Abstract: A sewing machine includes a needle bar, a needle bar up-and-down movement mechanism, a swinging mechanism, a lower shaft, an outer shuttle, a thread cutting mechanism, a rotation speed adjustment mechanism, and an actuator. The needle bar up-and-down movement mechanism is configured to move the needle bar up and down. The swinging mechanism is configured to swing the needle bar in a left-right direction. The lower shaft is configured to rotate in synchronization with up-down movement of the needle bar. The outer shuttle is configured to rotate along with rotation of the lower shaft. The thread cutting mechanism is configured to cut at least an upper thread. The rotation speed adjustment mechanism is configured to adjust a rotation speed of the outer shuttle. The actuator is a driving source of the thread cutting mechanism and the rotation speed adjustment mechanism.

Abstract: The present invention provides a sewing machine that can perform zigzag sewing a cylindrical sewn article. A sewing machine 1 includes an approximately cylindrical guide member 11 that guides a sewn article A, a sewing needle 99 that sews the cylindrical sewn article A, a holding member 71 that holds the sewing needle 99 approximately vertically, a vertical hook 21 provided in the guide member 11 so that the direction of rotation is approximately perpendicular to the axial direction C of the guide member 11 and that catches the upper thread loop of the sewing needle 99, a rotary shaft 22 that rotates the vertical hook 21, and an operating means 50 that moves the holding member 71 and the rotary shaft 22 reciprocatingly at approximately the same time.

Abstract: A looptaker driving arrangement in a zig-zag sewing machine includes: a rotatable drive shaft driving rotation of the looptaker of the sewing machine; a main drive member rotatably supported on the drive shaft; a secondary drive member fixed on the drive shaft for concurrent rotation therewith; a bushing rotatably mounted on the drive shaft with an eccentric outer periphery; and a coupling member rotatably mounted on the periphery of the bushing in eccentric relation to the drive shaft and engaging the main drive member and the secondary drive member. Rotation of the main drive member about the drive shaft axis combined with rotation of the bushing about the drive shaft axis relative to the main drive member angularly accelerates and decelerates the secondary drive member with respect to the main drive member and, in turn, angularly accelerates and decelerates the drive shaft.

Abstract: A zigzag sewing machine includes a needle hole member having a round needle hole of a diameter slightly larger than that of a stitching needle. The needle hole member engages a laterally elongated hole in a needle plate and is swingable along the latter. A base member is mounted coaxially with a loop taker and is rotatable relative to the loop taker. The needle hole member is pivoted to the base member for relative vertically swinging movement. A lever swingably mounted on the machine housing engages with the needle hole member, and a cam rotated in synchronism with the vertical reciprocation of the needle is in engagement with the swinging lever. A stepping motor is operatively connected to the needle to reciprocate the needle laterally in the elongated needle plate hole, and the motor is also operatively connected to the base member to reciprocate the base member.

Abstract: A device for changing a lower thread running path in a zigzag sewing machine includes a guiding member positioned between a lower thread holder and a needle plate and having an obliquely positioned guiding face the obliquity of which to the direction of the needle amplitude is controlled to selectively produce straight stitches or zigzag stitches.

Abstract: A lower thread drawing-out device for a computerized sewing machine, the device having a cup-shaped loop taker with a surrounding wall. The loop taker is rotatable in a timed relation with a vertical reciprocation of the needle to catch the upper thread to concatenate with the lower thread and thereby form lock stitches. A bobbin is arranged in the loop taker so as to form a space between the bobbin and the loop taker surrounding wall. A lower thread drawing out element having a free end in the space is arranged so that when a lower thread is wrapped around the bobbin and extends to a needle, the free end contacts the lower thread at a location. The lower thread drawing out element is rotatable relative to the loop taker. The lower thread is movable transversely at the contact location relative to the lower thread when extended and in response to a rotation of the element relative to the loop taker, thereby compensating for biasing of the lower thread.

Abstract: A thread loop taker device for a zigzag sewing machine having a needle whose position is controlled by electronically stored data which cooperates with the thread loop taker device to thereby produce zigzag stitches. The thread loop taker device comprises a bobbin carrier, a rotational cylindrical member for supporting the bobbin carrier therein; a loop taker coaxial with and about the cylindrical member for rotation therewith, the loop taker having a beak extending from one end and in the direction of the rotation around a portion of the cylindrical member for catching a thread loop formed by the needle; cams rotating with the cylindrical member and engaging the opposite end of the loop taker for rotating the beak relative to the cylindrical member; and a pulse motor drivable in response to a change in the position of the needle so that, when this driving is transmitted to move the cams, the loop taker is actuated.

Abstract: A thread loop taker device for a zigzag sewing machine having a needle whose position is controlled by electronically stored data which cooperates with the thread loop taker device to thereby produce zigzag stitches. The thread loop taker device comprises a bobbin carrier, a rotational cylindrical member for supporting the bobbin carrier therein; a loop taker coaxial with and about the cylindrical member for rotation therewith, the loop taker having a beak extending from one end and in the direction of the rotation around a portion of the cylindrical member for catching a thread loop formed by the needle; cams rotating with the cylindrical member and engaging the opposite end of the loop taker for rotating the beak relative to the cylindrical member; and a pulse motor movable in two opposite directions in response to a change in the position of the needle so that, when this movement is transmitted to the cams, the loop taker is actuated.

Abstract: A needle guard for an industrial zigzag sewing machine designed to provide support for the sewing needle in all lateral positions of the needle. The needle guard provides a lead in surface to return an already deflected needle to a supporting surface which in a first embodiment lies in a plane immediately adjacent a plane including the circular path traversed by the loop seizing beak. In a second embodiment a supporting surface is provided which compensates for the point of contact variations due to the cone pointed end of the sewing needle.