Variable displacement fishing device that responds to fluctuating drag force in fluids at strike

1 . An apparatus for fishing, wherein the apparatus comprises:

a hollow housing with a proximal end terminating in a means of attachment to a fishing line, and an opposite, distal end which terminates in an opening into an interior of said hollow housing;

a displacement element located at least partly inside said interior of said hollow housing, wherein said displacement element has a first end located inside said interior of said hollow housing that attaches to said housing, and an opposite, second end that is attached to a leader and either i) lies within said interior of said hollow housing or ii) is located outside of said hollow housing, wherein said displacement element partially or wholly extends to allow a suction of a fish strike to pull a bait into a mouth of the fish, said displacement element comprising a spring having a spring rate of between 0.11 Newtons/inch and 0.47 Newtons/inch;

wherein said leader has a means for attachment to a pseudo-leader, fishing line, or fishing bait; wherein said hollow housing includes a top piece and a bottom piece, said hollow housing has at least one flow port that is spaced from said opening and that runs from an outside of the housing into said interior of said hollow housing; and wherein said at least one flow port is defined between said top piece and said bottom piece and is defined by a concave surface of said bottom piece that extends radially outwardly beyond said top piece, relative to a central axis of said hollow housing.

2 . The apparatus of claim 1 , wherein said displacement element is a stainless-steel extension spring wholly retained within the hollow housing.

3 . The apparatus of claim 1 , wherein said second end of said displacement element protrudes out from said open end of said housing before attaching to said leader.

4 . The apparatus of claim 1 , further comprising a means to stop said displacement element from over-extending.

5 . The apparatus of claim 1 , wherein said opening into said interior of said hollow housing is covered by a wear-sleeve.

6 . The apparatus of claim 1 further comprising a means for pre-tensioning said displacement element.

7 . The apparatus of claim 6 wherein said pre-tensioning means is selected from one of: a friction sleeve; a friction tube; a friction bead; or a spacer which attaches to said leader and tensions said displacement element prior to use of the apparatus.

8 . The apparatus of claim 1 , wherein said hollow housing has a length that is at least two times larger than an un-extended length of said displacement element.

9 . The apparatus of claim 1 , wherein at least a portion of said hollow housing is transparent, and said displacement element is visible through said portion of said hollow housing.

10 . The apparatus of claim 1 , wherein at least a portion of said hollow housing is marked, shaped, or inscribed with distance measurement indicia which indicate a degree to which said displacement element has been extended.

11 . The apparatus of claim 1 , wherein said means for attachment to a pseudo-leader, fishing line, or fishing bait are selected from the group consisting of: a swivel-joint.

12 . An apparatus for fishing, wherein the apparatus comprises:

a hollow housing with a proximal end terminating in a means of attachment to a fishing line, and an opposite, distal end which terminates in an opening into an interior of said hollow housing;

a displacement element located at least partly inside said interior of said hollow housing, wherein said displacement element has a first end located inside said interior of said hollow housing that attaches to said housing, and an opposite, second end that is attached to a leader and either i) lies within said interior of said hollow housing or ii) is located outside of said hollow housing, wherein said displacement element partially or wholly extends to allow a suction of a fish strike to pull a bait into a mouth of the fish;

wherein said leader has a means for attachment to a pseudo-leader, fishing line, or fishing bait; and

wherein said displacement element comprises a spring having a spring rate accommodating a drag force range of between 0.02 Newtons generated by a fishing bait trolled at 1.0 mph to 10 Newtons generated by said fishing bait experiencing 7 mph of relative water velocity at strike; wherein said hollow housing includes a top piece and a bottom piece, said hollow housing has at least one flow port that is spaced from said opening and that runs from an outside of the housing into said interior of said hollow housing; and wherein said at least one flow port is defined between said top piece and said bottom piece and is defined by a concave surface of said bottom piece that extends radially outwardly beyond said top piece, relative to a central axis of said hollow housing.

13 . A method of catching fish, said method comprising the steps of:

providing the apparatus of claim 1 , the fishing line operably connected to a means of retracting said fishing line, and the fishing bait;

attaching said first end of said hollow housing to said fishing line;

attaching said leader to said fishing bait;

placing said fishing line, said apparatus, and said fishing bait into water;

allowing a fish to strike at said fishing bait; and

operating said means of retraction to retract said fishing line.

14 . The method of claim 13 , wherein said means for attachment to a pseudo-leader, fishing line, or fishing bait partially or wholly extends relative to said hollow housing to allow the suction of the fish strike to pull said fishing bait into the mouth of the fish.

15 . The method of claim 13 further comprising the steps of:

providing a means of pre-tensioning said displacement element; and

using said means of pre-tensioning said displacement element before placing said apparatus in water.