Expandable fish lure

An expandable fish lure adapted to be coupled to a fishing line includes a pair of substantially flat sides having a fish lure appearance in order to attract fish. The lure is formed of a unitary, U-shaped member for biasing said side members apart, each side carrying a fish hook at one extremity thereof. Locking means, in the form of an axial shaft extending between the two sides and a pair of locking plates at the extremities of the sides, cooperate together against the tension of the biasing means until such time as the axial shaft is pulled through the two locking plates to permit release of the sides thereby causing one of the fish hooks to expand away from the shaft.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to fishing lures and hooking arrangements, 
and in particular relates to multiple hook arrangements which are designed 
to expand under tension. 
2. Description of the Prior Art 
A number of expandable fish hook assemblies for lures have been devised and 
disclosed in the prior art. 
In U.S. Pat. No. 2,644,264, Heki discloses a double fish hook arrangement 
having a looped biasing spring between the sides and having a "mouse trap" 
type lock release to permit the sides to expand. The release includes a 
shaft which spreads between the two hooks when in the open position. In 
the closed position, the arrangement taught by Heki employs a ring which 
holds the shaft in place, the shaft having a hook on one end which engages 
one of the sides. 
In U.S. Pat. No. 2,759,289, Haape discloses a combined fish-hook and trap 
arrangement employing an axial shaft which is spring-loaded, the shaft 
having a curved cam plate attached at the end of the shaft and between the 
two fish-hook sides, such that axial movement of the shaft causes the cam 
plate to force the two fish-hook sides in an expansion position. 
In U.S. Pat. No. 3,410,019, Landi discloses another camming arrangement, in 
which the forward extremities of the fish hooks are pivoted, and the 
barbed ends of the fish hooks cross, with a camming ring attached between 
the fish hooks and coupled to the fishline, such that tension on the lure 
causes the cam ring to slide through the lure and force the two hooks 
outwardly with respect to the lure. A somewhat similar arrangement is 
taught by Wolf in U.S. Pat. No. 2,597,832. 
Tomsello, in U.S. Pat. No. 3,081,572, discloses a weedless fish lure 
employing another form of the "mouse trap" type release. 
In U.S. Pat. No. 1,812,906, Swearingen discloses an artificial lure having 
a pair of fish hooks joined together by a looped spring, and being held 
together by a catchpin. Movement of the looped spring toward the front of 
the lure responsive to tension of the lure on the line causes the fish 
hooks to disengage from the catchpin, and spring outward into an expansion 
position. 
Burnett, in U.S. Pat. No. 3,026,645, discloses an expandable fish hook 
assembly, in which the fish hooks are beveled out of a cylindrical 
container responsive to axial drag on the fish hooks with respect to the 
cylindrical storage tube. 
Arrangements like that described in the prior art patents referred to above 
tend to be unduly complex and expensive, and are difficult to reload; that 
is, are difficult to return to the nonexpanded condition. It is therefore 
desirable to employ a simple release mechanism for such fish lure 
assemblies, but which release permits the use of relatively flat and wide 
sides, such that a true artificial fish lure appearance can be obtained 
with the device. Typical with such prior art arrangements as those 
described above, those arrangements which have an artificial lure 
appearance are relatively complex and are difficult to load into the 
loaded position. However, the relatively simple arrangements, such as 
those disclosed in the Haape and Heki patents are not easily adapted to 
the artificial lure structures. 
SUMMARY OF THE INVENTION 
The present invention contemplates an expandable fish lure adaptable to be 
coupled to a fishing line, and comprises a pair of substantially flat 
sides having a fish lure appearance in order to attract fish. Means are 
coupled to both of the sides for biasing the side members apart. A pair of 
fish hooks are provided, each carried by one of the sides at one extremity 
thereof. Locking means with the assembly includes a rigid shaft coupled to 
the fishing line, the locking means providing means for locking the sides 
together against the tension of the biasing means, the locking means 
further including means for getting release of the sides responsive to 
movement of the shaft axially with respect to the fishing line. 
In a preferred embodiment of the present invention, the two sides in the 
biasing means comprise a unitary, U-shaped member having substantially 
flat sides and a bridge therebetween having a hole therein, the member and 
the bridge formed of a springy material having an elastic memory. By way 
of example, the unitary, U-shaped member may comprise a stainless steel 
material, or alternatively a polyresinous material having an elastic 
memory, such as nylon. 
In the preferred embodiment of the present invention, the locking means 
includes first and second locking plate coupled respectively to the first 
and second sides of the lures. Each locking plate includes a hole adapted 
to receive the shaft, the holes being aligned when the shaft is extending 
therethrough. Preferably, the shaft includes a beveled extremity, and a 
shoulder having a dimension substantially greater than the upper locking 
plate, in order that the movement of the shaft out of the two holes in the 
first and second locking plates is restricted. 
Further in accordance with the preferred embodiment of the present 
invention, each locking plate is joined to the respective side of the lure 
with the corresponding fish hook by way of a common fastener.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The preferred embodiment will now be described in detail with reference to 
FIGS. 1-4. 
With reference first to FIGS. 1 and 2, the expandable fishing lure of the 
present invention, which is referred to generally by the reference numeral 
10, comprises a unitary, U-shaped fish lure member 11 defining two flat 
sides and a biasing bridge therebetween, with the bridge including a hole 
20 therein. The unitary, U-shaped member 11 may be shaped like a bass 
lure, or similar lure. However, it will be understood by those skilled in 
the art that the term "flat side" as employed in the above description is 
intended to mean a relatively wide lure body, and is not intended to be 
limited to the specific thin-gauge metal structures shown in the drawings. 
The U-shaped fish lure member 11 is formed of a springy material having an 
elastic memory, such as spring steel or nylon. The bridge between the two 
extending sides of the fish lure member 11 is constructed such that they 
are biased apart by the tension of the bridge, when not being restrained 
in the manner described in greater detail below. 
Reference is now made to FIGS. 2, 3, and 4. The lure 10 includes lower and 
upper locking plates 14, 15, each having a hole therein (note FIG. 2). 
Each locking plate 14, 15 comprises a flat-gauge metal or similar material 
which is joined to the inside of the respective one of the sides of the 
fish lure member 11, by respective fasteners 19a and 19b, as described in 
greater detail below. 
The lure 10 is further provided with two fish hooks 12, 13, each fish hook 
being joined to a respective side of the fish lure member 11 by a 
corresponding fastener 19a, 19b and is commonly joined to the respective 
side with the associated locking plate 14, 15 as is shown in the drawing. 
Although the type of fastener used with this construction is not 
essential, a rivet or brad is preferable. 
Reference to FIGS. 2, 3, and 4 is continued. The lure 10 further includes 
an axial shaft 16 extending through the hole 20 in the bridge of the fish 
lure member 11, and axially between the two sides of that member. The 
shaft 16 includes a shoulder 17 between the first and second locking 
plates 14, 15, the diameter of the shoulder 17 being sufficient to prevent 
the extremity of the shaft from moving through the hole in the second 
locking plate 15. The shaft 16 further includes a reduced thickness area 
adjacent the extremity thereof, forming a bevel 18 which permits the 
extremity of the shaft 16 to move easily into and out of the hole in the 
lower locking plate 14. Further, the shaft 16 includes an eyelet at the 
other extremity thereof, permitting the lure 10 to be joined to a 
conventional fishing line. 
Operation of the lure 10 will now be described with reference to FIGS. 2, 
3, and 4. 
Initially the lure 10 is attached to a fishing line by threading the line 
through the eyelet in the shaft 16. The two sides of the U-shaped fish 
lure 11 are pushed together, such that the two holes in the locking plates 
14, 15 are axially aligned. The shaft 16 is then pushed downward, so that 
the beveled extremity 18 thereof may be extended through the hole in the 
locking plate 14. This sets the lure 10 in the closed position. The 
fisherman can then pass the lure as desired during normal fishing 
activities. 
When a sufficient tension is exerted between the shaft 16 and the fish lure 
member 11, as when a fish strikes the hooks 12, 13, the shaft 16 moves 
axially the hole 20 in the bridge portion of the fish lure member 11. At 
the same time, the beveled extremity 18 of the shaft 16 moves out of the 
hole in the first locking plate 14. This releases one side of the lure 
member 11, causing that side to spring away from the other side, by virtue 
of the biasing characteristics of the material from which the member 11 is 
formed and the shape of the bridge portion. The expansion of the lure 10 
increases the likelihood that one of the hooks 12, 13 will be caught 
within the fish's mouth in the desired manner.