US3889899A - Incrementally-tapered bobbins - Google Patents

Abstract

A textile yarn support, such as a hollow impregnated-paper tubular bobbin having a slight overall taper inwardly from bottom to tip, has a ''''stepped'''' external configuration brought about by progressive small reductions in external diameter, by the same amount, of successive adjoining shortlength sections thereof, all of such sections having substantially the same uniform taper, and the relatively abrupt changes from maximum diameter of one section to minimum diameter of the next adjoining section being of less annular width than the diameter of yarn intended to be wound upon the bobbin, thereby promoting uniform and controlled high-speed winding and unwinding of yarn and facilitating clean stripping of waste.

Description

United States Patent 1 Adams et al.

[ 1 INC REMENTALLY-TAPERED BOBBINS FOREIGN PATENTS OR APPLICATIONS 9/1953 United Kingdom 242/118.3

1 June 17, 1975 716,036 9/1954 United Kingdom 242/118.3

Primary Examiner-George F. Mautz Attorney, Agent, or Firm-James E. Mrose 57 ABSTRACT A textile yarn support, such as a hollow impregnatedpaper tubular bobbin having a slight overall taper inwardly from bottom to tip, has a stepped" external configuration brought about by progressive small reductions in external diameter, by the same amount, of successive adjoining shortlength sections thereof, all of such sections having substantially the same uniform taper, and the relatively abrupt changes from maximum diameter of one section to minimum diameter of the next adjoining section being of less annular width than the diameter of yarn intended to be wound upon the bobbin, thereby promoting uniform and controlled high-speed winding and unwinding of yarn and facilitating clean stripping of waste.

1 Claim, 3 Drawing Figures 1 INCREMENTALLY-TAPERED BOBBINS BACKGROUND OF THE INVENTION The present invention relates to improvements in supports or carriers for textile yarn and like materials which are to be wound and unwound at high speeds without undue hazard of breakage such as may be induced by imprecise and irregular package build-up, and, in one particular aspect, to novel and improved bobbins the exteriors of which are incrementally rather than uniformly tapered, to form unique shallow steps, each of lesser depth than the diameter of yarns with which they are to be used, which will promote controlled and firmly-held emplacement of windings and yet will facilitate waste-removal operations.

As is well known in the textile machinery art, packages of yarn or other textile threads are commonly collected upon spindle-mounted cores or bobbins for further processing and dispensing, it being important that such bobbins be of predetermined external dimensions and have relatively smooth surface characteristics, that they be of relatively light weight and inexpensive, and that they lend themselves to collection and removal of yarn at very high rates without developing excessive numbers of so-called ends down (i.e., yarn breakages), slippage, shifts in position, sloughing and tangling. The bobbin and spindle assemblies which have been evolved over the course of many years in this welldeveloped art have assumed a variety of structural forms and have been fabricated of many different materials; however, the type of bobbin to which the present invention is particularly directed involves a hollow tubular element which may be slightly tapered, or coni Cally-sloped, and which may typically be made of impregnated paper, plastic, or the like. Such bobbins are generally intended to be mated rather loosely with spindles over substantially their full lengths and are slipfitted in frictionally-driven relationships with upright spindles near their upper ends. Large numbers of these bobbins are dropped, empty, onto the numerous upstanding spindles of a winding machine, after a few turns have first been wrapped manually or automatically around the base or acorn portion of each of the spindles, and the spindles are then rapidly accelerated to the very high rotational speeds which are modernly required for heightened productivity. Package build-up on each bobbin is conventionally regulated by a surrounding movable ring-traveller, which is designed to have the yarn pulled through it at an optimum angle for reduction of breakage possibilities.

Because even slight surface irregularities on bobbins can tend to disturb the yarn and cause occurrence of troublesome and costly ends down conditions, it has commonly been accepted that the external profile of a bobbin should be essentially straight along its package build-up region (i.e., essentially its full length). A notable exception appears in the case of the usual circumferential ring-like grooves or corrugations, which are distributed along the bobbin exterior, and are intended to anchor certain spaced portions of the yarn wrapped next to the bobbin surface and thereby ultimately secure the entire yarn package against axial slippage. If such grooves are too shallow, they are unable to serve the intended function, and, if of sufficient depth for such purposes, can become an unintended serious contributor to poorly-controlled formation of the yarn package and to yarn breakage and to waste-removal problems. Once the yarn packages commence build-up in an imperfectly-controlled manner, all subsequent operations, including dyeing and finishing, can be adversely affected; if yarn breakage does not actually occur, for example, the irregular tensioning and slacking of yarn, or tangling, can lead to such difficulties. In part, problems associated with conventional grooves or corrugations are thought to stem from unintended embedment or trapping of multiple turns of yarn in single grooves designed to accommodate only one turn; this is a condition which tends to arise as the normal relaxed thickness of the yarn is compressed to about half that amount under accompanying winding tension. As the usual traveller ring is raised and lowered alternately during initial winding, the tensed yarn, several wraps can fall within the contours of the grooves, and the initial build-up becomes uneven; such unevenness in turn occasions irregularities in the package as it develops, and the roots of the aforementioned problems are then well established. Specifically, the yarn may be sometimes tense and sometimes relatively slack, tangles are more likely to occur, breakage risks are heightened, and ultimate removal of waste is more difficult because of tight yarn entrapments in the grooves.

Bobbins of the type which may be improved through practice of the present invention appear in U.S. Pat. Nos. 3,321,901 and 3,167,262.

SUMMARY In accordance with the present teachings, difficulties of the aforesaid character can be very greatly reduced, with the related structural innovations being remarkably simple and inexpensive. These innovations are concerned with elimination of the usual external grooves or corrugations of a bobbin, and the substitution, instead, of numerous relatively shallow uniformlysloped steps distributed along the length of the bobbin exterior, each such step forming a riser with its neighbor which is of lesser height than the uncompressed diameter of the yarn to be used, and the pro jecting ends of the steps being aligned to form a sub-' stantially linear overall profile for the bobbin.

It is one of the objects of the present invention to provide novel and improved textile bobbins, and the like, in which inexpensive readily-shaped, and uncomplicated external surface contouring promotes controlled uniform yarn-package build-up, suppresses breakage tendencies and unwinding irregularities, and facilitates waste removals.

A further object is to provide unique incrementallytapered textile bobbins having stepped rather than grooved or corrugated exterior surfaces.

By way of a summary account of practice of this invention in one of its aspects, an elongated tubular resinimpregnated paper bobbin, such as one having a slight inward taper from bottom to top, has its generally smooth exterior shaped, by a die, into a succession of adjacent slightly-conical steps or increments, each about one-fourth inch in length and each preferably with a slight uniform taper inwardly from top to bottom (i.e., the step taper is of sense reversed from the overall taper of the bobbin). The conical steps each exhibit a riser height, at the site of meeting with an adjoining step, which is less than the cross-sectional diameter of the yarn intended to be wound upon the bobbin. Yarn entrapments and irregular lay-on during winding are unlikely, while at the same time the wraps of yarn tend to hold themselves, and the resulting yarn package, against axial slippage, while falling into place in a controlled even manner during high-speed winding; stripping of any waste remaining after unwinding is accomplished readily and without undue hazard of damage to the bobbin surfaces, because the yarn does not to lodge inaccessibly in recesses.

BRIEF DESCRIPTION OF THE DRAWING Although the features of this invention which are considered to be novel are expressed by way of the appended claims, further details as to preferred practice of the invention, as well as to further objects and ad vantages thereof, may be most readily comprehended through reference to the following description taken in connection with the accompanying drawings, wherein:

FIG. 1 provides a side view of an improved textile bobbin, inassembled relation to a drive spindle, a yarn package being outlined by dashed linework;

FIG. 2 represents an enlarged fragment of the bobbin of FIG. 1, together with linework designating tapers, and cross-sectional yarn strands; and

FIG. 3 illustrates a cross-sectioned portion of a bobbin, such as that of FIG. 1, together with scraping elements for waste removal.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The assembly appearing in FIG. 1 includes a spindle structure of a known type wherein a substantially cylindrical upright spindle is rotated about a vertical axis 5 5 by way of a whorl 6, on support bearings (not shown) carried upon the usual textile machine spinning frame with which such spindles are commonly associated. Mated about the spindle, and rotated by it, in turn, through complementary seating surfaces near the tip of the spindle, is a laminated resin-impregnated tubular paper bobbin 7, having metal end caps 8 and 9. In all respects save those which have to do with the unique stepping of its outer surfaces, bobbin 7 is generally like those known earlier, and is intended to have a package of yarn developed about it through controlled uniform-tension evenly-laid wrapping as the bobbin is rotated at high speed. Dashed linework l0 characterizes the outline of a typical yarn package, for example.

When a textile bobbin is initially donned or dropped onto a spindle for a winding operation, it should be wholly free of waste remnants from preceding windings, and should exhibit smooth non-snagging surfaces. The few turns of to-be-wound yarn which have earlier been wrapped about the base or acorn portion 11 of the spindle provide a starting hold for yarn being taken from the usual overhead supply, and, as the spindle rotates, the yarn is fed onto its exterior surfaces through a conventional lightweight metal traveller loosely fitted onto a surrounding ring which is alternately raised and lowered by the customarily-used mechanisms, to spread the wrap or lay of yarn onto the bobbin in a prescribed manner which should regulate the build-up of the yarn package. Unless the yarn being wrapped next to the bobbin is free of entrapments, and is laid only in the intended places as the winding progresses, it may at times be unduly tensed or slack, and will be more subject to the very troublesome and costincreasing breakage or ends down conditions which are so vexing to the industry. Heretofore, the smooth external surfaces of such bobbins have commonly been interrupted only by annular grooves or corrugations, into which certain of the turns of yarn should fall, with the objective of preventing axial slippage both of the pattern of the yarn sought to be wound and of the completed yarn package as a whole. However, because of the yarn tensions which can develop during winding, the yarn diameter can be reduced and more than one turn can be stressed tightly into such grooves, with the aforementioned untoward results.

In offsetting such peculiar problems, the exterior of bobbin 7 is stepped in short shallow increments, such as 7a, 7b, 7c and 7d. The illustrated bobbin is about ten inches in length; about one and one-eighth inches in outer diameter near the bottom, and has an overall taper inwardly to about a 13/16 inch outer diameter near the top; although the exterior has the aforesaid stepped characteristic, the overall bobbin taper, of about 0.025 inch per inch, is observed by the locus of the front edges of the steps along the taper line .12-12. Each of the steps, such as increments 7a 7d, is typically only about inch in length, as is designated by dimension 13, because very significantly greater lengths may not provide enough of a yarn-locating effect to assure a well-controlled winding and properlyshaped package. A length which enables the laying-on of about 50 or 60 turns of yarn per increment appears to be quite satisfactory.

The FIG. 2 enlargement of a fragment of the same bobbin shows that each step, of circular cross-section, such as step 7c, has a substantially smooth surface following a substantially linear path, i.e., has a substantially linear generatrix, such as 14-14. Taper of each step is illustrated as negative, in that it is of sense opposite to that of the taper of the overall bobbin profile line l2l2, its angle 15 being about l.5 as initially formed by a suitable die. Corresponding maximum height 16 of the riser 17 of each step is then about 0.013 inch, as initially formed. The slight negative taper is found to be appropriate when thick or only relatively-fine yarns (such as so-called 30s yarn) are to be wound; that is, each step is designed to be very slightly conical in a sense opposite to that of the configuration of the bobbin as a whole. Alternatively, for such yarns, the generatrix for each step may be substantially parallel to the longitudinal axis of the bobbin, with the result that each step is of substantially rightcylindrical outline. Thinner or finer yarns, such as socalled 60s or s yarns, are better processed using bobbins wherein the steps are frustro-conical and have a slightly positive slope of the same sense as the taper of the bobbin profile.

The aforementioned 30s yarn, when uncompressed, has a cross-sectional diameter of about 0.007 inch, and, when under maximum tensions, exhibits a much-reduced cross-section of about 0.003 inch. Optimum maximum depth, 16, of the bobbin steps is not less than about half of the compressed or minimum diameter of tensed yarn which is to be wound upon it. That relationship is illustrated for the yarn elements 18 I in FIG. 2, but it is nevertheless entirely feasible to use the same bobbin for much finer yarns with improvement in relation to operation involving prior-art grooves. Such finer yarn is designated by reference character 19, and will be seen to collect in orderly fashion upon the steps and their riser portions 17. Importantly, the steps and their risers involve no sharp depressions or reverse curvatures inviting unwanted entrapments or severe self-locking of the finer yarn, and even such yarn will tend to free itself readily from the bobbin during unwinding or waste-stripping operations. In the latter connection, the riser portions 17 are dieformed with smoothly blended contours, and their faces are wholly positively-sloped (i.e., sloped in direction the same as that of any overall taper of the bobbin, but at much steeper angles and are in excess of acuteangle relationships with the step surfaces. The surfacesloping and dimensioning of the steps, imparted by a suitable forming disc or die, will tend to reduce somewhat as the bobbin manufacture progresses, depending upon the bobbin material, resin impregnation, and the heat of baking, and may be taken into account by way of slight initial exaggerations. The maximum springback depth of each step, after the steps have been formed to an initial depth 16 and then reduced as the result of dimensional changes induced by subsequent processing in manufacture, is preferably but a few thousandths of an inch, such as 0.003 to 0.006 inch or In FIG. 3, part of a like bobbin is represented in association with waste-stripping blades or scrapers 20. When moved in the direction of bobbin taper, 21, toward the top of the bobbin, whether by manual or mechanized means, the scrapers will drive waste remnants from the bobbin, without the application of undue force which would quickly deteriorate the bobbin surfaces.

Practices here described may be employed with plastic or other bobbins, and to untapered bobbins or to those driven other than via internal top seating. Accordingly, it should be understood that the embodiment and practices specifically described and portrayed have been presented by way of disclosure, rather than limitation, and that various modifications, substitutions and combinations may be effected by those skilled in the art without departure from the spirit and scope of this invention in its broader aspects and as set forth in the accompanying claims.

What is claimed is:

1. A bobbin for textile yarns and the like having an elongated body portion of substantially circular crosssectional outline for collection and holding of a yarn package thereon, said body portion being of resinimpregnated paper and about ten inches in length and having an outer diameter of about one and one-eighth inches near said bottom, the exterior of said body portion being of incrementally-stepped configuration longitudinally thereof and involving a plurality of relatively short-length steps in end-to-end relationship along all of said body portion upon which yarns are intended to be wound, said body portion being tubular and following an inward taper in direction from bottom to top of said bobbin, said linear taper from bottom to top being about 0.025 inch per inch, the generatrix of each of said step surfaces being slightly sloped in relation to the longitudinal profile of said bobbin and said step surfaces being sloped in direction opposite to the direction of said taper, and the riser surfaces interconnecting adjoining ones of said step surfaces being relatively short and sloped in greater than acute-angle relationships to said step surfaces, the slope of said step surfaces being not in excess of a few degrees, the length of each of said step surfaces being substantially onefourth inch, all the outer ends of said step surfaces being disposed along paths defining linear toward taper of said body portion from bottom to top thereof, and said riser surfaces being smoothly contoured in interconnecting said step surfaces, all of the surfaces of said body portion being substantially smooth and uninterrupted except for said stepped configuration, and the maximum height of said riser surfaces, in direction radially, of said bobbin, being of the order of a few thousandths of an inch, whereby yarn entrapments on said bobbin exterior are avoided, controlled even winding of yarn is promoted, and waste removal is facilitated by said stepped configuration.

Claims (1)

1. A bobbin for textile yarns and the like having an elongated body portion of substantially circular cross-sectional outline for collection and holding of a yarn package thereon, said body portion being of resin-impregnated paper and about ten inches in length and having an outer diameter of about one and one-eighth inches near said bottom, the exterior of said body portion being of incrementally-stepped configuration longitudinally thereof and involving a plurality of relatively short-length steps in end-toend relationship along all of said body portion upon which yarns are intended to be wound, said body portion being tubular and following an inward taper in direction from bottom to top of said bobbin, said linear taper from bottom to top being about 0.025 inch per inch, the generatrix of each of said step surfaces being slightly sloped in relation to the longitudinal profile of said bobbin and said step surfaces being sloped in direction opposite to the direction of said taper, and the riser surfaces interconnecting adjoining ones of said step surfaces being relatively short and sloped in greater than acute-angle relationships to said step surfaces, the slope of said step surfaces being not in excess of a few degrees, the length of each of said step surfaces being substantially one-fourth inch, all the outer ends of said step surfaces being disposed along paths defining linear toward taper of said body portion from bottom to top thereof, and said riser surfaces being smoothly contoured in interconnecting said step surfaces, all of the surfaces of said body portion being substantially smooth and uninterrupted except for said stepped configuration, and the maximum height of said riser surfaces, in direction radially, of said bobbin, being of the order of a few thousandths of an inch, whereby yarn entrapments on said bobbin exterior are avoided, controlled even winding of yarn is promoted, and waste removal is facilitated by said stepped configuration.

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