An apparatus for introducing and/or positioning a device in a chamber of a heat exchanger includes an assembly yoke with ends and a middle. The yoke may manually be introduced into the chamber of the heat exchanger with a pole. At least three remotely-actuatable clamping fingers are disposed on the assembly yoke. The clamping fingers are designed such that they may be locked or braced in tubes of the heat exchanger. For this purpose, respective locking devices that are remotely controllable may be used. A lifting cylinder holds one of the clamping fingers at least approximately at the middle of the yoke. Remotely-actuatable clamping devices each hold at least one of the clamping fingers on a respective one of the ends of the yoke. Toothed belts each have an end connected to a respective one of the clamping fingers positioned on the ends of the yoke. Two synchronously controllable elevators each have a toothed belt drive in engagement with a respective one of the toothed belts. Support elements and releasable connectors for the device to be introduced and/or positioned are disposed on the synchronously controllable elevators.

The present invention relates to a device for introducing a mobile positioning body onto a tube plate of a steam generator through a manhole. The device comprises two substantially parallel rails essentially shaped like a curved angle plate, whereby a trolley can slide along the rails and on which can be placed the said moving body. During the introduction of the moving body, the device is provisionally fixed to the tube plate by lugs and to the inner face of the manhole by a pedal maintained in place by a spring. Application to the inspection of steam generator tubes.

An elongated track assembly is provided for disposition outwardly of and paralleling one pair of corresponding ends of a row of tubes and the track assembly includes a support mounted therefrom for movement along the track assembly. An elongated and longitudinally projectable and retractable pilot member is mounted from the support as well as elongated and longitudinally projectable and retractable tool which parallels the pilot member. Power structure is provided operative to power project and power retract the tool relative to the support and manually operable structure is provided for manually projecting and retracting the pilot member relative to the support. Control structure is provided for the power structure operatively associated with the manually operable structure for projecting and retracting the pilot structure for actuating the power structure to project the tool responsive to projection of the pilot structure from a retracted position thereof past a first projected position to a second further projected position and for actuating the power structure to retract the tool responsive to partial retraction of the pilot structure from the second projected position thereof to the first projected position thereof.

The device comprises a central body carrying a first inflatable flexible head and two jacks each carrying an inflatable flexible head at its end. The rods of the jacks are oriented in two directions located on either side of the central body to assure displacement of the central body as a result of the retraction and extension of the rods of the jacks in opposite directions. In the expanded state, the inflatable flexible head are maintained by wedging in the annular space between the bundle casing and the outer casing of the steam generator. In the retracted and deflated state, the flexible heads can be displaced in the annular space. The device also comprises an assembly for guidance by rolling on the lower end of the bundle casing of the steam generator.

A vehicle of the invention comprises at least two transfer arms including means for causing expansible positioning fingers to penetrate into the tubes of a steam generator and for extracting said fingers from said tubes. The vehicle also includes at least two pivoting fastening heads which contain said expansible positioning fingers. The heads are interconnected by one of the telescopic transfer arms, which arms extend perpendicularly to said pivoting heads. The other telescopic transfer arm is fixed to one of the heads and it extends perpendicularly therefrom with its opposite end carrying a tool support. Such a vehicle is particularly suitable for inspecting and maintaining tubes in tube apparatuses, e.g. the steam generators of pressurized water nuclear reactors.