Reusable winding tube

An end cap is releasably mounted on the end of a cylindrical hollow tube to form a reusable cylindrical yarn carrier or winding tube which carries a filamentary or fibrous yarn thereon. The confronting ends of the hollow tube and end cap define a peripheral groove therebetween. A minor portion of the peripheral groove is relatively narrow (locking portion), while the remaining major portion of the groove is relatively wider (lead-in portion). When the yarn carrier has been emptied, the end cap is separated from the hollow tube and the residual fibers or filaments vacuumed or stripped away.

BACKGROUND AND SUMMARY OF THE PRESENT INVENTION 
The present invention is directed to winding tubes, and more particularly 
to a reusable winding tube in which the fibers or filaments are more 
easily removed from the peripheral groove which carries the transfer bunch 
once the package has been emptied. 
In conventional automatic winding operations, yarn is wound onto a 
cylindrical paper tube. One end of the paper tube includes a peripheral 
groove cut into the surface thereof. The peripheral groove is divided into 
two arcuate portions. The greater arcuate portion (approximately 
270.degree.) is wider and referred to as the lead-in portion, while the 
smaller (approximately 90.degree.) arcuate portion (locking portion) is 
narrower and locks one or more of the initial strands of yarn therein 
during the initial few turns of the automatic winding operation. These 
strands are hereinafter and commonly referred to as the "transfer bunch." 
The completed yarn package is removed from the winding machine, and stored 
or shipped for further processing. During the further processing, the yarn 
is then removed from the yarn carrier. 
When the yarn is removed from the package, the last few strands of the 
transfer bunch remain in the lead-in and locking portions of the groove. 
Because of the construction of the paper tubes, it is very difficult to 
remove these remaining strands of fibrous or filamentary material from the 
grooves. Previous attempts to remove these strands have included vacuum 
stripping, cutting of the strands, or a combination of both. Neither 
technique is satisfactory, because vacuum stripping simply does not remove 
all the fibrous or filamentary material. Cutting the bunch generally 
results in damage to the surface of the tube making it unsuitable for 
further use. Such damage occurs when the laminates of the paper tube are 
niched, cut, or otherwise interrupted. Use at high speeds then tends to 
cause delamination. 
As a result, paper winding tubes are generally not reusable. There have 
been some attempts to reuse the tubes by providing the transfer grooves at 
each end of the tube, so that the tube can be reused at least once. 
However, often the tube is otherwise damaged during the automatic doffing 
and emplacement operations which substantially eliminates the reuse of the 
paper tubes. Conventional paper tubes are relatively expensive (50.cent. 
to $1.50 apiece) and hundreds of thousands per year are used by typical 
yarn manufacturers. Thus the cost of non-reusable yarn carriers is 
extremely high. 
Merely the replacement of paper tubes with a stronger material such as a 
polymeric material or aluminum is not an obvious solution. First the 
transfer groove cannot satisfactorily be molded or machined in the wall of 
a polymeric or metallic tube. Secondly merely a change of material does 
not solve the problems created by the necessity to clean the starting 
bunch groove, as it is still not easy to vacuum the groove, and utilizing 
a knife will still damage the surface of the tube so that it cannot be 
reused. While the use of polymeric material or metallic material such as 
aluminum is a first step toward an improved tube, it has been found that 
some technique for the cleaning of the transfer groove must be provided in 
order to achieve a reusable winding tube. 
Examples in the prior art of separable yarn carriers are illustrated in the 
U.S. Pat. Nos. to Chaffin No. 1,991,880; Moss No. 2,837,297; and Underwood 
No. 3,971,526. However, none of these yarn carriers are for automatic 
winding operations or for the purpose of solving the problem of removing 
residual fibers and filaments from a transfer bunch. 
In the broadest aspect of the present invention then, the tube is made 
reusable by the combination of selecting an appropriate material and a 
unique fabrication technique. The tube is formed of a polymeric or 
metallic material in two separable parts, i.e. the main hollow tube 
portion and a removable end cap. A peripheral groove of unique shape is 
formed between confronting walls of the end cap and hollow tube to receive 
the transfer bunch during the automatic winding operation. After the yarn 
package is emptied the end cap is removed or partially removed from the 
hollow tube portion, the fibers or filaments vacuumed or stripped away, 
and the end cap replaced. The yarn carrier is then ready for reuse. 
In its more specific aspects the reusable winding carrier of the present 
invention includes a hollow tube having an outer, substantially 
cylindrical surface adapted to carry a filamentary or fibrous yarn 
thereon. The end cap includes an outer substantially cylindrical surface 
generally of the same radius as the outer surface of the hollow tube. The 
end cap and hollow tube include mating threads or other releasable 
attachment means for releasably mounting the end cap on at least one end 
of the hollow tube. It is possible that both ends of the hollow tube may 
include releasable end caps to make the winding tube last even longer. 
A peripheral groove is formed between the hollow tube and end cap 
encircling the yarn carrier. The groove is formed with a relatively narrow 
locking portion extending around a minor portion (approximately 
90.degree.) of the periphery of the tube and a relatively wider lead-in 
portion extending around the remaining major of the periphery. The lead-in 
portion guides the first few turns of the transfer bunch into the locking 
groove. The wider and narrower portions of the peripheral groove are 
formed by molding recesses into or chamfering the confronting walls of the 
hollow tube and/or end cap during the fabrication of the components. 
The construction of the present invention combines the benefits of overall 
economy for the plant; facilitates cleaning of the transfer groove; allows 
replacement or refurbishment of worn or damaged portions of the winding 
tube assembly; and minimizes the chance of damage to the tube during 
shipment and use. 
It is therefore an object of the present invention to provide a reusable 
yarn carrier or winding tube by facilitating the cleaning of the transfer 
groove. 
It is another object of the present invention to provide a winding tube of 
the type described in which the end portion of the winding tube is 
removable from the main body portion.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
Turning now to the drawings, and particularly to FIG. 1, there is 
illustrated a yarn package formed in accordance with conventional 
automatic winding techniques. The yarn package includes a winding tube WT 
about which thousands of turns of yarn Y are wrapped. The winding tube WT 
is formed of at least two parts, i.e. the cylindrical hollow tube 10 and 
at least one end cap 20. A groove extending around the periphery is formed 
between the hollow tube 10 and releasable end cap 20. As the yarn package 
is initially formed, a relatively small number of turns of the yarn are 
guided into the groove where they are locked and form the transfer bunch. 
The length of yarn extending between the transfer bunch and the yarn 
package Y is referred hereinafter as the transfer tail TT. 
An empty winding tube WT is initially emplaced on the spindle (not shown) 
of a winding machine ready to have yarn wound thereupon. During the 
automatic winding operation of polyester or any other extruded polymeric 
yarn thereon, a vacuum hose is receiving the continuous extrusion of 
polyester or other polymeric yarn filament through a spinneret awaiting 
the emplacement of the winding tube. The vacuum hose is then held near the 
bottom periphery of the winding tube WT while a hand-held wire instrument 
is used by the operator to lift or move the yarn filament into contact 
with the peripheral groove 42. As the yarn is guided into the peripheral 
groove 42 it latches up and breaks from the remainder of the yarn being 
carried away by the vacuum hose. After the break occurs, rotation of the 
winding tube causes a few turns to form a transfer bunch in the peripheral 
groove 42. The transfer bunch includes approximately one hundred or less 
turns. Formation of the transfer bunch functions to lock the leading end 
of the yarn tail as well as to maintain the "off-spec" yarn out of the 
yarn package while the speed of the yarn being extruded and the rotation 
of the tube is stabilized. After the transfer bunch is completed, the 
winder goes into a normal wind cycle with the yarn being wrapped around 
the main body of the hollow tube 10. Once the yarn package is emptied, the 
winding tube WT must either be discarded, or else the groove in which the 
transfer bunch is wound must be cleaned of remaining fibers. While in 
conventional winding techniques, for all practical purposes the groove of 
a paper tube cannot be cleaned, in the present invention such cleaning is 
made possible and even facilitated. 
Thus, in the present invention, once the winding tube WT is emptied, the 
end cap 20 is loosened from the hollow tube 10, whereupon the remaining 
fragments, filaments, or fibers of the transfer bunch may be easily 
vacuumed or stripped away. The end cap 20 is then tightened, and the yarn 
carrier WT is ready for reuse. 
Turning now to FIG. 2 there is illustrated an empty winding tube WT. A 
hollow cylindrical tube 10 is provided with a releasable end cap 20 on one 
end thereof. The periphery of tube 10 and end cap 20 are substantially 
coextensive. As illustrated in FIG. 2, a second end cap 20 may be 
releasably attached to the opposite end, in which case the life expectancy 
of the tube may be extended, and either end of the tube may serve to 
accumulate the transfer bunch. However, it is felt that a quite 
satisfactory, long lasting winding tube WT can be fabricated which 
includes the end cap 20 on one end alone. Both the hollow tube 10 and the 
end cap(s) 20 are formed of a more permanent material such as polymers 
selected from the group containing polycarbonate, PBT, PVC, ABS, 
polytetraphthalate, glass filled polymers, and carbon filled polymers. The 
tubes may even be formed of aluminum, magnesium, or some other lightweight 
metallic material. One side advantage of the present invention is that 
paper tubes are limited as to the spindle speed. It is anticipated that 
polymeric or aluminum winding tubes may be operated at much higher spindle 
speeds thus leading to other economies for the yarn manufacturer. 
Looking at FIGS. 3 and 4, the relationship between the end cap 20 and 
hollow tube 10 is best shown as a result of the enlarged illustrations. 
The hollow tube 10 includes a marginal or terminal portion 12 having 
reduced wall thickness and internal threads 14 extending peripherally 
around the interior wall thereof. Hollow tube 10 terminates in an end wall 
16 which is the terminal end of marginal portion 12. A tapered or 
chamfered surface 18 joins the outer periphery of hollow tube 10 and the 
end wall 16 to guide yarn being wrapped around hollow tube 10 in the area 
of the end portion thereof inwardly toward the peripheral grooves 40,42. 
The end cap 20 includes an axially extending end or nose 22 of reduced wall 
thickness and having outer threads 24 around the periphery thereof which 
mate with and engage the inner threads 14 of hollow tube 10. The mating 
threads 14,24 form a means for releasably mounting the end cap 20 onto the 
hollow tube 10. Alternate mounting means might include snap fits, bayonet 
tabs, male and/or female tapered marginal portions tapered, and the like, 
it being understood that the mating threads 14,24 are representative 
thereof. Immediately adjacent the base of threads 24 on end cap 20 is a 
radially extending peripheral rim 26, which forms a stop means against 
which the end wall 16 of the hollow tube 10 engages as the end cap is 
mounted on the hollow tube 10. The marginal or end portion 12 of hollow 
tube 10 is longer than the nose 22 of the end cap 20, so that the end wall 
16 will engage peripheral rim 26 prior to the time the terminal wall 23 of 
the end cap 20 engages the corresponding portion of hollow tube 10. 
A shoulder 28 extends around approximately three-fourths of the periphery 
of the end cap 20 to guide yarn into the groove between wall 30 and the 
end wall 16 (approximately 270.degree.) and separates the peripheral rim 
26 from a second or groove forming wall 30. The shoulder 28 maintains a 
separation (approximately 0.22 inches) between the end wall 16 of hollow 
tube 10 and the second groove forming wall 30 which separation is 
substantially greater than the diameter of the yarn being wound thereon. A 
bevel surface 32 (approximately 45.degree.) angles outwardly from the 
groove forming wall 30 toward the outer periphery of the end cap 20. 
Finally a slight chamfer 34 connects the outer periphery of end cap 20 
with the bevel surface 32. 
In the remaining one-fourth (approximately 90.degree.) of the periphery of 
the end cap, the shoulder 28 and groove forming wall 30 are replaced by 
the slightly angled peripheral rim 36. Rim 36 does not extend radially, 
rather is tapered away from an imaginary radius by an angle of 
approximately 5.degree. 30 min. Again the second rim 36 is connected to 
the outer periphery of end cap 20 by a chamfered surface 34. 
Thus formed, there is a peripheral groove means formed between the 
confronting walls of the hollow tube and the end cap which encircles the 
yarn carrier. The groove means includes first a relatively wide lead-in 
portion 40 which is formed by shoulder 28 and which extends approximately 
270.degree. around the periphery of the winding tube WT. Secondly a 
relatively narrow locking portion 42 is formed between the end wall 16 of 
hollow tube 10 and the second peripheral rim 36 of end cap 26. So 
arranged, the yarns of the transfer bunch are directed toward the lead-in 
groove 40 and into the locking groove 42 as the winding tube is rotated. 
As can be easily seen from FIGS. 3 and 4, when the yarn package is emptied, 
yarn fibers and filaments tend to remain in the lead-in groove 40 and the 
locking groove 42. Such yarn ends cannot be vacuumed or stripped away in 
conventional, integrally formed paper tubes. However, the present 
construction allows the operator to unscrew the end cap slightly, 
whereupon the fibers and filaments are released and can be easily removed 
by suction or other stripping techniques. 
As suggested earlier, the separable end cap and peripheral groove 
configuration may appear at both ends of the winding tube, if desired. 
Also, the hollow tube and/or end cap may be formed of polymeric or 
metallic material to increase the longevity thereof. 
While the invention has been described in detail hereinabove, it is obvious 
that various changes and modifications might be made without departing 
from the scope of the invention which is set forth in the accompanying 
claims, in which: