Importance

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Abstract

An upper feed device for a sewing machine comprises an upper feed arm having its base end coupled with a longitudinally swinging crank and an upper feed dog attached at its front end. The mechanism for vertically moving the upper feed arm consists of a clutch mechanism comprising a lever rotatably mounted on a vertical feed shaft and swinging in cooperation with the main shaft, an abutment disposed on the lever and an abutment of a collar disposed on the vertical feed shaft, which is capable of disconnecting the cooperation of the lever and the vertical feed shaft, and a crank having a roller slidably fitting with a guide disposed parallel to the upper feed arm and which moves vertically through its attachment to the vertical feed shaft. A block is provided below the roller to engage with the free lower end surface of the crank and is adjustable in its mounting position to prevent the roller from descending more than specified. The upper surface of the block engages with the free lower end surface of the crank and is inclined.

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First Claim