Abstract: To provide a sewing machine that can control tension on a needle thread and tension on a bobbin thread on a per-stitch basis; that enables even heads of a multi-head embroidery sewing machine to form an identical embroidery; and that enables even a plurality of sewing machines to form identical embroidery. A memory device stores for each stitch of embroidery data a needle thread control torque value and a bobbin thread control torque value. In a needle thread torque control zone, an upstream grip section main body is closed, and a downstream grip section main body is opened. A needle thread motor is subjected to torque control in accordance with the needle thread control torque value. In the meantime, in a position control zone, the upstream grip section body is opened, and the downstream grip section body is closed, thereby subjecting the needle thread motor to position control.

Abstract: Each of front-back direction actuation blocks for actuating a sewing frame in a front-back direction has ball screws, motors, and movable members. An engagement roller of each of the movable members engages with a long side of the sewing frame, and an engagement roller of each of the movable members engages with a long side. The movable members of respective front-back direction actuation blocks are connected to short sides of the sewing frame. In each of the front-back direction actuation blocks, the ball screw and the ball screw are joined together by means of a joint member. Movable members of respective right-left direction actuation blocks support the respective front-back direction actuation blocks.

Abstract: To provide a sewing machine that can control tension on a needle thread and tension on a bobbin thread on a per-stitch basis; that enables even heads of a multi-head embroidery sewing machine to form an identical embroidery; and that enables even a plurality of sewing machines to form identical embroidery. A memory device stores for each stitch of embroidery data a needle thread control torque value and a bobbin thread control torque value. In a needle thread torque control zone, an upstream grip section main body is closed, and a downstream grip section main body is opened. A needle thread motor is subjected to torque control in accordance with the needle thread control torque value. In the meantime, in a position control zone, the upstream grip section body is opened, and the downstream grip section body is closed, thereby subjecting the needle thread motor to position control.

Abstract: [Problem] To provide a sewing frame actuator for a sewing machine capable of positioning a sewing frame with high accuracy by preventing occurrence of distortion of the sewing frame. [Means for Resolution] Each of front-back direction actuation blocks 70 for actuating a sewing frame 50 in a front-back direction has ball screws 86 and 106, motors 84 and 104, and movable members 87 and 107. An engagement roller 92 of each of the movable members 87 engages with a long side 52 of the sewing frame, and an engagement roller 112 of each of the movable members 107 engages with a long side 54. The movable members 87 and 107 of respective front-back direction actuation blocks 71 are connected to short sides 56 and 58 of the sewing frame 50. In each of the front-back direction actuation blocks 70 and 71, the ball screw 86 and the ball screw 106 are joined together by means of a joint member 124.