Abstract:
Continuously connected fastener stock and a method of making same. The method, in one embodiment involves providing a rotating molding wheel, the wheel being provided with a peripheral impression comprising a pair of peripherally-extending side members interconnected by a plurality of cross-links. Molten plastic is extruded into the peripheral impression of the wheel, with a layer of controlled film overlying the peripheral impression. The molten plastic is then allowed to solidify. A knife in substantially elliptical contact with the peripheral impression is then used to skive excess plastic from the rotating molding wheel. The knife is provided with a pair of cut-out portions along its bottom edge, each cut-out portion being aligned with one of the peripherally-extending side members so as to augment the transverse cross-sectional size thereof. The continuously connected fastener stock thus formed is then removed from the rotating molding wheel. The fastener stock includes in one embodiment first and second side members each being generally circular in cross-section and a plurality of cross-links each having a flat surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    The present application is a continuation-in-part of U.S. patent application Ser. No. 09/904,173, inventors Thomas Shilale and William J. Cooper, filed Jul. 12, 2001, the disclosure of which is incorporated herein by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates generally to plastic fasteners of the type that are adapted, for example, to attach tags to articles of commerce and relates more particularly to a novel method of manufacturing a plurality of said plastic fasteners as continuously connected fastener stock, to the continuously connected fastener stock thus made, to individual fasteners derived from said continuously connected fastener stock and to needles designed for use with said continuously connected fastener stock.  
           [0003]    Plastic fasteners of the type comprising an elongated flexible filament having a first cross-bar at one end and a second cross-bar (or other enlargement, such as a paddle or a knob) at the opposite end are well-known and have been widely used in a variety of applications, such as in the attachment of merchandise tags to articles of commerce, in the attachment of buttons to garments, in the lasting of shoes, and in various packaging applications. Typically, such plastic fasteners are mass-produced by molding processes into either one of two different types of assemblies. One such assembly, an example of which is disclosed in U.S. Pat. No. 3,103,666, inventor Bone, issued Sep. 17, 1963 (which patent is incorporated herein by reference), is a clip-type assembly, said clip comprising a plurality of fasteners, each such fastener comprising a flexible filament having a first cross-bar at one end thereof and a paddle or second cross-bar at the opposite end thereof. The fasteners are arranged in a spaced, side-by-side orientation, with the respective first cross-bars parallel to one another and the respective paddles or second cross-bars parallel to one another, each of the first cross-bars being joined to a common, orthogonally-disposed runner bar by a severable connector. Adjacent second cross-bars or paddles also maybe interconnected by severable connectors extending therebetween.  
           [0004]    The aforementioned fastener clip is typically made by injection molding. Several commercial embodiments of the above-described fastener clip have been sold by the present assignee, Avery Dennison Corporation, as DENNISON® SWIFTACH® fastener clips.  
           [0005]    A second type of fastener assembly is known as continuously connected fastener stock. In one type of continuously connected stock, the fastener stock is formed from two elongated, uniform and continuous side members coupled together by a plurality of cross-links equidistantly-spaced apart by a distance of 0.25 inch. Individual fasteners having an H-shape, often referred to as “plastic staples,” are dispensed from the fastener stock by cutting the side members at appropriate points between cross-links, thereby yielding individual fasteners having cross-bars of 0.25 inch in length. In another type of continuously connected stock, the fasteners comprise a flexible filament having a cross-bar at one end thereof and a paddle (or second cross-bar) at the opposite end thereof, the respective cross-bars and paddles of successive fasteners being arranged end-to-end and being joined together by severable connectors to form continuous, albeit non-uniform, side members.  
           [0006]    An example of continuously connected fastener stock is disclosed in U.S. Pat. No. 4,039,078, inventor Bone, issued Aug. 2, 1977 (which patent is incorporated herein by reference). In said patent, the continuously connected fastener is described as being made by one of two different methods. The first of said two methods comprises extruding a continuous strip of plastic and then punching out or forming apertures in the strip in such a way as to leave only the side members and the cross-links in the strip, said side members and said cross-links being rectangular in cross-section. The other of said two methods comprises injection molding two or more separate lengths of the fastener stock and then joining together the lengths by applying heat to weld the respective side members together, said side members and said cross-links being circular in cross-section.  
           [0007]    Neither of the two methods described above has received much, if any, commercial use in the manufacturing of continuously connected fastener stock.  
           [0008]    Another example of continuously connected fastener stock is described in U.S. Pat. No. 4,462,784, inventor Russell, issued Jul. 31, 1984 (which patent is incorporated herein by reference). In said patent, the continuously connected fastener stock is made by a rotary extrusion process that involves the use of a rotating molding wheel whose periphery is provided with molding cavities that are complementary in shape to the molded fastener stock. To form fasteners, plastic is extruded into the cavities of the molding wheel, and a knife in substantially elliptical contact with the wheel is used to skive excess plastic from the molding wheel, leaving plastic only in the molding cavities. Following molding, the filament portions of the fasteners are typically stretched.  
           [0009]    The aforementioned rotary extrusion technique has been used extensively by the present assignee in the manufacturing of continuously connected fastener stock. As can readily be appreciated, some advantages of the above-described rotary extrusion technique, as compared to the injection molding/welding technique described above, are that virtually any length of fastener stock can be obtained and that the post-molding welding step is eliminated.  
           [0010]    However, one consequence of the rotary extrusion process described above, particularly the skiving step thereof, is that the first cross-bar, the filament, and the second cross-bar (or paddle) of each fastener are all flat on one side thereof, with the flattened sides of the first cross-bar, the filament and the second cross-bar all lying in the same plane (see e.g., FIG. 1B of U.S. Pat. No. 4,462,784). The other surfaces of the first-cross bar, the filament, and the second cross-bar (or paddle) conform to the shapes of the molding cavities and are typically not flat. For example, the other surface of the cross-bar (and the filament) is typically curved, thereby resulting in a cross-bar (and a filament) whose transverse cross-section has a shape resembling a semicircle or semi-ellipse. This property of the continuously connected stock of U.S. Pat. No. 4,462,784 of being shaped so as to be flat on only one side is apparently not shared by the continuously connected fastener stock of U.S. Pat. No. 4,039,078.  
           [0011]    Tools (often referred to as “tagging guns” or “fastener attaching tools”) for dispensing individual fasteners from continuously connected fastener stock above are known, examples of such tools being disclosed in the following U.S. patents, all of which are incorporated herein by reference: U.S. Pat. No. 4,039,078, inventor Bone, which issued Aug. 2, 1977; U.S. Pat. No. 5,433,366, inventors Deschenes et al., which issued Jul. 18, 1995; U.S. Pat. No. 4,121,487, inventor Bone, which issued Oct. 24, 1978; U.S. Pat. No. 5,320,269, inventors Deschenes et al., which issued Jun. 14, 1994; U.S. Pat. No. 4,955,475, inventors McCarthy et al., which issued Sep. 11, 1990; U.S. Pat. No. 4,456,161, inventor Russell, which issued Jun. 26, 1984; U.S. Pat. No. 5,024,365, inventor Bourque, which issued Jun. 18, 1991; and U.S. Pat. No. 4,998,661, inventors Deschenes et al., which issued Mar. 12, 1991.  
           [0012]    Such tools typically comprise a needle, the needle typically including a stem portion. The stem portion typically is generally cylindrical in shape and has a longitudinally-extending, cylindrically-shaped bore adapted to receive the first cross-bar of a fastener. In addition, said stem portion also typically has a longitudinally-extending slot adapted to permit the filament portion of a fastener to extend therethrough while the first cross-bar of the fastener is disposed in the longitudinal bore of the stem portion. The stem portion also typically has a tip adapted for insertion into a desired article of commerce. The needle also may include a base portion, said base portion being attached to the rear of the stem portion and being adapted to be removably received in the tool. The stem portion and the base portion may be a unitary structure or, as is more often the case, the base portion is insert-molded onto the rear end of the stem portion.  
           [0013]    Such tools also typically comprise an ejector rod for ejecting a first cross-bar from the needle and into the article of commerce and may also include a knife or similar severing means for cutting the severable connector between the first cross-bar being dispensed and its adjacent first cross-bar and feeding means for advancing the assembly of fasteners in the tool so as to align the forwardmost first cross-bar with the needle.  
           [0014]    It has been found by the inventors that the dispensing of continuously connected fastener stock of the type described in U.S. Pat. No. 4,462,784 through needles of the type described above in which the longitudinal bore and the longitudinal slot together have a symmetric transverse cross-sectional shape resembling an inverse lollipop (the longitudinal bore being circular in transverse cross-section, the longitudinal slot being rectangular in transverse cross-section and bisecting said longitudinal bore at the top thereof) introduces two significant drawbacks.  
           [0015]    As a first drawback, the dispensing of fastener stock through the needle of a fastener dispensing tool in which the cross-bar and filament of the individual fasteners collectively have a “d” shape in lateral cross-section and in which the longitudinal bore of the needle is circular in lateral cross section can cause the fastener dispensing tool to malfunction. Specifically, because a considerable portion of the transverse cross-sectional area of the bore is not occupied by the cross-bar, proper engagement of the cross-bar by the ejector rod and proper translational movement of the cross-bar through the length of the bore due to action of the ejector rod is not always achieved, which is highly undesirable.  
           [0016]    As a second drawback, the dispensing of fastener stock through the needle of a fastener dispensing tool in which the cross-bar and filament of the individual fasteners collectively have a “d” shape in lateral cross-section and in which the longitudinal bore of the needle is circular in lateral cross-section creates a considerable amount of unused space within the needle. This considerable amount of unused, or wasted, space within the needle serves to significantly increase the diameter of the needle. As can be appreciated, an increase in the size of the needle serves to increase the size of the corresponding insertion hole which is formed in the fastened article by the needle, which is highly undesirable.  
         SUMMARY OF THE INVENTION  
         [0017]    It is an object of the present invention to provide a new method of manufacturing continuously connected fastener stock.  
           [0018]    It is another object of the present invention to provide a method as described above that overcomes at least some of the problems described herein that are associated with existing methods for manufacturing continuously connected fastener stock.  
           [0019]    According to one aspect of the invention, there is provided a method of manufacturing continuously connected fastener stock, said method comprising the steps of:  
           [0020]    (a) providing a rotating molding wheel, said rotating molding wheel being provided with a peripheral impression comprising a pair of peripherally-extending side members interconnected by a plurality of cross-links;  
           [0021]    (b) extruding molten plastic into the peripheral impression of said rotating molding wheel, with a layer of controlled film overlying the peripheral impression;  
           [0022]    (c) allowing the molten plastic to solidify;  
           [0023]    (d) using a knife in substantially elliptical contact with the peripheral impression to skive excess plastic from the rotating molding wheel, said knife having a bottom provided with a first cut-out portion aligned with one of said peripherally-extending side members so as to augment the transverse cross-sectional size thereof; and  
           [0024]    (e) removing the continuously connected fastener stock thus formed from the rotating molding wheel.  
           [0025]    Preferably, the peripheral impression is formed around the entire periphery of the rotating molding wheel, and the bottom of said knife is further provided with a second cut-out portion aligned with the other of said peripherally-extending side members so as to augment the transverse cross-sectional size thereof.  
           [0026]    In one embodiment, each of the peripherally-extending side members of said peripheral impression is generally uniform and semi-elliptical in transverse cross-section, each of said cross-links of said peripheral impression is generally semi-circular in transverse cross-section, and each of said first and second cut-out portions is complementarily shaped relative to its respective peripherally-extending side member of said peripheral impression so that each cross-link of the continuously connected fastener stock symmetrically bisects the side members of the continuously connected fastener stock.  
           [0027]    In another embodiment, each of said peripherally-extending side members of said peripheral impression is generally rectangular in transverse cross-section, each of said cross-links of said peripheral impression is generally semi-circular in transverse cross-section, and each of said first and second cut-out portions is complementarily shaped relative to its respective peripherally-extending side member of said peripheral impression so that each cross-link of the continuously connected fastener stock symmetrically bisects the side members of the continuously connected fastener stock.  
           [0028]    In yet another embodiment, each of said peripherally-extending side members of said peripheral impression is generally semi-circular in transverse cross-section and each of said cross-links of said peripheral impression is generally semi-circular in transverse cross-section, with the flat surfaces of the side member impressions lying flush with the flat surfaces of the cross-link impressions and with the curved surfaces of the side member impressions lying flush with the curved surfaces of the cross-link impressions. In addition, each of said first and second cut-out portions is semi-circular in transverse cross-section so that the side members of the continuously connected fastener stock are circular in transverse cross-section, with each cross-link of the continuously connected fastener stock asymmetrically bisecting the side members of the continuously connected fastener stock.  
           [0029]    In still another embodiment, each of said peripherally-extending side members of said peripheral impression is generally semi-circular in transverse cross-section and is shaped to include a pair of opposing sloped surfaces, and each of said cross-links of said peripheral impression is generally semi-circular in transverse cross-section, the flat surfaces of said side member impressions lying flush with the flat surfaces of said cross-link impressions, the arcuate surfaces of said side member impressions extending beyond the arcuate surfaces of said cross-link impressions. In addition, each of said first and second cut-out portions is complementarily shaped relative to its respective peripherally-extending side member of said peripheral impression so that the side members of the continuously connected fastener stock are circular in transverse cross-section, with each cross-link of the continuously connected fastener stock asymmetrically bisecting the side members of the continuously connected fastener stock.  
           [0030]    The present invention is also directed to a length of continuously connected fastener stock fabricated according to the above-described method and to individual fasteners derived from said continuously connected fastener stock.  
           [0031]    Therefore, according to another aspect of the invention, there is provided a length of continuously connected fastener stock, said length of continuously connected fastener stock comprising (a) first and second side members; and (b) a plurality of cross-links interconnecting said first and second side members, each of said cross-links having a flat surface and an arcuate surface; (c) wherein said first side member is shaped to extend transversely beyond said flat surface.  
           [0032]    According to still another aspect of the invention, there is provided a length of continuously connected fastener stock, said length of continuously connected fastener comprising (a) first and second side members; and (b) a plurality of cross-links interconnecting said first and second side members, each of said cross-links having a flat surface; (c) wherein said first side member is shaped to extend transversely beyond said flat surface with an arcuate surface.  
           [0033]    According to a further aspect of the invention, there is provided a needle for use in a plastic fastener dispensing tool which is sized to have an overall diameter smaller than a conventional needle.  
           [0034]    Additional objects, features, aspects and advantages of the present invention will be set forth, in part, in the description which follows and, in part, will be obvious from the description or may be learned by practice of the invention. In the description, reference is made to the accompanying drawings which form a part thereof and in which is shown by way of illustration specific embodiments for practicing the invention. These embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0035]    The accompanying drawings, which are hereby incorporated into and constitute a part of this specification, illustrate preferred embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings wherein like reference numerals represent like parts:  
         [0036]    [0036]FIG. 1 is a perspective view of a length of continuously connected fastener stock of the plastic staple variety fabricated using the conventional rotary extrusion technique;  
         [0037]    [0037]FIG. 2 is an enlarged end view of an individual plastic staple obtained from the length of conventional continuously connected fastener stock of FIG. 1;  
         [0038]    [0038]FIG. 3 is a top view of a conventional needle adapted for use in dispensing fasteners, such as the plastic staple of FIG. 2;  
         [0039]    [0039]FIG. 4 is a left side view of the needle shown in FIG. 3;  
         [0040]    [0040]FIG. 5 is a front view of the stem portion of the needle shown in FIG. 3;  
         [0041]    [0041]FIG. 6 is a transverse section view of the stem portion of the needle of FIG. 3, the plastic staple of FIG. 2 being disposed therewithin;  
         [0042]    [0042]FIG. 7 is a perspective view of a first embodiment of a length of plastic staple stock constructed according to the teachings of the present invention;  
         [0043]    [0043]FIG. 8 is an end view of the length of plastic staple stock shown in FIG. 7;  
         [0044]    [0044]FIG. 9 is an enlarged side view of an individual plastic staple obtained from the length of plastic staple stock of FIG. 7;  
         [0045]    FIGS.  10 ( a ) and  10 ( b ) are side and perspective views, respectively, of a first embodiment of a skiving knife constructed according to the teachings of the present invention;  
         [0046]    FIGS.  11 ( a ) and  11 ( b ) are side and perspective views, respectively, of a second embodiment of a skiving knife constructed according to the teachings of the present invention;  
         [0047]    [0047]FIG. 12 is an end view of a second embodiment of a length of plastic staple stock constructed according to the teachings of the present invention;  
         [0048]    [0048]FIG. 13 is a fragmentary front view of the length of plastic staple stock shown in FIG. 12.  
         [0049]    [0049]FIG. 14 is an enlarged fragmentary end view of a third embodiment of a length of plastic staple stock constructed according to the teachings of the present invention;  
         [0050]    [0050]FIG. 15 is a transverse section view of the stem portion of the needle of FIG. 3, with an individual fastener from the plastic staple stock of FIG. 14 being disposed therewithin;  
         [0051]    [0051]FIG. 16 is an end view of a fourth embodiment of a length of plastic staple stock constructed according to the teachings of the present invention;  
         [0052]    [0052]FIG. 17 a side view of an individual plastic staple obtained from the length of plastic staple stock of FIG. 16;  
         [0053]    FIGS.  18 ( a ) and  18 ( b ) are side and perspective views, respectively, of a third embodiment of a skiving knife constructed according to the teachings of the present invention;  
         [0054]    [0054]FIG. 19 is an end view of a fifth embodiment of a length of plastic staple stock constructed according to the teachings of the present invention;  
         [0055]    [0055]FIG. 20 is a side view of an individual plastic staple obtained from the length of plastic staple stock of FIG. 19;  
         [0056]    [0056]FIG. 21 is an enlarged fragmentary end view of the length of plastic staple stock of FIG. 19;  
         [0057]    [0057]FIG. 22 is a transverse section view of the stem portion of a needle constructed according to the teachings of the present invention; and  
         [0058]    [0058]FIG. 23 is a section view showing an individual fastener from the fastener stock of FIG. 19 within the stem portion of the needle of FIG. 22.  
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0059]    Referring now to FIG. 1, there is shown a perspective view of a length of continuously connected fastener stock of the plastic staple variety that has been fabricated using the conventional rotary extrusion technique described above, said length of fastener stock being represented generally by reference numeral  11 .  
         [0060]    Fastener stock  11 , which is typically made of polyurethane, comprises two elongated, uniform and continuous side members  13 - 1  and  13 - 2 . Side members  13 - 1  and  13 - 2  are coupled together by a plurality of flexible cross-links or filaments  15 , cross-links  15  being equidistantly-spaced apart by a distance of 0.25 inch. By cutting side members  13 - 1  and  13 - 2  at appropriate points between cross-links  15 , individual fasteners having an H-shape, often referred to as “plastic staples,” are produced. Each of the cross-bars of an individual plastic staple has a length of 0.25 inch.  
         [0061]    Referring now to FIG. 2, there is shown an enlarged end view of an individual plastic staple obtained in the aforementioned manner from a length of fastener stock  11 , the individual plastic staple being represented generally by reference numeral  21 .  
         [0062]    Staple  21  comprises a first cross-bar  23 - 1 , which has been cut from side member  13 - 1 , and a second cross-bar  23 - 2 , which has been cut from side member  13 - 2 , cross-bars  23 - 1  and  23 - 2  being interconnected by flexible filament  15 . As can be seen, due to the conventional rotary extrusion process by which stock  11  is formed, cross-bars  23 - 1  and  23 - 2  and filament  15  are flat on sides  25 - 1 ,  25 - 2  and  25 - 3 , respectively, sides  25 - 1 ,  25 - 2  and  25 - 3  being coplanar with one another. (The remaining surfaces of filament  15  and cross-bars  23 - 1  and  23 - 2  are curved.) As a result, as can be seen, cross-bar  23 - 1  and filament  15  collectively have a generally “d”-shape when viewed from an end, with cross-bar  23 - 1  having a substantially semi-oval shape in cross-section. Cross-bar  23 - 1  has a transverse width Tw 1  greater than its transverse length Tl 1 . Filament  15  has a width w 1 . Cross-bar  23 - 2  and filament  15  also collectively have a generally “d”-shape when viewed from an end, with cross-bar  23 - 2  being sized and shaped identically to cross-bar  23 - 1 .  
         [0063]    Referring now to FIGS. 3 and 4, there are shown top and left side views, respectively, of a conventional needle adapted for use in dispensing fasteners, such as the plastic staple of FIG. 2, said needle being represented generally by reference numeral  51 .  
         [0064]    Needle  51  comprises a stem portion  53  and abase portion  55 . Stem portion  53  may be made, for example, by stamping and rolling or by machining a piece of metal (e.g., stainless steel) or by the electroforming/machining technique described in U.S. Pat. No. 5,489,057, inventor Deschenes, issued Feb. 6, 1996, the disclosure of which is incorporated herein by reference.  
         [0065]    Referring now to FIGS. 3 through 5, stem portion  53  can be seen to be an elongated member that is substantially cylindrical over most of its length (and annular in transverse cross-section). The front end of stem portion  53  is formed into a spoon-shaped tip  57 , tip  57  being sufficiently sharp to enable its penetration into a desired article of commerce. A generally cylindrical bore  59  extends longitudinally across substantially the entire length of stem portion  53 . Bore  59  is appropriately dimensioned to receive a cross-bar of a plastic fastener, such as cross-bar  23 - 1  of plastic staple  21 . Stem portion  53  is also shaped to include a slot  61  extending longitudinally across substantially the entire length of stem portion  53 , slot  61  being appropriately dimensioned to permit a filament, such as filament  15 , to extend therethrough while its associated cross-bar is disposed within bore  59 .  
         [0066]    A conventional stamped and rolled stainless steel stem portion  53  used in the dispensing of plastic staples  21  typically has a width w 1  of about 0.068 inch, a cross-sectional thickness t 1  of about 0.013-0.0165 inches, and an inside diameter I d  of about 0.037-0.040 inches.  
         [0067]    Referring back to FIGS. 3 and 4, base portion  55  is made in the conventional manner by insert-molding plastic onto the rear end  60  of stem portion  53 . Base portion  55 , which is generally cylindrical in shape, includes a generally cylindrically-shaped longitudinal bore aligned with (and sized similarly to) bore  59  of stem portion  53  and also includes a longitudinal slot aligned with (and sized similarly to) slot  61  of stem portion  53 . Base portion  55  is provided with a recessed area  63  for use in correctly positioning needle  51  within a fastener dispensing tool and for locking the same into place.  
         [0068]    Referring now to FIG. 6, there is shown a transverse section view of stem portion  53 , with plastic staple  21  being loaded therein. As described above, the present inventors have noted that, because filament  15  and cross-bar  23 - 1  are flat on sides  25 - 3  and  25 - 1 , respectively, whereas bore  59  is circular in transverse cross-section and slot  61  bisects bore  59  from the top thereof, a considerable portion ofbore  59  is left unoccupied by staple  21 . Consequently, because cross-bar  23 - 1  is much smaller than bore  59  and has considerable freedom to move laterally within bore  59 , the proper translational movement of cross-bar  23 - 1  through bore  59  during ejection cannot be assured. Furthermore, because cross-bar  23 - 1  is much smaller than bore  59 , the overall diameter of needle  51  is unnecessarily large, which is highly undesirable.  
         [0069]    Referring now to FIGS. 7 and 8, there are shown perspective and end views, respectively, of a length of continuously connected fastener stock of the plastic staple variety that has been fabricated in accordance with the teachings of the present invention, said length of fastener stock being represented generally by reference numeral  101 .  
         [0070]    Fastener stock  101  is similar in many respects to fastener stock  11 , fastener stock  101  comprising a pair of elongated, uniform and continuous side members  103 - 1  and  103 - 2  that are coupled together by a plurality of flexible cross-links  105  equidistantly-spaced apart by a distance of 0.25 inch. (It should be understood that the distance between adjacent cross-links  105  need not be 0.25 inch and may be, for example, about 0.18 inch. Such a modification in cross-link spacing would, however, require the use of a molding wheel having a correspondingly formed impression. A pitch of about 0.18 inch is believed by the present inventors to be preferred over a pitch of 0.25 inch in that a greater number of fasteners can be formed over a given length. A pitch smaller than about 0.18 inch is believed by the present inventors to have the disadvantage of resulting in a cross-bar that too easily deforms (i.e. “Y-s”) when a pulling force is applied to the filament connected to the cross-bar. This problem is exacerbated where the stock is made of a material, like urethane, that is flexible.) An individual plastic fastener  102  that has been cut from fastener stock  101  is shown separately in FIG. 9 and can be seen to include a pair of cross-bars  104 - 1  and  104 - 2  interconnected by a cross-link  105 .  
         [0071]    As seen best in FIG. 8, fastener stock  101  differs significantly from fastener stock  11  in that side members  103 - 1  and  103 - 2  do not have a flat side. (Cross-link  105 , however, does have a flat side  106  that is similar to side  25 - 3  of filament  15 .) Instead, side members  103 - 1  and  103 - 2  are elliptical in transverse cross-section, with cross-links  105  symmetrically bisecting side members  103 - 1  and  103 - 2 .  
         [0072]    One of the advantages of stock  101 , as compared to stock  11 , is that side members  103  (and the individual cross-bars derived therefrom) have a cross-sectional transverse shape that corresponds more closely to that of bore  59  of needle  51  than do side members  13 . (Some proportional scaling down of the cross-sectional size of members  103  may be needed to permit the generally elliptically-shaped cross-bars derived from member  103  to fit properly within circularly-shaped bore  59 .) Consequently, improved engagement of the cross-bar by the ejector rod and improved translational movement of the cross-bar through the length of bore  59  is made possible.  
         [0073]    Fastener stock  101  may be fabricated by the conventional rotary extrusion method used to make stock  11 , with one notable exception. Instead of being made using a conventional skiving knife, which has a straight bottom surface or edge (hence, flat sides  25 - 1 ,  25 - 2  and  25 - 3  of fastener stock  11 ), fastener stock  101  is made using the skiving knife of FIGS.  10 ( a ) and  10 ( b ), said skiving knife being constructed in accordance with the teachings of the present invention and being represented generally by reference numeral  111 .  
         [0074]    As can be seen best in FIG. 10( b ), knife  111  includes a bottom edge  113 , bottom edge  113  being provided with a pair of cut-away portions  115 - 1  and  115 - 2 , cut-away portions  115 - 1  and  115 - 2  being appropriately spaced apart to permit their alignment with the impressions used to make side members  13 - 1  and  13 - 2 , respectively. In the present embodiment, cut-away portions  115 - 1  and  115 - 2  are complementarily shaped relative to side members  13 - 1  and  13 - 2 , respectively, so that filament  105  symmetrically bisects side members  103 - 1  and  103 - 2 . It should be understood, however, that cut-away portions  115 - 1  and  115 - 2  need not be shaped in this manner and may assume virtually any shape. For example, cut-away portions  115 - 1  and  115 - 2  may be shaped to match the transverse cross-sectional shape of side members  13 - 1  and  13 - 2 , respectively, so that the filament of the resultant fastener stock asynmmetrically bisects the side members. It should also be understood that one of cut-away portions  115 - 1  and  115 - 2  could be eliminated entirely if one wished to provide only one of side members  13 - 1  and  13 - 2  with a non-flat geometry. This may be desirable, for example, where the continuously connected fastener stock is not of the plastic staple variety, but rather, is of the type wherein one of the side members is shaped to include a plurality of cross-bars interconnected end-to-end by severable connectors and the other of the side members is shaped to include a plurality of paddles interconnected end-to-end by severable connectors.  
         [0075]    Referring now to FIGS.  11 ( a ) and  11 ( b ), there are shown side and perspective views, respectively, of a second embodiment of a skiving knife constructed according to the teachings of the present invention, said skiving knife being represented generally by reference numeral  201 .  
         [0076]    As seen best in FIG. 11( b ), skiving knife  201  is similar in many respects to skiving knife  111 , the principal difference between the two knives being that skiving knife  201  is provided with a bottom edge  203  having a pair of rectangular cut-away portions  205 - 1  and  205 - 2 , as compared to the arcuate cut-away portions  115 - 1  and  115 - 2  of knife  111 . Knife  201  is adapted for, but is not limited to, use in combination with a modified molding wheel whose side member impressions are rectangular, as opposed to semi-elliptical, in transverse cross-section and whose cross-link impressions include a rounded surface. An example of a length of plastic staple stock fabricated using knife  201  and a molding wheel as described above is shown in FIGS. 12 and 13, said length of stock being represented generally by reference numeral  251 . Stock  251  comprises a pair of side members  253 - 1  and  253 - 2  of rectangular transverse cross-section interconnected by a plurality of equidistantly-spaced cross-links  255  of a truncated cylindrical or semi-cylindrical transverse cross-section.  
         [0077]    Stock  251  may be used with needle  51 , with some proportional scaling down of the cross-sectional size of members  253  possibly being needed to permit the cross-bars derived from members  253  to fit properly within bore  59 . Alternatively, a needle having a rectangularly-shaped bore may be used, instead of needle  51 , with stock  251 .  
         [0078]    Although cross-links  255  symmetrically bisect side-members  253 - 1  and  253 - 2  in the embodiment shown, it can readily be appreciated that, by modifying the size and/or shape of cut-away portions  205 - 1  and  205 - 2 , a length of fastener stock can be obtained in which cross-links  255  asymmetrically bisect the resultant side members. Furthermore, it should be understood that fastener stock having side members of a variety of alternative transverse cross-sectional shapes can be obtained by appropriately shaping the side member impressions in the molding wheel and the cutaway portions in the skiving knife.  
         [0079]    Specifically, referring now to FIG. 14, there is shown an enlarged fragmentary end view of another embodiment of a length of continuously connected fastener stock of the plastic staple variety that has been fabricated in accordance with the teachings of the present invention, said length of fastener stock being represented generally by reference numeral  271 .  
         [0080]    Fastener stock  271  is similar in many respects to fastener stock  101 , fastener stock  271  comprising a pair of elongated, uniform and continuous side members  273  (only one of said pair of side members  273  being shown, the other of said pair of side members being a mirror image thereof) that are coupled together by a plurality of flexible, equidistantly-spaced cross-links  275 . Preferably, cross-links  275  are spaced apart by a distance of 0.18 inch to yield individual fasteners whose cross-bars have a length of 0.18 inch. Fastener stock  271 , like fastener stock  101 , is preferably made of urethane.  
         [0081]    Fastener stock  271  differs notably from fastener stock  101  in that the cross-sectional shape of side members  273  is generally circular, as opposed to the generally elliptical shape of side members  103 . In addition, each of side members  273  is shaped to include an outer flattened surface  277  and an inner flattened surface  279 , surfaces  277  and  279  being angled in opposing directions. Surfaces  277  and  279  are provided in side members  273  to enable the fastener stock to be more easily removed (i.e., peeled off) from the cavities of the mold wheel during the fabrication process.  
         [0082]    Stock  271  is formed a manner analogous to that used to form stock  101 , the notable difference being that the shape of the mold wheel impression and the shapes of the skiving knife cut-outs are different for stocks  101  and stock  271 . That portion of side member  273  that is attributable to the cut-out of the skiving knife used to make stock  271  is designated in FIG. 14 by reference numeral  280 .  
         [0083]    Referring now to FIG. 15, an individual fastener  276  derived from fastener stock  271  is shown with its cross-bar  278  disposed within bore  59  of needle  51 . As can be seen, due to the addition of portion  280 , cross-bar  278  more completely fills bore  59  than it otherwise would have. This reduction in unused space within bore  59  is desirable as it means that cross-bar  278  is more likely to be properly engaged by an ejector rod and moved translationally through bore  59  in a proper manner. Furthermore, the addition of portion  280  will better retain cross-bar  278  within bore  59  since any upward movement of fastener  276  within stem portion  53  of needle  51  (in the direction of arrow A) will case surface  280 - 1  as well as surface  278 - 1  to hit up against sidewall  59 - 1  of bore  59 . However, one disadvantage to the addition of portion  280  to cross-bar  278  is that the fabrication of cross-bar  278  requires more plastic than a cross-bar which is lacking portion  280  (or more than cross-bar  23 ). Such an increase in materials, when extrapolated for a high volume of stock, can result in a considerable increase in manufacturing cost.  
         [0084]    Referring now to FIG. 16, there is shown an end view of a fourth embodiment of a length of continuously connected fastener stock of the plastic staple variety that has been fabricated in accordance with the teachings of the present invention, said length of fastener stock being represented generally by reference numeral  301 .  
         [0085]    Fastener stock  301  is similar to fastener stock  101  in that fastener stock  301  comprises a pair of elongated, uniform and continuous side members  303 - 1  and  303 - 2  that are coupled together by a plurality of flexible cross-links  305  that are equidistantly-spaced apart. Preferably, cross-links  305  are spaced apart by a distance of 0.18 inch. Fastener stock  301  like stock  101  is preferably constructed of urethane.  
         [0086]    An individual plastic fastener  302  that has been cut from fastener stock  301  is shown separately in FIG. 17 and can be seen to include a pair of cross-bars  304 - 1  and  304 - 2  interconnected by a cross-link  305 . As can be appreciated cross-bars  304 - 1  and  304 - 2  have a length of 0.18 inches.  
         [0087]    As seen best in FIG. 16, fastener stock  301  differs from fastener stock  101  in two principal ways. First, side members  303 - 1  and  303 - 2  of fastener stock  301  are circular in transverse cross-section with a diameter of about 0.030 inches whereas side members  103 - 1  and  103 - 2  of fastener stock  101  are elliptical in transverse cross-section. Second, cross-links  305  of fastener stock  301  asymmetrically bisect side members  303 - 1  and  303 - 2  whereas cross-links  105  of fastener stock  101  symmetrically bisect side members  103 - 1  and  103 - 2 . In fact, as can be seen, edge  306  of cross link  305  lies flush with side members  303 - 1  and  303 - 2 .  
         [0088]    One of the advantages of stock  301  over stock  11  and stock  101  is that side members  303  (and the individual cross-bars derived therefrom) have a cross-sectional transverse shape that more closely conforms to the circular transverse shape of bore  59  of needle  51 . Consequently, less wasted space is present in bore  59  and improved engagement of the cross-bar by the ejector rod and improved translational movement of the cross-bar through the length of bore  59  is made possible.  
         [0089]    Another desirable property of stock  301  is that side members  303 , while having a much different shape than conventional side members  13 , have a cross-sectional area that substantially matches that of conventional side members  13 . Consequently, side members  303  do not require an increase in manufacturing materials.  
         [0090]    Fastener stock  301  may be fabricated in a manner similar to that used to make fastener stock  101 . One notable difference is that, instead of using skiving knife  111 , skiving knife  311 , which is shown in FIGS.  18 ( a ) and  18 ( b ), is used. Another difference is that a mold which has an appropriately shaped impression is used, said impression preferably defining cross-links  305  and side members of semi-circular transverse cross-section. As seen best in FIG. 18( b ), skiving knife  311  is similar in many respects to skiving knife  111 , the principal difference between the two knives being that skiving knife  311  is provided with a bottom edge  313  having a pair of generally semi-circular cut-away portions  315 - 1  and  315 - 2 , as compared to the semi-elliptical cut-away portions  115 - 1  and  115 - 2  of knife  111 .  
         [0091]    Referring now to FIG. 19, there is shown an end view of another embodiment of a length of continuously connected fastener stock of the plastic staple variety that has been fabricated in accordance with the teachings of the present invention, said length of fastener stock being represented generally by reference numeral  401 .  
         [0092]    Fastener stock  401  is similar to fastener stock  301  in that fastener stock  401  comprises a pair of elongated, uniform and continuous side members  403 - 1  and  403 - 2  that are coupled together by a plurality of flexible, equidistantly-spaced apart cross-links  405 . Preferably, cross-links  405  are spaced apart by a distance of 0.18 inches. Fastener stock  401  is preferably constructed of urethane.  
         [0093]    An individual plastic staple  402  that has been cut from fastener stock  401  is shown separately in FIG. 20 and can be seen to include a pair of cross-bars  404 - 1  and  404 - 2  interconnected by a cross-link  405 .  
         [0094]    Fastener stock  401  differs from fastener stock  301  in two principal ways. First, side members  403 - 1  and  403 - 2  of fastener stock  401  are generally circular in transverse cross-section but are shaped to include a pair of flat surfaces  407  and  409  whereas side members  303 - 1  and  303 - 2  of fastener stock  101  are completely circular in transverse cross-section. Second, cross-links  405  of fastener stock  401  asymmetrically bisect side members  403 - 1  and  403 - 2  at a different location than where cross-links  305  of fastener stock  301  asymmetrically bisect side members  303 - 1  and  303 - 2 . More specifically, cross-links  405  do not lie flush with side members  403 - 1  and  403 - 2 .  
         [0095]    With respect to the first difference, as seen best in FIG. 21 side member  403 - 2  includes an outer flattened surface  407  and an inner flattened surface  409 , flattened surfaces  407  and  409  being oppositely sloped. The purpose of flattened surfaces  407  is to enable the fastener stock to be more easily removed (i.e. peeled off) from the cavities of the mold wheel during the fabrication process. Preferably, the diameter D 1  of each side member  403  is 0.032 inch and the shortest distance D 2  between outer flattened surface  407  and inner flattened surface  409  is 0.030 inch.  
         [0096]    With respect to the second difference, cross-links  405  of fastener stock  401  asymmetrically bisect each side member  403  at a location closer to the center of side member  403  than where cross-links  305  of fastener stock  301  asymmetrically bisect side members  303 . As a result, a rounded notch  411  extends laterally at the junction between cross-links  405  and each side member  403 . As can be appreciated, the laterally extending shape of side members  403  on both sides of cross links  405  helps to prevent side member  403  from being inadvertently withdrawn from bore  59  of needle  51 , which is highly desirable. Also, because cross-link  405  is more centrally located relative to side member  403  than is the case with cross-link  305  and side member  303 , cross-link  405  need not be bent as severely to pass through slot  61  of needle  51  as is the case with cross-link  305 .  
         [0097]    It should be noted that a principal advantage of stock  401  over stock  11  is that side members  403  (and the individual cross-bars derived therefrom) have a cross-sectional transverse shape that more closely conforms to the circular transverse shape of bore  59  of needle  51 . In fact, providing side members  403  with the aforementioned shape leads to two significant benefits.  
         [0098]    As a first benefit, by reducing the amount of unused space within bore  59 , side members  403  permit improved engagement with an ejector rod, thereby resulting in better translational movement of the cross-bar through the length of bore  59 .  
         [0099]    As a second benefit, by shaping side members  403  to correspond to the overall shape of bore  59  of needle  51  while keeping the cross-sectional area of side members  403  the same as that for side members  13 , one can then design a needle having a smaller diameter, thereby leading to a smaller insertion hole.  
         [0100]    Referring now to FIG. 22, there is shown a transverse section view of the stem portion of a reduced sized needle constructed according to the teachings of the present invention, the needle being identified by reference numeral  413 . Needle  413  differs from conventional needles, such as needle  51 , in that needle  413  is shaped to define a bore  415  which is considerably smaller in diameter than the bore of conventional needles used in fastener dispensing applications. Specifically, needle  413  and is shaped to define a bore  415  having an inside diameter of about 0.032 inches, wherein, as noted above, the bore in a conventional needle is about 0.037 to 0.040 inches. It should be noted that the considerable reduction in the diameter of the bore is achievable without compromising the strength of the needle, which is highly desirable.  
         [0101]    A section view showing an individual plastic staple  402  within bore  415  of needle  413  is shown in FIG. 23.  
         [0102]    As can be seen by having a cross-bar  404  that is circular in cross-section rather than a cross-bar having a flat side  25 - 1  and an arcuate side  25 - 4  as shown in FIG. 2, cross-bar  404  will better be retained within bore  415  since any upward movement of cross-bar  404  will cause a greater portion of surface  404 - 1  to hit up against the inner wall  413 - 1  of needle  413  than would occur if the cross-bar were shaped as shown in FIG. 2.  
         [0103]    The embodiments of the present invention recited herein are intended to be merely exemplary and those skilled in the art will be able to make numerous variations and modifications to it without departing from the spirit of the present invention. All such variations and modifications are intended to be within the scope of the present invention as defined by the claims appended hereto.