Abstract: A transverse axis tubular hub (24) couples each propulsion unit (4) to the vehicle body (2), and supplies signals representative of the forces that it transmits. A tilt motor (22) of the propulsion unit bears on the hub to tilt the propulsion units about a transverse axis, on which a drive motor is disposed.

Abstract: A transverse axis tubular hub (24) couples each elongate propulsion unit (4) to the vehicle body (2). It supplies signals representative of the forces that it transmits. A tilt motor (22) of said propulsion unit bears on said hub to tilt said propulsion units about said transverse axis. In accordance with the invention a drive motor is disposed on said axis.The invention is particularly applicable to working in environments harmful to man.

Abstract: The device comprises an elongate transmission member (30) which can be moved inside the steam generator tube by pulling and pushing. The elongate member (30) comprises a central metal cable (31), a flexible peripheral sheath (32) and a plurality of annular members (33) which are not connected together and are threaded in sequence onto the flexible sheath (32). A clearance (34) corresponding to the difference in length between the sheath (32) and the total length of the members (33) when they are placed end to end allows the member (30) to be moved inside the tube by pushing without the application of great force. In particular, the device enables heating elements to be inserted and positioned in the curved parts of the tbes of the bundle of a steam generator of a pressurized-water nuclear reactor.