Abstract:
A rodent bait station has a plastic base with a bottom opening which receives a removable bait receptacle which is engaged by two resilient fingers to the base, and secured by a downward projection from the lid, which offers a child-resistant latch, such that the bait receptacle can only be removed for rebaiting by simultaneously deflecting the downward projection and the two fingers while extracting the receptacle.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to rodent bait stations in general and to rodent bait stations for consumer use in particular. 
     Rodenticides can be particularly effective in treating infestations of rodent pests. Bait stations provide an effective mechanism for isolating the rodenticide from children, dogs, other pets, domestic animals, and non-target wildlife. Because the bait associated with the rodenticide can be attractive to non-targeted species, it is desirable to limit access to the rodenticide to dogs, for example, which can devote extended time to gaining entry to a container. Bait stations should not only obstruct the physical entry of the non-targeted species into the station, but also make it difficult for a pet to gain access to the interior by chewing or gnawing on the station. The bait station should also limit the access of children to the bait within. 
     One solution to making rodenticide baits available to consumers is to construct a disposable bait station which does not have provision for re-baiting and incorporates various features which isolate the bait and protect the bait from access by non-targeted species and pets and children, as described in co-pending U.S. application Ser. No. 12/983,725, filed on Jan. 3, 2011, which is incorporated herein by reference. However, in some circumstances where the domestic situation has a high level of or ongoing rodent infestation, it may be desirable to provide the consumer with a re-baitable bait station which still provides all the features which obstruct the physical access of the non-targeted species to the rodenticide bait, make it difficult for pets to gain access to the interior by chewing or gnawing on the station, and make it difficult for children to gain access to the bait. 
     SUMMARY OF THE INVENTION 
     The bait station of this invention is a consumer item, sized either for mice or rats, which may be pre-baited and more particularly which provides for re-baiting. Although incorporating one or more design features in order to make the bait station resistant to pets or people coming into contact with the bait contained within, the bait station also incorporates a removable bait receptacle which, while preserving the various design features described in co-pending U.S. application Ser. No. 12/983,725, filed on Jan. 3, 2011, provides the added functionality of the ability to replace the bait. 
     The bait station is constructed of three injection molded parts: a base part and a cover part which are locked together without provision for opening, and a removable bait receptacle which is removably locked to an opening in the bait station base. The base has a floor and a peripheral wall extending upwardly from the floor, the floor defining an exterior bottom surface. The floor of the bait station has an opening into which the bait station receptacle is received. The bait receptacle is designed to contain and closely surround a bait block. The bait receptacle has a floor surrounded by a receptacle peripheral wall which surrounds the bait on four sides, one side of which is partly cutaway to provide access from the interior of the bait station to a bait block held within the bait receptacle. The bait receptacle floor has a lip which extends beyond the receptacle peripheral wall and overlies the bait station base floor exterior bottom surface. The bait receptacle has resilient latch fingers on either side of the receptacle peripheral wall which engage corresponding surfaces within the bait station to lock the bait receptacle within the bait station. Removal of the bait receptacle is effected by squeezing extensions of the fingers which extend up along the sides of the receptacle and sliding the bait receptacle out of the bait station through the floor exterior bottom surface. 
     The bait station incorporates a key or combination lock consisting of a locking resilient finger which extends downwardly from the center of the cover to engage a flange which extends from one of the resilient fingers on the side of the bait receptacle. The locking finger locks to one of the latching fingers when the latch finger is deflected to release the bait receptacle, thus preventing the bait receptacle from being removed from the bait station. A resilient finger which extends downwardly from the cover is arranged to deflect in a direction which is perpendicular to the deflection direction of the resilient latching fingers on either side of the receptacle peripheral wall. The net effect is that to remove the bait station receptacle fours actions must be taken simultaneously: the locking finger must be deflected away from engagement with the latching finger on the side of the bait receptacle, and both bait receptacle latching fingers must be squeezed toward the bait receptacle at the same time that the bait receptacle is drawn out of the bait station. 
     It is an object of the present invention to provide a bait station which resists being opened by children, dogs, other pets, domestic animals, and non-target wildlife, and yet allows for replacement of the bait. 
     It is a further object of the present invention to provide a re-baitable bait station which better retains the enclosed bait. 
     It is another object of the present invention to provide a bait station which is resistant to a child removing the bait receptacle through a combination lock. 
     It is yet another object of the present invention to provide a rodent bait station which provides for visual inspection of the enclosed rodenticide. 
     Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of the lid of the re-baitable bait station of this invention. 
         FIG. 2  is an isometric view of the lid of  FIG. 1  shown in its relation to a removable bait receptacle, with the bait station base omitted for illustrative purposes. 
         FIG. 3  is a cross-sectional view of an enlarged detail of the engaged lid and bait receptacle of  FIG. 2 , taken along section line  3 - 3 . 
         FIG. 4  is a bottom plan view of the re-baitable bait station of this invention. 
         FIG. 5  is a cross-sectional view of the re-baitable bait station of  FIG. 4  taken along section line  5 - 5 . 
         FIG. 6  is a top perspective view of the re-baitable bait station of  FIG. 4  with the cover removed. 
         FIG. 7  is a cross-sectional view of the bait station of  FIG. 4  taken along section line  7 - 7 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring more particularly to  FIGS. 1-7  wherein like numbers refer to similar parts, a bait station  20  is shown in  FIGS. 1-7 . As shown in  FIG. 7 , the bait station  20  has a base  22  and lid  24 , and a removable bait receptacle  25 . As shown in  FIG. 6 , the base  22  has a floor  26  and an upwardly extending peripheral wall  28 . The lid  24  is locked without provision for opening to the unbroken upper peripheral edge  30  of the wall  28  by six resilient peripheral prongs  32 . A lid central prong  34  also extends to engage the base  22 . As explained more fully in co-pending U.S. application Ser. No. 12/983,725 the prongs  32 ,  34  are terminated by hooks  35  which latch within receptacles  36  formed in the base as shown in  FIGS. 5 and 6 . A central receptacle  38  is supported on a structure  40  which extends upwardly from the floor  26  of the base  22  engages the central prong  34  increasing the overall integrity and rigidity of the bait station  20  to crushing loads preventing the cover from being depressed or bulging out. 
     The upper peripheral edge  30  forms a labyrinth joint  42  between the peripheral wall  28  and the outer edge  44  of the lid  24 . As shown in  FIGS. 6 and 7 , a carport shaped extension  46  extends from the peripheral edge  30  to cover a rodent access opening  48 . The extension  46  creates a narrow passage which is open on both ends, which is attractive to rodents and makes the opening  48  more attractive. When the rodent enters the bait station  20  through the access opening  48 , the peripheral wall  28  and the interior wall  50  direct the rodent along a path  52  shown in  FIG. 6  which leads to a bait block  56  shown in  FIG. 5  contained in the bait receptacle  25 . The circuitous path  52  isolates the bait from the rodent access opening  48 . The bait station base  22  and the lid  24  form a shell with an interior volume and an exterior surface with at least one entry  48  for rodents in the shell exterior surface, and at least one opening in the exterior shell surface into which the bait receptacle  25  can be positioned. 
     The design of the bait receptacle  25  allows removal of the receptacle through an opening  58  in the floor  26  of the base  22 , without compromising the overall integrity of the bait station  20  with its features which resist children and non-target animals, particularly pets such as dogs, from gaining access to the bait positioned within the bait receptacle in the bait station  20 . The bait receptacle  25  is shown in  FIG. 2  as it is positioned with respect to the lid  24 , and in  FIG. 6  the bait receptacle  25  is shown as it is positioned with respect to the bait station base  22  when the bait receptacle is installed and locked within the bait station  20 . 
     As shown in  FIG. 2 , the bait receptacle  25  has a receptacle floor  60  and a receptacle peripheral wall  62  extending upwardly from the receptacle floor to form bait retaining structures. As shown in  FIG. 6 , the peripheral wall defines a long rear wall  66 , a long front wall  68 , and two short side walls  70  which define a rectangular cavity which contains the bait block  56 . The bait block  56  has the general shape of an extruded rectangular prism with additional gnaw edges provided by grooves in the faces of the bait block, such as the ones disclosed in U.S. Pat. No. 5,044,113, the disclosure of which is incorporated by reference herein. As shown in  FIGS. 2 and 7 , rodent access to the bait block  56  is provided by an opening  72  in the front wall  68  of the bait receptacle  25 . The opening  72  is formed as a cutaway of the front wall, leaving a short knee wall  74  which abuts a knee wall  76  forming part of the bait station base  22 . As best shown in  FIGS. 2 and 4 , the bait receptacle  25  floor  60  extends beyond the bait receptacle peripheral wall  62  to form a lip  78 . The lip  78  underlies the exterior bottom surface  80  defined by the base floor  26  as shown in  FIG. 4 , when the removable bait receptacle  25  is installed within the bait station base  22 . As shown in  FIGS. 4 and 5 , the lip  78  is rounded as it comes into engagement with the bottom surface  80  of the base floor  26 . Two small feet  81  extend from the base bottom surface  80  to prevent rocking about the lip  78 . The lip  78  prevents the bait receptacle from being pushed too far into the base  22  of the bait station  20  where it would push against and possibly unseat the lid. 
     Another feature, shown in  FIG. 6 , which performs a similar function comprises four clips  77  which extend from double wall structures  79  on the base  22  which run parallel to the short sides  70 . The clips  77  extend outwardly to overlie the short side walls  70  and extend downwardly on the inside of the short side walls. The four clips  77  prevent movement of the bait receptacle  25  toward the lid  24 , and also hold the short walls  70  of the bait receptacle to the double wall structures  79  of the base. The clips  77  are in part redundant with the lip structure  78  inasmuch as both structures prevent the bait receptacle  25  from being forced against the lid  24 , which forcing against the lid has the possibility that the lid would become detached from the base  22 . As at least partially redundant structures, either one alone can prevent the bait receptacle  25  from being forced against the lid  24 . If both structures are used, the redundant load path resisting movement of the bait receptacle  25  toward the lid  24  means that one or the other structures  78 ,  77  will not be in direct engagement with the base  22 , or the receptacle  25  respectively. Thus the lip  78  may overlie but not directly engage the exterior surface  80 , or the clips  77  may be slightly spaced from the receptacle peripheral wall  62 , however with sufficient force on the floor  26  of the base receptacle, both load paths may become engaged. 
     The bait receptacle  25  is held in place on the base by two resilient fingers comprising a rear resilient finger  82  and a front resilient finger  84  mounted to the rear wall  66  and front wall  68  respectively of the receptacle as shown in  FIG. 5 . The resilient fingers  82 ,  84  extend outwardly down from the upper margin  86  of the bait receptacle, the resilient fingers have hook features  88 , and  90  respectively which are biased by the resiliency of the fingers to engage flange portions  92  and  94  which are integrally formed with the bait station base  22 . The resilient fingers  82 ,  84  are in the locked position when the hook features  88 ,  90  are engaged with the flange portions  92 ,  94 . The resilient fingers  82 ,  84  have lower extensions  96  and  98  which can be grasped with the thumb and forefinger. By squeezing the fingers  82 ,  84  inwardly against the sides  66 ,  68  of the bait receptacle  25  the hook features  88 ,  90  are disengaged from the flange portions  92 ,  94  and thus moved to an unlocked position which unlocks the bait receptacle from the base  22 , and which allows the bait receptacle to be withdrawn through the opening  58  in the floor  26  of the base. 
     The bait station has a locking system which restricts access by a young child to the bait by requiring multiple steps to be performed simultaneously before the receptacle can be separated from the base. Removal of the bait receptacle  25  for the purposes of re-baiting is controlled by a locking or keying mechanism which includes another locking resilient finger  100  which extends downwardly from the lid  24  as shown in  FIG. 1 . The locking finger  100  has a narrow downwardly extending blade  102  cantilevered out from the lid  24  which terminates in a lower triangular prism shaped portion  104 , a portion of which has a series of steps  106  to provide a gripping surface for deflecting the blade  102  which is biased against the front resilient finger  84 , from a locked position engaged with the receptacle front resilient finger, to an unlocked position out of engagement with the receptacle front resilient finger. Another portion of the triangular prism shaped portion  104  forms a smooth ramp  107  to deflect the locking finger  100  when the bait receptacle  25  is inserted into the opening  58  in the floor  26  of the base  22 . A cross-section of the locking system is shown in  FIG. 3 . The locking system prevents withdrawal of the bait receptacle  25  from the base  22  of the bait station  20 . The locking system comprises two parts, a first part  101  formed as an extension of the receptacle front resilient finger  84 , and a second part  103  mounted to the lid locking finger blade  102 . The first part  101  extending from the front resilient finger  84  forms a hook  105 . As shown in  FIG. 1 , the second part  103  extends upwardly from a base surface  108  which extends outwardly and perpendicularly from the blade  102  and which overlies the triangular prism shaped portion  104  as shown in  FIG. 3 . The second part  103  is an L-shaped flange  110  which extends from the blade  102  facing the first part  101 . The L-shaped flange  110  has a longer leg  112  which extends perpendicular to the blade, and a shorter leg  114  which extends a short distance parallel to the blade  102 . The short leg  114  forms a capturing feature which interlocks with a capturable structure formed by the hook  105 . 
     In  FIG. 3  the locking system is shown in the normal locked position so that an attempt to remove the bait receptacle  25  by squeezing extensions  96  and  98  to release the hooks  88 ,  90  causes the front resilient finger  84  to move in the direction of the arrows  116  causing the hook  105  of the first part  101  to capture the second part, i.e., come into engagement with the second part  103  formed by the L-shaped member  110  as shown by the phantom image in  FIG. 3 . When the first and second parts  101 ,  103  are in engagement as caused by an attempt to remove the receptacle  25  by squeezing extensions  96  and  98 , the front resilient finger  84  moves toward the bait receptacle  25  and even allows the hook  90  to disengage from engagement flange  94  on the base  22 , but the base surface  108  prevents the front resilient finger  84 —and the bait receptacle  25  of which the resilient finger is a part—from being slid out of the base  22 . At the same time, the locking finger  100  is prevented from moving in the direction of arrows  118  by the short leg  114  interlocking with the hook  105 . The result is that, not only must the resilient fingers  82 ,  84  be moved by squeezing extensions  96  and  98  toward the sides of the bait receptacle  25 , and the resilient finger  100  be moved in a direction perpendicular to the movement controlling the resilient fingers  82 ,  84 , but a particular order of movement must be observed to place the system in an unlocked position. First the resilient finger  100  must be moved in the direction of arrows  118  and held out of the path of the hook  105 . Then and only then, can the resilient front finger  84  be moved in the direction of arrows  116 , this together with movement of the rear finger  82  on the other side of the bait receptacle  25  in a direction opposed to arrows  116 , releases the bait receptacle from the base  22  of the bait station  20 . The result is a re-baitable bait station  20  which is resistant to non-targeted animals, pets, and small children, while still allowing an adult to remove the bait receptacle  25  and replace the bait block  56 . 
     The base is formed with a downwardly opening recess  120 , as shown in  FIGS. 4 and 7 , which surrounds the lower triangular prism shaped portion  104  of the finger  100 . The recess  120  allows the finger  100  to not protrude from the base and yet still be accessible for actuation. 
     It should be understood that where structure is shown in the drawings or described in the specification the corresponding structure which is described in more detail, for example with respect to structure, function and advantage in the co-pending application Ser. No. 12/983,725 is incorporated herein so as to be applied to the particular similar structure disclosed herein. 
     It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces all such modified forms thereof as come within the scope of the following claims.