Abstract: The welding position detecting apparatus incorporates a detecting portion including light emitter for emitting a light stripe onto a beveling surface of a work to be welded and a camera for receiving a reflected light from the beveling surface, a support member to which the detecting portion is mounted, which is disposed for rotation about an axis of the welding torch, and a motor for rotating the support member, whereby the detecting portion is rotated to a desired angular position about the axis of the welding torch.

Abstract: In a grip device wherein bimorph type piezoelectric elements are employed for fingers or claws for grasping a workpiece, a grip device comprising bimorph type piezoelectric elements which are mounted on a grip body and which form finger or claws, a voltage feed circuit which is connected to the piezoelectric elements in order to bend and deform the piezoelectric elements, and a control circuit is connected to an end of the piezoelectric elements providing an output signal for controlling a grasping force for a workpiece.

Abstract: An automatic welding line tracing method and apparatus for causing a welding torch to follow the welding line by using a single non-contact-type sensor for detecting the welding line which is continuously reciprocated to traverse the groove of two pieces to be welded. During the reciprocating motion of the sensor, the sensor generates output voltages E.sub.1 and E.sub.2 respectively obtained by detecting the both ends of the groove to obtain E.sub.1 -.delta. and E.sub.2 -.delta. on the basis of the detected voltages E.sub.1, E.sub.2 and a separately established reference voltage .delta., and an output voltage P.sub.S corresponding to the central position of the groove is obtained from E.sub.1 -.delta. and E.sub.2 -.delta. to thereby compare the voltage P.sub.S with a voltage indicative of the central position of the oscillating motion of the sensor to thereby cause the welding torch to follow the welding line in accordance with the difference between these two voltages.

Abstract: An automatic weld line copying apparatus has a non-contact type sensor including a core wound with an exciting primary winding which in turn is wound with a secondary winding a plurality of secondary coils differentially. The sensor is compact and able to detect, without contact, the distance from the flat surface or edge line of an object to be welded thus making possible accurate and efficient automatic welding of a small welding assembly with a complicated weld line.

Abstract: A method and apparatus for automatic weld line tracing using a non-contact sensor for detection of a weld line, which sensor is continuously reciprocated across the groove. Signals produced from the sensor during the reciprocation are compared at the ends of the groove, and the lower voltage value of the two signals is determined. A value lower than the lower voltage of the two signals by .delta. is predetermined and the position associated with the value is detected by a displacement-measuring instrument, the output of which is utilized for control of the positions of a welding torch.