Abstract:
An extermination device for exterminating pests includes a holder, trigger mechanism and a resilient ring mounted on the holder. When a pest actuates the trigger mechanism, the ring is released from the holder onto the pest, thereby killing the pest in a humane manner. A cover may be provided to protect the trigger mechanism from dirt and animals larger than target pest size. A loading device having a tapering body adapted to allow a resilient ring to be expanded from the narrow end to the wide end of the tapering body, wherein the wide end includes a formation adapted to engage with a holder of an extermination device.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention relates to a method and apparatus for the extermination of pests, in particular rats, stoats and other vermin.  
       BACKGROUND OF THE INVENTION  
       [0002]     In a number of countries such as New Zealand, introduced species of animal have had a detrimental effect on the indigenous or native plant, bird, insect and other life.  
         [0003]     In an attempt to control and exterminate pests, whether introduced species or not, a large number of different traps and similar mechanisms have been designed to capture and/or kill pests. A difficulty with many such traps is that the trapped pest does not die humanely and this can be a particular concern. A typical trap which is inhumane is the type of trap generally known as a gin trap which has a set of jaws to clamp a part of the pest. Normally in gin traps a pest is held until it either dies naturally or alternatively is killed by a person attending the trap.  
         [0004]     An object of the present invention is to provide a lightweight versatile user friendly relatively inexpensive means for exterminating pests which at least offers a useful alternative choice.  
         [0005]     A further object of the invention is to provide a means for exterminating a pest which substantially eliminates the risk of killing wildlife which is intended to be saved or preserved by use of the means for extermination, or to at least provide the public with a useful choice.  
       SUMMARY OF THE INVENTION  
       [0006]     In a first aspect, the invention provides an extermination device, comprising a holder and a trigger mechanism, the holder being configured to hold an expanded resilient ring and the extermination device being configured to release the resilient ring, such that it contracts around a pest, when the trigger mechanism is actuated by the pest.  
         [0007]     In a second aspect, the invention provides a method of exterminating a pest, comprising the steps of: expanding a resilient ring; and releasing the resilient ring onto a pest when the resilient ring is located around the pest. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     Examples of the invention will now be described with reference to the accompanying drawings in which:  
         [0009]      FIG. 1  is a perspective view from the side of an extermination device according to the invention;  
         [0010]      FIG. 2  is a side view of the extermination device shown in  FIG. 1 ;  
         [0011]      FIG. 3  is an end view of the extermination device;  
         [0012]      FIG. 4  is a perspective view from the side of the extermination device;  
         [0013]      FIG. 5  is a plan view of the exterminator device;  
         [0014]      FIG. 6  is a vertical section through an example of an extermination device incorporating a reloading and/or resetting mechanism with a plurality of resilient rings;  
         [0015]      FIG. 7  is a perspective view of an example of an extermination device having an internal trigger mechanism;  
         [0016]      FIG. 8  is a plan view of the device of  FIG. 7 ;  
         [0017]      FIG. 9  is a front plan view of a further embodiment of an extermination device;  
         [0018]      FIG. 10  is a perspective view of the device of  FIG. 9 ;  
         [0019]      FIG. 11  is a rear plan view of the device of  FIG. 9 ;  
         [0020]      FIG. 12  is a side plan view of the device of  FIG. 9 , showing internal features;  
         [0021]      FIG. 13  shows the firing mechanism of the device of  FIG. 9 ;  
         [0022]      FIG. 14  shows the trigger mechanism of the device of  FIG. 9 ;  
         [0023]      FIG. 15  is a view similar to  FIG. 9 , showing the device after it has been triggered and has released the resilient ring;  
         [0024]      FIG. 16  is a view similar to  FIG. 12 , showing the device after it has been triggered and has released the resilient ring;  
         [0025]      FIG. 17  is a perspective view of a cover for use with the extermination device of  FIG. 9 ;  
         [0026]      FIG. 18  is a perspective view of the device of  FIG. 9  and the cover of  FIG. 17  in an assembled state; and  
         [0027]      FIG. 19  is a plan view of a loading device for use with the extermination device of  FIG. 9 . 
     
    
     DESCRIPTION OF THE INVENTION  
       [0028]     Examples of the invention will now be described with reference to the accompanying drawings. The first example in FIGS.  1  to  5  of the drawings show the actual size of an extermination device designed for rats or stoats. It is to be appreciated that for other animals the overall size and dimensions of the extermination device may be larger or smaller as needed to suit the size of the target pests.  
         [0029]     In  FIG. 1  is shown an extermination device including a holder  100  and a front cover  3 .  
         [0030]     The holder  100  is shown in more detail in FIGS.  2  to  4 . The holder  100  comprises a central section  1  and a cover  2 , and is tubular, with an internal bore  4 . The holder may be circular in cross-section as shown in the drawings, or may have another suitable cross-section. The diameter of the bore  4  is chosen to suit the target pest and the tube has an entrance or open mouth  5  at a first end where the pest enters. For small pests such as mice, rats and stoats the diameter is preferably in the range 25 to 40 mm. For larger pests such as polecats, possums and cats, the diameter is preferably in the range 60 to 100 mm.  
         [0031]     The second end of the holder  100  is formed by the cover  2 , creating a closed region in which food or an attractant is placed.  
         [0032]     The extermination device has a trigger operated by a trigger mechanism  6  shown in  FIG. 3 . To set the trigger mechanism, it is pushed backwards in a slot  25  and to the right (as shown in  FIG. 4 ), such that it sits in a notch  24  in the holder. When a pest enters the trap, the trigger mechanism  6  moves accurately (as shown by arrow  7  in  FIG. 3 ), so that it is released from the notch and is forced forwards by a spring  20  to release the resilient ring  8 . The resilient ring  8  is mounted relative to the mouth  5  of the extermination device in a release position, adjacent to the open mouth  5 , such that after it slides off the open mouth  5  it contracts around whatever is within the open mouth  5  of the holder  1   00 . Other trigger mechanisms may also be suitable.  
         [0033]     The resilient ring  8  may be formed of natural or synthetic rubber or a composite material. It could also be formed from metal in the form of a spring, or at least partly of rigid material with a biasing means tending to force sides of the ring together. While the resilient ring is preferably circular in shape, it could, for example, be formed from a rectangle of resilient material with a hole cut through it. Other configurations may also be suitable.  
         [0034]     The resilient ring  8  has a normal diameter that is significantly less than the diameter of the holder at the release position so that on release from the open mouth  5  it contracts to its normal size which is less than the size of the neck of the target pest.  
         [0035]     On activation of the trigger mechanism  6  by a pest whose head is within the mouth  5  the rubber or composite ring  8  traps whatever is in the mouth of the extermination device. Any animal or pest that activates the trip arm  6  therefore has immediately placed around its neck a resilient ring which will cut off the blood and air supply to the animal thereby killing it humanely.  
         [0036]     Since the ring  8  is not retained by the extermination means, the animal may still move away from the site of the extermination means, so that other pests will be able to actuate the trigger mechanism.  
         [0037]     As shown in  FIG. 1 , a front cover  3  can be provided and is designed to protect against accidental tripping of the trip arm. The front cover  3  has an opening  9  to allow a pest to access the opening  5 .  
         [0038]     The front cover  3  connects with the holder at surface  10  and is positioned so that the target animal can still reach and actuate the trigger mechanism.  
         [0039]     In the second example shown in  FIG. 6  the extermination device has similar parts to those incorporated in the first example referenced by the same numerals. In this case the exterminator device has an automatic loading mechanism. The loading mechanism includes a moveable shaft  11  with a ratchet mechanism  12  operated by the trigger mechanism  6 . Movement of the shaft  11  is under the bias of a spring  13 . The shaft  11  includes stops  14 . A hinged cover  15  is provided to enable access to the mechanism when it is being reloaded with more or additional rings  8 .  
         [0040]     In use when an animal pest tries to eat bait or attractant  16  it knocks the trigger mechanism  6 . A first ring is released from the release position, contracting around the pest&#39;s neck. The spring  13  will then push forward and the trigger mechanism will be reset on its next notch ready to be tripped again. The forward movement of the shaft  11  presents the next in the succession of rings  8  to the release position adjacent to the mouth  5  of the holder  100 .  
         [0041]      FIGS. 7 and 8  show a third example of an extermination device according to the invention. This example differs from the device described above in that the trigger mechanism is located within the holder. This protects the trigger mechanism from dirt, twigs and the like, which may prevent it from functioning correctly. The trigger functions in a manner similar to that described above.  
         [0042]     These figures also show the device with a base plate  21  for mounting the extermination device in a suitable position. The base plate  21  preferably includes holes  22 ,  23  to facilitate such mounting.  
         [0043]     A preferred embodiment of the invention is shown in FIGS.  9  to  19 .  FIG. 9  is a front plan view, and  FIG. 10  is a perspective view, of the extermination device  1 , showing the trigger mechanism  6 , firing hammer  30  and resilient ring  8 . With reference to  FIG. 13 , the firing hammer  30  includes a generally cylindrical section  32  and a protrusion  33 . The cylindrical section  32  slides on rod  35 , which is joined to the rear face of the device housing by a screw  36 , as shown in  FIG. 11 . A spring  34  is mounted on the rod  35 , to urge the firing hammer  30  along the rod  35  towards the resilient ring  8 .  
         [0044]     With reference to  FIG. 14 , the trigger mechanism  6  is formed integrally with a lug  31  and is attached to the device housing by a screw  37 .  
         [0045]     In the cocked position shown in  FIG. 12 , the firing hammer compresses the spring  34  and is held in position by the lug  31 , as best shown in  FIG. 9 . When a pest enters the trap, forcing the trigger mechanism  6  upwards, the trigger mechanism pivots around the screw  37 , such that the lug  31  no longer restricts movement of the firing hammer  30 . The firing hammer slides along the rod  35  towards the resilient ring  8 . The protrusion  33  forces the resilient ring  8  off the holder, onto the pest. The position of the extermination device in the fired position as shown in  FIGS. 15 and 16 .  
         [0046]      FIG. 17  shows a cover  42  for use with the extermination device of this embodiment. The cover  42  includes a base section  40  and a cylindrical section  41 . The base section  40  may include holes and/or slots for securing the extermination device to the ground, a tree etc. The device shown in FIGS.  9  to  16  is assembled with the cover  42 , as shown in  FIG. 18 .  FIG. 18  shows the device and cover in a partially assembled state. The device is pushed into the cover through the cylindrical section  41 . In a fully assembled state the device would rest against the end  43  of the cover. This arrangement protects the mechanism of the device from contamination by dirt etc and prevents animals of a size greater than the diameter of the cylindrical section  41  from activating the trap.  
         [0047]      FIG. 19  shows a loading device for use with the extermination device of FIGS.  9  to  16 . The loading device includes a generally conical section  50  and a coupling section  51 . In use, the device is set in the cocked position and the coupling section  51  is inserted into the device, such that the shoulder  52  sits flush with the open mouth  5  of the device. A resilient ring  8  can then be forced along the generally conical section  50  and into the release position on the extermination device. The loading device is then removed.  
         [0048]     The device may be placed in any position that a targeted pest can access. The device may be placed on the ground, in a tree or attached to a board or post, for example.  
         [0049]     While the present invention has been illustrated by the description of the embodiments thereof; and while the embodiments have been described in detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of the Applicant&#39;s general inventive concept.