Abstract:
A substantially rigid shaft is obtusely angled adjacent to an enlargement at its distal end. The proximal end of the shaft and a receptacle, forming and defining an aperture slightly smaller than the enlargement, are flexibly affixed to differing portions of an encircling article that become releasably joined when the enlargement is forcibly passed through the aperture, Highly resistive to accidental opening, purposeful pressure applied to the enlargement by a single finger or thumb creates a leveraged force that assists the pressure in accomplishing intentional disengagement. Optional attributes include a magnetic pre-positioning for engagement and disengagement and use of gemstones as distal enlargements.

Description:
NOTICE 
       [0001]    A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 
       CROSS REFERENCE TO RELATED APPLICATIONS 
       [0002]    Not applicable 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0003]    Not applicable 
       REFERENCE TO A “MICROFICHE APPENDIX.” 
       [0004]    Not applicable 
       BACKGROUND OF THE INVENTION 
       [0005]    1. Field of the Invention 
         [0006]    This invention relates to releasable fasteners, particularly to snap fasteners which consist of an insert part that must be forcibly inserted into a receptacle part, typically having an aperture slightly smaller than the insert part. These two parts are attached to respective portions of an article which will be joined or united by the fastener when a completed insertion closes the fastener. The fastener is also made so that the insert part must be forcibly removed from the receptacle to release and separate them, in order to provide a resistance to premature disengagement. 
         [0007]    2. Background Information 
         [0008]    Snap-fasteners have been successfully accepted for a wide variety of usages and without major modification for a considerable period of time. Snap fasteners generally offer the inherent convenience of eliminating a need for use of the fingernails in opening, and requiring only one hand for closure. However, two hands must often be used to open them unless the fasteners are so easily disengaged that a secure closure is compromised. 
         [0009]    Despite the successes, many have felt the need to improve the appearance and the already impressive level of snap fastener convenience as well as to make the fasteners more secure against premature disengagement. Such improvements in the matter of appearance and security have been accomplished without compromising convenience. See applicant&#39;s “Jewelry Clasp” U.S. Pat. No. 5,642,558 (Jul. 7, 1997). 
         [0010]    Another example is “Connector for a Jewelry Flexible Member”, Jacobson, U.S. Pat. No. 6,634,067 B2, (Oct. 21, 2003) which shows insert parts which are ball shaped, cylindrical and disc shaped together with receptacles which are hemispherical, semi-cylindrical and disc shaped. “The preferred embodiments of the invention all have a connector with only two parts, namely a receiver and an insert, which are connected to opposite ends of a flexible member.” (Column 2, lines 13-16). 
         [0011]    “To disconnect the parts, since tension on the flexible member ends cannot pull the insert through the opening, the insert must be pulled outward by hand in a direction perpendicular to the orientation of connected flexible members under tension.” (Column 2, lines 33-37”. The invention outlines this method of disengagement for all embodiments, but it is also claimed that the disc shaped connector 90 in FIG. 3 can be disconnected with one hand. “To disconnect connector 90, receiver 94 is first reoriented such that opening 105 faces inward, then receiver 94 is pulled away from insert 92 against the restraint of flexible member end 96”. (Column 6, lines 31-34). 
         [0012]    In addition to other obvious differences, the members “under tension that connect the connector” are flexible, as described and claimed by Jacobson, precluding development of a leveraged force of disengagement, which is an important feature of applicant&#39;s invention which requires a substantially rigid shaft connection for the insert part. In addition to being flexible, Jacobson connecting members are not angled, obtusely or otherwise. 
         [0013]    The first two of three earlier patents are both entitled “Fastening for Gloves”, Richardson, U.S. Pat. No. 276,714 (May 1, 1883) and U.S. Pat. No. 300,509 (Jun. 17, 1884) The first patent is primarily concerned with manufacture of the Richardson fastener, the second with its operation. Both show a ball member and a socket that is adapted to be shut over the ball to enclose the upper and side surfaces of the ball member in order to secure it. There is a mention of a curved shank (shaft) in the second patent but this is shown in claim 6 to be a reference to its cross-section. There are no angled shanks (shafts) shown or described. There is a mention of a lever action in removing the ball from the socket in U.S. Pat. No. 300,509 (Column 2 lines 61 through 71). However this involves the use of a special projection from the ball which has been provided specifically for use as a fulcrum and the fastener does not create a leveraged force of disengagement without the addition of this special projection. 
         [0014]    The third patent is “Snap for Jewelry”, Ford, U.S. Pat. No. 1,406,179 (Feb. 14, 1922) showing an insert stud rising from a flat, circular panel that extends slightly beyond the stud circumference. This is the insert side of the fastener which is snapped into a circular opening in a slotted panel that is the receptacle. The insert piece is directly connected to the article to be fastened by the snap, without a shaft, such as used in the applicant&#39;s fastener. The Ford snap is “an improved snap for jewelry such as is used on bracelets and other strands, but is particularly adapted for use on necklaces” (Column 1, lines 10-12). The drawing shows the fastener insert part directly connected to a flexible chain. 
         [0015]    Ford makes no provision for one-hand, or one finger operation. “When the parts are to be separated, one part is held in one hand and the other in the other hand” (Column 2 lines 69-71). The paragraph in column 2, lines 69-85 describes the process for separation of the parts of the snap which includes a leveraged disconnection of the two pieces. However, generation of leveraged force calls for manually twisting the parts out of alignment and tilting them to separate the snap parts, not simply using a single finger, as in the applicant&#39;s fastener. Column 2, lines 90-95 calls for providing the stud with a jewel for ornamentation. Replacing the stud or insert with a jewel as a working part of the snap insert is not called for or suggested as it is in the applicant&#39;s specification. 
         [0016]    It is apparent that there continues to be enough room for improvement to invite invention and to expand practical usages even further by combining a greater ease of operation with an attractively unobtrusive appearance, a high level of security and a reasonable manufacturing cost. 
       BRIEF SUMMARY OF THE INVENTION 
       [0017]    Attributes of applicant&#39;s invention, include an enlargement at the distal end of an obtusely angled, substantially rigid shaft, which is flexibly affixed to one part of a an article to be joined by the fastener to another part of the article. To close or engage the parts of the fastener and thus join or unite the parts of the article, the enlargement is held, between thumb and finger, against the opening or aperture in a receptacle part of the fastener, which is flexibly affixed to the another part of the article. The enlargement and receptacle are then rotated slightly toward the body, while pulling against the part to which the receptacle is affixed. This action provides a particular advantage in snapping the enlargement through the receptacle, to engage the fastener and join the article parts. 
         [0018]    Articles of clothing, both under and outer wear, belts, articles of jewelry, even shoes may be considered body encircling articles, although the body need not be animate as when the fastener is used to secure hold-down straps. In a proper installation of the applicant&#39;s invention, the enlargement is made to pass through the receptacle aperture in the direction of the body to effect closure. In general the applicant&#39;s fastener is made to have a relatively high resistance to passage of the enlargement through the aperture of the receptacle. This and the hooked effect of shaft angle and bead contour makes it especially secure against accidental opening. Although pulling forces from the article are made to have no effect, pressure applied to the enlargement in a closed fastener, by a single finger or a thumb, that pulls the fastener away from the joined parts of the article, will cause the shaft and receptacle to develop a leveraged force that greatly assists this pressure on the enlargement and forces it back through the receptacle opening or aperture to conveniently disengage the fastener. These modes of fastener engagement and disengagement are particularly valuable when direct physical access and visual assistance are both limited, as when a brassiere design calls for closure and adjustment at the wearer&#39;s back and the fastener may need to be manipulated through a layer or two of fabric. The mode of disengagement makes a relatively great resistance to disengagement more manageable. 
         [0019]    The easy to open, one finger feature of the fastener invention makes it practical in miniature sizes and its minimal use of materials not only tends to give it a lean and attractively less obtrusive appearance, but allows it to be economically made from noble as well as base metals, even in larger sizes. Hard precious or semi-precious stones may also be made to serve as both decorative and functioning distal enlargements. Another feature in the applicant&#39;s invention is a magnetic pre-positioning of fastener parts for engagement or disengagement. Such magnetic positioning does not accomplish the fastening as in a typical magnetic snap fastener, but makes the parts self-locating and holds them in a ready position for fastening. When the fastener is opened the magnetic feature can also serve to temporarily secure the ends of a bracelet or necklace to prevent them from dropping to the floor, after disengagement. 
         [0020]    Either the distal shaft enlargement, receptacle or even both could be made of a permanent magnet material, but it has been found that the most convenient and economical construction uses a permanently magnetic material as the distal enlargement and a receptacle made of a material having ferro-magnetic properties. The permanently magnetic, black glass marketed in bead form as “Magnetic Hematite” is both durably hard and strongly magnetic and serves well as the distal enlargement when used in combination with a receptacle made from an iron alloy wire. Magnetic beads are also available in colors as well as black. 
         [0021]    If the receptacle is to be made of a non-magnetic material such as brass, gold or silver, and the magnetic advantage is desired, it can be given magnetic qualities by adding a ferro-magnetic material in the form of a core or partial covering. In the wire-form designs, this can conveniently be accomplished by closely winding a coil of iron around the part that forms the aperture. 
         [0022]    An object of this invention is to provide a releasable fastener that will accomplish the joining or uniting of article parts in a simple yet reliable manner. 
         [0023]    An associated object is to combine simplicity and reliability with ease of operation. 
         [0024]    Another associated object is to provide the simplicity, reliability and ease of operation, in an unobtrusive manner that will not appreciably interrupt the esthetics of design. 
         [0025]    An additional object is to provide a reliable fastener in which ease of operation is accomplished by the fastener&#39;s ability to be closed or engaged with a thumb and finger of one hand and opened or disengaged with one finger or a thumb. 
         [0026]    Another additional object is to provide a reliable fastener in which ease of operation is such that the fastener can be engaged and disengaged while being manipulated through layers of fabric. 
         [0027]    A further object is to provide a releasable fastener with a decreased resistance to engagement and an increased resistance to disengagement which is overcome by assistance from a leveraged force of disengagement. 
         [0028]    A still further object is to provide such a releasable fastener with the convenience of magnetic pre-positioning for engagement and disengagement. 
         [0029]    Still another object is to provide a releasable fastener that has minimal requirement for materials so that manufacturing expense is reduced, especially when noble metals are employed. 
         [0030]    Yet another object is to permit the practical inclusion of stones as functioning parts of a releasable fastener for their inherent wear resistance as well as their ornamentation. 
         [0031]    An associated object is to provide a releasable fastener that permits an easy swiveling action when closed or engaged. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]      FIG. 1  is a pictorial view of a preferred embodiment of the releasable fastener, in accordance with the invention, attached to a bracelet, with its distal enlargement of spheroid bead form, pre-positioned for engagement over the aperture defined by its wire-form receptacle; 
           [0033]      FIG. 2  shows the fastener of  FIG. 1  with the fastener in an engaged position; 
           [0034]      FIG. 3  depicts the same bracelet as in  FIGS. 1 and 2 , but with a modified form of the preferred fastener embodiment that has its receptacle arranged so that its proximal attachment will apply any pulling force in a direction that is substantially parallel to, or in the same plane as the receptacle defined aperture; 
           [0035]      FIG. 4  shows the releasable fastener of  FIG. 3 , after engagement; 
           [0036]      FIG. 5  depicts a group of preferred receptacles, including those shown in  FIGS. 1-4  as well as one shown in  FIG. 6 ; 
           [0037]      FIG. 6  depicts, a pair of smaller fastener shafts and enlargements affixed to a portion of a brassiere strap; 
           [0038]      FIG. 7  shows, the portion of the brassiere strap of  FIG. 6  after engagement with a pair of wire-form receptacles mounted on another portion of the brassiere strap; and 
           [0039]      FIG. 8  depicts a group of preferred angled shafts with their distal enlargements of preferred spheroid shaping. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0040]      FIG. 1  depicts the substantially rigid, angled shaft  5  of the releasable fastener, with its spheroidal distal enlargement  1 , flexibly affixed by jump ring  6  to one end of bracelet  8  with relatively rigid receptacle  2  flexibly affixed to the opposite end of bracelet  8  by jump ring  7  and defining an aperture with slightly smaller dimensions than those of distal enlargement bead  1 . The bead  1  is shown, pre-positioned for engagement, as it nests well within the aperture defined by receptacle  2  since the relatively rigid properties of receptacle  2 , require less expansion for development of a desired resistance to passage of distal enlargement bead  1 . 
         [0041]    Receptacle  2  in  FIG. 1  is made with its connective eye off-set so that any pulling force transmitted to it through connecting jump ring  7  is at an angle to the plane of the aperture defined by receptacle  2 . This has been found to enhance the action of angled shaft  5  in magnetic pre-positioning. 
         [0042]    Curved arrows  3  and  4  in  FIG. 1  show the direction in which the pre-positioned fastener parts  1  and  2 , held between a thumb and finger, are turned down toward the body as they are pulled away from the restraint of the bracelet connection through jump ring  7 , to create a mechanically advantaged, convenient, releasably locking engagement. 
         [0043]      FIG. 2  shows the ends of bracelet  8 , connected through jump rings  6  and  7  to the angled shaft  5  and receptacle  2  respectively, now having the bracelet ends secured by the passage of bead  1 , through the aperture defined by receptacle  2 , which has engaged the fastener. Again, the enlargement bead  1  is able to nest well within the aperture defined by resiliently deformable receptacle  2 . Due to the relative rigidity of receptacle  2 , a desired degree of resistance to the expanding passage of enlargement  1 , that must be overcome to effect disengagement, is achieved with relatively slight expansion. 
         [0044]    Arrow  9  in  FIG. 2  indicates the direction in which pressure can be applied by a finger or thumb to the enlargement bead  1  to effect a convenient disengagement. In the case of the bracelet, as well as other articles not otherwise secured to the body, use of a finger and thumb can leave the user holding an end of the fastener after disengagement, shaft  5  and bead  1  or receptacle  2 , which will keep the article from falling away. 
         [0045]    Once engaged, pulling force applied to the releasable fastener at the flexibly affixed connection  6  of shaft  5  and  7  of receptacle  2 , can cause the obtusely angled part of the shaft  5  adjacent to the enlargement  1  to ride against the edge of the receptacle and bring the enlargement into a pre-positioning for disengagement, as shown, but the angle of shaft  5  keeps pulling force from developing a leveraged urging that will lift enlargement  1  out of receptacle  2 , and the combination of the obtuse angle of shaft  5  and the curve of the preferred spheroid shaping of enlargement  1 , also creates a “hook” effect to keep such pulling force from causing a disengagement. When the fastener is magnetically equipped, the enlargement  1  tends to maintain such a pre-positioning for disengagement without such pulling. 
         [0046]    When an intentional pressure is applied to the distal end of the enlargement that faces the body, in a direction indicated by arrow  9 , that pulls the fastener away from the body, it applies pulling force to receptacle  2  at an increasingly different angle than when pulling force comes from the article through the fastener&#39;s proximal attachments such as  6  and  7 . Intentional pulling, directly applied to enlargement  1  at the distal end of shaft  5 , that moves the fastener away from the body, develops an angularly leveraged force that assists such intentional pulling. The edge of receptacle  2  that contacts shaft  5  acts as a fulcrum for shaft  5  and helps force the enlargement  1  back through the opening or aperture defined by receptacle  2 , to disengage the fastener and thereby permit the united or joined parts of the article to separate. Pulling at other positions, at the points where the fastener parts are flexibly affixed at  6  and  7  or further from the fastener, on the article with parts to be united, applies pulling force to the fastener in directly opposing directions, does not cause the leveraged force to be developed and does not cause such disengagement. 
         [0047]    While the shaft  5 , is described as obtusely angled adjacent to the enlargement, it should be noted that the angle need not be abruptly formed and can be developed in a curve, as shown. 
         [0048]    If the shaft is left straight, and not obtusely angled as shown by shaft  5 , a leveraged force that urges disengagement is developed when pulling force is applied by the article in typically opposing directions and disengagement is thus made to occur prematurely. 
         [0049]      FIG. 3  depicts the same bracelet  8 , but with a preferred modification of the applicant&#39;s invention. The orientation of the fastener in  FIG. 3  is reversed from that of  FIGS. 1 and 2  and the angled shaft  12  is secured directly to the bracelet end without the use of the attachment ring or “jump” ring  7  used in  FIGS. 1 and 2 . This form of direct attachment facilitates engagement by reducing twisting that might point the spheroid enlargement  10  at the distal end of shaft  12  away from the aperture defined by receptacle  11  and require a slight degree of manual realignment, if the distal spheroid bead  10  is not pre-positioned magnetically, for example. 
         [0050]      FIG. 3  shows this modification of the releasable fastener to have its receptacle  11  not off-set so that its proximal attachment to bracelet  8  will transmit any pulling force applied by bracelet  8  in a direction that is either on, or substantially parallel to, the plane of the aperture defined by receptacle  11 . This type of receptacle is particularly useful on chains or necklaces, since it has no polarity and allows entry of the bead  10  from either side when made accessible.  FIG. 3  also shows the fastener as pre-positioned for engagement with distal enlargement bead  10  over the aperture defined by receptacle  11 . As in  FIGS. 1 and 2 , the receptacle  11  material is to be considered relatively rigid, allowing the bead to nest well within the aperture of receptacle  11  prior to a releasably locking engagement. 
         [0051]      FIG. 4  shows the releasable fastener of  FIG. 4  after releasably locking engagement. Again, the spheroid enlargement  10  is able to nest well within the aperture of receptacle  11  after completing a penetration of  11  and with a minimal protrusion beyond the receptacle  11  due to the relative rigidity of the material from which receptacle  11  is made. Such rigidity permits spheroid bead  10  to be only slightly larger than the aperture defined by receptacle  11 . 
         [0052]    In references to the sizes of distal enlargements and receptacle apertures, it should be interpreted, in this specification, to mean effective sizes, as determined by measurement across those “working” surfaces of the enlargement and aperture that come into contact when the enlargement enters and passes through a temporarily deformed aperture. In general, even when the receptacle appears to follow the contour of the enlargement, there are typically only three and sometimes two contact points therebetween. These may change somewhat with wear and will certainly change if receptacle adjustments are made to increase or decrease the resistance to passage of the enlargement through the aperture defined by the receptacle. 
         [0053]      FIG. 5  depicts a group of preferred receptacles, including those shown affixed to bracelet  8  in  FIGS. 1-4  as well as one like those that will be seen in  FIGS. 6 and 7 . 
         [0054]    The receptacle  2 , shown in two views, is the same receptacle  2  of  FIGS. 1 and 2 , shown with jump ring  7  attached in both views. 
         [0055]    The receptacle  11  is the same receptacle  11  of  FIGS. 3 and 4  with its jump ring  6  attached. 
         [0056]    Receptacle  33  is similar to a type of external retaining ring wherein the small holes that are provided for an expansion tool can be used for thread passage for attachment to apparel, for example. 
         [0057]    The receptacle  30  has inner projections, the ends of which define the aperture. This receptacle resembles another external retaining ring of the push-on type and like the retaining ring it resembles, is made with directional bias. This receptacle presents much less resistance to the enlargement passage in one direction and a much higher resistance to passage in the opposite direction. This makes engagement for the user relatively easy and disengagement very difficult, except when assisted by this fastener&#39;s leveraged force of disengagement. This makes the fastener especially resistant to accidental release or disengagement. Receptacle  30  has a larger external diameter relative to the wire-form types, but this is not objectionable when the fastener is small and  30  could be substituted for the wire-form types  16 ,  17 ,  18  and  19  in  FIG. 7 . 
         [0058]    Receptacle  33  and  30  are both designed to be made of semi-rigid, temporarily deformable material and stamped from flat stock. 
         [0059]    The receptacle  31  is a wire-form type shown in  FIG. 7  as  16 ,  17 ,  18  and  19 . 
         [0060]    The receptacle  32  has its aperture created and defined by a briefly coiled spring wire, in a wire-form generally known in the jewelry and fishing tackle trade as a “split-ring”. As shown by receptacle  32 , the coil consists of more than one turn. One end, at the top of the image, is formed into a connective loop with the other, forming a free end at the right side of the image. 
         [0061]      FIG. 6  depicts a pair of spheroid distal enlargements or beads integrated with their angled shafts  14  and  15 , affixed to one side  13  of a brassiere connecting strap. 
         [0062]      FIG. 7  shows the one side  13  of a brassiere connecting strap of  FIG. 6 , after engagement with wire-form receptacle pair  16  and  17  affixed to another side  20  of the brassiere strap in order to secure and adjust the brassiere. Strap sides such as  20  typically carry a series of additional wire-form receptacles, such as  18  and  19 , which can be seen to resemble the “eyes” of hook and eye fastener combinations, commonly employed as brassiere fasteners. These can be replaced to advantage by receptacles like that depicted as  30  in  FIG. 5 . 
         [0063]    The brassiere is an example of a clothing use in which this releasable fastener has the advantage of being capable of being manipulated through one or more layers of fabric. The force and direction of manipulation and the fastener functioning is like that of the fasteners in  FIGS. 1-4  and it will be appreciated that this fastener use can be extended to belts and other clothing articles such as dresses, shirts and jackets. Since the applicant&#39;s fastener can be operated through layers of fabric, it can be readily concealed when it is considered desirable to do so. 
         [0064]      FIG. 8  depicts a group of preferred angled shafts with their distal enlargements of preferred spheroid bead shaping. A shaft  22  and bead  21  of the type shown in  FIGS. 1-4 , which may be made as an integral piece as well as an assembly, is included as well as two views of a type shown in  FIG. 6  as integral shaft and bead  14  and  15  and shown here as assembled shaft  24  and bead  23 . 
         [0065]    A separate shaft  26  is shown together with its distal bead  25 , which may have permanent magnetic properties, in unassembled form to show construction detail. Shaft  26  has a head  27  not unlike that of a pin head, that is used to assure retention of the bead  25 . While unnecessary for retention, cement may also be used to eliminate any unwanted movement of the bead  25  on the shaft  26 . If the head  27  is pre-formed on shaft  26 , the bead  25  must be installed prior to the forming of the angle and connective eye of  26 . If the shaft  26  is pre-shaped as to angle and eye, the head  27  can be formed after installation of bead  25 , by various means such as soldering, micro-welding, or simply pinching the distal terminus of shaft  26  to increase its width. In any case the head  27  should be finished in a manner that leaves little or no protrusion that could interrupt the contour of bead  25  to an extent that could interfere with fastener functioning. 
         [0066]    In the preferred embodiments, the distal enlargements of the elongated, obtusely angled shafts, have been shown as preferably spheroid although variations in this shape can be made to function if their receptacle apertures can be made to accommodate them. 
         [0067]    When the spheroid is made of metal, it may be made integral with the shaft by casting or stamping as a single piece or by welding an assembly. The spheroid enlargement can also be a drilled bead made of a hard and durable material, including metal, stones, permanent magnet material or be formed in situ on the end of the shaft from glass or plastic. Although acceptable in some instances, the availability of suitable plastic materials is limited and they should generally be restricted to use where expected conditions are not abusive. 
         [0068]    While it would be possible to make the receptacle aperture non-expandable and make the enlargement from a resilient, compressible material to achieve a similar snap-fastener function, the wearing of surfaces must be considered in the interest of reliability, especially after extended use or being subjected to abusive conditions. Hard distal enlargements and resiliently deformable metallic receptacles that define expandable apertures offer the most durable combinations. 
         [0069]    A receptacle that is relatively rigid and expands only slightly in passing the enlargement, is more affected by dimensional changes due to wear and requires more dimensional precision in manufacture, but may be more desirable in appearance. If heavily made of ferro-magnetic material, it may provide an inherently greater mass for magnetic purposes. The wire-form types are also easily adjusted if compensation is required for the eventual effects of wear. If resistance to opening and closing, in a wire-form fastener, is appreciably reduced by wear, squeezing the receptacle sides can restore the resistance. 
         [0070]    A receptacle that is relatively flexible and expands greatly in passing the enlargement, is less affected by dimensional changes due to wear and requires less precision in manufacture, but it may be too lightly made to provide enough ferro-magnetic mass for practical use in the magnetically assisted versions of the fastener and be more suitable for the non-magnetic type of fastener. The enlargement is therefore less nested and is held further out of the receptacle aperture in pre-positions. When greater differences between aperture and enlargement size are desired, a sharper, less obtuse shaft angle should be used to avoid having the shaft stick up out of an engaged fastener at an unattractive angle and to avoid being moved in and out of a partial disengagement when intermittently pulled by the article. 
         [0071]    There are several factors to be considered in deciding whether a receptacle construction that functions with a greater or a lesser degree of expansion, is best suited to a particular usage. 
         [0072]    In general, extremes are to be avoided, and most usages will benefit from a receptacle construction that is flexible enough to avoid undue precision in its requirements and a substantial susceptibility to the adverse effects of dimensional change. However, it should provide the attractive unobtrusiveness of a pronounced nesting for engagement and disengagement pre-positioning and provide enough ferro-magnetic mass to create an acceptable level of attraction, if magnetically equipped. 
         [0073]    While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art, without departing from the true spirit of the invention. It is intended therefore, by the appended claims, to cover all such modifications and changes as fall within the true spirit and scope of the invention.