| 摘要 |
PROBLEM TO BE SOLVED: To provide a novel gear crank for a bicycle reduced in loss of material plates and capable of maintaining the predetermined rigidity or more of each gear in the condition that a plurality of gears are unified. SOLUTION: In this gear crank 1 for a bicycle, a plurality of gears are unified in parallel with each other so that diameter thereof is reduced in order from an outer side, and this gear set 2 is fixed to a boss part 41 of a crank arm 40 for fixation. Among the plurality of gears, a selected first gear is provided with an inward projection 14 to be fitted between gear teeth 33 of a second gear when the center of the first gear is overlapped with the center of the second gear selected on the small-diameter side of the first gear. This inward projection 14 forms a part of the first gear positioned in the most inside in the radial direction, and the first gear is connected to an adjacent gear on the small-diameter side near the inward projection 14. COPYRIGHT: (C)2004,JPO
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