US3161100A

US3161100A - Fiber cutting apparatus with opposed guide elements

Info

Publication number: US3161100A
Authority: US
Inventors: Resor John Charles
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1962-09-05
Filing date: 1962-09-05
Publication date: 1964-12-15
Anticipated expiration: 1981-12-15

Description

Dec. 15, 1964 J. c. RESOR 3,161,100

FIBER CUTTING APPARATUS WITH OPPOSED GUIDE ELEMENTS Filed Sept. 5. 1962 3 Sheets-Sheet l INVENTOR JOHN CHARLES RESOR Dec. 15, 1964 c, RESOR 3,161,100

FIBER CUTTING APPARATUS WITH OPPOSED GUIDE ELEMENTS Filed Sept. 5, 1962 3 Sheets-Sheet 2 INVENTOR JOHN CHARLES RESOR ATTORNEY BY ZQzM Dec. 15, 1964 c, RESOR 3,161,100

FIBER CUTTING APPARATUS WITH OFPOSED GUIDE ELEMENTS Filed Sept. 5, 1962 3 Sheets-Sheet 3 FIG.6

N VEN TOR so 1 JOHN CHARLES RESOR ATTORNEY United States Patent 3,161,100 FIBER CUTTING APPARATUS WITH OPPOSED GUIDE ELEMENTS John Charles Resor, Waynesboro, Va., assignor to E. I.

du Pout de Nemours and Company, Wilmington, Del.,

a corporation of Delaware Filed Sept. 5, 1962, Ser. No. 221,477 1 Claim. (Cl. 83-403) This invention concerns an improved apparatus for high speed cutting of tows or ropes of continuous synethic filaments into staple fibers, and more particularly it concerns a modification of a Beria-type cutter apparatus to eliminate long fibers from the cut staple.

In the production of textiles it is highly important in nearly all operations to maintain a high degree of uniformity. Occasional excessively long fibers in staple fibers can cause difficulties in subsequent carding and spinning operations and also result in non-uniformities in finished fabrics. Such non-uniformities in the yarn are usually in the form of cockles or slubs and their presence in a fabric will devalue the fabric.

In the cotton spinning system as well as in the worsted system, the carding and spinning machines are carefully adjusted to suit the particular length of the staple product. In the drafting operation the distance between the back rolls and the front rolls also referred to as the feed rolls and drafting rolls, is usually one-sixteenth inch greater than the length of the staple. When a long fiber goes through these rolls, it will be engaged by the drafting rolls before it is released by the feed rolls, and since the drafting rolls rotate faster than the feed rolls, the filament will be stretched or even broken. This will cause a cockle or slub in the yarn and will often cause a break in the yarn or in the roving. Such breaks decrease the efficiency of spinning. Even if the filament is not broken the stretching beyond its elastic limit will greatly increase its shrinkage and will alter its luster and cause defects in the finished fabrics produced from the yarn. These defects will be accentuated in dyed fabrics.

The conventional Beria cutter, first described in US. Patent No. 1,723,998, is widely used for cutting synthetic filaments, in the form of tow or rope, into staple. This conventional cutter, however, occasionally produces excessively long fibers, usually twice the normal desired length, in the staple products.

A number of attempts have been made in the past to overcome the problem of long fibers in synthetic staple products. Some of these efforts have resulted in patents which may have given some relief, but which have not solved the problem basically. Curtis, US. Patent No. 2,424,555, claims an automatic stop for the cutter and a means for detecting filament ends of excessive length. But the patent does not teach a method for avoiding the production of long fibers.

Thompson, in US. Patent No. 2,232,496 also teaches a method of removing long fibers from out staple at the cutter but does not disclose a method of avoiding the ,production of long fiber.

Peterson, US. Patent No. 2,646,121, attempts to solve the problem by installing a second knife on the Beria cutter with the object of having the second knife cut any filaments missed by the first knife. But since the second knife is placed at a distance of several degrees of are from the first knife, it will have to be placed at a greater radial distance from the rotating disc if it is to cut staple of proper length, and under these conditions, cutting is less efiicient, especially for the tough synthetic fibers with which the present invention is concerned. Furthermore, even with two knives all the filaments were not cut, orcut uniformly, since some of the filaments which missed the ting.

first knife also missed the second knife. The additional cost of installing and maintaining two knives instead of one made this an unduly expensive and impractical means of operation. 7

It has been discovered that the cause of the unduly long filaments in staple products cut on the conventional cutter apparatus was that, as the flaring or spreading rope bundle extended from the rotating nozzle, some of the filaments were positioned laterally beyond the region of contact of the knife and nozzle, and hence were not being cut at each rotation of the nozzle. This area of no contact results from the bevel at the end of the nozzle which projects the continuous rope or tow beyond the surface of the rotating disc to be sheared by the stationary knife. This equipment is shown in the drawings of US. Patent No. 2,631,667, FIGURES 1, 3, and 4 thereof. In FIGURE 3 of that patent it will be seen that the knife edge does not contact the leading edge of the projecting nozzle since the leading edge is beveled. A preferred arrangement and practice of the teaching of US. Patent No. 2,631,667 requires reorientation of the beveled surface, either clockwise or counterclockwise, relative the rotational path of the nozzle. Thus the beveled surface is not directed strictly toward the forward part of the nozzle as shown in FIGURE 4 thereof, but is rotated toward one side. If the beveled surface of the cutter nozzle as shown in FIG- URE 4 thereof is reoriented 30 in a clockwise direction and the projecting nozzle face is considered as the face of a clock with the leading point of the nozzle as 6 oclock, the beveled portion of the nozzle face extends from about 4 oclock to 10 oclock. It was found that most of the uncut filaments were from the side of the nozzle where the bevel extended to about the 10 oclock position. The angle of the knife roughly corresponds to the angle of the beveled portion of the nozzle as shown.

An object of the present invention is to eliminate long fibers from staple of synthetic fibers. A further object is to modify a Beria cutter apparatus in such a way that it will cut fibers of highly uniform length.

These objects are accomplished in the present invention by installing a guide element positioned and arranged in the housing of the Beria cutter and cooperating with the knife and nozzlesso that all of the filaments of the rope will be directed into the effective shearing zone of the cutter.

The details of construction and operation of a preferred embodiment of the present invention, and the accomplishment of the objects, the utility, and the advantages thereof will be made more clearly apparent by reference to the following detailed description when taken in conjunction with the accompanying drawings in which like elements in the various views are referred to by like characters of reference.

FIGURE 1 is a cross-sectional view in elevation of an apparatus constructed in accordance with the present invention.

FIGURE 2 is a partial view in cross-section taken along section line 22 of FIGURE 1 showing the construction and arrangement of a guide element and associated parts.

FIGURE 3 is a view in partial cross-section taken along section line 3-3 of FIGURE 2 showing a guide element within the housing and a rotatable disc member with a single projecting nozzle, the nozzle being shown in three different positions advancing toward a cutting member.

FIGURE 4 is a partial head-on view of a nozzle face engaging a knife edge in the absence of a guiding element, showing the manner in which some filaments fiare out so as to miss the effective shearing zone.

FIGURE 5 is a top View of the FIGURE 4 structure showing discharging filaments being guided into the effective shearing zone just prior, .in point of time, to cut- FIGURE 6 is a showing similar to FIGURE wherein the discharging filaments have been guided into the eifective shearing zone at the time of actual cutting.

FIGURE 7 is a representation of an alternate embodiment, showing a pair of guide elements, similar to the showing of FIGURE 3.

Referring now to FIGURES 1, 2, and 3, the embodiment of the apparatus selected for illustrating one preferred embodiment generally comprises a rotatable disc member 1 having a passageway 2 therein for receiving a tow 3 of continuous filaments fed by suitable means into a funnel portion 5 of the passageway 2 while the disc member 1 is rotating. The discharge portion of the passageway 2 extends substantially radially of the disc members 1 rotational axis through a hollow shear member 6 or cutter nozzle adjustably mounted in a block 7, the shear member 6 having a face 8 projecting from the periphery 9 of the disc member 1. The apparatus further comprises stationary housing means, means for rotating the disc member, cutting means, filament guiding means, and a trough It) for carrying away the discontinuous lengths of cut filaments. The disc member 1 is substantially enclosed by upper and lower shroud members 11 and 12 and may be driven by any suitable rotary drive means such as a belt in driving engagement with a pulley 13 mounted on a shaft 14 journaled in bearings 15 and 16.

The disc members 1 passageway 2 may be provided with a replaceable throat member 17 suitably mounted at the discs 1 axis of rotation and a channel liner 18 suitably mounted in the radially extending portion of the passageway 2. The periphery 9 of the disc 1 is cut out to receive the block 7 which is secured in the disc 1 by means of set screws or the like for easy removal from the apparatus. The hollow shear member 6 is adjustably mounted in the block 7 by suitable means.

The projecting face 9 of the shear member 6 preferably comprises a first surface 20 beveled toward the periphery 9 of the disc member 1 and out of contact with the cutting edge 23 of the cutting member or knife 22. And, a second surface 21 curved concentrically with the periphery of the disc 1. As may be seen in FIGURES 5 and 6, the shear member 6 has a substantially round crosssection, and the passageway extends through the first and second surfaces, 20 and 21, of the projecting face 8. Thus a shearing edge 24 having a leading portion 25 and a trailing portion 26 is established in the second surface 21 of the shear member 6. The intersection of the passageway with the projecting face forms the discharge orifice 27 for the continuous filaments.

The inner walls of the shear member 6 are preferably tapered in a conventional manner. The discharge orifice 27 is eccentrically positioned relative the outer walls of the shear member 6. Substantially increased shearing or cutting efficiency is accomplished by orienting the shearing edge 24 by angularly positioning the shear member 6 about its axis a given amount, relative the direction of rotational movement (shown by arrows in the drawing views), so that one portion 25 of the edge 24 is continually in advance of the other portion 26. Either of the portions, 25 and 26, may be oriented to the advanced position.

The cutting member or knife 22 is conventionally mounted in a rigid manner, not shown, when the apparatus is operative. Also, close horizontal and vertical prepositioning of the knife 22 relative to the hollow shear members 6 face 8 is conventionally accomplished. The cutting edge 23 of the knife 22 is preferably positioned substantially parallel to the intermittent intersecting edge formed between the shear members 6 first and second surfaces, 20 and 21, as may be seen in FIGURES 3 and 6. An effective filament shearing zone, designated in the drawings by the alphabetical letter Z, is periodically established between the moving shearing edge 24 and the stationary cutting means.

The filament guiding means or guiding device comprises at least one guide element 28 having an arcuate shape of relatively thin cross-section. As shown in FIG-

URES

2 and 3, the guide element 28 is secured to the shroud member 12 of the housing near a first end portion 29 of the element 28. This is accomplished by means of a countersunk pad 31 welded to the guide element 28 and the combination being anchored to the shroud 12 by a flat-head machine screw 32 and nut 33, or other suitable fasteners. The guide element 28, preferably made of a corrosion resistant stainless steel material, has a second end portion 30 secured to shroud 12 by means of a mounting plate 34 anchored to the shroud 12 with a socket head machine screw 35 and nut 36. The element 28 is fixed to the mounting plate 34, with one or more spacers 37 therebetween, by fiat-head machine screws 38 locked in the guide element 28 so as to rigidly fix the mounting plate 34, the spacers 37, and the guide element 28 to the shroud member 12.

In the preferred embodiment, the guide element 28 has a slight double bend, at 39 and 40, so that the angle of the guide element 28 relative the lower shroud member 12 (or relative the radial plane of the disc member 1) is approximately 9 to 10; however, this degree of angle is not necessarily critical. Sufiicient spacers 37 are provided near the guide elements 28 second end portion 30 so that the end portion 30 overlaps the side of the discharge orifice 27 of the shear member 6 nearest the shearing edges 24 trailing end. The selectively adjustable amount of over-lapping should be sumcient to preclude discharging filaments from fiaring beyond the effective shearing zone Z periodically established between the shearing edge 24 and the cutting edge 23. The guide elements 28 inner face 42 facing the disc members 1 periphery 9 is substantially uniformly spaced slightly outside of the rotational path of the shear members 6 maximum outwardly extending second surface 21.

In operation, a tow 3 or rope of continuous filaments is fed by suitable feeding means into the funnel portion 5 of the passageway 2 in the disc member 1 while the disc 1 is being rotated at a uniform speed in one direction. The rate of feed of the tow 3 to the disc 1 and the rotative speed of the disc 1 are so adjusted that the tow 3 advances an amount equal to the desired length of staple to be cut per revolution of the rotatable disc member 1. The passageway 2 in the vicinity of the funnel portion 5 extends substantially in the direction of the rotational axis of the disc 1, and then extends radially of the discs axis so that the tow 3 will be advanced through the passageway 2 primarily by centrifugal force due to the rapid rotation of the disc 1. Some process fluids may also be utilized to assist this advancing action. The tow 3 then passes, with considerable velocity, out through the shear member 6 which is rotating with the disc member 1.

In each revolution of the disc member 1, a predetermined length of the tow 3 or rope issues from the shear member 6 as seen in phantom in FIGURES 2 and 3. Individual filaments of the tow 3 (such as the lower filaments shown in FIGURE 4) that may be tending to flare laterally outside of the effective shearing zone Z which is about, in point of time, to be formed between the shear members 6 shearing edge 24 and the cutting members 22 cutting edge 23 are positively engaged and positioned on the filament engaging surface 41 of guiding element 28. Any flaring filaments slide relative to this surface 41 and are moved laterally back toward the center of the tow 3 and into the effective shearing zone Z. The tow 3 is periodically sheared or sliced into uniform staple lengths by engagement between the moving shearing edge 24 and the stationary cutting edge 23. The uniform cut lengths of staple fibers then drop, or are assisted, into a trough 10 from where they are conveyed to the next process operation.

In the described embodiment, the rotatable disc mem ber 6 should be of sufiicient diameter that its peripheral velocity will be great enough to force the rope 3 through the radial channel portion of the passageway 2 to assist in the effective cutting of the filaments at a practical rotational speed. For a single knife 22 a relatively small diameter disc 1 can be used, but where several knives 22 are used around the periphery 9, a larger diameter would be desirable. One embodiment of the improved cutter has the following dimensions:

(a) The radius of the rotatable disc member 1 is 9.75 inches,

(b) The projection of the shear member 6 beyond the periphery 9 of the disc 1 is 0.5 inch for a new shear member 6 and about 0.25 inch for a used shear member 6 which has been eroded away by the knife 22,

(c) The radius of the inner face 42 of the guide element 28 is 10.5 inches,

(d) The radius of the outside face of the guide element 28 is 13.5 inches,

(e) The arcuate length of the guide element 28 (exclusive of a one inch tip) is 13.7 inches,

(f) The angle subtended by the latter are is 75, and

(g) The angle of the guide 28 with the shrouds, 11 and 12 (or with the radial plane of the disc 1) is 9 to These individual dimensions are characteristic of one embodiment of the invention which is operable. Slight variations in the length of the guide element 28, the width of the element 28, or the angle the element 28 makes with the shroud member 12 will not significantly modify the general operation of the apparatus.

If a pair of converging guide plates are used in the practice of this invention, as shown in FIGURE 7, the angle at which the guide elements 28 approach each other (twice the angle each element 28 makes with its respective mounting shroud element or with the radial plane of the disc 1) is preferably about 18 to about 20. This gentle slope will gradually move the laterally flared filaments from both sides toward the center of the tow 3 without the exertion of undue force on individual filaments.

The use of this improved apparatus substantially eliminates the contamination of staple with over-length fibers and results in production of higher quality fabrics. Also, most existing art cutters of this general type may be readily modified to incorporate the advantages of the arrangement of this invention.

In accordance with the patent laws, a preferred embodiment of this invention has been disclosed in detail. Numerous changes and modifications within the spirit of the invention will occur to those skilled in the art and all such are considered to fall within the scope of the following claim wherein:

I claim:

An improved apparatus for cutting continuous filaments into uniform lengths comprising, in combination, a stationary housing means, a rotatable disc member mounted in said housing means for unidirectional rotation about an axis, means for feeding continuous filaments into said rotatable disc member, means for rotating said disc member about said axis, a shear member having a face projecting from the periphery of the disc member, said face comprising a first surface beveled toward said periphery and a second surface curved concentrically with said disc periphery, a passageway within the disc member for movement therethrough of said incoming continuous filaments, said passageway extending substantially radially of said axis through the shear members first and second surfaces to form a discharge orifice in said projecting face for the continuous filaments, the shear members shearing edge being the portion of said orifice established 6 in said second surface, a cutting means arranged at a fixed position in the path of said discharging filaments for cooperating engagement with said shearing edge to periodically engage and cut said discharging filaments into predetermined uniform lengths, and filament guiding means mounted in said housing means substantially ahead of and extending into the zone of effective engagement between the cutting means and the shearing edge, said positioned substantially parallel to an intermittent intersecting edge formed between said shear members first and second surfaces; said passageway being circular in crosssection at said passageways intersection with said projecting face of the shear member; and said filament guiding means comprises a guiding member, said member having an inner surface spaced closely adjacent said disc members periphery slightly outside of the rotational path of the shear members second surface, said device further arranged to converge from a region of one outer face of said disc member inwardly toward said effective shearing zone in a manner such that said device overlaps a side of said discharge orifice near said shearing edges trailing portion, said guiding member comprising at least one guide portion having an arcuate shape of relatively thin cross-section, said guide portion having a filamentengaging face gradually inclined from a first position upstream of said cutting means spaced laterally from the path of the shear member face to a second position in said overlapping relation to the path of shear member face, said filament-engaging face being further constructed and arranged for smoothly slidably engaging the discharging filaments fiaring laterally from said orifice in the direction of said portion and sequentially positioning the flaring filaments into a compact bundle for movement through the effective shearing zone, said guide member being provided with means for relatively adjusting the extent of said overlapping relation so as to maintain effective cutting of all said discharging filaments by the engagement of the cutting members cutting edge and the shear members shearing edge, and said guiding means further comprising a second guide member opposed to said first member, each member having a corresponding arcuate shape of relatively thin cross-section and each being arranged to converge toward the other as they approach said effective shearing zone. in the direction of disc member movement so that they overlap two opposing sides of said discharge orifice and positively maintain the discharging filaments in the efiective shearing zone by physical engagement with both sides of a group of fila ments discharging from said orifice.

References Cited in the file of this patent UNITED STATES'PATENTS 2,232,496 Thompson Feb. 18, 1941 2,323,644 Castellan July 6, 1943 2,631,667 Schmitz Mar. 17, 1953 2,646,121 Peterson July 21, 1953