Abstract:
An electric or electronic animal trap with a CPU-controlled, rearming, multiple killing plate configuration and automatically resetting interruptible beam sensor for triggering a high voltage cycle. A high-voltage output circuit is connected to killing plates which are activated with a high-voltage pulse train when a pest interrupts the beam signal, such as an infrared beam signal generated by an infrared transmitter to an infrared receiver. The trap is preferably configured to automatically rearm if the IR beam signal is no longer interrupted after the killing cycle. If the IR beam signal is still blocked after the killing cycle, however, the trap enters a standby mode indicating trap servicing is required to remove the dead rodent from the trap.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to electric or electronic animal traps, and relates more particularly to an animal trap adapted to catch and electrocute a targeted animal, and also to rearm in the event the continuing presence of the animal is not detected upon completion of a killing cycle. 
         [0003]    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 and killing of rats and the description will, therefore, focus on this application. 
         [0004]    2. Description of the Related Art 
         [0005]    A number of animal traps have been developed which include structural devices to trap an animal and prevent its escape, along with electric or electronic components which act to kill the trapped animal. 
         [0006]    One such device is found in U.S. Pat. No. 6,609,328 (“the &#39;328 patent”, which is hereby expressly incorporated herein by reference as if fully set forth in its entirety. The trap disclosed in the &#39;326 patent electrocutes the animal while also providing a visual indicator signaling when the trap has initiated a kill cycle and thereafter requires servicing to remove an electrocuted animal. 
         [0007]    Other trap designs that have relied upon electrocution and effectively prevented pest-escape in the prior art are set forth in U.S. Pat. No. 6,735,899 (“the &#39;899 patent”), which is hereby expressly incorporated herein by reference as if fully set forth in its entirety. The electronic traps disclosed in the &#39;899 patent utilize at least two fixed barriers or diverter members that are positioned between the opening of the trap and a pair of spaced charge plates electrically connected to a voltage source. The barriers reduce the risk of escape so that, when the trap enters the standby mode after trap activation through contact of the pest with the pair of plates, the trap is more likely to have been effective in killing and retaining the dead pest. 
         [0008]    Even with the structures intended to prevent escape, larger vermin such as rats may not have been killed and may have escaped. As a result, since the standby mode indicates the presence of a dead pest, because it was in fact initiated by a false trigger, wasted effort is expended by exterminator personnel or other users in servicing and resetting a trap which is, in fact, already empty. 
         [0009]    Hence, a trap having three killing plates for greater killing power has been developed as described in U.S. Pat. No. 7,219,466 (“the &#39;466 patent”), also assigned to the present assignee. The disclosure of the &#39;466 patent is also hereby expressly incorporated by reference as if fully set forth herein in its entirety. The trap disclosed in the &#39;466 patent application electrocutes the animal by activating a pair of spaced killing plates, with the first plate being electrically coupled to a third plate that is brought to the voltage level of the first plate approximately 1 msec after circuit activation. The killing circuit is activated when a pest of known impedance is sensed across the pair of plates. The use of three plates both increases electrocution capability and decreases the likelihood of pest escape once the trap has been activated. 
         [0010]    The trap of the &#39;466 patent also uses the sensing of a known impedance across the pair of plates after the killing cycle to determine whether the pest is still present and, in the absence thereof, automatically rearms itself without requiring human intervention. If a dead rat is present, however, the trap enters the standby mode and provides a visual indicator that trap servicing is required. 
         [0011]    Because the &#39;466 patent relies upon detecting impedance across the plates within a range which is representative of a rat, the trap may not detect undesired pests which fall outside this range. Further, if the rat is present but is not in contact with both plates, as when the animal sits up on its haunches to investigate the roof area of the trap, its presence will not be detected. Since detection of a resistance value across the plates is also used after trap activation to determine whether or not to automatically reset, should there be any failure to detect a killed rodent due to the rat&#39;s positioning after death, i.e., the rat&#39;s body is not in solid contact with one of the plates, the trap would nonetheless reset. This would be undesirable because rats are known to avoid other dead rats so that the trap would be ineffective in capturing a second rat. In addition, the trap could “hide” the dead carcass for an extended period, exposing the surrounding area to the resulting decay and bacteria growth, since the trap would not provide the visual indicator that a dead animal is contained therein and trap service is required. 
         [0012]    Therefore, a need exists for a trap that combines an electronic circuit having high voltage to provide killing power effective to terminate rats, with a detection mechanism that is able to detect the presence of any pest. Preferably, the trap will also rearm the trap without human intervention in the event of pest escape. 
       SUMMARY OF THE INVENTION 
       [0013]    In view of the foregoing, it is one object of the present invention to overcome difficulties in prior art traps due to false-positive indications from an electronically-controlled animal trap. 
         [0014]    Another object of the present invention is to provide an electronic animal trap having a plurality of killing plates spaced from one another and activated by the target animal&#39;s presence interrupting an interruptible beam signal, such as an infrared (IR), motion sensor or photocell beam signal. The trap is capable of automatic rearming whether or not the animal is dispatched. 
         [0015]    A further object of the present invention is to provide an electronically-controlled animal trap that is able to detect the absence of an animal and thereafter to rearm itself multiple times without requiring human intervention. 
         [0016]    Yet another object of the present invention is to provide an electronically-controlled animal trap having a detection mechanism that generates and senses an interruptible beam signal, i.e., an interruptible beam sensor. The interruptible beam sensor is effective against any incoming pest large enough to interrupt the interruptible beam signal. 
         [0017]    A still further object of the present invention is to provide an electronically-controlled animal trap, particularly a rat trap, which will quickly and efficiently electrocute a targeted animal, is simple in construction, inexpensive to manufacture and highly reliable and completely safe in use, with reduced servicing requirements through automatic rearming and interruptible beam sensing. 
         [0018]    In accordance with the foregoing objects, the present invention is directed to an electronic animal trap having a housing with a plurality of killing plates spaced from another on the floor of the housing. The trap includes a micro-controller chip with a high voltage circuit for generating and delivering a high-voltage pulse train to the killing plates for an extended killing cycle. The circuit is activated when the body of the rat interrupts an interruptible beam signal transmitted by a beam transmitter on one side of the trap to a beam receiver on the opposite side of the trap to initiate the killing cycle. If, upon conclusion of the killing cycle, the interruptible beam signal remains interrupted, i.e., the beam receiver does not detect the beam signal, the circuit activates a visual indicator to alert a user that the trap contains a dead rodent. If, on the other hand, the interruptible beam signal is detected by the beam receiver, likely meaning the animal has escaped, the circuit automatically rearms itself and no visual indicator is initiated. 
         [0019]    As used herein, the term “interruptible beam sensor” means a detection mechanism that generates and senses an interruptible beam signal. The interruptible beam sensor increases the likelihood of rapid and reliable pest detection, both before and after the killing cycle. 
         [0020]    Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    The combination of elements, arrangement of parts and features of construction that lead to the rearming animal trap with three-killing-plate configuration of the instant invention will be pointed out in more detail hereinafter with respect to the accompanying drawings in which like parts are designated by like reference characters throughout the several views of the drawings. 
           [0022]      FIG. 1  a block diagram of the high-voltage, rearming circuitry with three-killing-plate configuration and interruptible beam sensor, in the form of an infrared (IR) sensor, according to the present invention. 
           [0023]      FIG. 2  is a front perspective view of an embodiment of an electronic animal trap that may be used with the high-voltage rearming circuitry of  FIG. 1  according to the present invention. 
           [0024]      FIG. 3  is another front perspective view of the animal trap embodiment of  FIG. 2 . 
           [0025]      FIG. 4  is a side view of the animal trap embodiment of  FIG. 2 . 
           [0026]      FIG. 5  is a view from the entrance end of the animal trap of  FIG. 2 . 
           [0027]      FIG. 6  is a transparent rear perspective view of the animal trap embodiment of  FIG. 2 . 
           [0028]      FIG. 7  is a flow chart of a high-voltage rearming electronic circuit according to the present invention. 
           [0029]      FIG. 8  is a schematic illustration of the high-voltage rearming electronic circuit with IR sensor and three-killing-plate configuration of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0030]    Although only one preferred embodiment of the invention is explained in detail, it is to be understood that the embodiment is given by way of illustration only. It is not intended that the invention be limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. Also, in describing the preferred embodiments, specific terminology will be resorted to for the sake of clarity. It is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. 
         [0031]      FIG. 1  is a block diagram of the rearming circuit components, generally designated by the reference numeral  100 , according to the present invention. The circuit components  100  include a high-voltage output circuit  10  controlled by a central processing unit (CPU)  12  and electrically connected to a power supply  14 . The CPU  12  may be embodied as a standard 8-bit micro controller chip, and the high output circuit  10  can be a standard fly-back circuit. 
         [0032]    A first electrical connection member  16 , which may be embodied as a wire, receives current from the high-voltage output circuit  10  and also connects to a first killing plate  18  so that electricity can be provided thereto. A second electrical connection member  20 , which may also be a wire, connects the high-voltage output circuit  10  to a second killing plate  22 . The first and second killing plates  18 ,  22  are the plates which are activated when the circuit is triggered. According to a preferred embodiment, a third killing plate  24  is coupled to the first plate  18  by a third electrical connection member  17  and automatically goes to the voltage level of the first plate  18  when the circuit is activated. The circuit is turned on to an enabled state by a switch  26  accessible from the exterior of the trap and adjacent an LED  28  which provides the user with visual indicators of trap operating status. 
         [0033]    According to a preferred embodiment, the circuit  10  receives input from an IR sensor  32  mounted inside the trap. For ease of discussion hereinafter, the IR sensor embodiment will be referred to but this is understood to be representative only. Any interruptible beam sensor having comparable functional capabilities could be used in place thereof without departing from the intended scope of the present invention. Other examples include, but are not limited to, interruptible photocell beam sensors, motion sensors, reflective sensors, and the like. 
         [0034]    The IR sensor includes an IR transmitter  50  and an IR receiver  52  (see  FIG. 5 ) mounted on opposite sides of the trap that transmit and receive an IR beam signal, respectively, from one side of the trap to the other. The circuit is activated to initiate a high voltage killing cycle when the beam signal is interrupted by the body of an incoming rodent. A full schematic representation of the circuit components  100  is provided in  FIG. 8  and will be discussed more fully hereinafter. 
         [0035]    Before describing the structure and operation of the rearming circuit components  100  of the present invention in detail, a representative trap embodiment within which the circuitry may be incorporated will be explained in order to provide the necessary backdrop for a full understanding of the present invention. 
         [0036]      FIGS. 2 and 3  depict two perspective views of an electronic animal trap, generally designated by the reference numeral  200 , which is suitable for use with the high-voltage, rearming circuitry of the present invention. Side and end views of the trap are set forth in  FIGS. 4 and 5 , respectively, and  FIG. 6  is a transparent rear perspective view. 
         [0037]    As shown, the housing  30  has a bottom wall  32 , two upstanding side walls  34 , and a roof  36  provided with an electronics chamber  38  and a power supply cover  40 . The upper surface of the electronics chamber  38  carries the switch  26  or button that toggles from an “on” or standby position, in which the circuit may be activated, to an “off” or reset position, and the LED  28 . 
         [0038]    The LED  28  is mounted on the upper surface of the electronics chamber  38  to provide visual indications of the activity and status of the trap. The LED  28  turns “on” or flashes to provide a visual indication to the user during activation of the trap and thereafter when the trap contains a dead rat as will be more fully described hereinafter. Additional LEDs may also be included should separate indicators of differing colors be desired. 
         [0039]    The power supply cover  40  covers an area which contains the power supply  14 . Of course, the assembly may be simplified by using a single cover portion for the electronics chamber and the power supply. The high-voltage output circuitry of the present invention may also be incorporated within any of the embodiments shown in the &#39;899 patent, and the present application is intended to cover all such embodiments. 
         [0040]    With reference to  FIGS. 2 and 3 , the bottom wall or base  32 , side walls  34 , back wall  42 , front overhang  44 , and roof  36  together define an enclosure or killing chamber for the targeted animal. The side walls  34  define the elongated passageway leading toward the back wall  42  from the entrance opening  46  which communicates with the exterior of the housing  30 . 
         [0041]    The power supply  14  which provides power to the trap preferably includes one or more batteries, such as two AA batteries. Alternatively, the trap may be electrically connected to a wall outlet. When embodied as a battery, the power supply  14  may be conveniently located in the power supply area under the power supply cover  40 . The cover  40  is preferably snap fitted for easy entry to replace expired batteries. 
         [0042]    In use, the high-voltage output circuit  10  is electrically connected to the power supply  14  to convert the power to electricity. The first electrical connection member  16  receives the electricity from the high-voltage output circuit  10  and also connects to the first plate  18  near the back wall  42  so that electricity can be provided thereto. The second electrical connection member  20  connects to the second plate  22  in the middle of the trap to provide electricity to the second plate  22 , while the third plate  24  at the entrance  46  to the trap is coupled to the first plate by the third electrical connection member  17 . 
         [0043]    As shown, the first, second and third plates  18 ,  22 ,  24  are immediately adjacent to one another in spaced relationship, with the first plate adjacent the back of the trap, the third plate adjacent the front of the trap, and the second plate in the middle. While the plates are shown to be of different sizes, plates of the same size or any combination of plate sizes for the three plates is intended to fall within the scope of the present invention. 
         [0044]    As shown in  FIG. 4 , the height of the trap preferably decreases gradually from the entrance  46  to the back wall  42 . In one preferred embodiment, the trap height begins at approximately 4 19/32″ and declines to a height of about 4¼″. This decreasing height provides a more inviting approach from a rodent&#39;s perspective and also reduces the amount of space available for evasive action once inside the trap. The width of the trap may also decrease from the entrance  46  to the back wall  42 , again attracting rodents who prefer close spaces while limiting their maneuverability. In one preferred embodiment, the overall length of the trap is approximately 8½″ with a width at the base of the entrance  46  of just under 4″. 
         [0045]    As shown in  FIG. 5 , the back wall  42  is provided with openings  48  which allow the smell of the bait to permeate the area around the trap, while also allowing the rodent to sample the bait without entering the trap. This increases the interest of the rodent, providing positive reinforcement so as to overcome their natural tentativeness, particularly in the case of rats, concerning new places. As the confidence of the pest increases, and with the improved visibility into the trap provided by light entering the openings  48 , it becomes increasingly likely that the rodent will enter the trap in order to obtain a larger portion of the bait contained therein. 
         [0046]    As shown in  FIGS. 5 and 6 , the IR transmitter  50  and IR receiver  52  of the IR sensor  32  are mounted on or adjacent the side walls  34  so as to face one another across the width of the trap. According to one preferred embodiment, the IR sensor  32  is mounted on a bracket generally designated by the reference numeral  54  which is affixed to or molded integrally with the housing  30 . The bracket  54  has an inner frame component  56  and an outer frame component  58  joined by a bridge element  60  that together define a channel, generally designated by the reference numeral  62 . The IR transmitter  50  and receiver  52  are secured to the bridge element  60  within the channel  62  so as to be supported and protected on each side by the frame components  56 ,  58 . The bracket is positioned between the first and second killing plates  18 ,  22  so as to be nearer the back wall  42  than the entrance opening  46 . This ensures that the rat is fully within the trap before encountering the IR beam and causing the high voltage pulse train to be initiated. 
         [0047]    The IR transmitter is preferably embodied as an IR emitting diode while the IR receiver is preferably embodied as an IR photo transistor such as a 3DUll pin diode with preamp. According to a preferred embodiment, the IR transmitter  50  emits an IR beam for 50 msec every second. In the absence of a rodent, the IR receiver  52  regularly and repetitively receives the IR beam signals at the rate of emission. If, however, the IR beam signal is blocked so that the IR receiver  52  does not receive the beam signal for a threshold time period, the electrical circuit is activated. According to a preferred embodiment, electrical circuit activation is triggered when the IR receiver  52  does not receive two consecutive IR beam signals, resulting in a threshold time period of about 1.5 seconds. However, shorter or longer thresholds may be established during trap design and manufacture as would be understood by persons of ordinary skill in the art. 
         [0048]    Once activated, an electric current is made to flow between the first plate  18  and the second plate  22 . The third plate  24  is brought to the voltage level of the first plate  18  through the third electrical connection  17 . By effectively activating the entire floor area, the likelihood of rodent escape is reduced, more surely resulting in fatal electrocution of the rodent. 
         [0049]    The three-killing-plate and IR sensor configuration of the present invention may be incorporated into other representative embodiments of an electronic trap suitable for use with the circuitry of the present invention, such as the diverter trap which is fully disclosed in the &#39;899 patent and previously incorporated by reference. The IR sensor  32  can also be employed with a two-killing-plate configuration with the plates being of equal or unequal sizes. Regardless of the relative plate sizing in such a two-killing-plate configuration, the IR sensor is positioned between the two plates so as to direct the IR beam signal across the width of the trap. 
         [0050]    The operation of the high-voltage, rearming circuitry of the present invention in conjunction with traps of the foregoing types will now be described with reference to  FIG. 7 , which illustrates a flow chart of the electrical circuit according to the present invention;  FIG. 8  illustrates the same circuit in schematic form. The reference in  FIG. 7  to a “rat” as the subject pest is representative only and is intended to include all vermin to which the trap according to the present invention may be applied. 
         [0051]    To commence operation of the trap, power is applied to the high-voltage output circuit  10 , either from a battery or an electrical outlet. The unit is turned on, step  300 , by a user using the switch  26 , thereby placing the trap into an enabled condition. Upon entry into the enabled condition, the LED  28  flashes green once, step  302 , and then turns off. The high-voltage output circuit  10  detects the battery status and, if the battery power is low, step  304 , the LED flashes red one or more times, step  306 , as a visual indicator to the user that the batteries should be replaced. Upon conclusion of the red LED flashing procedure, and also if the battery power is found to be sufficient in step  304 , the unit remains in the enabled condition in a standby mode, step  308 . 
         [0052]    As an alternative indicator in the event of low battery power, the LED may flash red on a continuing and regular basis. If the trap includes only one LED, then green flashing thereof concurrent with the red flashing will change the output color of the LED to indicate to the user that both conditions are being reported. The red and green colors are provided by diodes of appropriate colors within the circuit. 
         [0053]    The circuit  100  is triggered or activated, step  310 , by interruption of the IR beam signal for the threshold time period as described above. Once activated, the circuit  10  delivers a high voltage pulse train to the killing plates  18 ,  22 ,  24 . The high voltage pulses delivered to the killing plates are preferably delivered as a pulse train of at least about 7500V occurring every 4.25 ms over about a 120-second killing cycle, step  312 . Upon completion of the killing cycle, current to the plates is terminated, and the battery level is checked, step  314 . As before, if the battery power is low, step  314 , the LED flashes red one or more times, step  316 , as a visual indicator to the user that the batteries should be replaced. Upon conclusion of the red LED flashing procedure, and also if the battery power is found to be sufficient in step  314 , the unit checks a stored trigger count, step  318 , to determine if the circuit has been activated three times since entering the standby mode at step  308 . 
         [0054]    If the trigger count is equal to three, flashing of the green LED at a regular interval is initiated, step  320 , and the unit does not reenter the enabled condition. Particularly, the LED flashes green once, checks to see whether 24 hours have elapsed, step  322  and, if 24 hours have not elapsed, repeats the flash and check cycle, steps  320  and  322 . According to a preferred embodiment, the LED flashes green once every 5 seconds. When 24 hours have elapsed following the initiation of step  320 , the unit is turned off, step  324 . 
         [0055]    If the trigger count is less than three, the IR transmitter  50  resumes emission of the IR beam signals at a preferred rate of about 50 msec every second. If the IR receiver  52  does not receive two consecutive signals, step  326 , this indicates the continued presence of the rodent whose body is blocking the beam signal. The unit then initiates the regular flashing and checking cycle, steps  320 ,  322 , to visually notify the user that the trap contains an electrocuted animal. The green flashing of the LED continues until the user services the trap or for a 24 period, step  322 , whichever occurs first, after which the unit is turned off. 
         [0056]    If, after IR beam signal emission has resumed following the killing cycle, the IR receiver  52  does receive the IR beam signals, step  326 , i.e., there is no rodent between the transmitter and the receiver, the unit rearms to the enabled condition in standby mode, step  308 , and thereafter awaits another rodent trigger. In this case, the LED does not illuminate, precluding the user from responding to a false-positive condition. 
         [0057]    According to the preferred embodiment as illustrated in  FIG. 7 , in the event that the presence of the rodent is not detected following the killing cycle, the circuit will rearm itself twice in the manner just described, preferably within five seconds of completing the killing cycle. Once the unit has been triggered three times, step  318 , the flashing and rechecking cycle is entered, steps  320 ,  322 , regardless of the status of beam interruption, followed by unit shut-down after 24 hours. As would be apparent to persons of skill in the art, the circuit may be designed to rearm a greater or fewer number of times before turning off, depending upon system and user requirements. 
         [0058]    As stated previously, the present invention may be embodied with other sensing elements such as a photocell sensor, a motion sensor, or a reflective sensor, for detecting the presence of a rat in the trap. Photocell sensors are well known and have been used to limit activation of an associated circuit to day or night hours, while motion sensors are widely used to detect intruders in a given area. Reflective sensors have been used reliably in public plumbing fixtures for several years. The emitter and detector are combined in a single package in the reflective sensor which may be embodied as a printed circuit board mounted behind a protective window. A reflective sensor is advantageous as no external wiring is required inside the trap chamber, eliminating the need for the bracket. 
         [0059]    The foregoing is considered as illustrative only of the principles of the invention. Since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described and, accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.