US2306377A - Method for preparing worsted yarns - Google Patents

Description

Dec. 29, 1942. w. F. BIRD ETAL 2,306,377

METHOD FOR PREPARING WORSTED YARNS Filed March 8, 1941 IF'ICZM.

INVENTORS wHrrwom-H F. BIRD mzsoemcamcomuzu.

' WILLIS B. o qs eeo BY ATr RNEY Patented Dec. 29, 1942 UNITED STATES PATENT OFFICE METHOD FOR PREPARING WORSTED YARNS Whitworth F. Bird, Wallingford, Pa., and Frederick A. Cornell and Willis B. Goodspeed, Bristol, R. L, assignors to Collins & Aikman Corporation, Philadelphia, Pa., a corporation of Delaware Application March 8, 1941, Serial No. 382,316

8 Claims. (Cl. 57-156) This invention relates to the spinning of worsted yarns or yarns of the worsted type by a high draft system, comprising either one or two essential stages, depending on the type of stock bethe interfacial friction of the fibers be such that there is no relative motion between fibers which are not engaged by the forward nip of the single or last draft stage. We have discovered that when these conditions are present, as will be more fully explained hereinafter, the permissible draft in the last or single stage may be as high as dethat when the fibers emerge from the front roll ers of the draft stage they will all be formed into twisted stock at the twist point near the nip which is created by a twisting or spinning device conveniently positioned forwardly of and below the forward rolls. When these conditions are met the draft may be a great deal higher than the length in inches of the bulk of the longest fibers or of the longest fibers of the worsted.

stock.

The present invention is of great importance to the worsted and allied industries in that it permits the elimination of many steps common sired, single stage drafts of fifty and upward being entirely feasible.

According to a preferred embodiment ofthese improvements, a substantially uniform. strand of worsted yarn forming stock is twisted. This strand may be prepared specially for the operations which are to follow or maybe a result of a normal prior twisting operation. The twisted strand is then mounted behind feed rolls and fed forwardly. The feed rolls may constitute the back rolls for the first drawing operation. From the feed rolls the stock passes over a set of driven carrier rolls which support the stock and rotate as the stock advances into a forward pair of drawing rolls each of which is covered with a traveling endless apron or belt. The draft induced by this operation is sufiicient to remove the twist from the strand as it passes the nip point of the belt. The stock is thus controlled by the twist until engaged by the nip, after which the endless aprons act as a conveyor and control medium for the wholly untwisted stock as it approaches the forward set of drawing rolls.

Worsted yarns consist of wool fibers of nonuniform length and which are relatively parallel. The worsted stock fibers are non-uniform in length. These fibers may be processed alone or with other fibers such as mohair or staple synthetic fibers of like lengths to form worsted typeyarns, as is well understood.

According to this invention, worsted fibers or fibers of the worsted type are fed to or positioned within a draft stage without twist, excessive condensation or thickness, the width being such to the conventional worsted systems such as the Bradford system, and may be performed on relatively simple mechanism. The concept is characterized by its departure from the concept of condensation of the fibers being drawn, hereto fore believed necessary in both the cotton and so-called high draft and worsted processes.

Cotton fibers, which are relatively short and substantially uniform in length, are normally twisted together in thelast stage. In the case of worsted drawing as in multi-stage drafting, it has been suggested tocondense the-stock between the stages with the result that the stock in the final stage is so thick that individual positive fiber control is impossible and the amount of draft is restricted. A draft of 10 is consideredvery high in a single stage and fiber breakage, slubs and twitty yarn is very likely to result even at this draft. It has heretofore been considered a rule in conventional Worsted drafting that the drafts be low, i. e., of the order of 6 or 7, and. that a sliver must never be drafted twice in the same direction. According to these im provements, the draft may be made in a single stage and may be as high as desired.

An object of this invention is to provide a high draft apparatus and method of spinning fibers of non-uniform length.

Another object is to provide a. high draft apparatus for yarns of the worsted type.

Another object is to provide a two stage high draft apparatus for yarns of the Worsted type in which any desired draft may be accomplished.

Another object is to provide a draft stage unit in which the fibers are positioned in a relatively thin fiat band which is controlled by vertical top and bottom pressure only as the band approaches a twisting device.

Another object is to limit .the width of the fiat band as it emerges from the single or last draft.

Another object is to provide a system of worsted spinning having a stage wherein there is no relative movement of fibers within the stage except between those actually engaged by the formanifest from a consideration of the following description, claims and drawing, in which:

Figure I is a diagrammatic assembly in side elevation showing the arrangement of a preferred embodiment of the invention.

Figure IIis a vdetail view showing the front draft rollers and the thin band of fibers emerging therefrom being twisted.

Figure III ,is a detail view similar to Figure 11. showing a band of fibers in which each fiber engages both rollers.

Figure IV is a modification of the belt assembly.

Referring to Figure I, a frame ID has an inclined support II for pins l2, over which the worsted stock supply bobbins l3 carrying twisted stock I are positioned. The amount of twist may vary within reasonable limits, but should be sufiiciently high to effect some control of the stock in the first stage and sufiiciently low so that all or substantially all of the twist is removed by the first drafting operation.

A forked guide i5 guide the twisted stock I 4 from the supply bobbins l3 through positively driven pressure rollers I6, I1 and I8, mounted on a pair of brackets such as l9. These pressure rollers will cause the twisted stock to lie side by side to form a band of twisted stock. The rollers l1 and i8 constitute feed rollers and are the back rollers of the first draftstage.

Brackets 29 support positively driven carrier rollers 2|, 2 2 and 23, over which removable rollers 24, 25 and 26 rest. The rollers 24, 25 and 26 are not positively driven and merely rest on the worsted stock. As the stock advances it enters between the endless belts 21 and 28 which pass about the rollers 29 and 38 respectively to form a nip to complete the first draft stage. The ratch of this stage will depend on the length according to accepted worsted drawing and will be slightly longer than the length of the bulk of the longest fibers. fibers is 8 inches, for example, the ratch may be 9 inches.

The belts 21 and 28 function first as a nip and then as a conveyor, for the worsted stock M, which is without twist between the belts and in the form of a fiat thin band. The roller 38 is positively driven, whereas the roller 29 may rest in slotted bracket 3|. Bracket 32 is movable along bracket 3| and supports belt guide rollers 33 and 34. The bracket 3| is also adjustably mounted on the frame "I and the rollers 29 and 38 may be weighted to effect desired control. The belt 28 should provide a firm surface for controlling the fibers and, of course, additional support may be provided along its length if desired.

,;-The control is regulated so that the weight of the upper rollers 29 and 33 and belt 21 retains the thin band of untwisted fibers against any movement due to the interfacial friction of the If the bulk of the longest final spinning frame.

fibers, and only those fibers are drafted which have passed under the nip of the forward roller 35 and idle roller 36 which rests in slotted bracket 31. The exact permissible thickness of the band between the belts will depend on the size and nature of the stock being worked, and it width will be such as. can be converged to the twist point 38 forwardly of the forward rollers 35 and 36 ,of the second stage. As before stated, there must be no excessive compression offibers prior to leaving the belt 21-28. The wild fibers at the extreme edges of the band on leaving the belt may, however, be lightly pressed toward the body of the band to insure that all are within the twist range.

As the stock leaves the rollers 35 and 36 it converges to a twist point 38 created by a twisting device generally depicted as' 39. A pigtail guide 48 may be mounted on the frame it) between the front rollers and the twisting unit.

they maybe about and independently driven by separate rollers and/or the upper belt may be entirely removed.

The invention may be used prior to present day equipment to produce rovings for the final spinning frame, or may itself constitute the In the first case, a typical run to produce a roving for the final spinning frame is as follows:

Three strands of stock, the bulk of the longest fibers of which is approximately 8 inches in length and each weighing 166 drams per 40 yards, are fed to the squeeze rolls I6, I! and I8. The stock carries a twist of .24 turn per'inch. The stock is approximately .375 inch in diameter and will be positioned side by side by the squeeze rolls. A draftof 5 in the first stage will provide completely untwisted stock in the form of a thin fiat band within the second stage. The band is approximately 1% inches wide between the belts and as it emerges from the rollers 35 and 36 it converges to the twist point 38. A draft of 28 in the second stage will result in a two stage draft of and a roving weighing 5 drams per '40 yards. Like rovings may be made from 3 ends of 300 drams, .5 inch wide, of twisted worsted stock having .18 turn per inch. In this case the draft may be 5 and 36 respectively in the first and second stages. Two ends of 500 drams worsted stock having .10 turn per inch will require drafts of 5 and 40 to produce a similar roving. The unit of weight in each case is in per 40 yards, as will be understood.

As hereinbefore stated, the draft may be considerably higher but, of course, sufiicient fibers must be within the untwisted band width to converge and form a twisted strand without excessive breakage. To insure this condition, the stock may be run through two similar machines, the first producing worsted forming twisted stock having, for example, .88 turn per inch and weighing 35 drams per 40 yards. Each strand is approximately inch wide. By introducing 2 of these twisted strands and providing successive drafts of 5 and 21 a final yarn weighing .65 dram per 40 yards may be formed. The strand as it leaves the front rollers will be approximately A inch wide and may be twisted as desired, for example to 13.7 turns per inch.

, verged to the twist point after leaving the front rollers in untwisted condition. It will be seen that there is no excessive condensation of the fibers and that they will move with the belt until actually engaged by the forward nip.

' Figure III illustrates all the fibers being in contact with the rollers with just sufficient stock to converge without excessive breakage. The critical point will, of course, be'determined by the nature of stock being worked.

Figure IV, illustrates a modification of the belt assembly in which only one belt which does not form the nip is used. In this modification, brackets 42, 43 and 44 are mounted on the frame Ill. The rollers 45 and 46 constitute the back rollers of the forwardgdraft stageand conveyor belt" passes around driven rollers 48 and 49. The rollers 45, 48 and 49 are driven so that the belt 41 acts as a conveyor for the untwisted stock. The surface speed of the belt is substantially the same as the surface speed of the nip forming rollers. Rollers 50' and 5| rest on the stock and may be weighted if desired. As in Figure I,

the distance between the belt and forward rolls is very short, i. e., about one inch, or even less. In general, this distance should be as short as possible to effect positive control of all of the fibers.

The illustration used for the production of final yarns recites successive drafts of 5 and 21 /2, drafts of approximately in the second stage being convenient and very workable for worsted stock according to the invention.

The several illustrations contained herein are not intended to constitute definite limits, and desiring to be restricted only by the scope of the attached claims of the invention, we claim:

1. In a process of making worsted type yarn from fibers of non-uniform length, the steps of feeding a plurality of twisted strands of stock into a draft stage so that the strands nter the drafting area relatively close to one another, correlating the draft stage to the twist in the strands of stock so as to remove all of the twist from the stock, advancing the untwisted stock into a second draft stage, providing a top and bottom retaining drag on all of the untwisted fibers of the second draft stage, said retaining drag being such as to allow a longitudinal movement of the fibers without breakage but preventing any substantial relative fiber movement due to the interfacial friction of the fibers, positively drawing off the untwisted fibers progressively, and then twisting the drawn off fibers together.

2. In a'process of making worsted type yarns from fibers of non-uniform length, the steps of feeding a plurality of twisted strands of stock into as to allow a longitudinal movement of the fibers without breakage but preventing any substantial relative fiber movement due to the interfac'ial vfriction of the fibers, positively drawing off the untwisted fibers progressively, and then twisting the drawn off fibers together.

3. In a process of making worsted type yarns from fibers of non-uniform length, the steps of feeding a plurality of twisted strands of stock into a draft stage so that the strands enter the drafting area relatively close to one another, correlating the draft of the draft stage to the twist in the strands of stock so as to remove all of the twist from the stock, advancing the untwisted 2 stock into a second draft stage, providing a top and bottom retaining drag on all of the untwisted fibers of the second draft stage, said retaining drag being such as to allow a longitudinal movement of the fibers without breakage but preventme any substantial relative fiber movement due to th interfacial friction of the fibers, positively drawing of! the untwisted fibers progressively at approximately twenty times the rate of feed into the second draft stage, and then twisting the drawn ofl fibers together.

4. In a final or intermediate process of making worsted type yarns'from'fibers of non-uniform length without folding or other substantial centralizing of the fibers, the steps of feeding a plurality of twisted strands into a draft stage so that the strands enter the drafting area relatively close to one another, correlating the draft of the draft stage to the twist in the strands of stock so as to remove all of the twist from the strands, advancing th untwisted stock into another draft stage in the form of a single relatively-wide band of fibers, providing a top and bottom pressure retaming-drag on the untwisted fibers which make up the strand in the second stage, positively drawing of! the untwisted fibers substantially progressively, and then twisting the relatively wide band a draft stage so that the strands enter the draft-' a ond draft stage, said retaining drag being such worsted type yarns from fibers of non-uniform length without folding or other substantial centralizing of the fibers, the steps of feeding a plurality of twisted strands into a draft stage so that the strands enter the drafting area substantially side by side, correlating the draft of the draft stage to the twist in the strands of stock so as to remove all of the twist from the strands, advancing the stock over a relatively wide area into another draft stage, providing a top and bottom pressure retaining drag on the untwisted fibers in the second draft stage, positively drawing off the untwisted fibers substantially progressively, and then twisting the drawn off fibers of the relatively wide area together.

6. In a final or intermediate process of making worsted type yarns from fibers of non-uniform length without folding or other substantial centralizing, the steps of feeding a plurality of twisted strands into a draft stage so that the strands enter the draftingarea relatively close to one another, correlating the draft of the draft stage to the twist in the strands of stock so as to remove all of the twist in the stock, advancing the untwisted. stock into a second draft stage, providing a top and bottom pressure retaining drag on all of the untwisted fibers of the second draft stage, said retaining drag beingsuch as to allow a longitudinal movement of the fibers without breakage by preventing any substantial relative fiber movement due to the interfacial friction of the fibers, positively drawing off the untwisted flbers progressively, and then twisting the drawn off fibers together. v

7. In a final or intermediate process of making worsted type yarns from fibers of non-uniform length without folding or other substantial centralizing, the steps of feeding a plurality of twisted strands into a draft stage so that the strands enter the drafting area relatively close to one another, correlating the draft of the draft stage to the twist in the strands of stock so as to remove all of the twist in the stock, advancing the untwisted stock into a second draft stage in the form of a single band of fibers, providing a top worsted type yarns from fibers of non-uniform length without folding or other substantial centralizing, the steps of feeding a plurality of twisted strands into a draft stage so that the strands enter the drafting area relatively close to one another, correlating the draft of the draft stagetothetwistinthestrandsofstocksoasto remove all of the twist in the stock, advancing the untwisted stock into a second draft stage, providing stop and bottom pressure retaining drag on all of the untwisted fibers of the second draft stage, said retaining'drag being such as to allow a longitudinal movement of the fibers without breakage but preventing any substantial relative fiber movement due to the interfacial friction of the fibers, positively drawing 0! the untwisted fibers progressively at approximately twenty times the rate of feed into the draft stage, and then twisting the-drawn 0E fibers together.

WHITWORTH 1". BIRD. FREDERICK A.CORNELL.

WILLIS B. GOODSPEED. v

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