Patents by Inventor Robert P. Schaefer

Robert P. Schaefer 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).

  • Patent number: 9694440
    Abstract: An example method of attaching an airfoil for an integrally bladed rotor includes placing a support collar in an installed position around at least a leading edge and trailing edge of an airfoil stub to be repaired in an integrally bladed rotor. The support collar and the airfoil stub together have a midline that is positioned between opposing, laterally outer surfaces of the airfoil stub when the support collar is in the installed position. The method performs linear friction welding to add a replacement airfoil to the airfoil stub.
    Type: Grant
    Filed: October 22, 2010
    Date of Patent: July 4, 2017
    Assignee: United Technologies Corporation
    Inventors: James J. Moor, Herbert A. Chin, Greg Czeladko, Gene A. Danko, Andrew L. Haynes, Wangen Lin, Vincent Nevins, Robert P. Schaefer, Eberhardt Privitzer
  • Publication number: 20150190891
    Abstract: A method of repairing defects in a casting formed from non-weldable or difficult-to-weld alloys is disclosed. The method includes removing the defect from the casting thereby forming a cavity in the casting, placing a filler material in the cavity and fusion welding the filler material in the cavity. The fusion welding produces surface cracks on the casting and sub-surface cracks in the casting. The method then includes brazing at least some of the surface cracks on the casting and processing the casting with a hot isostatic pressure (HIP) process to close at least some of the sub-surface cracks in the casting.
    Type: Application
    Filed: July 19, 2013
    Publication date: July 9, 2015
    Inventors: Wangen Lin, Robert P. Schaefer, Chris Vargas
  • Patent number: 8613138
    Abstract: A method is provided for repairing a damaged rotor blade on an integrally bladed rotor by removing a damaged portion of a damaged blade leaving a blade stub extending outwardly from the disk and performing a linear friction welding operation to attach a replacement blade segment to the blade stub. The rotor may be disposed operation using a linear friction welding apparatus. The method includes disposing a support collar about the blade stub and securing the support collar to the linear friction welding apparatus prior to a commencement of the bonding operation. A lower surface of the support collar is contoured to mate with a portion of an outer circumference surface of the rotor disk.
    Type: Grant
    Filed: March 19, 2010
    Date of Patent: December 24, 2013
    Assignee: United Technologies Corporation
    Inventors: Herbert A. Chin, Robert P. Schaefer, Eberhardt Privitzer, Wangen Lin, Billie W. Bunting, James J. Moor, Vincent Nevins, Andrew L. Haynes, Greg Czeladko, Kenneth T. Raczewski
  • Patent number: 8479391
    Abstract: A method of repairing an integrally bladed rotor includes the steps of placing a support collar around at least a leading and trailing edge portions of the blade stub, and performing linear friction welding to add a replacement airfoil to the blade stub. The linear friction welding is generally along a direction between the leading and trailing edges. In addition, the support collar leading and trailing edge portions are connected together.
    Type: Grant
    Filed: December 16, 2009
    Date of Patent: July 9, 2013
    Assignee: United Technologies Corporation
    Inventors: Herbert A. Chin, Robert P. Schaefer, Eberhardt Privitzer, Wangen Lin, Billie W. Bunting, James J. Moor, Vincent Nevins, Jr., Andrew L. Haynes, Greg Czeladko, Kenneth T. Raczewski
  • Publication number: 20120279066
    Abstract: A method is disclosed for welding a first metal to a Ti-6246 alloy airfoil. The method consists of depositing weld metal by fusion welding and reshaping the airfoil to predetermined dimensions. A post weld heat treatment is applied to relieve residual stresses. Surface treatment such as laser shock peening introduces residual surface compressive stresses to enhance the mechanical integrity of the airfoil.
    Type: Application
    Filed: May 6, 2011
    Publication date: November 8, 2012
    Applicant: UNITED TECHNOLOGIES CORPORATION
    Inventors: Herbert A. Chin, Robert P. Schaefer, Andrew L. Haynes, David G. Alexander, Sonia A. Martinez, Wangen Lin
  • Publication number: 20120099998
    Abstract: An example method of attaching an airfoil for an integrally bladed rotor includes placing a support collar in an installed position around at least a leading edge and trailing edge of an airfoil stub to be repaired in an integrally bladed rotor. The support collar and the airfoil stub together have a midline that is positioned between opposing, laterally outer surfaces of the airfoil stub when the support collar is in the installed position. The method performs linear friction welding to add a replacement airfoil to the airfoil stub.
    Type: Application
    Filed: October 22, 2010
    Publication date: April 26, 2012
    Inventors: James J. Moor, Herbert A. Chin, Greg Czeladko, Gene A. Danko, Andrew L. Haynes, Wangen Lin, Vincent Navins, Robert P. Schaefer, Eberhardt Privitzer
  • Publication number: 20110138624
    Abstract: A method of repairing an integrally bladed rotor includes the steps of placing a support collar around at least a leading and trailing edge portions of the blade stub, and performing linear friction welding to add a replacement airfoil to the blade stub. The linear friction welding is generally along a direction between the leading and trailing edges. In addition, the support collar leading and trailing edge portions are connected together.
    Type: Application
    Filed: December 16, 2009
    Publication date: June 16, 2011
    Inventors: Herbert A. Chin, Robert P. Schaefer, Eberhardt Privitzer, Wangen Lin, Billie W. Bunting, James J. Moor, Vincent Nevins, JR., Andrew L. Haynes, Greg Czeladko, Kenneth T. Raczewski
  • Publication number: 20110138625
    Abstract: A method is provided for repairing a damaged rotor blade on an integrally bladed rotor by removing a damaged portion of a damaged blade leaving a blade stub extending outwardly from the disk and performing a linear friction welding operation to attach a replacement blade segment to the blade stub. The rotor may be disposed operation using a linear friction welding apparatus. The method includes disposing a support collar about the blade stub and securing the support collar to the linear friction welding apparatus prior to a commencement of the bonding operation. A lower surface of the support collar is contoured to mate with a portion of an outer circumference surface of the rotor disk.
    Type: Application
    Filed: March 19, 2010
    Publication date: June 16, 2011
    Applicant: United Technologies Corporation
    Inventors: Herbert A. Chin, Robert P. Schaefer, Eberhardt Privitzer, Wangen Lin, Billie W. Bunting, James J. Moor, Vincent Nevins, Andrew L. Haynes, Greg Czeladko, Kenneth T. Raczewski
  • Patent number: 7244320
    Abstract: Systems and methods for repairing Thermo-Span® gas turbine engine components are described herein. Embodiments of these methods minimize post-weld residual stresses in a weld repaired Thermo-Span® component by solution heat treating the component by heating the component to about 2000° F.±25° F., holding the component at about 2000° F.±25° F. for about one hour; and cooling the component to below about 700° F. at a rate equivalent to cooling in air; and precipitation heat treating the component by heating the component to about 1325° F.±25° F., holding the component at about 1325° F.±25° F. for about 8 hours, cooling the component to about 1150° F.±25° F. at a maximum rate of about 100° F./hour, holding the component at about 1150° F.±25° F. for about 8 hours, and cooling the component at a predetermined cooling rate. Dimensions of the fully-machined and weld repaired component are maintained during solution heat treating and precipitation heat treating via custom designed furnace tools.
    Type: Grant
    Filed: June 1, 2004
    Date of Patent: July 17, 2007
    Assignee: United Technologies Corporation
    Inventors: David R. Malley, Carl E. Kelly, Robert P. Schaefer
  • Patent number: 5806751
    Abstract: A method of repairing a metallic alloy article having a defect cavity greater than about 0.010 inches (2.5.times.10.sup.-4 m) in maximum width is disclosed. One aspect of the invention includes providing a first metallic filler material (10) in the defect cavity such that the first metallic filler material (10) substantially fills the cavity. The composition of the first metallic filler material (10) corresponds substantially to that of the metallic article. A second metallic filler material (12) is provided over the first metallic filler material (10). The second metallic filler material (12) includes between about 0 wt. % and about 40 wt. % metallic filler material of a composition corresponding substantially to the metallic article, and between about 100 wt. % and about 60 wt. % metallic filler material having the same basis as the composition of the metallic alloy article and including a melting point depressant in an amount substantially in excess of that in the metallic alloy article.
    Type: Grant
    Filed: October 17, 1996
    Date of Patent: September 15, 1998
    Assignee: United Technologies Corporation
    Inventors: Robert P. Schaefer, William F. Bender, Matthew J. Arnold
  • Patent number: 4851188
    Abstract: An abrasive, wear resistant layer is applied to the tip surface of a superalloy gas turbine blade by high temperature sintering operation which produces a high strength bond between the layer and the blade, minimizes gamma prime phase growth, and prevents recrystallization in the blade. Important features of the invention include removing plastic strain damage from the tip surface prior to the sintering operation, using induction heating techniques to sinter a layer of metal powder particles and ceramic particulates to the blade tip surface, and shielding the airfoil and root portion of the blade from the radiant heating source during the sintering operation while at the same time, conductively removing heat from the blade.
    Type: Grant
    Filed: December 21, 1987
    Date of Patent: July 25, 1989
    Assignee: United Technologies Corporation
    Inventors: Robert P. Schaefer, Walter F. Gustafson, David A. Rutz, Kenneth E. Taylor
  • Patent number: 4802828
    Abstract: A gas turbine engine blade has an abrasive material tip with a fused superalloy matrix and evenly distributed ceramic particulate. The matrix will have a desirable metallurgical structure characterized by fine dendrites and remanants of the original powder metal structure from which it was made. Due to the fusion of the tip, the peripheral edge will tend to be curved. To lessen the effect of thermal strains on such an abrasive tip, a sheath of a superalloy, such as a portion of the turbine blade substrate, extends along the side of the abrasive. The sheath may be present only in the thicker leading edge part of the blade airfoil.
    Type: Grant
    Filed: December 29, 1986
    Date of Patent: February 7, 1989
    Assignee: United Technologies Corporation
    Inventors: David A. Rutz, Edward Lee, Robert P. Schaefer, Edward L. Johnson
  • Patent number: 4735656
    Abstract: An abrasive material comprised of a metal matrix and evenly distributed ceramic particulates, is made by mixing powder metal with the ceramic powder and heating to a temperature sufficient to melt most, but not all of the powder. In this way the ceramic does not float to the top of the material, yet a dense material is obtained. A nickel superalloy matrix will have at least some remnants of the original powder metal structure, typically some equiaxed grains, along with a fine dendritic structure, thereby imparting desirable high temperature strength when the abrasive material is applied to the tips of blades of gas turbine engines. Preferred matrices have a relatively wide liquidus-solidus temperature range, contain a melting point depressant, and a reactive metal to promote adhesion to the ceramic.
    Type: Grant
    Filed: December 29, 1986
    Date of Patent: April 5, 1988
    Assignee: United Technologies Corporation
    Inventors: Robert P. Schaefer, David A. Rutz, Edward Lee, Edward J. Johnson
  • Patent number: 4073639
    Abstract: In filling voids in or between metallic articles, as in the repair of cracks or other surface defects in castings, the void is filled with a powder mix which upon heat treatment fills the void. The filler powder mix is a blend of at least two distinct powder components and in terms of overall composition preferably corresponds to that of article being repaired. The components comprising the mix are selected to provide a transient liquid phase and isothermal resolidification of a portion of the mix at the temperature below the article melting point. A subsequent heat treatment is preferably utilized for homogenization.
    Type: Grant
    Filed: November 24, 1976
    Date of Patent: February 14, 1978
    Assignee: United Technologies Corporation
    Inventors: David S. Duvall, William A. Owczarski, Daniel F. Paulonis, Robert P. Schaefer
  • Patent number: 4008844
    Abstract: In filling voids in or between metallic articles, as in the repair of cracks or other surface defects in castings, the void is filled with a powder mix which upon heat treatment fills the void. The filler powder mix is a blend of at least two distinct powder components and in terms of overall composition preferably corresponds to that of article being repaired. The components comprising the mix are selected to provide a transient liquid phase and isothermal resolidification of a portion of the mix at the temperature below the article melting point. A subsequent heat treatment is preferably utilized for homogenization.
    Type: Grant
    Filed: January 6, 1975
    Date of Patent: February 22, 1977
    Assignee: United Technologies Corporation
    Inventors: David S. Duvall, William A. Owczarski, Daniel F. Paulonis, Robert P. Schaefer