Abstract: In an upper looper holder guide 7 through which an upper looper holder 12 penetrates, a first oil discharge hole 27 is opened in the edge at the upper end of a through-hole 11 and a second oil discharge hole 28 opened in the groove 26 and are branched off, the opening of the first oil discharge hole 27 contacts with the upper looper holder 12, and the opening of the second oil discharge hole 28 and groove 26 are exposed from a longitudinal hole 6 of an upper looper base 4 when the upper looper holder 12 reaches the top dead center or the bottom dead center. The oil discharge device is composed of a two-layer trochoid pump.

Abstract: A push-up lever is rotatably supported on a sewing machine frame, and a coupling lever is coupled to the push-up lever. An oscillating shaft is rotatably supported on a bush, and the coupling lever is engaged with a part of the oscillating shaft. A presser base is coupled to a crank piece of the oscillating shaft, and a presser foot is fixed at its leading end. An elastic member engaged with the presser base. A bracket changeable in fixing position is supported on the back side of the sewing machine frame, and the bush is fixed in the bracket. The crank piece of the oscillating shaft is separable in two pieces, and the engaging faces of the two separated crank pieces are fixed anew when changing the fixing position of the bracket. Therefore, the circular track of the presser foot near the platform of the sewing machine bed can be changed easily, and an eccentric portion of the crank piece is not changed from an initial setting position.

Abstract: A push-up lever is rotatably supported on a sewing machine frame, and a coupling lever is coupled to the push-up lever. An oscillating shaft is rotatably supported on a bush, and the coupling lever is engaged with a part of the oscillating shaft. A presser base is coupled to a crank piece of the oscillating shaft, and a presser foot is fixed at its leading end. An elastic member engaged with the presser base. A bracket changeable in fixing position is supported on the back side of the sewing machine frame, and the bush is fixed in the bracket. The crank piece of the oscillating shaft is separable in two pieces, and the engaging faces of the two separated crank pieces are fixed anew when changing the fixing position of the bracket. Therefore, the circular track of the presser foot near the platform of the sewing machine bed can be changed easily, and an eccentric portion of the crank piece is not changed from an initial setting position.

Abstract: In an upper looper holder guide 7 through which an upper looper holder 12 penetrates, a pass hole 25 opened in a spot facing 24, and a groove 26 parallel to the pass hole 25 on the outer circumference of the upper looper holder guide 7 are formed. From the pass hole 25, a first oil discharge hole 27 opened in the edge at the upper end of a through-hole 11 and a second oil discharge hole 28 opened in the groove 26 are branched off, the opening of the first oil discharge hole 27 contacts with the upper looper holder 12, and the opening of the second oil discharge hole 28 and groove 26 are exposed from a longitudinal hole 6 of an upper looper base 4 when the upper looper holder 12 reaches the top dead center or the bottom dead center.

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.

Abstract: An upper feed mechanism of a sewing machine, in which a horizontal motion mechanism for moving the upper feed dog back and forth is provided with a double lever mechanism composed of a single arm lever, a bifurcate lever and a slider slidably mounted on both levers, and a crank lever mechanism for oscillating the levers. When a crank of the crank lever mechanism is at a top dead point or a bottom dead point, the radial directions of the levers are matched, and when the slider is moved in this state, the upper feed dog varies in the feed amount while the front position or rear position is constant.

Abstract: A needle driving apparatus for a sewing machine for allowing oscillatory movement of a needle bar through the motion of a lever which oscillates up and down interlocking with a main shaft, wherein a rectangular slider is rotatably supported by a fork provided on the end of the oscillating lever. On the upper end of the needle bar is fixed a guide member having a guide groove which is orthogonal with the needle bar and slidably fitted to the fork of the oscillating lever, and the rectangular slider is fitted in the guide groove of the guide member.

Abstract: A lifting rocker which is pivotally supported by a link is engaged with an eccentric ring which is fixed to a main shaft of a sewing machine. By the rotation of the eccentric ring, the lifting rocker rocks up and down about a fulcrum defined by the link while causing the link to rock. A feed bar having thereon a feed dog is slidably supported by the lifting rocker, and moves in back and forth directions through the rocking of the arm to constantly maintain a definite amount of feed without respect to variation of the rotational speed of the main shaft of the sewing machine.

Abstract: A top feed device for a sewing machine has an upper feed dog movable horizontally and vertically in synchronism with operation of a lower feed dog. The upper feed dog is vertically moved by a spring for depressing an upper feed arm to which the upper feed dog is attached, and a crank engages the upper feed arm and is vertically swingable, the crank being held in engagement with the upper feed arm at all times to prevent striking engagement therewith. A swingable shaft to which the crank is fixed and a lever angularly movably mounted on the swingable shaft and swingable in coaction with a drive shaft have abutments projecting axially in confronting relation. The abutments on the shaft are urged by a spring to angularly move in one direction. The abutments on the lever which are held against the other abutments are disengaged therefrom in a circumferential direction when the upper feed dog reaches a throat plate and stops its downward movement.