Abstract:
A centralized control unit directs compressed air towards fog generators in different repellant locations to distribute atomized bird repellant. The control unit can contain a timer module that controls the time, duration, and recurrence of the mist pulses to optimize bird repellant use. Multiple bird repellant storage tanks can be placed in each fog generator, or a single, common bird repellant storage tank can be used to deliver bird repellant to each fog generator.

Description:
FIELD OF THE INVENTION  
       [0001]    The field of the invention is bird repellant atomizers. 
       BACKGROUND  
       [0002]    It is known in the art to use chemical bird repellants to ward off animals. Methyl anthranilate, for example, is a naturally occurring GRAS (generally recognized as safe) compound that irritates pain receptors in birds and drives them away. Atomizing a methyl anthranilate composition so that it can be inhaled in mist or fog form increases the efficacy. 
         [0003]    US 2004/0035879 to Vergote teaches a device that atomizes liquid repellants using an air compressor. Vergote, however, is ineffective at distributing a repellant across distances greater than a few meters. If the output of Vergote is increased, the droplets will saturate the air outside the exhaust port, forming larger droplets that will tend to fall to the ground or bind to the surroundings. In order to cover a greater distance, multiple vaporizers must be used. Vergote and all other extrinsic materials discussed herein are incorporated by reference in their entirety. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply. 
         [0004]    US 2007/0141098 and 7334745, both to Crawford, teach a dry bird repellant apparatus that creates a haze using a venturi nozzle, and then blows air into the haze to separate the droplets into a “dry bird repellant.” Since the droplet sizes are smaller, the dry bird repellant can travel greater distances. However, as the output tube is lengthened, the dry bird repellant particles will tend to adhere to the sides of the tube during travel, and the concentration of bird repellant particles will substantially decrease at greater distances. 
         [0005]    Thus, there is still a need for a bird repellant vaporizer that can cover great distances. 
       SUMMARY AND PREFERRED EMBODIMENTS  
       [0006]    The present invention provides apparatus, systems and methods in which a single source of compressed air atomizes repellant in different repellant locations. Each repellant location has a nozzle, preferably a venturi nozzle, which is connected to both the source of compressed air, and a storage tank of liquid repellant. When the compressed air is blown through the nozzle, some of the repellant is drawn up into the nozzle to atomize into the repellant location. 
         [0007]    Preferably, the source of compressed air is an air compressor that maintains a minimum psi pressure, preferably at least 50, 100, 150, or 200 psi. The air pressure can be maintained, for example, by a regulator that activates the air compressor whenever the psi pressure drops below a threshold, and deactivates the air compressor when the psi pressure exceeds that threshold. A gage can be attached to an output line from the air compressor to prevent control a pressure output from the tank. Multiple gages with multiple output lines could be used, for example a high-pressure gage and a low-pressure gage can be used to create a high-pressure source and a low-pressure source, respectively. A typical air compressor includes an electric or other motor, and at least one compressed air tank. 
         [0008]    An airtight seal, preferably a solenoid valve, can be placed along the air passage to control how long and how often compressed air blows through a nozzle. The valve can be normally closed, and only opened when replant needs to be atomized so as not to waste repellant or supersaturate the air by constant atomization. When the system is operating to repel birds, the valve is preferably opened in short pulses over a period of time to create a series of atomizing pulses. 
         [0009]    A timer can be connected to a solenoid valve that can designate how long a pulse lasts, the time in between pulses, and when the pulses should occur. For example, a flip-flop timer could designate a given valve to open every 10 minutes for at most 2 seconds, or could designate a series of valves to open for 5 seconds. A scheduling timer attached to the flip-flop timer could designate a phase of operation to be during daylight. 
         [0010]    A preferred bird repellant is one that has methyl anthranilate, since it is non-toxic yet has been proven to drive birds away. Multiple repellant tanks can be directly attached to the nozzle at each repellant location, away from the air compressor, to prevent the repellant from corroding or damaging the air compressor and the timer. Alternatively, a single repellant tank can be used to supply repellant to multiple nozzles. In a preferred embodiment, a low pressure gage pumps air, preferably no more than 15 or 20 psi, into the repellant tank to push liquid repellant through hoses towards the nozzles. A second solenoid valve can be attached to the hose near each nozzle, and attached to the timer. This way, when the timer opens both valves, the released compressed air vaporize the released repellant in a single pulse. 
         [0011]    Threshold indicators can be used on the repellant tanks to indicate when the volume of repellant in the tank has dropped below a specified threshold. The indicator can set of a warning or an alarm for a user to replace or refill the tank, or can trigger an automatic refill via an automated system. 
         [0012]    A repellant location is the area that is affected by the atomized repellant to repel the desired animal, for example birds. Preferably, the repellant locations do not substantially overlap, so as to cover a maximal area. Each repellant location area of effect can be increased by blowing air through the venturi nozzle at a higher velocity, which not only spreads the fog farther, but also decreases the droplet size. A “fog” is defined herein to mean distributions in which the mean droplet diameter is no more than 20 μm, although preferred fogs have droplet diameter of no more than 10, 8 or even 6 μm. 
         [0013]    Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawings in which like numerals represent like components. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0014]      FIG. 1  is a schematic of a control unit coupled with two fog generators. 
           [0015]      FIG. 2  is a schematic of an alternative control unit with two alternative fog generators. 
           [0016]      FIG. 3  is a map showing the locations of a control unit and a plurality of fog generators. 
       
    
    
     DETAILED DESCRIPTION  
       [0017]    Referring to the drawings to illustrated preferred embodiments, but not for the purpose of limiting the invention,  FIG. 1  illustrates a bird repellant sprinkler system  100  generally includes a control unit  110  and multiple fog generators  150  and  160 . 
         [0018]    Control unit  110  has an air compressor  130 , a pressure regulator  134 , a solenoid valve  112 , and a timer  120 . 
         [0019]    Air compressor  130  typically has a motor  132 , a pressure regulator  134 , and a tank  136 . Pressure regulator  136  is maintains a minimum pressure in tank  136  preferably using a pressure gage connected to an electronic circuit, although other suitable means can be used. One method of maintaining an air pressure is to turn the motor on when the air pressure in the tank drops below a certain threshold, and to turn the motor off when the air pressure in the tank rises above a certain threshold. The threshold to turn the air compressor off can be different than the threshold to turn the air compressor on. For example, if a user prefers the pressure threshold to be between 100-150 psi, the motor of the air compressor can turn off when the pressure rises above 150 psi and turn on when the pressure drops below 150 psi. 
         [0020]    It is contemplated that the air pressure in the air tank can be adjusted as needed. Bird repellant can generally be adequately vaporized using a minimum air pressure of 40 psi. However, since the size of vaporized bird repellant particles can be reduced and the fog dispersion can be increased by increasing the air pressure that is pumped to the nozzles, a higher air pressure is preferred, for example at least 100 psi or 150 psi. 
         [0021]    Compressed air is fed to fog generators  150  and  160  through solenoid valve  112 . Solenoid valve  112  can be any suitable size and can be made of any suitable material to create an airtight seal between air line  140  and air lines  142  and  144  when closed. When opened, the pressurized air from air line  140  escapes into air lines  142  and  144  to create an atomizing pulse at fog generators  150  and  160 . Those skilled in the art will appreciate that the solenoid valve can open a mere gap or can open fully to allow the compressed air to escape. 
         [0022]    Timer  120  has a scheduling timer  122  and a flip-flop timer  124  that controls when solenoid valve  112  opens and closes with control wire  128 . Scheduling timer  122  designates when the system is active according to a set schedule, for example a certain time of day for a 24-hour timer, or the times of days on various weekdays for a weekly timer. If a user wanted to set the system to repel birds during business hours, the user could set the system to turn on during the hours of 8 AM-6 PM on weekdays. Or, if the user wants to prevent the birds from “learning” the system schedule, the user can set the scheduling timer to randomize the activation time of the system. In general, it is considered advantageous to release pulses of fog during daylight and twilight hours, and prevent such release during night time hours. Although, in some situations, such as when protecting the rooftop of an evening ballgame, repelling birds during night time hours is preferred. 
         [0023]    Flip-flop timer  124  controls how long the solenoid valve is opened and closed. In the current embodiment, knob  125  controls how long the solenoid valve remains open in seconds, and knob  126  controls how long the solenoid valve remains closed in minutes. For example, if knob  125  was set to 2 and knob  126  was set to 10, the solenoid valve would remain open for 2 seconds, and then would remain closed for 10 minutes before opening again for 2 seconds. While the current embodiment of flip-flop timer  124  was chosen for simplicity, it is appreciated that alternative flip-flop timer configurations are also suitable. 
         [0024]    Fog generator  150  generally comprises a venturi nozzle  152  and a bird repellant tank  154 . Pressurized air from air line  140  withdraws a small amount of bird repellant from the bird repellant tank  154  and shoots it through venturi nozzle  152  to create bird repellant fog  158 . A tube (not shown) can be inserted into repellant tank  154  to help draw liquid from the bottom of the tank, and a filter (not shown) can be used to prevent larger droplets from escaping. 
         [0025]    Alarm  156  is attached to bird repellant tank  154  to detect the amount of bird repellant left in the tank, and to activate when the level in the tank drops below a certain threshold. Alarm  156  is preferably configured to notify maintenance staff that the volume of bird repellant is low and the tank needs to be replaced or refilled. Alarm  156  can notify maintenance staff using any suitable method, for example a sonic beep, a blinking light, or an electronic signal sent to a central office. Preferably, alarm  156  could even automatically draw bird repellant from a central storage unit and automatically refill the tank. 
         [0026]    Fog generator  160  is identical to fog generator  150 , except fog generator  160  receives pulses of air through air line  144 , and distributes bird repellant fog  168  to a separate repellant location. It is appreciated that while fog generator  160  is identical to fog generator  150  to reduce complexity of the specification, the fog generators can be different from one another. 
         [0027]    It is also appreciated that while solenoid valve is preferably located in control unit  110  as shown, multiple solenoid valves can be attached to an input of the venturi nozzles  152 , with multiple wires running from timer  120  to control each solenoid valve. In such an embodiment, the solenoid valves could be opened simultaneously, one at a time, or any combination thereof. 
         [0028]      FIG. 2  shows an alternative embodiment of a bird repellant sprinkler  200  generally including a control unit  210  coupled with fog generators  250 ,  260 . 
         [0029]    In this embodiment, a single bird repellant tank  220  supplies bird repellant to multiple fog generators  250 ,  260 . Two air lines  140 ,  230  are used to supply high pressure air to fog generators  250 ,  260  and low pressure air to bird repellant tank  220 , respectively. A high pressure gage  212  is coupled to air line  140  to control a high pressure output to air line  146  while a low pressure gage  214  is coupled to air line  230  to control a high pressure output to air line  236 . Pressure gages  212  and  214  can control the pressure output by constricting and expanding a valve. Preferably, high pressure gage  212  restricts the output pressure into air line  146  to a maximum of 150 psi, and low pressure gage  214  restricts the output pressure into air line  236  to a maximum of 15 psi. A person of ordinary skill in the art can appreciate that a variety of pressures can be used without departing from the scope of the invention. 
         [0030]    The low pressure air from air line  236  applies pressure to the bird repellant (not shown) in bird repellant tank  220  to push the liquid into fog lines  240 ,  242 , and  244  and to fog generators  250 ,  260 . This is an advantageous method of using a single air compressor to deliver both compressed air and bird repellant to fog generators located in remote locations and/or high altitudes. 
         [0031]    Bird repellant tank  220  has an alarm  222  similar to alarm  156 , which can notify maintenance staff that the volume of bird repellant is low. Since the current embodiment only has one bird repellant tank, the maintenance staff does not need to check each fog generator to refill the tank. This is ideal when the fog generators are placed in locations that are difficult to maintain, for example the side of a building or the top of a lamp post. 
         [0032]    While control unit  210  is shown as one unit, and is preferably one unit for maintenance purposes, control unit  210  can be divided into multiple units without departing from the scope of the invention. Bird repellant tank  220  can be maintained separately so as not to damage timer  120  or air compressor  130 . Additionally, timer  120  can be placed on an outside of control unit  210  for ease of accessibility. 
         [0033]    Fog generator  250  receives pressurized air from air lines  142  and pressurized bird repellant in fog line  242  which are both fed into venturi nozzle  254 . Valve  252  and valve  256  are controlled by timer  120 , which opens the valves according to a set schedule. When valve  252  and valve  256  are opened, the pressurized air from air line  142  withdraws a small amount of bird repellant from line  146  and vaporizes it through venturi nozzle  254  to create repellant fog  258 . Preferably, all valves are opened and closed simultaneously, but timer  120  can control each valve individually and independently from one another. 
         [0034]    In  FIG. 3 , a bird repellant sprinkler system on building  300  repels birds from repellant locations  322  using control unit  310  and fog generators  320 . 
         [0035]    Control unit  310  remotely activates fog generators  320  from a central location. Each fog generator  320  is capable of generating a fog of bird repellant, generally a composition comprising methyl anthranilate, which covers a repellant location  322 . The shape, size, and volume of repellant locations are dependent on environmental considerations, for example the speed and direction of wind or the orientation of the vaporizing nozzle (not shown). While repellant locations may overlap, minimal overlap is preferred so as to maximize the effective area of the bird repellant. The fog generators  320  can be connected via a wire  310  or remotely. The repellant locations are preferably at least five meters away from each other, and are more preferably at least fifteen or twenty meters away from one another to prevent any overlap whatsoever. 
         [0036]    Separating the fog generators from each other and the control unit by a significant distance reduces the amount of methyl anthranilate residue, which can have a detrimental effect on equipment since methyl anthranilate in its liquid form is relatively caustic. For that same reason, it is preferred that the fog is produced in short vapor pulses to prevent the air from being supersaturated with vaporized repellant, which could coagulate into large droplets that form a residue on the surfaces that contact the droplets. Additionally size of the droplets can be reduced and the fog dispersion can be increased by increasing the air pressure that is pumped to the nozzles. 
         [0037]    Using a single control unit  310  is also advantageous as it significantly reduces the cost of the equipment, since the most expensive components are generally the air compressor and timing mechanisms. Instead of purchasing five air compressors and five timing mechanisms to cover five areas, a single air compressor can be used to deliver fog repellant in five different locations, and a single timer can be used to administer five fog generators. 
         [0038]    Thus, specific embodiments and applications of sprinkling bird repellant fog in multiple areas from a central location have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.