DETAILED DESCRIPTION

[0028] FIGS. 1-3 depict an item of jewelry 10 fitted with a concealed secure magnetic clasp assembly 20 according to the present invention. Jewelry 10 may be a bracelet (illustrated), watchband, medical sensor or any other wearable item. Although a bracelet 10 is illustrated, it should be understood that the particular embodiment shown in FIGS. 1-3 is for illustrative purposes only and that this invention is not so limited.

[0029] Bracelet 10 comprises a band having two free ends that are secured together by magnetic clasp assembly 20 to form a loop around the wearer's wrist. In the illustrated embodiment, the bracelet band comprises a series of stranded, twisted or braided cables 12 bound together by clamps 14. Clamps 14 serve the utilitarian function of arranging and maintaining cables 12 in a band configuration, and may (optionally) serve a decorative function as well. Again, it should be understood that bracelet 10 is depicted for illustrative purposes only and that many other embodiments are possible and within the scope of this invention. The bracelet band could be formed from a continuous flexible material, for example, rather than from stranded cables that are clamped together. Metal, leather, fiber or any other material that achieves the desired functional and visual effects may be used. In particular, the term “band” as used herein should be understood to cover any rope, loop, band, belt or any other item including two free ends that may be attached by a clasp.

[0030] Magnetic components 22 and 24 are affixed to the free ends of bracelet 10. The magnetic components may be swaged, soldered, welded, crimped, or affixed in any other appropriate manner to the free ends of bracelet 10. In the illustrated embodiment, magnetic components 22 and 24 are affixed to the bracelet ends by fittings 26 and 28. As best seen in FIG. 3, a housing or sleeve 30 is affixed to one free end of the bracelet. Housing 30 surrounds the magnetic component 24 of the bracelet end to which it is affixed, and is configured with an opening 32 and recess 34 to permit insertion of the opposite cable end and its magnetic component 22. Housing 30 and magnetic components 22 and 24 define clasp assembly 20, which preferably (and as illustrated in FIGS. 1-3) has a rectangular cross-section.

[0031] The elasticity of bracelet 10 tends to place magnetic component 22 in the proximity of housing 30. When inserted through opening 32 and into recess 34, magnetic components 22 and 24 attract and cling to each other to establish a bond. As best seen in FIGS. 1 and 2, housing 30 completely conceals magnetic components 22 and 24. Hence, components 22 and 24 are not outwardly visible and do not detract from the aesthetic appearance of bracelet 10. Housing 30 may optionally be embellished with design features 36 such as jewels, gems, carving, inlays, artwork or other features such that it is a dominant and desirable visual feature of bracelet 10.

[0032] Magnetic components 22 and 24 and housing 30 are oriented in order to maximize the strength of the bond. Each of components 22 and 24 preferably has a relatively flat mating surface, and when butted together, are preferably oriented such that the two mating surfaces are perfectly parallel and in uniform contact across their respective common planar surfaces. The plane of contact between the mating surfaces of components 22 and 24 is approximately perpendicular to a plane passing through and parallel with the jewelry band. In alternative configurations, a more rounded shape may be used in order to provide greater flexibility.

[0033] Housing 30 is shaped and configured with internal dimensions and tolerances that force optimal alignment of the two magnetic faces. Flat/rectangular dimensions are preferred (as illustrated), but other shapes such as square, round, oval, triangular or any other shape consistent with the objective of achieving good alignment of the mating magnetic surfaces may be used. Any partial dislodgment or relative tipping of the two magnetic components that damages the perfection of their contact, however slightly, greatly reduces the attractive force and increases the likelihood that the components will separate. The total area of contact also determines the security of the connection, and any lateral movement or sliding of one surface with respect to the other, even while maintaining perfection of the common planar surface, reduces attraction and increases the probability of separation. Hence, housing 30 is configured to inhibit lateral sliding and angular changes that would reduce the magnetic effect.

[0034] The strength of the bond is also dependent on the magnetic materials comprising the mating surfaces of components 22 and 24. One mating surface may be magnetically polarized, while the other is a magnet or a magnetically permeable substance. Suitable magnetic materials include neodymium (preferred), cobalt-samarium, ticonal, and any other permanent magnet materials that achieve a satisfactory combination of bond strength and mass. The other components of bracelet 10 (housing, band, etc.) may be made of any functionally and visually appropriate material.

[0035] FIGS. 4a-c illustrate a second embodiment of the invention employing a mechanical lock to supplement the magnet lock. Preferably, the magnetism provided by the magnetic lock is advantageously employed to help engage the mechanical lock. Clasp assembly 40 is configured to connect and secure the free ends 42 and 44 of an item of jewelry such as a bracelet. Although only the clasp assembly itself is depicted in FIGS. 4a-c, it will be understood that clasp assembly 40 is a part of an item of jewelry such as bracelet 10 depicted in FIGS. 1-3 (i.e., clasp assembly 40 would replace clasp assembly 20). Magnetic component 46 is affixed to free end 42, and magnetic component 48 is affixed to free end 44. Housing 50 is also affixed to free end 44, surrounding magnetic component 48 and defining a receptacle 52 for insertion of free end 42.

[0036] Mechanical lock 58 is defined by a groove or detent 54 milled into one side of housing receptacle 52 and configured to mate with a corresponding projection or hook 56 formed on one side of magnetic component 46. Mechanical lock 58 supplements the magnetic lock 47 formed by the attraction of components 46 and 48. As shown in FIGS. 4a-b, housing 50 is configured such that free end 42 must be inserted at an angle in order to allow hook 56 to engage detent 54. A radius 60 is cut into the interior side of housing 50 opposite lock 58 to facilitate this angular insertion. The opening 62 of housing receptacle 52 may also be beveled to further facilitate this angular insertion.

[0037] Once hook 56 is past detent 54, free end 42 is straightened and elastically returns to its straight orientation within housing 50 to permit mating of the flat opposing surfaces of magnetic components 46 and 48 (FIG. 4c). Magnetic components 46 and 48 are preferably oriented such that their mating surfaces are perfectly parallel and in uniform contact across their respective common planar surfaces, and housing 50 is shaped and configured with internal dimensions that force optimal alignment of the two magnetic faces. In particular, housing 50 is configured to inhibit lateral sliding and angular changes that would reduce the magnetic effect.

[0038] The magnetic attraction between components 46 and 48 preferably helps to “pull” free end 42 into a straightened position and hence may help to engage and maintain mechanical lock 58. In order to further strengthen the magnetic bond and to help engage and maintain the mechanical lock, additional mating side magnets 64 and 66 may optionally be embedded in the free end of the band and the interior of sleeve 30. To disengage clasp assembly 40, free end 42 must be distorted such that it exits housing 50 at the same angle as it entered.

[0039] FIGS. 5a-c illustrate a third embodiment of the invention which also employs a mechanical lock to supplement the magnet lock. Clasp assembly 70 includes a sleeve or housing 72 permanently affixed to one end 74 of a bracelet band or belt. A hook detent 76 is milled into the upper surface 77 of the housing cavity 78, and a flat magnet 80 is embedded in upper surface 77 such that it is flush with surface 77. The opposite (free) end 82 of the bracelet band is swaged, soldered or otherwise permanently bonded to a fixture 84. Fixture 84 has a hook 86 formed at its end that is configured to engage in hook detent 76, as well as a flat magnet 88 embedded in its upper surface that is configured to mate with magnet 80 embedded in sleeve 72.

[0040] When free end 82 is inserted into sleeve 72 (FIG. 5b), magnets 86 and 88 mutually attract, moving fixture 84 laterally, pulling hook 86 into detent 76 and providing a secure mechanical and magnetic lock (FIG. 5c). The plane of engagement between magnets 86 and 88 is not perpendicular to a plane passing through the plane of the jewelry belt, but rather, is at a slight angle to and closer to being parallel with the plane of the jewelry belt. Magnets 86 and 88 are preferably oriented such that their mating surfaces are perfectly parallel and in uniform contact across their respective common planar surfaces, and housing 72 is shaped and configured with internal dimensions that force optimal alignment of the two magnetic faces. In particular, housing 72 is configured to inhibit lateral sliding and angular changes that would reduce the magnetic effect.

[0041] To release the lock requires that free end 82 be slightly lifted at a point prior to sleeve 72, levering end fixture 84 into the position shown in FIG. 5b and permitting withdrawal. A slightly modified embodiment is illustrated in FIG. 5d, in which the sleeve is configured with a thickness to house a functional or ornamental device 90 such as a watch movement. Any thickness is within the scope of the invention, so long as sufficient space is permitted for the latch assembly.

[0042] While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of this invention.