US Patent 7198472 Platform mounted components

A platform arrangement for components such as aerofoil vanes 1, 21 is provided whereby the necessary rigidity provided by the platform does not create excess problems with respect to stress and strain fatigue failure at thinner sections of the component. The leading edge 6, 26 and trailing edge 7, 27 of a vane generally have a thinner section and so when subject to greater flex deformation such flex deformation may lead to premature failure through stress and strain. Structural configurations are now provided which comprise cut out windows 24 in the platform 22 beneath the edges 26, 27 or alternatively differential material types at these locations with a less stiff nature. Generally, a backing member 25 is provided below an integral platform layer 22 to create generally greater stiffness in the platform unit formed by the combination but in accordance with the present invention this backing member 25 may include the cut out windows 24 or have the necessary differential material types for variable flexibility compliance at portions of reduced component cross-section.