GB1558942A - Apparatus for ring spinning or ring doubling - Google Patents

Abstract

In the apparatus, the ring (22) is air-mounted freely rotatably and is driven by the traveller (21), and the spindle possesses, at the upper free end of its spindle shank (12), a spindle attachment (13), round which the thread (11) running to the traveller (21) is looped. The spindle attachment can also be designed as a so-called crown. This ensures that highly sensitive threads can be spun or twisted at extremely high spindle speeds. <IMAGE>

Description

(54) APPARATUS FOR RING SPINNING OR RING DOUBLING (71) We, ZINSER TEXTILMASCHI NEN GmbH, of Hans-Zinser Strasse, Postfach 1480, D-7333 Ebersbach, Germany (Federal Republic), a German Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the followingstatement: The invention relates to apparatus for the ring spinning or ring doubling of threads, including a spindle, a ring through which the spindle extends, and a traveller which in operation is entrained by the thread and can rotateonthering.

To enable extremely high spindle speeds to be obtained, it is known to provide pneumatic bearings for the ring and to drive it by means of the traveller, which is entrained by the thread. When the ring is run up from the stationary state initially the traveller rotates more rapidly than the ring, and synchronism between the traveller and the ring is only established after some time, i.e. the traveller will then no longer slide on the ring but instead, traveller and ring will have the same rotational speed. This synchronism is maintained, more particularly at operational speeds.Spinning or doubling with a ring supported on pneumatic bearing means and drive exclusively by the traveller which is entrained by the thread was hitherto provided only if the thread supplied to the traveller by a thread guide, disposed at a distance above the spindle and constructed as a so-called "eyelet", does not bear upon the spindle between the said thread guide and the traveller, or on the sleeve which supports the bobbin and is placed on the spindle, so thatthe thread balloon extends from the thread guide to the traveller. The thread tension in the region of the traveller is therefore propagated practically without restruction from the traveller through the thread guide to the delivery unit.The delivery unit, in the case of a spinning machine, refers to the pair of delivery rollers of the relevant draw frame, and in the case of a doubling frame it refers to the delivery mechanism which delivers the threads that are to be doubled with each other. Hitherto it was not possible to spin or double very sensitive threads, which readily tended to break due to insufficient twist and/or because of their light gauge at the extremely high spindle speeds which alone are efficient, because these speeds resulted in excessive thread tension and therefore in frequent thread breakages. Spinning or doubling of coarse threads, i.e. threads with low metric numbers or large titres hitherto also caused problems in the case of rings with pneumaticbearings.

In spinning or doubling devices in which the rings do not run in pneumatic bearings and in which the traveller therefore slides constantly on the ring during operation, it is known to provide a spindle extension at the top free end of the spindle, to which the thread runs through a thread guide situated at a distance above the said spindle extension, and the thread surrounds the said spindle extension so that spinning or doubling is performed without a thread balloon (balloon-free spinning or doubling) or with a so-called reduced thread balloon.Balloonfree spinning or doubling refers to the case in which the thread surrounds not only the spindle extension, but also the sleeve which is situated below the spindle extension and is placed on the spindle, and the bobbin which is wound on the sleeve, and is separated from the bobbin only immediately above the traveller, towards which it then runs. Spinning or doubling with a reduced thread balloon refers to the case in which the thread situated between the spindle extension and the traveller does not touch the sleeve which is placed on the spindle, or the bobbin disposed on the sleeve. This is achieved by the thread being deflected by a conical surface from the spindle into the thread balloon, at the bottom end of the spindle extension reg @@ @win@ @@ssurroundedbythethread.

In the presence of such a spindle extension surrounded by the thread, the latter receives its @@ is in the region above the spindle @xtension, i.e. in the region in which the @@br@ad basses from the delivery unit to the spmdle extension, and the thread tension in this thread region is very low so that the risk ofthreadbreakageisreduced.

By contrast, due to the pull required to draw the thread along its looped portions, the thread tension is very high in the region of the thread which passes through the travel @er.

It is an object of the invention to provide a spinning or doubling device by means of which it is possible to spin or double threads which are more sensitive than hitherto but under efficient conditions and at extremely highspindlespeeds.

The present invention resides in apparatus for the ring spinning or ring doubling of threads, including a spindle, a ring through which the spindle extends, and a traveller which in operation is entrained by the thread and can rotate on the ring, and in which the ring is pneumatically supported and in opera tion is rotatably driven by the traveller, and the top free end of the shank of the spindle has a spindle extension which in operation is surrounded by the thread passing to the traveller.

It has been found that despite the high thread tensions in the region of the traveller, the use of a spindle extension in combination with a pneumatically supported ring driven by the traveller permits more sensitive threads than hitherto to be spun or doubled without any risk of an increase in thread breakages and at the extremely high spinning speeds which are made possible by rings in pneumatic bearings. More particularly, it is possible to spin or double finer threads or threads with a lower twist -than hitherto at extremely high spindle speeds. Furthermore, the spindle speed can be made higher than was possible hitherto. A number of other unexpectedadvantagesarealsoobtained.

For example, the weight of the ring sup ported in pneumatic bearings or of the rotor which supports the ring can be made greater than hitherto, a feature which widens the field of application of rings with pneumatic bearings as regards spinning and doubling of coarser threads, reduces the cost of produc ing rotors and results in a higher air resis tance. The invention therefore extends the field of applicaton of rings with pneumatic bearings not only to threads which are finer than hitherto, but also those which are coarserthanhitherto.

It is also possible to use travellers which are heavier than those employed hitherto so that running up of the ring from rest results in greater acceleration of the ring and therefore more rapid running up to speed of the ring to synchronism with the traveller, so that the running-up times of the rings are shortened and traveller wear and the risk of thread breakage during running-up is reduced.This is particularly important if a single spindle and the associated ring of a spinning or doubling frame are stopped for the purpose of remedying a thread break and the spindle, after being released, runs up to the operating speed of the other spindles in the machine very rapidly so that the speed of the traveller is correspondingly rapidly raised to the operating speed and accordingly the speed difference between the traveller and the ring is extremely large immediately after the spindle is released, a feature which intrinsi cally greatly increases the risk of traveller and thread breakage.However, since the acceleration of the ring is now greater than was possible hitherto, the time of the starting phase is reduced and the risk of thread breakage and traveller breakage is reduced, and the risk of traveller breakage is addition ally reduced by the heavier and therefore thicker traveller. The invention therefore also facilitates the remedying of thread breaks on individual spinning or doubling devices during the normal operation of the remaining spinning or doubling devices on theaffectedmachine.

Comparison tests carries out on a spinning device constructed in accordance with the invention also surprisingly showed that the mean tear strength of the thread was- substantially nigner than that of an identical thread which was spun by conventional spinning devices.

Tests also showed that, without risking the formation of thread accumulation on the spindle extension, it is possible to operate with particularly low thread tensions in the region between the delivery unit and the spindle extension and such tensions are lower than those obtained with the use of a non-rotatably supported ring. A comparison test between a spinning device according to the invention and a-spinning device with a non-rotating ring yielded the following: at the maximum permissible spindle speed of approximately 13 000 rev/min of the spin ning device with the stationary ring, the thread tension-obtained between the draw frame and the spindle extension was approx imately twice as high as that obtained with the same spindle speed in a spinning device according to the invention under identical test conditions; the spinning devices were differentiated only by one -having the ring with the pneumatic bearing the pther havirig a -non-rotatable ring.In the spinning device according to the invention, the thread ten sion increased with an increasing spindle than the tension of the thread in the region in which the thread passes towards the spindle extension 13.

The ring 22 is pneumatically supported in a pneumatic bearing 26, more particularly an aerodynamic pneumatic bearing, which is of known construction, the details of which are therefore not shown. The bearing has a known rotor; the ring 22 is fixedly disposed as a separate component on or is integral with the rotor. The rotor is associated with a stator fixedly connected to the ring frame 25 and, in the case of an aerodynamic pneumatic bearing, the rotor and stator at adequately high rotor speeds produce an air cushion which alone supports the rotor. Under stationary conditions and a low rotor speeds, the rotor bears on the stator, or it is possible to arrange that external air is blown in between the stator and the rotor at such low rotor speeds to support the rotor by lifting it off the stator.An eddy current brake, not shown, can also be provided and can advantageously have a permanent magnet capable of producing a magnetic field which penetrates through an annular metallic member fixedly connected to the rotor and during rotation produces eddy currents therein to decelerate the rotor and therefore the ring.

The purpose of the eddy current brake is to set the required thread tension in the region ofthe thread balloon 23.

When the spindle shank 12 rotates, the traveller 21 is entrained by the thread which passes through it to the thread bobbin 20 at a speed which is slightly smaller than that of the spindle speed, due to the feed motion of the thread. The traveller 21, in turn, alone drives the ring 22 which is therefore supported so as to be freely rotatable about an axis of rotation which coincides with the axis of rotation of the spindle shank 12. Synchronism between the traveller 21 and the ring 22 occurs at operating speeds and where appropriate even at spindle speeds below the operating speed, i.e. the traveller 21 will then no longer slide on the ring 22 but is pressed thereagainst by the centrifugal force to such an extent as to remain in one position relative to the ring.At lower spindle speeds on the other hand the traveller slides on the ring, in which case it must rotate more rapidly than the ring 22 in the direction of rotation thereof. This effect is obtained automatically when the spindle is started. When the spindle runs down into the stationary state, this effect must be achieved bv corresponding deceleration ofthe ring ' 2 in known manner.

In the embodiment according to Fig. 2 the illustrated spinning device is provided for balloon-free spinning. A known crown 13'.

the circumference of which is provided with axial grooves 27. and which is fixedly or rotatably connected to the spindle shank 12.

serves as a spindle extension. The spindle shank 12 projects upwardly beyond the sleeve 19 which is placed on the spindle shank. The external diameter of the crown 13' corresponds approximately to that of the adjacent spindle shank region so that the thread 11 is not deflected into a thread balloon, as in the embodiment according to Fig.

1, but instead surrounds the spindle shank 12. the sleeve 19 and the thread bobbin 20 which is being wound on the sleeve, as far as a position close to the ring 22. The thread is separated from the thread bobbin 20 only briefly above the ring 22. which is rotatably supported in a pneumatic bearing 26, the thread then passing through the traveller 21 and returning to the thread bobbin 20 so that the thread is wound onto the sleeve 19. No thread balloon is therefore present between the spindle extension 13' and the traveller 21. The pneumatic bearing system for the ring 22 can correspond. without any changes.

to that according to Fig. 1 and does not thereforerequirefurtherexplanation.

As in the case of Fig. 1, the traveller 21 can slide on the ring 22 which is driven solely by the said traveller, and synchronism between the traveller 21 and the ring 22 is established atleastatoperatingspeedsofthespindle.

Each of the illustrated spinning or doubling devices is situated on a spinning or doubling machine containing a plurality of such spinning or doubling devices in one or more rowsinaknownmanner.

With the spinning devices according to the invention. it is possible to spin and double at spindle speeds which are generally higher than hitherto. More sensitive threads and, where appropriate. threads coarser than those used hitherto can be spun and doubled with a low number of thread breakages. The threads can be of any kind, such as cotton threads, wool threads, threads of plastics fibres or filaments, threads of fibre mixtures and the like. Very sensitive threads which have only very slight twists, such as low-twist wool threads and the like. can be efficiently spun at extremely high spinning speeds.

Threads having a twist which is lower than was economically possible for such high spindlespeedsean also be spun anddoubled.

If the pneumatic bearing system is purely aerodynamic. a feature which can be selected at will, the rotor of the pnematic bearing system is first rotated under mechanical friction on the stator when running up from rest, because the air cushion which supports the rotor is adequately formed only at higher rotor speeds of. for example, more than 6000 rev/min. When running up to the spindle operating speed. the mechanical friction of the rotor leads to an increased risk of thread fracture and it has been found that the invention counters this risk better than hitherto.

This does not alter the fact that it is generally particularly advantageous for the rotor of the pneumatic bearing system to be initially pneumatically supported by aerodynamic means using external air and to change over to aerodynamic pneumatic bearing operation by shutting down the external air supply whenthespindlespeedissufficientlyhigh.

It has also been shown that in many cases no eddy current deceleration for the ring is necessary at operating speeds. In such cases, it is therefore frequently possible with advantage to dispense with the eddy current brake and to provide a less expensive mechanical brake for decelerating the ring to the stationarystate.

Claims (10)

WHATWECLAIMIS:

1. Apparatus for the ring spinning or ring doubling of threads, including a spindle. a ring through which the spindle extends, and a traveller which in operation is entrained by the thread and can rotate on the ring and in which the ring is pneumatically supported and in operation is rotably driven by the traveller, and the top free end of the shank of the spindle has a spindle extension which in operation is surrounded by the thread passingtothetraveller.

2. Apparatus according to Claim 1 in which the spindle extension is a curved spinningfinger.

3. Apparatus according to Claim 1, in which the top end of the spindle extension hasacrown.

4. Apparatus according to any of the preceding claims, in which the spindle shank and the spindle extension are designed for balloon-free spinningordoubling.

5. Apparatus according to any of claims 1 to 3. in which the spindle shank and the spindle extension are designed for spinning ordoublingwithareducedthreadballoon.

6. Apparatus according to any of the preceding claims. in which the ring is pneumatically supported by aerodynamic means.

7. Apparatus according to any of claims 1 to 5. in which the ring is pneumatically supportedbyaerostaticmeans.

8. Apparatus according to any of claims 1 to 5. in which the pneumatic bearing system of the ring can be operated aerostatically and at higher speeds can also be operated purely aerodynamicalla .

9. Apparatus according to any of the preceding claims, in which the ring is associated with an eddy current brake arranged to deceleratesaidring.

10. Apparatus for ring spinning or doubling. substantially as herein described with reference to Fig. 1 or Fig. 2 of the accompanyingdrawing.