Abstract: An improved guide device for the horizontal motion mechanism for the upper feed dog of an overlock sewing machine including an angularly adjustable bracket element that cooperates with a vertically adjustable slide to provide adjustability in the amount of shaft oscillation while attaining higher operating speeds.

Abstract: An apparatus for adjusting stitch length in a sewing machine by means of a selectively adjustable eccentric possessing a self-locking device. The apparatus includes a support collar fixed on the machine's main shaft with an eccentric support mounted on the support collar which is operatively connected to a connecting rod for actuating the machine's feed dog. The eccentric support includes a central opening within which the adjustable eccentric is operatively disposed and which forms an integral part of a support ring rotatably mounted on the machine's main shaft. A manually operable push button serves to hold the support ring stationary and to release the self-locking device. The machine includes the conventional hand wheel fixed on one end of the machine's main shaft and, while the pushbutton is held in a depressed condition, the self-locking device remains in a released state thus enabling the selective rotation of the machine's main shaft by the hand wheel.