US 3628747 A
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United States Patent  Inventor 2,883,124 4/1959 Atwood etal. 242/1 18.3 o 3,107,067 10/ 1963 Atwood et a1. 242/1 18.3 Qfs- 23 1 FOREIGN PATENTS 5] Fauna 775,174 10/1934 France 242/1183 [731 Anita co-flau Nu m In 226,683 1/1925 Great Britain.... 242/1184 Mul. Ah 647,546 10/1962 Italy 242111831 630,039 10/1962 Italy 242/1 18.31
Primary Examiner-George F. Mautz I 1 m Attorney-Davis, 110m, Faithful] & 11 m (L a: ABSTRACT: A textile pirn upon which filamentlry material is [so mum ..242/11s.31 "Phmhk H 8.32 I 83 8 prevent damage to the nose end of the pin, to cover previous damage, and to aid in the runofl of the filament over the nose  References Cited UNITED STATES PATENTS 2.714.812 8/1955 Leath et a1 242/128 X I0 I I l6 I 1 I I l 1 7 David Baketvell PlRN CAP This invention is concerned with a tubularpirn on which filamentary material of indefinite length such as textile yarn, thread, roving, tow, cord, twine, or the like is wound for transportation and dispensing.
A pirn is a hollow metal cylinder typically 2 inches in diameter and somewhat more than a foot in length. To provide a suitable surface, the metal cylinder may be provided with an external shrink fitted phenolic plastic sleeve. The plastic sleeve may be provided with a surface finish of fine circumferential grooves to reduce axial slipping of the yarn on the pirn. The plastic sleeve extends around one end of the cylinder to provide a smoothly rounded surface at that end. This end is commonly called the nose and is the end of the pirn from which the yarn is drawn in a direction generally parallel to the pirn axis as the yarn is used. The other end of the pirn is commonly called the tail and is the end by which the pirn is held when the pirn bearing a yarn supply is placed in the machine which uses the yarn.
When the yarn supply has been exhausted from a pirn, the empty pirn is removed from the yarn using machine and is replaced by another pirn having a new supply of yarn. The
empty pirn is returned to the yarn manufacturer who winds a.
new supply of yarn on the pirn. The plastic covering on the nose of the pirn must be free of nicks, dents, or abrasions because such irregularities would interfere with the feeding of the yarn as the yarn is run off or drawn over the nose of the pirn during use.
The nose of the pirn is particularly prone to impact damage during storage and return shipment of the empty pirns to the yarn manufacturer because the empty pirn has no yarn to serve as a cushion. The ends of empty pirns are more exposed to impact damage than is the cylindrical surface. While damage to the tail of the pirn is not particularly significant, damage to the nose affects the freedom with which the yarn runs across the nose as the yarn is drawn from the pirn during use. Damage to the nose of the pirn has heretofore necessitated removal and replacement of the shrink fitted plastic sleeve.
The present invention prevents damage to the pirn nose, permits the continued use of pirns having previously damaged noses, and permits easy replacement of a damaged nose portion by providing a readily replaceable cap ring which serves as the nose of the pirn. The replaceable cap ring improves the uniformity of runoff characteristics over pirns not provided with the ring of the present invention.
The drawing is a view partially in section of a pirn fitted with the cap ring of the present invention.
Referring now to the drawing, the pirn comprises a hollow metal cylinder having a plastic end plug 12 frictionally held in the nose end of the pirn. End plug 12 is provided with an outer circumferential rounded edge 14. A plastic sleeve 16 is shrink fitted about the cylindrical exterior of the pirn tube 10 and about the nose end of the pirn tube and the circumferential edge 14 of the end plug 12. The resulting radius of the end of the plastic sleeve 16 constitutes the surface of the nose of the pirn. it is this surface which is prone to damage that affects the usefulness of the pirn.
The present invention adds to this conventional pirn construction a plastic cap ring 20 which fits over the nose portion of the pirn and is retained thereon by friction. The ring 20 may be molded from flexible plastic such as polyethylene thereby rendering the ring resistant to permanent impact damage in the form of nicks or dents. Alternatively, the ring may be molded of a phenolic similar to that employed in the sleeve 16. In either case, the ring20 is easily replaced when damaged. The cap ring 20 may be molded in identifying colors which are indicative of the nature of the yarn supplied on the pirn.
The exterior shape of the ring 20 includes a smooth rounded portion 21 against which the yarn bears during runoff. A tapered conical surface 22 is merged with the rounded surface 21 at the upper end and with the cylindrical surface of the pirn at the end remote from the nose to extend the protection afforded by the ring 20 over a considerable ortion of the cylindrical surface near the nose of the pirn. he taper of surface 22 insures that the yarn being run off has only minimal contact with the ring at the rounded surface 21 to reduce friction.
The ring 20 stands proud of the cylindrical exterior surface of the pirn by having an outer diameter substantially greater than that of the cylinder to preserve the desirable minimum of contact as the yarn supply is exhausted to the last windings in contact with the pirn surface. This greater diameter prevents the yarn from being drawn along the cylindrical surface of the pirn to thereby maintain substantially unifonn the frictionally drag of the yarn as it runs off the pirn.
The ring 20 can be used on pirns having previously damaged nose portions to thereby render them serviceable without the the need to replace the plastic sleeve 16. Further, the ring 20 tends to reduce pirn damage because it reduces the contact among empty pirns during storage and shipment. Empty pirns provided with the ring of the present invention can be stacked for storage and shipment with adjacent pirns reversed in respect to each other such that the rings 20 completely prevent contact of adjacent cylindrical surfaces. Any damage which may occur to the nose of the pirn occurs on the surface of the ring 20 rather than on the body of the pirn proper. The ring is readily replaceable. When the ring 20 is made of flexible plastic, permanent damage to the nose surface of the pirn is greatly reduced.
1. A pirn for receiving, storing and delivering a wound supply of filamentary material comprising; a hollow tube having a hard nonmetalic layer extending substantially over the entire exterior surface of and extending over the nose end of the tube, an end plug affixed in the interior of the nose end of the tube, and a replaceable resilient molded plastic ring friction fitted over the nose end of the tube and extending over the portion of the tube exterior proximate the nose end, said ring having an exterior diameter greater than that of the proximate portion of the tube so as to stand proud of the tube, the portion of the ring exterior surface which overlies the nose end being rounded to provide a smooth bearing surface for contact by the filamentary material as it is drawn from the nose end of the pirn, the portion of the ring exterior surface which overlies the exterior surface of the tube being a transition in the form of a gradual conical taper between said rounded surface and said tube exterior, the interior surface of the ring having a substantial area for frictional retention of the ring on the exterior surface of the tube.