PURPOSE: To provide possibility of inserting a spigot a certain proper amount into a socket without checking by eyes even in case pipe joining is made automatically in an open cut groove.
CONSTITUTION: A position near the spigot 46 of one 44 of the pipes to be joined together and a position near the socket 48 of the other pipe 42 are clamped by stationary clamp devices 20, 22 and a moving clamp device 30. The clamp devices 20, 22 and the one 30 are approached to one another, and the two pipes 44, 42 are joined together. A pipe end sensor 54 and a mark sensor 56 located at a certain distance from each other are located abut the pipe axis direction by a moving member 52, and the sensor 54 senses the pipe end of the socket 48. If in this condition, the mark sensor 56 senses a mark 58 provided on the outer surface of the spigot 46, it is sensed that the spigot 46 is inserted by the specified amount into the socket 48.
TOSHIMA TOSHIO
ISHIZAKI YOSHIKI
