveler and such varying tensions will adversely affect the sliding position of the traveler relative to the guide ring. To permit a compensation of such varying yarn tensions the track for deflectina the approaching yarn may be spaced from the spindle axis by a distance which varies between an upper limit and a lower limit along the periphery of the deflecting track so that vibrations will be generated in the yarn. Because the distance from the deflecting track to the spindle and to the bobbin, which is centered on the spindle axis, varies along the periphery of the deflecting track, the yarn approaching the traveler is caused to vibrate with an amplitude that depends on the predetemined difference between the upper and lower limits of the distance from the deflecting track to the spindle axis. Said vibrations will have a high frequency, which depends on the speed of the traveler, and will be superimposed on those vibrations of the yarn which tend to change the size of the yarn balloon and which are at a lower frequency. This superimposition will produce the surprising result 5lilw that the influence exerted by said lower-frequency vibrations of the yarn an the position of the traveler will be compensated and a eubstantially stable position of the traveler will be ensured; this is an important requisite for a long useful life of the traveler.

The high-frecuency vibrations can be generated in various ways- For instance, a circular track for deflectino the yarn which approaches the traveler may be eccentric to the spindle axis so that the deflecting track deviates from a circular path that is centered an the spindle axis; such a deviation is required for the generation of vibrations in the yarn. But such a simple design of the deflecting track will permit a generation of vibrations only at one frequency, which corresponds to the frequency of revolution of the traveler. If the yarn is to vibrate at higher frequencies, it will be necessary to provide a deflecting track which deviates form a circular configuration and has, e.g., an oval or elliptical configuration. In that case the deflecting track may be centered on the spindle axis.

It will be understood that the high-frequency vibrations of the yarn must not impose on the yarn an excessive additional load. To ensure desirable tension conditions it is recommendable to determine the difference between the uoper and lower limits for the distance from the deflecting track to the axis of the spindle in dependence on the length of yarn which is suoplied to the bobbin during each revolution of the traveler.

BRIEF DESCRIPTION OF THE DRAWING

Figure 1 is a schematic axial sectional view showing a ring spinninq apparatus in accordance with the application.

1 4b Figure 2 is a too Plan view showing that ring spinning apparatus partly broken away.

Figure 3 is a sectional view showing an a larger scale the quide ring and the course of the yarn adjacent to the traveler.

Figure 4 is a view that is similar to Figure 1 and shows a modified ring spinning apparatus in accordance with the invention.

Figure 5 is a schematic top plan view showing a bank of similar'rina spinning apparatuses.

Figure 6 is a schematic top plan view showing a further embodiment of a ring spinning apparatus in accordance with the invention.

Figure 7 is a view that is similar to Figure 3 and shows on a larger scale the course of the yarn adjacent to the traveler in the embodiment shown in Fioure 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the invention will now be described more in detail with reference to:the drawing.

In the illustrated embodiments the ring spinning apparatus essentially comprises a spindle 1, which is driven by conventional means and an which a bobbin 2 is nonrotatably mounted, to which a yarn 3 made from a fibrous roving is supplied through a conventional traveler 4, which constitutes a yarn-guiding eyelet and revolves aorund a guide ring 5. According to Figures I to 3 that guide ring 5 - a is held to be stationary. According to Figures 4 and 5 "he guide ring 5 is mounted in a bearing race 6, which is rotatably mounted by a rolling element bearing 7 in a holder S. That holder 8 may be inserted in a ring rail 9, just as the non-rotatable guide ring 5 shown in Fiugres I to 3. If the guide ring 5 is rotatably mounted, the velocity of the traveler relative to the guide ring 5 can be decreased without a decrease of the speeds of the traveler 4 relative to the bobbin 2 and the rino rail 9 so that the load on the traveler-will be-reduced.

Independently of the rotatable mounting of the guide ring 5 it is desired for the traveler 4 to assume a desirable sliding position relative to the guide ring 5. This is accomplished by the provision of a deflectino track 10, which is constituted by a slide ring that surrounds the bobbin and is arranged above the guide ring 5 at a small axial distance therefrom and has a smaller inside diameter than the guide ring 5. The annular deflecting track 10 is supported by a mounting ring 11, which is mounted on the body of the guide ring 5 (Figure 1) or an the bearing race 6 (Figure 4) and carries angled mounting lugs 12, to which the deflecting track 10 is secured. In the embodiment of Figure 4 the circumferentially acting frictional forces between the deflecting track 10 and the revolving yarn 3 exert a torque an the guide ring 5 so that the latter is driven whereas the traveler 4 is relieved. To provide optimum conditions regarding the circumferential velocity of the guide ring 5, the guide ring 5 may be forcibly driven, e.g., by a tangential belt drive 13, which cooperates with the bearina race G. The tangential belt 14 of that tangential belt drive 13 drives the bearing race 6, which for that puroose comprises a crowned tread 15, which surrounds the holder 8 and is engaged by the I- t ' V^ tangential belt, as is shown in Figures 4 and 5. Owina to that measure an influence of variations of the resistance to the rotation, e.g., as a result of different lubrication conditions for the rolling element bearings 7, on the circumferential velocity of the guide ring 5 will be avoided.

The yarn 3 which has been deflected by the deflecting track 10 extends between the deflecting track 10 and the traveler 4 along such a path that the projections of the yarn portion 3a approaching the traveler 4 and the yarn portion 3b departing from the traveler 4 on a plane extending through the axis of the spindle 2 and through the traveler 4 include an acute angle_o, as is particularly apparent form Figure 3. The resultant force exerted on the traveler 4 along the bisector of the angle between the yarn portions 3a and 3b owing to the yarn tension will compensate any tilting moment exerted on the traveler 4 owing to centrifugal forces and that compensation will be sufficient to permit a uniform surface contact between the traveler 4 and the guide ring 5 and the load an the traveler will thus decisively be reduced.

But variations of the thickness of the yarn and of the conditions under which the yarn is being wound an the bobbin 2 may cause the yarn tension to fluctuate. Such fluctuations will be reflected by a change of the diameter of the yarn balloon which is formed by the yarn as it revolves around the bobbin and will influence the balanced position of the traveler 4. As a result, the traveler 4 may be tilted so that its wear may greatly be increased. To reduce that Influence to an insignificant degree, the configuration of the deflecting track 10 may differ from a circle which is concentric to the spindle 1, as is apparent from Figures 6 and 7. In that case the distance from the deflectino track 10 to the axis of the soindle will chanoe along the periphery of the deflecting track 10 between an upper limit a a and a lower limit a u and the variation of that distance will cause the yarn 3 to vibrate at a frequency which exceeds the frequency of the vibrations imposed on the yarn, e.g., by changing winding conditions. As a result, the traveler 4 will be stabilized in a preferred sliding position. In Figure 7 the course assumed by the yarn when the distance a is at its lower limit a U is indicated in phantom and the course assumed by the yarn 3 when the distance a is at its upper limit a 0 is indicated by a solid line so that the result of that measure is clearly apparent.

In the embodiment illustrated in Figures 6 and 7 the deflecting track has the configuration of an oval or an ellipse. But the provision of noncircular deflecting tracks is not essential for the generation of vibrations of the yarn 3. It will be sufficient to provide a circular slide ring, which is eccentric to the spindle 1, and the amplitude of the resulting vibrations can simply be adjusted by an adjustment of the eccentricity so that that amplitude can, e.g., experimentally be adjusted.

The deflecting track 10 need not be arranged above the guide ring 5. To provide very small angle0C, the deflecting track may be arranged within the guide ring 5 an the level of the orbit of the traveler 4.

Claims

I^ 1 1. A ring spinning apparatus comprising a spindle, which is adapted to be driven and to be non-rotatably connected to a bobbin, and a guide ring, which is centered an the axis of the spindle and serves to guide a traveler, which revolves around the guide ring and serves to guide a yarn, characterized in that a track for deflecting the yarn as approaches the traveler is provided adjacent to the guide ring and surrounds the bobbin and the projections of the yarn portion moving from the deflecting track to the traveler and the yarn portion departing from the traveler on a plane extending through the axis of the spindle and through the traveler include adjacent to the traveler an anole that is smaller than 90 degrees.
2. A ring spinning apparatus according to claim 1, characterized in that the track for deflecting the yarn has a smaller inside diameter then the guide ring.
3. A ring spinning apparatus according to claim 1 or 2, characterized in that the track for deflecting the yarn is mounted to be axially adjustable.
4. A ring spinning apparatus according to any of claims 1 to 3, characterized in that the track for deflecting the yarn is rotatably mounted.
5. A ring spinning apparatus according to claim 4, characterized in that the track for deflecting the yarn is non-rotatably connected to the guide ring, which is rotatably mounted.
6. A ring spinning apparatus according to any of claims 1 to 5, characterized in that the guide ring is rotatably mounted and adapted to be driven to revolve at a predetermined peripheral velocity in the same sense as the traveler.
7. A ring spinning apparatus according to claim 6, characterized in that the guide ring is adpated to be driven by a tangential belt.

e-- 4W
8. A ring spinning apparatus according to any of claims 1 to 7, characterized in that the track for dEflEcting the yarn is spaced from the spindle axis by a distance which varies between an upper limit and a lower limit along the periphery of the deflecting track so that vibrations will be generated in the yarn.
9. A ring spinning apparatus according to claim 8, charactetized in that the track for deflecting the yarn consists of a circular track, which is eccentric to the axis of the spindle.
10. A ring spinning apparatus according to claim 8, characterized in that the deflecting track has an oval configuration.
11. A ring spinning apparatus according to any of claims 8 to 10, characterized in that the difference between the upper and lower limits for the distance from the deflecting track to the axis of the spindle is determined in dependence on the lenoth of yarn which is supplied to the bobbin durina one revolution of the traveler.
12. A ring spinning apparatus, substantially as described hereinbEfore with reference to and as shown an the accompanying drawing.