Fishing rod having a water dispersion surface to reduce drag on fishline

The present disclosure concerns a fishing rod which reduces resistance between a fishline and a tubular member of the fishing, thereby allowing the fishline to be transported through the tubular member smoothly. The tubular member incorporates a diffusion property on its interior surface for spreading waterdrops into a thin film of water.

BACKGROUND OF THE INVENTION 
a) Field of the Invention 
The invention concerns a fishing rod, in particular, an intra-line fishing 
rod which is structured such that a fishline can extend through a rod main 
body. The present invention also relates to a fishline. 
A conventional intra-line fishing rod includes a fishing rod main body 
formed of a tubular member through which a fishline extends. On the other 
hand, an ordinary fishing rod includes fishline guides on the outside of a 
fishing rod main body through which a fishline passes. The intra-line 
fishing rod eliminates the possibility that the fishline can become 
tangled in the fishline guides, consequently operation of the intra-line 
fishing rod is improved over that of the ordinary fishing rod. 
Conventional intra-line fishing rods have the disadvantage when winding a 
fishline out of the water the fishline brings drops of water inside the 
tubular member of the fishing rod main body. The waterdrops become 
attached to the interior surface of the fishing rod main body, 
consequently the fishline cannot be moved smoothly through the fishing rod 
main body due to the resistance of the waterdrops. Clearly, this impairs 
the operation of conventional intra-line fishing rods. 
b) Description of Related Art 
In order to address this problem, Japanese Unexamined Patent Publication 
No. Hei. 5-268858 discloses an intra-line fishing rod in which the 
interior surface of a tubular fishing rod main body includes thereon a 
resin layer containing fluoro-resin particles. Such an intra-line fishing 
rod improves the ability to repel water off the interior surface of the 
fishing rod main body by easing movement of waterdrops. 
An intra-line fishing rod having the aforementioned resin layer facilitates 
movement of the waterdrops attached thereto, but cannot remove the 
waterdrops completely. Therefore, some of the waterdrops remain scattered 
on the interior surface. In this case, a "contact" angle .theta. between 
the interior surface and a line tangent to the exterior of a waterdrop (at 
the junction of the surface and the waterdrop) is in the range of 
90.degree. to 110.degree.. Resistance to passage of the fishline through a 
fishing rod main body with waterdrops scattered on an interior surface 
having a resin layer is not always small when compared with a fishing rod 
that does not include the resin layer. Therefore, in conventional 
intra-line fishing rods, the fishline cannot be passed through the fishing 
rod main body to a satisfactory degree. 
SUMMARY OF THE INVENTION 
An object of the present invention is to eliminate the aforementioned 
disadvantage of conventional intra-line fishing rods. Accordingly, the 
present invention provides a fishing rod which reduces resistance to 
passage of a fishline through a fishing rod main body, thus enabling the 
fishline to pass smoothly through the fishing rod main body. Another 
object of the present invention is to provide a fishline which can be 
inserted and passed smoothly through a tubular fishing rod main body. 
The present inventors have determined that the resistance of the water 
drops can be reduced by incorporating a diffusion property on the interior 
surface of a fishing rod main body, as opposed to a conventional fishing 
rod main body wherein the resistance of the waterdrops is reduced by 
applying a water repellent substance to the interior surface. 
According to a first aspect of the present invention, a fishing rod is 
provided which includes a tubular member through which a fishline extends, 
and a diffusion property created on the interior surface of the tubular 
member. 
According to a second aspect of the present invention, a fishline is 
provided which incorporates a diffusion property. 
In the present invention, the term "diffusion" refers to the ability to 
spread water in a thin film. In particular, a diffusion property according 
to the present invention reduces the contact angle .theta. to 80.degree. 
or less, and preferably 60.degree. or less. The contact angle .theta. is 
illustrated in FIG. 5 between the water W and contact surface S. 
In the first and second aspects of the present invention, the diffusion 
property may be obtained by concomitantly forming a diffusion layer on the 
interior surface of the tubular member or with the body of the fishline. 
Alternatively, a subsequent treatment may apply a diffusion layer to the 
interior surface of the tubular member or to the body of the fishline. 
The diffusion property can be achieved by producing a thin metal layer 
according to a wet-type or dry-type plating method, and then oxidizing the 
surface of the thin metal layer to produce an oxidized metal layer. For 
example, a thin aluminum layer may be plated onto the interior surface of 
the tubular member or inside the fishline main body, with a subsequent 
Alumirite treatment oxidizing the aluminum layer. 
The diffusion property can also be achieved by roughening the interior 
surface of the tubular member or inside the fishline main body to increase 
the surface area thereof. Examples of such roughening techniques include 
sand blasting, barrel polishing, honing, corona discharge, plasma or spark 
treatments, as well as chemical treatments using acid(s) or alkali(s). 
Further, the diffusion property can be achieved by treating the interior 
surface of the tubular member or inside the body of the fishline with 
surface active agents. The diffusion property can yet further be achieved 
by creating a diffusion layer in addition to applying a diffusion 
treatment onto the surface of the layer. 
The present inventors have also determined that the resistance to water 
drops can be reduced by using a stronger water repellent than is 
conventionally and generally used. That is, applying a super-repellent to 
the interior surface of the fishing rod body. 
In particular, according to this third aspect of the present invention, 
there is provided a fishing rod which includes a tubular member through 
which a fishline can extend, and a super-repellent layer created on the 
interior surface of the tubular member. 
According to a fourth aspect of the present invention, the body of a 
fishline includes a super-repellent layer formed thereon. 
The term "super-repellent" used in the third and fourth aspects of the 
present invention refers to the property of a material which, when the 
material is wetted with water, does not allow the normal formation of 
waterdrops thereon but instead forms water balls which are easily removed, 
or allows only part of the water to remain thereon in the form of minute 
drops of water. In particular, a surf ace having a super-repellent 
property has a contact angle .theta. of 120.degree. or greater, preferably 
in the range of 150.degree. to 180.degree.. 
In the third and fourth aspects of the present invention, the 
super-repellent layer can be formed by a dispersed plating method in which 
metal such as nickel, nickel alloy, copper, copper alloy, tin, tin alloy 
or the like is used as mother material, and fluoride particles or fluoride 
fibers are dispersed in the mother material to produce a plating solution. 
In addition to fluoride particles or fluoride fibers, it is also possible 
to incorporate graphite fluoride particles, polytetrafluoroethylene fine 
particles, and the like having a mean molecular weight on the order of 
8,000 to 10,000. 
The super-repellent property can be achieved when the proportion of 
fluorine atoms in a layer exceed approximately 20%, with respect to the 
total number of atoms existing in the layer. The super-repellent layer may 
also be formed by a method in which the fluorine atoms exist on the 
surface of the layer in relatively larger numbers. Examples of such 
methods include a first method in which epoxy resin or acryl-urethane 
resin are mixed with minute particles (having a particle diameter on the 
order of 1 .mu.m or less) then a thin coating (having a thickness on the 
order of 10 .mu.m) is allowed to dry, and a second method in which tape 
including a base member having an adhesive layer and the above-mentioned 
epoxy resin or acryl-urethane resin uniformly attached onto the tape base 
member are bonded onto the interior surface of the tubular member or onto 
the body of the fishline, after which only the tape base member is 
removed. 
The thickness of the diffusion property or super-repellent property of the 
tubular member in the fishing rod according to the first and third aspects 
is preferably as large as possible to take into account wear resistance 
(preferably, in the range of 10 to several hundred .mu.m). If the 
thickness of the diffusion property of the tubular member is less than 10 
.mu.m, then a sufficient diffusion or super-repellent effect cannot be 
obtained. On the other hand, the thickness of the diffusion or 
super-repellent property of the fishline according to the second and 
fourth aspects is preferably in the range 1 to several .mu.m. If the 
thickness of the diffusion or super-repellent property of the fishline is 
less than 1 .mu.m, then it is not likely the layer will be able to perform 
its diffusion or super-repellent function to a sufficient degree. 
Additionally, If the thickness is in the range of several tens of .mu.m, 
then the weight of the fishline becomes too heavy. 
Suitable materials for the tubular member of a fishing rod main body 
include a mixture of reinforcing fiber such as carbon fiber, glass fiber, 
aramid fiber, alumina fiber or the like within the matrix of a 
thermosetting resin such as an epoxy resin or a thermoplastic resin (e.g. 
polyether-ether ketone resin or polyether-imide resin). Forming the 
tubular member may also include heating and pressurizing the 
above-mentioned materials until hardened. 
Although the first and third aspects of the present invention have been 
described with respect to an intra-line fishing rod in which the tubular 
member is used as the fishing rod main body, the present invention is also 
applicable to fishing rod guide members attached to the outside of the 
fishing rod main body. The guide members may be formed of synthetic resin, 
metal or ceramics. 
Materials for the body of the fishline, according to the second and fourth 
aspects of the present invention include polyamide resin such as nylon, 
polyethylene resin, polyether resin or the like. 
Inherently, using the fishing rod according to the first or third aspect in 
combination with the fishline according to the second or fourth aspect, 
the fishline can be transported with respect to the fishing rod even more 
smoothly. 
The fishing rod according to the present invention comprises a hollow 
tubular member with a fishline extending therethrough and a diffusion 
property formed on the interior surface of the tubular member. 
The diffusion property on the interior surface of the tubular member causes 
drops of water brought inside the tubular member by a fishline to be 
spread as a thin film on the interior surface. This reduces the number of 
waterdrops inside the tubular member. That is, the diffusion property 
increases the cross-section area inside the tubular member which avoids 
contact between the fishline and any waterdrops. Therefore, as the 
fishline passes through the tubular member, it is difficult for any 
waterdrops to become attached to the fishline. 
Also, when the fishline contacts the interior surface of the tubular 
member, the fishline passes through a thin film of water. There is less 
resistance between the fishline and the film than between the fishline and 
waterdrops scattered throughout the inside of the tubular member. 
Consequently, the fishline can be transported through the fishing rod main 
body smoothly so as to improve the operation of the fishing rod. 
The fishline according to the present invention comprises a diffusion 
property provided with the fishline. 
The diffusion property created for the fishline according to the present 
invention readily spreads drops of water into a thin film. For this 
reason, as in the above-mentioned cases, it is possible to increase the 
cross-section area inside the tubular member which allows the fishline to 
extend without contact with any waterdrops. Also, even if the fishline 
contacts the interior surface of the tubular member, the resistance 
therebetween is reduced due to the thin water film formed on the surface 
of the fishline. Further, when the fishline extends inside the tubular 
member, the thin film of water attached to the fishline prevents the 
fishline from adhering to the interior surface of the tubular member. 
As a result of the present invention, the fishline can be payed out and 
taken up smoothly. 
The fishing rod according to the present invention comprises a hollow 
tubular member allowing a fishline to extend therethrough and a 
super-repellent layer formed on the interior surface of the tubular 
member. 
The super-repellent layer on the interior surface of the tubular member 
causes drops of water brought inside the tubular member by a fishline to 
form big water balls which are easily removed from the tubular member. 
This means it is possible to remove the waterdrops that are the cause of 
the resistance on the fishline. As a result of this, the fishline can be 
extended through the fishing rod main body smoothly thereby improving the 
operation of the fishing rod. 
The fishline according to the present invention comprises a fishline and a 
super-repellent layer formed thereon. 
The super-repellent layer on the fishline according to the present 
invention ensures drops of water are prevented from becoming attaching to 
the fishline. For this reason, the fishline does not bring waterdrops 
inside the tubular member therewith, and thereby prevents waterdrops from 
becoming attaching to the interior surface of the tubular member. As a 
result, the fishline can be payed out and taken up smoothly.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The following description of each aspect of the present invention is with 
reference to the accompanying drawings. 
FIG. 1 shows a top rod 10 including a tip guide 11 at one end (the smaller 
diameter end) The other end (the larger diameter end) of the top rod 10 
cooperatively attaches to the smaller diameter end of a middle rod 12. The 
larger diameter end of the middle rod 12 cooperatively attaches to the 
smaller diameter end of a base rod 13. 
The base rod 13 includes a fishline insertion guide 14. The base rod 13 
also includes a reel fixing device 15 which is disposed between the 
fishline insertion guide 14 and the larger diameter end of the base rod 
13. A reel 17 supporting a spool of fishline 16 thereon is fixed by the 
reel fixing device 15 to the base rod 13. The base rod 13 further includes 
a rod bottom part 18 at the larger diameter end thereof. 
The fishline 16 is inserted into the fishing rod through the fishline 
insertion guide 14 and exits the fishing rod from the tip guide 11. 
FIG. 2 shows a tubular member 20 which is a portion "A" of the top rod 10. 
On the interior surface of the tubular member 20, there is formed a 
diffusion layer 21 which provides a diffusion property. The diffusion 
layer 21 can be formed with an aluminum layer on the interior surface of 
the tubular member which then receives an Alumirite treatment to oxidize 
the aluminum layer. The structure shown in FIG. 2 is not limited only to 
the top rod 10 but can also be incorporated in the middle rod 12 and the 
portions of the base rod 13 between the smaller diameter end and the 
fishline insertion guide 14. 
The intra-line fishing rod according to the present invention provides a 
diffusion layer formed on the interior surface of the tubular member so 
that drops of water which have been carried inside the tubular member by 
the fishline are readily turned into a thin water film. Consequently, the 
cross-section area inside the tubular member is increased thereby allowing 
the fishline to extend therethrough without contacting the waterdrops. 
When the fishline passes through the central portion of the tubular 
member, the waterdrops are prevented from becoming attached to the 
fishline. Further, when the fishline contacts the interior surface of the 
tubular member, the fishline encounters a thin water film which offers 
minimal resistance (only the viscous resistance of water). 
A fishline passing through a thin water film encounters less resistance 
than when the fishline passes through scattered waterdrops. The difference 
depends on the number of times the fishline passes through the interface 
(designated 33 in FIG. 3) between air and water. The fishline encounters 
resistance each time it passes through an interface between air and water. 
When many waterdrops are scattered across the interior surface, the number 
of times the fishline passes through an interface between air and water 
increases. Correspondingly, the resistance on the fishline is increased. 
On the other hand, when the fishline passes through a thin water film, the 
number of times the fishline passes through an interface between air and 
water is minimal, therefore the resistance to passage of the fishline is 
minimal. 
The present invention allows the fishline to extend smoothly through the 
fishing rod, thereby improving the operation of the fishing rod. 
Conventional Example: 
A conventional intra-line fishing rod, i.e. without a diffusion layer 
according to the present invention, is shown in FIG. 3. A waterdrop 31a 
attached to the interior surface of a tubular member 30 and a waterdrop 
31b attached to a fishline 32 are attracted to each other due to surface 
tension. When the fishline 32 is moved, the fishline 32 must also pull the 
waterdrops 31a,31b such that resistance to movement of the fishline 32 
increases. The increased resistance to movement of the fishline causes a 
decrease in the ability to operate the fishing rod. 
FIG. 4 illustrates the comparative results of an intra-line fishing rod 
according to the present invention and the above conventional example. In 
particular, the relationship between moving speed of the fishline and 
resistance on the fishline (as measured with a tension meter) for each 
fishing rod is examined. The measured values shown in FIG. 4 are the mean 
values of five tests. 
The intra-line fishing rod according to the present invention (plotted with 
triangles) demonstrates resistance on the fishline is substantially 
consistent and less than of the conventional example (plotted with 
circles) at all moving speeds of the fishline. The resistance on the 
fishline in the conventional example was especially greater at the slower 
moving speeds of the fishline, such as when the fishline is taken up or 
when dropping a light sinker (fishline terminal tackle) into the water. 
FIG. 4 also indicates in both the present invention and the conventional 
example, that resistance on the fishline tends to decrease as the moving 
speed of the fishline increases. This is because as the moving speed of 
the fishline increases, the reactive forces to the forces which tend to 
impede movement of the fishline increase, and the resistance on the 
fishline decrease. 
FIG. 6 is an enlarged section view of a portion of another embodiment of 
the present invention corresponding to the "A" portion of the top rod 10 
shown in FIG. 1. A tubular member 20 has on its interior surface a 
super-repellent layer 21' which has a super-water-repellent property. The 
super-repellent layer 21' is formed according to a dispersed plating 
method in which nickel is used as a mother material and graphite fluoride 
particles are dispersed in the nickel to produce a plating solution. The 
structure shown in FIG. 6 is applicable not only to the top rod 10, but 
also to the middle rod 12 and the portions of the base rod 13 between the 
smaller diameter end and the fishline insertion guide 14. The 
super-repellent layer 21' causes drops of water to become balls or beads 
of water that are readily removed. 
The intra-line fishing rod of the present invention having a 
super-repellant layer 21' formed on the interior surface of the tubular 
member 20, causes drops of water that have been brought inside the tubular 
member 20 by the fishline to be easily turned into balls or beads of water 
which are readily discharged from the tubular member 20. As a result, very 
few waterdrops remain inside the tubular member 20, thereby eliminating 
resistance caused by the waterdrops and allowing the fishline to be 
transported smoothly so as to improve operation of the fishing rod. 
In the above-mentioned embodiments of the present invention, it has been 
assumed that the fishline 16 is formed of nylon having an outside diameter 
approximately 0.235 mm upon which no additional treatment has been 
applied. However, if the surface of the fishline is roughened by a 
chemical treatment using acid or alkali so as to create a diffusion 
property, or a super-repellent layer is formed on the fishline, then the 
fishline can be transported more smoothly through a fishing rod. 
Also, the description of the aforementioned embodiments of the present 
invention has been given with reference to an intra-line fishing rod in 
which the tubular member is the body of the fishing rod itself. However, 
the advantages of the present invention can also be incorporated into 
tubular members serving as guides provided along the exterior surface of 
fishing rod. Essentially, the advantages of the present invention are 
equally applicable to all tubular members having a fishline extending 
therethrough. In addition, the diffusion layer or the super-repellent 
layer of the invention may be provided on an exterior surface of the 
fishing rod.