CROSS-REFERENCE TO RELATED APPLICATIONS
FIELD OF THE INVENTION
This application claims priority in U.S. provisional application serial No. 60/389,358, filed on Jun. 15, 2002.
- BACKGROUND OF THE INVENTION
The present invention relates to magnetic clasps and, more particularly, relates to a concealed secure magnetic clasp for jewelry.
Jewelry is generally very costly. Many types of jewelry, such as bracelets and necklaces, include fastening devices and/or closures that affix one end of an open loop to another to close the loop. The security and reliability of such fastening devices and/or closures are important factors in the value of the jewelry. Nearly all solutions in the jewelry industry involve solid mechanical clasps, clips, loops, snaps, buckles, threaded assemblies, and the like. For a variety of reasons, only a very few effect fastening and closure through the use of magnetic attraction.
Known magnetic clasp assemblies in the jewelry industry involve a variety of self-aligning, butted, conical, round, square, rectangular, and tubular designs. Some are mechanically simple configurations while others are mechanically complex configurations. Magnetic clasp assemblies are also used in applications other than jewelry, but the jewelry industry and its market places special importance upon attributes such as appearance that are not necessarily significant in those other fields. All prior art configurations, whether jewelry-related or not, involve considerable compromises.
One problem with existing magnetic jewelry clasps is their appearance. The appearance of the magnetic fixture may detract from the appearance of the item of jewelry. The appearance of a magnetic clasp, in turn, may give rise to security concerns. An observer may see that two ends of a strap, rope, belt, or strand are held together only by a magnetic fixture, and may correctly assume that they are separable with no more than a simple tug. To alleviate this concern, additional mechanical affixing devices such as loops, snaps, and clips are often employed, which virtually eliminate the fundamental advantage of the magnetic closure.
Another problem with magnetic clasps, especially those in which magnetic surfaces are butted together in the simplest way, is that attraction (and therefore security) is greatest by far when the two surfaces are perfectly parallel and in uniform contact across their respective common planar surfaces. Any partial dislodgment or relative tipping of the two components that damages the perfection of that 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, the ability of the secured components to move relative to each other increases the probability of complete separation and loss of the jewelry.
Another problem with existing magnetic jewelry clasps is their size and bulk. Because the mass required to maintain adequate security of the fastening system is rarely consistent with the aesthetic intent of the designer, compensatory design features and compromises are usually required. These and other attempts to overcome deficiencies in the concept have led to increased manufacturing costs. Execution in general has grown from simple to very complex, with a commensurate increase in manufacturing costs.
- SUMMARY OF THE INVENTION
While many of the prior art magnetic clasps may be suitable for the particular purposes for which they are intended, they are not optimum solutions for jewelry and other applications, and generally involve a variety of compromises in aesthetics, functionality, ease of use, security, and cost of manufacture. The concealed secure magnetic clasp of the present invention substantially departs from and has substantial advantages over the conventional concepts and designs of the prior art.
In view of the foregoing disadvantages inherent in known methods and mechanisms for magnetically connecting elements of jewelry and other items, the present invention provides a new and superior method and mechanism that is aesthetically pleasing, secure, easy to use, and inexpensive to manufacture.
One object of the invention is to enable two ends of a rope, loop, band, belt or other item to be affixed one to the other using a magnetic closure in a unique manner that avoids the problems of prior art.
Another object of the invention is to provide a magnetic closure with an outer housing having dimensions that force the alignment of the magnetic faces of the two ends, thereby maximizing parallelism and the magnetic bond, and minimizing security risk.
Another object of the invention is to provide a magnetic closure for jewelry having a decorative outer housing that is a major aesthetic feature of the jewelry, thus rendering the magnetic nature of the closure less obvious.
Another object of the present invention is to provide a magnetic closure that is economical to manufacture using simplified and low-cost components and assembly techniques.
Another object of the invention is to provide a magnetic closure for jewelry that is easy to use, minimizing the need for manual dexterity while maximizing security.
Another object of the invention is to provide a magnetic closure that optionally integrates an intrinsic mechanical lock, achieved without additional moving parts and by using the magnetic attraction of the clasp components to effect a mechanical lock. The optional mechanical lock is simple and easy to use and provides security beyond that of the magnetic clasp itself.
Another object of the invention is to provide a magnetic closure for jewelry that is optionally configured to minimize the magnetic field of the assembly, thus reducing the likelihood of attracting ferrous detritus in the environment.
Another object of the invention is to exploit health advantages of magnetic devices, insofar as any exist, by adding magnetic materials to a jewelry item, and thus generating magnetic fields.
Accordingly, one embodiment of the invention is a jewelry clasp including a magnetic clasp assembly. A first magnetic component has a first mating face and is affixed to a first free end of a band, and a second magnetic component has a second mating face and is affixed to a second free end of the band. A housing is affixed to the second free end of the band and defines a recess for insertion of the first free end. The housing conceals the first and second magnetic components when the magnetic clasp. assembly is engaged, and is configured with internal dimensions that force optimal alignment of the first and second mating faces. In one implementation, the clasp further includes a mechanical lock that is engaged and maintained with the help of the magnetic attraction provided by the magnetic clasp assembly.
Another embodiment of the invention is a clasp for an item of jewelry. A housing is attached to a first free end of a jewelry band and defines a receptacle for receiving a second free end of the jewelry band. A detent is formed within the receptacle, and a first magnetic component is embedded in and flush with an interior surface of the receptacle. A second magnetic component is attached to the second free end of the jewelry band and is configured to engage and mate with the first magnetic component in a parallel and uniform area of contact to establish a magnetic lock. A hook is attached to the second free end of the jewelry band and is configured to fit within the detent to establish a mechanical lock.
BRIEF DESCRIPTION OF THE DRAWINGS
Other embodiments, features, objects and advantages of the invention will be apparent to one of skill in the art upon examination of the following figures and detailed description. It is intended that all such additional embodiments, features, objects and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.
The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the figures, like reference numerals designate corresponding parts throughout the different views.
FIG. 1 is a perspective view of an item of jewelry including a magnetic clasp according to the present invention.
FIG. 2 is a side elevation view of the item of jewelry of FIG. 1.
FIG. 3 is a partial, enlarged top view of the item of jewelry of FIG. 1 showing operation of the inventive magnetic clasp.
FIGS. 4a-4 c illustrate incremental stages of coupling a second embodiment of a magnetic clasp according to the present invention.
FIGS. 5a-5 c illustrate incremental stages of coupling a third embodiment of a magnetic clasp according to the present invention.
FIG. 5d illustrates a fourth embodiment of a magnetic clasp according to the present invention.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.