US3095161A - Anti-sloughing bobbin - Google Patents

Description

June 25, 1963 R. ATWOOD ETAL 3,095,161

ANTI-SLOUGHING BOBBIN Filed Aug. 1, 1957 FIG. 3.

GROOVE INVENTORS fl n-o1 a130 M 4. a dz y United States Patent 3,095,161 ANTI-SLOUGHING BOBBIN Rawson Atwood, Rumson, and Charles C. LAllemand, Murray Hill, NJ. Filed Aug. 1, 1957, Ser. No. 675,739 1 Claim. (Cl. 242-159) This invention relates to improvements in textile bobbins.

More particularly, the invention is concerned with providing an improved bobbin surface which minimizes sloughing or axial movement of yarn along the bobbin as it is being wound.

A bobbin embodying the invention in a preferred form will now first be described with reference to the accompanying drawing, the features forming the invention will then be pointed out in the appended claim.

In the drawing:

FIG. 1 is a side elevation of a bobbin embodying the invention in a preferred form;

FIG. 2 is an end elevation of the bobbin of FIG. 1;

FIG. 3 is an axial section of the bobbin of FIG. 1;

FIG. 4 is a much enlarged developed elevation view of a part of the surface of the bobbin, generally within the area indicated by the circle 4-4-4 of FIGURE 1; and

FIG. 5 is a section on the line 55 of FIG. 4.

The improvement of the invention is applicable to bobbins with a great variety of surfaces, structures, sizes and proportions. However, for definiteness and by way of example, the bobbin is shown herein with some completeness.

Referring to FIGS. 1-3, inclusive, the bobbin illustrated is generally of the type shown in our previous application Serial No. 494,405, filed March 15, 1955, now Patent No. 2,953,317, for Spool. The bobbin comprises an inner barrel member 1, which may be of sheet steel or other material possessing the required strength, a drive end fitting 2, a top end fitting 3 and a plastic outer barrel or covering 4. The major part of the outer surface of the barrel is, however, specially constructed or treated over the shaded area 5 to minimize sloughing or axial move- [HlBIlt of the yarn. While sloughing creates more of a problem in the lower deniers and in filaments such as nylon, the invention has been found to be of utility within a denier range of 15 or even lower, up to 70 denier or even higher, and is of utility w'thout regard to the specific ma terial of which the filament or yarn may be composed, and wherever difiiculty due to sloughing is experienced.

The cover 4 of the spool illustrated is roughened or ridged over the area 5 in a manner so as not to interfere with the winding or unwinding of the yarn, while preventing axial slippage. The preferred form of surface roughening is shown on a much enlarged scale in FIGS. 4 and 5. As there shown, the surface of the bobbin is circumferentially microgrooved. In the specific embodiment shown, the groove takes the form of a helix having an axial pitch or spacing between grooves of about 128 to the inch, so that the indicated distance is in the neighborhood of .008 inch. The groove itself may vary in dimensions, but it has been found in practice that a groove having a depth of about .002 or even less is satisfactory. A microgroove of this type does not disturb the desirable surface characteristics of the bobbin in any way and efiec- 3,095,161 Patented June 25, 1963 ice tively prevents any objectionable sloughing or axial movement of the yarn.

The invention in its broader aspect is not limited to any particular construction of bobbin, as for example, to a bobbin composed of metal inner barrel with plastic covering, but is applicable also to molded or turned bobbins made of any of various materials, provided they may be suitably microgrooved either by cutting, molding or pressing the groove in the surface of the bobbin.

In the particular bobbin shown by way of example, the plastic cover is composed of an acrylonitrile copolymer such as marketed under the trade name Kralastic, although a variety of other thermoplastic or thermosetting resins may be employed. With this material, the cover 4 may conveniently be manufactured in the form of tubing and the microgroove may be pressed into the surface by means of a suitably grooved metal die.

The precise size and pitch of the microgroove may be selected with reference to the manufacturing processes employed to produce it, the characteristics of the material of which the bobbin surface is composed and the class of service for which the bobbin is used. It will be noted that the size of the groove may be and preferably is very small with reference to even very fine yarns, as even 15 denier filament has a diameter of about 1.7 mills, while 60 denier filament has a diameter of about 3.4 mills. In general, the pitch or axial spacing between adjacent grooves is at least equal to and preferably is two to four times the thickness of the filament, while the groove itself has a depth and width which may be a very small fraction of even a very fine yarn or filament diameter. For example, a groove at a depth of .0002 has a depth and width amounting to only about 15% of the diameter of even a fine filament such as 15 denier nylon. In general, grooving having a depth in a range from about .0001 to .001" can be manufactured in a practical manner and furnish resistance to sloughing while not interfering with winding the yarn. In consequence, the characteristics of the bobbin so far as winding and unwinding of the yarn are concerned are practically unafiected and the surface is to all intents and purposes a smooth one. However, the grooving presents sufficient resistance to axial movement of yarn in contact with the bobbin surface to prevent sloughing in a very effective manner.

The preferred method of microgrooving the bobbin surface consists in placing the plastic cover tube in a cavity die having a sharp V-thread of the desired pitch, in the case illustrated by way of example, 128 threads to the inch, and expanding the plastic tube outwardly against the cavity die under a pressure of 3,000 6 ,000 psi The cover tube of the indicated acrylonitrile plastic and the wall thickness of .02. inch may be indented in this manner very readily. Under these conditions, there may be an indicated bite of the thread into the outer surface of the plastic of about one-half a thousandth of an inch, resulting in a groove of somewhat less than this depth and depending upon the amount of spring back. The size of the groove, for practical purposes, is not readily measurable, but production may be controlled by the use of an ordinary profilometer, even though the indicated groove depth obtained from such an instrument may be a rather arbitrary figure. For example, it has been found that a satisfactory bobbin surface will give a profilometer reading of (.51 about 20-40 micro inches (R.M.S.), using a conical Stylus with .0005 radius tip, Where an ungrooved bobbin of similar construction and surface material will give a profilometer reading of about 4 micro inches (R.M.S.)

Without departing from the invention in its broader aspect, the grooving may extend over the entire surface of the bobbin, although preferably the end areas upon which no yarn is Wound are left smooth and ungrooved, as indicated in the drawing.

What is claimed is:

A textile package comprising a bobbin and yarn wound thereon, the bobbin having a yarn Winding surface comprising a microgroove indented in the bobbin surface, the

4 pitch of the groove being a small multiple of the yarn diameter and the depth and width of the groove being a fraction of the yarn diameter, the yarn thickness being in a range from about 15 denier to about 70 denier, the groove spacing being about .008 and the groove depth being in a range from about .0001" to .091".

References Cited in the file of this patent UNITED STATES PATENTS

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