Animal traps and trigger mechanisms

Abstract

An animal trap may include a source of compressed gas; a trigger mechanism configured to be actuated by an animal, and a kill mechanism powered by compressed gas. The trap may include two or more trigger valves connected in series. At least one trigger valve may include an opening, a valve seat surrounding the opening, a valve member having a sealing surface, and an O-ring arranged to seal between the sealing surface and the valve seat. One or more flow paths may allow gas to flow along at least part of an internal periphery of the O-ring. The trigger may include a trigger rod extending in a rest position from a mount at or near a first end thereof. The trigger rod may be mounted for pivoting movement about the mount, and may have two rotational degrees of freedom. Pivoting movement of the trigger rod in any direction away from the rest position may result in actuation of the trigger.

What is claimed is: 
     
         1 . A pneumatically powered animal trap including:
 I. a source of compressed gas;   II. a trigger mechanism configured to be actuated by an animal, the trigger mechanism including a trigger valve and a trigger rod, the trigger rod extending in a rest position from a mount at or near a first end thereof, the trigger rod being mounted for pivoting movement about the mount with two rotational degrees of freedom, and arranged such that pivoting movement of the trigger rod in any direction away from the rest position results in opening of the trigger valve and actuation of the trigger; and   III. a kill mechanism powered by compressed gas.   
     
     
         2 . An animal trap as claimed in  claim 1  wherein the trigger valve has a valve seat surrounding an opening and a valve member arranged to seal against the valve seat, and wherein the pivoting movement of the trigger rod in any direction away from the rest position results in relative pivoting movement between the valve member and the valve seat to open the trigger valve. 
     
     
         3 . An animal trap as claimed in  claim 1 , configured to reset after killing an animal. 
     
     
         4 . An animal trap as claimed in  claim 1  having a trigger threshold distinct from the rest position, such that the trigger rod may be moved from the rest position up to the trigger threshold without actuation of the trigger, but further movement of the trigger rod past the trigger threshold results in actuation of the trigger. 
     
     
         5 . An animal trap as claimed in  claim 1  wherein the trigger rod has a rod diameter less than 5 mm. 
     
     
         6 . An animal trap as claimed in  claim 1  wherein the trigger rod extends between 30 and 70 mm from the mount. 
     
     
         7 . An animal trap as claimed in  claim 1  including a biasing element configured to apply a restoring force that tends to maintain the trigger rod in the rest position. 
     
     
         8 . An animal trap as claimed in  claim 1  wherein the trigger rod has a mass less than  5  grams. 
     
     
         9 . An animal trap as claimed in  claim 1 , further including:
 i. an entrance; and   ii. a bait;   wherein the trigger rod extends in the rest position into a space between the entrance and the bait and the kill mechanism is configured to operate between the entrance and the trigger rod.   
     
     
         10 . A trap as claimed in  claim 9  wherein the entrance is dimensioned for a target animal. 
     
     
         11 . A trap as claimed in  claim 9  wherein the space in which the trigger rod extends is dimensioned such that an adult target animal cannot move past the rod without moving the trigger rod from the rest position. 
     
     
         12 . A pneumatically powered animal trap including:
 i. a source of compressed gas;   ii. a trigger mechanism configured to be actuated by an animal, the trigger mechanism including:
 a) a trigger valve including:
 i. an opening; 
 ii. a valve seat surrounding the opening; 
 iii. a valve member having a sealing surface; 
 iv. an O-ring arranged to seal between the sealing surface and the valve seat; and 
 v. an O-ring retainer configured to retain the O-ring on either the valve member or the valve seat; 
 vi. one or more flow paths allowing gas flow along at least part of an internal periphery of the O-ring; and 
 
 b) a trigger configured to open the trigger valve when actuated by an animal, the trigger operating to pivot the valve member so as to break the seal between the sealing surface and the valve seat;
 iii. a main valve; and 
 iv. a kill mechanism powered by compressed gas; 
 
   wherein opening of the trigger valve results in actuation of the main valve to allow compressed gas to flow to the kill mechanism.   
     
     
         13 . A trap as claimed in  claim 12  wherein the one or more flow paths include one or more channels, conduits, recesses, grooves, apertures or flutes along or communicating with the internal periphery of the O-ring. 
     
     
         14 . A trap as claimed in  claim 12  wherein the one or more flow paths are formed on the O-ring retainer. 
     
     
         15 . A trap as claimed in  claim 12  wherein the O-ring is a dynamic O-ring that deforms and/or moves under pressure when the trigger valve is opened. 
     
     
         16 . A trap as claimed in  claim 12  wherein the O-ring has an internal diameter less than 10 mm. 
     
     
         17 . A trap as claimed in  claim 12  wherein the O-ring has a radial cross-section that is less than 3 mm in width.