Abstract:
The feed station is a generally rectangular housing forming an enclosure containing a separate bait cup which cooperates with walls of the enclosure to form an inexpensive disposable product. The housing has a pair of initially covered holes which permit the rodent to enter the housing and travel to an opening offset from the holes which provides access to the bait cup. A screen confines bait pellets within the cup, but it is breakable by the rodent. A dispenser on the wall of the housing provides fluid to freshen the bait.

Description:
This invention relates to rodent bait containers, particularly a low-cost, disposable rodent feed station that is safe and convenient in handling and use. 
     The problem of rodent control is never ending. A commonly used method of dealing with heavy infestations of mice or rats is to distribute in the infested area poison or other substance which will cause the rodent to die. The Environmental Protection Agency of the United States Federal Government has considered establishing safety guidelines for the manufacture of rodent bait stations. One of the requirements is that the bait be kept in a tamper-proof box made of material which is impervious to weather and strong enough to prohibit entry by non-target species. Entrance must allow easy access for the target species, but yet prohibit access to bait by larger, non-target species. This can be accomplished by limiting entrance sizes, by using baffles, and/or by incorporating a maze-like construction. Further, the box must have some internal structure containing the bait so that the bait will not be directly exposed to non-target animals from outside the box. 
     Some products are known which generally meet these requirements. U.S. Pat. Nos. 4,228,613, 4,026,064, 3,488,879, and 3,008,262 disclose examples of such products. Most of these devices are relatively expensive or are commercial products used by professional pest control businesses. These devices have the serious disadvantage that the toxic bait must be added by the user when the device is to be used. They are also mostly reusable devices which thus require periodic servicing to replenish the bait. While this is not an exceptionally difficult task for trained personnel, it is an unpleasant and somewhat dangerous chore for non-professionals, such as a homeowner or other individual having a pest control problem but not having sufficiently severe problems to justify the expense of employing a professional. The task of servicing a rodent bait station must be done with care and with adequate safety precautions in view of the toxic nature of the bait which is normally employed. Thus, a need exists for a rodent bait station which will meet governmental safety regulations and can be purchased and used with safety by an ordinary consumer. The device must of course be effective in eliminating the target species and it must be simple to use and sufficiently inexpensive to be practically disposable so as to eliminate handling of toxic bait materials. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a bait feed station is provided which includes a bait cup preferably made of plastic which simply fits within grooves or recesses formed within walls of an inexpensive plastic housing having an upper wall and a plurality of depending side walls. The housing is then closed by a flat sheet which forms the bottom wall and holds the bait cup in proper position within the housing recesses. 
     The housing has one or more holes for access to the interior of the housing by target species, such holes being initially closed by readily movable but tamper-proof doors. The bait cup is provided with an opening for access by the rodent to the bait, such opening being offset with respect to an entry hole in the housing wall so that a child or pet cannot easily have access to the bait. The opening to the bait cup is preferably covered by a screen which is strong enough to confine solid bait positioned within the bait cup, but is made of material which can be easily chewed away or broken by the rodent. This ensures that the bait cannot fall or be shaken out of the package before it is intended to be used. 
     Preferably, the bait cup is provided with portions which help position the cup in the housing and which form barriers leading to the bait cup opening. The barriers further limit the possibility of bait escaping out of the housing, while the rodent can simply climb over the barrier to reach the bait cup entry. 
     As another feature of the invention, a fluid dispenser is mounted in the housing wall above the bait cup so that when the bait station is to be used, fluid may be dispensed onto the bait to freshen it. A suitable fluid can be applied to the bait which will react with the bait to make it more attractive to the rodent, or the fluid itself may attract the rodent. 
     Thus, the invention provides an inexpensive yet reliable product that satisfies safety regulations. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the exterior of the rodent feed station of the invention; 
     FIG. 2 is an enlarged perspective view of the feed station with the housing partially cut away to illustrate the interior and with the entrance hole covers spaced away from the main structure to illustrate the path that a rodent follows to reach his bait; 
     FIG. 3 is an exploded perspective view illustrating all the components of the feed station; 
     FIG. 4 is a fragmentary view illustrating the shape of the rodent entry hole; 
     FIG. 5 is an elevational view showing detail of the door for the rodent entrance hole; and 
     FIG. 6 is a perspective view of an alternative form of bait cup having additional struts and baffle elements for preventing bait from escaping from the feed station. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1, 2 and 3, the rodent feed station may be seen to include a main housing 10 having a generally flat, horizontal upper wall 12 with a plurality of depending side walls forming a generally rectangular cross-section including spaced, generally parallel walls 14 and 16 joined by spaced walls 18 and 20. At the bottom or lower edge of the side walls is a first outwardly extending flange 22, a short vertical wall 23 and a second peripheral flange 24. The housing 10 is preferably formed as a one-piece unit of light-weight, semi-rigid plastic such as high impact polystyrene. With such material, the housing can be inexpensively manufactured by vacuum forming, the side walls being slightly tilted from vertical to facilitate this forming process. 
     The housing flange 22 and vertical wall 23 form a recess 26 sized to mate with a flat plastic sheet 28 which becomes the bottom wall of the enclosure formed. The sheet 28 is flush with the flange 24, and it is preferably sonically welded in place so that it is impossible to remove the sheet without major force and tools. This prevents the possibility of inadvertent or improper access to the interior of the housing. 
     The housing wall 18 is generally flat except that it includes a central section 18a which extends outwardly beyond the face of the remainder of the wall, with the outwardly formed recess extending from the bottom to the top of the wall. Referring to FIG. 2, the opposite wall 20 includes an outwardly extending recess 20a which extends about the same wall width as the recess 18a; however, the recess 20a extends only from the bottom sheet 28 a short distance. 
     Positioned within the housing 10 is a bait cup 30 having a pair of spaced, parallel vertical walls 32 and 34 which are joined at the lower end by a partial wall 36 and joined at one edge by a vertical wall 38. The forward edges of the vertical walls 32 and 34 fit within the edges of the recess 18a. These vertical walls also include extension portions 32a and 34 which extend across the width of the housing 12 and the outer ends of the extensions fit within the edges of the recess 20a. Thus, the recesses 18a and 20a essentially position the bait cup 30 within the housing and form a bait compartment, without any need for fasteners, etc. The vertical walls 32 and 34 extend to the upper wall 12 of the housing so that there is no access to the interior of the bait cup through these walls. The rear wall 38 includes a large central opening such that the wall is more in the nature of a frame. This opening is covered by a screen or net 42, which is secured to the wall 38. This screen is preferably an integral part of the bait cup and is injection-molded as one unit. This minimizes product costs and has greater likelihood of being defect free. A quantity of bait 44 is positioned in the bait cup 30. 
     The housing walls 14 and 16 are each provided with an opening 46 which forms a doorway for rodents to enter the trap housing. These openings are axially aligned with each other, and one faces the bait cup wall 32 while the other faces the bait cup wall 34. These openings are initially closed by removable safety plugs or doors 48. As may be seen, each opening 46 includes a pair of diametrically-spaced recesses 46a, as well as a flat chord-like portion having a small notch 50 formed in that portion. The safety doors 48 are disc-like but include an inner portion 48a of one diameter having a pair of diametrically opposed, outwardly extending locking tabs 48b. This inner portion 48a is sized to just fit within the housing wall opening 46 while the tabs 48b fit within the recesses 46a of the opening. 
     Each of the doors further includes an outer portion 48c which has a diameter larger than the inner portion and larger than the hole 46 in the housing. This outer portion includes a pair of recesses 48d which are aligned with the tabs 48b on the inner portion 48a. One of these recesses includes an outwardly extending protuberance 48e. There is little or no axial gap between the tabs 48b of the inner portion and the outer flange on the outer portion 48c. The outer portion includes a slot 52 for receiving a coin or a screwdriver, with the slot being aligned with the tabs 48b of the inner portion. 
     When the plug is installed in the opening, the tabs 48b are aligned with the recesses 46a of the opening 46 as shown in FIG. 2, and the plug is then rotated 90° by inserting a coin or a screwdriver into the outer slot 52. During this rotation, there is frictional engagement between the tabs 48b of the inner door portion and the outer flange of the outer door portion 48c with the thin housing wall 14 or 16. When the door is rotated 90°, the protuberance 48e on the outer portion snaps into the recess 50 of the door opening, thus locking the door in the opening. Provision is made (see FIG. 2) for these doors once removed to be stored alongside the mouse entry holes by snap fitting a button 51 on the door into a small hole 53. Thus if the mouse is stopped, the consumer may reclose the bait station or reinstate total closure prior to reuse. 
     The upper wall 12 of the housing is formed with a small dispenser 54 which contains a liquid for moistening the bait 44 in the bait cup 30. This dispenser, as shown in FIG. 3, includes a pair of mating, shallow, cup-like resilient members which are clamped together by a ring 55 to form a small chamber in which the attractant is positioned. This dispenser is positioned in a recess 56 in the upper wall 12 of the housing. A small opening (not shown) is formed in the bottom wall of the dispenser so that fluid may be dispensed by depressing the upper wall 54. 
     Also formed in the upper wall 12 are a pair of windows 60 for viewing the bait cup wall 38 near the central part of the housing. 
     When the feed station is to be used, the doors 48 are removed from the pair of openings in the housing, and stored adjacent to the openings, the upper wall of the dispenser 54 is depressed a few times causing attractant to drip onto the bait 44 in the bait cup 30, and the feed station is then positioned in an area the rodents have been frequenting. When a mouse or other rodent approaches the housing, it can smell the bait but cannot actually reach it without entering the housing. To reach the bait, the rodent must follow the path indicated by the arrows in FIG. 2. After the rodent enters one of the openings 46, it must step over the bait cup wall extension 34a to reach the window leading to the bait. The net 42 covering the window can be chewed away by the rodent, thus allowing the rodent to reach the poison bait 44. The bait will preferably include a slow killing anti-coagulant. Thus the rodent will always leave the housing before dying, so that a large number of rodents may be poisoned by the single feed station. 
     It should be noted that the rodent cannot reach the bait until the netting is chewed away; thus, the bait cannot escape until the feed station is to be used. If some of the bait should then fall out of the bait cup, the bait is still confined by the extensions 32a and 34a of the bait cup walls. Further, if bait should somehow get over these wall extensions, it still cannot easily get out of the trap in that the hole 46 through which the rodent enters the housing is also spaced upward slightly from the bottom wall 24 so that a lip is formed to restrict bait from being removed from the feed station. 
     After the feed station has been in position for a few days, it can be inspected and the quantity of bait remaining checked by looking through the viewing windows. If bait still remains, it may be freshened by depressing the attractant dispenser a few times. Once the bait is all consumed, it is intended that the entire feed station be discarded since it is relatively inexpensive. However, when all mouse activity ceases, the feed station can be reclosed with stored doors and either saved or reused. With either approach, the user never has to touch the bait, and there is no bulk supply of bait elsewhere presenting a hazard. Typically, bulk supplies are in a cardboard box that must be carefully stored to prevent a hazard. 
     FIG. 6 illustrates an alternative form of bait cup 130 which may be employed instead of the bait cup 30 illustrated in FIGS. 2 and 3. The bait cup 130 is similar to cup 30 in that it has side walls 134, a bottom wall 136 and a front wall 138 having a window covered by a breakable netting 142. The side walls 134 also have extensions 134a that extend to the opposite wall of the housing. However, for additional strength, these extensions include bottom wall portions 134b that create an angled cross section. In addition, a pair of prong-like elements 144 extend from the front wall 138 of the bait cup essentially parallel to and spaced from the extensions 134a, as may be seen from FIG. 6. 
     The bait cup 134 is further provided with a pair of struts or wings 146 that extend laterally outwardly from the side walls 134, approximately aligned with the front wall 138. As may be seen, these wings have an angled or L-shaped cross section formed by a vertical portion 146a which engages the bottom wall of the housing, and a horizontal portion 146b attached to the upper end of the vertical portion and extending in the direction of the path to the access window of the bait cup. 
     The primary purpose for the prongs 144, as well as the wings 146 is to minimize the possibility of bait from escaping from the feed station. When a mouse chews away the netting covering the window, some of the dry bait pellets are likely to fall out of the bait cup. There is then some possibility that a mouse may kick or carry some pellets away from the window area. The prongs 144 form short vertical barriers to prevent the bait pellets from being moved away. Additionally, if the pellets escape the area between the two prongs 144, they may then be blocked by the side wall extensions 134a. Finally, if some pellets should get carried or kicked over the side wall extensions 134a, they are further restricted by the wings 146. Also, the upper horizontal portion 146b of the wings makes it particularly difficult for bait pellets to get over the wings and actually reach the outlets from the bait station. Thus, there is a series of barriers to help contain the bait within the feed station. The wings 146 further serve to strengthen the bait cup structure and help position it laterally within the surrounding housing. It should also be noted that the bait cup with the additional elements shown can still be molded as a single unit to thus keep the cost of manufacture to a minimum.