Abstract:
The invention resides in a latch comprising a lock including a locking pin mounted within a lock body, the locking pin movable between an extended position and a retracted position, the locking pin biased toward the retracted position; and a catch including a release mechanism, the release mechanism for holding the locking pin in the extended position; wherein a magnetic force between the locking pin and the release mechanism holds the locking pin in the extended position which causes the locking pin to engaged the catch.

Description:
FIELD OF THE INVENTION 
     This invention relates to a latch. In particular, the latch is used to prevent unwanted opening of a pool gate and therefore will be described in this context. However, it should be appreciated that the latch may be used on types of openings, such as doors and windows. 
     BACKGROUND OF THE INVENTION 
     Many home owners install pools in their backyard, especially home owners located in warmer climates. An inherent danger associated with backyard pools is child drowning. Accordingly, many governments throughout the world have legislated that backyard pools must be fenced. This has prevented a large number of child drownings. 
     Though pool fencing has reduced the number of child drownings, pool fencing has not eliminated child drownings entirely. This is mainly due to children accessing the pool through a pool gate. Pool gate latches have been developed in order to prevent unwanted access to the pool by children. Pool gates latches typically are located out of reach of children. 
     A very popular and commercially successful pool gate latch is shown in FIG. 2 of U.S. Pat. No. 5,362,116. The pool gate latch operates using a locking pin which is movable between an extended position in which the locking pin engages a catch and a retracted position in which the locking pin is withdrawn from the catch. A magnet forms part of the catch so that when the locking pin is in alignment with the catch, the magnet pulls the locking pin into the catch and hence to the extended position. The magnet ensures that every time the pool gate is closed the locking pin engages the catch. 
     The latch is typically placed on the inside of a pool gate so that only a person of sufficient height is able to move the locking pin to a retracted position from outside the pool gate, thus allowing the pool gate to be opened. Unfortunately, children are highly adaptable and understand they need to they need to artificially increase their height to enable them to open the latch. Accordingly, children often climb on to the pool gate so they are able to reach over the pool gate to gain access to the locking pin enabling them to open the latch. This can lead to a child drowning. 
     OBJECT OF THE INVENTION 
     It is an object of the invention to overcome and/or alleviate one or more of the above disadvantages or provide the consumer with a useful and/or commercial choice. 
     SUMMARY OF THE INVENTION 
     In one form, although not necessary the only or broadest form, the invention resides in a latch comprising: 
     a lock including a locking pin mounted within a lock body, the locking pin movable between an extended position and a retracted position, the locking pin biased toward the retracted position; and 
     a catch including a release mechanism, the release mechanism for holding the locking pin in the extended position; 
     wherein a magnetic force between the locking pin and the release mechanism holds the locking pin in the extended position which causes the locking pin to engaged the catch. 
     Normally, the locking pin is made from a magnetic material, such as steel. 
     The locking pin may be biased to the retracted position via a spring. The spring is typically a helical spring. 
     The release mechanism typically includes a magnet. The release mechanism may be operated so that the magnetic force changes to move the locking pin from the extended position to the retracted position. Usually the magnet is a permanent magnet. However, it is envisaged that the magnet may be an electro magnet. 
     The release mechanism may include an actuator that is able to move the release mechanism between a catch position and a release position. The release mechanism may be biased toward the catch position. The release mechanism may be biased toward the catch position via a spring. The spring is typically a helical spring. 
     A method of operating of a latch including the steps of: 
     locating a locking pin of a lock adjacent a catch having a release mechanism in a catch position so that the locking pin moves to an extended position to engage the catch via a magnetic force between the locking pin and the release mechanism. 
     The method may further including the step of: 
     releasing the locking pin of the lock from the catch by moving the release mechanism to a release position so that the magnetic force between the locking pin and the release mechanism is less than a biasing force applied to the locking pin to move the locking pin to a retracted position 
     The method may also include the step of: 
     moving the release mechanism to a catch position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention will be described with reference to the accompany drawings in which: 
         FIG. 1  is a perspective view of a latch according to an embodiment of the invention; 
         FIG. 2  is a transparent perspective view of a lock shown in  FIG. 1 ; 
         FIG. 3  is a transparent perspective view of a catch shown in  FIG. 1 ; 
         FIG. 4  is a transparent perspective view of a latch shown in  FIG. 1 ; 
         FIG. 5  is a further transparent perspective view of a latch shown in  FIG. 1 ; 
         FIG. 6  is a perspective view of the latch of  FIG. 1  with catch plate cover partially removed; 
         FIG. 7  is a perspective view of the catch of  FIG. 1  with catch plate cover partially removed; 
         FIG. 8  is a perspective view of a latch according to a further embodiment of the invention; and 
         FIG. 9  is a perspective view of a latch according to another further embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows a latch  10  for use on a pool fence gate. Specifically, the latch  10  shown is for use on a glass or polycarbonate pool fence gate. However, it should be appreciated that the latch may be used on a variety of pool fence gates. The latch  10  is made up of a lock  20  and a catch  50 . 
     The lock  20 , shown in more detail in  FIG. 2 , includes a lock body  30  having a lock aperture  31  which extends into the lock body  30 . A locking pin  32  is mounted within the lock aperture  31 . The locking pin  32  is movable between a retracted position in which the locking pin  32  is positioned within the lock aperture  31  and an extended position in which the locking pin  32  extends outwardly from the lock aperture  31 . A lock ring  33  is located adjacent the front of the lock aperture  31 . A hole  34  is located within the lock ring  33  to allow the locking pin  32  to pass through the lock ring  33 . A pin retainer  35  is located adjacent one end of the locking pin  32 . A lock helical spring  36  extends between and is connected to the pin retainer  35  and the lock ring  33 . Accordingly, the locking pin  32  is biased by the lock helical spring  36  toward the retraced position. 
     The lock  20  also includes a lock plate  40 , shown more clearly in  FIGS. 6 and 7 , which is used to attach the lock body  30  to pool gate panel. The lock plate  40  includes a lock attachment hole  41  through which is placed a locking screw  42 . A locking screw hole  37  is located within the lock body  30  to receive to the locking screw  42 . In use, a panel hole is drilled through the pool gate panel. The lock plate  40  and the lock body  30  are located on respective sides of the pool gate panel so that the panel hole is in alignment with the lock attachment hole  41  and the locking screw hole  37 . The locking screw  42  is placed through the lock attachment hole  41  and the panel hole and screwed into the locking screw hole  37 . The locking screw  42  is then tightened until the lock plate  40  and lock body  30  are held firmly on the pool gate panel. 
     The catch  50 , shown in detail in  FIG. 3 , includes a catch body  60  having a catch void  61  that extends within the catch body  60 . A catch cover  62  is located adjacent one end of the catch void  61 . A catch recess  63  is located on a front of the catch cover  62 . 
     A release mechanism  70  is located within the catch void  61  and includes a magnet  71 , a connection member  72  and a catch helical spring  73 . The magnet  71  is a permanent magnet and is connected to an end of the connection member  72 . The catch helical spring  73  is connected to the other end of the connection member  72  and to a spring mount  64  located at one end of the catch void  61 . The release mechanism  70  is movable between a release position in which the magnet  71  is moved toward the spring mount  64  and a catch position in which the magnet  71  is moved toward the catch recess  63 . The catch helical spring  73  biases the release mechanism  70  toward the catch recess  63 . 
     An actuator  80  is attached to connection member  72  in order to move the release mechanism  70  between the release position and the catch position. The actuator  80  includes a slide  81  and a handle  82 . An actuator channel  66  is located on the catch body  60  in which the slide is mounted. 
     The catch  50  also includes a catch plate  90  which is used to attach the catch body  60  to a pool fence panel and a catch plate cover  100  which is used to cover the catch plate  90 . The catch plate  90  and catch plate cover  100  are shown in more detail in  FIGS. 6 and 7 . The catch plate  90  includes a catch attachment hole  91  through which is placed a catch screw  92 . A catch screw hole  65  is located within the catch body  60  to receive the catch screw  92 . Two catch plate channels  93  are located on each side of the catch plate  90 . Two grub screw holes  94  are located adjacent respective ends of the two catch plate channels  93 . 
     The catch plate cover  100  includes a stop portion  110  and cover portion  120 . The stop portion  110  is used to stop the lock  20  and includes two pads  111 . The cover portion  120  is used to cover the catch plate  90 . The cover portion  120  includes two rails  121  that extend along the length of the cover portion  120 . Two grub screw holes  122  are located adjacent the end of the cover portion  120 . 
     In use, a panel hole is drilled through the pool fence panel. The catch plate  90  and the catch body  60  are located on respective sides of the pool gate panel so that the panel hole is in alignment with the catch attachment hole  91  and the catch screw hole  65 . The catch screw  92  is placed through the catch attachment hole  91  and the panel hole and screwed into the catch screw hole  65 . The catch screw  92  is then tightened until the catch plate  90  and catch body  60  are held firmly on the pool fence panel. 
     Once the catch body  60  and catch plate  90  are fixed to the pool fence panel, the catch plate cover  100  is attached to the catch plate  90 . The catch plate cover  100  is attached to the catch plate  90  by aligning the two rails  121  of the cover portion  120  of the catch plate cover  100  with the plate channels  93  in the catch plate  90 . The two rails  121  slide into the respective plate channels  93  until the cover portion  120  entirely covers the cover plate  100 . Grubs screws (not shown) are then placed through the grub screw holes  94  and  122  to hold the catch plate cover  100  to the catch plate  90 . 
     In use, the lock  20  is typically mounted to a hinged pool gate whilst the catch  50  is mounted to a fixed pool fence. When the hinged pool gate is closed, this causes the lock  20  and the catch  50  to be located adjacent each other, as shown in  FIG. 4 . This causes the magnet  71 , located within the catch void  61 , to attract the locking pin  32  via magnetic force and cause the locking pin  32  to be moved to the extended position. The locking pin  32 , when in the extended position, moves into the catch recess  63  to prevent movement of the hinged pool gate with respect to the fixed pool fence. 
     In order to release the locking pin  32  from the catch recess  63  and hence be able to open the hinged pool gate, the actuator  80  is slid along the actuator channel  65  which causes release mechanism  70  to be moved to the release position, as shown in  FIG. 5 . At the release position, the magnetic force applied to the locking pin  32  by the magnet  71  is less than the spring force applied by the lock helical spring  36  to the locking pin  32  causing the locking pin  32  to be moved to the retracted position. The pool gate is thus able to be opened. 
     When the actuator  80  is released, the catch helical spring  73  of the release mechanism  70  causes the release mechanism  70  to be moved to the catch position. The lock helical spring  36  of the lock  20  holds the locking pin  32  in the retracted position until the locking pin  32  is again aligned with the magnet  71  of the catch  50  at which point the magnetic force of the magnet will be stronger than the spring force provided by the lock helical spring  36  and the locking pin  32  will again move to the extended position. 
     One of the advantages of the above latch  10  is that when any lateral force is applied to the latch  10  when the locking pin  32  is in the extended position and thereby engaging the catch recess  63 , is that the locking pin  32  is unable to move to the retracted position even when the release mechanism  70  is moved to the release position. That is, a small amount of lateral force keeps the locking pin  32  locked to the catch recess  63 . Hence, the pool gate will be unable to be opened when a lateral force is being applied to the latch  10 . This prevents the unwanted opening of a pool gate by a person who climbs on the gate, and thereby applies a lateral force to the pool gate, even though the actuator  80  is able to be slid and cause the release mechanism to move to the release position. This is due to no physical connection being required between the actuator  80  and the locking pin  32  as shown in prior art pool gate latches. 
     It should be appreciated that the manner in which the catch body  60  and the lock body  30  is attached to a pool fence and pool gate may be modified as shown in  FIGS. 8 and 9 . 
     It should be appreciated various other changes and modifications may be made to the embodiment described without departing from the spirit or scope of the invention.