Abstract: A travel control method for a self-propelled carriage having a travel control section for controlling steering-driving wheels. In the method, the steering-driving wheels are steered by a predetermined angle based on a direction change command, and in this state, the carriage is moved forward and backward for a predetermined distance to make the carriage depart from a base line. Then, the carriage is steered toward the base line to return to the base line. After that, the carriage is made to be able to travel along the base line.

Abstract: A screw fastening device having a compact clutch that is directly connected to an output side of a DC motor. The output of the DC motor can be suppressed so that the DC motor and the clutch can be made compact. Accordingly, the device main body is more compact and lighter.

Abstract: A travel control method for a self-propelled carriage having a travel control section for controlling steering-driving wheels. In the method, the steering-driving wheels are steered by a predetermined angle based on a direction change command, and in this state, the carriage is moved forward and backward for a predetermined distance to make the carriage depart from a base line. Then, the carriage is steered toward the base line to return to the base line. After that, the carriage is made to be able to travel along the base line.

Abstract: Assuming that t1 represents a period of time until a detection signal is outputted after a sensor senses a laser beam passed through a through-hole of a workpiece, t2 represents a period of time until the detection signal derived from the sensor exceeds a preset threshold value, and t3 represents a period of time until radiation of the laser beam is actually stopped after the threshold value is exceeded, a total period of time (t1+t2+t3) of the periods of time t1 to t3 is set to be shorter than a time difference (T2−T3) between a pulse width (T3) and one cycle (T2) of a pulse signal for constructing a laser output command signal.

Abstract: Assuming that t1 represents a period of time until a detection signal is outputted after a sensor senses a laser beam passed through a through-hole of a workpiece, t2 represents a period of time until the detection signal derived from the sensor exceeds a preset threshold value, and t3 represents a period of time until radiation of the laser beam is actually stopped after the threshold value is exceeded, a total period of time (t1+t2+t3) of the periods of time t1 to t3 is set to be shorter than a time difference (T2−T3) between a pulse width (T3) and one cycle (T2) of a pulse signal for constructing a laser output command signal.