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In a gas turbine having a chordal hinge seal between an inner rail of each nozzle segment and an annular axially facing sealing surface of a nozzle support ring, a supplemental seal is disposed between the support ring and inner band of the nozzle segment on a lower pressure side of the chordal hing

In a gas turbine having a chordal hinge seal between an inner rail of each nozzle segment and an annular axially facing sealing surface of a nozzle support ring, a supplemental seal is disposed between the support ring and inner band of the nozzle segment on a lower pressure side of the chordal hinge seal. The supplemental seal includes a flexible sheet metal seal having a margin secured in a groove of the inner rail of the nozzle segments with a bent-over edge to form a seal therewith. The opposite margin has an edge which bears against the axially opposed sealing surface of the nozzle support ring. Leakage flow past the chordal hinge seal exerts sealing pressure against the preloaded flexible seal to maintain the seal between the sealing surfaces of the support ring and segments. The supplemental seal extends circumferentially and spans the joint between adjacent nozzle segments.

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In a gas turbine having a chordal hinge seal between an inner rail of each nozzle segment and an annular axially facing sealing surface of a nozzle support ring, a supplemental seal is disposed between the support ring and inner band of the nozzle segment on a lower pressure side of the chordal hing

In a gas turbine having a chordal hinge seal between an inner rail of each nozzle segment and an annular axially facing sealing surface of a nozzle support ring, a supplemental seal is disposed between the support ring and inner band of the nozzle segment on a lower pressure side of the chordal hinge seal. The supplemental seal includes a flexible sheet metal seal having a margin secured in a groove of the inner rail of the nozzle segments with a bent-over edge to form a seal therewith. The opposite margin has an edge which bears against the axially opposed sealing surface of the nozzle support ring. Leakage flow past the chordal hinge seal exerts sealing pressure against the preloaded flexible seal to maintain the seal between the sealing surfaces of the support ring and segments. The supplemental seal extends circumferentially and spans the joint between adjacent nozzle segments. ecreases toward the outlet end thereof. 5. The tool according to claim 1 wherein the end face forms lands between successive ones of the grooves, a total area of the grooves being greater than a total area of the lands, as the areas are seen in a direction perpendicular to the end face. 6. The tool according to claim 1 wherein the end face forms lands between successive ones of the grooves, a total area of the grooves being less than a total area of the lands, as the areas are seen in a direction perpendicular to the end surface. 7. The tool according to claim 1 wherein each groove comprises two spaced apart side surfaces. 8. The tool according to claim 1 wherein each groove further comprise a concave bottom surface interconnecting the side surfaces. 9. The tool according to claim 1 further including a deflector arranged at a front end of the duct for deflecting the fluid flow from the duct to the grooves. 10. The tool according to claim 1 further including air inlet channels formed in the head and extending from the envelope surface to respective ones of the grooves, each air inlet channel intersecting the respective groove at a location adjacent the inlet end thereof. 11. The tool according to claim 2 wherein at least some of the branch ducts are curved from the inlet end to the outlet end thereof as viewed in a direction perpendicular to the end surface. 12. The tool according to claim 11 wherein the curvature of the curved branch ducts is cycloidal. 13. The tool according to claim 7 wherein the side surfaces are parallel to one another as seen in a cross section of each groove. 14. The tool according to claim 7 wherein the side surfaces are non-parallel to the axis as seen in a cross section of each groove. 15. The tool according to claim 7 wherein one of the side surfaces is parallel to the axis, and the other side surface is non-parallel to the axis, as seen in a cross section of each groove. 16. The tool according to claim 7 wherein the side surfaces are divergent from one another in a rearward direction away from the end surface. 17. The tool according to claim 7 wherein the side surfaces are parallel to the axis as seen in the cross section. 18. The tool according to claim 9 wherein at least a portion of each groove is left uncovered by the deflector to be forwardly open. 19. A tool for chip removing machining comprising a rotary head defining a longitudinal axis of rotation, the head including: an envelope surface arranged generally symmetrically relative to the axis; a front end surface extending transversely relative to the axis; a plurality of circumferentially spaced insert seats configured for receiving respective cutting inserts, each insert seat disposed in a transition region between the envelope surface and the end surface; a main duct extending longitudinally within the head for conducting fluid, the main duct intersecting the end surface; a plurality of branch ducts extending generally transversely outwardly from a fluid inlet end thereof communicating with the main duct, the branch ducts extending all the way to respective insert seats for conducting fluid from the main duct to the insert seats, each branch duct defined by a groove machined directly in the front end surface and configured to induce a flow of fluid from a fluid inlet end thereof to a fluid outlet end thereof in response to rotation of the head; and a deflector arranged at a front end of the main duct for deflecting the fluid flow from the main duct to the branch ducts, the deflector arranged on an element removably attached to the end surface. 20. The tool according to claim 19 wherein the element includes a plate and a hollow bushing extending from the plate, the bushing being coaxial with the axis of the head, and including a plurality of holes spaced apart circumferentially with reference to the axis, the holes being aligned with the inlet ends of respective ones of the branch ducts. 21. The tool according to claim 19 wherein