US2457450A

US2457450A - Yarn tensioning device

Info

Publication number: US2457450A
Application number: US674494A
Authority: US
Inventors: Dewas Raymond
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-03-26
Filing date: 1946-06-05
Publication date: 1948-12-28
Anticipated expiration: 1965-12-28

Description

3 Sheets-Sheet 1 Filed June 5, 1946 u v m Q N & 13: R Inventor is, I Ra man c) Demms Attovn Dec. 28, 1948. R. DEWAS YARN TENSIONING DEVICE ,3 Sheets-Shut 2 Filed June 5, 1946 w. D v! Yd e OK I ML w w Q MR Dec. 28, 1948. R. DEWAS YARN TENSIONING DEVICE 3 Shocks-Sheet 3 Filed June 5, 1945 l'nvcwt 0v R ay mend Dewas y duh-4K Patented Dec. 28, 1948 UNITED STATES PATENT OFFICE- YARN TENSIONING DEVICE Raymond Dewas, Amlens, France Application June 5, 1940, Serial No. 674,494 In France March 28, 194.8

The invention relates to yarn tensioning devices which are used in particular in textile machines and which comprise two circular members called discs which are in contact with one another.

In one of these known types of tensioning devices, the discs which rest on one another are provided with central holes or orifices through which passes the spindle of the tension device, which is fixed to a support by one of its ends; the diameter of the hole of the lower disc which rests on a stationary ring being sufllcient to leave, between its circular edge and the spindle passing through it, an annular gap through which can be evacuated the material or the fluff which comes away from the yarn while it is passing through the device. The yarn passing between the two discs comes into contact with the spindle which limits the lateral movement thereof, and is braked by the pressure exerted on it by the upper disc.

In practice, it has been found that despite the more or less regular rotary movements imparted to the discs by the forward movement of the yarn, the material left by the yarn might succeed in obstructing the whole or a part of the annular gap of the lower disc, thereby suppressing the contact between the discs, so that'the yarn was no longer tensioned or was only insufficiently tensioned. r

Devices have already been proposed to obviat these drawbacks, but other difficulties have'then arisen.

The invention provides improvements in disc operated yarntensioning devices, by means of which not only are the above-mentioned drawbacks effectively eliminated, but a number of advantages are obtained at the same time which have made possible certain novel arrangements which in their turn procure further advantages, as will be apparent hereinafter.

According to the invention, a first improvement made in the kind of tension devices referred to, wherein discs provided with a central orifice rest one upon the other, consists in that the spindle 20 Chimp. (Cl. 242-) tral hole and not in the form of an annular opening which is the cause of the accumulation, thereby enabling the diameter of said hole to be reduced and, consequently, the size of the discs themselves, with the advantage which may accrue therefrom; a further result is that since the yarn, while it is passing through the device, no longer comes into contact with the spindle of the tension device, it can move transversely between the discs, whose surface it thus sweeps.

According to the invention, a second improvement, whose importance will be brought forward hereafter, consists in providing means to limit the amplitude of the jumps of the upper disc,

which constitute a serious drawback in that they are breaking the contact between both discs, which therefore, do no longer assure a continuous and regular braking of the yarn.

According to the invention, another improvement consists in that a plurality of sets or pairs of discs may be arranged in alignment with one another, thereby enabling a novel kind of disc tension device to be obtained, through which the yarn passes in a straight line without any bend or any braking action other than that determined by the upper discs.

It is known to place consecutively a plurality of sets or pairs of tension discs through which the yarn passes successively, the spindles of said tension devices being arranged approximately in an arc of a circle. But it has been found that the successive purchases or bends thus formed have an undesirable action on the yarn which, in certain cases, may get untimely out of the discs.

According to the invention, other improvements further relate to the particular shape of the lower and upper discs, to the arrangement of means for threading the yarn at the inlet of the tension device, which means are used, in particular, in the mascot the yarn being unwound through a discontinuous, irregular or jerky take in, and

also to constructional details, as will become apv of discs, with a yarn threading device,

Fig. 3 being a plan view thereof.

Fig. 4 is a view in side elevation of a modification of mounting of the disc-carrier rings.

Figs. 5 and 6 are views in side elevation of two modifications of mounting of the jump limiter.

Fig. '7 is a view in side elevation of a modification of construction of the jump limiter,

, Fig. 8 being a plan view thereof. I

Fig. 9 is a view in front elevation of'the yarn threading device of which a side elevation is shown in Fig. 2 and a plan view in Fig. 3.

Fig. 10 is a view in front elevation of a similarly constructed double threading device for the case of two tension devices arranged'side by side,

Fig. 11 being a plan view thereof.

Fig. 12 shows a construction wherein the lower disc is rounded and the upper disc is flat.

In Fig. 1 are shown the component members of tension devices comprising discs provided with a central orifice, which rest on one another, in

this case: a spindle I suspended by its head-- shaped end I on a fixed support 2, and alsoan upper disc 3 resting on a lower disc 4 which itself rests on a fixed ring 5 mounted at the end of the arm 6 of a support 1. The component members are however characterized,.according to the invention, on the one hand by the fact that the spindle I, which no longer has to act but as a centering and retaining means of the upper disc 3 alone, ends above the level of the plane of contact of said disc with the lower disc 4, which plane coincides with that in which the yarn 0 passes, and on the other hand by the fact that the discs 3 and 4 are of such cross-sectional shape'that the face of one of the discs, preferably the lower disc 4, which is intended to be in contact with the opposite disc, forms an annular flat portion 4, whereas the opposite disc, preferably the upper disc 3, forms, on its contacting face, an annular projection 3' which is adapted to rest against the flat annular surface 4', the run of the yarn a as it passes between these two annular surfaces imparting to the discs a rotary movement which contributes to the evacuation of the material detached from the yarn, through the central evacuation orifice 4", and said evacuation may be assisted by a sweeping action which may be effected by the yarn owing to the fact that, since it is no longer stopped by the lower part of the spindle I, it can, then, move transversely. The. arrangement of the fiat and curved portions of the discs 3 and i may bereversed, as shown in Fig. 12.

By the judicious arrangement and crossshaping of the discs 3 and 4, the extra thick portions of the yarn (bulges or knots) first come into contact with the annular fiat portion 4' of the lower disc, then, by bearing thereon, lift the upper disc 3 with the least possible force and therefore without appreciable increase of ten sion, such lifting being all the more readily efl'ected as the angle between the discs is exceptionally small (18 in the embodiment shown). Owing to this fact, the upper disc is less liable to vibrate and does not jump so high, hence the getting out of contact are less frequent and of shorter duration and the strain on the yarn is less severe. Then, each extra thickness of the yarn gets out of contact with the upper disc 3 in the same conditions of smoothness, then passes beside or over the evacuation hole l'j and again penetrates between the discs, then leaves them in the same conditions.

As in the known tension devices, the weight of the upper disc 3 can be adjusted by means of 4 loading rings 8 testing on a ring 8, made of felt for instance.

In order to limit and adjust the amplitude of the jumps of the upper disc 3, a device is provided'which consists, in principle, as shown in Fig. 1, of stop points which are located above the upper disc 3. on either side of and at some distance from the spindle I, and against which either the disc or its loading ring 3 abuts, said stop points being formed by the lower ends of two rods II supported by their upper ends by a cross member I2, the whole arrangement being shaped like a staple, through the middle of which passes a screw-threaded rod I3, the lower end ofwhich penetrates into a smooth bore II provided in the head I and the spindle I.

To adjust the height of the stop ends of the arms I I of the staple, it is only necessary to screw or unscrew the rod I3 the desired amount for I formed by the end of springs, preferably located inside the rods;

By means of this l p limiter, the period of break of contact between the discs is extremely short, so that the yarn is always kept taut, at least, when the tension device comprises a plurality of sets of discs. Modifications may be made in the method of mounting the jump limiters.

For instance. the rod I3, instead of resting in the bore ll of the spindle I, may be screwed therein; or, as shown in Fig. 5, the cross member I2 may be fixed to the end of the spindle I, the

locking being effected by the nut I5 pressing against the head I. Dr again, as shown in Fig. 6, the head I' may be surmounted by a screwthreaded. rod I3 on which is screwed and locked by the nut I5, the cross member I2 'of the jump limiter with arms II.

Similarly, the jump limiter may, as shown in Figs. '7 and 8, merely comprise two independent arms II placed in holes provided on the crossmember 2 on each side of the hole intended to receive the "spindle I, and locked by nuts I5.

According to another improvement, the tension device comprises a plurality of sets of discs (preferably from three to seven) through which the-yarn passes along a straight course. In the case in which the spindles I do not pass through the holes 4"-of the lower discs 4, the inserting of the yarn between the discs is effected on the side opposite that which is to be occupied by the yarn when it comes in the operative position; in other words, the yarn is made to penetrate into the device on the side of. the discs opposite the stop fingers I! to which reference will be made hereinafter. This yarn follows a straight course, thereby eliminating all additional bends and braking.

There is thus no objection to the first upper discs being loaded more than the last ones, or, at any rate, as much as the last ones, by means of the rings 3, thereby favouring the unkinking and thus contributing to enable the yarn to be given minimum .tension.

Such a construction of a tension device with a plurality of sets of aligned discs comprises. as shown in Figs. 2 and 3, a common support, having a plurality of spindles I, which is formed by an upper cross member- 2 of appropriate length ,to accommodate five heads I of spindles I, for instance, and also a common support for a pluescape sideways, stop fingers I! may be provided which are located on the opposite side to that on which the yarn is manually inserted between the discs, so that the presence of said fingers does not in any way hinder or complicate this operation.

Said fingers are formed by vertically hanging rods I! which are passed through holes provided in the upper cross member 2 and which are retained by their head H in the same manner as the spindles l.

The presence of these fingers I! may enable the construction of the tension device with a plurality of sets of discs to be simplified, in as far as the side cross member I supporting the stationary ring 5 can be eliminated. As shown in Fig. 4, the rods 11 are, in this case, locked on the upper cross member 2 by nuts 18 and their lower ends are bent at IT and replace the arms 6 for supporting the stationary rings 5.

The supporting rings 5 may be provided, in all the embodiments, with a packing ID, of shock absorbing material which may be slippery or not.

In the case in which use is made of spindles I passing through the two discs in the hitherto usual manner, the yarn is engaged between the fingers and the discs and inserted between the latter by passing it above the ends of the fingers.

A tension device having a plurality of sets of discs, involving the application of the improvements according to the invention, therefore definitely offers, as is apparent from the foregoing, numerous advantages, inter alia that of providing, with yarns of various natures, a smooth and constant tension whatever be the speed of the yarn and whether its drawor take in be continuous, discontinuous, irregular or jerky, thereby enabling the least possible tension to be applied, so that the yarn undergoes the least possible strain and that in the case of high twist, there is no risk of said twist being modified. Owing to this fact, breakages of theyarn or defects in the product obtained are considerably lessened or eliminated. Finally, owing to its design, the tension device as a whole reduces to the strictest minimum the harm caused by the fluff,

Another improvement according to the invention consists in the fact that, for the threading, a vertical plate i9 is provided which is' used in combination with a second plate 20 arranged parallel with and spaced a short distance apart from same, in order to form a yarn threading device by means of which threading by hand is readily and quickly effected.

ing nose 23 around which the yarn passes, and by following the upper inclined edge 24 of the recess,

said yarn is thus guided towards the centre of the plate to the end of a slit 25 extending the v recess 22.

The front plate 20, which is'cut of sheet metal,

has the appearance of a rectangle of which the left-hand side has a large recess 26 for the inlet of the yarn fed from the bobbin as it unwinds, and the upper edge 210i which is rounded in order to guide the said yarn to the end of said recess 26 which terminates in the shape of a slit 28. Said plate 20 is of sufficient size for there to be no danger of the yarn catching as it unwinds from the bobbin (not shown).

These twoplates are arranged parallel. with one another and are secured together by means of a small intermediate plate 29 and the whole arrangement is assembled by means of screws 30, the thicknessof said plate 29 determining the gap between the two plates l9 and 20, between which the yarn passes during the manual threading operation.

This operation is effected easily and, so to speak, instantly, by engaging the yarn in the recess 26 of the plate 20, then under the nose 23 of the plate IS, the insertion into the recess 22 being facilitated by slightly bending the nose 23, as

shown at 23', along a crease 23" (Figs. 9, 10 and 11).,

The yarn passing between the two plates, as shown at a. in Fig. 3, is threaded between the two ends of the

slits

25 and 28, the position of which is equivalent to the formation of an eye (as shown in Fig. 9). The yarn, after having then been inserted between the discs of the various sets of the tension device, is passed through a U-shaped guide 3| 'which is placed obliquely as shown in Fig. 3 and which closely holds the yarn a in its straight position while not preventing the thicker portions from passing, it being possible to turn the guide to enable the yarn to be shifted sideways the desired amount between the pairs of discs, in which case, and in order to allow of a corresponding transverse movement of the yarn as soon as it enters the tension device, the adjustment of the respective position of the

threading plates

19 and 20 may be effected in such a manner that the ends of the

slits

25 and 28 form the equivalent of an elongated eye.

In the case, for instance, of yarns having a high amount of twist, and if space is not available to enable a suificient number of sets of discs to be used, it may be advisable to form a bend at the inlet of the yarn into the tension device, so as to contribute to the unkinking of said yarn. Such a bend is obtained by adjusting the respective position of the threading plates [9 and 20 in I 11, the threading plate I9 is so shaped as to have,

such a manner that the ends of the

slits

25 and 28 give the portion of yarn passing from one plate to the other the bend a" shown in dotted lines in Fig. 3.

When two tension devices are mounted side by side, the rear plate may be shaped similarly to the plate 19, so as to form, in combination with a front plate similarly shaped to the plate 20, a double threading device.

For this purpose, and as shown in Figs. 10 and symmetrically arranged, two noses 23 and two slits 25, whereas the large threading plate 20 is provided with a single medial vertical slit which replaces the recess 26 and the edges of which, to-

wards the centre of the plate, taper outwardly on each side and form rounded edges 2! which guide the yarns respectively td the left and to by being sup rpd ed on those of the slits 25. form devices the respective eyes of the two tension mounted side by side.

One of the plates I! or 2. may be vertically separated in two through the middlethereof. so as to enable, by shifting its parts, either the equivalent of elongated eyes to be formed, or the portions of the yarn passing from one plate the other to be given the bent position as herein before explained. a

It is also possible to obtain a double threading device by completing the single threading device of Fig. 9 by its equivalent arranged symmetrically with respect to the edge of the plate 20 opposite the recess 26.

It is of course understood that, without deviatthe level. of the plane of contact of said upper; and lower discs.

2. A yarn tensioning device which comprises a V said fixed ring and having a central hole therein for the evacuation of the material or flufi which v becomes detached from the yarn as it passes being from the spirit of the invention, changes,

modifications and additions may be made, and also the use of equivalent means may be considered. For instance, the two first sets of discs may be closer together than thenext ones, whose inter-axial spacing may gradually increase, this being in order to prevent the yarn, which is still insufiiciently steady, from escaping from the first .set of discs and also in order to facilitate unkinking. Furthermore, the first set, for instance, may be staggered so that theyarn passes through the centre thereof, or nearer to its centre than.

in the subsequent sets. In addition, the lower discs 4 may be eliminated and replaced by the supporting rings 5 themselves, the circular edge of which is given a shape corresponding to that of the discs 4, the annular projections 3 of the upper discs 3, in this case, beingto come into contact with the smooth annular surfaces 4' of said supporting rings. r

It should be observed that the improvements relating to the absence of a spindle at the level of the plane of contact of the discs, to the shape of the discs and to the device having multiple sets of discs, may also be applied to tension devices in which the loading rings are replaced by springs, or act through the intermediary of springs.

On the other hand, and when the spindle ends above the level of the plane of contact of the discs, the upper disc need not have a central orifice and may in that case be centred on the spindle, for instance by means of a bush or a projection loosely engaged on or in a corresponding part of the spindle.

In the case in which two or more tension devices are mounted side by side, the upper cross members 2 may be connected together and optionally to the side cross members 1, or to the common side cross'member 1, in any appropriate manner, and. in particular by the underneath, externally, and similarly the assembly may be supported, also in anyappropriate manner, by the threading plates, or other members.

Finally, as regards the stop fingers ll, thme may be fixedby their base on a lower member.

I claim;-

l. A yarntensioning device which comprises a fixed support, a spindle secured by one'of its ends to said support and projecting downwardly therefrom, an upper disc rotatably mounted on tweensaid discs, the length of said spindle being limited so that itslower end is located above the level of the plane of contact of said upper and lower discs, and means for limiting the amplitude of the vertical'movement of the upper disc. A

3. A yarn tensioning device which comprises a fixed support, a spindle secured by one of its endsto said support andprojectlng downwardly therefrom, an upper disc rotatably mounted on said spindle, afixed concentric ring located besaid spindle, a fixed concentric ring located below and spaced apart from said upper disc, 9. lower disc adapted to rest on the upper face of said fixed ring and having a centralhole therein for the evacuation of the material or fluff which becomes detached from the yarn as. it passes between said discs, the length of said spindle being limited so that its lower end is located above the level of the plane of contact ofsaid upper and lower discs, and means for limiting the amplitude of the vertical movement of the upper disc, said means consisting in at least a stop located above said upper disc.

4. A yarn tensioning device which comprises a fixed support, a spindle secured by one of its ends to said support and projecting downwardly therefrom, an upper disc rotatably mounted on said spindle, a fixed concentric ring located below and spaced apart from said upper disc, a

lower disc adapted to rest on the upper face of said fixed ring and having a central hole therein for the evacuation of the'material or flufi which becomes detached from the yarn as it passes between said discs, the length of said spindle being limited so that its lower end is located above the level of the plane of contact of said upper and lower discs, and means for limiting the amplitude of the vertical movement of the upper disc, said means consisting in at least a stop located above said upper disc, on either side of and at some distance from said spindle.

5. A yarn tensioning device which comprises a fixed support, a spindle secured by one of its ends to said support and projecting downwardly therefrom, an upper disc rotatably mounted on said spindle, a fixed concentric ring located below and spaced apart from said upper disc, a

lower disc adapted to rest on the upper face of said fixed ring and having a central hole therein for the evacuation of the fluff or materialwhich becomes detached from the yarn as it passes between said discs, the length of said spindle being limited so that its lower end is located above the level of the plane of contact of said upper and end of said downwardly projecting rods acting as stops for limiting the amplitude of the vertical movement of said upper disc.

6. A yarn tensioning device which comprises a fixed support, a spindle secured by one of its ends to said support and projecting downwardly therefrom, an upper disc rotatably mounted on said spindle, a fixed concentric ring located below and spaced apart from said upper disc, a lower disc adapted to rest on the upper face of said fixed ring and having a central hole therein for the evacuation of the material or fluff which becomes detached from the yarn as it passes between said discs, the length of'said spindle being limited so that its lower end is located above the level of the plane of contact of said upper and lower discs, and at least two independent downwardly projecting rods secured to said fixed support on either side of said spindle, the lower ends of said rods acting as stops for limiting the amplitude of the vertical movement of' said upper disc.

'7. A yarn tensioning device which comprises a fixed support, a spindle secured by one of its ends to said support and projecting downwardly therefrom, an upper disc rotatably mounted on said spindle, a fixed concentric ring located below and spaced apart from said upper disc, a lower disc adapted to rest on the upper face of said fixed ring and havinga central hole therein for the evacuation of the material or fiufi which becomes detached from the yarn as it passes between said discs, the length of said spindle being limited so that its lower end is located above the level of the plane of contact of said upper and lower discs, downwardly projecting rods acting as stops for limiting the amplitude of the vertical movement of said upper disc, and resilient means at the lower end of said downwardly projecting rods.

8. A yarn tensioning device which comprises a fixed support, a spindle secured by one of its ends to said support and project ng downwardly therefrom, an upper disc rotatably mounted on said spindle, a fixed concentric ring located below and spaced apart from said upper disc, a lower disc adapted to rest on the upper face of said fixed ring and having a central hole therein for the evacuation of the material or fluff which becomes detached-from the yarn as it passes between said discs, the length of said spindle being limited so that its lower end is located above the level of the plane of contact of said upper and lower discs, the upper end of said spindle having a smooth bore therein, and a rod having an upper screw threaded portion, the smooth end of said rod being inserted in said bore, a transverse member having a central tapped hole therein adapted to screw on said rod and to be locked thereon by a nut, a downwardly projecting rod secured to each end of said transverse member and forming therewith a staple-shaped assembly, and resilient means at the lower end of said downwardly projecting rods for limiting the amplitude of the vertical movement of said upper disc.

9. A yarn tensioning device which comprises a fixed support, a spindle secured by one of its ends to said support and projecting downwardly therefrom. an upper disc rotatably mounted on said spindle, a fixed concentric ring located below and spaced apart from said upper disc, a lower disc adapted to rest on the upper face of said fixed ring and having a central hole therein for the evacuation of the material or fluff which 10 becomes detached from the yarn as it passes between said discs, the length of said spindle being limited so that its lower end is located above the level of the plane of contact of said upper and lower discs, at least two independent downwardly extending rods secured to said fixed support on either side of said spindle, and resilient means at the lower end of said downwardly extending rods for limiting the amplitude of thevertical movement of said upper disc.

10. A yarn tensioning device which comprises a fixed support, a spindle secured by one of its ends to said support and extending downwardly therefrom, an upper disc rotatably mounted on said spindle, a fixed concentric ring located below and spaced apart from said upper disc, a lower disc adapted to rest on the upper face of said fixed ring and having a central hole therein for the evacuation of the material or fluff which becomes detached from the yarn as it passes between said discs, said discs being so shaped that face of said lower disc which is adapted to come into contact with the upper disc has a fiat annular surface thereon, whereas the face of the upper disc forms an annular projection adapted to come into contact with the fiat annular surface of the lower disc.

11. A yarn tensioning device which comprises a fixed support, a spindle secured by one of its ends to said support, an upper disc rotatably mounted on said spindle, a fixed concentric ring located below and spaced apart from said upper disc, a lower disc adapted 'to rest on the upper face of said fixed ring and having a central hole therein for the evacuation of the material or fluff which becomes detached from the yarn as it passes between said discs, said discs being so shaped that the face of said lower disc which is adapted to come into contact with the upper disc has an annular projection thereon, whereas the face of the upper disc forms a flat annular surface adapted to come into contact with the annular projection of the lower disc.

12. A yarn tensioning system, which comprises a plurality of tensioning devices arranged in a row in mutual spacedrelation, a spindle secured by one of its ends for each of said tensioning devices and extending downwardly therefrom, an upper disc rotatably mounted on each of said spindles, a fixed concentric ring located below and spaced apart from each of said upper discs, a lower disc adapted to rest on the upper face of each of said fixed rings and having a central hole therein for the evacuation of the material or fluff which becomes detached from the yarn as it passes between said discs, the row of tensioning devices being so arranged that the yarn passing successively between the discs of each tensioning device follows a straight course.

13. Yarn tensioning system according to claim 12, wherein said tensioning devices are arranged in evenly spaced relation.

14. Yarn tensioning system according to claim 12, wherein said tensioning devices are arranged in progressively increasing spaced relation.

15. A yarn tensioning system, which comprises a plurality of tensioning devices arranged in a row in mutual spaced relation, 9. spindle secured by one of its ends for each of said tensioning devices and extending downwardly therefrom, an upper disc rotatably mounted on each of said spindles, a fixed concentric ring located below and spaced apart from each of said upper discs, a lower disc adapted to rest on the upper face of each of said fixed ringsand having a central 11 hole thereinfor the evacuation of the material or fiufi which becomes detached from the yarn as it passes between the discs, the length of said spindles being limited so that their lower end is located above the level of the plane of contact of said upper and lower discs, the row of tension devices being so arranged that the yarn passing successively between the discs of each tension device follows a straight course, and so, is enabled to move laterally in the system.

16. A yarn tensioning system, which comprises a plurality of tensioning devices arranged in a row in mutual spaced relation, a spindle secured by one of its ends for each of said tensioning devices, and extending downwardly therefrom, an upper disc rotatably mounted on each of said spindles, a fixed concentric ring located below and spaced apart from each of said' upper discs, a lower disc adapted to rest on the upper face of each of said fixed rings and having a central hole therein for the evacuation of the material or fluff which becomes detached from the yarn as it passes between the discs, the length of said spindles being limited so that theirlower end is located above the level of the plane of contact of said upper and'lower discs, the row of tension devices being so arranged that the yarn passing successively between the discs of each tension device follows a straight course, and is enabled to move laterally in the system, and

means for limiting the lateral movement of said yarn.

17. A yarn tensioning system which comprises a support formed by an upper transverse member and a lower lateral transverse member, a plurality of downwardly extending spindles secured by one of their ends to said upper transverse member and arranged in a row in mutual spaced relation, an .upper disc rotatably mounted on each of said spindles, a concentric fixed ring secured to said lower transverse member and located below and spaced apart from each of said upper discs, a lower disc adapted to rest on the upper face of each of said fixed rings and having a central hole therein for the evacuation of the material or fiufi which becomes detached from the yarn as it passes between said discs, the length of said spindles being limited so that their lower end is located above the level of the plane of contact of said upper and lower discs, the row of tension devices being so arranged that the yarn passing successively between the discs of each tension device follows a straight course.

18. A yarn tensioning system, which comprises a support formed by an upper transverse member and a lower lateral transverse member, a plurality of downwardly extending spindles secured by one of their ends to said upper transverse member and arranged in a row in mutual spaced relation, an upper disc rotatably mounted on each of said spindles, a concentric fixed ring secured to said lower transverse member and located below and spaced apart from each of said up per discs, a lower disc adapted to rest on the upper face of each of said fixed rings and having a central hole therein for the evacuation of the material or fluff which becomes detached from the yarn as it passes between th discs, the length of said spindles being limited so that their lower end is located above the level of the plane-of contact of said upper and lower discs, the row of tension devices being so arranged that the yarn passing successively between the discs of each tension device follows a straight course, and fingers secured by their upper end to said uppertransverse member and extending downwardly therefrom between each successive tension device, thereby preventing the yarn from leaving the discs sideways thereof.

19. A yarn tensioning system, which comprises a support, a plurality of downwardly extending spindles secured by one of their ends to said support and arranged in a row in mutual spaced relation, an upper disc rotatably mounted on each of said spindles, a plurality of downwardly extending fingers secured by their upper end to said support, said fingers being bent substantially at right angles intermediate their ends, a concentric fixed ring secured to the horizontal portion of each of said fingers and located below and spaced apart from each of said upper discs, 9. lower disc adapted to rest on the upper face of each of said fixed rings and having a central hole 'therein for the evacuation of the material or fiuif which becomes detached from the yarn as it passes between said discs, the length of said spindles being limited so that their lower end is located above the level of the plane of contact of said upper and lower discs, the row of tension devices being so arranged that the yarn passing successively between the discs of each tension device follows a straight course, the substantially vertical portion of said fingers extending between each successive tension device and preventing the yarn from leaving the discs sideways thereof.

20. 'A yarn tensioning system according to claim 18, wherein means associated with the upper transverse member are provided for guiding the yarn as it comes out of the discs of the last tensioning device.

RAYMOND DEWAS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Swanson Dec. 16, 1947