Locking magnetic fastener

A locking magnetic fastener includes manually separable male and female assemblies, the female assembly having an interior chamber accessible through an aperture and containing a magnet, and the male assembly having a projecting member containing ferromagnetic material that is inserted through the aperture into the chamber to be held by the magnet. To assist in holding the assemblies together, the female assembly includes a slide lock member over the aperture that can be slid to one side to admit the projecting member, but which returns to hold the projecting member in place until released by a manual lock release.

FIELD OF THE INVENTION
 This invention relates to a magnetically actuated locking system for
 securely locking together the male and female elements of a fastener until
 released by manual movement of a release. The mechanism has particular
 utility for handbags and cases, and can be used for mechanically securing
 two opposing surfaces that can be brought into aligned superposed position
 while allowing access to the sliding lock release mechanism.
 BACKGROUND OF THE INVENTION
 The use of magnetic fasteners is well known for various end uses and in
 recent years has become very popular in items such as women's handbags.
 However, the most popular magnetic fasteners include providing a firm
 engagement between the elements on the opposed surfaces which are intended
 to be closed and do not provide a locking mechanism. Thus, U.S. Pat. No.
 5,953,795, as an example, describes a non-locking magnetic fastener in
 which the female assembly includes a torroidal magnetic member in which is
 received a ferromagnetic male member.
 In recognition of the need to have a positive locking mechanism, prior
 workers have suggested a number of approaches, but to date, none have been
 widely accepted.
 The present fastener is a significant improvement on the locking magnetic
 fasteners described in the prior art in which the locking mechanism relies
 upon magnetic attraction between a projecting male member and a receiving
 female member. Numerous variations of the prior art devices operating on
 this old principle have been described in the patent literature. For
 example, U.S. Pat. No. 5,572,772 discloses a magnetic fastener consisting
 of a shaped male member that includes a magnet. When the male member is
 inserted into the female assembly, it attracts a ferromagnetic engagement
 member that slides into a position that engages a portion of the male
 member and retains it in a locked position. The male member is released by
 manually displacing the engagement member from the locked position where
 it was held by the magnetic attractive force of the magnet. Another
 construction of a magnetic assembly which uses a slide lock engagement is
 disclosed in U.S. Pat. No. 5,868,445, in which the male assembly includes
 a protruding member or housing with a permanent magnet positioned inside,
 with an opening in the housing through which the magnet is exposed. The
 female assembly includes one or more ferromagnetic plates that slide into
 contact with the male member under the force of the magnetic attraction.
 In U.S. Pat. No. 5,937,487 a locking magnetic fastener having a first and
 second locking position is disclosed, in which the projecting male is
 member includes a magnet that attracts sliding members in the female
 assembly into contact under a recessed portion of the male member.
 It is also known in the art of locking fasteners to provide assemblies and
 constructions in which the internal members are urged into locking
 engagement by a biasing force, such as a spring or other biasing member.
 However, such mechanisms generally require the assembly of a number of
 small parts that must be properly oriented, and therefore are more
 time-consuming and expensive to manufacture, can be less reliable and are
 subject to failure than a simpler construction.
 As noted, non-locking magnetic fasteners are well known and generally
 provide a single torroidal magnet within the female with no magnet in or
 on the ferromagnetic male member. Various constructions of the female
 assembly have been suggested in which the female assembly presents a
 central opening in a housing that contains the magnet. A natural
 consequence of this arrangement is that dirt and debris can be attracted
 to and/or accumulate in this annular space. Thus, workers have suggested
 placing the magnet on or in the male member, but this also has
 disadvantages.
 One particular disadvantage that has been found when a male assembly having
 a projecting permanent magnet element is employed (for example, to a
 ladies handbag) is that the magnetic field emanating from the part having
 the magnet can erase all or part of the encoded information on the
 magnetic strip of credit and debit cards, identification badges, and the
 like. This occurs when the user of the bag having a closure flap opens the
 fastener, reaches inside the bag with the flap still loosely overlapping
 the side of the handbag and withdraws the credit card, passing it in close
 proximity to or touching the projecting magnet containing assembly.
 Likewise, if the user opens the fastener with the same hand that is
 holding a credit card (or any other card with a magnetic strip containing
 digital information) when the card is being returned to the interior of
 the bag the magnetic strip is potentially in position to be brought into
 contact with, or in close proximity to the projecting male element. As a
 consequence, all or part of the digital data can be erased, rendering the
 card unusable. Another disadvantage of having permanent magnetic
 characteristics on the projecting male member is the potential for debris
 to be attracted to the male member, thereby altering its contour and thus
 interfering with the operation of the locking mechanism in the female
 assembly, which often requires the locking mechanism to function by
 engaging a part within the female assembly with a portion of the periphery
 of the sidewall of the male member.
 It is therefore an object of the invention to provide an improved locking
 magnetic fastener in which the magnetic material is shielded and
 preferably resides in the female member.
 It is also an object of the present invention to provide an improved
 locking magnetic fastener which can be constructed with only one permanent
 magnet in its construction, and that remains securely locked without the
 need for springs or other biasing members, and which can be manually
 unlocked with a single motion that can be accomplished with one hand.
 Another object of the invention is to provide a locking magnetic fastener
 in which the opening in the female member is entirely or partially closed
 when the male member is removed to minimize the possible accumulation of
 debris in the interior of the female member.
 It is a further object of the invention to provide a novel locking magnetic
 fastener that is constructed from a minimum number of parts that are
 themselves easily and economically fabricated with conventional tooling,
 and that can be quickly and simply assembled without the need for complex
 equipment.
 Although the present invention has suitability for use in handbags and like
 items, it is yet another object of the invention to provide a two-part
 locking magnetic fastener which can be used as well for other purposes
 such as for maintaining drawers, doors and other closures in a secure
 locked relation upon engagement and which can be easily and reliably
 unlocked by a slide or pivot action which can, if desired, be directly or
 remotely activated.
 SUMMARY OF THE INVENTION
 The above objects and other advantages are provided by the novel
 construction and method of the improved locking magnetic fastener of the
 present invention, in which the permanent magnet serves the dual function
 of attracting and drawing the male and female assemblies into an engaged
 position under control of the locking member.
 In a particularly preferred embodiment of the invention, the permanent
 magnet produces magnetic attractions that are associated with, or emanate
 from, first and second regions or surfaces of the permanent magnet, and
 the male member and the Slide lock member are under the influence of
 different aspects of the attractive forces of the magnetic.
 In accordance with the present invention, a single permanent magnet, or
 multiple magnets, preferably of torroidal shape with a central opening, is
 contained in a housing as part of the female member. The female housing is
 provided with an exterior aperture which can be circular into which a
 portion of the male member extends. The female member has mounted therein
 a preferably non-ferromagnetic slide lock member which in a first position
 engages slide lock receiving means on the projecting male member to
 releasably maintain the male and female members in a secure, locked,
 mating relation. The non-ferromagnetic slide lock member preferably
 includes a ferrous contact member that, in a preferred embodiment, is in
 contact with or in juxtaposition to the permanent magnet in the engaged
 position. The slide lock member also has an aperture that in one preferred
 embodiment is partially aligned with the exterior aperture in the housing
 for the female member that receives the projecting male member when the
 two assemblies are moved into engagement. Thus, when the aperture in the
 slide lock is partially aligned, a portion of the exterior aperture of the
 housing is covered by the slide lock body. Upon insertion of the male
 member into the female member, a coming effect is created and the
 depending contact member moves with the slide lock member away from the
 permanent magnet against the attractive magnetic force to a second
 position that is still within the range of the attracting magnetic force
 between the magnet and contact member. As the male member is further
 inserted into the aperture of the female member, the slide lock member
 engages locking means formed in the male member thereby permitting the
 slide lock member to return to the first position with the contact member
 in contact with, or proximate to, the permanent magnet. A lock release is
 provided to move the slide lock member to the second position in order to
 release and remove the male assembly from the female assembly. In an
 alternative embodiment, the slide lock body completely covers the exterior
 aperture and must be displaced manually to at least an intermediate
 position to permit the cam surface to engage the cam follower surface to
 thereby move the slide lock member.
 As is well-known from the prior art, the use of a torroidal permanent
 magnet provides the desirable concentration of the magnetic field to
 attract the ferromagnetic portion of the male member into the interior
 chamber of the female member. Without wishing to be bound by any theory of
 operation, it has been observed that when the ferromagnetic contact member
 on the slide lock member is in contact with the permanent magnet, the
 axial holding power is reduced. When the surface of the male member which
 creates the coming effect engages the companion cam follower surface of
 the slide lock member, the slide lock member moves away from the first
 position and breaks the contact between the ferromagnetic contact member
 and permanent magnet. As a result, there is an apparent increase in the
 magnetic holding power of the male member and the attractive magnetic
 force drawing the male and female assemblies into mating relation. As the
 slide lock member is caused to move towards the second position, the
 female member continues to exert an attractive force that is essentially
 opposite to the mechanical force being applied by the cam surface of the
 male member. When the locking means is reached at the end of the cam
 surface, the slide lock member is drawn back to the first position by the
 attractive magnetic force between the ferromagnetic contact member and the
 permanent magnet.
 Thus, the apparatus and method of the invention comprehends a locking
 magnetic fastener in which a permanent magnet is positioned within and as
 part of the female assembly serves the dual function of (1) attracting and
 retaining the ferromagnetic male assembly in the female assembly, and (2)
 providing a biasing force for maintaining the locking member in the locked
 position. In a preferred embodiment of the invention, the magnet is a
 single permanent magnet which is torroidal and the magnetic field of the
 magnet alone and/or with associated elements provide the principal
 attractive force tending to draw and retain the projecting member of the
 male assembly into the central aperture of the female assembly. At the
 same time, a magnetic attraction exists between a ferromagnetic contact
 that forms a portion of slide lock member, and the slide lock member moves
 between first and second positions while at all times being subject to the
 attractive force within the female assembly, whereby it is attracted to a
 surface of the permanent magnet assembly.
 It is to be understood that as used in describing the invention in this
 specification and the claims that follow, the term "permanent magnet" is
 also intended to include magnet materials of all types and in all forms
 that are adaptable for use in providing the necessary magnetic forces to
 attract (1) the ferromagnetic material that forms a part of the male
 member, and (2) the ferromagnetic material that forms a portion of, or is
 attached to, the movable slide lock member and secures it in the locked
 position. Examples of other types of magnetic materials comprehended by
 the invention include compressed, sintered and machined forms; magnets
 produced from natural ores and those in which the magnetic force is
 induced; and the class of electromagnetic devices, such as solenoids.
 Electromagnetic devices can be activated by AC or DC, or be
 battery-powered, or solar powered, depending upon the nature of the
 installation of the locking magnetic fastener. As well, in the context of
 its operability as an attractive device, the "permanent magnetic" includes
 the assembly within which it is mounted.
 It should also be understood that there are other prior art magnetic
 fasteners which include magnets placed in both the male and female
 assembly to enhance their mutual attraction. The inclusion of a magnet in
 the male assembly is contemplated as being within the scope of the present
 invention, so long as the other aspects and features of the method and
 apparatus of the present invention are also present.
 The configuration and placement of the permanent magnet or magnets can
 vary, so long as the resultant magnetic force is sufficient to attract
 both the male member and cause the slide lock member to reliably move from
 an open or unlocked position to a closed or locked position.
 The type of material employed in the female assembly can also have a
 significant effect on the configuration of both the male and female
 assemblies and their construction. For example, the magnetic material
 neodymium is known to exert an attractive force on ferromagnetic materials
 that is much greater than that exhibited by the torroidal magnets commonly
 employed in magnetic fasteners sold for use on handbags and the like.
 Thus, the relative size of a torroidal magnet made from neodymium can be
 much smaller than that of a conventional magnet and still provide the
 same, or even a greater attractive force. The ability to reduce the size
 and/or modify the configuration of the magnet can permit the size of the
 female housing to be reduced, along with the contact and ferromagnetic
 element of the male member. For example, the permanent magnet can be
 provided with a relatively low or flat profile in a round or rectilinear
 configuration and without a central opening, i.e., non-torrodial, with the
 male member in touching contact to maximize the holding force when the
 male and female assemblies are completely engaged. Other changes and
 modifications to the structure and configuration of the elements forming
 the male and female assemblies and method of operation of the invention
 will be apparent to one of ordinary skill in the art.
 It is also to be understood that as used herein the term "ferromagnetic",
 as applied to an element or member, includes elements and members that are
 constructed or fabricated in whole or in part from a material that is
 subject to the attraction of a magnetic force, sufficient to perform the
 function described. It will also be understood that whatever the nature of
 the ferromagnetic material and the strength of the magnetic force, the
 attraction must be sufficient to draw the slide lock member into its first
 or locked position against the inertial force and the frictional forces
 imposed by the particular configuration of the female assembly of which it
 is a part.
 In the construction and assembly of the locking magnetic fastener of the
 invention, references to a slide lock member will be understood to
 comprise either (1) a single element that (i) either moves in a linear
 path or (ii) is pivot-mounted and moves in an angular path; or (2)
 multiple elements that move in either (i) linear paths, or (ii) angular
 paths.
 The male and female assemblies can assume various external configurations,
 including those dictated by aesthetic considerations, particularly where
 the invention is to be used with fashion items such as handbags, carrying
 cases and the like. For example, the aperture in the female member can be
 offset from the center of the housing to accommodate the design of the
 handbag, and/or to allow for the assembly and operation of the locking
 mechanism.

DETAILED DESCRIPTION OF THE INVENTION
 Referring to FIGS. 1-4, there is shown a first preferred embodiment of the
 locking magnetic fastener 10 of the invention with male assembly 20
 matingly joined to female assembly 40. Male assembly 20 is comprised of a
 base member 22 on which are mounted projecting male member 25 and male
 attachment means 35. The male projecting member 25 includes shank 26,
 forward end 28 that incorporates cam surface 30 terminating in lock means
 32, which, as shown in FIG. 2, is an offset shoulder formed between shank
 26 and the projecting surface of the larger forward end member 28. In this
 preferred embodiment, and as best shown in FIG. 3, the forward end 28 and
 shank 26 of projecting male member 25 are circular. As will be understood
 by one of ordinary skill in this art, these elements can be provided with
 other cross sections, including, without limitation, square, rectangular,
 hexagonal and oval. Such configurations are often dictated by aesthetics,
 the appearance and configuration of the article to which the fastener is
 to be applied, and other fashion factors, as well as source identification
 considerations. Other cross-sections are described and illustrated below;
 however, in the interest of convenience in illustrating and describing the
 invention, further embodiments will, for the most part, employ a circular
 configuration.
 Male member 25 further comprises male mounting means 33, which as best
 shown in FIGS. 1 and 2, can include a hollow, or semi-solid, or solid
 deformable rivet-like terminus that initially extends from shank 26 as an
 annular element. Attachment plate 36 is provided with a pair of arms 38
 that are normal to base member 22 for the purpose of securing the male
 assembly 20 to a handbag or the like, although other attachment means are
 contemplated. Attachment plate 36 is provided with a central aperture
 through which is passed mounting means 33, which is thereafter deformed to
 secure the elements together.
 With continuing reference to FIGS. 1-4, female assembly 40 is comprised of
 housing 42 having central exterior aperture 44 surrounded by annular
 collar 45 extending toward the interior of the chamber formed by the
 housing. As best shown in FIG. 2, collar 45 is provided with an outwardly
 extending flange 47 of an exterior diameter greater than the aperture 68
 in the slide lock member 60 to insure that these elements do not engage.
 The side walls of housing 42 include a plurality of projecting deformable
 tabs 46. With reference to FIG. 3, slide lock member 60 is comprised of
 body 61 which, in this embodiment, is provided with an offset aperture 68
 and has distal end 62 and proximal end 64. The distal end 62 of slide lock
 member 60 is provided with lock release means 70, which, in this
 embodiment, is in the form of a right-angle bend. Release 70 can be
 configured with such other surface or shape that can be utilized for
 conveniently and comfortably receiving the manually applied pressure of a
 fingertip or thumb to move the slide lock member. The offset aperture 68
 is partially aligned with central aperture 44 in housing 42 in a first
 position (I), and sufficiently aligned in a second position (II) to
 receive the forward end 28 of projecting member 25.
 With continuing reference to FIGS. 2-4 in the Preferred embodiment shown, a
 ferromagnetic contact member 66 is secured in depending relationship from
 the proximal end 64 of preferably non-ferromagnetic slide body 61. As best
 shown in FIG. 3, ferromagnetic contact 66 is arcuate, and its external
 periphery corresponds to that of the slide body to which it is secured,
 e.g., as by adhesive bonding, mechanical or other conventional fasteners
 used to join metal elements.
 With reference to FIG. 4, locking member 60 is shown in a second position
 (II) which is achieved by applying manual pressure to lock release means
 70, as by pressing with a finger or thumb. In this second position (II),
 ferromagnetic contact 66 is displaced from its first position (I) on or
 proximate to the exterior surface or periphery of permanent magnet 50.
 Lock means 32 is moved out of contact with slide body 61 at the periphery
 of offset aperture 68, and into alignment with the exterior aperture of
 housing 42, thereby allowing the previously restrained forward head of
 projecting male member 25 to be withdrawn from the interior of the
 housing.
 In the method of operation of the invention, the male and female assemblies
 are typically attached to the opposing faces of a handbag, briefcase, or
 other carrying case, and the user applies the necessary force by a finger
 or thumb on lock release means 70, which in turn causes the slide lock
 member 60 to move from its engaged position with the male member's lock
 means. At the same time, the user exerts a force generally in a direction
 normal to the slide lock movements, i.e., in the direction needed to
 disengage the male leading end 28 from the female to quickly and easily
 separate the two assemblies. As soon as the lock means clears the housing,
 the manual pressure is removed from release 70 and the attractive force
 between the slide contact 66 and magnet 50 causes the slide lock member to
 return to the first position (I). The female assembly is thus ready to
 again receive the male assembly without the need for coil, leaf or other
 types of spring or biasing members, all of the force being required to
 move the slide lock member being provided by the magnetic attraction. When
 the fastener is again to be mated and locked, the male assembly is moved
 into position adjacent the female assembly, and the attraction provided by
 the magnetic assembly in the central region of the housing 42 exerts a
 force on the ferromagnetic material of the forward end 28, which has the
 effect cf drawing the projecting male member 25 into the interior chamber.
 As the forward end 28 enters the exterior aperture 44, its cam surface 30
 engages follower surface 67 at the periphery of the offset sliding lock
 aperture 68, thereby causing the slide lock member 60 to move from its
 first position (I) towards its second position (II). Once the cam surface
 30 has passed through aperture 68, it reaches lock means 32 which allows
 slide lock member 60 to return to its first position (I) by virtue of the
 attractive force between contact 66 and the periphery of magnet 50.
 As is well known in the art, the housing 42 of the female and various other
 elements of the male and female assemblies are of either ferro- or
 non-ferromagnetic material so as to protect the parts, assist in the
 operation of the device and modify magnetic attraction. Thus, In this
 first preferred embodiment, it will be understood from FIGS. 2-4 that the
 body 61 of lock member 60 is in contact with the adjacent surface of
 magnet 50, and the body is therefore a substantially non-ferromagnetic
 material, and that the coefficient of friction between these two elements
 is to be minimized to insure smooth sliding movement to facilitate the
 return of contact 66 to its position on or proximate to magnet 50. Slide
 body 61 can be fabricated from a smooth, rigid, low friction engineering
 plastic, or, if fabricated from metal, provided with a smooth, polished
 surface, or coated with a low friction material such as PTFE (TEFLON.RTM.
 from the Dupont Company). The choice of ferro- and non-ferromagnetic
 materials can also be dictated by aesthetic considerations, but the above
 factors will apply.
 It will also be understood that ferromagnetic contact 66 can be formed from
 a separate element as described above and attached to the proximal end 64
 of slide body 61, or can be formed as an integral element of lock member
 60, as by appropriately bending and shaping the proximal end normal to the
 body and providing it with a ferromagnetic plating, or securing a
 ferromagnetic element to the formed depending surface. Alternatively, the
 entire slide lock member can be fabricated from a ferromagnetic material
 and, as shown in FIG. 5, maintained in spaced relation from the magnet 50
 by non-ferrous slide plate 80. Slide plate 80 can be fixedly mounted in
 the interior chamber in contact with magnet 50, or mounted for movement
 with slide lock member 60. In either event, the surface of slide plate 80,
 which is subjected to relative movement, should exhibit a low coefficient
 of friction for the reasons stated above.
 It will also be understood by one of ordinary skill in the art hat the cap
 52 of the female fastener assembly can be eliminated and other known
 mounting means employed. In order to provide enhanced attraction and
 holding power between the assemblies, the female base member 48 can be
 made of ferromagnetic material and the projecting male member 25
 configured to contact the base member when the assemblies are engaged.
 It will also be understood, that methods and constructions known to the
 magnetic fastener prior art to enhance the attraction between the male and
 female assemblies and the holding force of the joined assemblies can be
 adapted for use with the locking magnetic fastener of the invention.
 With further reference to FIG. 5, there is shown spacer ring 81 positioned
 between housing 42 and slide lock member 60 having an aperture
 corresponding the exterior aperture 44. Spacer 81 can be of ferromagnetic
 or non-ferromagnetic material. It can be utilized to stabilize or guide
 the movement of the slide lock member. In the embodiment illustrated by
 FIG. 5, the contact 66 is a separate element affixed to the proximate end
 of the slide body 61. Alternatively, the ferromagnetic slide lock member
 can be machined or otherwise formed or shaped from a single piece of
 stock, thus providing a unitary constructions.
 It will be understood from the embodiment illustrated in FIG. 5 that the
 slide plate 80 is provided with a central aperture corresponding to the
 forward end 28 of the projecting male member 25 to insure an
 interference-free passage and the engagement of the locking means. male
 member 25 to insure an interference-free passage and the engagement of the
 locking means.
 It will be understood from the method of operation illustrated in FIG. 5,
 that alternative constructions in which the surface of the slide lock body
 61 opposite the interior top wall of housing 42 can be provided with one
 or more projecting portions to facilitate sliding contact between these
 two members. For example, the surface of the slide body 61 can be provided
 with corrugations, ribs and/or spaced apart raised areas of other
 configurations shown in black box form 81 a in FIG. 5a to contact the
 interior surface of housing 42 to stabilize the slide lock member while it
 is stationary or during movement, and at the same time, to minimize the
 frictional forces between these two parts.
 The interior chamber formed by housing 42 and base 48 can be of any
 convenient size and, as noted above, of a simple utilitarian configuration
 to protect and define the range of movement of the slide lock member; or
 the configuration can be ornamental or so shaped as to provide an indicia
 which permits recognition of the device from a source. It will be
 understood that the interior chamber must be sufficient to accommodate the
 movement of slide lock member 60 between its first position (I) and its
 second position (II). The range of movement can be determined by
 interfering contact between the proximal end of lock member 60 with the
 interior of housing 44, or other structure provided specifically for this
 purpose (not shown); and/or by contact with lock release means 70 with the
 exterior of housing 42 in the vicinity of side wall opening 47.
 If desired, additional structure can be provided to control and direct the
 movement of slide lock member 60. For example, as illustrated in FIG. 6, a
 guide 84 comprising base 86 and flanking arms 88 can be secured to the
 female base 48 as is, for example, shown in FIGS. 7 and 8, to insure
 linear movement between the first and second positions.
 In an alternative preferred embodiment shown in FIG. 9, a contoured
 retaining guide 90 is provided by molding and/or machining a non-ferrous
 material. Guide 9 is preferably provided with a base 98 having mounting
 aperture 98 and surrounded by retaining wall 94 that provides an area for
 receiving magnet 50, which in this embodiment is torroidal but could be of
 any other desired functional configuration. Upper surface 95 is provided
 with guide channel 96 adapted to receive the slide lock member 60 in
 sliding relation. As will be apparent to one of ordinary skill in the art,
 retaining guide 90 can be provided in a variety of alternative
 configurations, including those in which the retaining wall 94 completely
 surrounds magnet 50 (not shown), and provides a pail of guide channels 96.
 With further reference to FIG. 9, attachment means, which can include
 ferromagnetic annular member 52, is employed to secure guide 90 to female
 assembly attachment means 55. FIGS. 9 and 10 further illustrate the final
 assembly of this embodiment.
 With reference to FIGS. 12-14, there is illustrated a preferred embodiment
 of the slide lock member 60 in which the cam follower surface 67 that
 defines slide aperture 68 is bounded by beveled throat 73. The purpose of
 this beveled region is to facilitate the entry of the projecting male
 member into aperture 68 and its eventual locked, mated relation with
 female assembly 40. As shown in the corresponding views of FIGS. 13 and
 14, the method of operation and engagement of the locking means with the
 slide plate is analogous to that described above in connection with FIGS.
 1-4. The beveled area of the slide lock member of this embodiment can be
 conveniently and efficiently formed by appropriately configured metal
 stamping dies. As shown in FIG. 14, a guide 84 having upstanding arms 88
 is provided to limit the directional movement of locking member 60 from
 its first position (I) to its second position (II), shown in phantom.
 From the above description of FIGS. 12-14, it will also be understood that
 housing 42 can also be formed with a beveled area surrounding the exterior
 aperture 44 to further guide and facilitate the movement of the male
 member into the female assembly.
 One preferred arrangement for mounting the locking magnetic fastener
 invention is shown with reference to a handbag, briefcase, or the like in
 FIGS. 15-17. The female member 40 is attached to the interior of closure
 flap 104 so that the lock release 70 is proximate the free edge of the
 flap. As indicated in FIG. 15, the lock release 70 is displaced inwardly,
 and when the flap is closed, as shown in FIG. 16, the locking mechanism is
 not visible to a casual observer of the exterior of the bag. Referring to
 FIG. 15, male assembly is mounted on an opposing wall 102 of the bag 100
 in an appropriate position to mate with female member 40. The relationship
 between the elements of the bag and the slide lock member is shown in the
 cross-sectional view of FIG. 17, it being understood that the male
 attachment means 35 and female attachment means 55 are employed to secure
 the respective assemblies to the leather or textile material in accordance
 with well known practices in this art.
 With reference to FIG. 17, in order to open the bag, a finger is placed
 between the flap and front wall, and the lock release 70 is pressed
 towards the cover while lifting up on the adjacent edge of flap 104 to
 withdraw the projecting male member from the interior chamber.
 In the alternate embodiment shown in FIG. 18. a portion of the female
 assembly is mounted on, or projects through, flap 104, and the lock
 release 70 remains under the flap and is activated as described above. In
 the embodiment illustrated in FIG. 18, it will be understood that the
 exterior element is a decorative feature whose placement and configuration
 is determined by aesthetic or source identifying considerations, in as
 much as the functional elements of the female assembly are located on the
 interior of the flap. As will also be appreciated by one of ordinary skill
 in this art, the relative positions of the male and female members, as
 shown in FIGS. 15-17, can be readily reversed. The female assembly,
 including the lock release 70, can also be mounted on the exterior of flap
 104 by changing the location and configuration of attachment means 55 (not
 shown) and providing flap 104 with an appropriately aligned aperture.
 A further alternative embodiment for the assembly of the invention is shown
 in FIGS. 19 and 20. A combination guide and female attachment means 20 is
 formed from an integral base 86 having a pair of deformable attachment
 arms 58 extending outwardly and a pair of guide arms 88 offset and
 extending into the interior chamber. An intermediate plate 120 fabricated
 from an insulating material is provided with a pair of slots for receiving
 arms 88 and a central aperture 124 for receiving mounting means 52. In
 this preferred embodiment, intermediate plate 120 prevents the magnet from
 making contact with the base member and causing it to exhibit magnetic
 properties. In this embodiment, the housing 42 (not shown) is knurled over
 and around the periphery of intermediate plate 120 in order to seal the
 female assembly. As will be understood by one of ordinary skill in the
 art, the configuration and method of joining the housing and base elements
 can be varied.
 In yet another embodiment as shown in FIG. 21, the guide body 61 is
 provided with a pair of depending arms 78 which displaces slide lock
 member 60 from coming in to contact with magnet 50 when these two elements
 are assembled into the female assembly 40.
 In a further modified configuration illustrated in FIG. 22, the female
 attachment means 55 is provided with at least two retaining arms 59 which,
 as shown, are contoured to the periphery of magnet 50. In this embodiment,
 retaining arms 59 can serve to support body 61 of slide lock member 60 in
 a position that is displaced from the surface of magnet 50, and is
 preferably fabricated from a non-ferrous material, as by metal stamping
 methods well known in the art. Alternatively, as shown in FIG. 23, the
 terminal ends 59A of retaining arms 59 can be folded over above magnet 50
 to provide a broader surface upon which slide lock member 60 can move.
 As has been explained previously, the particular configuration of the
 projecting male member 25 and the slide lock aperture 68 can be varied.
 For example, as shown in FIGS. 24 and 25 respectively, apertures 68 can be
 provided in a rectilinear configuration or a T-shaped configuration. As is
 shown, in each of these embodiments, when the aperture is moved from first
 position (I) to second position (II), the locking means of forward end 28
 is no longer engaged and can be removed from the aperture. As will also be
 understood from the above description and the prior art, the configuration
 of the projecting male member, and particularly its forward end 28, can
 also be varied to correspond to the exterior aperture in housing 42 as
 well as that of the aperture 68 in slide lock 60.
 To further enhance the security of the locking magnetic fastener, in a
 preferred embodiment, a safety release is incorporated into the slide lock
 member. The function and purpose of the safety release is to inhibit the
 disengagement of the locking means as a result of an inadvertent movement
 of the projecting release 70. This result can be achieved by a number of
 mechanical means, including detents, slots, interfering offsets, and the
 like. By way of example, and with reference to FIGS. 26 and 27, there is
 shown a portion of mated male assembly 10 and female assembly 40 of
 construction similar to that described above in connection with FIGS. 1-4.
 Slide lock member 60, shown in the locked first position (I), is provided
 with a projecting safety release that makes interference contact with the
 exterior of housing 42 proximate the side wall opening 47. The interfering
 contact between safety release 72 and housing 42 prevents the displacement
 of embodiment 60 from its locked position (I) by a force applied in the
 same plane as the lock member. In order to move slide lock 60, a force
 generally normal to the plane of the locked member must be applied to the
 proximal end that extends from the housing. In this embodiment, it will be
 understood that the tolerances in the assembly and/or the resilience of
 the material from which lock member 60 is fabricated will be determinative
 of the amount of force that must be applied to disengage safety release
 72. As shown in FIG. 27, after the generally normal force has been
 applied, the slide lock member 60 can then be urged towards the housing.
 From the above description of the safety release illustrated on FIGS. 26
 and 27, it will be understood that a similar feature can be included to
 retain the slide lock member in the open position. For example, a retainer
 member (not shown) can be provided in the body 61 that engages the
 interior surface of the housing adjacent the opening 47. The retainer is
 moved into engagement by applying a manual force that is normal to the
 direction of movement required to release the lock means. Thus, utilizing
 the retainer member to prevent the slide lock member from returning to the
 first position permits the male assembly to be moved into and out of the
 female assembly by applying a manual force to overcome the magnetic force
 that holds the two assemblies in place.
 In a further embodiment of the invention, the movement of the lock member
 60 from its locked first position (I) to its unlocked second position (II)
 can be accomplished by a pulling movement rather than the pushing movement
 described in connection with the previously described constructions and
 methods. An example of such an apparatus is shown in FIG. 28 where the
 ferromagnetic contact 66 is attached to lock body 61 between the slide
 lock aperture 68 and the distal end 62. With further reference to FIG. 28,
 it will be seen that the force applied to unlock the fastener of this
 embodiment is applied in a direction opposite to that of the embodiments
 previously described. However, the same considerations apply to the size
 and placement of element 66 in this configuration, i.e., that the
 attractive force between contact 66 and magnet 50 must be sufficient to
 cause the lock member to return from the withdrawn position (I) to the
 retracted locked second position (II).
 In another embodiment, the safety release can be formed by providing a slot
 in the proximal end of the slide lock member 60 at a position that
 corresponds to the adjacent housing wall 52 and providing a biasing force
 to cause the slot to engage the side wall when lock member 60 is in the
 first position (I). The safety release is disengaged by applying a force
 laterally to the edge of the lock member 60 until the slot is free of the
 housing side wall.
 It will be understood that the slide lock member 60, as well as other
 elements forming the improved locking magnetic fastener are shown to be of
 symmetrical configuration for convenience of assembly of the device during
 manufacture to avoid the need for special alignment. However, there is no
 requirement that the parts be symmetrical, and design considerations,
 including aesthetics, can be accommodated with asymmetrical elements. Some
 exemplary alternative design configurations are illustrated in certain of
 the embodiments which follow. Furthermore, as will be apparent to one of
 ordinary skill in the art, additional modifications can be incorporated
 without departing from the spirit or scope of the invention as defined by
 the claims.
 With reference to FIG. 29, there is shown one embodiment of a pivotally
 mounted slide lock member 160 in engaged locked relation with the male
 member 25. Slide lock member body 162 is conveniently produced by die
 stamping or machining from the materials described above. It is formed
 with aperture 168 defined in part by cam follower surface 167 that
 contacts forward end 28 of male member 25, thereby causing arcuate
 deflection to position (II) around pivot mounting pin 169 that is secured
 to the female housing. The slide lock member body 162 is returned to its
 original position (I) upon engagement of the locking means by the magnetic
 attraction of a ferromagnetic contact 166 secured to body 162 and the
 permanent magnet 50 (not shown). The proximal end 164 extends from the
 housing and is provided with release 170 which can be moved to rotate the
 aperture 168 into alignment to permit the male member to be withdrawn from
 the female assembly.
 In a further preferred embodiment, as illustrated in FIG. 30, the amount of
 ferromagnetic material in the projecting male member can be reduced. As
 illustrated, the proximal end 25A of projecting male member 25 is formed
 with a non-ferromagnetic material. Depending upon whether the overall
 configuration of the forward end 28 is a relatively flat ellipsoid or a
 more elongate paraboloid, the non-ferromagnetic material can comprise a
 greater or lesser proportion of the forward end 28. The non-ferromagnetic
 member can be die cast from a zinc and lead alloy, machined from brass,
 copper, or formed of other metal, and can also alternatively be of molded
 plastic. It can be joined to the distal ferromagnetic portion of forward
 end 28, or to shank 26 by adhesive, by threaded engagement, or by integral
 casting. Since the purpose of providing a non-ferromagnetic material at
 the proximal end of male assembly 25 is to minimize attraction that may
 form in the housing 42, the amount of ferromagnetic material retained in
 the male assembly 25 is to be sufficient to provide the desired attractive
 force that will cause the male assembly to be drawn into mating relation
 with the female assembly. The determination of the relationship between
 the size and configuration of the non-ferromagnetic proximal end member
 and that of the ferromagnetic material in the projecting male member 25 is
 within the skill of the art.
 With reference to FIG. 30, there is shown a portion of the projecting male
 member 25, including shaft 26 joined to leading end 28. The leading end 28
 is fabricated in whole or in part of a ferromagnetic material, i.e., a
 material that will be attracted into an appropriate aligned position and
 drawn by magnetic attraction to the interior of the chamber 43 formed by
 housing 42. These desired results can be achieved by providing a
 ferromagnetic material in combination with a non-ferromagnetic material,
 e.g., in a configuration where the tip section 29 is of a
 non-ferromagnetic material, and optionally extends as a sheath or housing
 31 over a core 34 of ferromagnetic material. Tip section 29 can be of a
 low friction and/or resilient polymeric material that will not mar or
 scratch the exterior surface of the housing 42 and slide lock member body
 61 that is exposed in exterior aperture 44. The use of a low friction
 material for tip section 29 and, optionally sheath 31, will advantageously
 facilitate the movement of the corresponding cam surface 30 during its
 contact with cam follower surface 67 prior to engagement of the lock means
 32. The use of contrasting materials, colors and finishes can be employed
 to provide striking aesthetic effects and to make the male member of FIG.
 30 more attractive, or to distinguish the product of one source from
 another.
 It will also be understood by those familiar with the art that contact
 between the ferromagnetic material of forward end 28 and the ferromagnetic
 cap on female mounting means 52 affects of the magnetic attraction between
 the male and female assemblies. The ferromagnetic cap 52 preferably does
 not contact magnet 50, because that will reduce the attractive and holding
 force between the male and female assemblies. Alternatively, the cap of
 female mounting means 52 can be formed of a non-ferromagnetic material.
 It is also to be understood with reference to the illustrative drawings
 that the ferromagnetic contact 66 is shown in spaced-apart relation to the
 base 48, which is preferably a ferromagnetic material. In the construction
 and operation of the devices of the invention, these elements can be in
 touching sliding contact if base 48 is a non-ferromagnetic material. In
 those constructions where a surface of contact 66 is in touching relation
 with the surface of base 48, a low coefficient of friction between these
 elements is desired, and can be achieved as by polishing one or both
 surfaces or providing an intermediate member, i.e., a slide pad 99 of low
 friction material, such as PTFE, as shown in FIG. 21. In this embodiment,
 a non-conducting slide pad 99 can serve as an insulator where base 48 is
 of ferromagnetic material.
 In the interests of clarity, the illustrative figures show a space between
 the tip of male assembly 25 and the structure of the female assembly.
 However, as will be apparent to one of ordinary skill in the magnetic
 fastener art, if the tip portion of projecting male member 25 is a
 ferromagnetic material, the overall attraction of the male assembly to
 female assembly can be enhanced by providing touching contact with the
 ferrous cap 52. Various other features and constructions that are
 generally known and employed in the magnetic fastener art, such as an
 axial orifice 57 in the mounting means 52 as shown in FIG. 2, can be
 incorporated into the locking magnetic fastener of the invention.
 One or both ends of the slide lock member 60 can be supported and
 stabilized by to providing an appropriately-sized, close-fitting opening
 between female assembly housings in which a lower outer cup is engaged in
 a snap-fit, or is otherwise secured to a close-fitting, upper inner cup.
 By aligning the openings in the inner and outer cups, the extending distal
 end 62 is supported and its movements stabilized by the adjacent sidewalls
 of the cups in a first preferred embodiment. In a second alternative
 embodiment, the opposite or proximal end of the slide lock member body 61
 is extended to project from a similar supporting opening (not shown)
 formed in the opposite sidewalls of the assembled cups.
 As shown in FIG. 31, the housing 42 can take the form of an inner cup that
 is provided with a plurality of projecting tabs 76 and a sidewall opening
 47 that is dimensioned to closely define the path of the projecting distal
 end 62 of slide lock member 60. A close-fitting outer cup 49 is provided
 with a corresponding number of slots 78 for receiving tabs 76, which as
 best shown in FIG. 32, are then folded over to secure the two cups
 together. As also shown in FIG. 32, the rim 79 of outer cup 49 is
 positioned to support the distal end 62 of body 61 in sliding relation,
 and in combination with sidewall opening 47, define and limit the movement
 of slide lock member 60 between the closed or locked position (I) and open
 position (II).
 As will be understood from the above description and the figures that form
 a part of this disclosure, the configuration and design, if any, of the
 housing 42 can be varied without departing from the spirit and scope of
 the invention. As will be apparent to one of ordinary skill in the art,
 the circular or cylindrical configuration of the housing illustrated in
 the accompanying drawings reflects a shape that is easily and
 inexpensively manufactured and that can efficiently accommodate the
 torroidal magnet of the preferred embodiment. However, a housing can be
 provided in an oval, rectilinear or other desired external configuration
 based upon (i) considerations of design harmony with the product or other
 environment in which the locking magnetic fastener is to be used; (ii) a
 desire to affix or reproduce a trademark or other decorative element on
 the housing; or (iii) the use of magnetic materials in other than a
 torroidal shape, e.g., one or more bar magnets.
 As will also be apparent to one of ordinary skill in the art, the slide
 lock member can be oriented with respect to the housing in any of a
 variety of ways. For example, the projecting portion of the distal end can
 appear to be aligned with a diameter of a circular or cylindrical housing,
 or it can cut across the circle as a chord, and can move or rotate about a
 pivot point. Likewise, with a housing that appears in plan as a square,
 rectilinear, trapezoidal or other such shape, the slide lock member can
 project at a right angle to bisect the shape or be displaced from a
 midline; or it can project at an angle that appears to be acute or oblique
 angle to a principal axis; or extend diagonally from a comer of the
 housing and move in a linear or rotational path with respect to the
 magnet. Additionally, the exterior surface of the housing can be provided
 with rounded or beveled corners; be corrugated or otherwise textured for
 strength or decorative effect; and be engraved, tooled and otherwise
 superficially modified in accordance with the desires i)f fashion
 designers and current trends.
 As will also be apparent from the description provided herein and the
 illustrations of the drawings, the size and configuration of the external
 aperture 44 in the housing and the slide lock 68 can be varied. For
 example, the aperture 44 can be larger, smaller or approximately the same
 size as that of the slide lock aperture.
 With reference to FIGS. 33 and 34, there is illustrated a further preferred
 embodiment to of the invention in which the ferromagnetic contact 66
 depends from the slide lock member 60 at a position that is on the
 interior of the torroidal magnet 50. When in the closed or locked position
 (I) shown in FIG. 34, ferromagnetic contact 66 is attracted to the
 interior surface of magnet 50. When the release 70 is advanced to the
 unlocked position (II), the projecting male member 25 is released and can
 be separated from the female assembly; upon the removal of manual pressure
 on lock release 70, the attractive force between contact 66 and the
 adjacent surface of magnet 50 is sufficient to cause the slide lock member
 60 to return to the closed position (I).
 As will be understood from the above description and the embodiments
 illustrated in the figures described, the configuration of the body 61 of
 the slide lock member 60 can assume any of a variety of configurations,
 which variations may be determined by convenience of manufacture, a desire
 to reduce the materials consumed, the configuration of the exterior
 housing (which may include aesthetic considerations), and the like. In the
 embodiments previously described, the lock means 32 of the projecting male
 member is engaged and secured by only a portion of the slide look member
 body 61 that is overlapped by the projecting shoulder of the forward end
 28. Thus, portions of the slide lock member body which are not aligned
 with exterior aperture 44 in housing 42 can be eliminated. However, in
 making such modifications, it must be kept in mind that the rigidity,
 integrity, tensile strength and sliding mobility of the mechanism must not
 be impaired. In this regard, reference is made to FIG. 35 in which the
 body 61 of slide lock member 60 is generally circular with a rectilinear
 distal end 62. In the embodiment illustrated, it will be understood that
 the diameter of the shank 26 will have an effect on the area of the
 overlapping engagement or contact between the two elements. As
 illustrated, there is an overlap of almost 50% around the periphery of the
 slide lock aperture 68. In the alternative embodiment illustrated in FIG.
 36, about 30% of the material forming the circular body 61 has been
 removed, thereby providing a material savings in the construction of the
 invention. Since the housing 42 conceals all but a small section of the
 body 61 when the male and female members are separated, the difference in
 configuration of the body 61 will not be apparent to the user. It is also
 to be understood that other variations in configuration can be adopted.
 For example, the curvilinear configuration of slide lock member 60 shown
 in FIG. 36 can readily to adapted to a rectilinear for m without adversely
 affecting the method of operation and effective functioning of the locking
 magnetic fastener of the invention.
 In a further preferred embodiment of the invention, a plurality of locking
 positions are provided to permit the male assembly to be securely engaged
 within the female assembly, while at the same time providing a device that
 will allow an object, such a handbag or carrying case to be filled to a
 greater capacity. One such aspect of this preferred alternative embodiment
 of the invention is schematically illustrated in FIG. 37, where the shank
 26 of projecting male member 25 is provided with a plurality of cam
 surfaces 30 and intermediate lock means 32. When attached to a ladies
 handbag having an overlapping closure flap, the stand-off distance
 provided by the partial insertion of the male member as illustrated in
 FIG. 37 will provide for additional carrying capacity in the body or
 pocket of the handbag. By applying additional force to the exterior of the
 flap on which the male assembly is mounted, the cam follower surface 67
 will ride up over the consecutive cam surfaces 32 until, as shown in
 phantom, the projecting male member is fully inserted in the final
 position.
 In the embodiments of the locking magnetic fastener described above, the
 slide lock member was formed as a single or unitary element that moved in
 a generally linear path or, when pivotally mounted, in an arcuate path; in
 either case, the slide lock member being returned to its closed or locked
 position (I) under the force of attraction between the magnetic material
 and a ferromagnetic contact which was attached to or formed as a part of
 the slide lock member. In the further preferred embodiments of the
 invention that are described below, the slide lock member is comprised of
 two elements which cooperate in movement and function to engage and lock
 the male assembly in a secured position with respect to the female
 assembly. As will be described in more detail with reference to specific
 embodiments as illustrated by the figures, each of the elements of the
 slide lock member are provided with a ferromagnetic contact which, in the
 closed or locked position (I), are in contact with or proximate to the
 magnet or magnets contained in the interior chamber of the female
 assembly. When these elements are moved away from the closed or locked
 position (I), either by the cam action of the projecting male member or by
 manual force applied to release the lock, the effective magnet attraction
 force is sufficient to return the elements to position (I). In the
 preferred embodiments which follow, the slide lock member is comprised of
 two elements arranged in opposing relation and pivotally mounted, either
 at their respective proximal or distal ends. Manual force to displace the
 elements from position (I) is provided, for example, by simultaneously
 pressing the projecting release for each between a thumb and forefinger,
 the elements returning to their previous position by magnetic attraction
 when the manual force is removed. In this regard, it should be noted that
 the slide lock member elements are retained in a first, fixed position (I)
 and returned from a second, displaced position (II) in response to the
 attraction of a permanent magnet fixed in position in the interior chamber
 of the female assembly.
 One such example of this further preferred embodiment is illustrated in
 FIG. 38 in which a pair of slide lock members 60a and 60b are pivotally
 mounted at their respective distal ends on pivot pin 72 that is secured to
 base 48 by any appropriate means, including welding, a threaded fastener,
 riveting, or the like, such methods being well known to those of ordinary
 skill in the art. As shown in FIG. 39, pivot pin 72 is secured to base 48,
 as by deforming the head of the projecting end. The accurately moving
 elements 62a and 62b are supported in position by pivot pin shoulder 73
 and deformable head 74. The assembly can be further stabilized by
 inclusion of mounting washers (not shown) positioned above and below the
 moving elements 60a and 60b, which washers can have a low friction surface
 to facilitate their easy movement. This embodiment is further illustrated
 in the cross-sectional view of FIG. 40 which shows the ferromagnetic
 contacts 66a and 66b adjacent opposing sides of torroidal magnet 50 in
 position (I). As will be understood from the explanation and descriptions
 which have been previously provided, when the releases 70a and 70b are
 pressed together as schematically illustrated in FIG. 41, the opposing
 elements of the body 61a and 61b are moved outwardly to allow the
 projecting male member 25 to be removed while the slide lock member is in
 position (II). Upon removal of the compressive force from the release
 elements 70a and 70b, the force of magnetic attraction between magnet 50
 and ferromagnetic contacts 66a and 66b returns the opposing elements to
 the closed position (I).
 A further embodiment of this aspect of the invention is illustrated in
 FIGS. 42-45, in which opposing slide lock members 62a and 62b are pivoted
 at their proximal ends about pivot pin 72. In this embodiment, as best
 shown in FIGS. 42 and 44, the release mechanism is formed from independent
 release cam arms 474a and 474b which are mounted on release pivot pin 472
 for pivotal movement in response to opposing forces applied to releases
 70a and 70b. As best shown in FIG. 44, when the force is applied to move
 the releases towards each other, the opposing ends of the release arms
 471a and 471b rotate against the surface of is the release cam followers
 476a and 476b to move the opposing body members 61a and 61b into open
 position (II) as shown in FIG. 44. As best seen in cross-sectional view
 FIG. 45, the corresponding ferromagnetic contacts 66a and 66b are moved
 away from magnet 50, but still within the range of the magnetic attraction
 force, so that upon removal of the force from releases 70, the contacts
 are moved with their corresponding slide lock members 60a and 60b to the
 closed position (I). As will be apparent to one of ordinary skill in this
 art, the particular mechanism for pivoting and opening the opposing slide
 lock members can be varied without departing from the general teachings of
 the invention. If desired, more than two opposing slide lock members can
 be incorporated into the locking magnetic fastener of the invention. For
 example, two pairs of opposing slide lock members oriented at right angles
 to each other can be arranged to provide an aperture that is engaged by
 the leading end of the projecting male member to move all four of the
 elements by the same effective cam action described in connection with the
 earlier embodiments, e.g., of FIGS. 1-30.
 It will be understood from the illustrative examples depicted in FIGS. 36
 and 38-45 that the aperture 68 in the slide lock body 61 need not be
 symmetrical or even completely surround the male member in the engaged
 position. similarly, it will also be understood from the present
 description and examples that the size and configuration of the slide lock
 aperture need not conform to that of the external aperture 44 in housing
 42, or to any particular configuration of tea permanent magnet, or
 magnets, 50. Thus, aperture 68 can be larger than the central opening if a
 torrodial magnet is employed, its size, configuration and position being
 determined by its operative relationship with the projecting made member
 25. This applies equally to assemblies in which a flat plate permanent
 magnet is employed, or one or more bar magnets are positioned in the
 female assembly to attract and hold the male assembly in the engaged
 position by as shown in FIG. 38a which shows two bar magnets 50a in black
 box configuration.
 A further enhancement to the operation of the locking magnetic fastener of
 the invention is illustrated in FIG. 46, where there is shown a spacer in
 the form of an annular spacer member 490 surrounding the exterior aperture
 44 of housing 42 and secured in position on the interior wall of the
 housing and above the surface of the body 61 of the slide lock member.
 This annular spacer 490 can be fabricated from a ferromagnetic or
 non-ferromagnetic material and can function to limit the movement of slide
 lock member 60 in the direction of the housing 42. If produced from a
 ferromagnetic material, spacer 490 will also serve to enhance the magnetic
 attraction and guide the projecting male member into alignment for
 insertion and retention in the female assembly. The spacer can be secured
 in position by adhesives, mechanical fasteners, or other means known to
 those familiar with the art.
 In order to provide a locking magnetic fastener in which the female
 assembly is completely sealed against the incursion of dirt and debris
 when the male assembly has been removed, exterior aperture 44 in housing
 42 is completely covered by a portion of the distal end 64 of slide body
 61. In this regard, reference is made to FIGS. 46-49 in which the
 projecting male member is provided with a rectilinear leading end 28,
 which is adapted to pass through the exterior aperture 44 of housing 42.
 It will be understood from FIG. 46 that the specific configuration of the
 projecting male member and the receiving exterior aperture in the female
 assembly can be modified, e.g., by configuring the aperture to match or
 conform closely to the corresponding maximum cross-section of the leading
 end 28 of the projecting male member. Thus, the aperture 44 of FIG. 46 can
 be of a rectilinear configuration. As is shown in FIGS. 47-49, the rim
 around aperture 44 is rounded or beveled to facilitate the entry of the
 male member 25. Additionally, the housing 42 can be shaped to form a
 concave or beveled surface around aperture 42 to further guide the male
 member into entry position.
 As shown in the cross-sectional view of FIG. 4E, the cam surface 30 of the
 male member cannot engage the cam follower surface 67 when the slide lock
 member is in the completely closed position. To initiate such contact, it
 is necessary to manually apply force to release 70 thereby moving slide
 lock aperture 68 partially into alignment with exterior aperture 44, while
 at the same time advancing tip portion 29 of the projecting male member
 towards aperture 68. Thereafter, the method of operation of this
 embodiment is the same as in the previously described embodiments. As
 shown in FIG. 49, the slide lock body engages the lock means of the
 projecting male member in an intermediate locked position (III). It will
 also be noted that the ferromagnetic contact 66 is partially displaced
 from magnet 50, but still within the effective range of the magnetic
 attractive force to maintain the slide lock member in engagement against
 the shank 26 of the projecting male member.
 A further embodiment of the invention, in which the exterior aperture in
 the housing of the female assembly is completely closed when the male
 member is removed, is illustrated in FIGS. 50-56. Although this embodiment
 is similar in its exterior appearance to the male and female assemblies
 described above in connection with FIGS. 47-49, this embodiment has the
 advantage of requiring no manual intervention to initiate movement of the
 slide lock member in order to permit the leading end 28 of the projecting
 male member to enter the interior chamber. With reference to FIGS. 51-53,
 it will be seen that the slide lock member 560 is formed without an
 aperture corresponding to the exterior aperture of the housing 42 and is
 mounted for rotational movement on pivot pin 569, which is shown in the
 cross-sectional view of FIG. 52 as being of generally square
 cross-section, but with a spiral or twist running along its length. A
 corresponding guide aperture 561 is provided in slide lock member 560
 which fits closely, but in sliding relation, i)n the shaft of pivot pin
 569. With reference to FIG. 51, when the leading end 28 of the projecting
 male member 25 is brought into contact with the exposed exterior surface
 of slide lock member 560, the force applied at right angles is in part
 converted to a rotational movement as a result of the movement along the
 twisted shaft of pivot pin 569. In other words, the entry of the male
 member has the effect of deflecting the slide lock member out of its
 closed position (I); once the tip portion 29 of the male member has passed
 the edge of the slite lock member, the cam action commences, and the slide
 lock member continues to ride up the cam surface 30 until it reaches the
 lock means 32, at which time it falls in position to secure the male
 member. During this movement, the lever 565, which is pivotally mounted by
 means of fastener 566 adjacent the periphery of the slide lock member, is
 caused to move and the ferromagnetic contact 66 is drawn away from the
 interior surface of lorroidal magnet 50 but remains in the field of
 magnetic attraction. As shown in the detail of FIG. 56, the periphery of
 the slide lock member is released from engagement with the lock means 32
 by a manual force applied to the release 570 which, with a portion of the
 distal end 562 of lever 565, projects from the housing 42, thereby
 allowing the male member to be withdrawn. When the manual force is
 released, the attraction between contact 66 and magnet 50 causes the lever
 to be returned to the closed position (I), which necessarily brings the
 slide lock member 560 back into position via a spiral movement to
 completely close the exterior aperture, and in a position that is in close
 proximity to, or touching, the interior surface of housing 42. In an
 alternative mode of operation, the slide lock member 560 can be partially
 displaced to permit engagement of the cam and cam follower surfaces in a
 manner similar to that described in connection with the method of
 operation of the embodiment of FIGS. 46-48. Thus, the structure of this
 embodiment can be operated with or without manual intervention to initiate
 the entry of the male member into the female assembly by displacement of a
 cover plate in the form of the slide lock member that secures the interior
 chamber against the entry of dirt and debris.
 The slide lock fastener of the invention can also be utilized in female
 assemblies where the aperture collar 45 extends from the exterior surface
 of housing 42 into the central annulus formed by torroidal magnetic 50. As
 will be illustrated by the examples of the embodiments which follow, the
 aperture collar 45 is modified to provide a channel for the passage of the
 cam follower surface as it moves through the region defined by the
 exterior aperture 44 and the depending aperture collar.
 One such example is illustrated by FIGS. 57-60 where it will be seen that
 aperture collar 45 depends from housing 42 and extends in spaced-apart
 relation adjacent the interior angular surface of magnet 50. In a
 preferred embodiment, the open end of collar 45 is also spaced apart from
 base 48 and female mounting cap 52. With reference to FIG. 57, it will be
 seen that body 61 of slide lock member 60 has a width "W" that is less
 than the interior diameter of collar 45. In order to permit the passage of
 body 61, the collar 45 is provided with a pair of opposing channels 46
 that are formed as chords at opposing positions in the cylindrical side
 wall of the collar. In a preferred embodiment, the dimensions of the
 channels 46, relative to the cross-sectional dimensions of slide body 61,
 are such that the slide member can move without binding and is restrained
 to minimize movement in other directions. Thus, in this embodiment, the
 opposing channels 46 also function as a guide for the slide lock member.
 In one method of construction and assembly, the ferromagnetic contact 66
 is secured in position after the slide body has been passed through the
 channels in collar 45. As will also be understood from FIG. 57, the
 configuration of the leading end 28 of the projecting male member 25 has
 been modified to pass through the slide lock aperture 68 as cam surface 30
 contacts and advances against cam follower surface 67 to move the slide
 body away from its starting position (I) and eventually into the engaged
 locked position (II) as shown in FIGS. 59 and 60. As will be understood
 from FIG. 58, the lock is disengaged by a manual pressure applied to
 release 70 while simultaneously withdrawing the male assembly 20 from the
 proximity of female assembly 40.
 One example of another alternative preferred embodiment of the invention
 for use with an aperture collar that extends into the annulus formed by
 torroidal magnet 50 is illustrated in FIGS. 61-64. In this embodiment, the
 body 61 is provided with a slide lock aperture 68 that is large enough to
 receive at least a portion of housing collar 45, i.e., the slide lock
 surrounds the collar. As best shown in FIG. 61, collar 45 is formed with a
 channel 46 by eliminating an arcuate segment of the collar to receive at
 least a projecting cam tab 610 that extends from the periphery of slide
 body aperture 68. The size of the channel 46, formed by the removal of a
 section of the sidewall of collar 45, is determined by the size and
 configuration of cam tab 610. In a preferred embodiment, the tab 610
 extends across the width of aperture 44 in housing 42.
 With reference to FIGS. 62 and 63 it will be seen that the cam tab 610 is
 provided with an offset section 612 that displaces the cam follower
 surface at the end of tab 610 from the plane of slide body 61. This offset
 has the effect of reducing the depth of penetration of male member 25
 required for the engagement of lock means 32 with tab 610. This, in turn,
 allows the depth or thickness of the female assembly to be reduced. It
 will be understood that this configuration can be modified so that tab 610
 is co-planar with slide body 61, or offset in the opposite direction to
 thereby increase the depth of penetration of the leading end of the male
 into the female assembly. Such changes are well within the skill of the
 art of workers in the field of magnetic fasteners and can be based upon
 the size, materials of construction and the configuration of the permanent
 magnets employed, as well as the materials of construction the elements
 comprising of both the male and female assemblies.
 As will be understood from FIG. 62, the male and female assemblies are
 unlocked, as in other of the embodiments described above, by applying a
 manual pressure to release 70 to move cam tab 610 from engagement with
 lock means 32 and thereafter separating the male and female assemblies.
 It will be appreciated from the above exemplary embodiments that other
 modifications to produce a locking magnetic fastener in accordance with
 the invention can be made to incorporate structural features and methods
 of operation that are described elsewhere in this specification, and that
 are known from the literature arid devices of the prior art.
 Exemplary of such modifications include extending the length of the collar
 45 of the embodiment of FIGS. 1-4 (either with or without the collar
 flange 47), in the direction of the magnet 50 so that the collar can be
 provided with channels 46 to receive the slide lock member. In this
 alternative embodiment (not shown), the collar does not extend into the
 magnet's annulus, and the slide lock member is held in slidable relation
 by the collar between the magnet and the housing 42.
 The slide lock fastener of the invention can also be utilized in female
 assemblies where the aperture collar 45 extends from the exterior surface
 of housing 42 into the central annulus formed by torroidal magnetic 50. As
 will be illustrated by the examples of the embodiments which follow, the
 aperture collar 45 is modified to provide a channel for the passage of the
 cam follower surface as it moves through the region defined by the
 exterior aperture 44 and the depending aperture collar.
 One such example is illustrated by FIGS. 57-60 where it will be seen that
 aperture collar 45 depends from housing 42 and extends in spaced-apart
 relation adjacent the interior angular surface of magnet 50. In an
 illustrative embodiment, the open end of collar 45 is also spaced apart
 from base 48 and female mounting cap 52. With reference to FIG. 57, it
 will be seen that body 61 of slide lock member 60 has a width "W" that is
 less than the interior diameter of collar 45. To permit the passage of
 body 61, the collar 45 is provided with a pair of opposing channels 46
 that are formed as chords at opposing positions in the cylindrical side
 wall of the collar. In a preferred embodiment, the dimensions of the
 channels 46 relative to the cross-sectional dimensions of slide body 61
 are such that the slide member can move without binding and is restrained
 to minimize movement in other directions. Thus, in this embodiment, the
 opposing channels 46 also function as a guide for the slide lock member.
 In one method of construction and assembly, the ferromagnetic contact 66
 is secured in position after the slide body has been passed through the
 channels in collar 45. As will also be understood from FIG. 57, the
 configuration of the leading end 28 of the projecting male member 25 has
 been modified to pass through the slide lock aperture 68 as cam surface 30
 contacts and advances against cam follower surface 67 to move the slide
 body away from its starting position (I) and eventually into the engaged
 locked position (II) as shown in FIGS. 59 and 60. As will be understood
 from FIG. 58, the lock is disengaged by a manual pressure applied to
 release 70 while simultaneously withdrawing the male assembly 20 from the
 proximity of female assembly 40.
 One example of another embodiment of the invention, for use with an
 aperture collar that extends into the annulus formed by torroidal magnet
 50, is illustrated in FIGS. 61-64. In this embodiment, the body 61 is
 provided with a slide lock aperture 68 that is large enough to receive at
 least a portion of housing collar 45, i.e., the slide lock surrounds the
 collar. As best shown in FIG. 61, collar 45 is formed with a channel 46 by
 eliminating an arcuate segment of the collar to receive a projecting cam
 tab 610 that extends from the periphery of slide body aperture 68. With
 reference to FIGS. 62 and 63 it will be seen that in a preferred
 embodiment, the cam tab 610 is provided with a offset Section 612 that
 displaces the cam follower surface at the end of tab 610 from the plane of
 slide body 61. This offset has the effect of reducing the depth of
 penetration of male member 25 required for the engagement of lock means 32
 with tab 610. This, in turn, allows the depth or thickness of the female
 assembly to be reduced. It will be understood that while preferred, this
 configuration can be modified so that tab 610 is co-planar with slide body
 61, or offset in the opposite direction to thereby increase the depth of
 penetration of the leading end of the male into the female assembly. Such
 changes are well within the skill of the art of workers in the field of
 magnetic fasteners and can be based upon the size, materials of
 construction and the configuration of the permanent magnets employed, as
 well as the materials of construction the elements comprising of both the
 male and female assemblies.
 As will be understood from FIG. 62, the male and female assemblies are
 unlocked, as in other of the embodiments described above, by applying a
 manual pressure to release 70 to move cam tab 610 from engagement with
 lock means 32 and thereafter separating the male and female assemblies.
 It will be appreciated from the above exemplary embodiments that other
 modifications can be made to incorporate structural features and methods
 of operation that are described elsewhere in this specification and that
 are known from the literature and devices of the prior art to produce a
 locking magnetic fastener in accordance with the invention. For example,
 the male asssembly can be modified by constructing the projecting male
 member 25 entirely from non-ferromagnetic materials so that there is no
 magnetic attraction and holding force exerted by the magnet 50. Although
 deemed to be a less preferred embodiment, such a construction is
 comprehended within the scope of the invention.
 As will be apparent from the following description of a further embodiment,
 the invention comprehends the use of electromagnetic devices to create the
 magnetic flux or field for practicing this invention. An exemplary
 construction embodying an electromagnetic device is shematically
 illustrated in FIG. 65 where common elements are identified by the numbers
 employed above. In the embodiment of FIG. 65, an annular electromagnetic
 device 200 is energized by a current transmitted through conductor leads
 202 to thereby create a magnetic attraction similar to that employed in
 previous embodiments. A contact switch 210 comprising contact elements 212
 and electrical leads 214 is positioned proximate the coil 200 and
 positioned to make contact with the forward end 28 of projecting male
 assembly 25 after engagement of the locking means. Slide lock member 260
 is provide with a cam follower surface 267 that is formed with a
 projecting lip in this embodiment. At the distal end of slide lock member
 260, a shoulder 268 is formed to receive and retain one end of biasing
 member 280, which in this embodiment is shown as a coil spring in
 compression. The opposite end of biasing member 280 is retained by the
 interior side wall of the housing 42.
 In the method of operation of the locking magnetic fastener of this
 embodiment, electrical energy is supplied to the electromagnetic coil 200
 when the male and female members are disengaged. As the projecting male
 member is passed through the exterior aperture in housing 42, it engages
 the cam follower surface 267, causing slide lock member 260 to move from
 its first position (I) to a second position (II) against the biasing force
 provided by spring 280. When the cam follower surface reaches lock means
 32, the slide lock member 260 is able to return to its first position (I),
 thereby securing the male and female assemblies in mated, locked relation.
 However, the magnetic attractive force is sufficient to draw the
 projecting male assembly 25 closer to coil 200 after locking engagement
 has occurred and until forward end 28 males contact with switch elements
 212, thereby turning off the flow of electrical current to electromagnetic
 coil 200. This mode of operation and assembly provides an energy-efficient
 device by deactivating the coil when the lock is securely engaged. The
 male and female assemblies are released by manually applying a force to
 the proximal end of slide lock member 260 to compress biasing spring 280
 and align the lock member aperture 268 with the exterior aperture of
 housing 42, thereby allowing the male assembly to be disengaged and
 withdrawn from the female assembly.
 As will be apparent to one of ordinary skill in the art, when the power to
 the electromagnetic coil or other device is turned off, there will be no
 magnetic force to attract the male member into a locked engaged position
 with the female member. This aspect of the invention can serve as a safety
 feature.
 Alternatively, the switch contacts 212 can be positioned on the exterior of
 the housing 42 adjacent aperture 44 to cause power to activate the coil
 for a predetermined period of time when the forward end 28 of the male
 member is proximate the aperture. In either embodiment, the coil is
 deactivated after the slide lock member has engaged the lock means.
 As will be apparent from the description of the embodiments of the
 invention utilizing one or more permanent magnets, the configuration of
 the slide lock member and its associated elements can be varied within the
 skill of the relevant art. Likewise, the specific electrical circuit of
 FIG. 65 provides but one of many practical configurations falling with the
 scope of the invention disclosed.
 It should be apparent from the foregoing that the locking magnetic fastener
 of the present invention is readily adaptable to various types and forms
 of fasteners other than those illustrated in the present drawings. Various
 modifications and adaptations of the forms of the invention here shown and
 described can also be made to meet particular requirements. Accordingly,
 the foregoing examples and illustrations ire not to be interpreted as
 restrictive of the invention, the scope of which is to be determined by
 reference to the following claims.