US3302839A

US3302839A - Tow-diverting chute for depositing running tow on a conveyor belt

Info

Publication number: US3302839A
Application number: US442590A
Authority: US
Inventors: Spruill William Hampton
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1965-03-25
Filing date: 1965-03-25
Publication date: 1967-02-07
Anticipated expiration: 1984-02-07
Also published as: DE1939424U

Description

Feb. 7, 1% w. H. SPRUILL 3,392,839

TOW-DIVERTING CHUTE FOR DEPOSITING RUNNING TOW ON A CONVEYOR BELT Filed March 25, 1.965

INVENTOR WILLIAM HAMPTON SPRUILL ATTORNEY United States Patent 3,302,839 TOW-DIVERTING CHUTE FOR DEPOSITWG RUNNiNG TOW ON A (IQNVEYUR BELT William Hampton Spruill, Kinston, N.C., assignor to E. I.

du Pont de Nemours and Company, Wilmington, Dek,

a corporation of Delaware Filed Mar. 25, 1965, Ser. No. 442,590 3 Claims. (Cl. 226-196) This invention relates to tow delivery apparatus for depositing on a surface in a sinuous pattern a running length of yarn or tow composed of a plurality of filaments. It is more particularly concerned with a tow-diverting chute for use in such apparatus to deliver running lengths of tow at high speeds to tow-receiving means, which may be a conveyor belt or shipping containers used for forming large packages of tow from which tow lengths are readily removed.

In the handling of yarns or tows on the run, difficulty is usually encountered in static generation, filament or yarn breakage, wrap formation, tension variation, snagging, and the like. When a large number of yarn ends are being run simultaneously, these difliculties are especially serious and must be avoided. Many devices and apparatus have been described to overcome or avoid specific problems occurring, particularly in the processing of a tow composed of a large number of filaments, which deal with a driving device for the tow or for controlling the laydown pattern of the tow on a conveyor in order to facilitate drying of the tow. All of these devices have successfully overcome the problems for which they were intended but they have been of little assistance in overcoming the prob lems of snagging of a few of the filaments of the tow bundle in the laydown chute. It is especially important to overcome this problem in delivery mechanisms used for high strength synthetic fibers, Where a few filaments snagged in the chute will support a heavy tow. When snagging occurs, subsequently delivered tow will bunch and plug the chute or accumulate until there is sufficient tow weight to break or pull the snagged filaments free, causing erratic delivery and poor quality. High-speed operation multiplies this difiiculty because such interruptions will form quickly and grow to serious proportions before an operator can shut down the equipment.

An object of this invention is to provide an apparatus for diverting a traveling tow to a position at which the tow is to be laid down .on a conveyor for additional processing steps such as washing or drying. Another object is the provision of an apparatus for the snag-free, consolidated discharge of a tow into a sinuous pattern .on a conveyor belt or into a package. Other objects will appear hereinafter.

In the drawing, which illustrates an embodiment of the invention,

FIGURE 1 is an isometric projection of the chute, and

FIGURE 2 is a schematic view of apparatus utilizing the chute of FIGURE 1.

Referring to FIGURE 1, the chute 1 is formed of wire cloth, preferably 8 x 8 mesh (3.15 x 3.15 mesh per centimeter), of 0.033-inch diameter (0.838 mm.) stainless steel wire supported by a frame 2 which is suitably attached to the edge of the wire cloth by polished joints of brazing, welding or the like. The frame 2 includes at least an upper yoke 3 and a lower yoke 4, which are attached to a rod 5 and brace 6. Stub shafts 7 are attached to the upper yoke 3 to provide a pivotal means of support in bearings. The chute is smoothly curved through an arc of about 60 and tapers from the top to the bottom of the chute to divert and consolidate the tow to be deposited.

FIGURE 2 shows the above chute positioned in a tow delivery apparatus of a type which is conventional in other respects. As illustrated, the tow descends approximately 3,302,339 Patented Feb. 7, 1967 vertically into the entrance of the pivotally-mounted c'hute 1 of wire cloth. The tow is consolidated by the converging wire cloth walls of the chute, diverted to a near horizontal direction by the curvature of the chute, and discharged from the mouth of the chute onto a moving conveyor belt or into a suitable container. Oscillation of the chute about the pivotal support by conventional means causes the tow to be laid down on the conveyor belt in a sinuous pattern which is dependent on the frequency and amplitude of oscillation of the chute.

The chute is useful for directing the path of a moving tow bundle of synthetic filaments which have been crimped or of filaments which are uncrirnped. The chute of this invention is particularly useful in apparatus for handling a wet tow of uncrirnped filaments. In such apparatus, smooth-surfaced sheet metal funnels or chutes have been found to produce considerable surface friction between the moving tow bundle and the surface of the chute. Particularly, in handling tow which carries a sticky or gummy finish, friction .on this smooth surface is sufficient to snag, separate, and break individual filaments. Many attempts to reduce the surface frictional characteristics of the chute have proven to be unsatisfactory. These attempts have included antifrictional coatings on the surface of the chute, such as coatings of silicones or fluorocarbon polymers, or by the use of matte finishes or other roughened surfaces to reduce the total area of contact between the sheet and the filamentary tow surface. It was indeed surprising, therefore, to discover that the simple use of wire cloth as the surface of the chute was sufficient to reduce the frictional drag of the chute on the tow surface to the point that snagging was eliminated. In addition, the use of wire cloth provides for the separation of excessive amounts of finishes carried on the tow bundle. This may possibly explain why the use of wire cloth chutes so successfully eliminate the snagging conditions, whereas attempts to use matte finish surfaces to reduce frictional characteristics were unsuccessful.

In general configuration, the chute of this invention is similar to chutes of the prior art. Bends and joints should be made as smooth as possible, and the welded joints of the wire to the frame must be ground and polished. The size and shape of the chute depends upon the size and composition of the tow. As an example, in handling a heavy denier tow of about 600,000 denier, a satisfactory chute is tapered from about 9 inches (24 cm.) in width at the top to about 4 inches (10 cm.) in width at its mouth. This chute is positioned approximately 15 from the vertical at its entrance and so as to discharge at an angle of approximately 15 from the horizontal. The curvature of the chute may be a continuous curve approaching that of a section of a catenary or may consist of a straight section which proceeds smoothly into a circular arc of a circle of about 18 inches radius. The chute may be formed of any suitable metallic stiff wire cloth, although an 8 X 8 mesh (3.15 x 3.15 mesh per cm.) stainless steel wire cloth having wires of 0.033 inch (0.838 mm.) in diameter has been found to be particularly suitable. Other materials suitable for use in constructing the chute include expanded metal sheeting or perforated metal sheeting which have well-rounded edges. The over-all length of the chute is preferably about 37 inches (94 cm.), but any length between 30 and 40 inches and cm.) is generally satisfactory.

The chute of this invention operates satisfactorily in handling yarn traveling at high speeds such as 1,200 yards per minute (1100 meters per minute) and above, although it is also quite useful at the low speeds from 100 to 400 yards per minute (.91 to 360 meters per minute) which are often used. The upper limit on operating speed depends in part on the yarn finish and the presence or absence of crimp in the tow bundle. Thus sticky or gummy 3 finish requires a lower maximum operating speed than does uncrimped or low crimp tow. The chute may be used for low denier yarns, for example, 680 denier yarns or smaller. It has particular utility in the high speed packaging or delivery of heavy denier tow such as 600,000 denier and above.

The improved apparatus of this invention is useful in handling running yarn ends or tows of any material, synthetic or natural. 'It is particularly useful in staple production.

It will be apparent that many widely different embodiments of this invention may be made without departing from the spirit and scope thereof, and therefore it is not intended to be limited except as indicated in the appended claims.

I claim:

1. In a tow delivery apparatus for depositing a running length of tow on a conveyor belt in a sinuous pattern, the improvement of a wire cloth tow-diverting chute for delivering the tow to said conveyor belt without snagging, the wire cloth surface of the chute being smoothly curved to divert the running length of tow through an arc of about 60, tapered from about 9 inches in Width at the top to about 4 inches in width at the mouth to consolidate the tow between converging wire cloth walls as the tow passes References Cited by the Examiner UNITED STATES PATENTS 2,363,219 11/ 1944- Adamson 1932 2,523,558 9/1950 Cavalier l932 X 2,722,729 11/ 1955 Wilhelm 2821 2,922,196 l/l960 Kunz et 211.

References Cited by the Applicant UNITED STATES PATENTS 2,468,843 5/ 1949 Nash.

2,598,000 5/1952 Knopp et al. 2,878,547 3/ 1959 McMaster et al. 3 ,104,790 9/1963 De Haven.

M. HENSON WOOD, JR., Primary Examiner.

J. N. ERLICH, Assistant Examiner.

Claims

1. IN A TOW DELIVERY APPARATUS FOR DEPOSITING A RUNNING LENGTH OF TOW ON A CONVEYOR BELT IN A SINUOUS PATTERN, THE IMPROVEMENT OF A WIRE CLOTH TOW-DIVERTING CHUTE FOR DELIVERING THE TOW TO SAID CONVEYOR BELT WITHOUT SNAGGING, THE WIRE CLOTH SURFACE OF THE CHUTE BEING SMOOTHLY CURVED TO DIVERT THE RUNNING LENGTH OF TOW THROUGH AN ARC OF ABOUT 60*, TAPERED FROM ABOUT 9 INCHES IN WIDTH AT THE TOP TO ABOUT 4 INCHES IN WIDTH AT THE MOUTH TO CONSOLIDATE THE TOW BETWEEN CONVERGING WIRE CLOTH WALLS AS THE TOW PASSES THROUGH THE CHUTE, AND OF AN OVER-ALL LENGTH BETWEEN 30 AND 40 INCHES.