Abstract:
Releasable sinkers for marine applications are described, each of which utilizes rapidly disintegrating water soluble material as an attachment means or as part of an attachment assembly for securing a weight to fishing line. Depending on the configuration of the rapidly disintegrating water soluble material, after exposing the sinker to water, for example, by casting a line into the water or by returning a caught fish back into the water, the rapidly disintegrating water soluble material will dissolve, thereby releasing the sinker from the fishing line. The weighted portion of the sinker, which provides the majority of sinker weight, may be preferably formed from an organic material that will also eventually dissolve in water, although at a much slower rate than the rapidly disintegrating water soluble material.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application 61/813,404 filed on Apr. 18, 2013, which is fully incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to sinkers for marine applications, particularly to sinkers that automatically release from fishing line by action of water soluble material. 
         [0004]    2. Description of Related Art 
         [0005]    Related art is described in U.S. patent application Ser. No. 14/156,109 of applicant Robert Paul Bono, which application is fully incorporated herein by reference. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention provides advancements in the art of releasable sinker design for marine applications. Three related embodiments are described, each of which utilizes rapidly disintegrating water soluble material as an attachment means or as part of an attachment assembly for securing a weight to fishing line. Depending on the configuration of the rapidly disintegrating water soluble material, after exposing the sinker to water, for example, by casting a line into the water or by returning a fish back into the water, the rapidly disintegrating water soluble material will dissolve, thereby releasing the sinker from the fishing line. The weighted portion of the sinker, which provides the majority of sinker weight, may be preferably formed from an organic material that will also eventually dissolve in water, although at a much slower rate than the rapidly disintegrating water soluble material. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. Component parts shown in the drawings are not necessarily to scale, and may be exaggerated to better illustrate the important features of the invention. Dimensions shown are exemplary only. In the drawings, like reference numerals may designate like parts throughout the different views, wherein: 
           [0008]      FIG. 1  is an isometric view of a puck-type design for a releasable sinker according to a first embodiment of the invention. 
           [0009]      FIG. 2  is a perspective view of the puck-type sinker of  FIG. 1 . 
           [0010]      FIG. 3  is a sketch of a sinker assembly showing a piggy-back design for a releasable sinker according to a second embodiment of the invention. 
           [0011]      FIG. 4  is a series of diagrams showing, in three different states of use, a catch-and-release design for a releasable sinker according to a third embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0012]      FIG. 1  shows a puck-type design for a releasable sinker. This design is generally cylindrical, having a base  101  of a greater dimension that its height  103 . In one embodiment, the base  101  may be about 1 ¾ inches in diameter and the height  103  may be about 1 inch. An opening  105  is cut from the side of the sinker to its center, and runs completely through the height of the sinker, as shown. The opening  105  is preferably wider at the perimeter of the sinker than at the center, to facilitate threading fishing line at the center. The opening  105  may be generally wedge-shaped, as shown. In one embodiment, the opening  105  at the perimeter may be about ¼ inch, and may extend toward the center of the sinker, where it may straighten to form a generally rectangular slit  107  about ¼ inch long and about 1/16 inch wide to accommodate fishing line with plenty of margin. A slot  109  is cut through the side of the sinker to an interior side of the opening  105 , as shown. The slot  109  is sized to accommodate a rapidly disintegrating water soluble strip (not shown). In one embodiment, the slot  109  may be generally rectangular having dimensions of about ⅛ inch wide by ⅝ inch high, It may be located, at the perimeter of the sinker, about ¼ inch from the opening  105 . 
         [0013]      FIG. 2  shows a perspective view of the puck type sinker  100 . In this embodiment, the opening  105  is an asymmetrical wedge, with one straight edge and one angled edge; however, in other embodiments the opening  105  may have a symmetrical shape, such as one that comprises a wedge having identically angled sides. This figure shows slot  109  as two slots  109   a  and  109   b  cut on either side of the opening  105 . Slots  109   a  and  109   b  are preferably dimensionally similar, casting mirror images of one another. 
         [0014]    In one embodiment, the weight of the sinker  100  is about 1.75 ounces given a density of sinker material of about 1.3 with respect to the density of water. The sinker  100  may be formed from metal, clay, stone, cement, mortar, or other material having a greater density than water. In another embodiment, the sinker may be formed from a ceramic material having a density of up to about twice that of water. Sizes of sinker  100  may vary to achieve weight from about 1.75 ounces to about 3.5 ounces for the typical dimensions disclosed herein. 
         [0015]    In operation, fishing line is fed into the opening  105  to the center slit  107 . A rapidly disintegrating water soluble material is then pushed through slot  109  from one side to the other (that is, through both  109   a  and  109   b ), to link the fishing line to the sinker. The wall of the rapidly disintegrating water soluble material acts as a gate that will not allow the sinker to detach from the fishing line until some time after the sinker enters the water. When the sinker has been immersed in the water for a period of time sufficient to cause the rapidly disintegrating water soluble material to dissolve, the fishing line is free to emerge from the opening  105 , or equivalently, the sinker  100  detaches and drifts away from the fishing line. The rapidly disintegrating water soluble material may be, for example, a strip of dissolvable paper that is folded a number of times to achieve optimal or desired dimensions and/or dissolving time. 
         [0016]      FIG. 3  shows an embodiment according to the invention of a releasable sinker assembly known herein as the piggy-back design. In this embodiment, a loop  313  of fishing line is attached to a fixed point  320  on a main fishing line  315 . The loop  313  may have either loose ends or reattachable ends that allow one of its ends to be threaded through the fixed point  320  and then both ends attached to a weighted bag  323  at points  319  and  321 . For example, the fishing line loop  313  may pass through the bag  323  at  319  and  321 , or it may be tied or otherwise attached at these locations. 
         [0017]    The fixed point  320  may be, for example, a swivel with at least one eyelet, or a split shot or rubber-core sinker. The weighted bag  323  may contain a low-cost weight such as salt, rocks, gravel, sand, etc.. This weight may typically be about 1 to 3 ounces, though other weights are certainly possible within the scope of the invention. The bag itself may be formed from material such as cloth, paper, or a biodegradable or disintegrating material. 
         [0018]    A dissolvable paper loop  317  forms a link within the fishing line loop  313 , as shown. The dissolvable paper loop  317  is formed from a rapidly disintegrating water soluble material. When the entire fishing sinker assembly  300  enters the water after casting, the dissolvable paper loop  317  dissolves and opens to release the weighted bag  323  from the main fishing line  315 . 
         [0019]      FIG. 4  shows a series of diagrams, representing three different states of use (A, B, C) of a sinker assembly  400 . Sinker  400  is known herein as the catch-and-release design for a releasable sinker according to an embodiment of the invention. This design enables a caught fish under barometric stress to be harmlessly returned to the body of water from which it was caught. Using this device, the fish may be placed into the water and taken down to an appropriate depth where it can repressurize and recover. 
         [0020]    The sinker  400  includes a bag  431  filled with weight and a clamping mechanism  433  that is attached to the top of the bag  431  by a line  435 . The clamping mechanism includes two jaws  437   a  and  437   b  and a coil spring  439 . A wedge  441  formed from rapidly disintegrating water soluble material is threaded onto the line  435 . 
         [0021]    With the sinker  400  resting in its shelf or non-operating state shown in diagram A, the coil spring  439  in the clamping mechanism  433  maintains the jaws  437   a  and  437   b  in an open position, as shown. In operation, for example, when clamping the sinker  400  to a fish&#39;s mouth or gills, the jaws  437   a  and  437   b  are manually closed against the force of coil spring  439  and maintained closed by positioning the wedge  441  between the jaws, as shown in diagram B. The wedge  441  may simply be pushed up along the line  435  until it locks into position between the jaws to wedge them open. This action effectively attaches the caught fish to the bag  431 . 
         [0022]    In further operation, the fish along with the sinker  400  may be released in to the water, so that the weight drags the fish down to a lower depth. As soon as the assembly enters the water, the wedge  441  begins to dissolve, and eventually weakens to the point where the coil spring  439  forces open the jaws of the clamping mechanism  433 , thereby releasing the fish. This state is shown in diagram C. There, what remains of wedge  441  is compressed between the jaws  437   a  and  437   b  under force of the coil spring  439 . 
         [0023]    By selecting the plastic type, or by controlling the surface area and volume of the wedge  441 , the wedge can be made to dissolve at differing rates or to release the clamp at differing depths. Stated differently, various controls on the materials and configuration of the wedge  441  enable the designer to control the amount of time required for the wedge  441  to dissolve to the point where the coil spring forces open the clamping mechanism. Once open, the fish is free to swim away, and has a better chance of survival because it was able to recover at a proper depth and was thus not barometrically stressed by being released at the surface. 
         [0024]    In another embodiment, the clamping mechanism may be replaced with a simple loop of fishing line, wherein a portion of the loop comprises a length of rapidly disintegrating water soluble material. The line that forms the loop may first be threaded through the fish&#39;s gills and then joined in a loop, or it may be a lasso that is tightened behind the fish&#39;s head. The loop is configured so that when immersed, the dissolvable portion breaks apart and opens the loop to free the fish. 
         [0025]    In any of the foregoing embodiments, the rapidly disintegrating water soluble material may comprise a polyvinyl alcohol plastic, a polyglycolic acid plastic, or a dissolving paper product.