Method of making fishing rod and fishing rod made by the method

A method of making a pipe-like member such as a fishing rod and a golf club is disclosed. According to the method, a tape-like prepreg is formed by overlaying each other a first fiber layer comprised of fibers aligned along a longitudinal direction of the layer and a second fiber layer comprised of fibers aligned in a direction substantially normal to the fiber alignment direction of the first fiber layer. Then, the tape-like prepreg is wound about a mandrel with a turn of the prepreg being widthwise overlapped with an adjacent turn of the prepreg. Thereafter, the assembly is sintered.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a method of making a pipe-like member 
incorporating a reinforcing fiber layer for use in e.g. a fishing rod, a 
shaft of a golf club or the like and the invention also relates to such 
pipe-like member made by the method. 
2. Description of the Related Art 
Conventionally, a pipe-like member of the above-described type 
incorporating a reinforcing fiber layer is formed by winding about a 
mandrel a plurality of prepreg sheets each comprised of fibers aligned in 
a predetermined direction in such a manner as to arrange the fiber 
extending directions of the sheets normal to each other and then sintering 
this assembly. 
With the above-described manufacturing process of the pipe-like member, the 
method requires that the prepreg sheets be cut in advance according to a 
desired diameter and length of the pipe-like member to be made. In short, 
according to this conventional method, the prepreg sheets must be cut in 
advance and this cutting of the prepreg sheets must be done in accordance 
with the dimensions of the target pipe-like member. 
In winding the prepreg sheets about the mandrel, it is desired that the 
winding operation take place with applying a significant force (e.g. a 
tensional force) between adjacent prepreg layers. However, because the 
prepreg in the form of sheet has a large contact area, it is difficult to 
apply such large force to the adjacent sheets. 
Further, in the course of the winding operation of the prepreg sheets, an 
air gap may be formed between the wound layers. Then, if the assembly is 
sintered with such air gap, the air layer remains as voids which 
deteriorates the strength of the finished pipe-like member. 
The primary object of the present invention is to provide an improved 
method of making a pipe-like member, which method requires fewer steps 
than the conventional method regardless of the diameter and length of the 
member to be made yet can provide the member with higher strength. 
SUMMARY OF THE INVENTION 
For accomplishing the above-noted object, a method, relating to the present 
invention, of making a pipe-like member, comprises the steps of: 
forming a tape-like prepreg by overlaying each other a first fiber layer 
comprised of fibers aligned along a longitudinal direction of said layer 
and a second fiber layer comprised of fibers aligned in a direction 
substantially normal to said fiber alignment direction of the first fiber 
layer; 
winding said tape-like prepreg about a mandrel with a turn of the prepreg 
being widthwise overlapped with an adjacent turn of the prepreg; and 
sintering the assembly obtained from said steps. 
Functions and effects of the above features will be described next. 
The method can be embodied as shown in FIGS. 1 through 4 for example. As 
the prepreg P in the form of a tape is wound about a mandrel 3, with 
application of a tension to this prepreg being wound, it is possible to 
obtain a sufficient pressure contact force for the prepreg even if the 
applied tension is relatively small. Further, since the prepreg tape has a 
smaller width than the prepreg sheet used in the convention, an air gap 
will hardly be formed between the adjacent turns of the prepreg tape. 
Moreover, even if such air gap should be formed, thermal expansion of the 
air gap in the course of the sintering operation will advantageously cause 
the air content to escape along the width of the tape out of the prepreg 
P. 
Incidentally, although it is conceivable to cut a cloth (fiber) sheet type 
prepreg P into a tape-like shape, as shown in FIG. 8 provided for 
comparison, even if a significant pressure is applied to this prepreg in 
the course of the sintering operation, air gaps tend to be formed as voids 
in the fiber tissues and between the tissue and the mandrel. Further, as 
shown in FIG. 7, this construction is inferior to that afforded by the 
present invention because of lower density of the fiber tissue. 
That is, according to the present invention, the pipe-like member is formed 
by winding of the prepreg in the form of tape, such that it becomes 
possible to make pipe-like members of various diameters and/or lengths 
only through selection of the configuration of the mandrel about which the 
prepreg tape is wound. Further, the method of the present invention can 
effectively prevent generation of voids because sufficient pressure 
contact force is readily available in the course of the winding step 
without using any special means for providing such force. 
Consequently, the invention has achieved its primary object of providing an 
improved method of making a pipe-like member, which method requires fewer 
steps than the conventional method regardless of the diameter and length 
of the member to be made yet can provide the member with higher strength. 
In particular, as shown in FIG. 5, with the method of the invention, there 
are formed steps on the outer periphery of the finished pipe-like member, 
which is suitable for use as a fishing rod because the steps serve as 
anti-slip means for an angler's hand gripping this rod. 
In case a traverse winding portion is to be formed on a longitudinally 
intermediate portion of the fishing rod as shown in FIG. 6, a different 
prepreg tape than that used for forming the rod body is wound by a greater 
turning pitch, so that unevenness is formed on the outer periphery of the 
rod. This unevenness is effective for restricting sticking of a wet 
fishing line to the rod surface. 
Further, and other objects, features and effects of the invention will 
become more apparent from the following more detailed description of the 
embodiments of the invention with reference to the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Preferred embodiments of a method of making a pipe-like member and a 
pipe-like member made by the method relating to the present invention will 
now be described in detail with reference to the accompanying drawings. 
FIGS. 1 through 5 illustrate a method according to one preferred embodiment 
of the present invention for making a pipe-like member A for use in e.g. a 
fishing rod. 
As shown in FIGS. 1 and 2, this method employs a first fiber layer 1 
comprised of fibers aligned along a longitudinal direction of the layer 
and a second fiber layer 2 comprised of fibers aligned in a direction 
substantially normal to the fiber alignment direction of the first fiber 
layer 1, with the first fiber layer and the second fiber layer being 
overlaid on each other. Then, this assembly is impregnated with a 
thermosetting resin such as an epoxy resin to be formed into a tape-like 
prepreg P. 
This prepreg P having a width W of 15 mm is so prepared that the first 
fiber layer 1 has a thickness T1 of 0.03 mm and the second fiber layer 2 
has a thickness T2 of 0.2 to 0.7 mm, respectively. Further, these layers 
1, 2 are formed of such fiber material as glass fiber, carbon fiber or the 
like. 
Then, as shown in FIG. 3, the above-described prepreg P is wound about a 
mandrel 3 with a turn of the prepreg being widthwise overlapped with an 
adjacent turn of the prepreg. 
In the course of this winding operation, an appropriate measure such as 
application of a braking force to a rotary support shaft 4 for the tape is 
taken so as to cause the prepreg tape P to contact the mandrel 3 with an 
appropriate amount of contact pressure. 
Thereafter, as illustrated in FIG. 4, on an upper surface of the wound 
prepreg P, a heat-contracting type tape 5 is wound and then this assembly 
is sintered. 
In the course of the above sintering operation, the thermal contraction of 
the tape 5 compresses the prepreg 5 and also the application of the heat 
serves to integrate the resin of the overlapped turns of the prepreg P. 
Then, the mandrel 3 is withdrawn from the assembly and the tape 5 is 
removed. And, the opposed terminal ends of this assembly are cut away to 
provide a pipe-like member A having a cross section shown in FIG. 5. 
FIG. 6 shows a construction obtained according to a method of a further 
embodiment. In this construction, the prepreg tape is wound in a traverse, 
i.e. cross pattern to obtain a better hand-gripping performance. 
A further embodiment of the method of the invention will be described next 
with reference to FIGS. 9 through 13. 
(a) From a prepreg sheet, there are cut a plurality of prepreg strips each 
having a predetermined width shorter than a length of an entire fishing 
rod as a pipe-like member to be made. Then, these strips are bonded to 
each other to obtain a prepreg tape base 12. The reinforcing fiber forming 
the prepreg has its extending direction aligned with the width of the tape 
base 12. 
(b) From the prepreg sheet, there are cut a plurality of further prepreg 
strips each having a predetermined width shorter than the width of the 
tape base 12. Then, these prepreg strips are bonded to each other to 
obtain a prepreg tape reinforcing element 13. In this case, the 
reinforcing fiber has its extending direction aligned with the 
longitudinal direction of the prepreg tape reinforcing element 13. 
(c) The prepreg tape reinforcing element 13 is laid over the prepreg tape 
base 12 with the element 13 and the base 12 being longitudinally aligned 
to each other to obtain a tape 15 for forming a pipe-like member. 
(d) The pipe-like member forming tape 15 is wound about the mandrel 3 in a 
spiral pattern with the alignment direction of the reinforcing fiber of 
the prepreg tape base 12 being slightly inclined relative to the axis of 
the mandrel 3. In the course of this winding operation, a subsequent 
overlapping portion of the tape 15 is overlapped on a foregoing 
non-overlapped portion of the tape 15. 
(e) Thereafter, the assembly is sintered. 
According to the above-described method, the prepreg sheet is cut into the 
strips each having the width shorter than the length of the entire rod. 
Thus, there will be produced fewer strips having lengths shorter than the 
necessary length. As a result, the method can achieve improvement in the 
yield. Also, the cutting patterns are limited to the two types for the 
prepreg tape base and the prepreg tape reinforcing element, such that this 
method can achieve improvement in efficiency in this respect as well. 
Moreover, in winding the pipe-like member forming tape about the mandrel, 
since this tape has the width shorter than the length of the entire 
pipe-like member, the application of the tension can take place evenly, 
thus effectively restricting generation of voids. Further, the 
multi-layered pipe-like member can be formed by the single step of winding 
the pipe-like member forming tape about the mandrel. 
Consequently, according to this method, the manufacturing costs can be 
reduced due to the improvement in the yield and the generation of voids 
can be very effectively restricted by the use of the relatively narrow 
pipe-like member forming tape which can readily follow the round contour 
of the mandrel. Moreover, this method allows various design changes to be 
readily made depending on the necessity, such as of increasing the 
overlapping amount of the tape at a portion such as the opened terminal 
end of the pipe-like member which portion is more subject to cracking 
while decreasing the overlapping amount at the other portions. 
A method of a still further embodiment of the invention will be described 
next. 
(a) From a prepreg sheet, there are cut a plurality of prepreg strips each 
having a predetermined width W shorter than a length of an entire fishing 
rod as a pipe-like member to be made. Then, these strips are bonded to 
each other to obtain a prepreg tape base 12. The reinforcing fiber forming 
the prepreg has its extending direction aligned with the width of the tape 
base 12. 
(b) From the prepreg sheet, there are cut a first prepreg strip and a 
second prepreg strip both having a predetermined width R shorter than the 
width W of the tape base 12. Then, these first and second prepreg strips 
are bonded to each other to obtain first and second prepreg tape 
reinforcing elements 13, 14. The reinforcing fiber has its extending 
direction aligned with the longitudinal direction of the prepreg tape 
reinforcing elements 13, 14. 
(c) The first prepreg tape reinforcing element 13 is laid over an inner 
peripheral surface of the prepreg tape base 12 and the second prepreg tape 
reinforcing element 14 is laid over an outer peripheral surface of the 
base 12 so that the elements 13, 14 are longitudinally aligned with the 
base 12 and further that the first prepreg tape reinforcing element 13 and 
the second prepreg tape reinforcing element 14 are displaced respectively 
to the opposed ends of the prepreg tape base 12, thereby to form a 
pipe-like member forming tape 15. 
(d) Then, this pipe-like member forming tape 15 is wound about the mandrel 
3 in a spiral pattern with the alignment direction of the reinforcing 
fiber of the prepreg tape base 12 being slightly inclined relative to the 
axis of the mandrel 3. In the course of this winding operation, a 
subsequent overlapping portion B of the tape 15 is overlapped on a 
foregoing non-overlapped portion A of the tape 15. 
(e) Thereafter, the assembly is sintered. 
According to the above-described method, at the lowermost layer of the 
multi-laid assembly, the extending direction of the reinforcing fiber is 
aligned along the peripheral direction of the pipe-like member so as to 
increase resistence against cracking. Further, at the upper layers of the 
assembly, the extending directions of the reinforcing fibers of these 
layers are oriented to perpendicularly cross each other so as to increase 
the strength against crushing. Accordingly, this method can eliminate the 
common practice of affixing a reinforcing pattern to a specific limited 
area(s) in the inner layer of the multi-laid prepreg. 
A method of making a rod member 11 as a pipe-like member will be 
specifically described next with reference to FIGS. 9 and 10. 
(a) From a prepreg sheet formed by a unidirectionally aligned reinforcing 
fiber impregnated with a thermosetting resin such as an epoxy rein, there 
is cut a prepreg tape base 12 having a predetermined width W shorter than 
a total length of the rod member 11 to be made. The reinforcing fiber has 
its extending direction aligned with the width of the prepreg tape base 
12. Incidentally, this width W of the prepreg tape base 12 is about 15 mm. 
(b) From the prepreg sheet, there are cut a first prepreg tape reinforcing 
element 13 and a second prepreg tape reinforcing element 14 both having a 
predetermined width R shorter than the width W of the tape base 12. The 
reinforcing fiber has its extending direction aligned with the 
longitudinal direction of the prepreg tape reinforcing elements 13, 14 and 
the fiber has a thickness shorter than the thickness of the prepreg tape 
base 12. 
(c) The first prepreg tape reinforcing element 13 is laid over an inner 
peripheral surface of the prepreg tape base 12 and the second prepreg tape 
reinforcing element 14 is laid over an outer peripheral surface of the 
base 12 so that the elements 13, 14 are longitudinally aligned with the 
base 12 and further that the first prepreg tape reinforcing element 13 and 
the second prepreg tape reinforcing element 14 are displaced respectively 
to the opposed ends of the prepreg tape base 12, thereby to form a 
pipe-like member forming tape 15. Further, in this pipe-like member 
forming prepreg tape 15, there are formed a first overlapping portion A 
where the first prepreg tape reinforcing element 13 is overlapped with the 
second prepreg tape reinforcing element 14 and a second overlapping 
portion B where the second prepreg tape reinforcing element 14 is 
overlapped with the prepreg tape base 12. 
The width R of the first and second prepreg tape reinforcing elements 13, 
14 is set shorter than half of the width W. Also, in the pipe-like member 
forming tape 15, a portion C other than the first and second overlapping 
portions A, B is reserved. At this portion C, the tape base 12 is exposed 
without being overlapped by the first or second tape reinforcing element. 
Accordingly, in winding the tape 15 about the mandrel 3, this portion C 
can be readily deformed along the side edges of the previously wound turns 
of the reinforcing elements 13, 14. 
(d) Then, as illustrated in FIGS. 10 and 11, this pipe-like member forming 
tape 15 is wound about the mandrel 3 in a spiral pattern with the 
alignment direction of the reinforcing fiber of the prepreg tape base 12 
being slightly inclined relative to the axis of the mandrel 3. In the 
course of this winding operation, a subsequent overlapping portion B of 
the tape 15 is overlapped on a foregoing non-overlapped portion A of the 
tape 15. 
Further, during the winding operation, an appropriate measure such as 
application of a braking force to the rotary support shaft 4 for the tape 
is taken so as to cause the tape 15 to contact the mandrel 3 with an 
appropriate amount of contact pressure. 
(e) Thereafter, as illustrated in FIG. 12, on an upper surface of the wound 
tape 15, the heat-contracting type tape 5 is wound and then this assembly 
is sintered. 
According to the above-described method, it is possible to form recesses 
11a in the fishing rod 11 formed by the winding of the tape 15, so that 
the uneveness by these recesses 11a serves to prevent a wet fishing line 
from being stuck to the rod by effectively dissipating the water. 
Some other embodiments of the present invention will be described. 
(1) As shown in FIG. 13, it is conceivable to form the pipe-like member 
forming tape 15 by overlapping the prepreg tape reinforcing element 13 
only on one face of the prepreg tape base 12. For winding this pipe-like 
member forming tape 15 about the mandrel 3, the overlapping portion where 
the prepreg tape reinforcing element 13 is overlapped on the prepreg tape 
base 12 is wound to be laid on the non-overlapped portion consisting 
solely of the prepreg tape base 12. 
(2) The present invention may be applied to the manufacture of pipe like 
members other than those disclosed above, such as a pipe-like component of 
a small machine. Further, it is also conceivable to form a plurality of 
the prepreg wound layers of the invention. 
The invention may be embodied in other specific forms without departing 
from the spirit or essential characteristics thereof. The present 
embodiments are therefore to be considered in all respects as illustrative 
and not restrictive, the scope of the invention being indicated by the 
appended claims rather than by the foregoing description and all changes 
which come within the meaning and range of equivalency of the claims are 
therefore intended to be embraced therein.