Abstract:
A trap for exterminating moles has a support adapted for placement on the ground to support the trap in an upright position generally above the ground. An impingement device is operatively connected to the support for motion relative to the support for capturing the mole. A barrel mounted on the support in a generally vertical position is adapted for slidably receiving a portion of the impingement device in a retracted position. An explosion chamber receives an explosive force and directs the explosive force generally downward against the portion of the impingement device received in the barrel to drive the impingement device rapidly downward to an extended position. A trigger mechanism triggers an explosion producing the explosive force.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to mole traps and more particularly to a mole trap having an explosive force for actuating an impingement device. 
     Moles are very robust animals that can survive in rather adverse conditions. Frequently, moles dig tunnels through lawns, golf courses, and carefully-tended gardens in search of their main food source, worms. Moles are extremely efficient diggers that can excavate 12-15 feet of tunnel per hour. Moles use their powerful front paws to claw at dirt and pack it on all sides to create an underground tunnel. Moles push excavated dirt from their tunnels up to the ground surface. The excavated dirt creates piles on the ground surface that can get larger than 2 feet in diameter (although most are 6 to 9 inches in diameter). 
     Damage resulting from mole tunnels include bare spots created by the piles of excavated dirt as well as the corresponding loss of structural integrity of the soil. Mole tunnels can undermine concrete slabs, driveways, pools, and even shallow foundations. Extensive mole tunnel networks can cause severe damage to a lawn requiring expensive repairs that can include tilling and replanting of an entire lawn. 
     Existing methods for exterminating moles include mole traps that are placed above the ground and are actuated to thrust sharp objects into the mole tunnel to impale the mole. These existing traps are generally ineffective in that they have low success rates for catching moles even after a mole has actuated the device. Some existing traps rely on spring loaded impingement devices that do not generate adequate force to effectively and quickly penetrate the ground to impale the mole. Also, existing traps rely on impingement devices that penetrate an inadequate section of the mole tunnel so that moles that actuate the trap are able to escape the impingement device. 
     SUMMARY OF INVENTION 
     Among the several objects and features of the present invention may be noted the provision of a mole trap which effectively exterminates a mole; the provision of such a mole trap which penetrates the mole tunnel with sufficient force to impale the mole; the provision of such a mole trap which is triggered to generate an explosive force; the provisions of such of mole trap which can prevent escape of the mole; the provision of such a mole trap which is fast-acting; and the provision of such a mole trap which penetrates a large volume of a mole tunnel. 
     Generally, the mole trap of the present invention comprises a support adapted for placement on the ground to support the trap in an upright position generally above the ground. An impingement device for capturing the mole is operatively connected to the support for motion relative to the support. A barrel is mounted on the support generally in a vertical position and is adapted for slidably receiving a portion of the impingement device in a retracted position. The barrel defines an explosion chamber for receiving an explosive force and directing the explosive force generally downward. The explosive force is directed against the portion of the impingement device received in the barrel to drive the impingement device downward to an extended position. A trigger mechanism triggers an explosion producing the explosive force. 
     In another aspect of the present invention, the mole trap of the present invention generally comprises an impingement device including a thrust plate and sharpened pins depending from the thrust plate in the upright position of the trap. The pins are arranged in an array of at least two rows with each row including a multiplicity of pins. The trigger mechanism triggers rapid movement of the impingement device into the ground for impaling the mole on one or more of the pins. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective of a mole trap of the present invention. 
     FIG. 2 is a section of the mole trap taken along the plane indicated by line  2 — 2  of FIG.  1 . 
     FIG. 3 is a front elevation with a front wall of a housing removed to show sharpened pins of an impingement device of the mole trap. 
     FIG. 3A is a bottom view of the mole trap. 
     FIG. 4 is an enlarged fragmentary section showing a trigger mechanism and a top portion of a barrel of the mole trap. 
     FIG. 4A is an exploded view of FIG. 4 showing an explosive device removed from the barrel of the mole trap. 
     FIG. 5 is an enlarged fragmentary section showing the impingement device of the mole trap. 
     FIG. 6 is a section of the mole trap taken along the plane including line  6 — 6  of FIG.  2 . 
     FIG. 7 is a section of the mole trap showing the trigger mechanism in an actuated position. 
     FIG. 8 is a section of the mole trap showing a firing pin in a released position and in contact with the explosive device. 
     FIG. 8A is an enlarged fragmentary section of FIG. 8 showing the trigger mechanism and the top portion of the barrel of the mole trap. 
     FIG. 9 is a section of the mole trap showing the impingement device in a fully extended position. 
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, and in particular FIG. 1, a mole trap of the present invention is generally indicated at  1 . The mole trap  1  is used to exterminate moles by placing the trap on ground (i.e., lawns, golf course, gardens) where moles are expected to travel beneath the surface. The mole trap  1  is typically effective when placed over existing mole tunnels where moles are likely to frequent. As described in more detail below, the mole trap of the present invention provides effective extermination of moles tunneling below the trap. 
     As shown in FIGS. 1-3, the trap comprises a support in the form of a housing, generally indicated at  5 , comprising a top wall  7 , two opposed side walls  9 , a removable front wall  11  and a removable back wall  13  that together define an enclosed space  15 . It will be understood that the front wall  11  and back wall  13  could be integral (i.e., non-removable) with the top wall  7  and side walls  9  to form the housing  5 . The housing  5  allows the trap  1  to be placed on the ground in an upright position so that the side walls  9  straddle an existing mole tunnel passing below the trap generally from the front wall  11  to the back wall  13  of the housing. Placing the trap  1  in this manner increases the length and volume of the mole tunnel that can be penetrated by the trap resulting in a higher success rate of the trap. In the illustrated embodiment, the front wall  11  and back wall  13  have fastener holes  17  that are aligned with corresponding holes in the top wall  7  and side wall  9  so that threaded fasteners (not shown) may be used to secure the front and back walls to the trap  1 . By removing the fasteners from the fastener holes  17 , the front wall  11  and back wall  13  can be easily removed from the housing  5  to allow access to the enclosed space  15  for checking the positioning of the trap  1  or performing maintenance. It will be understood that other means for allowing access to enclosed space  15  can be provided such as providing a hinged connection on the front wall  11  or back wall  13  or mounting removable access doors on the housing  5 . Also, the trap  1  may have an indicator (not shown) mounted to the housing  5  to provide external monitoring of the positioning of the trap. An integral flange  21  extends laterally from the bottom of each side wall  9  to contact the ground and help stabilize and maintain the trap  1  in an upright position. Each flange  21  has two spaced apart attachment holes  23  for receiving a stake (not shown) that can be inserted into the ground to prevent the trap from sliding along the surface of the ground. A barrel  25  mounted to the top wall  7  of the housing  5  extends up from the housing in a generally vertical position. The barrel  25  has a tubular body  27  defining an explosion chamber  29  with the body having a lower end  31  extending through an opening in the top wall  7  of the housing  5  and a threaded upper end  35 . A mounting flange  41  is spaced above the lower end  31  of that barrel  25  to connect the barrel to the top wall  7  of the housing  5 . In the illustrated embodiment, the mounting flange  41  is welded to the barrel body  27  and secured to the top wall  7  of the housing  5  via threaded fasteners  43 , but it will be understood that other suitable forms of connection could be used (e.g., rivets). 
     As shown in FIGS. 2,  3 ,  3 A and  5 , the trap has an impingement device, generally indicated at  51 , at least partially housed in the enclosed space  15 . The impingement device includes a thrust plate  53  generally parallel with the top wall  7  of the housing  5  and a plurality of sharpened pins  57  depending from the thrust plate  53  for penetrating the ground and impaling the mole. A shaft  59  extends upward from the thrust plate  53  through the top wall  7  and is slidably received in the explosion chamber  29  of the barrel  25 . As shown in FIG. 3A, the pins  57  are arranged in an array of three rows with each row having six pins. Preferably, the pins  57  are approximately six inches in length and approximately {fraction (3/16)} inch in diameter, however, it will be understood that other sizes and shapes of pins are contemplated by this invention. Also, varying quantities of pins  57  can be used and the pins may have alternative arrangements including unequal spacing between the pins or a random, non-linear organization. However, a sufficient number and arrangement of pins  57  is required to produce an adequate impingement area of the trap  1  to improve the opportunity of striking the mole when the trap is tripped. 
     As shown in FIGS. 4 and 4A, an explosive device  71  is mounted on the upper end  35  of the barrel  25  and is housed in the explosion chamber  29 . In the illustrated embodiment, the explosive device  71  is in the form of a modified shotgun shell having a cylindrical shell body  75  containing gun powder and a cap  77  at the top of the body. The cap  77  has a larger diameter than the shell body  75 . The shell body  75  is sized to fit within explosion chamber  29  and the cap  77  is sized for engagement with the upper end  35  of the barrel  25  so that the explosive device is supported by the barrel body  27 . It will be understood that the explosive device  71  may comprise a modified 20-gauge shotgun shell, a 0.38 caliber blank cartridge or other types of explosive devices. Also, the explosive device  71  may be of other sizes and geometric shapes (e.g., polygonal). 
     In the illustrated embodiment, the mole trap  1  has a trigger mechanism, generally indicated at  85 , for triggering the explosive device  71 . As best shown in FIGS. 4 and 4A, the trigger mechanism  85  includes a breech  87  having a generally cylindrical body  89  with top wall  91 , a bottom wall  93 , a side wall  95  and a central axial bore  97  having a larger diameter lower section  99  for receiving the upper end  35  of the barrel  25  and the explosive device  71 . In the illustrated embodiment, the lower section  97  of the breech  87  has internal threads  101  for mating with the threaded upper end  35  of the barrel  25 . The top wall  91  and bottom wall  93  extend laterally past the side wall  95  of the breach  87  to form upper and lower guides,  105  and  107  respectively. The upper guide  105  has an opening  109  axially aligned with and spaced above an opening  111  in the lower guide  107 . A firing pin, generally designated  121 , is slidable in the axial bore  97  and has a truncated conical head  123 , an elongate body  125  extending upward from the base of the head through the top wall  91  of the breech  87  for connection to a handle  127  (FIG.  1 ), and a shoulder  129  spaced above the conical head and extending laterally from the elongate body. A spring  135  located in the axial bore  97  extends between the top wall  91  of the breech  87  and the shoulder  129  for driving the firing pin  121  rapidly downward. A sear  137  is hingedly attached to the breech  87  via a hinge pin  139  and is movable in a cavity  141  formed in the side wall  95  of the breech. The sear  137  has a lip  145  that protrudes into the central bore  97  of the breech  87  for engaging the shoulder  129  of the firing pin  121  and a lower foot  147  extending through the side wall  95  of the breech. 
     As shown in FIG. 4, a trigger  161  is slidably attached to the breech  87  by having an upper portion  163  slidably received in the opening  109  in the upper guide  105  and a lower portion  165  slidably received in the opening  111  in the lower guide  107 . In the illustrated embodiment, the trigger  161  is generally an elongate plate  169  having an intermediate stepped surface  171  for support against the lower guide  107 , a generally flat inner surface  175  for slidable engagement with the lower foot  147  of the sear  137 , a notch  179  below the flat inner surface and a flat lower end  183  that is supported by an actuator plate  187  spaced below the lower guide. The trigger  161  is slidable in a vertical direction in relation to the barrel body  27 . As shown in FIG. 2, parallel supports  191  connected to the actuator plate  187  extend down through the barrel mounting flange  41 , the top wall  7  of the housing  5  and the thrust plate  53 . A ground plate  195  for sensing movement of the ground is attached to the lower ends of the parallel supports  191  and is generally surrounded by the sharpened pins  57  of the impingement device  51 . The trigger  161 , actuator plate  187 , parallel supports  191 , and ground plate  195  are all operatively connected and are movable in relation to the housing  5  and barrel  25  so that any upward force received by the ground plate causes the actuator plate to move correspondingly upward to actuate the trigger mechanism  85 . As shown in FIGS. 8 and 8A, upward movement of the trigger  161  from the initial position shown in FIG. 4 causes the lower foot  147  of the sear  137  to disengage the inner surface  175  of the trigger so that the foot  147  is received in the notch  179  of the trigger  161  and the sear pivots outwardly. At the outwardly pivoted position, the lip  145  of the sear  137  is withdrawn from the central bore  97  of the breech  87  so that the firing pin  121  is thrust rapidly downward for contact with the explosive device  71 . 
     In use, the mole trap  1  of the present invention is placed on the ground so that the housing  5 , the sharpened pins  57 , and the ground plate  195  engage the surface of the ground. As shown in FIG. 2, the trap  1  is first set to a position where the ground plate  195  is substantially parallel to the tips of the sharpened pins  57  and the inner surface  175  of the trigger  161  rests against the bottom foot  147  of the sear  137  so that the lip  145  of the sear holds the firing pin  121  in a raised position against the thrust force of the spring  135 . As shown in FIG. 7, a mole tunnel creates a mound of raised earth  201  that protrudes upward from the otherwise flat ground surface  203 . As a mole moves beneath the trap  1 , the raised earth  201  contacts the ground plate  195  forcing the ground plate and actuator plate  187  (connected via parallel supports  191 ) to move upward. As shown in FIGS. 8 and 8A, the upward movement of the actuator plate  187  causes the trigger  161  to move upward so that the bottom foot  147  of the sear  137  slides along the inner surface  175  of the trigger  161  and into the notch  179  allowing the sear to pivot outward so that the lip  145  disengages the shoulder  129  of the firing pin  121 . After the sear  137  disengages the firing pin  121 , the pin is released and thrust downward by the driving force of the spring  135  so that the pin impacts the cap  77  of the explosive device  71  in the explosion chamber  29 . The impact of the firing pin  121  with the explosive device  71  creates an explosion which generates a downward force acting against the shaft  59  of the impingement device  51 . As shown in FIG. 9, the force acting on the shaft  59  thrusts the impingement device  51  rapidly downward such that the thrust plate  53  contacts the surface of the ground  203  and the sharpened pins  57  penetrate the ground to impale the mole that has tunneled beneath the trap  1  and actuated the trigger mechanism  85 . The downward force generated by the explosion and resulting thrust of the impingement device  51  occurs rapidly and forcefully so the mole has insufficient time to retreat in the tunnel and escape contact with the sharpened pins  57 . Also, the effectiveness of the trap is increased by the arrangement of the sharpened pins  57  which penetrate a long section of the mole tunnel thus reducing the chance that the mole would have enough space in the mole tunnel to avoid the sharpened pins. 
     When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
     In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. 
     As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.