Abstract:
A magnetic hanging device for use in combination with a magnetically attractive surface. The device includes: a magnetic hanger comprising a magnetic sheet and a magnetic-sheet reinforcement suspending layer having a rear side to which the magnetic sheet is fixed and a front side having a hanging member attached thereto; and a plurality of spaced apart ribs disposed on the front side of the hanger, at least one of the ribs being a single-piece non-segmented rib. The hanger is configured in proportion to Young&#39;s modulus of elasticity; the length of the ribs; the cube of the thickness of the reinforcement suspending layer; and indirectly proportional to the average distance between the ribs.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a Continuation-in-Part of U.S. application Ser. No. 13/763,939 entitled “Suspending Device” filed on Feb. 11, 2013, which is a Continuation-In-Part of International Patent Application No. PCT/IL2011/000,652, filed on Aug. 10, 2011, and claims priority from U.S. Provisional Patent Application No. 61/344,512, filed on Aug. 12, 2010, which applications are hereby incorporated by reference in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to devices for hanging pictures, shelves or the like and, more specifically, to a magnetic suspending device. 
       BACKGROUND OF THE INVENTION 
       [0003]    Flexible permanent magnetic materials are often supplied in the form of sheets or rolls and have been commercially available for many years. These materials are typically prepared by mixing a powdered ferrite material with a suitable polymeric or plastic binder into a uniform mixture. The polymeric materials are often elastomers, and the process is therefore typically accomplished through the use of sheet extrusion or calendering. The mixture is converted into strip or sheet form, providing a permanent stable product that is usually somewhat flexible, and that can readily be handled and made into elements of any desired shape by cutting and/or stamping. 
         [0004]    The magnetic material is permanently magnetized so that the resulting elements can act individually as permanent magnets, the magnetic field being of sufficient strength that they will adhere to a magnetically attracted material, such as an iron or steel sheet. Many magnetic materials and the resultant sheet materials are typically inherently dark in color and it is therefore usual to attach these magnets to a printable substrate such as paper or plastic by gluing. A decorative pattern and/or other information may be printed on that paper or plastic. A popular application of such materials is thin, flat magnets having on their outer surface a decorative pattern and/or promotional information, including advertisements in direct mailings, newspaper inserts, and so forth, box toppers, coupons, business cards, calendars, greeting cards, postcards, and so forth. 
         [0005]    A minimal force, Fmin, of attractive interaction between a magnetizable plate and a magnetic member is defined by the following expression: 
         [0000]        F min&gt; Fg·Kfr   (equation 1)
 
         [0006]    where Fg is a force applied to the magnetic member by the hanged object due to gravity; Kfr is a coefficient of friction between the magnetizable plate and the magnetic member. 
         [0007]    The force of magnetic attraction between two substantially flat bodies where one of them is a flat permanent magnet and another is a plate made of a magnetizable material depends on the following parameters: (a) magnetic moment per unit volume of the magnet; (b) magnet volume; (c) magnetization value of the magnetizable material; and (d) contact area between the magnet and magnetizable member. 
         [0008]    The force Fmin is proportional to each abovementioned parameters. 
         [0009]    It is believed that the technology relevant to the present invention is disclosed in: U.S. Pat. No. 3,987,567 (Fritts, 1976 Oct. 16): US 2003/106,913 (Kohno, 2003 Jun. 12); US 2008/087,785 (Roche, 2008 Apr. 7); and JP 2005/218,487 (Ogushi, 2010 Aug. 18), all of which are incorporated herein by reference. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention provides a device that allows for convenient fixing of a picture, shelf, television, guitar or the like, at least temporarily (i.e. removably) on a magnetic surface. 
         [0011]    In accordance with embodiments of one aspect of the present invention there is provided a magnetic hanging device for use in combination with a magnetically attractive surface. The device includes: a magnetic hanger comprising a magnetic sheet and a magnetic-sheet reinforcement suspending layer having a rear side to which the magnetic sheet is fixed and a front side having a hanging member attached thereto; and a plurality of substantially rigid spaced apart ribs disposed on the front side of the hanger, at least one of the ribs being a single-piece non-segmented rib. The hanger is configured in accordance with the following equation: 
         [0000]    
       
         
           
             
               E 
               · 
               L 
               · 
               
                 t 
                 3 
               
             
             
               D 
               2 
             
           
         
       
     
         [0000]    wherein E is Young&#39;s modulus of elasticity, in giga Pascals; L=the length of the ribs in centimeters; t=the thickness of the reinforcement suspending layer, in tenths of millimeters; and D=the average distance between the ribs, in centimeters; and, with the resulting numerical value of the equation is in the range of 1,800 to 60,000. 
         [0012]    In some embodiments, the resulting numerical value of the equation is in the range of 5,000 to 40,000. In some embodiments, the resulting numerical value of the equation is in the range of 16,000 to 32,000. 
         [0013]    In some embodiments, the device is configured for use with a non-flat magnetically attractive surface. 
         [0014]    In some embodiments, at least one of the ribs is formed by a longitudinal fold. In some embodiments, the ribs are spaced apart by a distance greater than the width of the ribs. In some embodiments, the hanger has top and bottom edges and the ribs extend to at least one of said edges. In some embodiments, the hanger has right and left side edges and the ribs are parallel to at least one of said edges. In some embodiments, the ribs are parallel to each other. In some embodiments, at least some of the ribs are not all parallel to each other. In some embodiments, the ribs are flared out with respect to each other. In some embodiments, the ribs are diagonally arranged a long a path with respect to the hanger. 
         [0015]    In some embodiments, at least one of the ribs has a cutout configured so that an object can be hung therefrom. In some embodiments, the device further includes one or more pull flaps. 
         [0016]    It is a particular feature of the present magnetic hanging device that it can relatively easily be removed/disengaged from a magnetized surface by an initial separation of a corner or edge of the device from the magnetized surface after which the device readily detaches from the surface. Without limitation to theory, it is believed that a combination of the material properties of the device, which may include: Young&#39;s modulus of elasticity; material thickness; rib length; and rib spacing. 
         [0017]    Again, without limitation to actual operation, the readily removable hanging device is, in some embodiments, configured so that it is removed in a “popping” manner once an appropriate portion of a corner or edge of the device is separated from the magnetically attractive surface, which is in contrast to a peeling type of removal. This “popping” is a result of the extremely lower force required once a corner or edge is disengaged. In this regard, removal of the device occurs upon a bending thereof rather than peeling. 
         [0018]    One advantage of the present device is the possibility of a significant increase in the load that can be carried or hung, yet with relative ease of removal of the device from the magnetically attractive surface. 
         [0019]    Another advantage is that use of the device in combination with a magnetically attractive surface, the location of the object to be hung/supported can be conveniently changed, and without any actions such as removing a nail or screw and re-nailing/re-screwing. 
         [0020]    Thus, the present invention provides a magnetic hanging device that is configured to hang/support objects, including relatively heavy objects, while being flexible in location and being relatively easy to separate from the magnetically attractive surface. Furthermore the hanging device does not require fasteners such as nails, screw bolts or hooks, which in some cases may only be good for one-time use and that may require locating a stud in a wall (which may limit the hanging location); does not require drilling and resultant noise and dust; and is without the worry of weakening of the connection over time, which often causes shelves or pictures to fall. Also, if one wishes to remove a shelf/picture, there is no fastener or hole remaining in the wall or surface. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the appended drawings in which: 
           [0022]      FIG. 1A  is a perspective view of a magnetically attractive surface attached to a surface of interest such as a wall; 
           [0023]      FIG. 1B  is a perspective view of an embodiment of a magnetic hanging device of the present invention, usable in combination with, for example, the magnetically attractive surface illustrated in  FIG. 1 ; 
           [0024]      FIG. 2A  is a perspective view of an embodiment of the magnetic hanging device attached to a magnetically attractive surface; 
           [0025]      FIG. 2B  is a perspective view of an embodiment of the magnetic hanging device illustrating an initial step of disengagement from the magnetically attractive surface; 
           [0026]      FIG. 3  is a perspective view of a magnetic hanging device of the device, including pull-flaps; 
           [0027]      FIGS. 4A and 4B  are respective perspective and cross-sectional views of the magnetically attractive surface underlain by a mesh; 
           [0028]      FIG. 5  is a perspective view of an embodiment of the magnetic hanging device with longitudinal folds; 
           [0029]      FIG. 6  is a perspective view of an embodiment of the magnetic hanging device including vertically arranged stiffening ribs; 
           [0030]      FIG. 7  is a perspective view of an embodiment of the magnetic hanging device with stiffening ribs in a flared arrangement; 
           [0031]      FIG. 8  is a front view of an embodiment of the magnetic hanging device with stiffening ribs arranged along a diagonal path; and 
           [0032]      FIG. 9  is a perspective view of another embodiment of the magnetic hanging device. 
       
    
    
       [0033]    The following detailed description of embodiments of the invention refers to the accompanying drawings referred to above. Dimensions of components and features shown in the figures are chosen for convenience or clarity of presentation and are not necessarily shown to scale. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0034]    The following detailed description of embodiments of the invention may refer to the accompanying drawings. Embodiments and/or limitations featured in the figures are chosen for convenience or clarity of presentation and are not meant to limit the scope of the invention. 
         [0035]    Illustrative embodiments of the invention are described below. In the interest of clarity, not all features/components of an actual implementation are necessarily described. 
         [0036]      FIG. 1A  shows a magnetically attractive surface  120  (e.g. including any or a combination of iron, nickel, cobalt or manganese) that is mechanically fixed to a surface of interest  150 , e.g. a room wall. Any surface including a curved surface situated at any angle relative to gravity direction is in the scope of the current invention. 
         [0037]      FIG. 1B  shows an embodiment of a somewhat flexible magnetic hanger  110  provided with a hanging element  140  configured so that a load such as an artwork piece, wall clock, book shelf, ledge, night stand and so on (not shown) can be hung therefrom or supported thereby. The magnetic hanger  110  includes a somewhat flexible permanent magnet, typically prepared by mixing a powdered ferrite, neodymium or NdFeB material with a suitable polymeric or plastic binder into a uniform mixture. The mixture is converted into sheet form by extrusion or calendering. 
         [0038]      FIG. 2A  shows magnetic hanger  110  placed on magnetically attractive surface  120  mechanically connected to the surface of interest  150 , which in some embodiments, constitute together the hanging device  100 . When placed adjacent to magnetically attractive surface  120 , the magnetic hanger  110  is magnetically fixed on the magnetizable surface  120  due to the force of magnetic attraction. As noted above, this force is proportional to a volume of the magnetic hanger  110  and the contact area. Thus, the carried load can be increased by means of sheet thickening and extension of the contact area. 
         [0039]      FIG. 2B  shows the magnetic hanger  110  at the initial step of disengagement from magnetically attractive surface  120 , wherein an edge  115  of the hanger  110  has been slightly disengaged from the surface  120 . Typically, due to properties of the hanger  110 , once this initial disengagement has been accomplished, the hanging device will readily disengage from the magnetically attractive surface  120 . The aforementioned properties, which may be one of or a combination of mechanical properties; device dimensions; and associated stiffening ribs including spacing, length, width and thickness of such ribs, will be discussed below. 
         [0040]      FIG. 3  shows an embodiment of hanging device  100  for permanently or temporarily suspending an object of interest. The magnetic hanger  110  includes pull flaps  160  that can be used to assist in pulling magnetic hanger  110  off of surface  120 . Non-magnetic flaps  160  may be used. A plate  185  is provided with mortise-like ribs  180 , which can be configured to provide a receiving portion for hanging element  140  and/or add strength to the hanging device; or even be configured so that an object can be directly hung therefrom. 
         [0041]      FIGS. 4A and 4B  show magnetically attractive surface  120  attached to the surface of interest  150  wherein magnetically attractive surface  120  is underlain by a mesh  170 , which may include a filler. In  FIG. 4B , mesh  170  is a filled mesh  170 , which is flush with the surface of interest  150 . 
         [0042]      FIG. 5  shows an embodiment of hanging device  100  wherein the flexible magnetic hanger  110  is provided with stiffening ribs  130  in the form of longitudinal folds, typically vertical, as shown, for additional strength in the direction parallel to the ribs, i.e. vertical in this case, which is typical. Rib  130  in the center, is illustrated with a hook/hanging mechanism constituted by an angled cut-out  190  at the top of a rib, from which an object of interest may be hung. It should be noted that, mutatis mutandis, the instant magnetic hanging device can be used to hang or support items such as book shelves and the like. In such case, the device may additionally or alternatively include a shelf supporting projection rather than a hook-like mechanism. 
         [0043]      FIG. 6  shows the magnetic hanger  110  wherein stiffening ribs  130  are solid ribs attached to the hanger, although the ribs could be integrally formed. Ribs  130  are parallel and spaced apart, and have a width W, which is narrower than the distance D between the ribs. The hanger  110  thus is reinforced to be considerably stiff and strong in the direction of ribs  130 , yet still has some flexibility in the direction perpendicular to, or substantially perpendicular to, the ribs. As such, the device can be disengaged from magnetically attractive surface  120  by pulling generally at the location and direction of arrow A 1 . 
         [0044]      FIG. 7  shows an embodiment of the device where ribs  130  are not parallel to each other, rather in a flaring pattern, and also do not extend the entire dimension of the hanger  110 . Ribs  130  flare out in a generally arc-like path  200 . Further, ribs  130  are exemplified as generally rod-shaped ribs. For the most part, ribs  130  have a width smaller than the space between them. 
         [0045]      FIG. 8  shows an embodiment of the device where ribs  130  are also not parallel to each other, do not extend the entire dimension of the hanger  110  and flare in two directions along a generally diagonal path  220 . As such, the device can be removed from generally any direction, however, if ribs  130  were to extend mostly or all the way to the edges of the hanger  110 , with the exemplary path  220  shown, the device would be designed to be pulled from either the lower right corner or upper left corner thereof, i.e. From a location generally most adjacent to one of the ends of path  220 . 
         [0046]    In some embodiments, ribs  130  can be in the form of elongated L-shaped brackets (not shown). 
         [0047]      FIG. 9  shows an embodiment where magnetic hanger  110  includes a magnetic sheet  230 , typically rather flexible; and a generally sturdy magnetic-sheet reinforcement suspending layer  240 , typically made of metal (e.g. steel, aluminum, etc.), a composite material or a sturdy plastic. Suspending layer  240  includes a hanging member such as hanging element  140 , rib cut-out  190 , a hook or any other appropriate member from which an object can be hung or by which an object can be supported. 
         [0048]    With reference still to  FIG. 9 , in some embodiments, it is a particular feature of the hanging device that hanger  110  has properties (is designed) in accordance with the following equation: 
         [0000]    
       
         
           
             
               E 
               · 
               L 
               · 
               
                 t 
                 3 
               
             
             
               D 
               2 
             
           
         
       
     
         [0049]    Wherein E is Young&#39;s modulus of elasticity, in giga Pascals; L=the length of the ribs  130  in centimeters; t=the thickness of the hanger  110 , (specifically the portion between the ribs  130 , i.e. not including the rib thickness), in tenths of millimeters; and D=the average distance between the ribs  130 , in centimeters. And, with the aforementioned units, the resulting numerical value of the equation is in the range of 1,800 to 60,000 and in some embodiments in the range 5,000 to 40,000 and in some embodiments within the range 16,000 to 32,000. 
         [0050]    It may be considered that for practical purposes, where the device is designed in a manner generally in accordance with  FIG. 9 , i.e. with a magnetic sheet  230  backed by a reinforcing sheet  240  (typically but not limited to metal or plastic, typically a stiff plastic), the strength of the magnetic sheet is typically negligible, relatively. 
         [0051]    It should be noted that ribs  130  are preferably and typically each configured as unitary single-piece elements, i.e. not as a series of elements arranged end to end to constitute the full length of the rib, rather each is a one-piece rib. It should be clear that if a rib were formed by a plurality of segments, that rib would not provide the same stiffening as a single-piece rib as any space between the segments would provide a possible bend point. 
         [0052]    It should be understood that the above description is merely exemplary and that there are various embodiments of the present invention that may be devised, mutatis mutandis, and that the features described in the above-described embodiments, and those not described herein, may be used separately or in any suitable combination; and the invention can be devised in accordance with embodiments not necessarily described above.