Abstract:
A remotely activated door-opening mechanism is provided for a cage trap having an animal enclosure, preferably a cage trap as disclosed in U.S. Publ. No. US2008/0115405. The mechanism is mounted outside the enclosure of the trap and is preferably remotely activated by an IR or RF transmitter to open a door of the trap and release a trapped animal when the operator is at a safe distance away. The mechanism may also be manually set with a time delay and may be associated with either a main entry door to the trap or with a secondary escape door located at an opposite end of the trap.

Description:
This application is entitled to and hereby claims the priority of U.S. Provisional application Ser. No. 61/136,676 filed Sep. 24, 2008. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to cage-type animal traps of the kind generally used outdoors for trapping small to medium sized animals without harming the trapped animal. 
     2. Description of the Prior Art 
     Cage-type traps generally include a cage of metal wire mesh or the like with a door held open by a trigger mechanism until an animal is lured into the trap by suitable pre-inserted bait. After the animal enters the interior of the trap, the animal&#39;s weight pressed against the trigger actuates a trip which releases and closes the door, thereby trapping the animal inside the cage. A locking device serves to prevent the animal from opening the door from the inside. 
     To release the trapped animal, the locking device must be disengaged and the door must be opened. These steps generally require the use of two hands and involve close contact with the animal. 
     One solution to the problem of close contact with the trapped animal is set forth in copending application, U.S. Ser. No. 11/600,085, filed Nov. 16, 2006 (“the &#39;085 application”), and published as U.S. Publ. No. US2008/0115405 on May 22, 2008, which is commonly owned by the assignee of the present application. The disclosure of the &#39;085 application is hereby expressly incorporated by reference in its entirety as if fully set forth herein. 
     In the &#39;085 application, the door at the front of a cage-type trap is held in the open position by an over-center set mechanism mounted on the roof of the trap. A cable assembly extends from the set mechanism to a point of connection on the door and a torsion spring, operatively connected to a locking yoke that engages the door, urges the door toward its closed position when the trap is triggered by an animal. 
     In addition to the cable assembly, the over-center set mechanism further includes a set mechanism platform attached to the roof with a transversely extending set lever bracket mounted thereon. A generally U-shaped set lever is pivotally coupled to both ends of the bracket so as to be movable through slightly less than 180 degrees from one side of the bracket nearest the rear of the trap in the set position to the other side of the bracket nearest the front of the trap in the tripped position. Generally centered on the set lever is a lever grip that can be grasped by a user when setting the trap to facilitate placement of the set lever in the set position. 
     The over-center set mechanism disclosed in the &#39;085 application can be set using only one hand. Accordingly, opening the door of the trap to release a trapped animal requires only one hand, allowing the user to maintain a greater distance from the front of the trap than is possible with traps requiring two hands to place the trap door in the open position. Nonetheless, the user must grasp the lever grip and move it manually, necessitating that the user be immediately adjacent the trapped animal. When releasing a potentially dangerous animal, this may subject the user to an unacceptably close encounter when the animal exits the trap. 
     Similar concerns arise as well with other trap designs which require that the user physically open the trap to release the animal. 
     There is thus a need for a mechanism by which an over-center type cage trap such as that disclosed in the &#39;085 application, or other style traps, may be remotely activated to open an escape door from a distance so that the user can easily release a trapped animal without subjecting the user to close contact with the trapped animal. 
     SUMMARY OF THE INVENTION 
     The present invention is therefore directed to a remotely activated cage door opening device for use with a cage-type animal trap that has a wire mesh animal enclosure made up of a base, a pair of opposed sidewalls emanating from the base, a rear wall secured to the sidewalls and the base, a roof secured to the tops of the sidewalls and the rear wall, and a front end provided with an animal access opening defined by the base, sidewalls, and roof. 
     According to a first embodiment, a single door is movably mounted at the front end and operates in an opened position to reveal the animal access opening and in a closed position to block the animal access opening. The door is held in its open position by an over-center set mechanism as disclosed in the &#39;085 application which has a set handle mounted on the roof and a cable assembly that extends from the set handle to a point of connection on the door. 
     The remotely activated cage door opening device includes an infrared (IR) receiver and associated circuitry, a rotatable spool and cable, and a latch pawl at least partly enclosed within a housing. One end of the spool has a toothed sprocket that ratchets against the latch pawl and the other end of the spool engages a torsion/clock spring in the housing. The cable is wound on the spool with at least one free end thereof coupled to a fastening element that is secured to the set handle of the trap. The door opening device also includes an attachment element to secure the housing to the trap enclosure. 
     When the device is secured to the trap by the attachment element and the trap has been tripped so as to trap an animal inside, the cable is pulled off the spool against the tension of the torsion/clock spring until the fastening element can be clipped onto the set handle. The ratcheting of the sprocket against the pawl allows the extracted cable to remain extended without a retraction force. 
     The IR receiver includes a solenoid which is operative to release the latch pawl from the sprocket when actuated by a remote wireless IR transmitter. Once released, the cable is retracted onto the spool by the stored energy in the wound tension spring, automatically opening the door to which the cable is attached. 
     According to a second embodiment, the entry door is as already described in connection with the door of the first embodiment but, in addition thereto, a secondary escape door is provided at another location in the trap body, preferably at the rear end of the trap opposite the entry door at the front end. The secondary escape door operates independently from the entry door and is movable between closed and opened positions to either cover or uncover an escape opening formed in the side or end wall of the trap. A door release unit secures the secondary escape door in the closed position until activated, either by remote control or other release mechanism. Once activated, the escape door is free to move to the opened position at which time an animal inside the trap can escape through the escape opening while the entry door remains closed. 
     It is thus an object of the present invention to provide a remotely activated door-opening mechanism for a cage trap demonstrating mechanical and electronic simplicity for ease of opening the trap&#39;s door without requiring the user to have physical contact with the trap. 
     It is a further object of the present invention to provide a door-opening mechanism for a cage trap that is remotely controlled by a wireless IR transmitter to allow the user to maintain a safe distance from the trap when releasing a trapped animal. 
     It is another object of the present invention to provide a cage trap door-opening mechanism in accordance with the preceding objects and a first embodiment that can be retrofit onto existing cage traps equipped with an over-center set mechanism. 
     It is yet another object of the present invention to provide a door-opening mechanism for a cage trap in accordance with the preceding objects and the first embodiment that can be easily attached to and then removed from the cage trap as an accessory, allowing the same mechanism to be moved from one trap to another for opening the respective doors thereof. 
     It is still another object of the present invention to provide a door-opening mechanism for a cage trap in accordance with the preceding objects that is relatively simple in electronic design while providing robust mechanical operation to open the trap door. 
     It is a further object of the present invention to provide a cage trap in accordance with a second embodiment having a main entry door through which an animal enters the trap and a secondary escape door that operates independently of the entry door such that, once the animal has been trapped inside the cage, the user can remotely release the animal by triggering the opening of the secondary escape door while the entry door remains closed. 
     It is yet another object of the present invention to provide a cage trap in accordance with the preceding object in which opening of the secondary escape door is controlled by a door release unit that can be activated either using a remote control unit or with a mechanical time release. 
     Additional objects of the invention include, for example, the provision of a door-opening mechanism for a cage trap which is durable, reliable and user friendly, and which can be manufactured from readily available components and in a cost-effective manner. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects, features and advantages of the present invention will be apparent to those skilled in the art upon a reading of this specification including the accompanying drawings. While intending to illustrate the invention, the drawings are not necessarily to scale. 
         FIG. 1  is a perspective view of a preferred embodiment of the present inventive door-opening mechanism as mounted on a cage trap in a tripped position with the door of the trap closed. 
         FIG. 2  is an exploded perspective view of the components of the door-opening mechanism shown in  FIG. 1 . 
         FIG. 3  shows a left side view of the front end of the housing to illustrate the sliding clip for securing the housing of the door-opening mechanism to the trap roof at the rear of the trap enclosure as shown in  FIG. 1 . 
         FIG. 4  shows an alternative embodiment to the clamp of  FIG. 3 , in which the door-opening mechanism includes clips on both ends of the cable, one clip for securing the mechanism to the trap enclosure and the other clip for securing the cable to the door. 
         FIG. 5A  shows a cage trap having a secondary escape door in accordance with a further embodiment of the door release mechanism of the present invention, the secondary escape door being shown in a closed position. 
         FIG. 5B  shows a partial view of the cage trap of  FIG. 5A  with the secondary escape door being shown in an opened position. 
         FIG. 5C  shows a user activating the trap of  FIGS. 5A and 5B  from a safe distance using a remote control unit. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In describing preferred embodiments of the present invention illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. 
     As shown in  FIGS. 1 and 2 , the remotely activated cage trap door-opening mechanism according to a first embodiment of the present invention is generally designated by reference numeral  10  and is mounted at the top rear of a cage trap as disclosed in the aforesaid &#39;085 application. The door opening mechanism  10  includes a mechanical assembly, generally designated by reference numeral  12 , and an activating assembly, generally designated by reference numeral  14 . The activating assembly and portions of the mechanical assembly are contained within a housing  16  which is mounted to the trap  18 . 
     The mechanical assembly  12  includes a rotatable spool  20 , a toothed sprocket  22 , a latch pawl  24 , a torsion/clock spring and a cable  28  with a fastening element  30 . The toothed sprocket  22  is mounted on one end of the spool  20  so as to ratchet against the latch pawl  24  within the housing. The torsion/clock spring  26  is mounted on the opposite end of the spool  20 . The cable is wound on the spool  20  with the extendible end thereof coupled to the fastening element  30 . The fastening element  30  may be embodied as a clip, such as a carbineer style clamp, by which the extendible end of the cable  28  is secured to the set lever  40  of the trap  18 . 
     The mechanical assembly  12  also includes an attachment element  32  to secure the housing  16  to the trap  18 . This attachment element  32  may be embodied as a sliding clip element  34  (see  FIG. 3 ), as a carbineer style clamp  33  (see  FIG. 4 ), or as any other suitable clamp or fastening mechanism as would be understood by persons of ordinary skill in the art. 
     According to one preferred embodiment, the activating assembly  14  includes an IR receiver generally designated by reference numeral  50  and a remote IR transmitter  52 . The receiver  50  includes a circuit board  54 , a power source such as a battery  56 , and a solenoid  58  operative to release the latch pawl  24  from the sprocket  22  when actuated by the remote IR transmitter  52 . Alternatively, the receiver may be configured for RF communication with a remote RF transmitter. 
     To use the door-opening mechanism, the housing  16  is secured to the upper rear edge  44  of the trap enclosure  42  by the attachment element  32 . The housing  16  may be secured to the trap prior to use, i.e., prior to setting the trap, or may be attached to the trap after an animal has been trapped. If the housing  16  is secured to the trap prior to use, according to a preferred method of use, the extendible end of the cable  28  is not attached to the set lever  40  of the trap  18  until after the trap has been tripped and the animal is to be released. 
     The trap  18  is set by moving the set lever  40  toward the rear of the trap  18  in the manner described in the &#39;085 application. When the trap  18  is tripped by an animal, the set lever  40  moves toward the front of the trap under the urging of the weight of the door  46  as conveyed through the trap cable assembly  48 . Once the door is closed, the animal is trapped inside. 
     To release the animal, the housing is secured to the upper rear edge  44  of the trap enclosure  42 , if not already secured thereto. The free end of the cable  28  is pulled out of the housing to extract the cable  28  from the spool  20  against the tension of the torsion/clock spring  26  until the fastening element  30  is positioned to be clipped onto the set lever  40 . The ratcheting of the sprocket  22  against the pawl  24  allows the extracted cable  28  to remain extended without a retraction force. 
     With the end of the cable  28  attached to the set lever, the user may withdraw a desired distance away from the trap. Once the user is at a safe distance, the user or another individual having the remotely located IR transmitter  52 , actuates the IR receiver  50 . Actuation of the IR receiver  50  activates the solenoid  58  which, in turn, releases the latch pawl  24  from the sprocket  22 . Once the pawl  24  is released, the spool  20  is free to spin and thereby retract the cable  28  onto the spool  20  by the stored energy in the wound tension spring  26 . The retraction of the cable  28  pulls the set lever  40  toward the rear of the trap to automatically open the door  46 . 
     To soften any abruptness in the rapid cable retraction, a rotary dampener  60  may be added to the mechanical assembly in a manner known to those skilled in the art. 
     As described herein, the cage trap door-opening mechanism is an independent accessory that can be easily attached to and then removed from any existing cage trap equipped with an over-center set mechanism to remotely open the door thereof. 
     Other mechanical assemblies suitable for the operation of the present invention could also be used as would be understood by persons of ordinary skill in the art. For example, the cable spool and cable could be operated by an electric motor or a hand-wound crank. Retraction of the cable could also be effected by a pneumatic cylinder. 
     Similarly, as alternatives to the IR transmitter and receiver, or to an RF transmitter and receiver, other remote means of conveying a signal and of receiving the signal by a receiver or comparable device on the activating assembly are also intended to be included within the present invention. The door-opening mechanism could also be mechanical or electrically timed. Activation of the door-opening mechanism could also be accomplished through the use of a wired remote or by a remote mechanical mechanism. 
     Any of the above-described assemblies for operation and activation of a remote door-opening mechanism may also be used in conjunction with a trap having a separate escape door such as that illustrated in  FIGS. 5A and 5B  and generally designated by reference numeral  62 , in accordance with a second embodiment of the present invention. The separate escape door  62  is preferably positioned at the opposite end of the trap relative to the entry door  46 . Since the entry door  46  of the trap shown in  FIG. 1  is described herein as being at the trap front end, then the separate escape door  62  is preferably at the rear end of the trap. Alternatively, the separate escape door could be positioned on the side of the trap, preferably near the rear end. Wherever its location, the separate escape door  62  may be more simply designed than the entry door, requiring only a movable panel that can be positioned and held in a closed position, as shown in  FIG. 5A , to cover an escape opening  64 , and then moved to an opened position to uncover the escape opening, as shown in  FIG. 5B . 
     In the embodiment shown in  FIGS. 5A and 5B , the escape door  62  is pivotally mounted to the end wall  66  of the trap by a hinge  68  positioned at the bottom of the escape opening  64 . When the trap is in a set condition for trapping an animal as shown in  FIG. 5A , the escape door  62  is held vertically in a closed or secured position by a door release unit generally designated by reference numeral  70 . 
     The door release unit  70 , in the embodiment shown, includes a control assembly  72  mounted on the trap body, preferably on the roof  76 , and a catch  74  mounted on the escape door  62  so as to be adjacent the control assembly  72  when the escape door is in the closed position. Alternatively, the control assembly  72  may be mounted adjacent one side of the escape door with the catch then being placed on the escape door in generally horizontal alignment with the control assembly. With this alternative placement of the release unit, the escape door may be secured to the trap by a vertical hinge (not shown) positioned on the opposite side of the door so that the escape door is configured to swing between opened and closed positions while remaining in a vertical orientation. 
     The control assembly  72  includes a latching mechanism (not shown) for securing the catch  74  to keep the escape door in the closed or secured position until the control assembly  72  is activated. The latching mechanism can use mechanical, electrical, magnetic, or other means to keep the catch  74  engaged with the control assembly. When this engagement is released by the control assembly, the door and catch are allowed to pivot downwardly away from the control assembly to uncover the escape opening  64 . 
     According to one preferred embodiment, the door release unit  70  is battery powered and remotely activated by a user  78  using a remote control unit  80  as shown in  FIG. 5C . Alternatively, the door release unit  70  can be designed to operate using a mechanical time release, such as that described in U.S. Pat. No. 3,638,346, by which a manually set timing device triggers the opening of the escape door after the manually set time period has elapsed. In conjunction with such a mechanical time release, the escape door may be spring loaded so as to be ready to swing open when the door release unit is triggered by the timer. 
     However configured, the present invention provides a door-opening mechanism that is easy to use and which, through the remote control activation capability, allows the user to maintain a safe distance from the trap when releasing a trapped animal. 
     It is to be understood that the present invention is not limited to the illustrated embodiments described herein. Modifications and variations of the above described embodiments of the present invention are possible as appreciated by those skilled in the art in light of the above teachings.