Abstract: A feed dog device of a sewing machine includes a driving unit, a needle plate unit, a feed dog unit, an up-down transmitting unit, a horizontal transmitting unit and a direction adjusting unit. The direction adjusting unit includes a stepper motor with a variable rotational speed controlled in accordance with a speed of the driving shaft of the driving unit, and a linkage mechanism actuatable by the stepper motor to be moved to different positions so as to interfere with a horizontal reciprocating motion by the horizontal transmitting unit such that the horizontal reciprocating motion cooperates with the up-down reciprocating motion by the up-down transmitting unit to bring the feed dog unit into performing a variable moving course.

Abstract: A thread feeding device of a sewing machine includes a needle bar movable vertically to pull an upper thread through a fabric, and movable between left and right terminal positions. An imaginary plane to which the needle bar is normal is defined, and includes left and right boundary lines which pass through the left and right terminal positions. An inner rotary hook includes a thread tensing unit disposed on a hook surrounding wall. A lower thread passes through and abuts against the thread tensing unit to define at least one thread abutting point. A final abutting point where the lower thread passes through the thread tensing unit immediately before reaching the fabric is defined, and is projected on the imaginary plane at a point that is interposed between the boundary lines.

Abstract: A clutch device used to couple/decouple a reciprocating force of a drive member to/from a needle bar in a sewing machine includes an actuating lever actuated by an electromechanical unit to be pivotable between an idle position to disengage from an actuated end of a clutch lever so as to leave a grasp end of the clutch lever in a coupled state, where the grasp end is engaged with a coupled portion disposed on a drive member, thereby transmit the reciprocating force to the needle bar, and an actuating position to be in pressing engagement with the actuated end so as to displace the grasp end to a decoupled state, where the grasp end is disengaged from the coupled portion.

Abstract: A clutch device used to couple/decouple a reciprocating force of a drive member to/from a needle bar in a sewing machine includes an actuating lever actuated by an electromechanical unit to be pivotable between an idle position to disengage from an actuated end of a clutch lever so as to leave a grasp end of the clutch lever in a coupled state, where the grasp end is engaged with a coupled portion disposed on a drive member, thereby transmit the reciprocating force to the needle bar, and an actuating position to be in pressing engagement with the actuated end so as to displace the grasp end to a decoupled state, where the grasp end is disengaged from the coupled portion.

Abstract: A controller for an electric article includes a voltage-stabilizing circuit for supplying voltage stable DC power, a microprocessor, a temperature-detecting circuit, a protecting circuit, a control circuit, and a switch circuit. The temperature-detecting circuit includes several comparators commonly connected to a temperature range switch. The protecting circuit includes a comparator that detects a pre-set highest heating temperature and that is connected to the voltage stable DC power and a voltage-detecting circuit of the voltage stable DC power. The comparator of the protecting circuit is further connected to a voltage-dividing end of a thermistor connected to a temperature-detecting wire. The control circuit is connected to the microprocessor and an output of the comparator of the protecting circuit. The switch circuit is connected to an output of the voltage stable DC power and the control circuit, thereby controlling conduction or cutting off DC power supply to the electric article.