AIR CONTROL MEANS

摘要

AIR CONTROL MEANS Air control means in a gas turbine engine having a variable pitch rotatable airfoil and means for varying the pitch of the airfoil are disclosed. The air control means comprise a platform fixedly attached to a radially inner end of the airfoil. The platform is generally positioned on a rotatable annular surface, which surface defines outer and inner spaces. In a first position, an edge portion of the platform substantially conforms to the annular surface. In a second position, the edge portion is displaced radially outwardly from the surface thereby allowing fluid communication between the outer and inner spaces.