Abstract:
A fish stunning apparatus comprising a fish stunning device ( 100 ) including a striker ( 400 ); said striker ( 400 ) including a cylinder and a piston ( 443 ), said piston ( 443 ) movable between a retracted position and an extended position; a fish guide ( 200 ) having an entrance ( 230 ) and an exit ( 240 ); said fish guide ( 200 ) guiding a fish below said striker ( 400 ) so that said piston ( 443 ) contacts said fish when said piston ( 443 ) is in the extended position; trigger ( 300 ) to cause said piston ( 443 ) to be moved from the retracted position to the extended position when said fish is passed through said fish guide ( 200 ); wherein said fish is moved unidirectionally from said entrance ( 230 ) through said guide ( 200 ) to the exit ( 240 ). A fish guide ( 200 ) comprising an entrance ( 230 ), an exit ( 240 ) and a pivotally movable floor ( 220 ) and a table for distributing fish for stunning are also disclosed.

Description:
FIELD OF THE INVENTION 
     This invention relates to a fish stunning apparatus. In particular, the invention relates to a fish stunning apparatus including a fish stunning device, a fish guide and/or a fish delivery table. 
     BACKGROUND OF THE INVENTION 
     It has be found that by stunning fish, the quality of the flesh of the fish is increased as death does not induce the creation of lactic acid in the flesh of the fish. Fish are stunned in a number of ways including the most basic method of hitting the fish with a bat to using more complex devices in which the fish are stunned using a pneumatically driven ram. 
     In most commercial operated fisheries more complex pneumatic rams are used as they are more efficient and less physically demanding on an operator. An example of a fish stunning device that uses a pneumatic ram is disclosed in International Patent Application No WO 01/97621. 
     When fish are harvested, they are located in a holding area and then pumped onto a table. The fish are grabbed by an operator and stunned usually using a pneumatically driven stunning device that is mounted to the table. A guide is used to guide the head of the fish into the stunning device to activate a trigger to cause the pneumatic ram to be extended and stun the fish. The fish is then withdrawn from the guide and passed further along the table for other operations such as bleeding. 
     A problem with this process is that often the fish are pumped onto the table in waves. A large number of fish are often located on the table at one time creating a backlog of fish. An operator that uses the fish stunning apparatus shown in WO 01/97621 must push the fish forwardly through the guide in order to stun the fish. The difficulty arises when the fish must be removed as the backlog often hinders or sometimes prevents the removal of the fish. Further, as there is a passageway that must be provided to allow fish to be passed further along the table, fish that have not been stunned can be passed through this passageway which is undesirable. 
     OBJECT OF THE INVENTION 
     It is an object of the invention to overcome or alleviate the above disadvantages or provide the consumer with a useful or commercial choice. 
     SUMMARY OF THE INVENTION 
     A fish stunning apparatus comprising: 
     a fish stunning device including a striker; said striker including a cylinder and a piston, said piston movable between a retracted position and an extended position; 
     a fish guide having an entrance and an exit; said fish guide guiding a fish below the striker so that the piston contacts said fish when the piston is in the extended position; 
     a trigger to cause the piston to be moved from the retracted position to the extended position when the fish is passed through the fish guide; 
     wherein a fish is moved unidirectionally from the entrance through the guide to the exit. 
     The fish stunning device may be mounted to the fish guide using a mount. 
     The striker may include a head, a main body and a foot. 
     The cylinder may be located within the main body. The piston may be made integrally formed. 
     The main body may include a low-pressure chamber that is linked to a low-pressure inlet port and a high-pressure chamber that is linked to a high-pressure inlet port. 
     The head may include a control chamber that is linked to a control port. A control piston valve may be mounted within the head and may be movable between a striker position and a non-striker position. 
     An outlet port may be above the control piston valve to allow air to pass out of the head. 
     A passage way may extend through control piston valve to allow air to pass from the cylinder out the outlet. 
     A seal may be located above the passageway to seal the passageway when the control piston valve is in the striker position. 
     The foot has an aperture through which the piston extends when in the extended position. 
     A fish guide for guiding fish below a stunning device; said fish guide comprising: 
     an entrance for allowing fish to pass into the device; 
     an exit to allow fish to pass from the device; 
     a floor being pivotally movable between an first position and a second position; 
     wherein the floor moves from the first position to the second position to allow a fish to pass from the entrance to the exit. 
     The entrance and exit may be formed by a pair of side walls. The side walls may be diverging. 
     The floor may be pivotally movable using a mechanical device. The mechanical device may be at least one ram. The ram may be pneumatically driven. 
     A mounting means may be provided on the fish guide for mounting a fish stunning device thereto. The mounting means may be pins located on the side walls. 
     A table for distributing fish for stunning, said table comprising: 
     a reservoir for holding fish and water; 
     an inlet to introduce fish into the reservoir; 
     a weir to allow fish to pass from said reservoir; 
     a slide to distribute fish after they pass from the weir; and 
     a water flow device to add water to the reservoir 
     wherein the water flow device is orientated to add water in a direction away from the weir. 
     Preferably, the table also includes a drain to drain water that passes over the weir from the reservoir. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments, by way of example only, will be described with reference to the accompanying drawings in which: 
         FIG. 1  is a perspective view of a fish stunning apparatus according to an embodiment of the invention; 
         FIG. 2A  is a side view of the fish stunning apparatus according to  FIG. 1 ; 
         FIG. 2B  is a partial side sectional side view of the fish stunning apparatus according to  FIG. 1 ; 
         FIG. 3A  is a side sectional view of a striker in a first position; 
         FIG. 3B  is a side sectional view of the striker in a second position; 
         FIG. 3C  is a side sectional view of the striker in a third position; 
         FIG. 3D  is a side sectional view of the striker in a fourth position; 
         FIG. 4A  is a side sectional view of the fish stunning apparatus in a first position; 
         FIG. 4B  is a side sectional view of the fish stunning apparatus in a second position; 
         FIG. 4C  is a side sectional view of the fish stunning apparatus in a third position; 
         FIG. 4D  is a side sectional view of the fish stunning apparatus in a fourth position; 
         FIG. 5A  is a schematic drawing of the pneumatic circuit diagram used to operate a floor of a fish guide; 
         FIG. 5B  is a further schematic drawing of the pneumatic circuit diagram used to operate a floor of a fish guide; 
         FIG. 5C  is another further schematic drawing of the pneumatic circuit diagram used to operate a floor of a fish guide; 
         FIG. 5D  is yet another further schematic drawing of the pneumatic circuit diagram used to operate a floor of a fish guide; 
         FIG. 6  is a perspective view of a table for distributing fish according to an embodiment of the invention; 
         FIG. 7A  is a side sectional view of the table of  FIG. 6 ; and 
         FIG. 7B  is a further side sectional view of the table of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIGS. 1 ,  2 A and  2 B show a fish stunning apparatus  10  including a fish stunning device  100 , a fish guide  200  and a trigger  300 . 
     The fish stunning device  100  is mounted to the top of the fish guide  200 . The fish stunning device  100  includes a striker  400 , a control box  110 , a regulator  120  and an oiler  130  that are all mounted to a mount  140 . 
     The fish guide  200  includes a pair of side walls  210  and a pivotally mountable floor  220 . A front of the side wall defines an entrance  230  into which fish are passed and a back of the guides defines an exit  240  from which the fish are passed. 
     The fish stunning device  100  is mounted to the top of the fish guide using the mount  140  and pins  250  that are located on the side walls of the fish guide. The fish guide  200  include slots  141  that are able to be used to adjust the height of the striker  400  relative to the floor  220 . 
     The floor  220  is pivotally movable between a first position where the fish is located through the entrance  230  within the guide to be stunned and a second position where the fish is passed from the guide through the exit of the guide  240 . 
     The floor  220  is moved between the first and second position using a pair of pneumatic rams  260  connected to the underside of the floor  220 . 
     The trigger  300  is mounted adjacent the striker  400 . The trigger  300  is operatively connected to striker  400  and the floor  220 . A pin pneumatic ram  310  is connected to the trigger  300  to ensure that the trigger is fully engaged when activated. 
     The striker  400 , shown in more detail in  FIGS. 3A to 3D , is formed from a head  420 , a main body  440  and a foot  460 . 
     A pneumatic ram  441  is located within the main body  440  that includes a cylinder  442  and a piston  443  that is reciprocatable within the cylinder  442 . The piston  443  is made from a single piece of plastics that is easily removable and difficult to break. An O-ring  445  provides a seal between the cylinder  442  and the piston  443 . The piston  442  is movable between an extension position and retraction position. 
     The main body  440  also includes a low-pressure chamber  446  that is linked to a low-pressure inlet port  447  and a high-pressure chamber  449  that is linked to a high-pressure inlet port  448 . 
     The cylinder  442  is in fluid communication with the low-pressure chamber via a ring of holes  450  located at the bottom of the cylinder  442 . Two additional holes  451  located at the bottom of the cylinder  442  are also in fluid communication with the low-pressure chamber  446 . 
     The high-pressure chamber  449  extends into the head  420  of the striker  400  via an aperture  452  in the main body  440 . 
     The head  420  includes a control chamber  421  that is linked to a control port  422 . A control piston valve  423  is reciprocately mounted within the head  420  and movable between a striker position and a non-striker position. The pressure located within the control chamber  421  controls the movement at the control piston valve  423  between the striker and non-striker positions. 
     An outlet port  424  is located above the control piston valve  423  and allows air to pass from the head  420 . A passageway  425  extends through control piston valve  423  to allow air to pass from the cylinder out the outlet port  424 . A seal  426  is located above the passageway  425  to seal the passageway  425  when the control piston valve  423  is in the striker position. 
     The foot  460  has an aperture  461  through which the piston  443  extends when in the extended position. A Teflon, self-lubricating washer  462  is located within the foot to allow smooth reciprocation of the piston. 
     The striker operates in the following manner. The piston  443  starts in the retracted position with the control piston valve  423  in the non-striker position as shown in  FIG. 3A . The control piston valve  423  is held in the non-striker position by high-pressure air that is fed through the control port  422 . 
     The control port  422  is opened to allow pressure to be released from the control chamber  421  as shown in  FIG. 3B . This allows the control piston valve  423  to move into the striker position where the passageway  425  is sealed against the seal  426 . High-pressure passes from the high-pressure chamber  449  into the cylinder  442  to cause the piston  443  to be moved to the extended position as shown in  FIG. 3C . Air located within the cylinder  442  is passed out of the inlet port  447  when the piston  443  travels down the cylinder  442 . 
     When the piston  443  is close to the bottom of the cylinder  442 , air is passed through two holes  451  located within the cylinder  442 . This causes high-pressure air to be passed from within the cylinder  442  into the low-pressure chamber  446 . 
     When the piston  443  reaches the bottom of the cylinder  442 , high-pressure air is passed through the control port  422  into the control chamber  421  to move the control piston valve  423  to the non-striker position as shown in  FIG. 3D . 
     The air is feed in the low-pressure chamber  446  through low-pressure inlet port  447  and passes through the ring of holes  450  located within the cylinder  442  to cause the piston  443  to be retracted within the cylinder  442 . Air located within the cylinder  442  passes through the control piston valve  423  and through the outlet  424  to complete operation of the striker. 
     The regulator  120  supplies air to the ports  422 ,  448  of the striker using standard fittings such as those sold by FESTO. A smaller regulator  290  supplies low-pressure air through the port  447 . A pressure gauge  121  indicates that adequate pressure is being supplied through the regulator  120 . 
       FIGS. 5A to 5D  show a pneumatic circuit diagram showing the operation of the pneumatic rams  260  that control the operation of the floor  220 . It should be appreciated that in this embodiment that the operation of the striker and the floor  220  are timed so that the floor will drop after the piston  443  has reached its extended position. 
     The pneumatic circuit diagram shown is formed from a trigger valve  301 , floor ram valve  270 , timer valve  280  and regulator  290 .  FIG. 5A  shows the pneumatic circuit diagram prior to activation of the trigger  300 . 
     Once the trigger valve  301  is activated via the trigger valve  300 , as shown in  FIG. 5B , air expelled from the control chamber  421  through the control port  422  is passed through the trigger valve  301  to switch the position of ram valve  270 . Air is then supplied to the pneumatic rams  260  to cause the pneumatic rams  260  to lower the floor  220 . At the same time, air is used to switch on timer valve  280 . 
     Air is also supplied to the pin pneumatic ram  310  to cause the ram to be extended. The pin pneumatic ram  310  is provided such that the trigger becomes fully retracted whenever the floor ram valve  270  is switched to lower the floor  220 . In some instance, the trigger may not be fully engaged immediately. This will normally occur when a fish only lightly taps the trigger  300 . This will allow sufficient air to pass from the control chamber  421  through the control port  422  to switch the position of floor ram valve  270  but will not allow the piston  443  to be extended. By providing the pin pneumatic ram  310 , the piston  443  will always be moved to the extended position when the floor  220  is lowered. 
     The trigger is moved back to its original position after a fish activates the trigger as shown in  FIG. 5C . This causes air to pass from the pneumatic ram through the exhaust valve. 
     After a predetermined time, air is supplied through the timer valve  280  to switch the floor ram valve  220  to supply air to the pneumatic rams  260  to raise the floor  220  as shown in  FIG. 5D . 
       FIGS. 4A to 4D  shows the operating of the fish stunning apparatus  100 . 
     The fish stunning apparatus  100  operates by a fish being placed through the entrance  230  of the guide  200 . Once the fish is placed within the entrance  230 , the trigger  300  is depressed and the striker  400  is activated. 
     The piston  443 , located within the cylinder  442 , moves to the extended position hitting the fish on the head, stunning the fish. After the fish has been stunned, the floor  220  moves downwardly causing the fish to pass through the exit  240  at the back of the guide  200 . There is a slight delay between the piston  443  being fully extended and the floor  220  pivoting downwardly to ensure that the piston  443  stuns the fish. 
     The floor  220  is then moved back to its original position to allow for another fish to pass through the entrance  220  into the guide  200 . 
       FIG. 6  shows a table  500  for distributing fish for stunning. The table  500  includes a reservoir  510 , an inlet  520 , a weir  530 , a slide  540 , a drain  550  and a series of nozzles  560  that are directed outwardly from the weir  530 . 
     The reservoir  510  is formed from a pair of opposing side walls  511 , an end wall  512 , a base  513  and the weir  530 . The reservoir  510  holds water and fish until they are ready for distribution through the stunning apparatus  10  as shown in  FIG. 7A . 
     The inlet  520 , located in the base of the reservoir  510 , is used to pump fish and water into the reservoir  510 . 
     The weir  530  is at the front of the reservoir  510  and is used to allow fish to be passed from the reservoir  510 . The nozzles  560  are located along a face of the weir  560  and water is pumped through these nozzles  560  into the reservoir  510 . 
     A slide  540  extends from the front of the weir  530  to cause the fish to slide towards the fish stunning apparatus after they pass over the weir  510 . Chutes  580  ensure the fish are fed directly into the fish stunning apparatus  10 . The drain  550  is located at the lower end of the slide  540  and to drain any water that passes over the weir  530 . 
     A further drain  550  is located adjacent the end wall  512  of the reservoir  510 . A grate  571  extends the length of the end wall to allow water to pass from the reservoir into the drain  570 . 
     The table operates by pumping fish and water through the inlet  520  into the reservoir  510 . Water is passed through the nozzles  560  to create an artificial current that extends away from the weir  530  towards the grate  571  in the end wall  512 . The fish located within the reservoir  510  swim toward the current as is their natural tendency. Hence, the fish become aligned so that their head faces toward the weir  530 . 
     Increasing the flow of water through the nozzles  560  and/or inlet then increases the level of the water located within the reservoir  510  above the weir  530  as shown in  FIG. 7B . Water and fish are thus allowed to pass from the reservoir  510  over the weir  530 . The water flows through the chutes  580  and the fish continue to slide down the slide  540  through fish stunning apparatus  100 . 
     The fish flow over the weir  530  headfirst as they are facing the weir  530  prior to the level of water in the reservoir  510  being increased. As the fish travel head first over the weir  530  and down the slide, fish can be fed through the fish stunning machine automatically without the need to be fed manually. 
     The fish stunning apparatus  10  and table  500  provide the advantage of quick and efficient stunning of fish with minimal operator input and minimal stoppages. 
     It should be appreciated that various other changes and modifications may be made to the embodiments described without departing from the spirit or scope of the invention.