Patents by Inventor Lawrence P. Ludwig
Lawrence P. Ludwig has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 4295786Abstract: A gas path seal suitable for use with a turbine engine or compressor is provided. A shroud wearable or abradable by the abrasion of the rotor blades of the turbine or compressor shrouds the rotor blades. A compliant backing surrounds the shroud. The backing is a yieldingly deformable porous material covered with a thin ductile layer. A mounting fixture surrounds the backing.Type: GrantFiled: November 20, 1979Date of Patent: October 20, 1981Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Robert C. Bill, Lawrence P. Ludwig
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Patent number: 4266788Abstract: A circumferential shaft seal comprising two sealing rings held to a rotating shaft by means of a surrounding elastomeric band. The rings are segmented and are of a rigid sealing material such as carbon or a polyimide and graphite fiber composite.Type: GrantFiled: December 7, 1979Date of Patent: May 12, 1981Assignee: The United States of America as represented by the Administrator, National Aeronautics and Space AdministrationInventor: Lawrence P. Ludwig
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Patent number: 4212477Abstract: A circumferential shaft seal comprising two sealing rings held to a rotating shaft by means of a surrounding elastomeric band. The rings are segmented and are of a rigid sealing material such as carbon or a polymide and graphite fiber composite.Type: GrantFiled: March 31, 1976Date of Patent: July 15, 1980Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventor: Lawrence P. Ludwig
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Patent number: 4207024Abstract: A gas path seal suitable for use with a turbine engine or compressor is provided. A shroud wearable or abradable by the abrasion of the rotor blades of the turbine or compressor shrouds the rotor blades. A compliant backing surrounds the shroud. The backing is a compliant material covered with a thin ductile layer. A mounting fixture surrounds the backing.Type: GrantFiled: August 4, 1978Date of Patent: June 10, 1980Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Robert C. Bill, Lawrence P. Ludwig
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Patent number: 4145058Abstract: A seal assembly is provided for reducing the escape of fluids from between a housing and a shaft rotatably mounted in the housing. The seal assembly comprises a pair of seal rings resiliently connected to each other and disposed in side-by-side relationship. In each seal ring, both the internal bore surface and the radial face which faces away from the other seal ring are provided with a plurality of equi-spaced recesses known as Rayleigh step pads. The seal faces referred to are located adjacent a seating surface of the housing. Under normal operating conditions, the seal assembly is stationary with respect to the housing, and the recesses generate lift, keep the assembly spaced from the rotating shaft and allow slip therebetween. Due to expansion of the shaft resulting from rubbing contact with the seal assembly, the seal assembly can seize on the shaft, and slip will then occur between the radial faces and the housing.Type: GrantFiled: July 8, 1977Date of Patent: March 20, 1979Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: William F. Hady, Lawrence P. Ludwig
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Patent number: 4135851Abstract: A gas path seal suitable for use with a turbine engine or compressor is provided. A shroud wearable or abradable by the abrasion of the rotor blades of the turbine or compressor shrouds the rotor blades. A compliant backing surrounds the shroud. The backing may be made of corrugated sheets or the like with adjacent layers having off-set corrugations, with axes of the folds parallel to the rotor axis. The sheets may be bonded together at points of contact by brazing, welding or the like. In another embodiment a compliant material is covered with a thin ductile layer. A mounting fixture surrounds the backing.Type: GrantFiled: May 27, 1977Date of Patent: January 23, 1979Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: Robert C. Bill, Lawrence P. Ludwig
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Patent number: 4084825Abstract: This application discloses a dirt separator and excluder for removing entrained debris from gas turbine shaft seals. A helical groove pattern is constructed on the rotating shaft with the pumping pattern such that it tends to pump seal pressurizing gas toward the gas turbine seal. A second helical groove pattern is provided on the stationary housing or counter rotating member coaxial with the shaft, and this pattern is designed to provide pumping in the direction opposite from that of the groove pattern on the shaft. Gas with entrained debris entering this grooved area will be subjected to high centrifugal forces due to the swirl motion induced by the groove pattern and the rotation of the shaft. This debris is centrifuged outwardly into the outer groove pattern on the housing or counter rotating member. Since the outer groove pattern has a pumping direction opposite from that of the seal, dirt is pumped away from the seal and can be collected in a suitable debris trap remote from the seal location.Type: GrantFiled: March 31, 1976Date of Patent: April 18, 1978Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventor: Lawrence P. Ludwig
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Patent number: 3953038Abstract: An improved fluid seal for a rotating shaft is provided which includes an inner annular ring or runner adapted to be secured to the rotating shaft and a composite sealing ring which is keyed to the inner ring and includes a radial sealing surface. An outer, nonrotating, annular ring or housing which is concentrically disposed with respect to the runner and sealing ring, includes a radial sealing surface which sealingly engages the sealing surface of the sealing ring.A circular wave spring, which is anchored to the housing and is disposed between the composite sealing ring and a snap ring secured to the housing, provides an axial force which forces the two sealing surfaces into sealing contact. The waves of the spring act as individual hydrodynamic bearings, and the axial force is transmitted across an oil film. This eliminates rubbing contact and the need for a separate thrust bearing.Type: GrantFiled: February 19, 1975Date of Patent: April 27, 1976Assignee: The United States of America as represented by the United States National Aeronautics and Space AdministrationInventor: Lawrence P. Ludwig