Abstract: The present invention provides: fiber preforms sheathed in a boron nitride coating, said coating (generated on said previously-prepared fiber preforms) having a structure that is original: microporous and granular; thermostructural composite materials in which the reinforcing fabric is constituted by said fiber preforms; and methods of preparing said fiber preforms and said thermostructural composite materials, respectively. The composites of the invention have their fiber preforms, based on fibers (F), sheathed in an original interphase (IBN) and embedded in the densification matrix (M).

Abstract: A tool for removing balance weights attached to the head platform of the blades of a turbine comprises a jointed arm which can be introduced through the exhaust nozzle of the turbine without any disassembly, the arm having a handle portion which is held by the operator carrying out the removal operation, and a distal part which is steerable by movements imparted to the handle portion by the operator, the distal part being dislocatable and articulated with respect to said handle portion and ending in a claw adapted to grip the balance weight and to unseat it without letting it go in response to appropriate movements of the handle portion.

Abstract: A fan or compressor stage rotor comprises a disc, radial blades mounted in axial sockets formed in the periphery of the disc, and spacer blocks interposed between the blades to constitute the inner boundary of the air flow path through the rotor. The spacer blocks each comprise an outer wall which is spaced from the periphery of the disc, and front and rear walls extending radially inwardly to overlap at least partially the front and rear faces of the disc. The front and rear walls each comprise at least one hook which co-operates with a corresponding groove provided in the respective face of the disc to fix the spacer block to the disc. The spacer block also comprises a median partition projecting inwards from its outer wall and having a slot through which passes a leaf spring of a vibration damper.

Abstract: An axial flow turbomachine rotor comprises a disc having a plurality of annular flanges extending outwardly from its periphery, a plurality of blades secured to the disc and extending radially outwardly from the periphery thereof, each of the blades having its root notched to define heels which are received in the grooves formed between the annular flanges of the disc, and a plurality of separate platforms which are secured to the disc and are disposed between the blades to define the inner boundary of the fluid flow path through the rotor, the blades each being fixed to the disc by two parallel pins which are equidistance from the axis of the disc and are received in corresponding bores passing through the annular flanges and the heels of the blade, the pins also serving to secure the platforms to the disc.

Abstract: A fan for a turboshaft engine is disclosed comprising a rotatable disc having an array of blades secured at evenly spaced intervals around its periphery, each pair of successive blades and the disc defining a space which is delimited by the stem and a platform of a first of the two blades, the stem and a platform of the second of the two blades, and the periphery of the disc between the two blades.

Abstract: A system is disclosed for mounting the pre-vaporizing bowl to a wall of a turbine engine combustion chamber in such a manner that it is centered and in alignment with an opening, through the combustion chamber wall during assembly. Not only does the system provide for the centering of the pre-vaporizing bowl in the combustion chamber wall opening, but it also allows relative radial movement between these elements after the engine has been assembled. The system includes a support collar fixedly attached to the combustion chamber wall so as to extend around the generally circular opening in the upstream portion of the combustion chamber, as well as a locating flange fixedly attached to the pre-vaporizing bowl. A stud extending from the locating flange extends through a slot in the support collar such that only radial movement between the locating lfange and the support collar (and consequently between the pre-vaporizing bowl and the combustion chamber wall) is permitted.