Abstract:
A tool for releasing excess air from the swim bladder of a fish. The present invention includes a puncturer situated in a housing and a push rod which extends out of the housing for pushing the puncturer out of the housing and into the swim bladder of the fish. When the tool is employed, the excess air passes through the puncturer into the housing and then out vents located in the side wall of the housing. The puncturer is spring biased to remain in the covered position until the user applies an external force to the push rod to expose the puncturer.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to the field of fishing tools. More specifically, the present invention comprises a tool for equilibrating the internal pressure of a fish brought up from “depth.” 
     2. Description of the Related Art 
     Most fish use swim bladders to control their buoyancy. A fish normally expels air from its swim bladder as it returns to the surface from depth such that the volume of air in the fish&#39;s swim bladder remains relatively constant. When fishing at depths greater than 30 feet, it is not uncommon to bring a fish to the surface at such a fast rate that the fish&#39;s swim bladder overexpands (due to the decreasing pressure of water on the fish) and pours out of the fish&#39;s body cavity. While this does not pose a significant problem for fish that are kept by the fisherman, many fish pulled from depth must be released back into the water. This most often occurs because the fish is too small to legally keep without violating a size limit law or because keeping the fish would cause the fisherman to exceed a bag limit law. These released fish have a low probability of survival because of their inability to return to depth rapidly. 
     Only a few tools are currently marketed or otherwise available for equilibrating a fish&#39;s swim bladder before it is released. These devices typically include a puncturer which is used to perforate the swim bladder of the fish allowing the excess air to escape. Several such devices illustrated and described in U.S. Pat. No. 6,065,238 to Carter et al. Such devices suffer from similar shortcomings. First, some devices employ a fixed, exposed puncturer. These devices can be dangerous to use on a boat where the motion of the boat and slippery conditions can cause the fisherman to inadvertently puncture himself or another person on the boat with the tool. In order to make these devices safer, some employ puncturers which are excessively dull. Dull puncturers are difficult to use, however, because more force is required to push the puncturer through the body of the fish. 
     In order to alleviate the problems associated with such devices that employ fixed, exposed puncturers, Carter et al. proposed a tool which uses a moveable puncturer which moves between a covered state and an uncovered state. This design is illustrated in  FIGS. 5 and 6  of the Carter et al. patent. This design is problematic, however, because the user&#39;s thumb must cover the ventilating orifice to hold the puncturer in the uncovered state. 
     As such, it would be beneficial to provide an equilibrating tool which is easy and safe to use. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is a tool for releasing excess air from the swim bladder of a fish. The present invention includes a puncturer situated in a housing and a push rod which extends out of the housing for pushing the puncturer out of the housing and into the swim bladder of the fish. When the tool is employed, the excess air passes through the puncturer into the housing and then out vents located in the side wall of the housing. The puncturer is spring biased to remain in the covered position until the user applies an external force to the push rod to expose the puncturer. A removable cap is provided for covering the push rod when the tool is not being used. 
     To use the tool, the user simply removes the cap, places the bottom surface of the tool on the fish&#39;s abdomen and then presses the push rod. The user continues holding the push rod until all of the excess air is vented through the tool. The user then releases the push rod causing the puncturer to retract into the housing. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a perspective view, illustrating the present invention. 
         FIG. 2  is a perspective view, illustrating the present invention. 
         FIG. 3  is a perspective view, illustrating the present invention. 
         FIG. 4  is a perspective view, illustrating the present invention. 
         FIG. 5  is a perspective view, illustrating the present invention. 
         FIG. 6  is a perspective view, illustrating components of the present invention. 
         FIG. 7  is a section view, illustrating the present invention. 
         FIG. 8  is a section view, illustrating the present invention. 
         FIG. 9  is a perspective view, illustrating components of the present invention. 
         FIG. 10  is perspective view, illustrating how the housing may be separated. 
     
    
    
     REFERENCE NUMERALS IN THE DRAWINGS 
     
         
           10  tool 
           12  housing 
           14  cap 
           16  clip 
           18  surface 
           20  vents 
           22  push rod 
           24  needle 
           26  orifice 
           28  orifice 
           30  syringe 
           32  connector 
           34  bottom portion 
           36  top portion 
           38  mating block 
           40  inner passageway 
           42  flange 
           44  flange 
           46  spring 
           48  air passages 
           50  receiver 
           52  manifold 
           54  gaps 
       
    
     DESCRIPTION OF THE INVENTION 
     The present invention, a tool which may be used to release excess air from the swim bladder of a fish, is illustrated in  FIG. 1 . Tool  10  includes housing  12  and cap  14  which is removable attached to one end of housing  12 . Cap  14  includes clip  16  which may be used to attach tool  10  to a pocket or other object. Housing  12  includes surface  18  and sidewall vents  20  at the end of housing  12  opposite of cap  14 . 
     Turning to  FIG. 2 , cap  14  has been removed to reveal push rod  22 . Push rod  22  extends into housing  12  where it mechanically engages the puncturer. As shown in  FIG. 3 , when push rod  22  is pressed into housing  12 , needle  24  extends past surface  18 . Thus, in order to use the invention, the user would normally grasp housing  12  with his or her palm and fingers and place the thumb on top of push rod  22 . To improve gripping in wet conditions, a molded rubber gripping surface is provided on the side wall of housing  12 . 
       FIGS. 4 and 5  show tool  10  from the bottom with the puncturer in the covered state and exposed state, respectively. As shown in  FIG. 4 , needle  24  is contained within housing  12  behind surface  18 . As shown in  FIG. 5 , when push rod  22  is pressed into housing  12 , needle  24  extends through orifice  28  in surface  18 . Needle  24  has orifice  26  at one end which is fluidly connected with an internal conduit. In the preferred embodiment, needle  24  is a 16 gauge hypodermic needle. This is the preferred thickness to facilitate the quick evacuation of excess air from the swim bladder without causing unnecessary injury to the fish. 
       FIG. 6  shows a detailed view of some of the “moving” internal components of tool  10 . Needle  24  is attached to syringe  30  by connector  32 . The puncturing end of needle  24  is cut at an angle to facilitate penetration of the body of the fish. 
     Turning to  FIG. 7 , the user will note that the conduit passing through needle  24  is fluidly connected with the hollow interior of connector  32  and the hollow interior of syringe  30 . Needle  24  is normally contained in inner passageway  40  of housing  12 . This prevents the user from inadvertently sticking himself or herself with needle  24  when handling tool  10 . 
     Housing  12  includes top portion  36  and bottom portion  34  which attach together to hold the internal components of tool  10  in place. Top portion  36  and bottom portion  34  join around mating block  38 . Mating block  38  maintains the alignment of syringe  30  and needle  24  as needle  24  travels from the covered position (shown in  FIG. 7 ) to the exposed position (shown in  FIG. 8 ). The reader will note that needle  24  travels along its central axis as it moves from the covered position to the exposed position. 
     Spring  46  is used to bias needle  24  in the covered state until the user exerts an external force on push rod  22 . One end of spring  46  nests in receiver  50  of mating block  38 . The other end of spring  46  mates with flange  44  of syringe  30 . Push rod  22  is insertedly situated in the hollow interior of syringe  30 . Flange  42  of push rod  22  mates with flange  44  of syringe  30  so that the external force supplied to push rod  22  is transmitted to syringe  30 . 
     As shown in  FIG. 8 , spring  46  compresses between mating block  38  and flange  44  when push rod  22  is pushed into housing  12 . Also, when push rod  22  is inserted into housing  12 , syringe  30  extends through mating block  38  into inner passageway  40  and needle  24  extends through the orifice in the bottom surface of housing  12  as previously described. 
       FIG. 9  shows tool  10  with mating block  38  and top portion  36  of housing  12  removed. The reader will now observe gaps  54  which are provided in flange  42  of push rod  22 . Gaps  54  allow air to pass from the hollow interior of syringe  30  into top portion  36  of housing  12 . The reader will also observe that bottom portion  34  includes manifold  52  which is fluidly connected with vents  20 . 
     With the various components of the invention now described, the reader can now appreciate how tool  10  is used to relieve excess air from the swim bladder of a fish. To use tool  10 , cap  14  is first removed to uncover push rod  22 . Surface  18  is then placed against the abdomen of the fish and push rod  22  is pushed into housing  12 . Referring to  FIG. 8 , pressurized air from the swim bladder of the fish is forced into the internal conduit of needle  24  and on into syringe  30  where it exits through gaps  54  in flange  42 . The air then passes from top portion  36  of housing  12  into manifold  52  in bottom portion  34  of housing  12  through air passages  48  in mating block  38 . Turning to  FIG. 9 , the air then exits manifold  52  through vents  20 . As such the air exits housing  12  in a lateral direction relative to the center axis and direction of travel of needle  24  and syringe  30 . Push rod  22  is held in its depressed state until all of the excess air is evacuated from the fish. The user may squeeze the fish lightly to facilitate the flow of air out of the swim bladder. The user then releases push rod  22  so that needle  24  retracts into housing  12 . 
     Referring back to  FIG. 8 , the reader will note that surface  18  generally forms a plane that lies at an approximately 45 degree angle with respect to needle  24 . This feature allows needle  24  to penetrate the swim bladder at the preferred 45 degree angle when surface  18  is placed flush against the “skin” of the fish behind the fish&#39;s pectoral fin and push rod  22  is depressed. This angle is believed to be optimal for relieving pressure without causing vital injury to the fish. 
     Also, as shown in  FIG. 10 , the housing of tool  10  may be disassembled by disjoining bottom portion  34  from top portion  36  and mating block  38 . Such disassembly may be used to facilitate cleaning of tool  10  or replacement of needle  24 . Needle  24  and connector  32  are preferably an integrated unit which may be removed from the base of the syringe when needle  24  dulls or becomes damaged. A new needle and connector unit may then be attached to the base of the syringe. 
     Although the various components of tool  10  may be made of many different materials, it is preferred that a sufficient amount of low density material be used to enable tool  10  to float in the water. This would enable the user to easily retrieve tool  10  if it were inadvertently dropped from a boat. 
     The preceding description contains significant detail regarding the novel aspects of the present invention. It should not be construed, however, as limiting the scope of the invention but rather as providing illustrations of the preferred embodiments of the invention. Thus, the scope of the invention should be fixed by the following claims, rather than by the examples given.