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.

Abstract: A needle thread feed regulating device utilized in high speed overedge sewing machines which form safety stitches composed of overedge stitches and double chain stiches. The needle thread feed regulating device comprises a thread guide mounted on the sewing machine frame and an oscillating thread guide which moves in cooperation with the sewing machine main shaft. The oscillating thread guide has a cam plate which regulates the feed of both the thread for overedge stitches and the thread for double chain stitches.