Inner ring for spinning ring

Operatively connected with a spinning ring of a ring spinning or ring twisting machine is a tubular inner ring at a small distance, the upper limit or boundary of such inner ring being located at a higher position than the traveller guide surface defined on the spinning ring, in such a manner that unthreading of the thread, which no longer is tensioned by the traveller is rendered impossible. Also the inner ring and/or the spinning ring are provided with at least one slot-opening by means of which traveller debris can escape. Furthermore the distance of the outer upper edge of the inner ring from the traveller guide surface is to be chosen sufficiently large, so that upon restarting of the winding process the traveller does not collide with the inner ring.

BACKGROUND OF THE INVENTION 
The present invention concerns an inner ring on a spinning ring for ring 
spinning and ring twisting machines which is arranged coaxially inside the 
spinning ring, a gap-forming clearance being maintained, the upper 
traveller guide surface of which spinning ring is designed for taking up 
an inner traveller leg extending downward and outward. 
Lubricated spinning rings for twisting machines with a concentrically 
arranged, tubular inner ring are already known from the Japanese Utility 
Publication Sho No. 43-13305/68 (comp. German DE-GM No. 71 40 330), in 
which arrangement the inner ring merely serves for preventing 
contamination of the bobbin packages by broken thread or yarn ends thrown 
about and soiled by dirty or greasy machine parts. 
As the ring flange which takes up the circulating C-traveller, is located 
still too far away from the upper end of the inner ring, however, and as 
also the lower inner end of the traveller is located at about the same 
height as the upper edge of the inner ring, the inner ring cannot prevent 
unthreading of the thread or yarn downwardly along the inner leg of the 
traveller, if the thread or yarn tension is released, and especially if 
the thread forms loops during a stand-still of the spindle. Re-threading 
of the thread requires considerable operator effort and thus is extremely 
disadvantageous to an efficient and economic operation of a ring spinning 
or ring twisting machine. 
Furthermore, these rings show the disadvantage that between the spinning 
ring and the inner ring a closed annular chamber is formed, in which 
traveller debris and fly waste can accumulate, and which thus require 
periodic cleaning. This disadvantage prevails also in a known, similar 
spinning ring according to U.S. Pat. No. 1,861,249. 
Rings designed for non-unthreading travellers also are known (Japanese 
Utility Model No. 32263/74), which ring contains in the lower inner part 
of the flange guiding the traveller a groove, into which penetrates a 
traveller leg, bent intensely inwardly and ending upward. Furthermore a 
shoulder extending at an inclination downward and inward is provided on 
the inside of the ring, which shoulder serves as a traveller support 
surface while the spindle is at a standstill. 
A disadvantage of this solution, however, is that no standard traveller 
readily available on the market can be applied, and that insertion and 
exchange of the special traveller proves difficult. Furthermore, a ring of 
this type does not ensure reliable prevention of the unthreading of the 
yarn or thread. 
SUMMARY OF THE INVENTION 
It thus is an object of the present invention to avoid the disadvantages of 
the rings and travellers mentioned, and to propose auxiliary means for a 
spinning ring, which reliably prevent unthreading even in case of loop 
formation, and permit use of a standard traveller and of normal rings 
adapted for such travellers, and in which no accumulation of traveller 
debris and fly waste can form between the ring and the inner ring. 
This object is achieved by an inner ring constructed according to the 
invention, the upper end of which inner ring, for supporting the 
untensioned thread, is located at a higher position than the lower limit 
of the guide surface for the traveller leg on the unlubricated spinning 
ring. 
The upper, outer edge of the inner ring in this arrangement is to be 
located with respect to the guide surface of the traveller at such a 
distance that the traveller is started up without contacting the inner 
ring. 
This proves advantageous as the traveller is not influenced by the inner 
ring in any manner even during the phase of its start-up, in such manner 
that no additional thread or yarn breakages occur. 
The inner ring can be mounted onto the spinning ring by a slide fit or by 
press fit, in such manner that the advantage of the choice of materials is 
obtained. The inner ring also can be glued to the spinning ring. 
Particularly advantageous to manufacture is an inner ring which is part of 
a mounting body arranged on a ring rail of the machine for the spinning 
ring. An inner ring of this type can be manufactured economically using 
injection moulding processes and without considerable subsequent machining 
.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A ring rail 1 (FIG. 1) is equipped with a ring holder 2, into which an 
unlubricated spinning ring 3 is inserted and is clamped by clamping 
extensions 4 in a manner known as such (e.g. Swiss Patent CH-PS No. 458 
152). The spinning ring 3 is provided with an upper inner surface 5, on 
which rotates an inserted traveller 6. The yarn or thread 8 to be taken up 
on the bobbin package 7 is supplied from above to the traveller 6 through 
which it passes, leaving it at the back in tangential direction with 
respect to the bobbin package surface, and owing to the action of the 
centrifugal forces the traveller 6 contacts the ring with its inner leg 9 
extending downward and inward. The surface of the spinning ring 3 swept by 
the the traveller leg 9 is defined in this context as traveller guide 
surface 10. A tubular inner ring 12 supported concentrically by the bottom 
wall 11 of the ring holder 2 is arranged in such manner that its upper end 
or boundary 13 is located higher, by a vertical distance h, than the 
traveller guide surface 10 swept by the traveller leg 9 and having a lower 
limit B, and that its outer edge is located at merely such a distance a 
(FIG. 2) from the traveller guide surface 10, in such manner that the 
circulating traveller 6 in its various modes of operation has sufficient 
clearance in the gap. The dimension of this distance a (approximately 1 to 
2.5 mm at an inside diameter Dr of the ring of 45 to 55 mm) is determined 
by the traveller 6, which during the start-up phase is pulled toward the 
inside while the centrifugal forces are not yet active, and the inside leg 
9 of which also in this extreme position does not contact the inner ring 
12. The tubular inner ring 12 extends downward to a location below the 
ring rail 1. Its inside surface 15 is cylindrical, and its inside diameter 
Di exceeds the maximum diameter Ds of the bobbin package by the amount b, 
which takes care of the unavoidable deviation of the bobbin due to out of 
round effects. At a bobbin package diameter Ds ranging from 45 to 55 mm 
this radial distance b ranges approximately between 1.5 and 2.5 mm. In 
this manner also the frequently noticed formation of beards, i.e. small 
fibre bundles sticking out of the bobbin packages, is suppressed or 
reduced, respectively, which beard formation lends a rough and improper 
appearance to the bobbin package. The diameter Dr is about the same as the 
diameter Di. 
In the spinning ring 19 (FIG. 3) one or a plurality of slots 23 extending 
in circumferential direction can be provided which permit debris of broken 
travellers to be thrown out. In this arrangement the position of the slots 
23 advantageously is chosen such that the lower surface 24 of the slot 23 
and the upper surface 25 of foot 21 are located at the same height. 
In advantageous manner the ring holder 1 (FIG. 1) including the inner ring 
12 is formed as one injection moulded piece. The openings 16, evenly 
spaced along the circumference in the bottom wall 11 for saving material, 
in advantageous manner also serve as ejection openings for traveller 
debris of the inside traveller leg 9 thrown down after a traveller 
breakage, as the breakage occurs at the highly stressed arch or curved 
portion 17 (FIG. 2) of the traveller 6, and as the outer leg 9a only is 
thrown off freely. 
In FIG. 3 an alternative design embodiment shows a spinning ring 19 mounted 
into a bore 18 of the ring rail 1. Set into its lower inside surface 20 is 
an inner ring 22 provided with a reinforcing foot ring 21 which can be 
press fitted or glued in. The spinning ring 19 is provided with a normal 
flange 26 for a C-traveller 27. The diameter Di necessarily is smaller 
than the diameter Dr, as the inner ring 22 extends upward to between the 
traveller 27 and the bobbin package 7. For the distance c the conditions 
mentioned above for the distance a are required. The idling position of 
the traveller 27 is indicated with dash-dotted lines. 
In the alternative embodiment according to FIG. 4 the spinning ring 28 is 
provided with a cylindrical inside surface 29, which together with the 
outer surface of the inner ring 31 to be taken up forms a slide fit, in 
such manner that the inner ring 31 can be taken off easily for cleaning 
purpose. Instead of a slide fit also a press fit can be provided. The 
detachable inside or inner ring 31 can be made from plastic material or of 
another material which is less expensive than the material of the 
wear-resistant, i.e. higher quality material, of the spinning ring 28. 
In the last mentioned alternative embodiment according to FIG. 4 one or a 
plurality of slots 32 extending in circumferential direction are provided 
in the inner ring 31, which also permit traveller debris to be thrown out, 
the lower surface 33 of the slot 32 merging into the conical surface 34 of 
the spinning ring 28. 
The function and the action of the inventive inner ring now will be 
described and follows: 
As the spindle drive is stopped, or as the spindle is braked, the spindle 7 
comes to standstill within a short time. As the forces acting on the 
thread 8 during operation disappear (any possibly remaining residual 
tension being negligible), the thread 8 now drops under the influence of 
gravity, assisted by loop formation, along the traveller leg 9, which now 
no longer contacts the traveller guide surface 10, and reaches the 
position indicated in FIG. 2, in which the upper end 13 of the inner ring 
prevents any further descent of the thread, which thus cannot pass beneath 
the lower end 35 (FIG. 2) of the traveller leg 9. Unthreading of the 
thread 8 from the traveller 6 thus is practically excluded. 
As the spindle is re-started, the above mentioned sequence is reversed; the 
thread is tensioned again and slides back to its operative position to the 
arch or curved portion 17 of the traveller 6. 
Also in the re-starting phase unthreading thus is effectively suppressed. 
No time consuming re-threading work being required, spindle down-time 
periods are reduced and machine efficiency thus is increased considerably. 
While there are shown and described present preferred embodiments of the 
invention, it is to be distinctly understood that the invention is not 
limited thereto, but may be otherwise variously embodied and practiced 
within the scope of the following claims.