Fishing – trapping – and vermin destroying – Fishing – Rod
Reexamination Certificate
1995-12-06
2001-10-16
Rowan, Kurt (Department: 3643)
Fishing, trapping, and vermin destroying
Fishing
Rod
C043S018500
Reexamination Certificate
active
06301821
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a tubular substance made by winding prepreg provided by impregnating reinforcing fibers aligned or oriented mainly in one direction with thermosetting resin and pressurizing and heating it, and a manufacturing method therefor. Therefore, it can be used for rod pipes of fishing rods, shafts of golf clubs, etc.
Fishing rods need to be lightweight because they are held for long hours and from the viewpoint of improvement in operability and further need to be improved in strength because they receive a large bend force of strong pulling of fish, etc. Golf clubs also need to have light and highly strong nature. Thus, fishing rods and shafts of golf clubs need to satisfy compatibility of antithetic properties of lightweight and high strength. Therefore, hitherto, lightweight and strong tubular substances have been made by impregnating highly strong and lightweight fibers such as carbon fibers with synthetic resin such as epoxy resin for forming prepreg and winding, pressurizing, and heating the prepreg.
In this case, the fact that the weight percentage of resin in the prepreg generally is 35% to 40% is disclosed in Japanese Patent Publication No.Hei 2-44492. The Publication specifies the relationship between the resin impregnation amount of the first prepreg of the innermost layer of a rod pipe and that of the second prepreg for the main layer of an outer layer from the viewpoints of conformability with the mandrel and coherency of the layers, wherein the fact that the resin impregnation amount of the prepreg of the innermost layer is 50% or less and that of the outer layer is 30% or less is disclosed.
However, the weight increases because the resin amount is large as a whole. Further, because the above-disclosed resin amount is too much with respect to fibers, the formation of a resin layer or resin pool (portion with no or few fibers) where delamination or crack easily occurs is observed from photomicrographs. A resin flow occurs during molding, and thus fibers also move easily in association with the resin flow to meander or lean to one side, whereby lowering of strength or unintentional bending easily occurs.
Particularly, if the resin amount of the prepreg for the main layer exceeds about 25 wt %, when the prepreg is wound and thereafter tightened with tape and heat-molded, circumferential shift of the prepreg material occurs during the molding depending on the tightening condition and molding failure often occurs. However, if prepreg impregnated evenly with a small amount of resin is used, coherency on boundaries of wound layers worsens and voids occur on the boundaries. Particularly on the prepreg-wound layer boundaries of fibers oriented in the length direction of the mandrel, the voids easily occur continuously in the length direction, causing the strength to lower due to delamination.
Japanese Utility Model Laid-Open Publication No.Hei 6-7923 discloses the fact that heating and molding in a state in which a resin flow from an inner layer to surface layer is suppressed is a point to be considered. On the other hand, this publication also discloses the fact that an inner reinforcement layer contains a larger resin impregnation amount than the main layer for conformity with a mandrel and that an outer reinforcement layer contains a larger resin impregnation amount than the main layer for discharging air pools.
However, if the resin percentages of the reinforcement layers are set larger than that of the main layer for conformity with the mandrel and for pushing out air pools of the outer reinforcement layer, the resin flow from the inner layer to the outer layer is not completely suppressed. Therefore, it is desired that the layers have the same resin percentage.
The conformity with the mandrel may be achieved, for example, by adjusting the molding temperature and pressurization force instead of setting the large amount of resin. Air pools can be pushed out by another method instead of setting the large amount of resin for preventing air pools from being produced at prepreg molding. However, the lightweight of the molded rod pipe and improvement in the specific rigidity can be accomplished only by adjusting the resin amount.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a tubular substance which is highly strong and has excellent durability without impairing the lightweight and a manufacturing method therefor.
According to one aspect of the invention, under concepts of achieving the lightweight and preventing resin from flowing, there is provided a fishing rod comprising a main layer formed by winding a first prepreg provided by impregnating highly strong fibers with resin so that weight percentage becomes 25% or less so that the fibers are oriented in an axial length direction and a reinforcement layer formed by winding a second prepreg provided by impregnating highly strong fibers with resin so that the fibers are oriented in a direction crossing the fiber orientation of the main layer on at least one side of the inside and outside of the main layer, wherein the reinforcement layer is formed thinner than the main layer, and that resin impregnation percentage of the second prepreg is set to substantially the same as that of the first prepreg.
The resin impregnation percentage of each prepreg of which the main layer and the reinforcement layer are formed is set to substantially the same value and the resin percentage is made small to 25% or less, preventing resin from flowing, thereby preventing leaning of fibers, resin pools, and resin pool layers, the strength being improved. Since the entire resin percentage is small, the lightweight of the fishing rod is achieved and specific rigidity is improved. The reinforcement layer, which does not contribute to flexible rigidity of the fishing rod unlike the main layer with fibers oriented in the axial length direction, is formed thinner than the main layer for furthermore achieving the lightweight.
Substantially the same resin impregnation percentage refers to increase or decrease within the range of about 5%, preferably within the range of about 3%.
According to another aspect of the invention, there is provided a method of manufacturing a tubular substance comprising the steps of preparing a prepreg by impregnating carbon fibers with thermosetting synthetic resin so as to have a poor resin amount area and a rich resin amount area in a thickness direction and to contain an average impregnation amount of the thermosetting synthetic resin approximately in the range of 10 wt % to 20 wt %, winding the prepreg with the carbon fibers mainly oriented substantially in a length direction of a mandrel in plural turns so that a rich resin amount area is located in at least one of adjacent layers at a wound boundary, to thereby form a relatively thick layer corresponding to a main layer, winding a prepreg provided by impregnating reinforced fibers with thermosetting synthetic resin prior to, simultaneously with and/or subsequently to the above winding step so that its main fiber orientation crosses the carbon fibers oriented substantially in the length direction for forming at least one relatively thin layer corresponding to a reinforcement layer, pressurizing the layers corresponding to the reinforcement layer and main layer by a tightening substance from. the outside and heating them, and removing the mandrel and the tightening substance.
The “wt %” refers to weight percentage to the total weight of the fibers and resin. The layer corresponding to the reinforcement layer may be placed within the layer corresponding to the main layer as well as on the inside or outside of the layer corresponding to the main layer. That is, for example, a manufacturing method of a tubular substance having the main layer with alternate disposition of a fiber layer in the substantial length direction and a thin layer (backing layer) having fibers in the substantially circumferential direction is also contained.
Although the prepreg contains a poor resin amount area and a rich
Kameda Kenichi
Naitou Hideyuki
Suzue Hiroyasu
Takamatsu Nobuaki
Tsurufuji Tomoyoshi
Daiwa Seiko Inc.
Liniak Berenato Longacre & White
Rowan Kurt
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