US2718748A

US2718748A - Travellers for ring spinning, twisting, and doubling frames

Info

Publication number: US2718748A
Application number: US322414A
Authority: US
Inventors: Colbeck Albert Gustav Arthur; Thorpe Frederick George
Original assignee: Morgan Crucible Co PLC
Current assignee: Morgan Crucible Co PLC
Priority date: 1951-11-30
Filing date: 1952-11-25
Publication date: 1955-09-27
Anticipated expiration: 1972-09-27

Description

Sept. 27,' 1955 A. G. A. COLBECK ETAL 2,713,743

TRAVELLERS FOR RING SPINNING, TWISTING, AND DOUBLING FRAMES Filed Nov. 25, 1952 3 Sheets-Sheet l i F/GJ.

Ii /5 7 I r I I v @13 Inventors A LBEET GU: TA 1/ A/ev-Hue C OLBECK.

f'espse/cKGaoecz THOBPE.

Attorneys Sept. 27, 1955 A. G. A. COLBECK ETAL 2,713,748

TRAVELLERS FOR RING SPINNING, TWISTING, AND DOUBLING FRAMES Filed Nov. 25, 1952 3 Sheets- -Sheet 2 In ventors A 1.5527- GusrA 1 AETHUE COLBECK FIeEDEE/cK Gaza/ac: 7740EPE.

Aliorgneys P 7, 1955 A. G. A. COLBECK ETAL 4 TRAVELLERS FOR RING SPINNING, TWISTING, AND DOUBLING FRAMES Filed Nov. 25, 1952 3 Sheets-Sheet 5 Inventors A z BEIIET GU57?! vA/arHu/e Cons-5cm fTeEoEE/c/r GEO/es: Woe/=2:

Attorneys United States Patent 0 TRAVELLERS FOR RING SPINNING, TWISTING, AND DOUBLING FRAMES Albert Gustav Arthur Colbeck, Dorking, and Frederick George Thorpe, New Malden, England, assignors to The Morgan Crucible Company Limited, London, England, a British company Application November 25, 1952, Serial No. 322,414

Claims priority, application Great Britain November 30, 1951 12 Claims. (Cl. 57-125) operations in the production of spun yarns and the like from natural and/0r artificial fibres.

In these operations the fibres to be spun (hereinafter referred'to as the unspun yarn although they may have an initial twist in some cases) are usually drawn from a supply source, e. g. a package or drafting device, and

threaded through a traveller free to move around its doubling ring of a doubling frame, the unspun yarn then passing to a rotary take-up device such'as a bobbin, for example, mounted upon a spinning spindle arranged coaxially'with the said doubling ring, the yarn being wound, during the doubling operation, on to the said take-up device at a high speed and the traveller racing around its doubling ring at a very high speed and imparting twist to the yarn, the degree of twist depending on the speed of rotation of the spinning spindle and other factors as is well known in the art. Usually the yarn passes downwardly to its traveller and then on to the take-up device within this ring although the reverse arrangement is possible.

Doubling rings of many cross-sectional forms have hitherto been used and proposed in combination with a variety of differently shaped travellers, but this invention is concerned with a traveller for a doubling ring of the so-called vertical type comprising a substantially cylindrical annulus (which may be peripherally flanged between its upper and lower ends for fixing purposes) arranged with its axis vertical and constituting the traveller race and adapted to be disposed usually coaxially with the spinning spindle, said traveller being fundamentally of the so-called C-shape and-having its upper and lower hooked portions respectively hooking over the upper and lower ends of the doubling ring whilst leaving the traveller free to run around the ring, and the intermediate portion of the traveller which connects the said hooked portions of the traveller together being so shaped that a part thereof is adapted, when the traveller is in motion, to bear upon a vertical or. substantially vertical peripheral surface (usually the inner one) of the doubling ring. Usually the travellers are formed of metal wire whilst the doubling rings are generally made of forged steel and have their upper and lower ends of rounded convex crosssectional form.

Many expedients have been tried to effect lubrication of the doubling rings in order to reduce the friction between such rings and their travellers, but one of the more satisfactory solutions has been to produce the doubling rings of self-lubricating material and preferably of sintered metal (e. g. iron) according to the principles of powder metallurgy, the rings including a small percentage of graphite to assist lubrication and having the inter-- granular interstices, which are of capillary dimensions, initially charged or supplied with lubricating oil, these sintered rings being highly polished, at least along the upper and lower end bearing surface areas where they are likely to be engaged by their travellers.

The present invention is especially concerned with sintered metal doubling rings and travellers therefor but it may also be applied to forged steel and other doubling rings and their travellers.

Because of their self-lubricating properties it is highly desirable that sintered metal doubling rings should be used, but, because the special steps and apparatus necessary to form such doubling rings with transversely rounded upper and lower bearing surfaces have rendered the rings relatively costly, it has not been an economical possibility to use round ended sintered doubling rings whilst square ended sintered doubling rings have not been satisfactory due to the relatively rapid wear of the travellers caused by the square corners of the rings. Similarly, although vertical doubling rings of forged steel and the like which are of rectangular or similar cross-sectional shape so that they have fiat bearing surfaces at their square-cornered upper and lower ends have been illustrated in some prior patents, for example U. S. Patent No. 2,367,361, the rings which have been used in practice have been transversely rounded at their upper and lower bearing surfaces so as to eliminate from the ring the said inner and outer square corners which would, if present, cause undue wear on the travellers and require too frequent replacement of the latter as well as give rise to numerous other difiiculties such as the frequent jam ming of the travellers, particularly at starting. It is therefore one object of this invention to provide an improved form of traveller which may be used with vertical doubling rings, especially sintered metal doubling rings, having fiat or squared or substantially squared upper and/ or lower ends (all hereinafter called, for brevity, square ends) without any materially detrimental results on the doubling operations.

According to one feature of this invention there is provided a traveller for use on a vertical doubling ring having at least one square end, such traveller having hooked portions adapted to engage respectively over the upper and lower ends of the doubling ring and having at least one of the said hooked portions furnished medially with an inwardly directed bearing part or lobe adapted, when the traveller is applied to the doubling ring, to lie adjacent to, and to bear either initially or when the traveller is in motion upon, the bearing surface at a square end of the doubling ring and to maintain those parts of the said hooked portion of the traveller which adjoin and lie on each side of the said bearing part or lobe out of contact with the said doubling ring.

Preferably the parts of the traveller located immediately adjacent to and on each side of a bearing part or lobe above described, are so shaped as to be quite clear of the corners of the adjacent square end of the doubling ring when the traveller is in position on the latter. cording to a further aspect of the invention there is provided a traveller for use on a vertical-type doubling ring having at least one square end of which the bearing sur-- face is flat or substantially flat and meets the inner and outer peripheral surfaces of the ring at or substantially at right angles, the said traveller having hooked portions for engagement over the upper and lower ends of the doubling ring and having each hooked portion thereof which is to co-operate in use with a said square end of the doubling ring, furnished, between its inner and outer extremities, with a medial inwardly directed bearing part or lobe for co-operation with the bearing surface at the square end of the doubling ring whilst the intermediate portion of the traveller is adapted to bear upon a (i. e. the inner or the outer) peripheral surface of the doubling ring, the parts of the hooked portion of the traveller that adjoin and lie Thus acon the two sides of the bearing part or lobe of such hooked portion of the traveller being splayed or looped divergently outwardly at the inner and outer corners thereof on each side of the said bearing part or lobe, whereby the said corners of the said hooked portion of the traveller will be maintained clear of the inner and outer corners of the square end of the doubling ring when the traveller is in use thereon.

Considering the case where the yarn passes downwardly through the traveller to the take-up device, it will be noted that the upper hooked portion of the traveller will, when the traveller is stationary, rest upon the upper bearing surface of the doubling ring whilst the lower hooked portion of the traveller will hang vertically below the said upper hooked portion and will be located at some distance below the lower bearing surface of the doubling ring. On starting the doubling operation the resultant of the drag on the yarn and the pull exerted on the yarn by the takeup device will cause the traveller to rise until its lower hooked portion contacts the lower bearing surface of the doubling ring and the upper hooked portion (through which the yarn is threaded) of the traveller to move forwardly so that the traveller assumes a heeled over or oblique position with respect to the upper and lower edges of the doubling ring, at which stage the upper hooked portion as well as the lower hooked portion of the traveller may engage the doubling ring.

Assuming that at least the upper end of the doubling ring is square, then by providing the upper hooked portion of the traveller with a bearing part or lobe as above described, the starting friction and drag arising between the traveller and the doubling ring when the traveller has reached the said heeled over position will be reduced. Similarly if, as assumed, the yarn travels downwardly through the traveller and the doubling ring has at least its lower end of square form, then, by providing the lower hooked portion of the traveller with a bearing part or lobe as above specified, the running freedom of the traveller will be improved due to reduced friction and drag since, in a simple two ended traveller, it is the lower hooked portion of the traveller which engages, the doubling ring when the traveller is in motion, the upper hooked portion of the traveller being, at this stage, held by the yarn clear of the upper end ofthe doubling ring.

Although doubling rings may be made which are rounded at one and square at' the other, this would not ordinarily be economically a preferred method of making the rings particularly from sintered metal and, with the latter material at least, it would be much easier and cheaper to make the ring square at both ends. In such a case each of the hooked portions of the traveller adapted to co-operate with a square end of the doubling ring would preferably be formed with the said bearing part or lobe and be outwardly splayed on each side of the latter as already described. Forming the traveller in this way with a bearing part or lobe at each hooked portion liable to engage the doubling ring reduces the possibility of the traveller jamming on the doubling ring as well as reducing the friction and drag between the traveller and the ring.

Shaping the hooked portion or portions of the traveller to provide it with a bearing part or lobe for co-operation with a square end of a doubling ring as above described, and splaying or looping divergently outwardly the parts of each such hooked portion on each side of said bearing part or lobe has the effect of protecting the hooked portionof the traveller from wear by the sharp corners of the adjacent square end of the doubling ring as well as reducing, as aforesaid, the friction and drag between the traveller and the doubling ring and the danger of the traveller jamming on the doubling ring.

The or each of the said bearing parts or lobes of a traveller is so shaped as only to bear on a narrow area (substantially less than the whole radial width) of the co-operating bearing surface of the doubling ring on which the traveller is to be used and preferably is so shaped as only virtually to" make point contact with the said bearing surface.

The or each of the said bearing parts or lobes of the traveller may be provided, for example, by forming the corresponding hooked portion of the traveller of a concavo-conveXo-concave sinuous or serpentine form (rather like the capital E written in script) or by providing a loop or eye in such hooked portion, as will be more fully described hereinafter. Nevertheless, although certain shapes for the hooked portions of the travellers are described herein by way of example, it should be understood that these parts may be given other forms within the scope of this invention so long as each alternative provides a bearing part or lobe and good clearances between the traveller and the doubling ring at the inner and outer corners of the latter.

The invention also resides in the combination of a vertical type doubling ring which is square at its upper and/or lower ends, and particularly one which is square at both its upper and its lower ends, with a traveller hav-' ing each of the hooked portions thereof, which is adapted to engage a square end' of the ring, provided with a bearing part or lobe as aforementioned, the invention thus enabling a simplification and cheapening of the manufacture of the doubling rings by avoiding the necessity for rounding the upper and lower edges thereof, and making it especially easy to use sintered metal rings which are eminently suitable for the purpose.

Where the traveller is formed with two hooked portions arranged in a single common plane and respectively adapted to hook over the upper and lower edges of the doubling ring, the length of the traveller from top' to bottom has to be such as to reduce as far as possible the danger of the traveller jamming" or locking frictionally on the doubling ring, particularly at the commencement of a doubling operation, but, on' the other hand, the extent to which the length of the traveller can be increased is limited by the necessity of safeguarding against the traveller jumping off the doubling ring, principally when starting.

If when the traveller has fully heeled over at starting as above described, the angle which the intermediate part of the traveller makes with a vertical plane radial to the doubling, ring and passing through one end of the traveller, is less than the angle of friction for the particular traveller and ring, then the traveller will jam on the ring. Hence the arrangement should be such that the said heeling angle is greater than the angle of friction and consequently the traveller should be made of such a length, with respect to the depth of the doubling ring, as to achieve this result. However, if the traveller is made long enough completely to avoid the aforementioned jamming and high initial friction, then, as previously stated, the traveller may become unstable and prone to jump off the doubling ring: thus a compromise has hitherto had to be made and relatively frequent yarn breakages (due to the traveller jamming) and relatively frequent cases of the traveller jumping from the doubling ring (due to the excessive length of the traveller) have had to be borne, and this difficulty will not entirely be avoided even with travellers of the bearing part or lobe-provided form above described. v

It has alsobeen found hitherto that the end bearing surface of the doubling ring which is not normally contacted by a hooked portion of the traveller" when the latter is in motion (i. e. the upper bearing" surface in the case of a downwardly moving yarn) has not been conditioned by the traveller and has collected a deposit or film of sludge which has impeded the subsequent starting of the traveller from rest.

Therefore this invention also aims at providing a traveller having (-1) means for stabilizing the traveller on the doubling ring and thus for obviating or reducing the danger of the traveller; jamming: on the doubling ring,

particularly at starting, or of the traveller jumping off the ring whilst in use; and/or (2) means for conditioning, whilst the traveller is in motion, that end bearing surface of the doubling ring adjacent to the part of the traveller through which the yarn is threaded.

Thus according to a'further feature of this invention the traveller, instead of having only two hooked portions, one for engaging over the upper and the other for engaging over the lower bearing surface of the doubling ring, is provided with at least one further hooked portion for engaging over the upper or lower bearing surface.

of the doubling ring according to its purpose, i. e. whether it is intended primarily for stabilizing the traveller or for conditioning a bearing surface of the doubling ring. Thus, in the case of a traveller used with a downwardly moving yarn, the traveller may have a third hooked portion at its lower part and which trails behind the other upper and lower hooked portions of the traveller and engages under the lower bearing surface of the doubling ring to increase the stability of the traveller on the doubling ring. If this lower bearing surface is flat then the two lower hooked portions of the traveller are preferably both provided with the hereinbefore described bearing parts or lobes to reduce the friction and drag when these lower hooked portions of the traveller engage with the said bearing surface.

Alternatively the traveller may have an additional hooked portion serving as a wiper for engaging and conditioning that end bearing surface of the doubling ring not normally engaged by either of the other two hooked portions of the traveller when this is in motion on the doubling .ring, the said additional hooked wiper portion of the traveller being located in advance (in the direction of movement of the traveller) of the said other two portions. Thus a C-type traveller for use with a downwardly moving yarn, may be furnished with a forwardly located additional hooked wiper portion of suitable length which, engaging over the upper end of the doubling ring, bears, when the traveller is in motion and the yarn has raised and forwardly tipped the C-part of the traveller, lightly upon the upper bearing surface of the doubling ring so as to condition the latter as the traveller is drawn around the ring. The said additional hooked portion may be provided with a bearing part or lobe as above described, if desired.

If desired the traveller may have both a hooked wiper portion and a stabilizing portion; such a traveller would be virtually a combination of the last two travellers referred to.

.The doubling ring itself may be made of a self-lubricating material such as carbon or bronze but is preferably formed of porous, sintered powdered iron which may contain a proportion of graphite and be impregnated with oil.

In order that the invention may be more readily carried into practice certain embodiments of the same will now be described with reference to the accompanying drawings in which:

Figure 1 shows a C-shaped traveller having two-hooked portions and constructed inaccordance with this invention, the traveller being shown mounted on a doubling ring having square upper and lower ends;

Figure 2 is a view similar to Figure l, but showing a doubling ring in which the lower end is rounded instead of square, and illustrating a modification of the traveller illustrated in Figure 1;

Figure 3 is a view similar to Figure 2 but illustrating a modification of the traveller shown in that figure;

Figure 4 is a view similar to Figure l but illustrating a modified traveller combining features of that shown in Figure l with that shown in Figure 3;

Figure 5 shows, in perspective, a still further modified form of traveller constructed in accordance with this invention, this traveller having three hooked portions instead of only two;

Figure 6 diagrammatically illustrates the traveller. of Figure 5 in action on a doubling ring;-

Figure 7 is a fragmentary perspective view illustrating a further form of traveller having three hooked portions, the traveller being shown in operation on adoubling ring;

Figure 8 is a perspective view illustrating a modification of the traveller shown in Figure 7;

Figure 9 is a perspective view similar to Figure 7 but illustrating a further modified form of the traveller hav ing three hooked portions;

Figure 10 is a diagrammatic view illustrating the traveller of Figure 8 in use;

, Figure 11 is a perspective view of a still further modified form of traveller having three hooked portions;

Figure 12 is a perspective view of a still further modified form of traveller constructed in accordance with this invention and having four hooked portions.

Figure 13 is a perspective view of a modified form of traveller having three hooked portions and corresponding approximately to Figure 5;

Figure 14 is a perspective view of a still further modified form of traveller having three hooked portions an corresponding approximately to Figure 8; and

Figure 15 is a perspective view of yet another modified form of traveller having four hooked portions and cor responding approximately to Figure 12.

Figure 1 illustrates a vertically disposed doubling ring 1 upon which is mounted a double-ended or so-called C- shaped traveller 2 constructed in accordance with this invention.

The doubling ring 1 has square upper and lower ends which respectively constitute flat and horizontal bearing surfaces 3 and 4, the inner and outer surfaces 5 and 6 F of the doubling ring being cylindrical and the axis of the cylinder being perpendicular to the plane of the bearing surfaces 3 and 4.

The traveller has, at its upper and lower ends, hooked

portions

7 and 8 which respectively engage over the upper and lower ends 3 and 4 of the doubling ring, these hooked portions being connected together by an integral intermediate portion 9 which, when the traveller is in use, usually lies on the inside of the doubling ring.

Assuming that the yarn travels downwardly through the traveller to the spinning spindle, then when the traveller is at rest the upper hooked portion 7 thereof will rest upon the upper bearing surface 3 of the doubling ring whilst the lower hooked portion 8 will hang below and be clear of the lower bearing surface 4 of the doubling ring. 'However, as soon as the yarn commences to be drawn through the traveller it will apply an upward and forward thrust to the traveller and raise the upper hooked portion 7 of the latter from the upper bearing surface 3 of the doubling ring and bring the lower hooked portion 8 of the traveller into engagement with the lower bearing surface 4 of said ring.

As the traveller runs around the doubling ring, the outward movement of the traveller (due to centrifugal force) is restricted by the intermediate part 9 thereof engaging the inner surface 5 of the doubling ring whilst inward movement of the traveller with respect to the doubling ring is prevented by the end portions or extremities 11 and 12 of the traveller engaging against the outer surface 6 of the doubling ring, sufiicient clearance being provided between the intermediate portion 9 and the end portions 11 and 12 of the traveller to ensure that the latter shall have enough freedom to enable it to run readily around the doubling ring.

The two-ended traveller illustrated in Figure 1 has its upper and lower hooked portions each formed with a downwardly directed central or medial bearing part or lobe, the upper and lower lobes being respectively marked 13 and 14 in the drawings. The upper lobe 13 is adapted for engagement with the upper bearing surface 3 of the doubling ring whilst the similar lobe'14 7 is adapted for co-operation with the lower bearing surface 4 of such ring and each of the

lobes

13 and 14 is preferably so shaped that it has virtually only point contact with the adjacent bearing surface when engaged therewith.

The said bearing parts or

lobes

13 and 14 ensure that the hooked portions of the traveller are maintained out of contact with the bearing surfaces 3 and 4 except for the said point contact so that the drag and friction resulting from the engagement of the hooked portions of the traveller with the doubling ring are reduced and are considerably less than that encountered with the known forms of travellers.

On either side of its bearing part or

lobe

13 or 14, each of the said hooked portions of the traveller is splayed or' looped divergently outwardly away from the adjacent corner of the doubling ring. Thus the upper hooked portion 7 of the traveller is splayed or looped at 15 and 16 upwardly and outwardly more or less diagonally so as to ensure that the hooked end 7 of the traveller is entirely clear, when in use, of the

corners

17 and 18 of the doubling ring and the traveller is thus protected against wear by the

sharp corners

17 and 18. Similarly the lower hooked portion 8 of the traveller has the

parts

19 and 20 thereof on either side of its bearing part or lobe 14 divergently downwardly and outwardly splayed to such an extent as to ensure that the parts of the traveller on either side of the bearing part or lobe 14 will always be maintained out of contact with the

lower corners

21 and 22 of the doubling ring. Thus no disadvantage results from the use of a square ended doubling ring.

The intermediate part 9 of the traveller is somewhat outwardly cranked near its upper and lower ends at 23 and 24- so as further to assist in maintaining the hooked portions 7 and 8' of the traveller out of contact with the corners of the doubling ring and the extremities or end parts 11 and 12 of the

hooked portions

7 and 8 of the traveller are curved as shown (i. e. convexly with respect to the adjacent surface of the doubling ring) so that when these end parts are in engagement with the outer surface 6 of the doublingrin'gthey only contact the latter over a very small area.-

It'will be understood that, by forming the upper hooked portion 7 of the traveller with the said medial or hearing part or lobe 13 and the loops 15 and 16 so that the traveller, with the exception of the bearing part or lobe itself, is always spaced from the upper bearing surface of the doubling ring, it is ensured that, as previously explained,- at the commencement of the spinning operation the friction and drag between the traveller and the doublingring is very small. It will also be appreciated that by forming the lower hooked portion 8 of the traveller with a bearing part or lohe 14 and

loops

19 and 20 as described, the friction and drag between the traveller and the doubling ring will also be very small when the traveller is in operation and running around the doubling ring. It will also be appreciated that the friction and wear on the upper and lower ends of the doubling ring are reduced by forming the traveller as above explained and, in addition, the likelihood of the traveller jamming on the doubling ring is also greatly reduced, all as compared with the normal arrangements hitherto used.

As above explained the freedom of movement of a traveller in its own plane radially with respect to its doubling ring is limited by the co-operation of the intermediate part 9 and the extremities 11 and 12 of the hooked portions of the traveller respectively with the inner and outer surfaces and 6 of the doubling ring. Thus each of the said bearing parts or

lobes

13 and 14 should be so located between and spaced from the said intermediate part of the traveller and the said extremity of the hooked portion of the traveller, that, under all normal conditions of use of the traveller, the said bearing part or lobe will remain in vertical alignment with the co oper'ating bearing surface of the doubling ring and be unable to slip inwardly or outwardly in a radial direction from such surface. Thus the distance between the centre of the said bearing part or lobe and (a) the said intermediate part of the traveller and (b) the said remote extremity of the hooked portion of the traveller should be less than the radial width, but greater than half of the radial width, of the square end surface of the doubling ring with which the said bearingpart or lobe is to co-operate.

It should, of course, be understood that some advantage can be achieved by providing only one end of the traveller with a medial bearing' part or lobe: and divergent loops as above described and this would be particularly the case if only one end, e. g. the upper or the lower end, of the doubling ring were of square form instead of the usual rounded form. Thus, as will be seen in the arrange ment illustrated in Figure 2', the doubling ring 1' has a square upper end 3 and a rounded lower end 4' and the traveller 2 has its upper end precisely as shown in Figure 1 but has its lower end 8 of the form commonly used in the conventional traveller. With such an arrangement the initial drag of the traveller is reduced. It will be appreciated that the arrangement of Figure 2 could easily be reversed so that the lower end of the doubling ring is square and at the lower end of the traveller is of the sinuous or looped form whereby a reduction in the running as well as the starting friction of the traveller and also of the danger of jamming of the traveller on the doubling ring",- could be achieved. However,- in either of these two cases difiieulty would be experienced in manufacturing a round ended doubling ring (such as is shown) from sin'tered iron, although such a ring could be made from steel or other metal.

Figure 3 shows a traveller similar to that shown in Figure 2 with the difference that the medial bearing part or lobe 13 of the traveller is of a modified loop-like form as shown. It will be appreciated also that such a modified form of bearing part or lobe could be used at both ends of a traveller instead of the arrangement shown in Figure 1 if desired. Alternatively, this modified form of lobe could be used only at the lower end of the traveller or in combination with the other form of lobe shown in Figure 1. Thus, for example, Figure 4 illustrates a modified form of traveller used with a doubling ring 1 of the same form as shown in Figure 1 and wherein the traveller 2" has its upper hooked portion 7 of the same form as that shown in Figure 1, Whilst its lower hooked portion is of the form of the upper hooked portion shown in Figure 3. Thus the traveller of Figure 4 combines the two forms of bearing parts or lobes described respectively with reference to Figures 1 and 3.

It will, of course, be understood that whilst certain forms of the hooked portions of the traveller are herein described for reducing the friction between the traveller and the doubling ring and for enabling a square-ended doubling ring to be employed without harm to the traveller, nevertheless there are alternative shapes of the hooked portions of the traveller which could be employed in place of those illustrated and described but it is essential that all the alternative forms, if they are to meet the requirements of this invention, should provide bearing parts or lobes and good clearances at the inner and outer corners of the doubling ring.

As previously explained particular care has to be taken in dimensioning a traveller which is formed with only two hooked portions such as 7 and 8 arranged in a single plane and respectively adapted to hook over the upper and lower ends of the doubling ring as in the cases illustrated in Figures 1 to 4, for if such care is not taken there will be a marked danger of the traveller jamming on the doubling ring or flying from this ring in use, although by forming the traveller with bearing parts or lobes as above described, particularly with reference to Figures 1 and 4, the danger of jamming is clearly reduced.

However, with the object of still further safe uarding against the possibility of the traveller jamming on' the doubling ring in use, this invention provides a traveller having at least one additional hooked portion. The invention also provides for conditioning that end bearing surface (i. e. the upper bearing surface in the examples illustrated in the drawings) of the doubling ring adjacent to the part of the traveller through which the yarn passes and which part of the traveller would, while the traveller is running around the ring, not bear on the ring and thus would leave this bearing surface unconditioned or uncleaned. Thus the additional hooked portion of the traveller may be provided for one or the other of these two purposes (i; e. stabilizing or conditioning) or two such additional hooked portions may be provided one for each purpose and examples of each of these three alternatives, i. e. the provision of conditioning, stabilizing or anti-jamming, or both conditioning and stabilizing hooked portions will now be described by way of example.

Referring to Figure it will be seen that there is there illustrated a traveller 2" which comprises a main C-part basically the same as the traveller shown in Figure 1 but which has, at its lower part, an additional hooked portion 25 in all respects similar to the lower hooked portion 8 and connected to the latter in spaced parallelism by'a connecting part 26, the hooked portion 25 of the traveller being adapted to trail behind the

hooked portions

7 and 8 when the traveller is in motion as is indicated in Figure 6 where the yarn 27 is shown as passing through the upper hooked end 7 of the traveller. It will be appreciated that the traveller shown in Figures 5 and 6 is preferably used with a doubling ring 1 having a' flat bearing surface (3 or 4) at both its upper and its lower end and that the extra hooked portion or limb 25 is provided for traveller stabilizing purposes which will'be discussed further hereinafter. The alternative form of traveller shown in Figure 7 is fsimilar to that shown in Figure 1 (and is accordingly similarly referenced) but has an additional forwardly located hooked wiper portion 28 similar to the hooked stabilizing portion 25 already described, this wiper portion being connected to the intermediate part 9 of the main part of the traveller and having a central or medial bearing 'part'o'rlobe 13" like the other

hooked portions

7 and 8 of the traveller, the said bearing part or lobe always bearing upon the upper end of the doubling ring 1 for conditioning the same while the traveller is in motion. As will be seen the yarn 27 is threaded downwardly'through the upper hooked portion 7 of the main part of the traveller as shown in the drawing so that the traveller moves around the doubling ring 1 with the hooked conditioning portion '28 preceding or leading the main part of the traveller. As the traveller starts, the yarn 27 first lifts the rear part of the traveller and tilts the latter forwardly as hereinbefore described, but the arrangement is such that the lobe 13" of the hooked wiper portion 28 only bears lightly on the upper end of the doubling ring as will subsequently be explained with reference to Figure 10 of the drawings which shows the traveller of Figure 8 in operation.

Figure 8 illustrates a slight modification of the traveller shown in Figure 7 of the drawings but which is, in principle and operation the same as that shown in the latter figure.

Figure 9 illustrates a further modification of the arrangement shown in Figure 7 but in which the doubling ring 1 has a rounded lower end and in which the lower end of the main part of the traveller is of conventional form instead of being provided with a lobe or hearing part according to this invention,

Figure 11 shows an alternative shape of traveller having an additional stabilizing portion 25' but which could be inverted and used so as to provide a doubling ring conditioning or wiper portion. As will be seen this traveller is of substantially inverted Y-shape.

If desired the traveller may have both hooked wiper and stabilizing portions as previously explained'and such a traveller is shown in Figure 12, thisbeing in efiect a combination of the travellers of Figures 5 and 8.

It should be understood, however, that where the traveller is provided with the said additional hooked wiper and/or stabilizing portion or portions, this, portion or these portions should be so arranged as to improve or at any rate not materially to impede the'free running or starting of the traveller, and the hooked portions of a traveller including a wiper portion and/or a stabilizing portion should be so orientated with respect to one another and with regard to the depth of the doubling ring on which the traveller is to be used, that when the traveller is on the point of slipping, a straight line joining the point of contact of the traveller with the lower bearing surface of the doubling ring and the point of intersection of the lines of action of the forces acting through all the other hooked portions of the traveller makes, with a vertical plane radial to the doubling ring and passing through the said point of contact, an angle which is approximately equal to or greater than the angle of friction, that is to say the angle whose tangent is equal to the coefiicient of friction betwee the particular traveller and doubling ring.

The traveller illustrated in Figures 5 and 6, for example, has only one additional hooked portion namely a stabilizing portion 25, the traveller being of substantially reversed L-form when seen in side elevation, (i. e. looking at right angles to the axis of the doubling ring and from the inside of the latter), the upper hooked portion 7 acting, when the traveller is stationary, in a similar manner to the upper hooked portion of a C-type traveller, such as, for example, shown in Figure 1, Whilst the other two hooked portions 8 and of the traveller are, when the traveller is at rest, suspended below the lower end 4 of the doubling ring, the hooked portion 8 of the traveller possibly bearing lightly on the lower hearing surface of the ring. As the yarn 27 commences to pass downwardly through the hooked portion 7 of the traveller, this hooked portion is raised from the upper bearing surface 3 of the doubling ring in the more or less usual manner and the position of the traveller is altered with respect to the double ring, so that the bearing lobe of the hooked portion 25 of the traveller is brought into contact with the lower bearing surface 4 of the doubling ring and the bearing lobe of the hooked portion 8 of the traveller is lowered away from the said lower surface of the doubling ring, the arrangement being such that, when the traveller is on the point of slipping from its static position, a straight line 30 (see Figure 6) passing through the point of contact 31 of the yarn with the upper hooked portion 7 of the traveller and also through the point of contact 29 of the bearing lobe of the hooked portion 25 of the traveller with the lower surface 4 of the doubling ring, makes, with a vertical plane 32 radial to the doubling ring and passing through the said point of contact 29, an angle cc which is not less than but is approximately equal to or greater than the angle of friction for the particular traveller and doubling ring. Thus it will be seen that although the length of the traveller (considered from the point of view of stability) is the distance between the

hooked portions

7 and 8, the effective length (considered from the point of view of friction) is the greater distance between the point of contact 29 and the upper hooked portion 7, and therefore the traveller will be less likely than an ordinary C-traveller to jam on the doubling ring when starting from rest. A similar arrangement is adopted, as will be seen from Figure 10, in connection with a traveller having a hooked wiper portion 23 and no stabilizing portion; the yarn 27 in this case passes through the hooked portion 7 and, on this yarn being placed under tension, causes the traveller to assume a forwardly tilted position somewhat as indicated in Figure 10 in which the hooked portion 7 is raised from the upper end 3 of the doubling ring and the wiper limb 28 is brought into gentle contact With this end of the ring, the lower hooked portion 8 of the traveller being engaged with the lower end 4 of the doubling ring. A straight line 30, drawn through the point of interseetion 33 of the lines of action of the forces acting through the

hooked portions

7 and 28 of the traveller andthe point of contact 29' of the hooked portion 8 with the lower bearing surface 4 of the doubling ring should make, with the radial plane 32' passing through the said point of contact 29 of the traveller with the doubling ring, an angle 8 which is not less than, but which is preferably greater than, the angle of friction for the particular traveller and doubling ring. With this arrangement some degree of additional stability is also provided by the Wiper limb.

.It will be appreciated also that, when the traveller incorporates (as that shown in Figure 12) both a stabilizing portion 25' and a wiper portion 28, the arrangement of both these portions should preferably conform to that set, out above with reference to Figures 6 and 10, considering that the yarn 27 will be threaded through the hooked portion 7. This double arrangement has the advantage that the effective length may be increased without making the traveller, as a whole, wider than those illustrated in Figures 6 and 10.

In the modified form of traveller shown in Figure 13 there is provided a further hooked portion 25" adapted to engage the lower end of the doubling ring and to stabilise the traveller. This traveller is adapted for use on a doubling ring of the conventional shape.

The traveller shown in Figure 14 has a further hooked portion 28" adapted to contact the upper bearing surface of a round ended doubling ring and to condition this surface. These two forms of traveller may be combined as in Figure 15 where the traveller illustrated has a stabilizing portion and a conditioning portion 28".

The travellers may be formed of any suitable material, for example metal wire or a plastic. If the travellers are formed of metal wire, the wire used will preferably but not necessarily, be formed of a copper-beryllium alloy of the age-hardening type, which exhibits considerable resistance to wear whilst, in general, having a small coefficient of friction with the material of the doubling ring.

if plastic materials are used for the manufacture of the travellers it is preferred to use those plastic materials which have lower specific gravities than the metals which would be used for metal travellers for, by this means, the

travellers may be made with increased cross-sectional areas (to give increased life) without an increase in weight with relation to metal travellers. Very conveniently the travellers may be made of nylon. In any case, Whether made of metal or plastic, the travellers may have any suitable cross-sectional form and may, for example, be of circular, D-shape, or square shape in cross-section. Preferably the travellers are, where possible and especially when made of metal, formed from a single piece of the material.

Although the doubling ring shown in Figure l and other figures of the drawings, could be made of any suitable material such as steel or self-lubricating material, such as carbon or bronze,oconsiderable advantages are achieved by making the doubling ring from sintered iron which may contain a proportion of graphite.

Such a sintered iron doubling ring is formed by pressing and heat treatment, the ring being hardened and all these operations being carried out by methods known in the art of powder metallurgy, but as the ring is of a purely rectangular cross-sectional form the moulding of the same will, as hereinafter explained, be greatly facilitated and the tools required less expensive and delicate than those hitherto required in the manufacture of sintered metal doubling rings having rounded upper and lower bearing surfaces.

The composition of the ring may be, for example, iron -100% and graphite 05% by weight. Preferably the iron used is mesh iron powder which is pressed to the required shape under a pressure of between 15 to 20 tons per square inch, this pressed iron powder being heat treated in cracked ammonia gas at 1,-000 to 1,200 C. and being, after sizing, pack-carburized in a suitable carbur'izing compound at about 950 C. and quenched in water.

The sintered iron doubling ring made in this way is impregnated with lubricating oil and subsequently polished so as to give a low coefficient-of friction between the bearing surfaces of the ring and the parts of the traveller co-operating therewith without impairing the egress of oil from the pores of the doubling ring to the surface of this ring.

, By forming the doubling ring with flat upper and lower bearing surfaces substantially normal to the axis of the ring, the process of manufacturing the ring is facilitated, inter alia, by:

'(a) The avoidance of the special machining hitherto necessary to provide transversely rounded bearing surfaces at the upper and lower ends of the doubling ring;

(b) The simplification of the stacking of the rings in the heat treatment stage, the flat-ended rings being much more easily stacked than rings having rounded or chamfered bearing surfaces.

We claim:

1. A traveller for use on a vertical doubling ring having at least one square end, hooked portions on suchtraveller for engaging respectively over the upper and lower ends of the said doubling ring, and an inwardly directed bearing part furnished medially on at least one of said hooked portions and adapted, when the traveller is applied to the said doubling ring, to lie adjacent to, and to bear at some period upon, the bearing surface at a square end of the doubling ring, the said parts of the hooked portion of the traveller that adjoin and lie on the two sides of the said bearing part of such hooked portion being divergently outwardly looped thereby to maintain such parts out of contact with the said bearing surface and the corners of the adjacent square end of the doubling ring.

2. A traveller for use on a vertical doubling ring having at least one square end, hooked portions on such traveller for engaging respectively over the upper and lower ends of the said doubling ring, and an inwardly directed bearing part furnished medially on at least one of said hooked portions and adapted, when the traveller is applied to the said doubling rin to lie adjacent to, and to bear at some period upon, the bearing surface at a square end of the doubling ring, the said parts of the hooked portion of the traveller that adjoin and lie on the two sides of the said bearing part of such hooked portion being divergently outwardly looped thereby to maintain such parts out of contact with the said bear ing surface and the corners of the adjacent square end of the doubling ring, the distance between the centre of the said bearing part and (a) an intermediate part of the traveller connecting said hooked portion and (b) that extremity of the said hooked portion of the traveller remote from the said intermediate part of the traveller, being less than the radial width, but greater than half the radial width, of the square end of the doubling ring with which said bearing part is to co-operate'.

3. A traveller for use on a vertical-type doubling ring having at least one square end of which the bearing sur face is substantially flat and meets the inner and outer peripheral surface of the ring substantially at right angles, hooked portions on such traveller for engaging respectively over the upper and lower ends of said doubling ring, and a medial inwardly directed bearing part furnished between the inner and outer extremities of at least one of the said hooked portions and positioned to co operate with the bearing surface at the square end of the doubling ring, whilst an intermediate part of the traveller (connecting said hooked portions) is positioned to bear upon a peripheral surface of the doubling ring, the parts of the hooked portion of the traveller that adjoin and lie on the two sides of the said bearing part of such hooked portion of the traveller being splayed loop fashion divergently outwardly on each side of the said bearing part, whereby these parts of the said hooked portions of the traveller will be maintained clear of the inner and outer corners of the adjacent square end of the doubling ring when the traveller is in use there- 4. A traveller according to claim 3, wherein the said bearing part of a hooked portion of the traveller is, at its ring contacting part, convexly curved with respect to the square end of the doubling ring with which it is to co-operate in use.

5. A traveller according to claim 4, wherein at least one hooked portion of the traveller is of a sinuous shape with the central portion thereof constituting the said bearing part.

6. A traveller according to claim 3, wherein the bearing part of at least one hooked portion of the traveller is formed by a closed loop provided in, and extending inwardly from, its hooked portion of the traveller.

7. A traveller for use on a vertical-type doubling ring having at least one square end of which the bearing surface is substantially flat and meets the inner and outer peripheral surface of the ring substantially at right angles, hooked portions on said traveller for engagement over the upper and lower ends of the doubling ring, at least one further hooked portion also for engagement over one of the ends of the doubling ring, and a medial inwardly directed bearing part furnished, between the inner and outer extremities, of each hooked portion of the traveller which is to co-operate in use with the bearing surface at a square end of the doubling ring, said bearing part being positioned to co-operate with the said bearing surface whilst the intermediate portion of the traveller, i. e. the part connecting the first said hooked portions, is positioned to bear upon a peripheral surface of the doubling ring, the parts of the hooked portion of the traveller that adjoin and lie on the two sides of a bearing part of such hooked portion of the traveller being looped divergently outwardly on each side of such bearing part, whereby the corners of each of these hooked portions of the traveller will be maintained clear of the inner and outer corners of the adjacent square end of the doubling ring when the traveller is in use thereon.

8. A traveller according to claim 7, wherein the said &

hooked portions of the traveller and each said further hooked portion are so orientated with respect to one another and with regard to the depth of the doubling ring on which the traveller is to be used, that when the traveller is on the point of slipping on said ring, a straight line joining the point of contact of the traveller with the lower end (in the case of downwardly travelling yarn) of the doubling ring and the point of intersection of the lines of action of the forces acting through the other hooked portions of the traveller, makes, with a plane radial to the said doubling ring and passing through the said point of contact, an angle which is not less than the angle of friction.

9. A traveller for use on a vertical doubling ring having at least one square end, hooked portions on such traveller for engaging respectively over the upper and lower ends of the said doubling ring, and an inwardly directed bearing part furnished medially on at least one of said hooked portions and adapted, when the traveller is applied to the said doubling ring, to lie adjacent to, and to bear at some period upon, the bearing surface at a square end of the doubling ring, said hooked portion being looped on each side of said bearing part so as to space this portion away from the adjacent corners of the doubling ring, thereby to avoid the wearing of such portion by the corners of the ring.

10. A traveller for use on a vertical-type doubling ring of the kind having upper and lower horizontal bearing surfaces, such traveller comprising hooked upper and lower end portions; an intermediate portion connecting said hooked portions together and located and shaped to engage the inner vertical peripheral surface of the doubling ring when the hooked ends of the traveller embrace the upper and lower ends of the latter, and each said hooked portion including an inwardly directed bearing part presenting a curved aspect convex with respect to the adjacent end bearing surface of the doubling ring with which the said bearing part is adapted to engage when the traveller is in use, simultaneously to space the immediately adjoining parts of the traveller away from such bearing surface.

11. A C-type traveller for use on a vertical-type doubling ring of the kind having horizontal upper and lower bearing surfaces, such traveller comprising identical upper and lower hooked end portions; an intermediate portion connecting said hooked portions together and located and shaped to engage the inner peripheral surface of the doubling ring in use, and each said hooked portion including an inwardly directed bearing part presenting a curved aspect convex with respect to the adjacent end bearing surface of the doubling ring, said hooked portion being symmetrical about a vertical axis through said bearing part.

12. A traveller for use on a vertical-type doubling ring having at least one square end of which the bearing surface is substantially flat and meets the inner and outer peripheral surfaces of the ring substantially at right angles, hooked portions on said traveller for engagement over the upper and lower ends of the doubling ring, an intermediate portion connecting said hooked portions, at least one further hooked portion also for engagement over one of the ends of the doubling ring, and an inwardly directed bearing part furnished on each hooked portion of the traveller which is to co-operate in use with the bearing surface at the square end of the doubling ring, said hearing parts being positioned to engage with the said bearing surface whilst the intermediate portion of the traveller is positioned to bear upon the inner peripheral surface of the doubling ring, the said hooked portions being looped on each side of the said bearing parts so as to space the portions of the hooked portions that are on opposite sides of the bearing parts away from the corners of the doubling ring thereby to avoid the wearing of such hooked portions by the corners of the ring.

References Cited in the file of this patent UNITED STATES PATENTS 172,402 Dutcher Jan. 18, 1876 1,495,636 Feaster May 27, 1924 1,642,472 Wentworth Sept. 13, 1927 2,205,916 Ziegler June 25, 1940 FOREIGN PATENTS 4,241 Great Britain Mar. 1, 1884 9,583 Great Britain Aug. 12, 1885 507,963 Great Britain June 23, 1939 355,790 Germany June 18, 1921