Abstract: A first arm (3) of a articulated robot has a double arm structure composed of a first arm piece (3a) and a second arm piece (3b). The first arm piece (3a) transmits a drive force, and a housing (4a) of a second arm (4) is rotatably mounted to the first arm piece (3a) at the end thereof. The second arm piece (3b) houses cables and pipes or the like, and a cover (4b) of the housing (4a) is rotatably mounted to the second arm piece at the end thereof. The cover (4b) is fixed to the housing (4a) through a fixing tool (6). The housing (4a) is permitted to be opened by separating the housing (4a) and the cover (4b) from each other by causing the second arm piece (3b) to rotate relatively to the first arm piece (3a) after the removal of the fixing tool (6).

Abstract: A weld-position detector, attached to an automatic welding machine such as a welding robot, having three independently produced indispensable units, i.e., a laser-beam projecting unit for projecting a detection laser-beam, a scanning unit for directing the detection laser-beam towards weld portions of a workpiece and scanning the detection laser-beam across the welded portions, and a light-receiving unit for detecting the detection laser-beam reflected by the workpiece to thereby detect the position of the weld portions. The weld-position detector further having a fixture provided with reference faces on which the three independent units are accurately mounted.

Abstract: A window mechanism for a sensor provided at the distal end of a robot arm of an industrial robot comprises a housing for enclosing the sensor which housing includes an opening, a glass plate for closing the opening, wiper for wiping the outer surface of the glass plate, a holder plate for slidably holding the glass plate member on the housing, and an exchanger for exchanging the plate member held by the holder with a new glass plate.

Abstract: A cooling and cleaning unit incorporated in a welding position detector having a gas introducing conduit for introducing a single flow of a cooling gas under pressure into a hermetically sealed chamber of a casing for encasing therein a sensor unit of the welding position detector in the form of a convectional flow of cooling gas circulating around the sensor unit and removing heat from the sensor unit, a check valve unit having a gas inlet and a gas outlet and permitting the cooling gas under pressure to be discharged from the hermetically sealed chamber toward an outer face of a protective window of the welding position detector in the form of cleaning gas under pressure to thereby clean the outer face of the protective window while forming a gas curtain extending over the outer face of the protective window so as to prevent welding fumes and sputter from attaching to and depositing onto the outer face of the protective window of the welding position detector.