1. Field of the Invention
The present invention generally relates to a gear mounting structure. More specifically, the present invention relates to a gear mounting structure for mounting a shaft to a gear in a reciprocating movement mechanism of a fishing reel.
2. Background Information
Fishing reels mainly include spinning reels and dual bearing reels. This type of fishing reel has a reel main body mounted on a fishing rod and a spool provided in the reel main body to wind fishing line. In dual bearing reels, the spool is supported on the reel main body so as to be freely rotatable. The spool is provided with a level winding mechanism for evenly winding the fishing line onto the spool. In spinning reels, an oscillating mechanism is provided on the reel main body so as to move freely front-to-back in order to evenly wind the fishing line onto the spool.
The level winding mechanism in the dual bearing reel is provided with a screw shaft disposed parallel with a spool shaft installed in the spool, a linkage mechanism for rotating the screw shaft, and a fishing line guide that connects with a spiral groove formed in the screw shaft so as to reciprocatingly guide the fishing line (for example, refer to Japanese Laid-Open Patent Publication No. 2000-23600). The oscillating mechanism of the spinning reel is provided with a linkage mechanism for rotation of a handle, a screw shaft that rotates by a linkage mechanism disposed parallel with a spool shaft, and a slider connected to the screw shaft and capable of reciprocating movement with the spool shaft in a screw shaft direction. A fishing line is evenly wound on the spool by the rotation of the screw shaft via the rotation of the handle, and the reciprocating movement of the slider and the fishing line guide. The linkage mechanism has gear components provided to transfer the rotation of the handle. The gears are installed on a leading end at one end of the screw shaft so as to be relatively non-rotational. Specifically, the cross section of the end of the screw shaft in the axial direction is formed in a non-circular shape. A non-circular through hole is formed so as to pass through a center of the gear. The end of the screw shaft engages the through hole of the gear component such that the screw shaft and the gear component are relatively non-rotational.
Since the gear components are installed on one end of the screw shaft so as to be relatively non-rotatable in conventional level winding mechanisms, the screw shaft can be rotated in linkage with the rotation of the handle. However, since only the end of the screw shaft engages the through hole of the gear, some instability is generated between the end of the screw shaft and the through hole of the gear. When the gears are rotated in conjunction with the rotation of the handle, and particularly when the rotational torque of the screw shaft changes as the fishing line guide part and slider reverse direction at the end positions of the screw shaft, there is an increased instability between the end of the screw shaft and the through hole of the gear so as to cause a concern about a decrease in sensitivity in the handle operation by the fisherman.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved gear mounting structure that to suppress the decrease in sensitivity in the handle operation by the fisherman in a gear mounting structure. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.