Abstract:
A hook for hanging articles is capable of holding the weight of a typical garment or knapsack while permitting the release of heavier objects. The hook has a base with two spaced-apart outwardly extending brackets and an arm pivotally mounted to and between the brackets. The arm is pivotable between a load bearing and load releasing position. A first magnet is secured to the arm and a second magnet is secured to the base. The first magnet is magnetically connected to the second magnet to maintain the arm in the load bearing position. The magnetic connection is releasable to permit the arm to move towards the load releasing position when a load having a weight in excess of a predetermined weight is applied to the arm. The first magnet provides weight for returning the arm to the load bearing position after the load has been released. Such hooks are particularly useful in schools to reduce the possibility of children being hung from hooks.

Description:
CROSS-REFERENCE APPLICATIONS  
       [0001]     This application is a continuation-in-part of U.S. Ser. No. 10/958,347 filed Oct. 6, 2004, which is herein incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to hooks for hanging articles, for example garments. In particular, the present invention relates to collapsible safety hooks.  
       DESCRIPTION OF RELATED ART  
       [0003]     Hooks are used for a variety of applications including hanging garments and other articles. Typically the hook is affixed to an upstanding structure such as a wall or a post. In some settings, for example in schools, rigid hooks for hanging garments and the like pose a safety risk to children who, through misfortune or deliberate act, find themselves suspended from the hook. In such a case, it would be beneficial if the hook would release automatically thereby permitting the child to escape from the hook in an expeditious manner.  
         [0004]     There have been a number of proposals in the art for such “safety hooks”. For example, Canadian patent application 2,305,128 filed Apr. 17, 2000 discloses a child safe coat hook that comprises a stationary wall plate secured to a wall and a hook-like member pivotally connected horizontally to the lower extremity of the wall plate. The hook is held in the upright position by a spring-like protruding portion on the wall plate engaged within a corresponding depression on the hook-like member. When sufficient manual pressure is applied to the top of the hook-like member, the hook-like member releases from the spring-like protrusion and falls to a lowered position which permits an excessive load to slide off the hook-like member. This hook disadvantageously does not automatically return to the upright position but must be reset manually.  
         [0005]     U.S. Pat. No. 6,199,811 issued Mar. 13, 2001 discloses a deformable safety hook comprising a base portion mountable to a wall and an article supporting portion extending from the base portion. The hook is constructed from a material that has sufficient strength to support an article, but readily deforms under an excessive load without permanent damage and substantially recovers its original shape when unloaded. Hooks, such as this, made of readily deformable materials having shape memory disadvantageously lose their shape memory relatively quickly and are prone to sudden breaking due to material fatigue.  
         [0006]     Canadian patent application 2,349,784 filed Jun. 4, 2001 discloses a safety coat hook that will not support loads in excess of 20-25 pounds. The safety coat hook comprises a top steel plate having a hook mounted thereon, a bottom steel plate affixed to a wall, a steel pin holding the steel plates together in a pivotable manner and a loaded spring on the steel pin which keeps the coat hook in an upright position. When excessive weight is applied, the steel spring does not have sufficient torque to keep the hook upright, therefore, the hook begins to collapse and the overweight item slides off the hook. Once the overweight item is off the hook, the steel spring returns the hook to the normal upright position. This hook disadvantageously has a number of sharp edges and pinch points for catching soft articles such as garments. In addition, the loaded spring disadvantageously snaps the hook back vigorously into the upright position, thereby creating a safety hazard as the rapidly moving hook may cause injury to a person.  
         [0007]     Canadian application 2,360,701 filed Oct. 31, 2001 is directed to a safety hook that operates similarly to the one described in CA 2,349,784. The safety hook comprises a plate affixed to a wall, a steel pin pivotably mounted on the plate, a loaded spring on the steel pin and an arm member (the hook) mounted on the pivotable pin. The loaded spring keeps the arm member in an upright position. When excessive weight is applied to the arm member, the steel spring does not have sufficient torque to keep the arm upright, therefore, the arm begins to collapse and the overweight item slides off the arm. Once the overweight item is off the arm, the steel spring returns the arm to the normal upright position. This hook disadvantageously has a number of sharp edges and pinch points for catching soft articles such as garments, necessitating further engineering and parts to reduce this problem. In addition, the loaded spring disadvantageously snaps the arm back vigorously into the upright position, thereby creating a safety hazard as the rapidly moving arm may cause injury to a person. This hook disadvantageously is constructed from many different parts thereby adding significantly to the cost of production.  
       SUMMARY OF THE INVENTION  
       [0008]     According to an aspect of the invention, there is provided a hook comprising: a base; an arm pivotally mounted to the base; a releasable connecting means for releasably connecting the arm to the base to maintain the arm in a load bearing position, the releasable connecting means releasable to permit the arm to move towards a load releasing position when a load having a weight in excess of a predetermined weight is applied to the arm; and effort imparting means mounted to the arm for returning the arm to the load bearing position after the load has been released.  
         [0009]     According to another aspect of the invention, there is provided a hook comprising: a base; an arm having a first end and a second end, the arm pivotally mounted to the base at a pivot position between the first and second ends so that the arm has a load bearing section from the first end to the pivot position and an effort bearing section from the second end to the pivot position; a releasable connecting means for releasably connecting the effort bearing section to the base to maintain the arm in a load bearing position, the releasable connecting means releasable to permit the arm to move towards a load releasing position when a load having a weight in excess of a predetermined weight is applied to the load bearing section; and effort imparting means mounted to the effort bearing section for returning the arm to the load bearing position after the load has been released.  
         [0010]     According to yet another aspect of the invention, there is provided a hook comprising: a base having a back and a front and having two spaced-apart outwardly extending brackets; an arm having a first end and a second end, the arm pivotally mounted to and between the brackets at a pivot position between the first and second ends so that the arm has a load bearing section from the first end to the pivot position and an effort bearing section from the second end to the pivot position, the arm pivotable between a load bearing position and a load releasing position; a first magnet secured to the arm proximal the second end; a second magnet secured to the base; the first magnet magnetically connected to the second magnet to maintain the arm in the load bearing position, the magnetic connection releasable to permit the arm to move towards the load releasing position when a load having a weight in excess of a predetermined weight is applied to the load bearing section of the arm; and, the first magnet providing weight on the effort bearing section of the arm for returning the arm to the load bearing position after the load has been released.  
         [0011]     According to still yet another aspect of the invention, there is provided a hook comprising: a base having a back and a front, two spaced-apart outwardly extending brackets, and a guard housing between the spaced-apart brackets, the back of the base having an opening; an arm having a first end and a second end, the arm pivotally mounted to and between the brackets at a pivot position between the first and second ends so that the arm has a load bearing section from the first end to the pivot position and an effort bearing section from the second end to the pivot position, the arm pivotable between a load bearing position and a load releasing position; a first magnet secured in a pocket integrally formed with the arm at the second end; a second magnet secured to the base; the first magnet magnetically connected to the second magnet to maintain the arm in the load bearing position, the magnetic connection releasable to permit the arm to move towards the load releasing position when a load having a weight in excess of a predetermined weight is applied to the load bearing section of the arm; and, the first magnet providing weight on the effort bearing section of the arm for returning the arm to the load bearing position after the load has been released.  
         [0012]     Such hooks may be used in any setting. They are particularly useful in schools and like institutions to reduce the possibility of children being suspended from hooks. They also help reduce damage to walls from overloaded backpacks.  
         [0013]     The base is preferably adapted to be mounted to an upright structure, for example, a wall, a door or a post. Mounting the base to the upright structure may be accomplished by any suitable means, for example, by nailing, screwing, bolting, riveting, gluing, taping or some combination thereof. Screwing and bolting are preferred as these methods offer a strong but reversible connection to the upright structure. In applications where screwing or bolting is impossible or undesirable, two-sided tape and structural glue are excellent alternatives.  
         [0014]     The arm of the hook generally provides support for hanging articles, for example, garments, bags, and the like. The arm has a first end and a second end and is pivotally mounted to the base at a pivot position between the first and second ends so that the arm may pivot between a load bearing position and a load releasing position. Any suitable pivoting means may be used. For example, the arm may be mounted to a protrusion on the base by means of one or more pins. The pins may be straight pins, screws, etc. or a combination thereof. The pin may be pivotally mounted to the arm and/or base on or in a surface thereof, or may pass through one or more holes in the arm and/or base. Preferably, the arm is pivotally mounted to the base by means of a straight pin passing through aligned holes in the arm and in one or more, preferably two, outwardly extending protrusions of the base.  
         [0015]     In the load bearing position, the arm is angled so that an article cannot slip off the hook. In the load releasing position, the arm is angled so that a load on the hook is able to slip off the hook. When a load on the arm has a weight that exceeds a predetermined weight, the arm pivots from the load bearing position to the load releasing position thereby allowing the load to slip off the arm. The arm may be of any suitable profile, for example, straight or curved. The arm may be contoured to assist in supporting articles when the arm is in the load bearing position, and to assist in releasing a load when the arm is in the load releasing position. For example, the arm may have a generally U-shaped portion between the pivot position and the first end and the arm may be mounted to the base at a location and in such a fashion as to encourage the article to slide away from the base into the bottom of the U-shaped portion thereby encouraging consistent application of load at a localized portion of the arm. The arm and base, including any protruding portions, may be contoured in such a fashion as to reduce or eliminate pinch or catch points.  
         [0016]     The arm preferably has a load bearing section from the first end to the pivot position, and an effort bearing section from the second end to the pivot position. The load bearing section supports articles hanging from the hook. Mounted to the effort bearing section is an effort imparting means for returning the arm to the load bearing position from the load releasing position after the load has been released. The effort imparting means is preferably a weight attached above or below the effort bearing section and preferably adjacent the second end to maximize mechanical advantage. More preferably, the weight is attached below the effort bearing section. Preferably, the weight is pivotally attached to the effort bearing section, for example, by means of a thin wire or string from which the weight hangs or by means of one or more pins. The weight should be at least heavy enough to be able to return the unloaded arm from the load releasing position to the load bearing position.  
         [0017]     A releasable connecting means releasably connects the arm to the base to prevent the arm from pivoting on the base in order to maintain the arm in a load bearing position. When a load having a weight in excess of a predetermined weight is applied to the arm (i.e. the load bearing section), the releasable connecting means releases the arm from the base permitting the arm to pivot on the base to thereby move the arm towards the load releasing position. The predetermined weight is particular to the specific application for which the hook is used. In connection with hooks in schools, a predetermined weight of from about 5-25 pounds, preferably 5-15 pounds, more preferably 5-10 pounds, even more preferably about 10 pounds, is generally suitable since most garments do not exceed about 5 pounds in weight and most school-age children exceed about 25 pounds in weight. If the hook is also intended to hold the weight of a knapsack, then the predetermined weight is desirably below but close to 25 pounds.  
         [0018]     Any suitable releasable connecting means may be used, for example, magnetic means, latches, hook &amp; loop fabric, etc. Magnetic means are preferred as they involve fewer parts, they are less prone to performance failure and they offer a sharp transition between connecting and releasing. Any of a number of arrangements of the magnetic means may be employed. For example: a magnet may be mounted on the effort bearing section of the arm and a ferromagnetic element (e.g. a steel plate) mounted on the base to which the magnet connects by means of its magnetic field; a magnet may be mounted on the base and a ferromagnetic element mounted on the effort bearing section to which the magnet connects by means of its magnetic field; a first magnet may be mounted on the base and a second magnet mounted on the effort bearing section to which the first magnet is connected by means of the magnetic fields of the two magnets. Since magnets have weight, it is possible for the same magnet to be simultaneously part of both the releasable connecting means and the effort imparting means. Other possible arrangements will be immediately apparent to one skilled in the art.  
         [0019]     When the releasable connecting means comprises a magnet, and when the hook is to be mounted on to a ferromagnetic structure (e.g. steel doors, walls having metal studs, etc.), sometimes it may be necessary to take measures to reduce the effect that the ferromagnetic structure has on the operation of the hook. For example, magnetic shielding may be used, the distance between the magnet and the ferromagnetic structure may be increased, and/or the magnet may be mounted on the base with a ferromagnetic element mounted on the effort bearing section of the arm. Magnetic shielding may be placed between the magnet and ferromagnetic structure and may be separate from or incorporated into the base. Increasing the distance may be accomplished by, for example, making the base of the hook thicker. Mounting the magnet on the base while having a ferromagnetic element on the effort bearing section of the arm means that the magnet would not be on a movable part of the hook, therefore, movement of the arm would be less affected by the ferromagnetic structure. Additionally, selecting a magnet having a field strength that declines more dramatically with distance may be done. A combination of the above measures may be used. Such measures may not be needed if the ferromagnetic structure does not unduly affect the hook&#39;s operation.  
         [0020]     The strength of the magnet (or combined strengths of the magnets) should provide a connection that releases when a weight in excess of the predetermined weight is applied to the load bearing section of the arm. Preferably, magnetic field strength falls off sharply with distance to provide a sharp transition between connecting and releasing. While the type of magnet is not particularly restricted, rare earth super magnets, particularly neodymium super magnets (available, for example, from Gaussboys™), are preferred. Such super magnets have high strength and keep their strength well over time. The shape of the magnet is not particularly restricted. Blocks and disks are preferred.  
         [0021]     The various parts of the hook may be constructed from any suitably strong materials, for example plastics, metals, composites, combinations thereof, etc. When the releasable connecting means comprises a magnet, the various parts of the hook are constructed from non-ferromagnetic materials, for example plastics, non-magnetic metals (e.g. aluminum), composites and combinations thereof. Preferably, the base and arm are made of a rigid plastic, for example polycarbonate, polycarbonate hybrid, acrylic, ABS, etc. Polycarbonate hybrid (e.g. Xenoy™ from GE Plastics) is of particular note. The arm is preferably molded as one piece for structural strength. The base may be molded as one piece or assembled from several pieces. The various parts of the hook may also be constructed with contoured edges to reduce the possibility of damage to articles and of personal injury, and to reduce the possibility of snagging articles on the hook.  
         [0022]     In another aspect of the invention, a hook rack comprises a plurality of hooks of the present invention mounted on a single support means and the support means mounted on an upright structure, for example, a wall or a post. Such an arrangement facilitates installation of many hooks quickly and efficiently. Such an arrangement also provides the opportunity to conceal the base of each hook within the support means to reduce the possibility of theft.  
         [0023]     Further features of the invention will be described or will become apparent in the course of the following detailed description. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]     In order that the invention may be more clearly understood, a preferred embodiment thereof will now be described in detail by way of example, with reference to the accompanying drawings, in which:  
         [0025]      FIG. 1  is a perspective view of one embodiment of a hook of the present invention;  
         [0026]      FIG. 2  is a side view of the hook of  FIG. 1 ;  
         [0027]      FIG. 3  is a front view of the hook of  FIG. 1 ;  
         [0028]      FIG. 4  is a back view of the hook of  FIG. 1 ;  
         [0029]      FIG. 5  is a top view of the hook of  FIG. 1 ;  
         [0030]      FIG. 6  is a bottom view of the hook of  FIG. 1 ;  
         [0031]      FIG. 7   a  is a side sectional view of the hook of  FIG. 1  in a load bearing position;  
         [0032]      FIG. 7   b  is a side sectional view of the hook of  FIG. 1  in a load releasing position;  
         [0033]      FIGS. 8   a  and  8   b  are side sectional views of a second embodiment of a hook of the present invention in a load bearing position and a load releasing position, respectively;  
         [0034]      FIG. 9  is a perspective view of a third embodiment of a hook of the present invention;  
         [0035]      FIGS. 10   a  and  10   b  are side views of the hook of  FIG. 9  in a load bearing position and a load releasing position, respectively; and,  
         [0036]      FIGS. 11   a  and  11   b  are side sectional views of the hook of  FIG. 9  in a load bearing position and a load releasing position, respectively, taken through the middle of the hook. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0037]     Referring to  FIGS. 1-7 , a hook in accordance with one embodiment of the present invention comprises a base  10  having two outwardly extending spaced-apart brackets  11 ,  12 . The base is mountable to an upright surface such as a wall by means of screws through screw holes  91 ,  92  in the base. Safety screws may be used and the screw holes may be countersunk so that the heads of the screws do not protrude above the surface of the base. When the base is mounted on an upright surface, the brackets  11 ,  12  protrude horizontally. All edges of the base and brackets are contoured for smoothness.  
         [0038]     An arm  20 , having a first end  21  and a second end  22 , is disposed between and pivotally mounted to the brackets  11 ,  12  by means of a first pin  15  inserted through aligned apertures  13 ,  14  in the brackets and through a first hole in the arm. The first pin  15  is thus located at a pivot position between the first and second ends of the arm. As is most clearly seen in  FIGS. 7   a  and  7   b,  the arm can pivot about the first pin  15  between a load bearing position ( FIG. 7   a ) and a load releasing position ( FIG. 7   b ). The section of the arm between the first end  21  and the first pin  15  is a load bearing section and generally bears a load placed on the hook. The section of the arm between the second end  22  and the first pin  15  is an effort bearing section, which is described in more detail below.  
         [0039]     The arm  20  is generally U-shaped in the load bearing section forming a groove or valley  24 . As is best seen in  FIG. 7   a,  the arm between the valley  24  and the first pin  15  is substantially aligned with upper edges  16  of the brackets  11 ,  12  when the arm is in the load bearing position. Thus, when an article is placed on the hook it will slide down into the valley providing a load on the load bearing section substantially at the valley. Still referring to  FIG. 7   a,  when the arm is in the load bearing position, the arm between the valley  24  and the first end  21  generally extends upwardly and outwardly so that a load cannot slip out of the valley and off the hook. However, the length of the arm just before the first end  21  is smooth and rounded to assist in permitting a load to slip off the arm when the arm is in the load releasing position as shown in  FIG. 7   b.  In the load releasing position, the arm  20  generally extends downwardly and outwardly.  
         [0040]     The section of the arm  20  from the first pin  15  to the second end  22  is the effort bearing section. As is evident from  FIGS. 7   a  and  7   b,  the effort bearing section angles downwardly from the first pin to the second end when the arm is in the load bearing position ( FIG. 7   a ) and angles upwardly from the first pin to the second end when the arm is in the load releasing position ( FIG. 7   b ). Pivotally mounted to the effort bearing section of the arm adjacent the second end is a substantially block-like weight  30  having a mounting tab  31 . The weight  30  is pivotally mounted to the arm by means of a second pin  35  inserted through two aligned holes in the arm and through an aperture in the mounting tab  31 . The weight is able to pivot freely about the second pin. As can be best seen in  FIG. 5 , the second end of the arm is split into two spaced-apart fingers  27 ,  28  having holes between which the mounting tab  31  is disposed.  
         [0041]     Attached to the underside of the weight  30  is a block-like neodymium super magnet  40  having a strength of 12 pounds. The magnet is attached to the weight by means of structural epoxy. Both the weight and the magnet are disposed between the brackets  11 ,  12  and under the second end  22  of the arm  20 . Referring to  FIG. 7   a,  when the arm is in the load bearing position, the magnet  40  rests on and is magnetically connected to a steel plate  42  protruding perpendicularly from the base  10 . When a load having a weight in excess of about 10 pounds is placed on the load bearing section of the arm  20 , the magnet  40  releases from the steel plate  42  and the arm moves to the load releasing position as depicted in  FIG. 7   b.  When the arm is in the load releasing position, the magnet is suspended somewhat above the steel plate.  
         [0042]     When the arm  20  is in the load releasing position, the load slides off the arm. Once the load has been removed from the arm, the combined weight of the weight  30  and the magnet  40  under the influence of gravity (i.e. the effort) pulling down on the effort bearing section of the arm causes the arm to pivot about the first pin  15  thereby returning the arm to the load bearing position. Once the arm is back in the load bearing position, the magnet  40  once again rests on the steel plate  42  and magnetically re-connects to the steel plate thereby maintaining the arm in the load bearing position.  
         [0043]     Unlike in prior art spring-loaded hooks, in a hook of the present invention the force holding the arm to the base to maintain the arm in the load bearing position (e.g. the magnetic force) may be much greater than the force exerted on the arm to return the arm to the load bearing position from the load releasing position (e.g. the combined weight of the weight and magnet). In prior art spring-loaded hooks, the two forces are the same, therefore, the prior art hooks are prone to snapping back violently once the load is released, raising the possibility of injuring a person. In contrast, in a hook of the present invention, the return force may be much less than the maintaining force thereby reducing the possibility of injuring a person when the arm returns to the load bearing position.  
         [0044]     The steel plate  42  is supported on the base  10  in a sleeve  17  protruding outwardly from near the bottom of the base. The steel plate is inserted into, and may be removed from, the sleeve through a slot  18  in the back of the base. The sleeve is a molded part of the base and accepts the steel plate as the plate slides through the slot. The sleeve is closed at the front to prevent removal of the steel plate from the front. The sleeve may be open on the top except for a lip so that the magnet  40  can directly contact the steel plate  42  in the load bearing position. The lip would prevent the magnet from lifting the steel plate out of the sleeve when the arm moves to the load releasing position. Since the base is generally attached to an upright surface, it is generally necessary to detach the hook from the upright surface in order to insert and remove the steel plate. The sleeve is open on a portion of the top so that the magnet  40  can rest directly on the steel plate  42 .  
         [0045]     A guard wall  19  is mounted between the brackets  11 ,  12  so that the weight  30  and the magnet  40  are disposed between the guard wall  19  and the base  10 . The guard wall helps prevent access to the magnet and the weight thereby reducing the possibility of tampering. The guard wall also increases the aesthetic appeal of the hook. The guard wall also helps prevent the magnet and weight from swinging as the arm moves between the load and effort bearing positions (or vice versa) so that the magnet  40  remains aligned with the steel plate  42 . The guard wall  19  may be mounted to one or both of the brackets  11 ,  12 , mounted to the sleeve  17 , or mounted to one or both of the brackets and the sleeve. Preferably, the guard wall  19  is mounted to both of the brackets  11 ,  12  and to the sleeve  17  for better structural rigidity and for better protection against tampering.  
         [0046]     Referring to  FIGS. 8   a  and  8   b,  a hook in accordance with a second embodiment of the present invention is similar to the hook of  FIG. 1  and comprises a base  110  having two outwardly extending spaced-apart brackets (only one shown  112 ). An arm  120 , having a first end  121  and a second end  122 , is disposed between and pivotally mounted to the brackets by means of a first pin  115  inserted through aligned apertures in the brackets and through a first hole in the arm. The arm can pivot about the first pin  115  between a load bearing position ( FIG. 8   a ) and a load releasing position ( FIG. 8   b ). The section of the arm between the first end  121  and the first pin  115  is a load bearing section and generally bears a load placed on the hook. The section of the arm between the second end  122  and the first pin  115  is an effort bearing section.  
         [0047]     Pivotally mounted to the effort bearing section of the arm adjacent the second end is a substantially block-like ferromagnetic weight  130  having a mounting tab  131 . The weight  130  is pivotally mounted to the arm by means of a second pin  135  inserted through two aligned holes in the arm and through an aperture in the mounting tab  131 . The weight is able to pivot freely about the second pin.  
         [0048]     Attached to a support platform  117  protruding horizontally from the base  110  is a block-like neodymium super magnet  140  having a strength of 10 pounds. The magnet is attached to the platform by means of structural epoxy. Both the weight and the magnet are disposed between the brackets and under the second end of the arm. Referring to  FIG. 8   a,  when the arm is in the load bearing position, the weight  130  is magnetically connected to the magnet  140 . When a load having a weight in excess of about  10  pounds is placed on the load bearing section of the arm  120 , the weight  130  releases from the magnet  140  and the arm moves to the load releasing position as depicted in  FIG. 8   b.  When the arm is in the load releasing position, the weight is suspended somewhat above the magnet.  
         [0049]     When the arm  120  is in the load releasing position, the load slides off the arm. Once the load has been removed from the arm, the weight of the weight  130  under the influence of gravity (i.e. the effort) pulling down on the effort bearing section of the arm causes the arm to pivot about the first pin  115  thereby returning the arm to the load bearing position. Once the arm is back in the load bearing position, the weight  130  once again is magnetically connected to the magnet  140  thereby maintaining the arm in the load bearing position. A guard wall  119  is mounted between the brackets and attached to the platform  117  so that the weight  130  and the magnet  140  are disposed between the guard wall  119  and the base  110 .  
         [0050]     Referring to  FIGS. 9-11 , a hook in accordance with a third embodiment of the present invention comprises a base  210  having two outwardly extending spaced-apart brackets (only one shown at  211 ). The base is mountable to an upright surface such as a wall by means of screws through three screw holes  291 ,  292 ,  293  in the base. Safety screws may be used and the screw holes may be countersunk so that the heads of the screws do not protrude above the surface of the base. When the base is mounted on an upright surface, the brackets protrude horizontally. All edges of the base and brackets are contoured for smoothness.  
         [0051]     An arm  220 , having a first end  221  and a second end  222 , is disposed between and pivotally mounted to the brackets by means of a pin  215  inserted through aligned apertures in the brackets and through a hole in the arm. The pin  215  is thus located at a pivot position between the first and second ends of the arm. As is most clearly seen in  FIGS. 11   a  and  11   b,  the arm can pivot about the pin  215  between a load bearing position ( FIG. 11   a ) and a load releasing position ( FIG. 11   b ). The section of the arm between the first end  221  and the pin  215  is a load bearing section and generally bears a load placed on the hook. The section of the arm between the second end  222  and the pin  215  is an effort bearing section.  
         [0052]     The arm  220  is generally U-shaped in the load bearing section forming a groove or valley  224 . When an article is placed on the hook it will slide down into the valley providing a load on the load bearing section substantially at the valley. The tops of the brackets are angled down and toward the front of the base so that articles cannot be hung from the base. Instead, articles will slide forward and down into the valley. Still referring to  FIG. 11   a,  when the arm is in the load bearing position, the arm between the valley  224  and the first end  221  generally extends upwardly and outwardly so that a load cannot slip out of the valley and off the hook. However, the length of the arm just before the first end  221  is smooth and rounded to assist in permitting a load to slip off the arm when the arm is in the load releasing position as shown in  FIG. 11   b.  In the load releasing position, the arm  220  generally extends downwardly and outwardly.  
         [0053]     The section of the arm  220  from the pin  215  to the second end  222  is the effort bearing section. As is evident from  FIGS. 11   a  and  11   b,  the effort bearing section angles downwardly from the pin to the second end when the arm is in the load bearing position ( FIG. 11   a ) and angles upwardly from the pin to the second end when the arm is in the load releasing position ( FIG. 11   b ). Integrally formed with the arm  220  at the second end  222  is a pocket  223  for holding a first magnet  240 . The first magnet may be frictionally secured in the pocket or it may be secured in the pocket by structural adhesive. The material from which the arm  220  is formed may have the capacity to concentrate, direct and therefore increase the pull force of the first magnet  240  contained in the pocket  223 .  
         [0054]     Referring to  FIG. 11   a,  when the arm is in the load bearing position, the first magnet  240  rests on and is magnetically connected to a second magnet  242 . The second magnet is secured by structural epoxy to a second magnet support  217 . When a load having a weight in excess of about 23 pounds is placed on the load bearing section of the arm  220 , the first magnet  240  releases from the second magnet  242  and the arm moves to the load releasing position as depicted in  FIG. 11   b.  The second end  222  of the arm together with the first magnet  240  in its pocket  223  moves arcuately as the arm  220  moves to the load releasing position. In the load releasing position, the second end  222  of the arm and the pocket  223  abut the underside of guard housing  219  and the first magnet  240  is separated from the second magnet  242 .  
         [0055]     When the arm  220  is in the load releasing position, the load slides off the arm. Once the load has been removed from the arm, the weight of the second magnet  240  under the influence of gravity (i.e. the effort) pulling down on the effort bearing section of the arm causes the arm to pivot about the pin  215  thereby returning the arm to the load bearing position. Once the arm is back in the load bearing position, the fist magnet  240  once again rests on the second magnet  242  and magnetically re-connects to the second magnet maintaining the arm in the load bearing position.  
         [0056]     Guard housing  219  is an integral part of the base  210  and completely covers the front and top of the hook except for a slot through which the arm  220  protrudes. The guard housing helps prevent access to the inside of the hook from the front thereby reducing the possibility of tampering, even more so than in the previous embodiments described above. The guard housing further increases the aesthetic appeal of the hook. The guard housing  219  is located between the brackets. The second magnet support  217  is an integral part of the guard housing. In fact, the base is formed as one integral unit including the brackets (e.g.  211 ), guard housing  219  and second magnet support  217 . This provides better structural rigidity and better protection against tampering.  
         [0057]     In order to insert the arm  220  and the magnets  240 ,  242  into the hook, the back of the base  210  is hollowed out to provide an opening. When mounted to an upright surface, the opening is inaccessible. Therefore, the magnets and other inner workings of the hook are inaccessible when the hook is mounted.  
         [0058]     In comparison to previously described embodiments, the third embodiment described herein advantageously provides better protection against tampering, requires fewer parts, is aesthetically more pleasing and can better hold the weight of a typical knapsack as well as a typical garment.  
         [0059]     From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.  
         [0060]     It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of the claims.  
         [0061]     Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.