Abstract: The invention provides a novel sealing device and plenum assembly particularly adapted for forming a plenum inwardly of a circumferential stator blade array in a gas turbine engine. A Tangential On Board Injection plenum (T.O.B.I.) is defined by assembly of: a forward plate; a rearward plate; and a segmented inner shroud disposed between the forward and rearward plates. Releasable elongate fasteners are disposed in joints between a series of inner shroud segments with sealing sheaths laterally surrounding the fasteners. While clamping the shroud segments between the forward and rearward plates, the fasteners and sheaths simultaneously seal the joints and secure the inner shroud segments with forward and rearward plates in a rigid structural assembly.

Abstract: A method and assembly useful in metal joining processes is disclosed which blocks the deposition of molten metal in openings. The method and assembly employs mica material with a binder to block the flow of molten metal. In one detailed embodiment, the mica material supports elements of the articles being brazed.

Abstract: A turbine spline seal includes an elongated turbine seal member. The seal member has an elongated, imperforate, and manually-flexible first portion and a manually-rigid second portion lengthwise adjoining the first portion. The turbine assembly includes the turbine spline seal and also includes first and second turbine members. The first and second turbine members are spaced apart to define a fluid-path leakage gap therebetween, and the seal member is placed in the gap. Each lengthwise edge of the seal member engages a respective one of two opposing surface grooves of the first and second turbine members.

Abstract: A turbine assembly having a turbine stator, a ceramic inner shroud, and a first spring. The stator has a longitudinal axis and an outer shroud block with opposing and longitudinally outward facing first and second sides. The first side has a longitudinally outward projecting first ledge and has a first side portion located radially outward of the first ledge. The ceramic inner shroud has a first hook portion longitudinally and radially surrounding the first ledge. The first spring is attached to one of the first side portion and the first hook portion and unattachedly and resiliently contacts the other of the first side portion and the first hook portion.

Abstract: Seal plates for gas turbine stationary blade inner shrouds are made in a double cross type seal structure with a view to enhance sealing ability. Seal plates 1, 2 are mutually lapped and disposed in a turbine axial direction between inner shrouds 12 of stationary blades 11. End portion seal plate 5 is lapped on an end portion of the seal plate 2 and end portion seal plate 6 is lapped under an end portion of the seal plate 1. All these seal plates are fitted with their side end portions being inserted into groove 9a provided in the inner shrouds 12. Seal plates 3, 4 and seal plates 7, 8 engaged with the seal plates 3, 4 are also fitted between flange portions of the inner shrouds 12 with their side end portions being inserted into grooves 10a, 10b and grooves 9b, 9c, respectively.

Abstract: The flow path shroud includes a plurality of generally channel-shaped shroud segments having forward and rearward rails interconnected by a flow path section along radial innermost portions of the rails. The volume bounded by the forward and rear rails and flow path sections is unbounded at the ends and the shroud therefore is without side walls. The free ends of the front and rear rails have relief cuts such that thermal induced bowing of the front and rear rails in the axial direction limits the mechanical stress applied to the turbine casing hooks. The thickness of the front and rear walls lies in an approximately 1:1 thickness ratio with the thickness of the flow path section.

Abstract: A gas turbine stationary blade unit in which two stationary blades are formed in a single segment by divided shrouds functions to lessen the occurrence of cracks. Two stationary blades 1a, 1b are fixed to an outer shroud and an inner shroud, respectively. Each shroud is divided into two sections 2a, 2b and 3a, 3b. Flanges 4a, 4b are provided to connect the section together by bolts via boltholes 7. Likewise, flanges 5a, 5b are provided to form a similar connection or joint. If the two stationary blades 1a, 1b are fixed in a single segment by the shrouds which are not divided, a restraining force becomes larger, local stress occurs due to thermal stress and the frequency of crack occurrence increases. However, since the shrouds are divided respectively into two parts and jointed together by bolts, the crack occurrence is lessened. Also, pinholes are provided in opposing faces at the divided portion of the shrouds.

Abstract: A variable diameter shroud ring (21) for the turbine of a gas turbine engine (10) comprises a support structure (25) which carries an annular array of circumferentially spaced apart ceramic segments (26). The radially outer surfaces of the segments (26) are overlaid by a plurality of circumferentially extending metallic sheets (38). The sheets (38) serve to inhibit gas leakage through gaps between the segments (26) as the diameter of the shroud ring (21) is varied.

Abstract: This seal (6) running between gaps (6) between two stator sectors of a gas urbine engine is made up of several thin flexible slabs, capable of sliding one over the other, which gives a better seal.

Abstract: A seal assembly for a turbine blade tip shroud including a one-piece bent metallic sheet inter-segment seal having an axial component and a vertical component adapted to fit in a groove formed in the end walls of each shroud segment, wherein the shroud segment has a platform and radially extending ribs, and the seal fits tightly in the groove providing an axial and a radial component to the seal. A ring seal is also provided for sealing a joint between the shroud and a mounting structure where an annular gap is formed having an "L" shaped cross-section, the ring seal having a "C" shaped configuration and one of the legs of the "C" extending within an axial component of the "L" shaped gap. The leg has a wave pattern with the peaks of the wave in contact with opposite radial walls of the axial component of the gap for creating a gas seal at the joint.

Abstract: A sealing element seals a gap which may be formed between two components that are movable thermally relative to one another. Each component has a component groove located one opposite the other. The sealing element is directed along a center line, in a cross-section essentially perpendicular to a main line, and has a first end, a second end located opposite the first end and a toothed middle region located between the ends. The sealing element is suitable in particular for sealing off a gap between guide blades at high temperatures in a gas turbine plant for the purpose of preventing a gas flow out of a cooling-gas region into a hot-gas region. A gas turbine plant is provided with the sealing element for sealing the gap.

Abstract: An assembly for improving the operation of a gas turbine engine having an annular turbine support case and a plurality of shroud segments supported on the inner, radial side of the turbine support case. The shroud segments are located end-to-end to form an annular shroud within the turbine support case. Slots are provided in each of the adjacent ends of adjacent shroud segments, and seals are provided for insertion in the slots for sealing the gaps between the adjacent ends of adjacent shroud segments. The seals further include extensions which cooperate with the turbine support case to prevent rotation of the shroud segments relative to the turbine support case.

Abstract: A seal for stator vane segments within a gas turbine engine is provided which includes an axial member and an end member. The axial member includes a central portion and at least one axial joint element extending out from the central portion. The central portion has across-section which includes a pair of substantially u-shaped circumferential ends connected by an arcuate midsection. The axial joint element transitions from the arcuate midsection to a substantially flat end. The end member includes an end joint element attached to a radial portion. The axial and end joint elements contact each other to prevent leakage therebetween, and also sidably cooperate with each other to accommodate misalignment between the axial member and the end member.

Abstract: A seal joint including a sealing member for sealing segmented components of a gas turbine engine is spaced from the gas path to provide more effective cooling. The segments include radial extension flanges spacing the seal joint from the gas path. Various cooling arrangements are adaptable to the modified segments to provide for open or closed circuit impingement or convection cooling plus film cooling. Excessive thermal gradients are avoided as the entire corner of the segment is evenly cooled. Moreover, air usage at the joint is bounded by seal leakage with no extra dedicated cooling air.

Abstract: A seal assembly for a turbine blade tip shroud including a one-piece bent metallic sheet intersegment seal having an axial component and a vertical component adapted to fit in a groove formed in the end walls of each shroud segment, wherein the shroud segment has a platform and radially extending ribs, and the seal fits tightly in the groove providing an axial and a radial component to the seal. A ring seal is also provided for sealing a joint between the shroud and a mounting structure where an annular gap is formed having an "L" shaped cross-section, the ring seal having a "C" shaped configuration and one of the legs of the "C" extending within an axial component of the "L" shaped gap. The leg has a wave pattern with the peaks of the wave in contact with opposite radial walls of the axial component of the gap for creating a gas seal at the joint.

Abstract: A seal assembly for a turbine blade tip shroud including a one-piece bent metallic sheet inter-segment seal having an axial component and a vertical component adapted to fit in a groove formed in the end walls of each shroud segment, wherein the shroud segment has a platform and radially extending ribs, and the seal fits tightly in the groove providing an axial and a radial component to the seal. A ring seal is also provided for sealing a joint between the shroud and a mounting structure where an annular gap is formed having an "L" shaped cross-section, the ring seal having a "C" shaped configuration and one of the legs of the "C" extending within an axial component of the "L" shaped gap. The leg has a wave pattern with the peaks of the wave in contact with opposite radial walls of the axial component of the gap for creating a gas seal at the joint.

Abstract: A turbine nozzle includes a circumferentially continuous annular outer band, and a plurality of circumferentially spaced apart vanes extending radially inwardly therefrom. A circumferentially segmented inner band is joined to the vanes and is disposed coaxially with the outer band. The inner band includes a plurality of circumferentially adjoining arcuate segments, adjacent ones of which have circumferentially facing end faces spaced apart to define a gap therebetween. In an exemplary embodiment, strip seals are inserted in corresponding slots formed in the end faces to seal leakage therebetween.

Abstract: A seal for gas turbines includes first and second ends and a central section. The end sections have a greater thickness than the central section, thereby forming a recess about the central section. The ends are constructed using two offset radii such that they are substantially oblong-shaped to obtain an improved engagement capability. A filler material is provided in the recess to reduce the tendency of the seal to flop over at assembly.

Abstract: A turbine shroud hanger includes forward and aft radially outer hooks for mounting the hanger to an annular shroud support, and forward and aft radially inner hooks for supporting a shroud panel radially above a plurality of turbine rotor blades for controlling tip clearance therebetween. The hanger forward outer hook has a radially outer land defined by a pair of pads at distal ends of the hook, with a ridge extending circumferentially therebetween. The outer land is interrupted by a central recess extending between the pads and aft from the ridge to a distal edge of the hook. The forward outer hook has a predetermined radial height which is predeterminedly larger than the radial height of the corresponding forward slot in the shroud support for effecting an interference fit at least in part at the pair of pads to provide a seal against leakage of bleed air.

Abstract: Adjacent platforms (16) have feather seals (34) in complementary slots (22). Hot grooves (40) carry cooling air across the seal and discharge it into the gap (20) between adjacent platforms. Grooves discharging from abutting surfaces are staggered and have a flow component parallel to the axial gas flow through the turbine.

Abstract: A turbine nozzle vane assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and being attached to conventional metallic components. The metallic components having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the turbine nozzle vane assembly. The turbine nozzle vane assembly includes an outer shroud and an inner shroud having a plurality of vanes therebetween. Each of the plurality of vanes have a device for heating and cooling a portion of each of the plurality of vanes. Furthermore, the inner shroud has a plurality of bosses attached thereto. A cylindrical member has a plurality of grooves formed therein and each of the plurality of bosses are positioned in corresponding ones of the plurality of grooves.

Abstract: A gas turbine engine's nozzle structure includes a nozzle support ring, a plurality of shroud segments, and a plurality of airfoil vanes. The plurality of shroud segments are distributed around the nozzle support ring. Each airfoil vane is connected to a corresponding shroud segment so that the airfoil vanes are also distributed around the nozzle support ring. Each shroud segment has a hook engaging the nozzle support ring so that the shroud segments and corresponding airfoil vanes are supported by the nozzle support ring. The nozzle support ring, the shroud segments, and the airfoil vanes may be ceramic.

Abstract: A turbine engine stator has a metal casing surrounding an envelope carrying bearings for the pivots of pivoting blades. A control mechanism for setting the position of the blades includes a radial spindle to which are transmitted the thrust forces of the gases, the envelope being advantageously formed from angular sectors of axially juxtaposed flanges or rings and which are not loaded. Therefore, the bearings are not subject to wear giving rise to gas leaks and efficiency losses. Advantageously, the envelope is made from a composite material.

Abstract: A shroud segment for a gas turbine engine includes a hook having an undercut surface. Various construction details are developed that provide a segment having a hook with minimized bending stress. In a particular embodiment, a shroud segment includes a plurality of hooks spaced along the leading and trailing edges of the shroud segment. Each of the plurality of hooks includes a positioning surface, a support surface and an undercut surface therebetween. The positioning surface defines the limits of axial movement of the shroud segment. The support surface reacts the radial loading on the shroud segment during operation of the gas turbine engine. The undercut surface is offset from the stator assembly to define the maximum length of the support surface.

Abstract: An expandable ceramic tile housing for a high temperature engine is disclosed wherein each tile is independently supported in place in an interlocking matrix by retention mechanisms which mechanically couple the individual ceramic tiles to an outer metal support housing while maintaining thermal isolation of the metal housing from the ceramic tiles. The ceramic tiles are formed with either an octagonal front face portion and a square shank portion or a square front face portion with an octagonal shank portion. The length of the sides of the octagonal front face portion on one tile is equal to the length of the sides of the square front face portion of adjoining tiles to permit formation of an interlocking matrix. Fibrous ceramic sealing material may be placed between radial and tangential facing surfaces of adjacent tiles to limit radial gas flow therebetween.

Abstract: In a gas turbine having a plurality of vane carrier segments (2, 2') suspended coaxially in a machine casing (3) the guide vanes (11, 11') are held by their roots (14, 14') in such a manner that the root (14) of each guide vane engages in each case in two vane carrier segments (2, 2') adjoining one another in the axial direction. The roots (14) of the guide vanes (11) are provided with a collar (15) which extends in the axial direction to the inlet plane (16) of the rotor blade (12) lying upstream. The collar makes a seal there against the root (14') of another guide vane (11').

Abstract: A turbine shroud segment includes a center hook along one edge which retains the segment to the turbine structure while permitting thermal distortion of the segment. In a particular embodiment, a segment includes a pair of spaced center hooks, a first lateral hook, and a second lateral hook disposed oppositely of the first lateral hook. The spaced center hooks retain the segment and prevent radially inward movement of the center region of the segment. The lateral hooks provide supplemental retention while permitting the lateral edges of the segment to move radially outward in response to thermal distortion of the segment.

Abstract: A cooling enhancement for a gas turbine engine blade outer air seal is made up of a plurality of arcuate seal segments, and each one has one or more internal cooling passages. Each segment has a supply surface opposite and in spaced relation to a sealing surface, and first and second end surfaces extending from the sealing surface to the supply surface. Each of the end surfaces includes a substantially planar perpendicular surface and a substantially planar canted surface intersecting at an included angle of between 100 degrees and 140 degrees, and the supply surface has a plurality of cooling orifices adjacent the second end surface. At least one cooling passage extends from the first end surface towards the second end surface, and each cooling passage intersects the first end surface and terminates short of the second end surface. Each cooling passage communicates with the supply surface through at least one of the cooling orifices.

Abstract: A turbine nozzle support assembly includes nozzle segments each having an inner band with an integral retention flange extending radially inwardly therefrom. A plurality of retention tabs extend radially inwardly and are spaced axially aft of the retention flange to define a capture slot therebetween. A nozzle support includes a radially outwardly extending upper flange having a plurality of support pins extending axially, forwardly therefrom and disposed in complementary retention apertures in the retention flanges of the nozzle segments. A retention key is disposed in the capture slot axially between the upper flange and the retention tabs for axially retaining the nozzle segments on the nozzle support.

Abstract: An arrangement for sealing structural members particularly in the case of turbo-engines is provided. A structural member is to be divided along a first plane into segments, which can be moved relative to one another, and is to be movable in a second plane which is angularly offset with respect to the first plane. Projections of the segments sealingly engage in a groove of an additional structural member. Expansion gaps, which are arranged between abutting edges of the segments, are to be sealed off longitudinally and transversely with respect to the course of the gap by sealing plates. In this case, each expansion gap is to be sealed off between a sealing plate arranged transversely to the course of the gap and an opposing surface of the groove acting as a sealing surface by means of a V-shaped insert.

Abstract: In a gas turbine engine, a system for maintaining uniform circumferential spacing between adjacent segments of a compressor liner, the liner segments being retained within an outer casing by a flanged connection. The system includes a T-shaped pin retained within the flanged connection radially and circumferentially by engagement with a slot formed in the outer casing, and axially by engagement with a notch formed in the adjacent liner segment, such that the liner segment overlaps the positioning pin. In a preferred embodiment, each liner segment is notched and held in place by a pin which, in turn, is retained within a slot in the compressor casing.

Abstract: A spacer band for maintaining uniform spacing between adjacent compressor liner segments comprising two segments having a plurality of locking fingers extending from the band for engaging the casing at both ends of the liner segments and in the middle of the segments. The spacer band is located in a vertical channel located along an edge of each liner segment. The vertical channel is defined by a plurality of vertical flanges and a horizontal flange located on the edge of each liner segment. The horizontal flange has notches for receiving said locking fingers.

Abstract: A guide vane ring having guide vanes is provided on two rings which are arranged coaxially and radially at a distance from one another. These two rings are held on assigned housing sections which are subjected to thermally different expansions. One ring is rigidly connected with the guide vanes, and the other ring is connected with the free ends of the guide vanes by the compressive force of a tensioning element. In addition, the other ring is divided into several piston-ring-type elements which axially follow one another and which are each slotted approximately axially and form a cylindrical sliding surface for the whole free ends of the vanes. The tensioning element is arranged on the one group of assigned housing sections while forming a radial compressive force distributed uniformly on the elements.

Abstract: A compressor outlet guide vane (OGV) assembly includes inner and outer annular OGV walls, having outlet guide vanes mounted therebetween, are in abutting relationship with the corresponding leading edges of respective inner and outer diffuser casings and not welded to or otherwise supported by the leading edges of the diffuser casings as in the prior art. The OGV assembly is attached to an annular OGV support member that extends from a portion of a corresponding OGV wall circumscribing the thick section of the OGVs. This assembly decouples the inner and outer OGV annular walls from moments or thermally induced radial loads that may be transferred to the OGV walls due to the interface of the diffuser casings and OGV walls and which may in turn induce failure causing stresses in the OGV trailing edges.

Abstract: A locator pin retention device comprises a pin with threaded and smooth portions cooperating with a bushing having spaced apart threaded and smooth portions to allow alignment of inner and outer gas turbine engine members exposed to different thermal environments, allowing thermal growth of the inner member in a radially outward direction toward the outer member and reacting axial and circumferential loads to prevent transverse movement to the outer structural member. The device reduces machining of the structural members because machined retention means are inexpensive and replaceable parts.

Abstract: A gas turbine engine is provided with an annular array of rotor blades which are surrounded by a shroud ring. The shroud ring includes a number of adjacent heat pipes which are of the variable conductance type. The heat pipes each have a portion which is externally of the shroud ring which portion is in turn divided into two parts. The first part is exposed to a flow of cooling air while the second part contains a buffer which operationally varies the conductance of the heat pipe, in accordance with the temperature of air which is tapped from the high pressure compressor of the engine. This serves to ensure that the shroud ring remains substantially isothermal and provides control over the clearance between the tips of the rotary blades and the shroud ring through thermal control of the shroud ring.

Abstract: A clearance control assembly in a gas turbine engine includes several stages of cylindrical turbine shroud rings and a one-piece continuous cylindrical housing surrounding the shroud rings in radially outward spaced relation. Each shroud ring is composed of at least a pair of semi-cylindrical segments mounted to the housing. The shroud ring segments are radially positioned by thermal expansion and contraction of the housing in response to temperature-controlled air flow between the housing and shroud segments. Coupling elements joins together opposite edge portions of adjacent shroud ring segments to permit axial movement of the shroud segments toward and away from one another. Lands which protrude outwardly from the housing interior and shroud ring segment exteriors are located between the housing and shroud segments for defining several spiral channels for air flow about the interior of the housing and exterior of the shroud segments.

Abstract: A joint connection for abutting, circumferentially extending segments in a gas turbine engine, such as turbine nozzle segments, includes a sealing member which is insertable between longitudinally extending slots formed in the abutting side edges of two adjacent segments. The segments are each formed with a number of grooves which are longitudinally spaced along the length of the slots therein, and which extend beneath the sealing member carried within the slots. A cooling air flow path is thus formed extending from one side of the sealing member, into the longitudinal slot of each segment and then through the grooves to the opposite side of the sealing member so that the entire joint connection or seal region between the abutting side edges of the segments is cooled.

Abstract: A compressor discharge flowpath for a gas turbine engine includes flowpath outer and inner walls joined to a plurality of circumferentially spaced flowpath dividers extending therebetween. An inner support extends from the inner wall and is joined to a turbine nozzle, and an outer support extends from the outer wall and is joined to an engine casing. The outer support preferably includes a plurality of circumferentially spaced beams being sized and configured for carrying both axial force and torque transmitted therethrough from the turbine nozzle to the casing while allowing the beams to bend radially for accommodating differential thermal movement between the casing and the outer wall.

Abstract: A "dog bone" in cross section shaped seal mounted in adjacent grooves of segmented stator vanes span the axial extent covering a single casted three rows of vanes. The outer diameter shroud of the stator vane defines a portion of an enclosed cavity subjected to leakage flow in and out of the gas path where the flow reverses at some axial extent of the seal such that the forces acting at different locations on the seal reverses. In a preferred embodiment, the bulbous ends of the "dog bone" are solid coated metallic material.

Abstract: The stator blades (10) are made of a thermostructural composite material and have asymmetric inner and outer roots (14, 16) such that at least one of the roots of an a blade presses against the outer side (12b) or inner side (12b) of a neighboring blade. Also, each root (14, 16) of each blade presses against the adjacent ring by a part only of its external surface, thereby allowing some flexing of the root under the effect of differential expansion between the blade and the ring.

Abstract: An apparatus for effecting a seal between two structural components of a turbo machine or similar device comprises a leaf seal located in the space between the two components and a spring which continuously biases the leaf seal into a sealing position against the components regardless of the pressure differential across the leaf seal.

Abstract: To prevent overheating of the gaps between shroud segments circumferentially arranged about a high pressure turbine rotor, an improved seal is provided to block radial leakage flow of hot working gas through the gaps, as well as to restrict axial flow of working gas in the gaps. The seal includes a corrugated, axial fluid flow restricting element sandwiched between a pair of radially spaced, gap spanning shim sealing elements. Pressurized cooling air is admitted to the gap at locations between the shim sealing elements via passages through adjacent shroud segments to cool the gap and to further restrict working gas axial flow in the gap.

Abstract: A stator ring assembly for a turbine comprising a plurality of sections, each section has a first sheet metal portion being connected to a second sheet metal portion, and a support ring of generally S-section defining a radially outer edge portion of the second sheet metal portion co-operating with the support ring.

Abstract: An annular cast inner support member is concentrically mounted within an annual cast outer support member for mounting a plurality of radially extending outlet guide vanes within the flowpath of a gas turbine engine. The outlet guide vanes are resiliently connected to the inner and outer support members to control and limit the compressive loading of the outlet guide vanes caused by thermal stresses during engine operation. A resilient clamped interconnection which is particularly suitable for use with ceramic outlet guide vanes includes a bolted and clamped socket assembly which maintains both radial and circumferential compressive forces on the outlet guide vanes at all times, notwithstanding the differences in thermal growth rates between metal and ceramic materials.

Abstract: A stator vane assembly 30 for a rotary machine is disclosed. The stator vane assembly includes an array of stator vanes 44 and an inner air seal 46. Various construction details which damp vibrational stresses in the vanes are developed. In one embodiment, the stator vanes slidably engage the inner air seal. The inner air seal is urged radially into sliding contact with the vanes at the inner ends 52 of the vanes by a resilient device such as a radial spring member 70. In one detailed embodiment, the stator vane has at least two airfoils 55b,c which are circumferentially spaced at their inner ends leaving a circumferential gap therebetween.

Abstract: A gas turbine with at least one fixed guide vane ring (1) with a sealing ring (3) cooperating with a sealing member on the turbine rotor (7). The sealing ring (3) is connected to the guide vane ring (1) through a number of links (19) which are suitably oriented in a substantially tangential direction. The attachment of the sealing ring (3) by means of the links (19) means a perfect centering of the sealing ring (3) relative to the rotor (7) when the guide vane ring (1) expands relative to the sealing ring (3).

Abstract: A stator assembly for a gas turbine engine having a support structure and a stiffening ring 46 extending about the support structure 34 is disclosed. Various construction details which increase the rigidity of the support structure and enable the stiffening ring to accept axial and radial loads are developed. In one embodiment the stiffening ring 46 is the seal ring 52 for a seal end 74. In one particular embodiment, the thermal expansion characteristic of the support structure is greater than the thermal expansion characteristic of the stiffening ring to insure that the stiffening ring is in tension under normal operative conditions of the engine.

Abstract: A dish-shaped wheel having an essentially slot-shaped conically extending cutting tip with the tip extending angularly from the wheel surface. The tip includes a super abrasive plating suitable for nondressable cutting such as cubic boron nitride. The wheel is of sufficient diameter to cut an ellipse approximating the arc to be formed as the wheel moves in an arc through the article. The apparatus further includes mechanism for orienting the wheel, mechanism for rotating the wheel and mechanism for translating the wheel or the article in a desired arc for producing a curved slot. The apparatus has particular application for producing narrow curved featherseal slots in turbine vane platforms, allowing increased complexity in vane design while enhancing seal integrity.

Abstract: A steam turbine having a seal, connected between the annular rows of stationary blades positioned proximate the turbine inlet, for preventing the circumvention of the flow of steam from the desired flow path and for preventing the transfer of thermal loads between the rows of stationary blades. The seal includes a band connected to one of the stationary annular row of blades and extending across the inlet, a support piece connected to the other stationary annular row of blades, and a resilient seal connected to the support piece and positioned to be in frictional engagement with the band.