| 摘要 |
PROBLEM TO BE SOLVED: To reduce costs required for components and to improve wear resistance and seizure resistance even under the condition that the supply of lubricating oil is limited. SOLUTION: In the needle bar driving mechanism 1 of a sewing machine comprising a needle bar drive shaft 11 to be swung by the transmission of the drive of a sewing machine motor, a needle bar drive arm 12 provided on the needle bar drive shaft 11 to be swung accompanying the swing operation of the needle bar drive shaft 11, a needle bar drive link 18 freely turnably connected via a first pin 14 to the needle bar drive arm 12 and a needle bar 20 freely turnably connected through a second pin 19 to the needle bar drive link 18 for holding a sewing needle 30 at the lower end, in which the needle bar 20 is driven in a vertical direction by the drive of the sewing machine motor, the first pin 14 and the second pin 19 are composed by forming chromium nitride layers 14c and 19c on the surface under the environment below the tempering temperature of base materials 14a and 19a. COPYRIGHT: (C)2007,JPO&INPIT
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