Background ofthe Invention

Field of the Invention

This invention relates to an apparatus for wrapping flexible line around a bobbin and, more particularly, to a traveler that is mounted on a ring assembly for rotation at high speeds around the bobbin.

Background Art Heretofore, many ring and traveler mechanisms have been conceived in an attempt to achieve faster running travelers, produce less tension on yarn, increase the longevity of the traveler and ring, minimize thread breakage, and improve yarn quality. Following is a brief summary of some of this prior art and relevant limitations thereof. Much has been written about coatings that are electrically or chemically deposited upon a traveler and/or ring to reduce friction and wear. Bodnar, US Patent No. 5,086,615, Trammell et al, US Patent No. 3,387,447, and Poquette et al, US Patent No. 5,313,773, all disclose coatings of various types to achieve the aforementioned objectives. Staehli, US Patent No. 4,308,715, shows a steel ring with a coating layer. Nakano et el, US Pat. No.4,875,333, shows a ring with a ceramic coating. Of general interest is Maruta, US Patent No. 4,885,905, showing a steel ring with a carbide surface layer.

Coatings have not always proven to be a completely effective means of reducing wear and increasing operating speeds. Coatings tend to chip, exposing a softer underlying substrate. Coatings are often not applied uniformly, which may adversely affect the sliding capability ofthe coated part.

Much of the prior art suggests that the aforementioned objectives may be realized using a spinning ring rather than a fixed ring. It was presumably

thought that by reducing the relative speeds between the traveler and the spinning ring, friction between the traveler and ring could be reduced and higher speeds could be reached. However, to the knowledge ofthe inventor herein, the spinning ring technology never materialized into significant commercial usage. It is surmised that the problems associated with their use generally outweigh their benefits.

Lint and oil can migrate between the stator and rotor bearings. It is desirable to keep thread tension constant while starting and stopping the equipment. Relatively constant thread tension can be maintained with fixed ring equipment. Upon startup ofa fixed ring machine, the spindle and traveler reach operational speed much faster than they would with a spinning ring. The spinning ring generally accelerates very slowly to its operational speed. Yarn stretching may occur, ultimately resulting in thread breakage. If thread breakage occurs at an individual spinning station, repairing the thread break may require that the entire machine be stopped.

Yamaguchi, US Patent No. 5148662, and others developed a braking system to allow independent braking of a spinning ring. Yet this approach adds further complexity to the already relatively complicated equipment.

Many patents, such as Baucom et al, US Patent No. 4,270,040, and Dδnmez, US Patent Nos. 4,266,397 and 4,305,246, disclose the use of pneumatically controlled bearings to achieve low friction, high speed operation. Marzoli, US Patent No. 4,256,202, suggests the use of ball bearings to facilitate the spinning ofthe rotor at high speeds with low friction. Yarn slack buildup may be prevalent in these types of equipment. Wurmli et al, US Patent Nos. 5,331,797 and 4338775, show a spinning ring having an inclined flange. A wire traveler contacts the entire surface area of the inclined flange. The underlying teaching therein is that more surface contact area provides increased stability between ring and traveler and, therefore, less friction and wear.

A further attempt to achieve high speed, low friction operation of spinning rings through lubrication is shown in Kluttz, US Pat. No. 3,304,710, and many others to follow. The teaching is that oil be directly applied by conducting lubricant from a reservoir to against the ring by a wicking means or other conduit. McLean et al, US Pat. No. 4,768,335, and Stutz, US Pat. No. 4,334,402, are further examples of that mode of thought. Oil lubrication is undesirable in that oil tends to stain yarn or thread. Oil misting has shown to be a dirty and potentially unsafe practice to be employed around the work place.

Of general interest are Creus, US Patent No. 4,265,081, and Costales et al, US Patent No. 4,385,487, showing ring spinning drive transmissions utilizing belts and pulleys. To the knowledge ofthe inventor herein, these approaches have not achieved any significant commercial success.

Various attempts have been made to redesign travelers for long wear at high speed. The widely used "C"-shaped traveler flexes to fit over the top of an I-beam type ring rail. A spreader tool flexes the traveler arms outwards to fit over the rail. The traveler then recoils to its original form.

In a similar type of installation, the commonly used vertical bar type traveler is spread to fit over both ends ofthe inner sidewall of a ring. Kanai, US Pat. No. 4,677,817, discloses a traveler with a ceramic coating. It is the belief of the inventor herein that the coating on the traveler of Kanai's invention would crack when flexed to fit over conventional rings.

Carter, US Patent No. 4,866,923, discloses a traveler formed of polymer which is free from parting lines in the thread contact area. Thread wear can easily groove a polymer traveler, thereby creating an interrupted thread path. Eadie et al, US Patent No. 4, 132,058, and others, attempt to protect the thread grooving area with a ceramic or metal insert. This product is not known to be in widespread commercial use. Plastic travelers, even if protected in the thread grooving areas, will tend to heat up due to the extreme speed at which they travel and the vibrations to which they are subjected. The traveler may

thereby weaken. The ends may eventually spread open, causing the traveler to break off the ring.

Of general interest is Nakano, US Patent No. 4,875,333, showing a traveler made of a polyamide resin. In spite of the well known wear advantages of ceramic, known prior art shows no operational ceramic travelers because of its inability to flex, as required for assembly, and lack of memory, to assume its original shape.

Rumsey et al, U.S. Patent No. 4,354,342, discloses a ring and traveler mechanism, with the ring including two interconnected rings relatively positioned to cooperatively form a raceway in which a traveler rides. Rumsey shows an "H"- shaped traveler having two parallel legs and an interconnecting member to form an upper and lower void between the legs. The traveler is disposed between the two interconnected rings so that the rings fit into the void spaces defmed by the traveler. The void spaces are contoured to allow a snug fit between the traveler and ring. Radial or axial movement of the traveler is virtually eliminated. Rumsey apparently did not want play between the traveler and ring because he presumably thought it would increase friction and reduce the capacity for traveler speed.

Chilpan, US Patent No. 3,908,689, shows a ring having an annular groove therein. A plastic traveler is inserted into the annular groove and is confined against outward radial movement by a main body portion and against inward radial movement by a resilient anchor. Chilpan shows a traveler that is free moving with minimal contact pressure between bearing surfaces while the traveler is spinning at low speeds. However, when the traveler speed is increased, it would appear that centrifugal forces cause the main body portion of the traveler to engage against the bearing surface of the ring. In spite of having a plastic traveler to reduce friction, Chilpan still relies on lubricating ducts to keep the bearing surfaces cool. Furthermore, Chilpan could not consider using a ceramic traveler in his configuration because the ceramic material does not have

the resiliency to reassume its original shape after being deformed during assembly to fit through the annular groove.

Myers, US Patent No. 3,583,146, discloses spaced ring members defining a slot therebetween. Myers allows the ring member spacing to be altered to accommodate different size travelers in the slot. The forces exerted upon the ring by the traveler, resulting from the centrifugal forces on the ring, may cause significant wear between the contact surfaces ofthe traveler and the ring. The faster the traveler speed, the greater the centrifugal force, and the greater the wear. L. W. Schaaff, US Patent No. 2, 198,791, discloses a ring and "C-type traveler which fits over an inverted flange and within an annular groove having means to retain the traveler therewithin. This traveler/ring combination has a fulcrum point on the ring which will contact a single point on a preferably polymeric traveler at all times during its rotation. Shaaff s invention requires that his "C" ring be hooked under the lip of the traveler's retaining wall. Centrifugal force would cause the traveler to pivot outwards, resulting in additional friction that slows the traveler. There are also apparent difficulties in installing Shaaff s traveler. His "C"-type traveler could not be formed of ceramic or hardened metal because of the aforementioned problems of flexing the traveler arms around ring flanges without breaking.

Farmer, US Patent No. 791,615, discloses a ring having a back retaining wall, an inner retaining wall, an upper retaining wall, and a floor. An annular slot on the inner sidewall of the ring accepts a thread handling member therethrough. The traveler of Farmer's invention has a large mass relative to the space between the retaining walls. It is estimated that Farmer's traveler utilizes

80% of the volume of space between the retaining walls at any location on the ring. The large mass at the outer periphery of the traveler would create large centrifugal forces on the traveler. The centrifugal forces become even greater as spinning speeds increase. The tolerances between the traveler and the retaining

walls appear too tight to promote a free spinning traveler. The more contact with a retaining wall, the more the traveler slows down. As the traveler slows down relative to the spindle, thread tension increases at the spinning bobbin. Farmer diverts the thread in two different directions through the traveler. Excessive friction caused by the sliding contact of thread through a traveler in this manner could create an unwanted condition called pilling. The friction created between the retaining walls and traveler and the thread and the traveler requires that the spindle speed be reduced. Otherwise, the increased thread tension would inevitably cause thread breakage. Z. E. Booth, US Patent No. 743, 138, shows an annular ring formed of detachably mounted annular sleeves with an annular groove formed throughout the inner circumference. A traveler is mounted to a balance ball by a carrier therebetween. The traveler and balance ball have annular grooves within which the carrier's end bearings are engaged. The shank ofthe carrier passes through the annular groove, thereby positioning the traveler and the balance ball on opposite sides of converging "N"-shaped retaining walls. The traveler and balance ball are thus firmly held in contact against the raceway. Booth's traveler depends on frictional contact with both the traveler and anchor in order to prevent the tiaveler from tilting and to utilize the ball bearings to roll the traveler around the track.

Summary ofthe Invention In one form ofthe invention, an apparatus is provided for wrapping a flexible line around a bobbin located at a first central axis. The apparatus has a ring core with a wall extending around the central axis and first and second surfaces facing radially oppositely with respect to the first central axis. A first ring part and a second ring part are provided. First structure cooperates between the first ring part and at least one ofthe ring core and second ring part for mounting the first ring part for rotation relative to the ring core around the first

central axis. Second structure cooperates between the second ring part and at least one ofthe core ring and first ring part for mounting the second ring part for rotation relative to the ring core around the first central axis. A traveler is provided, with there being third structure cooperating between the traveler and at least one ofthe ring core, the first ring part, and the second ring part for maintaining the traveler in an operative position wherein the traveler is guided in an annular path around the first central axis. The traveler, in the operative position, is abuttable to each ofthe first and second ring parts.

In one form, the ring core is fixed against rotation relative to the first central axis.

The first cooperating structure may mount the first ring part for rotation relative to both the second ring part and ring core. Similarly, the second cooperating structure may mount the second ring part for rotation relative to both the first ring part and ring core. In one form, the first cooperating structure includes a first annular surface on the first ring part facing radially outwardly relative to the first central axis and a second annular surface on the ring core facing radially inwardly relative to the first central axis. The first and second annular surfaces abut and guide movement of the first ring part relative to the ring core around the first central axis.

The second cooperating structure may include a third annular surface on the ring core facing radially outwardly relative to the first central axis and a fourth annular surface on the second ring part facing radially inwardly relative to the first central axis. The third and fourth annular surfaces abut and guide movement ofthe second ring part relative to the ring core around the first central axis.

The traveler has a C-shaped body with spaced first and second legs, with the first leg engageable with the first ring part and the second leg engageable with the second ring part with the tiaveler in the operative position.

The ring core has an axially spaced top and bottom with the traveler having a C-shaped body that wraps around the top of the ring core with the traveler in the operative position. The ring core may have an exposed top surface which is engageable with the traveler to effect guiding and braking thereof. This surface may be convex.

At least one ofthe first, second, third and fourth annular surfaces may be defined by at least one rib on one ofthe first and second ring parts and ring core facing radially with respect to the first central axis.

At least one of the first, second, third and fourth annular surfaces may have a coating thereon to facilitate sliding movement ofthe one ofthe first, second, third and fourth surfaces against another ofthe first, second, third and fourth surfaces. A suitable coating is a polyamide-imide.

The core bar may have a T-shaped configuration as viewed in cross section defined by a plane extending radially of the first central axis and containing the first central axis.

In one form, the body of the traveler has an inside surface and spaced bight portions and the first ring part nests against the inside surface ofthe traveler at one ofthe spaced bight portions and the second ring part nests against the inside surface ofthe traveler at the other ofthe spaced bight portions. The first ring portion may have an L shape as viewed in cross section defmed by a plane extending radially from the first central axis and containing the first central axis, with a first leg and a second leg. The first leg projects substantially axially with respect to the first central axis and the second leg projects substantially radially inwardly from the first leg with respect to the first central axis and nests against the inside surface ofthe traveler at the one ofthe spaced bight portions.

The second ring part may have an L shape as viewed in cross section defined by a plane extending radially from the first central axis and containing the first central axis with a third leg and a fourth leg. The third leg projects

substantially axially with respect to the first central axis and the fourth leg projects substantially radially outwardly from the third leg with respect to the first central axis and nests against the inside surface ofthe traveler at the other of the spaced bight portions. The traveler body may be defined by a formed, flat strip of material. The body has first and second legs each having a free end. At least one ofthe free ends ofthe first and second legs on the body is offset to define a substantially flat surface residing in a plane that is substantially parallel to the first central axis. In one form, at least one ofthe free leg ends is offset to define a substantially flat surface residing in a plane that is substantially parallel to the first central axis.

In another form, at least one of the free leg ends is offset and has a surface substantially conforming to a surface on one ofthe first and second ring parts to which the traveller surface is abuttable. In another form, at least one ofthe free leg ends is offset and has first and second surfaces facing radially with respect to the first central axis and together defining a V shape. This V shape can open either radially inwardly or radially outwardly with respect to the first central axis.

The ring core may have a coating on at least a part thereof that contacts at least one ofthe first and second ring parts. A suitable coating for this purpose is sold commercially under the trademark TEFLON®.

In another form of the invention, an apparatus is provided for wrapping a flexible line around a bobbin located at a first central axis. The apparatus has a stationary ring core having a wall extending around the central axis, a first ring part, structure cooperating between the first ring part and ring core for guiding relative movement of the first ring part relative to the ring core around the first central axis, a traveler having a body with C shape, and first structure cooperating between the traveler and first ring part and ring core for guiding the

traveler directly against the ring core and first ring part in an annular path around the first central axis with the traveler in an operative position.

A second ring part can be provided with structure cooperating between the second ring part and ring core for guiding movement ofthe second ring part relative to the ring core, with there being second structure cooperating between the traveler and second ring pait for guiding movement ofthe traveler relative to the ring core in conjunction with the first cooperating structure.

In one form, the ring has a T shape as viewed in cross section defined by a plane extending radially from the first central axis and containing the first central axis, with there being a stem extending axially with respect to the first central axis and a transverse cross bar. The first cooperating structure includes a surface on the cross bar ofthe ring core.

The surface on the cross bar can be convex.

The stem and cross bar defined L-shaped first and second seats as viewed in cross section defined by a plane extending radially from the first central axis and containing the first central axis. The first and second ring parts each have an L shape as viewed through the same cross section and nest, one each in the L- shaped first and second seats.

The traveler body may have space free ends with one of the free ends engageable with the first ring part and the other of the free ends engageable with the second ring part with the traveler in the operative position.

The first and second ring parts may be made partially or wholly from a polymer material.

The apparatus may further include a base having a receptacle, with structure cooperating between the base, ring core, and first and second ring parts to allow the ring core to be directed axially relative to the first central axis between the first and second rings into the receptacle base to maintain the ring core and first and second ring parts in operative relationship.

Brief Description ofthe Drawings

Fig. 1 is a fragmentary perspective view of an apparatus for wrapping a flexible line, according to the present invention, in operative relationship with a rotating bobbin on which the line is wound; Fig. 2 is an enlarged, fragmentary, cross-sectional view of one form of ring assembly and traveler as shown in Fig. 1 and in operative relationship;

Fig. 3 is a view as in Fig. 2 showing a modified form of ring assembly according to the present invention;

Fig. 4 is a fragmentary, perspective view of another modified form of ring assembly and traveler according to the present invention;

Fig. 5 is a cross-sectional view of the ring assembly and traveler taken along line 5-5 of Fig. 4;

Fig. 6 is a view as in Fig. 5 showing the traveler of Fig. 5 in different orientations as occur normally in use; Fig. 7 is a view as in Figs. 5 and 6 of a still further modified form of traveler, according to the present invention; and

Fig. 8 is a fragmentary perspective view of a still further modified form of ring and traveler according to the present invention.

Detailed Description of the Drawings In Figs. 1 and 2, one foim of inventive system is shown at 10 for wrapping a flexible line 12 around a cylindrical bobbin 14, which is mounted upon a spindle 16 at a central axis 18. Rotation is imparted to the spindle 16 by a means, shown schematically at 20 in Fig. 1.

The present invention is directed to a ring assembly at 22 and a traveler 24 which moves guidingly in an annular path on the ring assembly 22 around the central axis 18 to draw the flexible line 12 from a bulk supply/source 26 thereof in a wrapping motion around the bobbin 14. The ring assembly 22 is supported on a ring rail 28. Means, shown schematically at 30, reciprocates the ring rail 28

and ring assembly 22 thereon axially relative to the bobbin 14 to thereby cause an even distribution of the flexible line 12 thereon as the bobbin 14 rotates.

The general overall operation ofthe apparatus 10 is well known in the art. Briefly, the flexible line 12, normally in the form of a yarn/thread, is directed from the supply/source 26, around the traveler 24 and around the rotating bobbin

14. As the bobbin 14 rotates, the traveler 24 is drawn in a trailing, annular path around the ring assembly 22.

The details ofthe first form of inventive ring assembly 22 and traveler 24 are seen clearly in Fig. 2. The ring assembly 22 includes an annular base 31 that is fixed to the ring rail 28. The base 31 defines a receptacle 32 for a ring core 34.

The ring core 34 has a T-shaped cross sectional configuration with a stem 36 and a cross bar 38.

A first ring part 40 has an annular, outwardly facing surface 41 that abuts to a radially inwardly facing, annular surface 42 on the ring core 34 and is 5 thereby guided in rotation relative to the ring core 34 around the central axis 18.

More specifically, the first ring part 40 has an L-shaped configuration in cross section, with a first, vertical leg 44 extending substantially parallel to the central axis 18, and a transverse second leg 46 projecting substantially radially from the leg 44. The leg 46 has an offset free end 48. o The first ring part 40 is configured to nest in a seat 50 defined by transverse surfaces 52, 54 at the juncture of the stem 36 and cross bar 38. With the first ring part 40 nested in the seat 50, the offset free end 48 of the ring part 40 wraps around the radially inwardmost end 56 ofthe cross bar 38. In this position, the ring part 40 is confined in vertical movement between the surface 5 54 on the cross bar 38 and an upwardly facing surface 58 on the base 31.

Optional, annular ribs 62 project from the ring surface 41 and directly abut the ring core surface 42. This reduces the contact area between the ring part 40 and ring core 34 from the contact area that would result in the absence of the ribs 62. The number, width, size, and shape ofthe ribs 62 is a design

consideration. For example, it is not necessary that the ribs 62 extend continuously along the peripheral extent ofthe surface 41. Alternatively, discrete dimples could be provided on the surface 41 to perform the same function. Similar ribs 64 are provided on the leg 46 on the ring part 40 to abut to the surface 54 on the cross bar 38 and serve the same function as the ribs 62.

A second ring part 66, having a larger diameter than the ring part 40, is assembled on the outside ofthe ring core 34. The ring part 66 likewise has an L- shaped configuration in cross section, with a vertically/axially extending leg 68 and a transverse, horizontally/radially extending leg 70 thereon and having an offset free end 72.

The ring part 66 nests in a seat 73, corresponding to the seat 50 and defined by a radially outwardly facing surface 74 on the stem 36 of the ring core 34 and the downwardly facing suiface 76 on the cross bar 38 of the ring core 34. The ring part 66 is captive between the surface 76 and the upwardly facing surface 58 on the base 31. The leg 70 extends under the cross bar surface 76 and has its end 72 offset to extend conformingly around the radially outermost end 78 ofthe cross bar 38.

The leg 68 has an annular surface 80 to abut to and be guided against the surface 74 on the ring core 34 to guide the second ring part 66 against and relative to the ring core 34 around the central axis 18. Optional ribs 82, correspondingly configured to the ribs 60, previously described, may define the actual contact surface on the leg 68. Similar ribs 83 may be provided on the upwardly facing surface 84 on the leg 70. To place the ring assembly 22 in its operative position, the ring parts 40,

66 are placed in concentric relationship with the bottom edges 86, 88 supported upon the base surface 58. The stem 36 on the ring rail 28 is then directed downwardly between the ring parts 40, 66 and into the receptacle 32 and appropriately anchored, as by an adhesive or by other means well known to those

skilled in the art. In a preferred form, the base 31 is crimped to retain the ring core 34.

Once the parts are assembled, the ring parts 40, 66 are freely rotatable relative to each other and the ring core 34 around the central axis 18. Movement ofthe ring parts 40, 66 relative to the ring core 34 is imparted by the traveler 24 with the system 10 in operation.

The traveler 24 has a C-shaped body 90 with an inside surface 92 and an outside surface 94. In a preferred form, the traveler 24 is formed from a substantially rectangular sheet of flat material with a curved upper wall 95 blending into spaced bight portions 96, 98.

With the traveler 24 in its operative position, the free end 48 ofthe first ring part 46 nests in a receptacle 100 defmed by the inside surface 92 at the bight portion 96, with the offset end 72 ofthe leg 70 nesting in a receptacle 102 defmed by the inside surface 92 ofthe traveler at the bight portion 98. The traveler 24 is initially flattened out to enlarge the opening between the free edges/ends 104, 106 of the traveler 24 sufficiently to allow direction of the traveler 24 over the upper end of the subassembly 107 consists ofthe first and second ring parts 40, 66 and ring core 34. The traveler body 90 can then be compressed to seat the edges 104, 106 in close proximity to the inwardly facing surface 108 on the first ring part 40 and the radially outwardly facing surface 110 on the second ring part 66.

It is intended that the traveler 24 be sufficiently loosely connected to the subassembly 107 that the traveler 24 can be smoothly guided around the subassembly 107 without any significant resistance. However, in operation, the flexible line 12 is directed under the traveler 24, as shown in Fig. 2. In operation, the traveler, drawn by the line 12, is canted, as a result of which one or both of the edges 104, 106 press against one of the surfaces 108, 110 on the ring parts 40, 66, respectively. As this occurs, the ring part(s) 40, 66 so engaged by the traveler edge 104, 106 follows the traveler 24.

The significance of this is that in the absence of the moving ring parts 40, 66, a substantially greater amount of friction would be developed between the traveler 24 and a guiding stationary ring, particularly at the high operating speeds at which the traveler 24 is required to operate. This constant action ofthe traveler 24 against the ring parts 40, 66 would ultimately lead to excessive heat generation and potentially to the damage and/or failure ofthe traveler 24 and/or ring parts 40, 66.

With the inventive structure, those points at which the traveler 24 contacts the ring parts 40, 66, and which would otherwise be prone to substantial wear are protected. The affected ring part 40, 66, i.e. that against which the traveler edge

104, 106 presses, follows the traveler 24 so that the relative rotational velocity between the traveler 24 and ring part(s) 40, 66 is reduced significantly, or to zero. That is, the ring parts 40, 66 in effect stick to the traveler 24. As this latter condition occurs, the higher speed relative movement is between the ring parts 40, 66 and the ring core 34. Since the area of the coacting surfaces on the ring core 34 and ring parts 40, 66 is substantial, significantly less wear occurs on the ring parts 40, 66 than would occur by having the traveler 24 guided in movement relative to a stationary guiding ring.

In normal use, it is contemplated that the first ring part 40 and/or second o ring part 66 will rotate at a slower speed than the traveler 24. It is desirable that the traveler 24 draw the first and/or second ring parts 40, 66 so that the traveler 24 does not rotate at any significant speed relative to the first or second parts 40, 66 at the highest traveler speed.

Depending upon the degree of canting of the traveler 24, the side edges 5 112, 113 thereon may abut and guide along a top surface 114 of the ring core

34. Aside from the guiding function, the coaction between the traveler 24 and this surface 114 causes braking of the traveler 24 when the system 10 is slowed or shut down.

In Fig. 3, a modified form of ring assembly is shown at 122. The ring assembly 122 differs primarily in the configuration of the ring portion 40', corresponding to the ring portion 40 in the prior embodiment, the configuration ofthe ring portion 66', corresponding to the ring portion 66 in the prior embodiment, and the top region at 124 ofthe ring core 34', coπesponding to the ring core 34 in the prior embodiment. In that the overall function ofthe ring assembly 122 in Fig. 3 is the same as that 22 in Fig. 2, the description herein will be limited principally to the structural differences.

The ring portion 40' has an L-shaped configuration in cross section with a vertically/axially extending leg 126 and a transversely/horizontally extending leg 128. The upper, and radially outwardly facing surfaces 130, 132, respectively, are substantially flat and at right angles to each other as opposed to the multiple curves provided in the ring part 40. The leg 128 terminates at a rounded edge 134 at its radially innermost extent. The edge 134 nests in a right angle seat 135 defined by transverse, flat surfaces 138, 140 on the ring core 34'.

The free end 142 of the leg 128 does not wrap around the ring core 34' as in the prior embodiment.

The ring part 66' is constructed in the same manner as the ring part 40' and cooperates with the ring core 34' in the same manner. The ring core 34' has an exposed, upper surface 144 which acts against the traveler edges 112, 113 to both guide and brake movement ofthe traveler 24. The surface 144 has a convex curvature so that substantially only the apex 146 of the surface 144 contacts the traveler 24 in use.

The principle of operation ofthe ring assembly 122 is the same as for the ring assembly 22 in the prior embodiment.

In one prefeπed form, the ring parts 40, 66, 40' 66' are made from a plastic material. A suitable material for this purpose is polyamide-imide which is commercially available.

The ring cores 34, 34' are preferably made from metal, such as steel, with a low friction coating thereon, such as those sold commercially under the trademarks TEFLON® or TORLON™.

In Figs. 4-6, a modified form of traveler 24' is shown in operative relationship with a ring assembly at 146, having a ring core 34' and base 31 identical to those same elements in Fig. 3. The system 146 has inner and outer ring portions 148, 150, similar to the ring portions 40', 66' in Fig. 3, with the exception that the inner ring portion 148 defines a squared, inside seat 152, at the juncture of vertical and horizontal legs 154, 156, respectively, and the outer ring portion 150 defines a squared outside seat 158 at the juncture of the vertical and horizontal legs 160, 162.

The traveler 24' has spaced inner and outer legs 164, 166. The inner leg 164 has an offset free end 168 defining two flat surfaces 170, 172 which cooperatively define a V shape and are separately abuttable to an inwardly facing, annular surface 174 on the vertical leg 154 of the inner ring portion 148.

The outer leg 166 has an offset free end 176 with a curved surface 178 that is abuttable to an outwardly facing, annular surface 180 on the vertical leg 160 ofthe outer ring portion 150.

With the traveler 24' in a normal position, as shown in Fig. 5, the vertical leg 154 on the inner ring portion 148, the ring core 34', and the vertical leg 160 on the outer ring portion 150 are captive between the curved surface 178 on the outer ring leg 166 and an apex 182 on the offset leg end 168 at the juncture ofthe flat surfaces 170, 172.

With the line 12 drawing the traveler 24' in one direction around the bobbin, the traveler 24' moves from the solid line position in Figs. 5 and 6 to a canted position as shown in phantom lines in Fig. 6. In transition between the solid and phantom line positions, the curved surface 178 rocks against the surface 180, which brings the surface 172 on the leg end 168 against the ring surface 174. The surface 172 is preferably either flat, as shown in Fig. 5, or

slightly curved to conform substantially to the curvature ofthe surface 174 on the ring portion 148.

Canting in the opposite direction brings the surface 170 on the leg end 168 into substantially facial engagement with the surface 174 on the inner ring portion 148.

The above anangement accounts for a potentially larger contact area between the traveler 24' and inner and outer ring portions 148, 150 than can be accomplished with the traveler 24 as shown in Figs. 1-3. As a result, wear, resulting from movement ofthe traveler 24' relative to the inner and outer ring portions 148, 150 is reduced. This anangement also provides further stability to the traveler 24' as it moves around the bobbin.

The invention further contemplates traveler 24", as shown in Fig. 7, wherein an offset end 184 on a leg 186 has a surface 188 conforming substantially to the inner ring surface 174. The traveler 24" can have an outer leg (not shown) with an offset end that is conforming to the surface 180 ofthe outer ring portion 148.

This latter anangement does not allow a significant repositioning ofthe traveler 24' relative to the ring assembly but effects a more positive guiding of the traveler 24". A further modified form of the inventive system is shown at 200. The system 200 includes a base 31 with a receptacle 32 therein, and a C-shaped traveler 24, as shown in Figs. 1 and 2.

The system 200 includes inner and outer ring parts 202,204, respectively, between which a ring core 205 is located. The ring parts 202,204 have upper ends 206,208, which cooperate with the traveler 24 as in the embodiments previously described.

The principal distinction with the system 200 resides in the relationship between the bottom ends 210,212 of the rings parts 202,204, and the cooperation between the bottom ends 210,212 and the ring core 205 and base 31. More

specifically, the bottom end of the inner ring part 202 has an outturned flange 214, with the bottom end 212 ofthe ring part 204 having a coπesponding inturned flange 216. With the ring core 205 directed downwardly between the inner and outer ring parts 202,204, a downwardly facing surface 218 on the ring core 205 captively holds the flange 214 against the base 31, with a like surface

220 captively holding the flange 216 against the base 31.

The basic operation of the system 200 is similar to the embodiments, previously described.

The invention also contemplates that additional moving rings could be used to provide an additional degree of relative movement between parts. For example, in Fig. 8, a ring 222 is shown in phantom inside of the inner ring 202. As the traveler 24 presses against the ring 222, the ring 222 is caused to follow movement of the traveler 24 while slipping. Eventually the speed of the ring 222 is imparted to the inner ring 202. A similar ring 224 is shown in phantom outside of the outer ring 204. Any number of additional rings could be provided consistent with the invention.

The foregoing disclosure of specific embodiments is intended to be illustrative of the broad concepts comprehended by the invention.