Abstract:
Magnetic clasps for securing the opposed ends of chains and other jewelry. Each clasp includes an arrangement for securing separable bodies by means of magnets that have been poled to present opposed surfaces of opposite magnetic polarities. In a first embodiment, disk-like magnets are received in channels of mating elongated body members of like configuration. End flanges of the elongated body members, in addition to the disk-like magnets, provide axial resistance to separation while the resultant magnetic force prevents separation in the transverse direction. In a second embodiment, disk-like magnets of divided polarities are seated at ends of mating bodies. A pin-and-slot locking mechanism is formed in the two bodies and the magnets are oriented relative thereto so that resultant repulsive magnetic forces force the two magnets into mating alignment when in the longitudinal slot for maximum magnetic holding force. In a third embodiment, magnetic disks are held side-by-side by holders within a split hemispherical housing.

Description:
REFERENCE TO RELATED APPLICATION  
       [0001]    The present application is a continuation-in-part of pending U.S. patent application Ser. No. 09/487,424 of co-inventors George Gero, Leslie C. Hoffman and Raymond D. Lathrop covering “Cuff Link With Changeable Element” filed Jan. 20, 2000. 
     
    
     
       BACKGROUND  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to articles that facilitate the use of jewelry. More particularly, this invention pertains to jewelry clasps in which clasp members are secured, at least in part, by magnetic force.  
           [0004]    2. Description of the Prior Art  
           [0005]    The design of articles of jewelry is complicated by the need to combine function with appearance. Often a tradeoff is involved and such tradeoff is made particularly difficult when a device, such as a clasp is responsible for the security of often-extremely valuable articles such as pearls, pendants, necklaces and the like.  
           [0006]    Clasps come in numerous designs and employ many functional means for securing to the wearer. While providing a secure locking mechanism, the design of a truly effective clasp must accommodate ready and mostly blind manipulation by the wearer. The size and shape of the clasp must not detract from less-functional elements of the jewelry.  
           [0007]    As a consequence of the above criteria, it is recognized that the design of an easy-to-manipulate and secure clasp that does not detract from, and, in fact may add to the appearance and value of a necklace or the like poses a significant challenge to the jewelry designer/manufacturer.  
         SUMMARY OF THE INVENTION  
         [0008]    The preceding and other shortcomings of the prior art are addressed and overcome by the present invention that provides, in a first aspect, a clasp for selectively joining a first element to a second element. Such clasp includes a first body member having a flange adapted to receive the first element. A second body member has a flange adapted to receive the second element.  
           [0009]    Each of the body members includes at least one magnet. The body members are arranged so that a common magnetic field selectively secures the members to one another.  
           [0010]    In second aspect, the invention provides a clasp for selectively joining a first element to a second element. Such clasp includes an elongated first generally-cylindrical body of a first diameter having opposed open and closed ends. A flange is fixed to the exterior surface of the closed end of the elongated first body.  
           [0011]    A first disk-like magnet is arranged transverse to the axis of symmetry of and within the elongated first generally-cylindrical body. Such first disk-like magnet comprises semicircular disk regions divided by a first diameter with each semicircular disk region having opposed major surfaces of opposite magnetic polarity. Semicircular disk regions of the first disk-like magnet have major surface regions of opposite polarities on opposite sides of the first diameter.  
           [0012]    An elongated second generally cylindrical body of a second diameter has a first closed end. A flange has an internal aperture fixed to the closed while the opposed end is closed by a second disk-like magnet arranged transverse to its axis of symmetry. The second magnet comprises two semicircular disk regions divided by a second diameter, each with opposed major surfaces of opposite magnetic polarity. The major disk regions of the second magnet are of opposite magnetic polarities at opposed sides of the second diameter. The second diameter is less than the first diameter whereby the elongated second generally cylindrical body may be received within the elongated first generally-cylindrical body.  
           [0013]    In a third aspect, the invention provides a clasp for selectively joining a first element to a second element that includes a first generally-hemispherical housing element and a second generally-hemispherical housing element. A first magnet and a second magnet are provided. A first holder is adapted to receive the first magnet within the first generally-hemispherical housing and a second holder is adapted to receive the second magnet within the second generally-hemispherical housing.  
           [0014]    Each of the first and second magnets comprises opposed surfaces of opposite magnetic polarity and the first and second holders are arranged to position the first magnet relative to said second magnet when the first and second generally-hemispherical housing elements are oriented to form a hemisphere so that surfaces of opposite magnetic polarity of the first and second magnets are adjacent one another.  
           [0015]    The preceding and other features and advantages of the present invention will become further apparent from the detailed description that follows. Such description is accompanied by a set of drawing figures. Numerals of the drawing figures, corresponding to those of the written description, point to the features of the invention with like features referring to like features throughout both the written description and the drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is a perspective view of a clasp in accordance with a first embodiment of the invention;  
         [0017]    FIGS.  2  ( a ) and  2  ( b ) are side elevation and top planar views of the component elements of the clasp of FIG. 1, such elements being juxtaposed to facilitate one&#39;s appreciation of the manner of assembly and latching of the device;  
         [0018]    [0018]FIG. 3 is a cross-sectional view of the closed clasp of the invention taken at line  3 - 3  of FIG. 1;  
         [0019]    [0019]FIG. 4 is an exploded perspective view of a magnetic clasp in accordance with an alternative embodiment of the invention; and  
         [0020]    FIGS.  5  ( a ) and  5  ( b ) are assembled and exploded perspective views, respectively, of a magnetic clasp in accordance with a second alternative embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0021]    [0021]FIG. 1 is a perspective view of a clasp  10  in accordance with the invention. The clasp  10  may provide a means for selectively connecting the opposed ends  12 ,  14  of a jewelry chain. The clasp  10  provides a secure and easily manipulated means that resists axial separation of mating body members  16 ,  18  with a design that offers mechanical resistance to axial force as the members  16 ,  18  are held together by magnetic force. Such magnetic force, in turn, permits simpler attachment and detachment of the members  16 ,  18  than prior art clasps that rely upon mechanical affixation arrangements. It will be further seen that the design of the clasp  10  assures that the separable body members  16 ,  18  cannot be accidentally joined in such a way that the advantages of the invention are not realized.  
         [0022]    FIGS.  2  ( a ) and  2  ( b ) are side elevation and top planar views of the component elements of the clasp  10 , such elements being juxtaposed to facilitate an appreciation of the manner of latching of the clasp  10 . Each of the mating body members  16 ,  18  includes a frame  17 ,  19 , respectively, of nonmagnetic material having an interior slot  20 ,  22  respectively for receiving cylindrical magnets  24  and  26 . The magnets  24 ,  26  are fixed therein adjacent distal end members  25  and  27  of the frames  17  and  19  respectively. Each of the distal end members  25  and  27  is integral with the associated frame and, of course, of identical nonmagnetic material. As can be seen in FIG. 3, a cross-sectional view of the clasp taken at line  3 - 3  of FIG. 1, the interior slots  20  and  22  in combination form a cylindrical cavity for receiving the magnets  24 ,  26  when the clasp  10  is closed.  
         [0023]    The magnets are each poled to have opposed circular surfaces of opposite magnetic polarities. The are, in turn, aligned within the slots  20  and  22  so that facing surfaces of the two magnets  24  and  26  are of opposite magnetic polarity. In this way continuous paths of magnetic flux through the (magnetic or nonmagnetic) metallic bodies of the mating members  16  and  18  and the magnets  24 ,  26  are achieved and a strong magnetic bond formed. This bond is readily broken when desired by simply twisting the two members  16  and  18  from one another with one&#39;s fingertips. Unlike prior art clasps, difficult manipulations of small mechanisms is not required. In addition, by providing non-magnetic distal end members  25 ,  27  to thereby “shield” the ends of the frames  17  and  19  so that magnetic flux is not emergent therefrom, unintended end-to-end mating of the body members  16  and  18  cannot occur. This is particularly significant as such an end-to-end arrangement, a potential hazard of often-blind assembly, would not enjoy the benefit of mechanical resistance to axial separation forces (discussed below).  
         [0024]    Each of the slots  20 ,  22  is closed by a disk-like proximal end member formed integral with the body members  16  and  18  respectively. The proximal end members  28 ,  30  are arranged transverse to the longitudinal axes of the slots  20 ,  22  and provide a location for fixing flanges  32 ,  34  having apertures  36  and  38  respectively that provide means for joining the opposed ends  12 ,  14  of a chain to the clasp  10 . The side-by-side relationship between the cylindrical magnets  24 ,  26  within the cylindrical cavity, combined with the fact that each of the magnets  24  and  26  is positioned remote from the associated proximal end member  28  or  30  (to which outwardly-axial force may be applied from the ends  12 ,  14  of the chain) creates a mechanism for mechanically preventing axial forces (due, for example to the weight of a pendant or the force of a tug on an attached chain) from dislodging the magnetically-bonded mating body members  16 ,  18  from one another.  
         [0025]    [0025]FIG. 4 is an exploded perspective view of a magnetic clasp  40  in accordance with an alternative embodiment of the invention. In this embodiment, magnetic forces are employed to facilitate the interlocking of elongated first and second generally cylindrical bodies  42  and  44  respectively. End members  46  and  48  are attached to the open-ended bodies  42 ,  44  and include apertures  50 ,  52  for receiving the ends of a chain (not shown) in use. Disk-like magnets  54 ,  56  are fixed to the first and second bodies respectively. Each of the magnets is poled so that one half of a major surface (divided by a diameter) is of one magnetic polarity and the other half is of opposite polarity. The opposed surface of each magnet  54 ,  56  is poled to be of reversed polarities so that, in effect, each of the two magnets  54 ,  56  is comprised of two side-by-side semicircular disks of reversed polarizations.  
         [0026]    The magnet  54  that is fixed to the end of the body  42  is divided into regions of opposite magnetic polarities along a diameter  58  whereas the magnet  56  that caps the open end of the second body is similarly divided at a diameter  60 . The inner diameter of the elongated first generally-cylindrical body  42  is somewhat larger than the outer diameter of the elongated second generally-cylindrical body  44 . This permits the insertion of the elongated second generally-cylindrical body  44  into the elongated first generally-cylindrical body for close the clasp  40 .  
         [0027]    A keying arrangement further secures the relationship between the elongated first and second generally-cylindrical bodies  42  and  44 . This relationship is accomplished by the interaction of L-shaped slots formed interior to the first elongated generally-cylindrical body  42  with radially-directed pins of the elongated second generally-cylindrical body  44 . A first L-shaped slot  62  includes a longitudinal slot portion  64  that terminates at and intersects a radial slot portion  66 . A like L-shaped slot  68  is formed 180 degrees from the slot  62 .  
         [0028]    Radially-directed pins  70  (only one visible in the figure) emerge from the second body  44  to interact with the slots  62  and  68  and thereby lock the bodies  42  and  44  to one another. The distance “d” that separates the radial slot portion  64  from the interior surface  72  of the magnet  54  is equal to the distance between the pin  70  and the surface  74  of the magnet  56  that faces the elongated first generally-cylindrical body  42 . This assures that the surfaces  72  and  74  are closely adjacent one another when the elongated generally-cylindrical bodies  42  and  44  are locked to one another. Additionally, the two magnets  54  and  56  are so arranged with respect to one another that the diameters  58  and  60  that delineate the borders between areas of unlike magnetic polarizations of the two magnets are angularly displaced by 90 degrees from one another when the pin  70  is in the longitudinal slot portion  64 . This occurs as the elongated first and second generally-cylindrical bodies  42  and  44  are either in the process of being joined into locked engagement or being separated from one another.  
         [0029]    By angularly offsetting the regions of like magnetic polarization from one another while the pin  70  is in the longitudinal slot  64  and in the process of being advanced into engagement, one can be assured that there will exist both attractive and repulsive forces (or increasing magnitudes) between the magnets  54  and  56  as the elongated first and second generally-cylindrical bodies  42  and  44  are advanced into engagement. The magnets  54  and  56  are further arranged so that, as the pin  70  is advanced through and to the terminus of the radial slot portion  66 , the diameters  58  and  60  come into alignment with regions of the adjacent magnet surfaces  72  and  74  of opposite polarities lying atop one another. This assures that the mechanical interlock provided by the interaction of slot and pin is enhanced by the magnetic attraction between the magnets  54  and  56 .  
         [0030]    FIGS.  5  ( a ) and  5  ( b ) are assembled and exploded perspective views, respectively, of a magnetic clasp  76  in accordance with a second alternative embodiment of the invention. The clasp  76 , unlike the prior elongated embodiments, offers a spherical appearance. As in the case of the prior embodiments, it employs magnetic force to secure engagement between its mating halves.  
         [0031]    Viewing FIGS.  5  ( a ) and  5  ( b ) in combination, the clasp  76  includes mating hemispherical housings  78 ,  80 . Flanges  82  and  84  having apertures  86  and  88  extend from the edges of the hemispherical housings  78 ,  80  and provide a means for attachment of the ends of a chain. Hook-like holders  90 ,  92  extend within and are fixed to the hemispherical housings  78  and  80  respectively. The holders are crimped to and thereby secure disk-like magnets  94 ,  96 . Each of such magnets  94  and  96  is poled so that opposed surfaces are of opposite magnetic polarities. The holders  90  and  92  are fixed to the associated hemispherical housings to be offset from and adjacent one another. In this way, the disk-like magnets  94 ,  96  held therein are positioned adjacent one another when the clasp  76  is closed to form a sphere. The magnets are arranged so that surfaces of opposite magnetic polarities thereof are adjacent one another when the clasp  76  is closed. This may be seen to resemble the manner in which the cylindrical magnets  24  and  26  of the clasp  10  are positioned. As in the case of such prior embodiment, the flanges  82  and  84  to which the ends of a chain are attachable, and through which an axial separation force may be applied are so located with respect to the holders  90 ,  92  and magnets  94 ,  96  that, upon encountering an axial tension force, the disk-like magnets  94  and  96  abut against one another to provide resistance to axial separation as in the case of the clasp  10 . The combination of mechanical resistance to undesired axial separation with simple-to-manipulate magnetic closure and opening characterizes this embodiment as is the case of the embodiment of FIGS. 1 through 3.  
         [0032]    Thus it is seen that the present invention provides magnetized clasps that are particularly suitable for jewelry. By utilizing the teachings of this invention one may obtain the advantages of mechanical resistance to separation coupled with the easy-to-manipulate closure and opening offered by the substitution of a magnetic for a mechanical closure arrangement.  
         [0033]    While the present invention has been described with reference to its presently-preferred embodiment, it is not limited thereto. Rather, this invention is limited only insofar as it is defined with respect to the following set of patent claims and includes within its scope all equivalents thereof.