Patents Represented by Attorney, Agent or Law Firm Jeffrey W. Astle
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Patent number: 5971703Abstract: 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.Type: GrantFiled: December 5, 1997Date of Patent: October 26, 1999Assignee: Pratt & Whitney Canada Inc.Inventor: Guy Bouchard
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Patent number: 5961278Abstract: An outer housing for supporting a stator assembly in a gas turbine engine, wherein the support includes two outer ring sections between which the vane segments of the stator assembly are mounted to form a ring within the cylindrical support. A central ring section is provided between the outer ring sections and is connected thereto by means of spokes. The central ring section locates the structure within the engine casing. The spokes extend at an angle to the axis of the stator assembly and define openings therebetween whereby thermal distortion between the outer rings and the central ring is attenuated.Type: GrantFiled: December 17, 1997Date of Patent: October 5, 1999Assignee: Pratt & Whitney Canada Inc.Inventors: Francois Dorais, Guy Bouchard
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Patent number: 5881995Abstract: A noise attenuating device for reducing the noise generated by a gas flow passing through an open butterfly valve having a disc pivotally mounted in a valve housing for rotation about a transversal axis between an open and a closed position thereof. The noise attenuating device comprises a first series of elongated members extending from the upstream side of the disc above the transversal axis and a second series of generally diametrically opposed elongated members extending from the downstream side of the disc below the horizontal axis. Typically, the elongated members extend at 45 degree from the disc of the butterfly valve.Type: GrantFiled: December 15, 1997Date of Patent: March 16, 1999Assignee: Pratt & Whitney Canada Inc.Inventors: Man-Chun Tse, Hilaire Bonneau
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Patent number: 5862666Abstract: A modified turbine engine design in which control of the forward load on a thrust bearing is improved, while reducing or eliminating the need for the use of a balance piston is disclosed. The turbine engine has a longitudinal axis and comprises, a compressor for pressurizing gases in the engine. The impeller has an impeller rear face and a tip. The engine further comprises a shaft mounted to a thrust bearing for rotation about the axis. The impeller is fixed to the shaft for rotation therewith. A cavity fixed within the engine casing is defined at least by the impeller rear face and is in communication with the pressurized gases at the impeller tip. The engine further comprises a bleed in communication with both the cavity and the pressurized gases, so that the cavity is pressurized by the pressurized gases from the impeller tip and the bleed, thereby loading the impeller rear face to load the thrust bearing through the shaft.Type: GrantFiled: December 23, 1996Date of Patent: January 26, 1999Assignee: Pratt & Whitney Canada Inc.Inventor: Xiaoliu Liu
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Patent number: 5779437Abstract: A cooling structure for the leading edge area of an airfoil having a plurality of passages wherein each passage has a radial component and a downstream component relative to the leading edge axis, and the outlet of each passage has a diffuser area formed by conical machining, wherein the diffuser area is recessed in the wall portion downstream of the passage.Type: GrantFiled: October 31, 1996Date of Patent: July 14, 1998Assignee: Pratt & Whitney Canada Inc.Inventors: William Abdel-Messeh, Ian Tibbott, Subhash Arora
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Patent number: 5762472Abstract: 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.Type: GrantFiled: March 27, 1997Date of Patent: June 9, 1998Assignee: Pratt & Whitney Canada Inc.Inventors: Antonio Pizzi, James Christopher Crone
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Patent number: 5738490Abstract: 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.Type: GrantFiled: May 20, 1996Date of Patent: April 14, 1998Assignee: Pratt & Whitney Canada, Inc.Inventor: Antonio Pizzi
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Patent number: 5711650Abstract: A cooling system for airfoil vanes in a turbine of a gas turbine engine wherein the airfoil platforms have openings downstream of the insert tube for passing spent platform impingement coolant air into the airfoil cavity downstream of the insert tube to increase the pressure in the aft zone of the airfoil to improve the temperature gradient across the span of the airfoil.Type: GrantFiled: October 4, 1996Date of Patent: January 27, 1998Assignee: Pratt & Whitney Canada, Inc.Inventors: Ian Tibbott, William Abdel-Messeh, Michael Papple
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Patent number: 5603602Abstract: A pressurized bearing assembly for turbomachines like gas turbine engines wherein pressurized oil is used to apply an axial force to the outer bearing race of a ball bearing assembly. The force is transmitted through the race to the ball bearings and to the inner race of the bearing assembly, and is further transmitted, via the engine shaft, to the bearings of another, axially spaced apart bearing assembly. The force moves the balls in both assemblies into line-on-line running contact with their respective bearing races, and minimizes vibration in the assemblies.Type: GrantFiled: August 8, 1994Date of Patent: February 18, 1997Assignee: Pratt & Whitney Canada Inc.Inventor: Giuseppe Romani
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Patent number: 5587630Abstract: A continuous plasma ignition system includes an exciter 12, an ignitor plug 16 and a cable 18 which connects the excitor 12 to the ignitor plug 16. The ignition system operates at the resonant frequency value f.sub.r of the circuit formed by the exciter, ignitor plug and the cable, such that, a continuously plasma 23 of ionized air is provided across the ignitor gap 22.Type: GrantFiled: October 28, 1993Date of Patent: December 24, 1996Assignee: Pratt & Whitney Canada Inc.Inventor: Kevin A. Dooley
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Patent number: 5579645Abstract: A fuel nozzle (18) for a gas turbine engine comprises a nozzle stem (55), a nozzle tip assembly (60) and a nozzle sheath (50). A plurality of inlets (82) allow air to flow into the interior (90) of the sheath (50); fuel is flowed into the nozzle (18) through a fuel passage (135) in fluid communication with a fuel manifold. The fuel enters a fuel channel (140) defined by the stem (55) and tip assembly (60), and then passes into a fuel gallery (185) through a plurality of metering holes (190). Fuel swirls out of the tip assembly (60), where it is caught between, and squeezed by, first and second streams of air passing out of radially spaced apart air passages (145) and (220).Type: GrantFiled: September 6, 1995Date of Patent: December 3, 1996Assignee: Pratt & Whitney Canada, Inc.Inventors: Lev A. Prociw, Alain Bouchard, Pierre Bolduc, Honze Stastny
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Patent number: 5531457Abstract: 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.Type: GrantFiled: December 7, 1994Date of Patent: July 2, 1996Assignee: Pratt & Whitney Canada, Inc.Inventors: Ian Tibbott, Roger Gates
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Patent number: 5518369Abstract: Gas turbine blades 14 are slid axially into disc 12 with a retention tang 22 on each abutting the disc. An axially extending space 28 between blade platforms 26 and the disc receives elongated strip 30. With prebent end 34 resiliently held against the disc the opposite end 36 is bent radially outward against the roots of adjacent blades. A bow 38 biases the blades outwardly, deterring vibration.Type: GrantFiled: December 15, 1994Date of Patent: May 21, 1996Assignee: Pratt & Whitney Canada Inc.Inventor: Mario Modafferi
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Patent number: 5477673Abstract: The present invention discloses a bleed valve for use in gas turbine engines. The valve has a piston, one end of which is positioned inside a housing which is positioned on one side of the by pass fluid flow path. The other end of the piston is positioned in an opening between the primary fluid flow path and the bypass fluid path such that the valve opens and closes in response to a pressure differential between two points in the primary fluid flow path.Type: GrantFiled: August 10, 1994Date of Patent: December 26, 1995Assignee: Pratt & Whitney Canada Inc.Inventors: Daniel Blais, Eric Tremaine, Vasil Ozarapoglu