Framatome & Cie.

Gerard Crespin

Jean Coussau

A device and process for fixing two parts with a captive screw (5) engaged in a threaded hole (3) machined in at least one of the two parts (1,2). The screw (5) comprises over its whole length a bore (6) communicating with at least one radially directed hole (10) opening out on the outer side surface of the screw (5) in its threaded part (5a) and enclosing a component (11) movable in the hole (10). A maneuvering rod (14) is engaged in the bore (6) for locking the screw (5) in place in the threaded hole (3), by placing a part of the rod with larger diameter to coincide with the component (11) which then crushes the threading of the part (3a) of the hole (3). The rod (14) is crimped over the screw (5) by virtue of strips (18). The disclosure applies in particular to the assembly of two walls of a partitioning of the core of a pressurized water nuclear reactor.

Device and process for fixing two parts with a captive screw

The device includes an electrode in the form of a cylindrical tube, an arrangement for causing an electrical discharge between the electrode and the workpiece, a support fixed to the workpiece and disposed at least partly inside the electrode for guiding the electrode in a direction perpendicular to the workpiece and electromagnetic structure placed inside the electrode to cause the electrode to vibrate.

Device for piercing a hole through a metal workpiece by electrical

Device for calibrating a machine tool including a tool (32) rotating about its axis XX', comprising a tubular-shaped support with an annular fixing component (3) connecting it to the housing (1) of the machine tool so that its central opening forms an extension of the opening (2) of the housing (1) for the passage of the tool (32). The support also has at least one part (18) which is deformable under the action of twisting about the axis XX' and is provided with at least one strain gauge (19), and an end part (12) which is opposite the fixing component (3) and in which there is arranged, along the axis of the support, a component (20) for connecting the end of the tool (32), which component is provided with means (20') enabling locking of said tool in rotation with the connection component. The latter carries a disk (30) located between two annular components (31a and 31b) held against the disk (30 ) by adjustable means (22, 25). As a result of a measuring means associated with the strain gauge (19), a current representing the resisting torque opposing the tool (32) may be measured via the disk (30) and the components (31a and 31b). The invention relates, in particular, to machines for screwing the partitioning of a nuclear reactor core.

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Villeurbanne, France

Gerard Crespin