WO2010130262A2

WO2010130262A2 - Electronic pest eliminating device

Info

Publication number: WO2010130262A2
Application number: PCT/DK2010/050103
Authority: WO
Inventors: Hans Knudsen; Christian Thiim
Original assignee: ENVI-CON APS
Current assignee: ENVI-CON APS
Priority date: 2009-05-13
Filing date: 2010-05-12
Publication date: 2010-11-18
Anticipated expiration: 2011-11-13
Also published as: WO2010130262A3

Abstract

Pest electrocution device (1), especially for electrocution of rodents such as rats, mice and the like, where said device (1) comprises at least three electrodes (13, 14, 15) where a first electrode is connected to a first electrical pole and the other two electrodes are connected to an oppositely charged electrical pole, where said electrodes are arranged in a position where the pest will pass and thereby place its feet on at least two oppositely charged electrodes, characterized in that the device comprises a tunnel or a chamber (10) and a shield (2), where the electrodes (13, 14, 15) are arranged electrically insulated from each other and the tunnel or chamber (10), and where said electrodes (13, 14, 15) are suspended above the floor (11) of the tunnel or chamber (10), and that the shield (20) is arranged outside the tunnel or chamber (10), at least partly blocking the pest's route past the pest electrocution device (1).

Description

Electronic pest eliminating device

Field of the Invention

The present invention relates to a pest electrocution device, especially for electrocution of rodents such as rats, mice and the like.

Background of the Invention

In the art a number of different devices have been suggested for controlling pests such as rodents. Various methods are used in order to deter or exterminate the rodents, and particularly devices using electrical means in order to electrocute the pests have been suggested previously.

One such example is described in WO 2007/024143 where a rodent trap comprises a floor in which floor three electrodes are arranged. The electrodes are typically connected to a source of current providing between 2.8 and 4 kilovolts at 250 Hz. The trap is supplied with energy from 4 AA batteries. Furthermore a sensor is provided which sensor detects a rodent in the trap after which the sensor activates an electronic circuitry which exercises a so-called kill cycle. The electrodes are constantly maintained with a current such that as a rodent steps onto the electrode the conductivity between two electrodes changes dramatically which is the input the sensor uses in order to activate the kill cycle. After the kill cycle is completed the floor of the trap in which the electrodes are incorporated will turn, whereby the dead rodent will fall down under and outside the trap.

A further example is described in US 2006/0123693. The construction of this device is more or less similar to the one mentioned above with the difference that the electrodes embedded in the floor are connected to two separate electric circuits. The first circuit will induce a minimum current in the electrodes. As soon as a leak current is detected by electronic circuitry, the second electronic circuitry is activated whereby a relatively high current is conducted through the rodent placed on the electrodes. This will effectively electrocute the rodent. The first circuitry is supplied by for example a 12 volt battery of the type used in motorcycles whereas the second circuitry may be supplied with power from the power grid.

From US 2008/120895 is know a pest extermination device where the extermination means are arranged in a housing. In order to guide the pests, mainly rats into the housing, a plurality of flexible tubes are provided. The tubes acts as tunnels through which the rats may travel. In order to lure the rats to enter the tubes an appealable scent is distributed in the tubes. The device comprises extermination means, preferably be electrocution, and a refrigerated chamber for keeping the deceased pests. The execu- tion chamber is provided with preferably four electrodes arranged on platforms, in order to allow any liquid to drain away. Execution is effected by the pest interrupting a light neam in the chamber, thereby energising the electrodes.

This apparatus has two main drawbacks. Firstly the flexible tubes relies on the scent distribution to lure the pests into the tubes. This will only attract pests in the immediate vicinity, and furthermore the flexible tubes will very likely not be attractive to the pests as they perceive the flexibility as unsafe. Secondly, the electrode arrangement, having the electrodes mounted on platforms will clog up with foreign matter between the platforms. This in turn will make the electrodes short-circuit when energised, such mat the construction requires a substantial amount of maintenance in order to safeguard proper functioning.

A further device is disclosed in US 2,677,209. In this device a piece of exposed bait (cheese) shall lure the pest into the device. When the pest touches the bait, a plurality of switches and levers springsinto action an entices the pest to move into an extermination chamber, provided with a window. In this position electrodes integrated in the floor are activated, killing the pest. The integrated electrodes will, as is the case with some of the previously mentioned prior art devices become soiled and thereby the chances of short circuits and malfunction is increased. Furthermore the device must be serviced and cleaned regularly, as the bait may rot, the extermination chamber needs to be emptied and cleaned etc. In WO 2004/030450and WO 2007/121554 further prior art devices are described which all more or less are constructed in the same manner as already described above.

A general problem with these devices is the fact that either they consume power all the time, which puts a limit to how long the apparatus can operate without being serviced, or that there is a large amount of electronic equipment, sensors, control systems, communication modules etc., which makes them very fragile such that they are not suitable to be placed in an environment such as for example sewers and the like where often especially rats constitute a large problem. Finally, the constructions themselves do not foresee that pollution etc. may create circumstances in the traps which can lead to leak currents such that the trap may be activated without a rodent being present in the trap.

Furthermore, extensive tests carried out by the inventor of the present invention indi- cate that especially rats are very intelligent creatures which will communicate any dangers to other animals in the vicinity. For these purposes it is essential that a very fast and efficient execution of the rodent is effected before the rodent has a chance to communicate the presence of danger to other animals in the vicinity.

With many of the prior art devices mentioned above, leak currents, especially when such apparatuses are arranged in sewers with a very high humidity, will often warn the rodent that there is an unusual and potentially dangerous apparatus present.

Object of the Invention

It is therefore the purpose of the present invention to alleviate the disadvantages with the prior art devices and provide some further advantages which make the invention very efficient in use, ensures the complete electrocution of the rodent as fast as possible and ensures that the rodent reliably activates the apparatus without the creation of any leak currents or other unfortunate happenings which could alarm and scare off the rodents.

Description of the Invention

The present invention addresses this by providing a pest electrocution device , especially for electrocution of rodents such as rats, mice and the like, where said device comprises at least three electrodes where a first electrode is connected to a first electrical pole and the other two electrodes are connected to an oppositely charged electrical pole, where said electrodes are arranged in a position where the pest will pass and thereby place its feet on at least two oppositely charged electrodes, characterized in that the device comprises a tunnel or a chamber and a shield, where the electrodes are arranged electrically insulated from each other and the tunnel or chamber, and where said electrodes are suspended above the floor of the tunnel or chamber, and that the shield is arranged outside the tunnel or chamber, at least partly blocking the pest's route past the pest electrocution device.

By suspending the electrodes above the floor any moisture or other pollutants which may enter the pest electrocution device will not give rise to leak currents, which provides advantages in the shape of not using power when there is no pest present, not confusing any control, electronic circuitry and not scaring off the rodents in that they are very sensitive to currents. The elevation may be just one or two millimeters, but will be enough to isolate the electrodes completely from the floor of the tunnel, and at the same time the rodents will recognize the tunnel floor as a safe passage and therefore enter the pest electrocution device without hesitation.

In addition to this the shield arranged outside the tunnel or chamber to a certain degree blocks the possible passage for the rodents such that the apparent, only means for passing the obstacle is through the electrocution device tunnel.

In a further advantageous embodiment the floor and the electrodes are fastened to a rotating member, such that the electrodes in the shape of plates are suspended above the floor of the tunnel, and where the rotating member allows both the floor and the electrodes to rotate about a horizontal axis, and where release means are provided which release means interact by engagement and disengagement with the rotating member and/or the floor and/or the electrodes such that rotation of the rotatable mem- ber is only allowed when the release means disengages from interaction.

The rotating bottom of the tunnel or chamber serves to empty the electrocution device once the rodent has been killed. As the electrocution does not create any mess in the shape of blood, saliva or the like, the trap therefore does not need to be cleaned between each execution. By rotating the floor and thereby "dumping" the executed rodent out of the trap, the trap is immediately ready for reuse.

In a further advantageous embodiment the release means are in the shape of a permanent magnet which magnet is in contact with the floor and/or electrode plates, and where means are provided for supplying a current to the magnet thereby neutralizing the magnet, allowing the rotating member to rotate.

A permanent magnet will not require a source of energy in order to maintain the floor or electrode plates in their normal position, and by energizing the magnet, i.e. reversing the magnetic field, the floor and electrode plates will be released and allowed to rotate. During this rotation the dead animal will leave the electrodes and the floor whereby the trap is emptied.

In an alternative embodiment of the release means the release means comprises a replaceable or refϊllable reservoir of compressed air, which reservoir is in fluid contact which an air piston and cylinder, where the piston has means to engage and disengage the rotating member and/or the floor and/or the electrodes such that rotation of the rotatable member is only allowed when the means on the piston disengages from interaction.

Under some circumstances the permanent magnet may be arranged in an environment where moisture or other detrimental substances hampers the reliability of the magnet's ability to hold the floor and/or electrodes. In such environments it might be desirable to provide a mechanical release means, for example as described in this advantageous embodiment, in the shape of a mechanical means which engages the rotating member and/or the floor and/or the electrodes. When the engagement means are in engagement it will not be possible to rotate the rotating member, but as the engagement means is brought out of interaction, for example by being pulled back, the rotation means will be free to rotate, whereby a dead animal placed on the electrodes will be forced to leave the plate due to the forces of gravity. In one embodiment of this air piston and cylinder construction the refillable reservoir may be filled from a larger fluid gas res- ervoir. Alternatively, by using a replaceable reservoir, for example in the shape of a CC*2 cartridge similar to those used in inflateable lifepreservers a source of pressurized gas is provided. The activation pressure for the release means is a relatively low pressure and initial tests have indicated that the standard CO2 cylinders will be sufficient for more than 1500 activations.

In a further advantageous embodiment the rotating members are provided with a counter-weight, such that as the floor is rotated due to the weight of the executed animal, the animal will be tipped off, and the counterweight will cause the floor to rotate back into its normal position.

The counterweight ensures that as the executed pest has slid off the electrodes on the floor, the weight of the floor and the electrodes will be counterbalanced by the counterweight such that the floor will be rotated back into its initial position and engage the release means such that the pest electrocution device is ready to receive the next rat or other pest.

In a further advantageous embodiment the floor is divided in two halves , where the divide is parallel to the longitudinal direction of the tunnel or chamber, where the electrodes are arranged in combination with one of the two halves, and where means are provided for sliding the two halves in opposite directions, after the pest has been electrocuted.

For some types of pests, especially small pests such as mice and the like, the weight of the pest itself may not be sufficient to accomplish that the release means releases the floor and thereby rotates the floor whereby the pest is tipped off or that the counterweight due to constructional details is of a size which the mice may not be able to outweigh and thereby cause rotation. For these purposes it might be advantageous to provide a floor split into two halves which will slide out horizontally such that any pest or other matter being placed on the electrodes or floor will be "scraped off' by the sides of the chamber or tunnel. In this manner it is ensured under any circumstances when an electrocution cycle has been performed that the device will be effectively emptied and made ready for receiving the following pests. In a still further advantageous embodiment the depression of an electrode energizes the electrodes and activates an electronic circuit, which electronic circuit controls the electrocution of the pest.

By providing means which are actively activated it is ensured that a pest is present in the correct position before the electrocution cycle initiates. For some of the prior art devices the electrocution cycle or other means to exterminate the pests may be inadvertently activated by the pest before it is in the proper position. For example for rats which are relatively intelligent rodents this may give the rat the possibility to alarm other rats in the vicinity whereby the trap will be rendered more or less useless for a period until the warning from the rat has been forgotten by the other rats, which typically will take 5-8 days. Therefore, by providing a mechanical depression of the electrodes it is ensured that a pest is positively present inside the device in the correct po- sϊtion before the electrocution cycle is initiated. The chances of a successful result is hereby increased dramatically.

As an alternative to depression of the electrodes the invention in a further advantageous embodiment foresees that in the tunnel or chamber a suspended member incor- porating a magnet is provided in the pests path, such that as the pest engages the member the change in magnetic field will be detected by a Hall element, which thereafter energizes the electrodes and activates an electronic circuit, which electronic circuit controls the electrocution of the pest.

Like the embodiment mentioned before with the depression of the electrodes, an ensured mechanical activation is provided such that the electrocution cycle is not inadvertently activated.

In a further advantageous embodiment of the invention the electrodes are spaced hori- zontally with a gap of approx 10 mm between each electrode, and that an entrance plate is arranged in the same plane as the electrodes, which entrance plate serves to support the pest prior to entering the chamber or tunnel, and that the electrodes are suspended approx. 5 - 10 mm above the floor of the chamber or tunnel. The spacing and the elevation of the electrode from the floor ensures that the rodent will not short-circuit the electrodes with its feet and by elevating the electrodes from the floor any foreign substance such as saliva, excrements or other debris will not touch the electrodes and thereby cause leak currents or short-circuits. Furthermore, tests with the devices indicated that the elevation of the electrodes from the floor do not inhibit rats from entering the chamber or tunnel in that their curiosity appears to be bigger than the fear of the elevated electrodes. However, in situations where only electrodes were provided with a free view to the underlying sewer or ground the rats hesi- tated in entering the chamber or tunnel such that it appears necessary to also provide the underlying floor.

In order to efficiently electrocute the pests the following parameters should be adhered to such that the current potential between the electrical poles are 2 KV to 8 KV more preferred 3 KV to 5 KV, and that the current is between 10 mAnip and 40 mAmp, most preferred not more than 30 mAmp, and that electric current is maintained for a period of between 60 sec. to 180 sec, more preferred 75 sec. to 120 sec, and most preferred 120 sec.

Although the tests with the apparatus indicate that the electrocution of the rats is completed effectively after approximately 60 seconds, it is preferable to maintain the cycle for substantially longer in order to ensure that a complete electrocution of the rat has been achieved. This is due to the fact that the environment for example in a sewer may alter the conductivity of the rat such that in some instances it may be necessary to pro- long the circuit. For these purposes and in order to ensure an efficient extermination a substantially longer maintenance of the current is maintained. Furthermore, as the power consumption is relatively low, the power supply will be able to provide for a substantial number of electrocutions before being recharged or replaced.

Ln a still further advantageous embodiment the electronic circuitry is arranged in a separate housing, arranged remotely from the chamber or tunnel, and where said electronic circuitry optionally is connected to: - a source of renewably energy and/or; - an electrical power grid and/or;

- a GSM module for communication with a remote control station and/or;

- a Bluetooth wireless communication device.

As the inventive electrocution device is suitable for being placed above ground as well as below ground, for example in sewers, the electronic circuitry may be exposed to very varying environments. In a typical sewer the temperature will be relatively constant with a very high humidity. In these circumstances it is advantageous to arrange the fragile electronic circuitry remote from the trap itself. In this manner it becomes possible to arrange the electronic circuitry in a friendlier environment, also from a service point of view.

The provision of a GSM module or Bluetooth wireless communication device provides the further advantages of being able to wirelessly check on the trap, i.e. check for activity, failure or any other malfunction which may occur without having to dismantle the trap or even inspect the site on which the trap is placed.

In a still further advantageous embodiment the shield, substantially has a cross sectional area, corresponding to the passage in which the pest electrocution device is ar- ranged, or that the shield when the device is in use has a horizontal extent of 100mm to 350 mm and a vertical extent of 100 mm to 300 mm, and where optionally a shield may be arranged on either side of the chamber or tunnel.

Especially for devices arranged in sewers it is possible to provide a shield which sub- stantially blocks off the entire cross sectional area of the sewer such that the only opening left for for example rats is the chamber or tunnel in which the electrodes are arranged. In this manner a very high success rate may be achieved with the device. The shield is arranged in a hinge such that it does not hamper the liquid flow in the sewer, but solely serves to block the passage whereby the rats will be more or less forced to enter the device.

Above ground it is of course impossible to block the entire passage, and it is foreseen that rats will be able to pass the device without entering the chamber. However, by placing the shield such that the shield is adjacent a wall and the chamber or tunnel remote from the wall, tests indicate that usually the rodents will follow the wall and in this manner will encounter the shield whereby they will be diverted towards the device.

In a still further advantageous embodiment a bait station is arranged inside the chamber or tunnel in a position opposite the entrance to the tunnel or chamber, where said bait station, at regular intervals, may issue bait scents and/or that means are provided in front of the entrance to the tunnel or chamber where scent traces corresponding to the pest's urine, in particular rat urine, may be deposited.

The bait station is obviously provided in order to lure the rat to enter in the hope that there might be a source of food inside the chamber or tunnel. By furthermore or alternatively providing scent traces, typically in the shape of the pest's urine, the rats will feel safe to follow the route. Substantial studies of especially a rat's behavior indicated that rats will almost continuously lay down a track of urine scents such that other rats upon detecting the scents from the first rat will register that they are on a safe and proven track. In this manner, by laying out an artificial urine scent leading into the chamber or tunnel, this scent track will lure the pest into the device and thereby render the device more effective.

As already mentioned above, the invention is also directed to a method of using an electrocution device as mentioned above, where the different embodiments of the method as defined in the claims provides the advantages mentioned above with rela- tion to the device as such.

Description of the Drawing

The invention will now be explained in more detail with reference to the appended drawings wherein:

Fig. 1 illustrates a schematic view of an electrocution device;

Fig. 2 as fig. 1 with the shield in elevated position; Fig. 3 detail illustrating the arrangement of electrodes;

Fig. 4 schematically illustrates an embodiment of an activation device;

Fig. 5 and 6 further details of fig. 4;

Fig. 7a and 7b illustrate the ramp arranged on the shield; Fig. 8 illustrates a pest activating the trap in a further embodiment;

Fig. 9 illustrates a device installed in a sub-ground pipeline, with communication means near the surface.

Detailed Description of the Invention

In figure 1 is illustrated an embodiment of the invention suitable to be arranged in a sewer. The device 1 in this embodiment comprises a shield 2 which shield is bent to a diameter such that it will be able to press-fit the shield into a secure engagement with a sewer pipe. Inside the shield is arranged a tunnel or a chamber 10 as well as a further shield 20. The further shield 20 serves to block the path of rodents - in the following all rodents will be referred to as rats - such that the only opening accessible to the rats is the tunnel or chamber 10.

Inside the chamber 10 which is limited by the shield 2 the floor 11 and a sidewall 12 is provided further features of the invention which will be explained in detail with reference to figure 3.

The chamber or tunnel 10 is therefore limited by the shield 2, the sidewall 12 and the bottom 11.

In order to allow the liquids in the sewer to flow freely the shield 20 is mounted in a pivotable manner due to the pins 21 such that the shield may open as illustrated in figure 2. It is of course necessary to arrange the device correctly such that the view of the device depicted in figure 1 and figure 2 is looking upstream relative to the fiow of liquids in the sewer. In this manner it becomes possible for the shield 20 to pivot as illustrated in figure 2 and thereby allowing liquid and debris to pass unhindered past the device according to the present invention. In figure 3 are illustrated details of the electrocution construction according to the invention. In the illustration the inside of the tunnel or chamber 10 is illustrated such that the member behind the device is the inside wall of the shield 2.

The electrocution device comprises a floor 11 suspended above which three electrodes 13, 14, 15 are arranged. The electrodes are suspended above the floor 11 in order to avoid leak currents between the different electrodes 13, 14, 15 and/or the surrounding construction.

The electrodes 13, 14, 15 are mounted on a rotating member 16 which is rotatable around an axis 17. On the rotating member 16 is furthermore provided a counterweight 18 such that when no weight, i.e. a rat, is present on the electrode's 13, 14, 15 or the floor 11 , the counterweight 18 will ensure that the floor 11 is in contact with a permanent magnet 19 which will keep the rotating member from rotating. The permanent magnet 19 is furthermore strong enough to withstand the force should a rat place itself on the electrodes 13, 14, 15.

The electrodes 13, 14, 15 are fastened to the rotating member 16 by plastic screws (not illustrated) and with insulating layers 21 arranged between the electrodes and the rotating member. In this manner the electrodes are completely isolated from the surrounding construction such that the risk of leak current which could deplete the batteries or the initiate electrocution cycles is avoided.

In front of the electrodes 13, 14, 15 is arranged an entry plate 22 which serves to accommodate the rat upon entry into the tunnel or chamber. Experiments have shown that if a rat enters the trap without the entry plate 22, it may depress the electrodes and thereby activate the electrocution cycle before being correctly placed inside the chamber or tunnel as will be explained below. Therefore by providing the entry plate 22 the rat will step on this before being ready to enter the trap. The likelihood of the rat entering the trap with such an entry plate is therefore greatly increased. The electrodes 13, 15 are connected to the electrode 14 such that an electrical potential is created between the different electrodes.

In practice the electrodes are made from stainless steel, and the bottom is made from plasties. These materials are chosen such that the device will not corrode when exposed to the aggressive and moist environment in for example a sewer. Naturally the electrodes may also be made from a conductive polymer or any other suitable material, as may the bottom.

As a rat steps onto the electrodes, for example electrodes 13 and 14, a slight depression is detected of the electrodes, whereby the electrocution cycle is initiated. As the rat will typically have its front paws on electrode 14 and its rear paws on electrode 13 the rat being conductive, a short-circuit will occur whereby the current, for example 3 ldlovolts at up to 30 millϊamperes will enter the rat which will be killed by the current. The electrocution cycle furthermore starts a timer such that the current through the rat will be maintained for up to 120 seconds. At the end of the 120 seconds a current is induced in the permanent magnet 19 which thereby looses its magnetic capability and the electrodes 13, 14, 15 and the floor 11 will rotate in that the weight of the rat on the electrodes will counter the counterweight 18 such that the floor and the electrodes will be rotated into a substantially vertical position due to the weight of the rat whereby the rat will be tipped off the electrodes. At this point the weight is lessened on the electrodes and the floor plate 1 1 such that the counterweight 18 will rotate the rotating member 16 around the axis 17 back into engagement with the permanent magnet 19 which at this time is no longer energized and therefore will be magnetic and attach the bottom plate 11 to the permanent magnet in a firm hold. In this position the electrocution device according to the invention is ready to receive a further rat.

In some instances the permanent magnet may be unstable, especially if the electrocution device is arranged in positions where a lot of debris may be present on the floor plate such that the contact area between the floor piate 11 and the permanent magnet 19 may be polluted. In these instances a release mechanism as illustrated in figure 4 may be used. In this figure certain elements have been removed in order to illustrate the system. At the end of the tunnel opposite the entrance opening where the rodent is supposed to enter the device an upstanding plate 25 has been arranged in connection with the floor 11. In the plate an aperture 26 is provided. The aperture 26 will be engaged by a pin 27 which pin is connected to a piston arranged inside an air cylinder 28.

The pin 27 is provided with a slanted end such that it will engage on the side of the aperture 26 and thereby force the plate 25 towards the right as illustrated in the figure. During this movement a helical spring 29 will be lightly biased. The air cylinder 28 is connected by an air hose 30 to an air reservoir 31 where air is kept under pressure. In the air hose 30 is provided a pressure regulator and a magnet valve 33. The air pressure regulator 32 doses the amount of air and the pressure of the air such that the air in the reservoir 31 is used as economically as possible. The magnet valve is activated after the electrocution cycle is completed such that the pin 27 is withdrawn from the aperture 26 whereby the floor 1 1 with the electrodes and the electrocuted rat is rotated emptying the rat for example into the sewer below the device. As the rat is emptied form the floor 11 the counterweight will as already explained above rotate the bottom plate 11 back to its original position. The pin 27 due to its engagement with the side of the aperture 26 will bias the spring 29. As the pin 27 is withdrawn from the aperture 26, the biased spring 29 will initially push the plate 25 and thereby the bottom plate 1 1, and in this manner initiate the rotation which leads to emptying of the rat from the device. A connection 34 may be provided either to a constant source of pressurized air or for refilling purposes such that it is easy to refill the reservoir 31. The box 35 containing the air supply, the magnet valve, pressure regulator and electronics may be positioned in a remote position as will be explained with reference to figure 9.

A further device to initiate and release the rotation of the floor is illustrated with reference to figures 5 and 6, In this embodiment the weight of the rat will provide the energy necessary to drive the release arrangement. As a rat enters the device according to the present invention and exerts a force upon the floor plate 1 1 or in fact the electrodes 13, 14, 15, the weight of the rat will urge the floor plate 11 as well as the electrodes downwards. A pendulum arm 36 attached to the rotating member 16 will pull on an upper bellows arranged in the release mechanism 40. The release mechanism 40 is made from two connected bellows 37. 38 which are both filled with a viscous liquid such as for example silicon oil. As the pendulum arm 36 is moving downwards as indicated by the arrow 39, the oil from the upper bellow 37 will be forced through the connection 41 into the lower bellow 38. The downwards move- ment 39 of the electrodes 13, 14, 15 and the bottom 1 1 takes place while the rat is situated on the electrodes and being electrocuted. As the pendulum arm 36 reaches its lowermost position indicated by dashed lines, the bottom 11 and thereby the electrodes 13, 14, 15 will be released and be free to swing downwards into a position where the rat will be forced off the plates 13, 14, 15. Ln this position the counterweight will force the plates upwards again whereby the pendulum arm 36 will be urged upwards and thereby forcing the oil to be moved from the lower bellows to the upper bellows 38, By dimensioning the connection 41 appropriately it is possible to create a delay in the release of the plates 13, 14, 15 and the bottom plate 1 1 such that the rat will be present 2 minutes on the electrodes before it is completely released. The 2 minutes delay in the release is due to the time it takes the oil to move from the upper bellow 37 through the connection 41 and into the lower bellow 38. By dimensioning the connection 41 differently other delays may be accomplished.

In figure 7A and 7B is illustrated a further advantageous positioning of the device, for example in a sewer. The shield 20 is here arranged substantially centrally in the sewer with the outer shield engaging the sewer pipe (not illustrated). In order to allow the rats to reach the tunnel/chamber 10 a path 42 is provided in order to allow the rats easy access to the chamber 10.

In figure 8 is illustrated an alternative embodiment on how to activate the electronic circuitry which will initiate the electrocution cycle. Inside the tunnel or chamber 10 is provided a pendulum 43 which may rotate. On a lower section of the pendulum is arranged a magnet 45 such that as the pendulum 43 rotates, the magnet will be brought into the vicinity of a hall element 46. The hall element will detect the change in mag- netic field and forward this as input to the electronic circuitry whereby the electrocution cycle may be commenced. The rotation of the pendulum 43 may be initiated by a rat 44 pushing the pendulum 43 in order to gain access to the back of the tunnel 10. In the previous embodiments the invention has been explained with reference to the device being installed in a sewer installation. In practice the sewer may be as illustrated with reference to Figure 9. The device 1 is arranged in a sewer where the flow of liquid in the sewer is as indicated by the arrows 47. As a rat indicated by the letter R travels up the sewer against the flow indicated by the arrow 47 it will encounter the shield 20 and therefore enter the chamber or tunnel 10. In this manner it will initiate the electrocution cycle as described above in any of the embodiments of the invention. In this embodiment the electronic circuitry 48 is arranged remotely in a manhole 49 such that access to the electronic circuitry 48 may be gained from the surface 50 by simply removing manhole cover 5L A power supply 52 is provided adjacent the manhole cover such that easy replacement of for example a battery may be accomplished without entering into the manhole as such.

Although the invention has been explained with reference to being arranged in a sewer below the surface 50 it is clear that the same principles relating to the electrocution device may be utilized for devices placed above ground and the invention shall therefore only be limited by the scope of protection as defined in the appended claims.

Claims

1. Pest electrocution device, especially for electrocution of rodents such as rats, mice and the like, where said device comprises at least three electrodes where a first elec- trode is connected to a first electrical pole and the other two electrodes are connected to an oppositely charged electrical pole, where said electrodes are arranged in a position where the pest will pass and thereby place its feet on at least two oppositely charged electrodes, characterized in that the device comprises a tunnel or a chamber and a shield, where the electrodes are arranged electrically insulated from each other and the tunnel or chamber, and where said electrodes are suspended above the floor of the tunnel or chamber, and that the shield is arranged outside the tunnel or chamber, at least partly blocking the pest's route past the pest electrocution device and where the floor and the electrodes are fastened to a rotating member, such that the electrodes in the shape of plates are suspended above the floor of the tunnel, and where the rotating member allows both the floor and the electrodes to rotate about a horizontal axis, and where release means are provided which release means interact by engagement and disengagement with the rotating member and/or the floor and/or the electrodes such that rotation of the rotatable member is only allowed when the release means disengages from interaction.

2. Pest electrocution device according to claim 1, characterized in that the release means are:

-in the shape of a permanent magnet which magnet is in contact with the floor and/or electrode plates, and where means are provided for supplying a current to the magnet thereby neutralizing the magnet, allowing the rotating member to rotate or where;

- the release means comprises a replaceable or refillable reservoir of compressed air, which reservoir is in fluid contact which an air piston and cylinder, where the piston has means to engage and disengage the rotating member and/or the floor and/or the electrodes such that rotation of the rotatable member is only allowed when the means on the piston disengages from interaction or where

- the release mechanism is made from two connected bellows, which are both filled with a viscous liquid where a pendulum arm is connected to the a lower bellows such that as the pendulum arm is moved in a first direction the viscous liquid from the upper bellow will be forced through a connection into the lower bellow, where the pendulum arm is moved in the first direction by the rotation of the electrodes and the bottom and where movement in the opposite direction is caused by the counterweight thereby forcing the viscous liquid to be moved from the lower bellows to the upper bellows.

3. Pest electrocution device according to any of claims 1 or 2 characterized in that the rotating member is provided with a counter-weight, such that as the floor is rotated due to the weight of the executed animal, the animal will be tipped off, and the counterweight will cause the floor to rotate back into its normal position.

4. Pest electrocution device according to claim 1 characterized in that the floor is divided in two halves, where the divide is parallel to the longitudinal direction of the tunnel or chamber, where the electrodes are arranged in combination with one of the two halves, and where means are provided for sliding the two halves in opposite directions, after the pest has been electrocuted.

5. Pest electrocution device according to any of claims 1 to 4 characterized in that ei- ther a depression of an electrode energizes the electrodes, and activates an electronic circuit, which electronic circuit controls the electrocution of the pest or where activation is obtained in the tunnel or chamber by a suspended member incorporating a magnet provided in the pests path, such that as the pest engages the member the change in magnetic field will be detected by a Hall element, which thereafter energizes the elec- trodes and activates an electronic circuit, which electronic circuit controls the electrocution of the pest.

6. Pest electrocution device according to any preceding claim characterized in that the electrodes are spaced horizontally with a gap of approx 10 mm between each elec- trode, and that an entrance plate is arranged in the same plane as the electrodes, which entrance plate serves to support the pest prior to entering the chamber or tunnel, and that the electrodes are suspended approx. 5 - 10 mm above the floor of the chamber or tunnel.

7. Pest electrocution device according to claim 6 characterized in that the electronic circuit is arranged in a separate housing, arranged remotely from the chamber or tunnel, and where said electronic circuitry optionally is connected to: - a source of renewably energy and/or;

- an electrical power grid and/or;

- a GSM module for communication with a remote control station and/or;

- a Bluetooth wireless communication device

- a battery.

8. Pest electrocution device according to any preceding claim characterized in that the shield, substantially has a cross sectional area, corresponding to the passage in which the pest electrocution device is arranged, or that the shield when the device is in use has a horizontal extent of 100mm to 350 mm and a vertical extent of 100 mm to 300 mm, and where optionally a shield may be arranged on either side of the chamber or tunnel.

9. Pest electrocution device according to any preceding claim characterized in that a bait station is arranged inside the chamber or tunnel in a position opposite the entrance to the tunnel or chamber, where said bait station, at regular intervals, may issue bait scents and/or that means are provided in front of the entrance to the tunnel or chamber where scent traces corresponding to the pest's urine, in particular rat urine may be deposited.

10. Method for the electrocution of a pest, in particular a rodent by use of a device according to any of claims 1 to 10 where said device comprises at least three electrodes where a first electrode is connected to a first electrical pole and the other two electrodes are connected to an oppositely charged electrical pole, where said electrodes are arranged in a position where the pest will pass and thereby place its feet on at least two oppositely charged electrodes, characterized in that the device comprises a tunnel or a chamber and a shield, where the electrodes are arranged electrically insulated from each other, and the tunnel or chamber, and where said electrodes are suspended above the floor of the tunnel or chamber, and that the shield is arranged out- side the tunnel or chamber, at least partly blocking the pest's route past the pest electrocution device where when a pest enters the tunnel or chamber, the pest activates an electronic circuitry, whereby a current of 5 to 10 KV and up to 30 mAmp passes through the pest, and after a predetermined period release means are activated allow- ing the floor and electrodes to rotate, whereby the electrocuted pest falls out of the tunnel or chamber.

1 1. Method according to claim 10 where after the pest has fallen out of the tunnel or chamber thereby removing the load from the electrodes and/or floor, a contra weight mounted on the rotating member will cause the electrodes and floor to rotate back into its original position, and engaged the now not energized permanent magnet.

12. Method according to claim 1 1, where the device is arranged in a sewer, and where the shield substantially blocks the cross section of said sewer apart from the tunnel or chamber, and where the shield is pivotably arranged, allowing liquid to pass unhindered in one direction, but may not be pivoted in the opposite direction.