Abstract:
The present portable exterminating apparatus uses an ignite charge of gas to produce both concussion and heat within the burrow of a rodent, along with residual toxic fumes, all contributing to rodent extermination. The apparatus includes a barrel, an injection control assembly, an ignition system, and a safety system including a pressure sensor and preferably a check valve. The mixing chamber of the apparatus mixes a flammable gas, such as propane, with oxygen, preferably from a bottled oxygen source, at a desired ratio. The barrel nozzle is placed into the burrow opening, and the flammable mixture is discharged into the burrow, and subsequently ignited. The ignition system including a battery, an ignition switch, and an improved ignition component inducing arcing across a pair of electrodes located within the nozzle of the barrel. The ignition switch is preferably located near the discharge valve for one-hand operation of the apparatus. The pressure switch prevents ignition of the mixture until the pressure of the mixture in the upper barrel has dropped after the operator has closed the discharge valve.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to devices for the extermination of rodents. More specifically, the present invention is a device for the injection of a flammable gas into burrows of rodents and the subsequent detonation of said gas, thereby eradicating the rodents. 
     2. Related Art 
     Burrowing rodents are well know for making underground passageways, referred to as burrows, and holes extending from these burrows to the surface of the ground. Burrowing rodents cause many problems for property owners, farmers and ranchers. Burrowing rodents cause: damage to growing crops, lumber and landscapes by destroying plant root systems and eating vegetation; damage to canals and other waterways by digging holes through the sides of such waterways, resulting in lost water rights and flooding; wear and tear on equipment (such as tractors) which often need to drive across burrow and hole pockmarked fields; increased erosion; and physical harm to humans and animals who accidentally step within rodent holes or whose steps break through the surface of the ground, breaking through to a burrow causing injury to the human or animal unlucky enough to step in such. 
     Burrowing rodents being pests and causing such damage has resulted in property owners, ranchers and farmers eradicating the rodents themselves or paying to have the rodents eradicated. Such “rodents” including: prairie dogs, gophers, and ground squirrels. 
     Known exterminating apparatuses and methods for eliminating rodents include the use of traps and poisons. However, the use of traps has been found to be both uneconomical and unreliable, and the use of poisons is not desirable due to the effects on the environment and effects on other animals which eat poison coated vegetation, eat living rodents who have consumed some amount of the poison, and even scavengers which eat the carcasses of rodents killed through the use of such poison. 
     Inefficiencies and problems with the prior ways of exterminating rodents lead to the invention of a gas fired apparatus for discharging an inflammable gaseous vapor into the rodents&#39; burrows and igniting the mixture, such as is shown in Rombach et. al., U.S. Pat. No. 4,005,976. However, drawbacks in the technology shown in Rombach et al. include a lack of portability, a need for greater simplicity, the failure to use safety devices such as a check valve or a pressure sensor, and the lack of the use of an oxygen source in conjunction with the inflammable gas. 
     Another known invention was discovered by the inventors, and discussed further infra. The invention comprises a rodent extermination device having both oxygen and inflammable gas inputs, but failing to have safety devices, such as a check valve or pressure sensor. This prior art version also utilized an ignitor requiring the use of an automobile or automobile battery in order supply the required electrical current. Such a requirement greatly reduced the portability of the device. 
     What is needed is a gas fired apparatus for discharging a mixture of inflammable gas and oxygen vapors into rodents&#39; burrows and igniting the mixture that also has the safety features of a pressure sensor and having an improved ignition system. 
     SUMMARY OF THE INVENTION 
     The present invention is embodied within a portable exterminating apparatus using an ignited charge of gas to produce both concussion and heat within the burrow, along with residual toxic fumes, all contributing to rodent extermination. The heat, concussion and toxicity produced by the present apparatus have a cumulative effect which greatly increases its effectiveness. 
     The present invention comprises: a barrel, an injection control assembly, an ignition system, and a barrel system. 
     The barrel from the barrel system of the apparatus is positioned for insertion of its nozzled end into a burrow, or other closed area, opening facilitating discharge of a mixture of oxygen and an inflammable gas into the rodent&#39;s burrow and the subsequent ignition of this mixture. The injection control assembly includes a mixing chamber allowing for the mixing of an inflammable gas, such as propane, with oxygen, preferably from a bottled oxygen source, at a desired ratio. This ratio being variable by means of pair of adjustable valve members, one regulating the oxygen intake opening and the other regulating the gas intake opening. This mixture is then discharged by the user, while the apparatus is in use, into the barrel through use of a discharge valve. The ignition switch is conveniently located near the discharge valve for convenient one-hand operation of the apparatus. The ignition switch is part of the ignition system further comprising a battery and an ignition component inducing arcing across an igniter, such as the preferred electrodes located within the nozzled end of the apparatus. Upon injecting a quantity of the mixture into the burrow, the user ignites the mixture by depressing the ignition switch. 
     Important objects of the present apparatus include: the provision of an extermination apparatus discharging a quantity of a gas/oxygen mixture into a burrow and thereafter igniting same to impart both concussion and heat to the burrow which along with the residual toxic fumes assure extermination of the rodent or rodents; an extermination apparatus having adjustable valve members to regulating the intake and subsequent mixture of oxygen and gas for optimum ignition; the provision of an exterminating apparatus wherein both ignition and gas/oxygen flow control means are incorporated conveniently for operation in a single handed manner; and the safety resulting from the combination of the use of a check valve keeping the mixture within the barrel from being ignited and a pressure sensor keeping the exterminator from firing until the user has stopped the release of the mixture into the burrow, and the use of an improved ignition system. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings: 
     FIG. 1 is a side view of an article of  PRIOR ART  discovered by the inventors. 
     FIG. 2 is a side view of the present invention in use, shown inserted into a burrow. 
     FIG. 3A is a side, partial, cross-sectional, detail view of the injection control assembly end of one embodiment of the present invention. 
     FIG. 3B is a side, partial, cross-sectional, detail view of the ignition system and center of one embodiment of the present invention. 
     FIG. 3C is a side, partial, cross-sectional, detail view of the nozzled end of one embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the present invention, the following terms have the following meanings, unless explicitly noted otherwise: “proximal” refers to the injection control assembly end of the present invention and “distal” refers to the nozzle end of the present invention. 
     The present invention is a portable rodent extermination apparatus comprising an injection control assembly  20  for controlling the injection of a mixture of oxygen and an inflammable gas, such as propane, into a rodent burrow; an ignition system  30  for igniting said mixture in said burrow; and a barrel system  40  for transfer of the mixture from the injection control assembly to the burrow. 
     FIG. 1 shows a prior art device that the inventors purchased via mail order, from Rid-A-Rodent, Inc. in Elko, Nev. The inventors have been unable to confirm whether the device is patented, but have seen recent advertisements marked Patent pending. The prior art device uses an automobile coil C connected via a 25′ long cable to a 12-volt automobile battery B for increasing the voltage and a common automotive sparkplug S for generation of the ignition spark. By needing a connection to an automobile battery, the prior art device has a portability range only within a 50′ arc. However, the present invention has at least a portability range within a 100′ arc (when the present invention is used with 50′ long supply lines) and possibly fully portable through the use of a backpack for carrying a pair of small tanks, one for the gas supply and one for oxygen. The prior art device also failed to have a pressure sensor like the present invention, undesirably and unsafely allowing the user to ignite the mixture while still releasing additional quantities of the mixture. Another flaw within the prior art version was the location of the ignition switch in relation to the injection trigger. In the prior art version, the ignition switch was located adjacent to the injection trigger, often leading to accidental release of a mixture of gas and oxygen and its accidental ignition. 
     As shown in FIG. 2, the present invention  100  connects to an oxygen source  80 , such as an oxygen tank. The present invention  100  also connects to an inflammable gas source  82 , such as a propane tank. A flexible oxygen supply line  84  extends from the oxygen source  80  and to the present invention  100 , attaching into the injection control assembly  20  at a second adjustable means  26 , as shown in FIG.  3 A. Referring back to FIG. 2, a flexible gas supply line  86  extends from the gas source  82  and to the present invention  100 , attaching into the injection control assembly  20  at a first adjustable means  24 , as shown in FIG.  3 A. The supply lines  86 ,  84  are preferably less than or equal to 50′ long. Both supply lines  84 ,  86  flow through one-way valves  81 ,  83  before their attachment with the first and second adjustable means  24 ,  26 . These one-way valves  81 ,  83  keep mixture from flowing backwards through the adjustable means  24 ,  26  and into the supply lines  84 ,  86 . The preferred one-way valves are Forney #87147 valves. FIG. 2 also shows the use of a preferred handle H, which is preferably of such a size that the user can rest his or her leg against the handle to add stability to the invention when the invention is fired. 
     As shown in FIG. 3A, and as mentioned above, the injection control assembly  20  includes a pair of adjustable means or valves  24 ,  26 , the first  24  of which controls the input of gas and the second  26  of which controls the input of oxygen into the present invention. The preferred controls are turn knob dials allowing the user to merely turn a dial in order to increase or decrease the amount of oxygen or gas released. 
     The preferred mixture is created through the following process: first the regulator on the oxygen source  80  is set at 30 pounds of pressure and the regulator on the propane source  82  is set at 15 pounds of pressure. Then, starting with both means  24 ,  26  in the closed position, the first adjustable (gas) means  24  is opened by turning the knob on the means  24  one-quarter rotation, and the second adjustable (oxygen) means  26  is opened by turning the knob on the means  26  one and one-half rotations. Such a set up yields the proper mixture, causing an explosion of the mixture when ignited and not resulting in burning of the mixture. 
     A mixing chamber  28  connects to these adjustable means  24 ,  26 . Said mixing chamber  28  serves as a reservoir where the quantities of gas and oxygen are mixed with one another. The discharge valve  23  connects to the mixing chamber  28 . Actuation of an injection trigger or handle  22  causes the opening of the discharge valve  23 , and the release of a quantity of the mixture into the connected upper barrel  41  of the barrel system  40  of the present invention  100 . Continuous actuation of the trigger  22  has the result of releasing a continuous amount the mixture into the upper barrel  41 . 
     The preferred injection control assembly  20  is a Forney torch handle, part number 87093. The preferred mixing barrel and adjustment means is an one-piece article is known as a Forney mixing tip, part number 87795. 
     Referring to FIGS.  3 A- 3 C, the barrel system  40  of the preferred embodiment of the present invention  100  comprises an upper barrel  41 , a check valve  46 , a lower barrel  43 , and a barrel shroud  48 . The upper barrel  41  connects to the mixing chamber  28 . Such connection is preferably done through a threaded outer surface of the proximal end of the upper barrel  41  received into a thread receiving portion of the mixing chamber  28 . The mixture flows out of the mixing chamber  28  and into the upper barrel  41 . The upper barrel  41  is a narrow and elongated piece extending away from the injection control assembly  20 , through the ignition protective shroud  38  (as shown in FIG.  3 B), and to the nozzled end of the present invention. As shown in FIG. 3C, preferably, the end of the upper barrel  41  opposite the injection control assembly  20  has a slight bend within it allowing for easier insertion into the ground of the nozzle system  44  end of the apparatus. Rather than a bend, an elbow-type joint or other method could be used. 
     Referring to FIG. 3C, connecting in-line near the distal end of the upper barrel  41  is a check valve  46 . Such connection is preferably done through a threaded outer surface of the distal end of the upper barrel  41  being received into the proximal end of the check valve  46 . The check valve  46  serves to prevent the back flow of ignited mixture into the upper barrel  41  and upwards towards the user and the source of the gas  82 . The check valve  46  is a one-way valve allowing the mixture to only travel from the upper barrel  41  through the check valve  46  and into the lower barrel  43 . The preferred check valve  46  is a National Torch Tip model FA-10 which opens when 3.0 ounces of pressure are present, and closes when the pressure within the barrel system  40  drops below 3.0 ounces of pressure. Ten ounces of back pressure will cause this model check valve to close as well. 
     In use, as the user depresses the injection trigger  22 , the mixture is released from the mixing chamber  28  and is allowed to travel into the upper barrel  41 . The pressure of the mixture flowing through the upper barrel  41  causes the check valve  46  to open as the mixture reaches the check valve  46 . The mixture then flows through the check valve  46 . When the user deactivates the injection trigger  22 , the pressure within the barrel drops, causing the check valve  46  to close, thereby inhibiting ignited mixture from traveling up the barrel system  40 . 
     Connecting in-line to the distal end of the check valve  46  is the proximal end of the lower barrel  43 . Such connection is preferably from a threaded protuberance extending from the distal end of the check valve  46  being received into a threaded inner portion of the lower barrel  43 . The lower barrel  43  may comprise an elongated section or may only comprise a connection between the check valve  46  and the nozzle system  44 . Mixture passing through the check valve  46  is able to pass through the lower barrel  43 . The distal end of the lower barrel  43  connects to the nozzle system  44 . Preferably, such connection connects the lower barrel  43  to a nozzle cap  47 . Such connection is preferably done through the threading of threads located on the outside surface of the distal end of the lower barrel  43  into threads located within the proximal end of the nozzle cap  47 . 
     The nozzle system  44  preferably comprises: a nozzle  45  and a nozzle cap  47  inserted and affixed within the nozzle  45 . The nozzle cap  47  serves to center the distal end of the lower barrel  43  in the nozzle  45 . The nozzle cap  47  also serves as the location where the electrodes  36 ,  36 ′ from the igniter  35  of the ignition system  30  are located. 
     The electrodes  36 ,  36 ′ extend generally distally and inward from the distal surface of the nozzle cap  47 . The electrodes  36 ,  36 ′ are preferably located within the nozzle  45  a short distance apart so that when the ignition system  30  is activated, a spark will be able to arc from one electrode  36  to the other  36 ′. Such arching takes place at the distal end of the electrodes  36 ,  36 ′. If a quantity of the mixture is present in the burrow when this arcing happens, then the mixture will be ignited. Preferably these electrodes  36 ,  36 ′ are made of bent brass screws, however other electrodes are also envisioned. Preferably these electrodes  36 ,  36 ′ are located 0.25 to 0.5 inches apart. 
     Preferably, the proximal end of the nozzle  45 , which contains the nozzle cap  47  and electrodes  36 , is filled with a high temperature glue or other material, so as to inhibit the transmittal of mixture from within the burrow to upwards inside the barrel protective shroud  48  of the barrel and into the ignition protective shroud  38 , and to solidify and strengthen the nozzle system  44 . 
     The proximal end of each of the electrodes  36 ,  36 ′ attach to an ignition wire  31  through the common method. The ignition wires  31  extend from their connection with the electrodes  36 ,  36 ′ along the barrel system  40 , through the barrel protective shroud  48 , and into the ignition protective shroud  38  which serves to protect the ignition system  30  from damage. 
     The protective shrouds  38 ,  48  are preferably made of PVC or other lightweight plastic. The ignition protective shroud  38  serves as the location where the ignitor  35 , battery  37  and ignition switch  33  are attached and located. Preferably, the shroud  38  is able to be opened and closed, giving the user  90  access to the internal components. Preferably, the shroud  38  is water-tight protecting the internal components from moisture. Preferably, the ignitor  35  is located within the shroud  38  and the ignition switch  33  extends through and is attached to the shroud  38 , allowing the user to activate the ignition switch  33  without opening the shroud  38 . Preferably, the battery  37  is located within a separate battery box  73  allowing the user to easily change the battery  37  without needing to open the ignition shroud  38 . Preferably, a pair of batteries are used to extend the length of time the invention can be used without replacing the batteries. 
     Referring to FIG. 3B, the ignition wires  31 ,  31 ′ connect with the ignitor  35 . This is done by one ignition wire  31  connecting to a first output terminal  60 , and the second ignition wire  31 ′ connecting to a second output terminal  62 . The preferred ignitor  35  comprises a common stun gun, such as shown in U.S. Pat. No. 4,668,140, and related patents. With a common stun gun, when the stun gun&#39;s switch is depressed, a battery, commonly a 9-volt battery, delivers a charge to the basic electronic circuit in the device which produces a pulse utilizing a non-linear relaxation oscillator producing approximately twenty pulses per second. Additional components of a common stun gun include a transistor, diodes, and an oscillator transformer which creates a charge across a capacitor. Once the arc potential of an internal spark gap is reached, a magnetic field in the oscillator transformer collapses suddenly to create a brief high voltage pulse across the output terminals. Generally, such a device comprises a mechanism designed to emit a pulsing high voltage, low amperage pulse or charge, including devices that achieve this through electronic, magnetic, phase induction, laser, and other types of charges. Such stun gun technology is not part of the invention except as it is recited in the following claims in combination with other elements to form the inventors&#39; portable rodent exterminating device, because stun gun technology is well known to those skilled in the art. 
     The use of such a common stun gun as the invention&#39;s ignitor  35  is preferred for multiple reasons, including the high voltage of the spark caused, the low voltage input requirement (typically only a 9-volt battery) and the fact that a stun gun sends an pulsing arc, rather than a singular arc as would be caused by a spark plug. 
     In the present invention, the ignitor  35  has a pair of output terminals  60 ,  62  and a pair of input leads. The output terminals  60 ,  62  each, individually attach to one of the ignition wires  31 ,  31 ′ as discussed supra. The pair of input leads further comprise a positive input lead  64  and a negative input lead  66 . The positive input lead  64  connects to the positive terminal on the battery  37 , and the negative input lead  66  connects to the top terminal  92  on the pressure sensor  32 . A pressure sensor output lead  68  connects the second terminal of the ignition switch  33  to a bottom terminal  96  of the pressure sensor  32  and a battery ground lead  70  connects the first terminal of the ignition switch  33  to the negative terminal of the battery  37 . No connection is made to the middle terminal  94  of the preferred pressure sensor (discussed infra). These connections connect the electrical circuit. 
     When the ignitor  35  is connected in such a manner, the action of depressing or otherwise toggling the ignition switch  33  allows the battery  37  to deliver a charge to the basic electronic circuit in the ignitor  35  which produces brief high voltage pulse which is transmitted through the ignition wires  31 ,  31 ′ resulting in arcing between the two electrodes  36 ,  36 ′ located within the nozzle system  44 , and ignition of the mixture previously delivered to the burrow. However, such charge is only allowed to be delivered to the ignitor  35  when the pressure within the upper barrel  41  drops below the threshold programmed or set within the pressure sensor  32 . 
     The pressure sensor  32  is attached in-line, having a sensor component extending into the upper barrel  41 . Preferably, the pressure sensor  32  opens the electrical circuit it is connected to when greater than 0.03 pounds of pressure exists within the upper barrel  41 . When the pressure within the upper barrel  41  is less than 0.03 pounds of pressure, the pressure sensor  32  closes the electrical circuit. The pressure sensor preferably used is a World Magnetics model 9061-03 PS F103 series sensor. The pressure sensor  32  is an important safety feature, keeping the present invention from igniting the gaseous mixture until after the user has de-actuated the injection trigger or handle  22 . Within a few seconds of de-actuation of the injection handle  22 , the pressure within the upper barrel  41  drops low enough to allow the user  90  to discharge the ignitor  35 . 
     In operation, referring again to FIG. 2, the apparatus is able to be inserted by the user  90  into a burrow passages  10  in the ground (G) through a burrow opening or hole  12 , whereupon the injection trigger  22  is actuated to provide a flow of mixed gas and oxygen into the burrow opening  12  and burrow passages  10 . When the user  90  determines that burrow has been suitably filled with the flammable mixture, the user releases and de-actuates the injection trigger  22 . When a sufficient amount of time, usually 1-2 seconds, has passed for the pressure within the barrel system  40  to drop below the settings on the pressure sensor  32 , the pressure sensor  32  will allow the closing of the ignition circuit, thereby allowing the user to send a current from a battery  37 , to the ignitor  35  by actuation of the ignitor switch  33 , thus resulting in an electrical arc across the electrodes  36  of the ignitor  35 , and igniting the mixture within the burrow  10 . 
     While the above description has been in conjunction with the use of the present apparatus for the extermination of burrowing rodents, such is not intended to imply any limitation of the use for the present apparatus as it may be used, for example, in other applications such as extermination of burrowing reptiles, such a snakes, or the ignition of slash piles of wood. 
     Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the scope of the following claims.