Patent Publication Number: US-6990766-B2

Title: Escape-proof repeating animal trap

Description:
This is a divisional of application Ser. No. 10/196,690 filed Jul. 17, 2002 now U.S. Pat. No. 6,694,669, which in turn is a divisional of application Ser. No. 09/729,832 filed Dec. 6, 2000 now U.S. Pat. No. 6,622,422. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to repeating animal traps, and relates more particularly to an escape-proof animal trap of the inclined plane type adapted to catch and confine a number of targeted animals while automatically resetting itself. 
   Although the concepts of the instant invention are equally applicable to traps for animals of any size, devices of this type are primarily utilized in connection with the trapping of rodents such as mice and rats and, therefore, further discussion herein will be primarily directed to this application. 
   2. Description of the Prior Art 
   Repeating animal traps are well known. The commercial embodiments of such traps currently available comprise a housing defining an enlarged enclosure with one, or perhaps two, inclined plane trap assemblies communicating the interior of the enclosure with the exterior of the housing via an elongated passageway. An inclined plane tilting floor member is positioned in the passageway of each trap assembly and is adapted to lift a door to block an entrance opening when the rodent passes beyond a pivot point thereby limiting escape from the enclosure. When the rodent exits the passageway into the enclosure, the door falls by gravity on the entrance end of the tilting floor to reset the trap and the raised end of the tilting floor limits the ability of a captured rodent to return to the passageway. 
   Captured rodents will attempt to escape in any way possible. Rodents in the enclosure will try to grasp the inner end of the tilting floor to regain access to the passageway. In some instances, rodents on the tilting floor have been able to grasp the side or top edges of the door with their claws or teeth to pull the door down against their own weight, and thereby escape from the trap. 
   Attempts have been made to limit access to the tilting floor and the door by incorporation of various flanges or lips on the trap assembly walls or roof, but such efforts have had limited success. Since the principal purpose of a repeating animal trip is to capture and retain the targeted animals for subsequent disposition by an exterminator or the like, the effectiveness of a trap that permits escape of a captured animal is greatly diminished and a construction that is, for all intents and purposes, escape-proof, would have significant commercial appeal. 
   Another problem associated with repeating animal traps is the tendency of a captured rodent to crawl under, or nest in, the space between the bottom wall of the trap housing and the undersurface of the raised end of the tilting floor when the trap assembly has been reset. The presence of an animal in this location prevents another rodent attempting to enter the trap assembly from tilting the floor and, thereby, being captured. Further, a dead animal in this space effectively destroys the use of the repeating animal trap without extensive maintenance. Provision of means to preclude an animal from entering or nesting in this space would be an obviously desirable feature of a repeating animal trap. 
   It is a well known tendency of mice and rats to stay close to walls in a room, rather than running into the open. If a repeating rodent trap is set against a wall with either or or both of the entrance openings juxtaposed to the wall, the aroma of bait in the housing will generally attract the animal into the trap. However, some rodents will pass by the entrance opening and, thereby, avoid being caught. To some extent, this problem has been minimized by the provision of confining members such as slidable plates secured to the side portion of the housing spaced from the wall to direct rodents that bypass the trap entrance back in the direction of the trap. Yet, some mice or rats will tend to literally climb over the housing to get from one side of the trap to the other without entering the trap. Incorporation of a supplemental trap means to capture a rodent passing over the housing would obviously enhance the effectiveness of the trap. 
   Since repeating animal traps are generally intended for multiple uses, they have been commonly made of sheet metal, such as aluminum sheet or the like, for durability. While some traps made of plastic have been marketed, the ability to produce a repeating animal trap which is virtually escape-proof, with the major components being formed of plastic, would significantly reduce manufacturing costs and enhance versatility. 
   OBJECTS AND SUMMARY OF THE INVENTION 
   It is a primary object of this instant invention to provide a unique repeating animal trap incorporating features that render the same essentially escape-proof. More specifically, according to the instant inventive concepts, means are provided to preclude a captured animal from accessing the inner end of the inclined plane tilting floor to prevent the animal from returning to the trap passageway and means are also provided to preclude an animal on the tilting floor from grasping the top or side edges of the trap door to prevent the animal from unblocking the entrance opening. 
   A further object of this invention is to provide a repeating animal trap including a barrier between the lower surface of the rear end portions of the tilting floor of the trap assembly and the upper surface of the bottom wall of the trap housing to discourage animals from entering or nesting in that space. Consistent with the foregoing, a further desirable object of the instant invention is to also include a mechanism wherein an animal that has entered that space is urged back into the trap enclosure if another animal enters the trap assembly and causes the floor member to tilt about its pivotal support. 
   Another object of this invention is to provide a repeating animal trap of the type described wherein the major components can be formed of plastic in any conventional manner to enable various structural elements to be readily incorporated therein at minimal cost. 
   Yet another object of this invention is the incorporation of means to secure a conventional glue board to the top or cover of the trap so that an animal, attempting to bypass the trap by climbing over the housing, is captured by the glue board. 
   In summary, the repeating animal trap of this invention is extremely simple and inexpensive to manufacture and to maintain and yet, is highly efficient in operation, effectively precluding escape of an animal once it has entered the trap, and, optionally, even capturing animals attempting to bypass the trap by running across the top. 
   Upon further study of the specification and the appended claims, additional objects and advantages of this invention will become apparent to those skilled in the art. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The combination of elements, arrangement of parts and features of construction that lead to the inventive repeating animal trap of the instant invention will be pointed out in more detail hereinafter with respect to the accompanying drawings wherein: 
       FIG. 1  is a fragmentary longitudinal cross-sectional view through an early embodiment of an inclined plane trap assembly in a repeating rodent trap, with the pivotable floor and door members shown in dotted lines in their alternate position; 
       FIG. 2  is a similar view of modified prior art trap assembly; 
       FIG. 3  is a perspective view of an improved escape-proof repeating animal trap according to one embodiment of the instant inventive concepts showing an optional transparent portion of the cover in dotted lines; 
       FIG. 4  is an enlarged end elevational view of the animal trap of  FIG. 3  showing the cover partially lifted in dotted lines for accessing the trap enclosure to bait the same and/or remove animals captured therein for disposal; 
       FIG. 5  is a longitudinal cross-sectional view through the trap assemblies of the repeating animal trap of  FIG. 3 , taken along lines  5 — 5  of  FIG. 4 , with parts being broken away for illustrative clarity and convenience; 
       FIG. 6  is a longitudinal cross-sectional view of one of the trap assemblies of the repeating animal trap of  FIG. 3  showing the pivotable floor and door members in an “open” or reset position providing access to the trap passageway from the exterior of the housing through an entrance opening; 
       FIG. 7  is a view similar to  FIG. 6 , with the floor and door members moved to a “closed” position by the weight of a rodent on the inner end portions of the floor member; 
       FIG. 8  is a perspective view, similar to  FIG. 3 , of a modified embodiment of a repeating animal trap according to the instant invention formed primarily of plastic; 
       FIG. 9  is an enlarged end elevational view of the embodiment of  FIG. 8  showing the cover partially lifted to access the trap enclosure in dotted lines, with a glue board secured to the upper surface of the cover to capture an animal attempting to bypass the trap by climbing over the top; 
       FIG. 10  is a longitudinal cross-sectional view taken along lines  10 — 10  of  FIG. 9 ; 
       FIG. 11  is a longitudinal cross-sectional view illustrating the “open” position of one of the trap assemblies of the repeating animal trap of  FIG. 8 ; 
       FIG. 12  is a view similar to  FIG. 11  with the door and floor member in their “closed” position; and 
       FIG. 13  is a fragmentary perspective view into one of the trap assemblies of the repeating animal trap of  FIG. 8  from the exit end thereof. 
   

   Like parts are designated by like reference characters throughout the several views of the drawings. Alternate positions of the same element shown in dotted lines are designated by the same reference character followed by a prime (′). 
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the drawings, and more particularly to  FIG. 1 , portions of an early prior art repeating animal trap are designated generally by the reference numeral  20  with an inclined plane trap assembly designated generally by the reference numeral  25  there within. 
   A housing  22  includes peripheral walls, a portion of one sidewall being illustrated at  23 , a bottom wall  24 , and an openable cover (not shown) together defining an enlarged enclosure, generally shown at  21 , for retaining one or more captured animals. 
   The inclined plane trap assembly  25  includes sides, one of which is shown at  26  (and may be a portion of the side wall  23  of the housing  22 ), and a roof  27  which, together with a portion of the bottom wall  24  of the housing  22  define an elongated passageway  30 . At one end of the passageway  30  is an entrance opening  32  communicating with the exterior of the housing  22  and, at the other end of the passageway  30 , is an exit opening  34  communicating with a holding chamber  21  defined by the housing  22 . 
   A floor member  40  extends along the length of the passageway  30  intermediate the sides thereof, with first end portions  42  juxtaposed to the entrance opening  32  and opposite second end portions  44  juxtaposed to the exit opening  34 . A pivot element  45  is fixed between the sides of the trap assembly  25  in any conventional manner and underlies and supports the floor member  40  intermediate its end portions  42 ,  44 . A counterweight  46  is secured to the underside of the first end portions  42  of the door member  40  to manually bias the floor member  40  to a first or “open” position, shown in dotted lines in  FIG. 1 , in which the first end portions  42 ′ are lowered and the second end portions  44 ′ are raised. The pivot element  45  is offset toward the first end portions  42  to define a greater lever arm from the second end portions of the floor member  40  so that when an animal, such as the mouse or rat illustrated schematically at  50 , passes the pivot element  45  on its way to the exit opening  34 , the floor member  40  is tilted to a second or “closed” position, shown in solid lines in  FIG. 1 , in which the first end portions  42  are lowered and the second end portions  44  are raised. 
   A door member  60  has bottom edge portions  62  and a top edge  64 . A hinge element  65  pivotally secures the bottom edge portions  62  of the door member  60  adjacent to the entrance opening  32  for movement of the door member  60  between a lowered position, shown in dotted lines in  FIG. 1 , in which the door member  60 ′ tests on the first end portions  42 ′ of the floor member  40 ′ when the floor member  40 ′ is in its first position, to provide access to the passageway by a targeted animal through the entrance opening  32 , and a raised position, shown in solid lines in  FIG. 1 , in which the door member  60  is lifted by movement of the first end portions  42  of the floor member  40  when the floor member  40  is moved from its first position to its second position by the weight of the animal  50  on the second end portions  44  of the floor member  40 . When the door member  60  is in its raised position as shown in solid lines in  FIG. 1  it tends to block any attempt by the animal  50  to return to the entrance opening  32  and, thereby, escape from the trap. 
   It is to be noted that the upper edge  64  of the door member  60  engages the undersurface of the roof  27  of the trap assembly  25  before the door member  60  reaches a vertical orientation. In this manner, the weight of the door member  60  biases the door member  60  about the hinge element  65  toward its lowered position. Thus, when the animal  50  steps from the second end portions  44  of the floor member  40  through the exit opening  34  of the passageway  30  into the holding chamber  21  the counterweight  46  moves the floor member  40  from the second position to the first position, the door member  60  drops onto the first end portions  42  of the floor member  40 , and the trap assembly  25  is automatically reset. 
   A problem with the inclined plane trap assembly  25  of this early embodiment of a repeating animal trap is the ability of a mouse or rat  50  to turn around on the floor member  40  and use its teeth or claws to grasp the top edge  64 , or one of the side edges  66  of the door member  60 , pulling the same against the weight of the rodent on the second end portions of the floor member, thereby moving the door member  60  to its lowered position and unblocking the entrance opening  32 , permitting the animal  50  to escape from the trap. 
   Although the flange  31  overlying the exit opening  34  from the passageway  30  tends to interfere with the ability of a captured mouse or rat within the enclosure  21  from reaching back through the exit opening  34  to grasp the second end portions  44  of the floor member  40  after the trap has reset itself to pull the floor member  40  downwardly to the solid line or second position illustrated in  FIG. 1  permitting the animal  50  to climb back onto the floor member  40  thereby gaining access to the door member  60  to pull the same to its lowered position as discussed above to complete an escape from the trap, this element is inadequate to provide total protection. 
   Referring now to the prior art repeating rodent trap illustrated in  FIG. 2 , wherein parts similar to the embodiment of  FIG. 1  are designated by the same reference character followed by the suffix “a”, the modified trap assembly  25   a  incorporates a downwardly bent lip member  28 , formed from the roof  27 , to limit the position of the raised door member shown in solid lines at  60   a . Inwardly bent flanges, one of which is shown at  29 , are formed in the sides to limit the raised second end portions  44   a ′, shown in dotted lines in  FIG. 2 , of the floor member  48 ′. While assisting in better locating these elements during the capture of a targeted animal  50   a , these modifications have little impact on the ability of an animal to escape from the trap, either while it is on the floor member  40   a  or after it had passed into the holding chamber or enclosure  21   a.    
   Reference is now made to  FIGS. 3–7 , wherein parts similar to the embodiment of  FIGS. 1 and 2  are designated by the same reference character followed by the suffix “b”. A repeating animal trap  20   b  according to one embodiment of the instant inventive concepts is formed of sheet metal in any conventional manner. The overall configuration of a repeating animal trap is better seen in  FIGS. 3–7 , although it should be understood that, except for the specifics of the inclined plane trap assembly portions  25   b  to be discussed in more detail hereinafter, there are no significant changes from repeating animal traps commercially available heretofore. 
   For ease of understanding, the housing in this embodiment is designated generally by the reference numeral  80  and will be seen to include a pair of opposed sidewalls  82 ,  83 , a pair of opposed end walls  84 ,  85 , a bottom wall  86  and cover  88 . Since this is a live animal trap, a plurality of apertures  87  may be defined in the end walls  84 ,  85  to provide an air supply to the holding chamber  92  until the animals are to be removed from the trap  20   b.    
   An optional transparent portion  90  in the cover  88  is illustrated in  FIG. 3  which facilitates viewing the enlarged holding chamber or enclosure  92  defined by the housing  80  to determine status of any bait (not shown) or animals captured therein. The cover  88  may be pivoted at  94  to permit the same to be lifted as shown in dotted lines at  88 ′ in  FIG. 4  to bait the trap  20   b  and/or remove captured animals from within the enclosure  92  for disposal. 
   Opposed apertures  89  are defined in the end walls  84 ,  85  adjacent their respective engagement with one of the side walls  82  and a pair of inclined plane trap assemblies  25   b , modified according to the instant inventive concepts, are provided inside the housing  80 , each trap assembly having its entrance opening  32   b  communicating with one of the apertures  89 . The tendency of a mouse or rat to scurry along a wall enhances the likelihood of capture when the entrance openings  32   b  of the opposed trap assemblies  25   b  are on the same side of the trap  20   b  and are juxtaposed to the wall in an obvious manner. Confining panels (hot shown) may be slidably attached to the opposite side wall  83 , as shown in U.S. Pat. No. 4,103,448, if desired. 
   The principal distinction between the trap assembly  25   b  seen in the embodiment of  FIGS. 3–7 , and the prior art trap assemblies discussed above resides in the configuration of the door member  60   b  and its interrelationship with the lip member  28   b  which extends downwardly from its trailing edge portions  28   b ′ where it connects with the roof  27   b  and has leading edge portions  28   b ″ spaced from the roof  27   b  and the floor member  40   b . First, the door member  60   b  is dimensioned so that the top edge  64   b  thereof is juxtaposed to, and underlies, the undersurface  28   b ″ of the lip member  28   b  when the door member  60   b  is in its raised position as seen particularly in  FIG. 7 . In this fashion, an animal  50   b  on the floor member  40   b  attempting to return to the entrance opening  32   b  is precluded by the overlying leading edge portions  28   b ″ of the lip member  28   b  from engaging the top edge  64   b  of the door member  60   b  in an attempt to escape from the trap  20   b  by pulling the door member  60   b  back to its lowered position and thereby unblock access to the entrance opening  32   b.    
   Additionally, in order to preclude the animal  50   b  from using its teeth or its claws to engage the side edges of the door member  60   b  in an attempt to pull the door member  60   b  to its lowered position, flanges  61  extend from each side edge of the face of the door member  60   b  juxtaposed to the entrance opening  32   b , the flanges  61  being positioned closely adjacent to the sides of the passageway  30   b . The edges  61   b  of the flanges  61  may be angled to facilitate bypassing the lip member  28   b  and resting against the undersurface of the roof  27   b  in the raised position of the door  60   b  as best seen in  FIG. 7 . 
   The foregoing modifications to the door member  60   b  in this embodiment of a repeating animal trap according to this invention, renders the same substantially escape-proof. Even if a captured mouse or rat is able to return to, or turn around on, the floor member  40   b , it simply cannot access any portion of the door member  60   b  to unblock the entrance opening  32   b  and escape from the trap through the aperture  89 . 
   Referring now to  FIGS. 8–13 , wherein parts similar to the earlier embodiments are designated by the same reference character followed by the suffix “c”, a repeating animal trap  20   c  according to another embodiment of the instant inventive concept is primarily formed of an appropriate plastic material in any conventional manner. The selection of the particular plastic material and the manufacturing method used to form the elements is not a critical portion of the instant inventive concepts. 
   In this instance, the housing  80   c  is formed entirely of plastic, including the portions defining the passageway  30   c , only the inclined plane tilting floor member  40   c  and its pivot element  45   c  and the door member  60   c  and its hinge element  65   c , preferably being formed of metal. 
   The ability to form the housing  80   c  of plastic simplifies the manufacturing of the trap  20   c  and enables the incorporation of additional features at minimal cost. For example, it is not necessary to provide a separate roof member, such as the element  27  in the sheet metal embodiments, for the trap assembly  25   c  since the cover  88   c  can perform the same function. Moreover, the downwardly extending lip member  28   c  and the flange  31   c  covering portions of the exit opening  34   c  in the trap assembly  25   c  can be integrally formed with the cover  88   c  in a manner obvious to those with ordinary skill in this art. 
   The basic use and operation of the plastic version of the repeating animal trap  20   c  are similar to the embodiment of  FIGS. 3–7 . However, the trap  20   c  includes several additional features facilitated by the ability to thermoform elements such as the plastic cover  88   c  and the bottom wall  86   c.    
   First, in addition to the transverse flange  31   c  covering portions of the exit opening  32   c  of the trap assembly  25   c , a pair of longitudinal flange members  31   c ′ may be integrally connected thereto extending over, and engaging, the second end portions  44   c  of the floor member  40   c  when the floor member  40   c  is in its first position. Note, particularly,  FIGS. 10 and 11 . In this fashion, the second end portions  44   c  of the floor member  40   c  are further obstructed and less accessible to an animal within the holding chamber or enclosure  92   c  attempting to escape from the trap by pulling the floor member  40   c  to its second position to thereby unblock access to the floor member  40   c  from the enclosure  92   c  and, ultimately, an attempt to engage the door member  60   c  to unblock the exit opening  32   c  from the trap. 
   To minimize the ability of a rodent avoiding capture by running across the top of the repeating animal trap  20   c , the cover  88   c  is provided with a pair of upstanding, inverted L-shaped catches  100 , which may be molded directly into the cover  88   c  and which are adapted to engage and secure edge portions  102  of the base member  104  of a glue board  106 . The upper surface of the base member  104  carries a layer of highly viscous glue or other standard adhesive  108  adapted to trap or capture a mouse or rat trying to run across the top of the cover  88   c  of the trap  20   c . Glue boards are well known and further details regarding the materials used therein, the method and manufacture, or the use of such products is not necessary to enable those with ordinary skill in the art to apply this feature to the repeating animal trap of the instant invention. 
   Since the side of the cover  88   c  used to form the depressed lip members  28   c  is slightly raised, upstanding protuberances such as the “V”s shown at  110  may be formed in other portions of the cover  88   c  to underlie and support the glue board  106  in a level manner. The particular size and shape of the glue board is not an important feature of this invention, and an extended-width glue board  106 ′ is shown in dotted lines in  FIG. 9  to illustrate that the glue board can extend over the entire cover  88   c , if desired. 
   Additionally, a plurality of upstanding posts  112  may be formed in the cover  88   c  to enable a multiplicity of repeating animal traps  20   c  to be stacked, one on another, for storage or transportation. 
   In addition to being able to readily provide a number of improvements in the plastic version  20   c  of the repeating animal trap of this invention by virtue of thermoforming the cover  88   c , the bottom wall  86   c  can easily be provided with a barrier designated generally by the reference numeral  115  to discourage an animal within the enclosure  92   c  from entering or nesting in the space  116  beneath the raised end portion  44   c  of the inclined floor member  40   c  when the floor member is in its reset position as shown, for example, in  FIGS. 10 and 11 . For example, one or a plurality of sharpened projections  118  can be carried by a portion of bottom-wall  86   c  of the housing  80  underlying the end portion  44   c  of the floor member  40   c  of the trap assembly to cause discomfort to an animal attempting to enter the space  116  from the enclosure  92   c  through the exit opening  34   c  of the trap assembly  25   c.    
   Additionally, or alternatively, a portion of the bottom wall  86   c  of the trap housing  80   c  may be used to define a ramp  120  having an upper surface inclined at an angle to the remainder of the bottom wall  86   c  of the housing  80   c  which is substantially the same as the angle of the lower surface of the floor member  40   c  when the floor member  40   c  has been tilted downwardly about the pivot member  45   c  as an animal passes along the floor member  40   c  as seen in  FIG. 12 . The upper surface of the ramp  120  is preferably juxtaposed to, but spaced from, the lower surface of the floor member  40   c  when the floor member is in this position to provide room for the upstanding projections  118 , the height of which substantially fill the spacing between the ramp  120  and the floor member  40   c  as shown in  FIG. 12 . 
   With the inclined ramp  120 , the space  116  is decreased as the floor member  40   c  is moved from the position seen in  FIG. 11  to the position seen in  FIG. 12  by the weight of the animal  50   c  on the floor member  40   c  passing from the entrance opening  32   c  beyond the pivot element  45   c.  In this fashion, an animal nesting or lying dead in the space  116  is urged or pushed toward the exit opening  34   c  and into the enclosure  92   c  when another animal enters the trap assembly  25   c.    
   To reiterate, the use of a plastic housing  80   c  in the embodiment of  FIGS. 8–12  simplifies the manufacture of complex structural elements and reduces the cost of the overall product. While some of the features, such as the inclined ramp and, possibly even the sharpened projections, can be included in the formation of a metal housing for a repeating animal trap, the ability to thermoform the elements of the housing in a trap utilizing plastics is a significant advantage. 
   It will now be seen that there are herein provided repeating animal trap embodiments which are quite versatile in operation, extremely efficient, simple and inexpensive to manufacture and maintain, and which satisfy all of the objects of the instant inventive concepts identified above, and others, including many advantages of great practical utility and commercial importance.