Juki Corporation

Yasuaki Hirano

Mitsuhiro Tachikawa

Kazuaki Ishii

Tsuguo Kubota

Takashi Tsukioka

Toshiaki Kasuga

A cloth cutting knife 16 is structured such that the length of the cutting edge thereof is set shorter than the length of the side sewing portions of a buttonhole to be formed, and a buttonhole having a length corresponding to the length of the right and left side sewing portions can be formed by moving up and down the cloth cutting knife 16 two or more times. The cloth cutting knife 16 is moved up and down at least once during formation of the stitches of the right and left side sewing portions. Also, the cloth cutting knife 16 is moved up and down once each time a given number of stitches of the right and left side sewing portions are formed. The given number of stitches is set in accordance with both of the length of the cutting edge of the cloth cutting knife 16 and the length of the buttonhole to be formed.

Buttonhole darning sewing machine

A buttonhole sewing machine includes a holding mechanism attached to a holder arm which reciprocates in a direction perpendicular to an amplitude direction of a needle. The holding mechanism includes a workpiece holder plate and constitutes a parallelogram linkage. The holding mechanism maintains a parallelogram shape even when the holder plate slants on a fold of the workpiece, and securely holds the workpiece. This buttonhole sewing machine also includes a cutting mechanism which cuts thread and braid in a short manner even when the holder plate slants. The cutting mechanism has a rotary cutter and a fixed cutter, and the fixed cutter is fixed on the holder plate while inclined from a proximal portion to a distal portion. A wire member is connected to the mobile cutter to facilitate the rotation of the rotary cutter even when the holder plate slants.

Growing community of inventors

Tokyo, Japan

Yasuaki Hirano