Patent ID: 8491254

Claim:
A turbomachine compressor comprising: an annular casing; and at least one nozzle stage including an annular row of variable-pitch vanes, each comprising an airfoil connected at at least one end via a plate of substantially circular outline to a radially-extending cylindrical pivot guided in pivoting in a corresponding orifice in the casing, each vane being pivotable about an axis defined by the pivot of the vane between a first position and a second position, wherein the plates of at least some of the vanes include respective ducts for feeding air to respective passages formed in the casing, each passage including one end opening out into an annulus of the compressor to inject air into the annulus upstream from the vane, the feed duct formed in the plate including one end communicating with the corresponding passage in the casing when the vane is in the first position, and being closed by the casing when the vane is in the second position, so that a rate at which air is injected depends on a pitch angle of the vanes.