Vehicle for inspecting and maintaining steam generator tubes or the like

A vehicle for selectively positioning a tool relative to tubes in a bundle of tubes received in a tube plate and opening out into an enclosure including an access opening, the vehicle comprising at least two transfer arms including means for causing expansible positioning fingers to penetrate into said tubes and for extracting said fingers from said tubes perpendicularly to said tube plate in order to displace the vehicle adjacent the face of the tube plate situated in said enclosure, with at least one of said arms including a tool support having means for presenting a tool successively on the axis of a plurality of tubes in the plate, which vehicle includes at least two pivoting fastening heads, an extremity head and an intermediate head, each of said heads comprising a body with a cylindrical bore in which a hollow telescopic shaft is coaxially mounted, said shaft comprising two elements, one of which is moveable in translation by drive means, and the other of which is mounted to rotate in said body, said expansible positioning fingers being mounted in said moving element by means capable of extending said expansible positioning fingers beyond the end of said shaft or of retracting said fingers into said shaft, said fingers being parallel to each other and to said pivoting heads, said heads being fixed to said transfer arms, a first telescopic arm extending perpendicularly to said pivoting fastening heads which are interconnected to each other by the said first arm, and a second telescopic arm fixed to said intermediate head and extending perpendicularly to said intermediate head and supporting said tool support.