Patent Publication Number: US-8540292-B2

Title: Reversible magnetic door stop/latch

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. application Ser. No. 11/636,722 filed Dec. 11, 2006, which is a divisional of U.S. application Ser No. 10/620,804 filed Jul. 2, 2003, now abandoned, which is a divisional of U.S. application Ser. No. 10/308,109 filed Dec. 3, 2002 that issued as U.S. Pat. No. 6,588,811 on Jul. 8, 2003, the entire disclosure of which is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to magnetic door stops and latches. More particularly, this invention relates to a device that uses the attractive and repulsive characteristics of magnets or magnetized objects for purposes of (1) preventing doors and other similar closures from slamming against a wall, baseboard, door jamb or door frame, or minimizing the force of such slamming, and (2) holding doors or similar closures in a stationary open or closed position, such that the door can be moved from such stationary position by applying sufficient force to overcome the magnetic force. 
     2. Background Art 
     Magnets have been used in devices for holding doors in the closed position. For example, magnetic door latch devices have been previously developed and are commonly found in the doors of kitchen cabinets, refrigerators, freezers, media cabinets, storage containers and numerous other such closures. Magnets have also been used in connection with mechanical latches and locks, with magnetic (usually electromagnetic) force applied to move or actuate a mechanical latch or lock mechanism. 
     Other magnetic devices have been previously developed for holding doors open. For example, simple magnetic door catches, such as that disclosed in U.S. Pat. No. 4,505,502, are also well known. Such devices use permanent magnetic force to hold a door in the open position, but perform no other function. Magnetic door holding devices also have been previously used in connection with fire safety systems, in which fire doors are held open by magnetic contacts on both the door and a wall behind the door. In such devices, the magnetic force holding the door open is overcome by electromagnetic or other means, thus automatically allowing the fire doors to swing closed. 
     While the use of magnets in these applications is well known, magnetic forces are not addressed to the problem of stopping doors from slamming or banging when opened or closed violently. Therefore, there arises a need in the art for a magnetic door stop that uses the repulsive forces of the magnets to prevent a door from slamming into a wall or door frame. More specifically, there arises a need in the art for a magnetic door stop that uses both the repulsive and attractive forces of magnets, selectively at the option of the user, to either hold a door in the open position (using the attractive forces of the magnets) or prevent a door from slamming (using the repulsive forces of the magnets). 
     BRIEF SUMMARY OF THE INVENTION 
     To achieve the foregoing and other objects, and in accordance with the purposes of the present invention as embodied and broadly described herein, the present invention provides a magnetic apparatus that functions to prevent slamming of a door or other such closure or structure using the repulsive forces of a magnet. The present invention also provides such a device that can be selectively set by the user so that in one position the device secures a door or other such closure or structure in an opened or closed position (using the attractive forces of the magnets) and in another position the device acts to prevent a door or other closure or structure from slamming (using the repulsive forces of the magnets). 
     In accordance with one aspect of the present invention, one magnet is mounted on or within a door and one magnet is mounted on or within a structure opposing the door, such as a baseboard, wall, or doorframe. The like poles of the magnets are adjacent to one another and thus repel one another. This may be accomplished in many possible configurations, including with the magnets aligned so that they make contact with one another upon the exertion of sufficient force, or with the magnets not actually making contact with one another but rather reaching sufficient proximity for the repulsive force to act in controlling or arresting the motion of the door. 
     In further accordance with the present invention, one of the two magnets may be mounted in a fashion that allows the magnet to be rotated, flipped or otherwise repositioned, such that in a one position, opposite magnetic poles of two magnets are adjacent to each other, and in a second position, like magnetic poles of the magnets are adjacent to each other. 
     The present invention has the advantages of providing an inexpensive, simple, and easy to operate mechanism that prevents noise and damage from slamming doors, but yet can be easily overridden by application of a moderate amount of manual force. The present invention also provides a simple means of selectively holding a door open or closed, but in a manner that allows the door to be manually moved. The simplicity of the present invention can be described as “binary,” in that the stop/latch has only two operational states—either the attractive state or the repulsive (non-attractive) state. All of these advantages are achieved without moving parts, or with a minimal number of moving parts, thus reducing the difficulties associated with installation, maintenance and use. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES 
       The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings. 
         FIG. 1  shows the magnetic door stop in the repulsive configuration to prevent a door from slamming into an opposing wall and baseboard. 
         FIG. 2  shows the magnetic door stop in the attractive configuration to hold the door in an open position. 
         FIG. 3  is a side view of the magnetic door stop mounted within a door. 
         FIG. 4  is a side view of the magnetic door stop mounted on an exterior surface of a door. 
         FIG. 5  is a side view of the magnetic door stop mounted within a baseboard. 
         FIG. 6  is a side view of the magnetic door stop mounted on an exterior surface of a baseboard. 
         FIG. 7  shows a magnet holding device to allow a user to selectively choose between the repulsive configuration or the attractive configuration. 
         FIG. 8  is an alternate embodiment of the magnet holding device shown in  FIG. 7 . 
         FIG. 9  is an alternate embodiment of the magnet holding device to allow a user to selectively choose between the repulsive configuration or the attractive configuration. 
         FIG. 10  is a side view of the magnet holding device shown in  FIG. 9 . 
         FIG. 11  is a top view of the magnet holding device shown in  FIG. 9 . 
         FIG. 12  is a front view of the magnet holding device shown in  FIG. 9 . 
         FIG. 13  is a cross-sectional view of the latching mechanism of the magnet holding device shown in  FIG. 9  in its normal resting position. 
         FIG. 14  is a cross-sectional view of the latching mechanism of the magnet holding device shown in  FIG. 9  in its compressed position. 
         FIG. 15  shows an alternate embodiment magnetic door latch mounted in a door and a doorframe. 
         FIG. 16  shows an enlarged view of magnetic door latch in  FIG. 15 . 
         FIG. 17  is a side view of the knob mounted recessed within a door. 
         FIG. 18  is a side view of the knob mounted flush onto a door. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A preferred embodiment of the present invention is now described with reference to the figures, where like reference numbers indicate identical or functionally similar elements. Also in the figures, the left most digit of each reference number corresponds to the figure in which the reference number is first used. While specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the relevant art will recognize that other configurations and arrangements can be used without departing from the spirit and scope of the invention. 
     Referring to  FIG. 1 , an embodiment of magnetic door stop  100  is shown. A first magnet  102  having a “positive” end  104  and a “negative” end  106  is mounted on an outside or exterior surface  108  of door  110 . For the purposes of this disclosure, the door has a height, width and depth or thickness, which defines a first side or surface, a second side or surface and a surrounding exterior edge. A second magnet  112  having a “positive” end  114  and a “negative” end  116  is mounted on an outside or exterior surface  118  of baseboard  120 . Second magnet  112  may be mounted on other structures opposing door  110  such as wall  122 . It should be noted that first magnet  102  may be mounted within the thickness of door  100  and that second magnet  112  may be mounted within the thickness of baseboard  120  or other structure. When door  110  is being opened and therefore moving towards wall  122 , magnetic door stop  100  may be in repulsive configuration  124  to prevent door  110  from slamming into wall  122 . Repulsive configuration  124  is accomplished when the like poles of first and second magnets are adjacent to one another and thus repel one another, i.e. “positive” end  104  of first magnet  102  will repel “positive” end  114  of second magnet  112  and “negative” end  106  of first magnet  102  will repel “negative” end  116  of second magnet  112 . This may be accomplished in many possible configurations, including with the magnets aligned so that they make contact with one another upon the exertion of sufficient force, or with the magnets not actually making contact with one another but rather reaching sufficient proximity for the repulsive force to act in controlling or arresting the motion of the door. Repulsive configuration  124  results in preventing door  110  from slamming against wall  122 . 
     As shown in  FIG. 2 , magnetic door stop  100  also can secure door  110  in an opened position by utilizing attractive configuration  226 . Attractive configuration  226  is accomplished when the opposite poles of first magnet  102  and second magnet  112  are adjacent to one another and thus attract one another, i.e. “positive” end  104  of first magnet  102  will attract “negative” end  116  of second magnet  112  and “negative” end  106  of first magnet  102  will attract “positive” end  114  of second magnet  112 . Attractive configuration  226  results in door  110  being held in an open position. 
     As shown in  FIG. 3 , first magnet  102  may alternatively be located within the thickness of door  110  such that an edge  301  of first magnet  102  is flush with exterior surface  108  of door  110 . Alternatively, first magnet  102  may be located on an exterior surface of door  110  such that another edge  403  of first magnet  102  is flush with exterior surface  108  of door  110  as shown in  FIG. 4 . The location of first magnet  102  and second magnet  112  is not limited to the bottom left corner of door  110  and the corresponding opposing position on baseboard  120 , as shown in  FIG. 1 . Instead, first magnet  102  may be located anywhere on exterior surface  108  of door  110  or within the door&#39;s thickness. Likewise, second magnet  112  may be located in the corresponding opposing position on or within the thickness of baseboard  120  or wall  122  such that when door  110  swings open, first magnet  102  and second magnet  112  are adjacent. Also, while magnet  102  is mounted on or within door  110  horizontally, it should be realized by those skilled in the art that magnet  102  may be mounted vertically relative to the door. 
     As shown in  FIG. 5 , second magnet  112  may be located within the thickness of baseboard  120  such that an edge  501  of second magnet  112  is flush with exterior surface  118  of baseboard  120 . Alternatively, second magnet  112  may be located on an exterior surface of baseboard  120  such that an edge  603  of second magnet  112  is flush with outside surface  118  of baseboard  120  as shown in  FIG. 6 . Like first magnet  102 , second magnet  112  may be mounted on or within baseboard  120  either vertically or horizontally. Further, while first magnet  102  is shown mounted on a door and second magnet  112  is shown located on a baseboard, it should be realized by those skilled in the art that first magnet  102  may be mounted on baseboard  120  and second magnet  112  may be mounted on door  110 . 
       FIG. 7  shows a magnet holder  728  that allows magnetic door stopper  100  to switch selectively between repulsive configuration  124  and attractive configuration  226 . Magnet holder  728  has a bottom  730  which can be mounted onto a door, baseboard, or wall with any appropriate holding mechanism or fastener such as a nail or screw. Two opposing sidewalls  732  and  734  project from bottom  730  of magnet holder  728 . When mounting magnet holder  728 , opposing sidewalls  732  and  734  should be parallel to the ground or floor. Inserted magnet  736  can be inserted into the magnet holder  728  and may be either first magnet  102  or second magnet  112 . If the user wants repulsive configuration  124 , inserted magnet  736  should be positioned so that the like poles of magnets  102 , 112  are adjacent to one another and thus repel one another. Alternatively, if the user wants attractive configuration  226 , inserted magnet  736  should be positioned so that the opposite poles of magnets  102 , 112  are adjacent to one another and thus attract one another. The user can selectively switch between the repulsive and attractive configurations by simply removing inserted magnet  736 , flipping or rotating it  180  degrees with respect to the poles, and then re-inserting magnet  736  into magnet holder  728 . 
       FIG. 8  shows an alternate embodiment of magnet holder  728 , which can also be mounted on a door, baseboard, wall or other structure. In  FIG. 8 , magnet holder  828  is elongated and has bottom  830  and opposing sidewalls  832  and  834 . Inserted magnet  836  can be inserted into the magnet holder  828  and may be either first magnet  102  or second magnet  112 . Inserted magnet  836  has two portions, “positive” portion  838  and “negative” portion  840 . Elongated magnet holder  828  has three portions, left portion  842 , mid-portion  844  and right portion  846 . The opposing magnet of magnet door stop will be lined up so that mid-portion  844  is adjacent to the magnet opposing inserted magnet  836 . For example, if magnet holder  828  is mounted on a baseboard, the mid-portion  844  will be adjacent to magnet  112  on door  110 . 
     If the user wants repulsive configuration  124 , inserted magnet  836  should be positioned so that the like poles of the magnets are adjacent to one another and thus repel one another. For example, if magnet  112  on door  110  is mounted such that the “positive” end  114  is exposed, inserted magnet  836  should be aligned so that “positive” portion  838  is located over mid-portion  844  of magnet holder  828 . Alternatively, if the user wants attractive configuration  226 , inserted magnet  836  should be positioned so that the opposite poles of the magnets are adjacent to one another and thus attract one another. For example, if magnet  112  on door  110  is mounted such that the “positive” end  114  is exposed, inserted magnet  836  should be aligned so that “negative” portion  840  is located over mid-portion  844  of magnet holder  828 . The user can switch between the repulsive and attractive configurations by simply shifting inserted magnet  836  so that the desired portion, either “positive” portion  838  or “negative” portion  840  is located over mid-portion  844  of magnet holder  828 . 
       FIGS. 9-14  show an alternate magnet holder  928  to allow a user to selectively choose between a repulsive configuration or an attractive configuration.  FIG. 9  shows first magnet  102  mounted onto door  110 . Magnet holder  928  is mounted onto wall  122  or baseboard  120 , and second magnet  112  is mounted therein. Magnet holder  928  includes a plate  948  which is mounted onto outside surface  118  of baseboard  120  with screws  950  and  952 . Two opposing sidewalls  954  and  956  extend from plate  948  and are spaced apart enough in order to allow second magnet  112  to be placed in between. Rod  958  is placed through sidewalls  954  and  956 . Second magnet  112  will contain a hole (not shown) through it. Second magnet  112  will be placed between sidewalls  954  and  956  with rod  958  extending through the hole of second magnet  112 . As shown in  FIG. 10 , second magnet  112  will freely rotate on rod  958  to enable user to select either positive end  114  or negative end  116  of second magnet  112  to face first magnet  102  mounted on door  110 . 
     Magnet holder  928  also includes a latch mechanism  960  which permits easy rotation of second magnet  112 , but also holds magnet  112  in place when user selects repulsive or attractive configuration of magnetic door stop. Shown in  FIGS. 9-14  is one possible latch mechanism comprising of a spring-loaded ball  962 . Spring-loaded ball  962  is attached to a spring  964 , which is located within channel  966  of plate  948 . Spring  964  attached to the bottom of channel  966 . Channel  966  is located within plate  948  and is of substantial size for spring loaded ball  962  to fit therein. Spring-loaded ball  962  snaps into depression  968  on the end of second magnet  112  to hold second magnet  112  in place. Depression  962  will be located on both positive end  114  of second magnet  112  and negative end  116  of second magnet  112  to enable user to select between repulsive or attractive configuration of magnetic door stop. 
       FIG. 13  shows latch mechanism  960  is its normal position, with spring  964  at rest. In its normal position, at least a portion of spring loaded ball  962  is located within channel  966  of plate  948 .  FIG. 14  shows latch mechanism  960  in its compressed position, with spring  964  compressed when spring loaded ball  962  snaps into depression  968  of second magnet  112 . In its compressed position, spring loaded ball is pushed further down into channel  964  of plate  948 . While magnet holder  928  is shown in the figures as being mounted on a baseboard or wall, it should be realized that magnet holder  928  could also be mounted on an exterior surface of a door. 
     First magnet  102  and second magnet  112  may be any appropriate magnetic material, including permanent magnets or electromagnets, and may vary in size. If magnetic door stop  100  is constructed with electromagnets, a user may select repulsive configuration  124  or attractive configuration  226  using a switch (not shown) that allows electric current to flow and consequently produces a magnetic field. In addition, magnetic door stop  100  may also be constructed by using a door of at least partially magnetic material instead of mounting first magnet  102  on door  110 . With a door of at least partially magnetic material, second magnet  112  may be oriented in an attractive or repulsive configuration relative to the magnetic door. 
       FIGS. 15-18  show alternate embodiment of magnetic door stop  100 . Referring to  FIGS. 15-16 , magnetic door latch  100   a  is shown. A first magnet  102   a  having a “positive” end  104   a  and a “negative” end  106   a  is mounted flush along an exterior edge and within the thickness of door  110   a . A second magnet  112   a  having a “positive” end  114   a  and a “negative” end  116   a  is mounted flush along an exterior edge and within the thickness of doorframe  120   a.    
     First magnet  102   a  and second magnet  112   a  may be in a repulsive configuration or a attractive configuration. Repulsive configuration is accomplished when the like poles of first and second magnets are adjacent to one another and thus repel one another, i.e. “positive” end  104   a  of first magnet  102   a  will repel “positive” end  114   a  of second magnet  112   a  and “negative” end  106   a  of first magnet  102   a  will repel “negative” end  116   a  of second magnet  112   a . Attractive configuration is accomplished when the opposite poles of first magnet  102   a  and second magnet  112   a  are adjacent to one another and thus attract one another, i.e. “positive” end  104   a  of first magnet  102   a  will attract “negative” end  116   a  of second magnet  112   a  and “negative” end  106   a  of first magnet  102   a  will attract “positive” end  114   a  of second magnet  112   a . Attractive configuration results in door  110   a  being held in a closed position with doorframe  120   a.    
       FIGS. 15-16  show a knob assembly  128   a  that allows magnetic door latch  100   a  to switch or rotate from an attractive configuration to a non-attractive or repulsive configuration. Knob assembly  128   a  contains knob  130   a , which is attached to first magnet  102   a  by a post P positioned perpendicular to a vertical plane in which first magnet  102   a  and second magnet  112   a  commonly lie ( FIGS. 17 and 18 . Knob assembly  128   a  also contains a suitable bearing or bushing B to permit easy rotation of first magnet  102   a ( FIGS. 16 ). The suitable bearing or bushing B also contains stopping means to align first magnet  102   a  with second magnet  112   a  of doorframe  120   a . Knob  130   a  is rotated by user, which consequently rotates first magnet  102   a  with respect to its poles to permit switch from an attractive configuration to a non-attractive or repulsive configuration. When switched to repulsive configuration, the magnets hinder the door&#39;s movement to the closed position, thus preventing or minimizing slamming. In addition, repulsive configuration may assist the user in opening door  110   a  if first and second magnets  102   a  and  112   a  are of substantial size. The size of first and second magnets  102   a  and  112   a  may vary depending on the needs of the user, i.e., a domestic user in a household doorway may only require a small magnetic latch  100   a  while a commercial user with a heavier door may require a larger magnetic latch  100   a.    
     As shown in  FIG. 17 , knob  130   a  may be mounted recessed into door  110   a . Alternatively, as in  FIG. 18 , knob  130   a  may be mounted flush onto exterior surface of door  110   a.    
     Alternately, second magnet  112   a  may be mounted within doorframe  120   a  such that the user may selectively switch second magnet  112   a  to be in a repulsive configuration with first magnet  102   a  or an attractive configuration with first magnet  102   a . Second magnet  112   a  may be mounted in a channel of doorframe  120   a  such that user may simply pull second magnet  112   a  out of the channel, flip it around to the desired “positive” end  114   a  or “negative” end  116   a , and insert back in the channel. 
     First magnet  102   a  and second magnet  112   a  may be any appropriate magnetic material, including permanent magnets or electromagnets, and may vary in size. If magnetic door latch  100   a  is constructed with electromagnets, a user may select repulsive configuration or attractive configuration using a switch (not shown) that allows electric current to flow and consequently produces a magnetic field. 
     It is envisioned that the magnet holder of the door stop of the present invention may be mounted on either the door or a structure opposing the door, and that the assembly for rotating one of the magnets of the door latch of the present invention may be mounted on either the door or a structure opposing the door. 
     While this invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.