Abstract:
An ice fishing tip-up system includes a rod, a fishing line, a bobber stop coupled to the fishing line, and a tip-up device. The tip-up device includes a base, an arm extending from the base, a lever supporting a line-engaging end having a set slot through which the line will pass, but not the bobber stop, and a flag attached through a resilient wire to the base. Distal to the line-engaging end is a trip end. The resilient wire applies a spring force to the trip end of the lever, the effect of which is variable depending upon the distance between the wire point of contact of to lever and the lever pivot point. A base serves to support the lever, insulate the ice hole to prevent the hole from freezing shut, and provides a selectively opened slot for separating the base from fishing line.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. provisional patent application Ser. No. 60/570,055 filed May 11, 2004 of the same title and naming the same inventor, the contents which are incorporated herein by reference in entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention pertains generally to fishing, and more particularly to signaling devices indicative of a strike on a fishing line and to an ice fishing hole cover incorporating the signaling device. 
     2. Description of the Related Art 
     Ice fishing is widely practiced throughout the world, by persons of all ages and backgrounds. The ice fisherman will first make a hole in ice formed on a body of water, and then will pass a line terminated by a baited hook through the hole. In its simplest form, ice fishing equipment might include a simple pole having a length of line, a hook attached to the line, and a weighted sinker attached above the baited hook. However, to conveniently monitor the status of baited hooks employed during ice fishing, sometimes from a distance and at other times merely for the convenience of the fisherman to free up hands for other tasks or activities, a tip-up is frequently utilized. A tip-up will commonly employ a visual indicator to indicate a strike, and a guide for centering the fishing line in the ice hole. In the prior art, the tip-up may be combined directly with a fishing line into a unitary device, or may alternately be provided as a separate device used in combination with a separately provided ice fishing pole. The fishing line with baited hook is coupled to tip-up, and an indicator on the tip-up responds to disturbances at the baited end of the line. 
     Exemplary of the prior art tip-ups is U.S. Pat. No. 4,993,182 to Monsen, the teachings which are incorporated herein by reference. Monsen illustrates a cover, a standard extending vertically from the cover, and a signaling flag. The flag is triggered by motion of a reel upon which fishing line is wound. Unfortunately, in the Monsen design, a fisherman is limited to the reel disclosed therein, and has no choice of rod or reel. Furthermore, the base or cover fully encompasses the fishing line as the line passes into the hole. While this at first blush helps to prevent freezing within the hole, the cover also presents an undesirable obstacle during the landing of a fish. In another patent of interest, U.S. Pat. No. 5,911,569 to Isakson, the teachings which are also incorporated herein by reference, some of the limitations of Monsen are addressed. Nevertheless, Isaakson lacks desirable control over sensitivity, and requires a substantial cover and apparatus which are undesirable from both a cost and transporting perspective. 
     Additional patents of interest include U.S. Pat. Nos. 5,450,687 to Fox; 5,074,072 to Serocki et al.; 4,980,986 to Harper; 4,823,494 to Waterman; 4,685,240 to Fralick; 4,373,287 to Grahl; 4,270,297 to Yates; 3,578,748 to Hurd; 3,466,781 to Nelson et al.; 3,041,770 to Witbro; 2,714,270 to Premo; 2,008,555 to Kovane; 962,420 to Dibbles; 202,818 to Hesse; 77,893 to Koehler; and 76,489 to McCaughan, the teachings of each which are incorporated herein by reference. Unfortunately, the known tip-ups can be cumbersome, may lack sensitivity or be overly sensitive, are prone to freezing in the fishing hole, and are limited in application to use with simple or particular ice fishing poles. 
     SUMMARY OF THE INVENTION 
     Exemplary embodiments of the present invention solve inadequacies of the prior art by providing an ice fishing tip-up system including a rod, a reel coupled to the rod, and a tip-up device. The reel maintains a length of line and the tip-up device is coupled to the line. The tip-up device includes a base, an arm extending from the base, a bobber stop coupled to the line, and a flag attached to the base. The base is adapted for placement over a hole cut into ice formed on a body of water. The arm extends from the base and couples to a lever at a pivot point, the lever defining a notch end opposite a trip end. The bobber stop is coupled to the line and configured for removable attachment with the notch end of the lever. The flag defines a flag tip movable between a set position and an up position, the set position characterized by the flag tip being coupled to the trip end of the lever. Upon disturbance of the line, the flag tip in the set position releases from the trip end to indicate a strike, and the lever moves about the pivot end to permit line to be stripped off of the reel. 
     In a first manifestation, the invention is an ice fishing tip-up system. The system includes a rod; a length of line; and a stop engaged with the line. A base is adapted for placement over a hole cut into ice formed on a body of water. An arm extends from the base, and supports a lever pivotal about a pivot point between a first ready position and second strike indicative position. The lever has a trip end and a line-engaging end configured for removable attachment with the stop, the line-engaging end being distal to the trip end. A resilient member in a first position extends from the base generally linearly away therefrom and in a second position arcs between base and lever, contacting the lever at a first contact point when in first ready position and resiliently biased to apply a force to the lever encouraging the lever to remain in the first ready position. A magnitude of the biasing force is adjustable by varying a distance between pivot point and first contact point. An indicator is responsive to lever position to indicate the first ready position and the second strike indicative position. 
     In a second manifestation, the invention is an ice fishing tip-up device. The tip-up device has a base adapted for placement over a hole cut into ice formed on a body of water. A lever is pivotal about a pivot point between a first ready position and second strike indicative position and has a trip end and a line-engaging end configured for removable coupling to a fishing line, the line-engaging end distal to the trip end. A resilient member contacts the lever at a first contact point when the lever is in the first ready position. An adjustable force is applied to the lever encouraging the lever to remain in first ready position. An indicator is responsive to the lever position to indicate first ready position and second strike indicative position. 
     In a third manifestation, the invention is an ice fishing hole cover suitable for covering and insulating a hole in an ice layer over a body of water, while permitting an ice fishing line to pass through the cover. The cover has an exposed primarily closed surface with an opening extending entirely through the surface from a first point primarily bounded by the surface to an edge thereof, through which the ice fishing line may operatively pass. A closure is provided that, in a first position, permits the fishing line to pass through the opening from the first point to beyond the edge, and thereby beyond the cover. The closure is additionally operative to close the opening adjacent the edge of the surface, thereby restricting an ice fishing line to an opening through and fully circumscribed by the cover. 
     OBJECTS OF THE INVENTION 
     A first object of the invention is to provide an ice fishing tip-up indicative of whether or not there has been a strike on the line. A second object of the invention is to provide adjustment within the tip-up to accommodate all sizes and types of bait and fish. Another object of the present invention is to enable a fisherman to use preferred ice fishing equipment, including any of the myriad of fishing rods, reels, lines, sinkers, baits and the like, and to be able to fully reel in the line when required. A further object of the invention is to enable longer use of the tip-up in cold weather, by providing a thermally insulating cover. Yet another object of the present invention is to enable the cover, and preferably the tip-up, to be removed if desired during the landing of a fish. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other objects, advantages, and novel features of the present invention can be understood and appreciated by reference to the following detailed description of the invention, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  illustrates a preferred embodiment ice fishing tip-up system designed in accord with the teachings of the present invention and further incorporating a preferred embodiment tip-up device according to the preferred embodiment, from a projected plan view in a “ready” position. 
         FIG. 2  illustrates the preferred embodiment ice fishing tip-up system of  FIG. 1  indicating a strike. 
         FIG. 3  illustrates a preferred notch end of a lever utilized in the preferred embodiment tip-up device of  FIG. 1  from top plan view. 
         FIG. 4  illustrates a preferred base and hole cover utilized in the preferred embodiment tip-up device of  FIG. 1  from top plan view in an open position. 
         FIG. 5  illustrates the preferred base and hole cover of  FIG. 4  from top plan view in a closed position. 
         FIG. 6  illustrates a preferred second layer used in the preferred base and hole cover of  FIG. 4  from top plan view. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A preferred embodiment ice fishing tip-up system  10  designed in accord with the teachings of the present invention is illustrated in  FIG. 1 . Tip-up system  10  includes a rod  12 , a length of line  16 , and a tip-up device  20  coupled to line  16 . Tip-up device  20  includes a base  22  adapted for placement over a hole  24  cut into ice  23 , the ice as is known to form on a body of water during colder weather. In addition, tip-up device  20  includes an arm  26  extending from the base  22  and coupled to a lever  28 . A slip bobber stop  30  or other suitable device as is known in the fishing art is coupled to line  16 , and passes through and removably engages with lever  28 . For the purposes of the present disclosure, a slip bobber stop will be understood to be any device which forms a fixed point on line  16 . In the most preferred embodiment, this is achieved using a specially wound string that loops about and frictionally engages with line  16 . However, it will be understood and recognized that many other similar suitable devices, including but not limited to simple knots in the line, sinkers, small bobbers or other such devices will perform the required function. Nevertheless, a slip bobber stop formed from thread or the like is most preferred, since such can be wound upon a reel without any interference therewith, thereby improving the retrieval of fish. Furthermore, whatever stop is utilized, it will most preferably pass unobstructed through base  22 . A flag  32  is attached to base  22  and is movable between a set position as illustrated in  FIG. 1 , indicative of a “ready” or “active fishing” state and characterized by flag  32  being coupled to lever  28 , and an up position as illustrated in  FIG. 2 , indicative of a “strike” or fish pulling on line  16 . 
     Arm  26  extends from base top surface  22  and couples to lever  28  at a pivot point  44 , thereby spacing lever  28  above base top surface  22  and permitting lever  28  to pivot about pivot point  44  without interference from or with base  20 . Lever  28  has a line-engaging end  50 , and at the opposite end has a trip end  54 . Slip bobber stop  30  couples to line  16  and, when tip-up system  10  is in the “ready” position illustrated in  FIG. 1 , is removably attached to line-engaging end  50 . 
     In this “ready” position illustrated in  FIG. 1 , tip-up device  20  positions the baited end  14  of line  16  at a selected depth by utilizing slip bobber stop  30  to selectively position line  16  within set slot  52 . Slip bobber stop  30  forms a connection to line  16  at a particular point on line  16 , which for the purposes of the present invention will be construed to be a fixed point during operation of tip-up device  20 , but may also be adjustable selectively by the fisherman. Although slip bobber stop  30  or suitable equivalent may slide upon line  16 , such sliding will be understood to occur insignificantly during operation of tip-up system  10  described herein below. As a result, the available line  16  and therefore maximum depth of the line baited end  14  is controlled by the positioning of slip bobber stop  30 . Slip bobber stop  30  secures line  16  to the line-engaging end  50  of the lever  28  by cradling the slip bobber stop  30  within the set slot  52  at the line-engaging end  50  of the lever  28 . In this manner, the tip-up device  20  is in the “ready” position such that the weight of the line  16 , any sinkers, bait, and any additional force delivered by the bait in its movement, is supported by line-engaging end  50  of tip-up device  20 . 
     Flag  32  is retained adjacent flag end  59  of a resilient wire  58 , and wire  58  is attached to base  20  at an opposite end  60 . In the “ready” position illustrated in  FIG. 1 , wire  58  is coupled through flag end  59  to trip end  54  of lever  28 . In a preferred embodiment, wire  58  is frictionally coupled to trip end  54 . In this embodiment, wire  58  may preferably take on a rectangular cross-section, with a width of the cross-section approximating the width of trip end  54 , facilitating placement of flag end  59  on trip end  54 . However, frictional coupling is not solely contemplated herein. Trip end  54  may alternatively include a magnet disposed within lever  28 . In such case, the magnet could also be selectively positioned to adjust magnetic force coupling wire  58  to trip end  54 . In an even further alternative embodiment, other devices or couplings are contemplated herein which are known in the more generic hardware technologies which would perform equivalent function. 
     In the ready state illustrated in  FIG. 1 , the balance of lever  28  is such to hold bobber stop  30  in engagement with line-engaging end  50 . When line  16  is disturbed by a pull on fishing line  16  baited end  14 , thus initiating movement of lever  28  about pivot point  44 , resilient wire  58  releases from this “ready” position illustrated in  FIG. 1  and travels to the up position shown in  FIG. 2  to indicate a possible strike of a fish on line  16 . The amount of pulling force on baited end  14  required to initiate this change of state is dependent upon the balance within lever  28 , the amount of force applied by resilient wire  58 , and the distance between flag end  59  and pivot point  44 . In other words, placement of flag end  59  at greater distances from pivot point  44  will increase the forces required to activate a change of position from “ready” to “strike”. The amount of force will not only be dictated by the distance from pivot point  44  to flag end  59 , but will also be dictated by the spring constant of resilient wire  58 . A change in dimension, composition, or geometry of wire  58  may then be used to adjust the amount of force applied. As may be apparent from the foregoing, a variety of shapes, materials and geometries are contemplated herein, and any suitable member may be used which achieves the intended repositioning of indicator flag  32  and the much desired control of activation force. 
     The control over activation force permits a fisherman to use different types of bait, and to fish for different sizes or types of fish, using the same tip-up system  10  or at least the same tip-up device  20 . For example, when ice fishing for very small pan fish, baited end  14  may comprise either a simple hook or fly, or a hooked worm or the like. In such instance, it may be desired to adjust lever  28  for extreme sensitivity, since a small fish will likely not apply much force, and since the bait itself will apply no force at all. However, when larger fish are being pursued, and perhaps more importantly, when live minnows or the like are used as the bait, the activation force will need to be greater than in the case of pan fishing described above. In this case, minnows may swim about, applying small forces to line  16 . These forces would not be desired to cause activation. Consequently, applying the teachings of the present invention to the preferred embodiment, flag end  59  will be spaced farther from pivot  44  for minnow bait than for pan fishing with worms. 
     Where desired, additional means may be provided for adjusting the activation force. Solely for the purposes of illustration, and not limited thereto, if a magnet is provided within trip end  54 , the magnet may be used to assist with the retention of flag end  59 , presuming wire  58  is, in fact, a ferrous or similar material. However, additional trip force may be provided by providing ferrous or like material within arm  26  as well. The force required to initiate motion within lever  28  will then include the forces produced by wire  58  and additionally the forces necessary to overcome the magnetic attraction between trip end  54  and arm  26 . In one conceived alternative embodiment, wire  58  is simply frictionally coupled to trip end  54 . A steel rivet, washer, post or the like is provided near the termination of trip end  54 , adjacent to arm  26 . A magnet is provided in a special slider, such as a dovetail groove or the like, within arm  26 , and so may be repositioned from immediately adjacent to the steel rivet, or moved farther therefrom. In this alternative embodiment, the magnetic coupling forces, which decrease with a square of the distance, may also be used to control the activation force. In view of the foregoing description of the preferred and alternative embodiments for controlling activation force, it should be apparent that other means or methods of selectively or controllably biasing lever  28  may also be applied, beyond the preferred resilient forces of wire  58  and the alternative magnetic forces, and such other means or methods will be apparent to those skilled in the art upon a review of the present specification. 
     An additional preferred technique for biasing and producing activation force, which further introduces desirable hysteresis in the pivot, is provided through the use of weight  70 . In the “ready” position of  FIG. 1 , weight  70  rests against stop  72 . However, as illustrated in  FIG. 2 , weight  70  slides down lever  28  toward line-engaging end  50  as lever  28  pivots, thereby shifting the balance of lever  28  towards line-engaging end  50 . This motion assists with the full activation of lever  28 , ensuring that lever  28  completely and fully pivots and thereby releases bobber stop  30 . As can be understood from the foregoing description, by adjusting the aforementioned forces from wire  58  and other coupling, and the balance within lever  28 , tip-up device  20  may be adjusted from being highly sensitive to small forces applied to the line  16  to being far more insensitive thereto. 
       FIG. 3  illustrates the end of lever  28  adjacent and including line-engaging end  50 . Set slot  52  is adapted to allow line  16  to pass therein, but is sized to be smaller than slip bobber stop  30 . Consequently, when in the “ready” position illustrated in  FIG. 1 , slip bobber stop  30  will engage line-engaging end  50 , while line  16  passes through set slot  52 . In the view shown in  FIG. 3 , set slot  52  is unoccupied, indicating that flag  32  is in the “strike” position as illustrated in  FIG. 2 . 
       FIGS. 4 and 5  illustrate base  22  in greater detail, from top view and with arm  26 , lever  28  and other indicator and pivot related components removed for simplicity of illustration. Base  22  defines a skirt  40  adapted to fit over and insulate hole  24  cut into ice  23 . In one embodiment, the skirt  40  is a rubber skirt configured to block wind and insulate the exposed water in the ice fishing hole  24 . Skirt  40  may simply extend as a single simple layer down from base  22 , or may alternatively take on any suitable configuration, including the myriad of boot and gasket geometries known from those arts. 
     In the most preferred embodiment illustrated herein, base  22  is fabricated from several circular, relatively planar layers. The top layer  27  of base  22  includes small ears or tabs  25  extending therefrom. A slot  80  is formed entirely through top layer  27 , and extends from a more central location  81  which is generally surrounded by the material of top layer  27 , out to an edge  82  of top layer  27 . A second layer  29  adjacent to top layer  27  includes small ears or tabs  21  protruding therefrom. Rotation of layer  29  relative to layer  27 , which may for exemplary purposes be manually initiated by applying appropriate forces to tabs  21  and  25 , will cause layer  29  to primarily close slot  80 . However, as illustrated in  FIG. 6 , layer  29  has both a radially extending slot  83  and an extension  84  that extends at a fixed radius from the center of layer  29 . The effect of this is illustrated in  FIG. 5 , wherein the opening of slot  80  is inhibited from extending entirely out to edge  82 , and is instead limited to a smaller circle fully surrounded by the layers  27 ,  29 . This reduces air exposure, while still permitting a fisherman to rotate layer  29  to the open position of  FIG. 4  and remove tip-up device  20  completely from the hole, even while a fish is pulling on baited end  14 . In the preferred embodiment, the material(s) used for layers  27 ,  29  will be thermally insulating, to better impede the formation of ice on the open water in hole  24 . 
     While the foregoing details what is felt to be the preferred embodiment of the invention, no material limitations to the scope of the claimed invention are intended. Further, features and design alternatives that would be obvious to one of ordinary skill in the art are considered to be incorporated herein. For exemplary purposes, and not limited solely thereto, it is known in the art to use various types of indicators. While in the preferred embodiment flag  32  serves as a visual indicator, an electrical circuit could alternatively be provided which would activate a local or remote light source, sound or other suitable indicator. In another conceived embodiment, a notch could be provided in wire  58  adjacent flag end  59 , which presents an alternative tip-up mechanism. In this alternative, bobber stop  30  could be positioned to either engage in set slot  52  and operate as described herein above, or alternatively engage directly in this notch in flag end  59 , causing flag  32  to bob similar to the way a standard bobber bobs when a fish strikes. Consequently, the scope of the invention is set forth and particularly described in the claims herein below.