Abstract:
An arrangement for displaying the state of a plurality of animal traps is disclosed. Each trap senses the position of a movable trapping portion such as a trap door or jaw and rf transmits the state of the movable portion. A display unit receives the rf transmissions from the traps and identifies and displays the then current state of each trap. The rf signals may be periodically sent from the traps and/or they may be sent in response to a change in state of the movable portion.

Description:
The present application relates to wireless reporting of events and more particularly to the wireless reporting of the state of animal traps. 
     The surveillance of multiple events at a common display is a routine event today. The surveyed events may be present states of doors and windows in a security system which are usually surveyed using hard wired sensors at fixed locations. The system components at the doors and windows are not moved from location to location so re-wiring is not a required event. 
     Certain items such as animal traps are frequently placed in many locations and then moved about as needs arise elsewhere. Ordinarily, an individual must remember where each trap has been placed and occasionally check the traps visually to see whether they have been sprung so that they can be reset and re-baited. The task of trap checking is made even more critical in certain commercial food establishments where prevailing laws invoke penalties if an animal has been trapped for too long a period of time. A need exists for a detection and display system which allows an operator to easily identify which of a plurality of animal traps needs to be tended to and further allowed the easy movement of traps without re-wiring sensors. 
     SUMMARY 
     This need is met and a technical advance is achieved in accordance with the present invention which includes wireless transmitters in association with each of a plurality of animal traps and a central display unit which receives signals from the traps and displays indicia of the state of the trap. 
     In accordance with an embodiment of the invention, each of a plurality of animal traps includes a radio frequency (rf) transmitter and a sensor to detect the position of a movable part of the trap. In the case of a normal rodent trap, the movable portion may be the metal jaw of the trap and in the case of a humane trap, the movable portion may be a closing door. The rf transmitter may periodically transmit a signal which uniquely identifies the transmitting trap and which includes an indication such as set or sprung to indicate the position of the movable portion. The control unit receives each transmission from the animal trap transmitters and decodes it to determine the identity of the trap and the present condition of its movable portion. The central unit may then display the results, for example by means of a pair of light emitting diodes, one for set and one for sprung, associated with each trap designation. In other embodiments the change of state of the movable portion of a trap may trigger the rf transmission of the trap identity and the then current state of the movable portion. As with periodic transmission the central unit responds to each received rf transmission by decoding the information to identify the trap in which a change has occurred and display the current state of that trap. 
     In still further embodiments the rf transmitters of one or more of the traps may transmit status signals both at a regular interval, e.g., 2 minutes, and whenever a state change occurs. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a representation of an animal trap alert arrangement including a plurality of animal traps and a display unit; 
     FIG. 2 is a perspective view of an animal trap; 
     FIG. 3 is a block diagram of circuitry comprised by the animal traps; 
     FIG. 4 is a block diagram of circuitry comprised by the display unit; 
     FIG. 5 shows a table stored by a processor of the display unit; and 
     FIG. 6 is a flow diagram of an embodiment of a controller of the animal trap. 
    
    
     DESCRIPTION 
     FIG. 1 is a representation of an animal trap display system including a central display unit  101  having a receiving antenna  103  and a display board  149  including a list of animal trap identities  105  in association with a list of trap states  107 . As shown, each trap identity e.g.  109  is associated with a pair of light emitting diodes (LED)  111  of different colors. For example, one LED  113  on the left is green to indicate that the associated trap remains set and a second LED  115  is red to indicate that the associated trap needs attention. 
     Also included in the system of FIG. 1 is a plurality of animal traps  1  through n of which trap  1  is assigned reference numeral  117  and trap n is assigned reference numeral  119 . Each trap  117  through  119  includes a trap sensor  121  (FIG. 2) and a wireless transmitter in addition to the normal trap mechanism  125  as shown in FIG.  2 . The trap mechanism in FIG. 2 is a standard household rodent trap, however, other trap mechanisms might be employed. The trap may be a humane trap of the cage variety with a closing door or a more rugged outdoor variety of the clamp trap such as the type used to capture fur bearing animals such as bear and mink. The only requirement of the trap mechanism is that a detector should be able to sense that the trap has been sprung or that the trap contains one or more captured animals. In the following embodiment, the trap is shown and described as a household rodent trap commonly called a mouse trap. The trap includes a movable portion  122  which is used in the normal manner to trap animals. 
     FIG. 3 represents the electrical circuit associated with the traps  117 - 119 . Such circuitry may be embedded within the trap body as shown in FIG. 2 or separate therefrom provided that the circuitry can sense the state of the trap. In FIG. 3 the sensor  121  is represented as a single pole single throw switch  127  which is connected to a controller  129 . The sensor  121  may be mechanically, magnetically, electrically or optically coupled to the moving portion  122  of the trap. The exact nature of the sensor is not critical to applicant&#39;s invention. Also shown is a transmitter  133  with an associated antenna  135 . The transmitter is of a type well known in the art which AM modulates a carrier frequency to transmit signals. It should be mentioned that the transmitters of all of the traps  117 - 119  transmit at the same carrier frequency in the present embodiment, however, such is not required. Also included in the transmitter system of FIG. 3 are an identity code storage  137  and a battery  131 . The code stored by storage  137  is unique to a particular trap so that the code can be decoded at a receiver to identify which trap is transmitting. In the present embodiment, thirty two traps  117 - 119  are possible so the identity code should comprise at least 5 binary digits (bits). Other numbers of traps can be used in other embodiments and codes of different length are necessary. 
     The controller  129  periodically reads the state of sensor switch  127  and transmits a message including the code of the transmitting trap and the then present state of the trap. Additionally, the controller senses each change of state of the trap and transmits a signal within a few seconds of the change of state to contemporaneously signal the new state to a control unit. 
     A block diagram of the central display unit  101  is shown in FIG. 4. A receiver  141  of the central display unit is tuned to receive the rf transmissions from the traps  117 - 119  and to connect the code and trap state received in those transmissions to a processor  143  which may be a programmed micro processor having a memory  145 . Memory  145  stores the program and data for controlling the processor and may consist of a plurality of memory circuits including ROM for the program and non-volatile RAM for storing certain trap related data. Also stored in memory  145  is a data table having an entry for each trap  117 - 119  which stores the last look state of the trap and the identification code representing the trap. The table of trap data is represented in FIG. 5 as  147 . Display unit  101  also includes a display section  149  comprising the pair of LEDs for each trap and a printed designation for the associated trap. As shown in FIG. 4, thirty two trap designations are arranged in a column and the associated pair of LEDs e.g.  113  and  115  are arranged in a row with the trap designations. In addition, the central unit  101  may be equipped to provide trap state data to remote locations when the animal trap identifying system is not readily available. When so equipped, the system includes remote communication unit  146  which is advised of each trap state change detected by processor  143 . Upon being advised, the remote communication  146  dials a preset telephone number to alert a human operator or initiates an automatic e mail message to the operator. 
     Each trap includes a code storage device  137  to store the unique code of the trap. This storage device  137  may be a permanently written code in the ROM of controller  129  or in the present embodiment in a multi position DIP switch. The user sets the positions of the dip switches of each trap to a different combination of positions. The display unit  101  includes a learn mode switch  153  connected to the processor  143  which, when depressed by the user, causes processor  143  to enter the learn mode. In the learn mode, which may last for 10-20 seconds, the processor receives a code and state transmitted from a trap and checks each trap entry of table  147  to see if the received code is being used by another trap. When the code is not already in use and thus is not stored in table  147  the new code is so stored in the next available position of trap table and both LEDs associated with that first available entry are flashed to alert the user of a successful learning operation. When an already in use code is received during a learn operation, such is identified by the check of codes and no LEDs are flashed. Learning mode operation is described in detail in U.S. Pat. No. 4,750,118 which is hereby incorporated by reference, and is generally well known in the art. 
     The present embodiment includes DIP switches in the traps and learning of identity codes by the display unit, however, other methods for trap identification could be used. For example, the traps and display could be sold as a set and each trap identity fixed in the trap and permanently memorized by the display unit. 
     FIG. 6 is a flow diagram of the operation of the trap transmitters  133  during normal operation. The flow begins with a start operation  161  which is initiated by the placement of batteries  131  into the trap. Start operations generally comprise those initialization operations normally performed by a processor on power up. After the start is completed, the flow proceeds to a block  163  in which the state of switch  127  is read and assigned to a variable new_state. Flow then proceeds to store the new_state in a block  165  and the new_state is compared with a variable old_state which is stored by controller  129 . It should be apparent that an old state represents the state of switch  127  and thus movable trap portion  122  during a last check of trap status. 
     When new_state equals old_state, no current state change has occurred and flow proceeds to block  169  to determine whether two minutes has expired since the last transmission. When two minutes has not passed, flow proceeds to a pause block  171  which is used to delay the excursions through the program loop represented by FIG.  6 . During the pause other processor functions may be performed. After the pause which may only be for 0.5 seconds, for example, flow proceeds back to block  163 . 
     When the decision step  169  determines that 2 minutes has passed since the last transmission, flow proceeds to block  173  where a 2 minute timer is reset and on to block  175  in which the identity code of the device is read from storage  137  and both the identity code and new state are transmitted via transmitter  133  and antenna  135 . After such transmission, the variable old_state is set to new_state in block  177  and flow continues to the pause block  171  and back to the program loop discussed above. Similarly, when the performance of decision block  167  determines that new_state and old_state are not equal flow proceeds to the transmit step  175  where the identity code of the trap and the new_state are transmitted as before. From the above it can be seen that the trap continues to test for a state change and for the expiration of two minutes. When either event occurs, the trap code and then present state of the movable portion are rf transmitted and the process continues. 
     In the display unit, the processor continues to scan for received codes. When a valid code is received, it is successively compared with the codes stored in table  147  to identify which trap sent the code. When the trap is identified, memory  145  table  147  for the just received trap code is updated to represent the new_state of the trap. Processor  143  also performs a continuous loop to read the states of the traps  117 - 119  from memory  145  and energize the appropriate LED e.g.  113  to visually represent the trap state. 
     When operating as above described, a baited trap will continue to send a state indication that the trap is ready for use. When an animal takes the bait and springs the trap, the movable portion  122  of the trap moves to catch the animal. The sensor  121  will detect the movement of the movable member and when controller  129  next reads the sensor a signal will be sent to the display unit to reflect the state change. Alternatively, as long as the trap remains unsprung and the movable portion does not move the transmitter  133  will be used every 2 minutes to notify the display unit that the state has not changed.