Patent Publication Number: US-6655079-B1

Title: Insect bait station

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
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     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
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     COPYRIGHT NOTICE 
     A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyrights. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to devices for use in exterminating pests, and more particularly to a spill resistant insect bait station adapted for refillable containment of a liquid, gel, or granular attractant and/or toxicant for exterminating insect pests. 
     2. Description of the Background Art 
     Human populations have long encountered problems co-existing with various insects, particularly ants. There are more than ten thousand species of ants, a number of which infest structures, lawns, parks, and other areas frequented by humans. The various species of ants vary widely in many respects including size, color, shape, distribution, food preference, and nest locations. A particularly problematic species of ant is the fire ant. Fire ant colonies have become prevalent throughout the southeastern United States and pose a serious problem. The presence of fire ant colonies in lawns, parks, and other areas populated and/or routinely used by humans is a nuisance and a hazard due to the fire ant&#39;s painful sting, coupled with its tendency to attack in numbers. In addition, other species of ants routinely disrupt activities in homes, offices, and parks. As a result, controlling insect populations is therefore necessary. 
     A primary means of pest control involves the use of toxicants, particularly liquid poison. The spraying of liquid poison is a common method of pest control. Spraying liquid poison, however, involves a number of inherent disadvantages. A primary disadvantage involves the risk of exposing humans to the toxic chemical formulations. Furthermore, spraying poison is often harmful to the environment and often causes damage to vegetation and other animal species in addition to the targeted pest population. In addition, liquid poison that has been applied by spraying often degrades over time and/or is washed away by rain or irrigation water thereby reducing effectiveness and requiring repeated treatment and/or the use of greater quantities. 
     For these and other reasons it has been found preferable to contain liquid or gel toxicants in bait stations, which stations provide structures that contain the poison while providing access to insects. 
     The background art reveals a number of attempts directed to pest control. 
     The following patents provide examples of these attempts. 
     
       
         
           
               
               
               
               
               
             
               
                   
                   
               
             
            
               
                   
                 4,648,201 
                 Sherman 
                 5,875,586 
                 Ballard et al. 
               
               
                   
                 4,782,621 
                 Wissman 
                 5,943,816 
                 Hyatt et al. 
               
               
                   
                 4,793,093 
                 Gentile 
                 5,943,817 
                 Miller 
               
               
                   
                 4,823,506 
                 Demarest et al. 
                 5,953,854 
                 Hyatt 
               
               
                   
                 4,841,669 
                 Demarest et al. 
                 5,983,558 
                 Las et al. 
               
               
                   
                 5,446,992 
                 Stewart 
                 6,041,542 
                 Payton et al. 
               
               
                   
                 5,501,033 
                 Wefler 
                 6,189,259 
                 Soller 
               
               
                   
                 5,775,026 
                 Pearce et al. 
                 6,195,933 
                 Woodruff 
               
               
                   
                 5,802,761 
                 Demarest et al. 
                 6,216,384 
                 Dickson et al. 
               
               
                   
                   
               
            
           
         
       
     
     U.S. Pat. No. 4,793,093, issued to Gentile, discloses a feeding station for vermin that allows for ingress of the vermin to feed on poisoned bait held at a central portion therein. The bait is contained within a central well and ingress is facilitated by an inclined ramp leading to the chamber. A cover is joined to the top of the base member to cover the central well holding the poisoned bait. 
     U.S. Pat. Nos. 4,823,506 and 4,841,669, issued to Demarest et al., each disclose an insect bait device for exterminating crawling insects. The devices comprise first and second housing portions joinable to form a housing that defines generally unobstructed entry into the device by an insect. U.S. Pat. No. 5,802,761, also issued to Demarest et al., discloses a bait station including a base defining a bait-cup and a cover fastened to the base. The cover and base cooperate to form a door and walkway to admit targeted insects to enter the bait station thus gaining access to the bait cup. 
     U.S. Pat. No. 5,501,033, issued to Wefler, discloses a liquid delivery bait station having two reservoirs and fluid transfer systems to allow sequential delivery of two liquids. The liquids are preferably an insect attractant that is first delivered into an absorbent feeding pad and an insect toxicant that is next delivered to the absorbent pad. 
     U.S. Pat. No. 5,775,026, issued to Pearce et al., discloses an insect bait station for attracting and killing insects that comprises a substantially flat configuration with insecticide formulated as a solid coating on the surface of a sheet of moisture free material, and one or more breakable ampoules containing an attractant composition. The ampoules are held in a compressible portion of the housing permitting them to be manually broken to discharge their contents on command thereby releasing attractant vapors. 
     U.S. Pat. No. 5,875,586, issued to Ballard et al., discloses a refillable liquid bait station formed to allow access by insects, but not by larger animals. The bait station includes a transparent housing that protects the liquid bait from wind and rain and which further prevents leakage if the bait station is tumbled and/or placed in an incorrect position by use of a series of inner walls and chambers. 
     U.S. Pat. No. 5,943,816, issued to Hyatt et al., discloses an insect bait station for delivering a liquid toxicant. The bait station includes a reservoir, a feeding disk with capillary feeding pores, and a base that seals the feeding pores when configured in a closed position. U.S. Pat. No. 5,953,854, also issued to Hyatt, discloses a spill resistant granular bait station having a tunnel entrance leading to an interior bridged member having an inner wall leading from the bottom surface to an inner surface having an access opening in the bridge member leading to a bait source contained within the station. A cover defines a recessed portion thereon closely cooperating with the access opening in the base. 
     U.S. Pat. No. 6,041,542, issued to Payton et al., discloses a spill-resistant liquid bait station for dispensing liquid bait. The liquid bait is contained in a reservoir at the bottom of the bait station base and a lid is secured over the end of the base. The interior of the bait station is configured for containing the liquid bait if the bait station is inverted. Insects enter the bait station through one or more access ports and then travel through an interior passageway to the liquid bait. 
     U.S. Pat. No. 6,189,259, issued to Soller, discloses an insect bait-and-switch liquid delivery apparatus for the control of insects. The apparatus includes a reservoir defining a first chamber containing a liquid attractant and a second chamber containing a liquid toxicant. A first feeding station is provided in the first chamber and a second feeding station is provided in the second chamber. A passageway connects the first and second chambers, and an access port is disposed to initially prevent or limit access of an insect to the second feeding station during an initial feeding period and the subsequently enable access to the second feeding station via the passageway after the initial feeding period. 
     U.S. Pat. No. 6,195,933, issued to Woodruff, discloses a bait station for delivery of liquid insecticide formed from a base having at least one feeding station and a reservoir for storing liquid beneath the base. The insecticide is transferred by capillary action from the reservoir to the feeding station via a connecting tube. 
     U.S. Pat. No. 6,216,384, issued to Dickson et al., discloses an insect bait station having a continuous outer wall leading from a base to an upper annular surface having a central axial recessed opening therein leading down to a bait source contained in the interior of the station. The interior of the station defines an inverted conical concave part for concentrating the bait to the lowest point of the cone in proximity with an opening in the bottom of the central axial recessed opening. 
     Many of the prior art bait stations are not suitable for use with liquid insecticide and thus possess significant limitations. Those bait stations that claim to be suitable for use with liquid insecticides are burdened with a number of inherent disadvantages, including overly complex and inefficient structures, and generally fail to disclose an effective bait station that is both spill-resistant while remaining easily refillable. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides an insect bait station particularly adapted for use with liquid, gel, or granular insecticides. The insect bait station of the present invention is highly spill resistant and easily refillable, and is effective in both vertical and horizontal configurations. An insect bait station according to the present invention consists of a housing having an open end, a closed end, and a removable end cap assembly adapted for removable engagement with said open end. The housing further includes an internal, axially aligned hollow tubular structure having a first end connected to the housing base in surrounding relation with an axial aperture formed in the base, and a second end aligned for termination coextensive with the open end of the housing. The end cap includes an axially projecting hollow shaft, sized for insertion within the tubular structure. The shaft has a first end connected to the end cap in surrounding relation with an axial aperture formed therein, and a second end adapted for locking inserted engagement with the end plate aperture. The housing interior functions as a reservoir for liquid, gel, or granular bait formulations, such as attractants and toxicants. The axial apertures formed in the housing ends provide insects with access to the interior of the housing through a series of openings defined in the walls of the respective tube and shaft structures. A spiral baffle projects radially outward from the shaft for sealing engagement with the inner wall of the tubular structure to prevent spillage of liquid bait, while defining a passage for insects leading to the liquid bait. A series of offset openings in the shaft and tube walls provide access to the housing interior. Insects enter the bait station through either one of the apertures formed in the housing ends and, by following passages defined within the station, are able to access and hence become exposed to the bait contained therein. 
     Accordingly, it is an object of the present invention to provide an improved insect bait station. 
     Still another object of the present invention is to provide a spill resistant liquid insect bait station. 
     Another object of the present invention is to provide an insect bait station that is not dangerous to children or pets. 
     Yet another object of the present invention is to provide a spill resistant liquid insect bait station that is effective in both horizontal and vertical configurations. 
     Still another object of the present invention is to provide an insect bait station that is easy to assemble, disassemble, and clean. 
     A further object of the present invention is to provide a liquid insect bait station that includes means for guiding insects toward the bait while preventing liquid bait from spilling from the station regardless of the orientation or tumbling of the station. 
    
    
     Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings. 
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 is a rear perspective view of an insect bait station according to the present invention; 
     FIG. 2 is front perspective view thereof; 
     FIG. 3 is an exploded side perspective view thereof; 
     FIG. 4 is an exploded front perspective view thereof; 
     FIG. 5 is a partial side sectional view thereof; 
     FIG. 6 is a partial top sectional view thereof; 
     FIG. 7 is a side perspective view depicting an anchoring spike deployed; and 
     FIG. 8 is a sectional view thereof. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention will further be described with reference to the drawings wherein the same number in the various figures has identical meaning. FIGS. 1-8 depict a preferred embodiment of an insect bait station according to the present invention, generally referenced as  10 , particularly adapted for use with liquid, gel, or granular bait formulations, which formulations may include attractants or toxicants/insecticides. The present invention provides a spill resistant bait station having an internal reservoir for containing bait, such as a liquid toxicant and/or attractant. The bait may further comprise a gel, granular material, or any other suitable form of insecticide. Internal chambers and walls are specifically configured to prevent spillage of liquid bait contained in an internal reservoir while permitting insects to enter the bait station and become exposed to an enclosed insecticide toxicant. Bait station  10  may be fabricated from injection-molded plastic, or any suitable material. 
     In a preferred embodiment, insect bait station  10  includes a housing  12  defining a main interior chamber for containing a liquid or granular bait formulations. In a preferred embodiment, housing  12  is generally cylindrical, however, any suitable shape, whether square, rectangular or any other suitable shape is considered within the scope of the present invention. Housing  12  preferably includes an open end  14 , a closed end formed by an end plate  16 , a base  18 , and a removable end cap assembly, generally referenced as  30 . Base  18  functions to stabilize bait station  10  on an underlying generally planar surface, such as a floor, when in the horizontal orientation depicted in FIG.  1 . Base  18  may define a projecting tab  20  defining an aperture therein for receiving an elongate rigid anchor  22 , such as spike of nail, for anchoring bait station  10  in either a horizontal or vertical configuration. Base  18  further defines an elongate opening  19  therein for removably receiving anchor  22  for storage as best seen in FIG.  1 . As best depicted in FIG. 7, anchor  22  functions to secure bait station  10  at any given location by inserted engagement with tab  20  projecting from housing  12 . Anchor  22  may comprise a metal or plastic spike, threaded fastener, or any suitable anchoring device. 
     As best seen in FIG. 3,  5 ,  6 , housing  12  includes an end cap  30 . End cap assembly  30  is adapted for removable mating engagement with housing open end  14  to form a cylindrical bait station when attached to the housing in the assembled configuration depicted in FIGS. 1,  2 ,  5 , and  6 . Secure attachment of end cap  30  to housing  12  may be facilitated by a tab, referenced as  14 A, projecting from housing open end  14  to for snap-lock engagement with end cap  30 . More particularly end cap  30  includes a lip that engages an outer peripheral edge of end cap  30 . End cap  30  further defines a radially projecting cam  32  on at least a portion of a peripheral edge thereof for urging tab  14 A from a locking position to a release position upon rotation of end cap assembly  30 . In addition, end cap  30  may further include a pair of diametrically opposed projecting tabs  34  for providing grasping members to assist in rotation and removal of end cap  30 . 
     End cap  30  has an external surface defining an axial ingress aperture  36  and a plurality of radial extending recessed channels  38  running from aperture  36  to the peripheral edge of end cap  30 . Recessed channels  38  function to define insect walkways for leading insects to ingress aperture  36 . Similarly end plate  16  defines an axial ingress aperture  26  and a plurality of radially extending recessed channels  28  running from aperture  26  to the peripheral edge of end plate  16 . Recessed channels  26  define tunnel structures leading to ingress aperture  26  when bait station  10  is configured vertically with end plate  16  functioning as a base. Apertures  26  and  36  provide opposing ingress openings leading to the bait-containing interior for insects as more fully discussed herein. 
     Turning now to the internal structure of bait station  10 , housing  12  includes an internal, axially-aligned hollow tube, referenced as  40 , having a first end  40 A connected to housing end plate  16  and a second end  40 B aligned for coextensive termination with the open end of the housing. Tube  40 , and particularly first end  40 A is connected to end plate  16  in surrounding relation with ingress aperture  26  formed in end plate  16 . Similarly second end  40 B of tube  40  is disposed in sealing mating contact with end cap  30  in surrounding relation with a collared axial aperture  36  defined therein when end cap  30  is installed in covering relation with open end  14  of housing  12 . As best depicted in FIGS. 4 and 5, tube  40  further defines a pair of tube wall apertures, referenced as  42 , disposed at a longitudinally intermediate position thereon, thereby placing the intermediate chamber defined by the interior of tube  40  in communication with the main chamber defined within housing  12  external to tube  40 . At least one the tube apertures is preferably disposed at the underside of tube  40  to facilitate drainage of any liquid entering the tube back into the reservoir formed by housing  12 . 
     As depicted in FIGS. 3 and 5, end cap  30  includes an axially projecting shaft  50  sized for insertion within tube  40  as depicted in FIG.  5 . Shaft  50  is substantially hollow so as to define a central chamber within housing  12 . Hollow shaft  50  has a first end  50 A connected to end cap  30  in surrounding relation with aperture  36 , and a second end  50 B adapted for snap locking inserted engagement with end plate aperture  26 . More particularly, shaft second end  50 B defines a pair of projecting members, referenced as  54 , each terminating in a radial lip which bear against the outer surface of end plate  16  in a snap-lock configuration when cap  30  is installed and projecting members  54  are inserted through end plate aperture  26  as seen in FIGS. 5,  6 , and  8 . 
     Shaft  50  further includes a radially outwardly projecting helical flange, referenced as  56 , extending from the outer surface thereof as best seen in FIG.  3 . Helical flange  56  is radially sized for sealing contact with the inner surface of tube  40  when end cap  30  is connected to the open end  14  of housing  12  and shaft  30  is received Within tube  40 . The space between the outer wall of shaft  50  and the inner wall of tube  40  defines an intermediate chamber concentrically disposed relative to said central chamber. Shaft  50  further defines an aperture  58  for providing communication between the hollow interior of shaft  50  and the interior of tube  40  when shaft  50  is inserted within tube  40 . Aperture  58  is disposed longitudinally along shaft  50  and positioned between projecting wall portions of helical flange  58 . Aperture  58  is preferably longitudinally offset from tube apertures  42  to improve spill resistance. 
     As previously noted, housing  12  functions as a reservoir for liquid or gel bait formulations (not shown), such as attractants and toxicants. Removal of end cap  30  provides access to the interior of housing  12  and permits the addition of a bait formulation therein. Removal of end cap  30  is accomplished by simultaneous radial depression of projecting members  54  of shaft  50  lifting of housing tab  14 A and manual separation of end cap  30  from housing  12 . Bait, such as a liquid, gel, or granular toxicant and/or attractant, is deposited within housing  12  external to tube  40 , and end cap  30  is returned to the attached configuration depicted in FIGS. 1,  2 , and  5 . The amount of bait deposited in housing  12  is preferably a volume that results in a fill level that is below the bottom of tube  40  such that bait does not enter tube  40  via lower aperture  42 . 
     As previously noted, bait station  10  may be placed in a horizontal configuration wherein base  18  functions to stabilize cylindrical housing  12 , or in a vertical configuration wherein end plate  16  functions as a base. In either configuration, recessed channels  28  and  38  function as passages for insects. When bait station  10  is disposed vertically with end plate  16  functioning as a base, however, channels  28  define tunnels leading to ingress aperture  26 . Regardless of the configuration, insects drawn to the bait station by the enclosed bait may enter bait station  10  through either ingress apertures  26  or  36 . Upon entering bait station  10  via apertures  26  or  36  insects become exposed to liquid toxicants by passing through the interior of shaft  50  and through aperture  58  into the interior of tube  40 . Upon exiting shaft  50  an insect is free to walk around the circumferential outer surface of shaft  50  confined by opposing walls formed by helical flange  56  until reaching one of the tube apertures  40 . Upon arriving at one of said tube apertures  42  an insect may exit tube  40  through one of said tube apertures  42  thereby gaining access to the toxicant reservoir formed by housing  12 . 
     As noted above, the volume of insecticide placed within housing  12  is such that the insecticide does not enter tube  40  through aperture  42 . Housing  12  may further include an internal circumferential marking corresponding to the maximum fill volume when disposed in a vertical configuration to assist the user in adding the proper amount of insecticide. The maximum fill volume is an amount such that the fill level does not reach the lower portion of tube  40  when bait station  10  is disposed in the horizontal configuration. As should be apparent, the internal structure of housing  12 , tube  40 , and shaft  50  functions to prevent an enclosed bait formulation, such as liquid insecticide, from exiting bait station  10 . More particularly, liquid insecticide contained within housing  12  can only exit bait station  10  by passing through tube apertures  42 , around helical flange  56 , into shaft aperture  58 , and finally down shaft  50  and out one of said apertures  26  or  36 . Accordingly, bait station  10  is highly resistant to spillage. 
     The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious structural and/or functional modifications will occur to a person skilled in the art.