Patents by Inventor H. Ravindranath Shetty

H. Ravindranath Shetty 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: 9656358
    Abstract: A method for attaching a porous metal layer to a dense metal substrate, wherein the method is particularly useful in forming orthopedic implants such as femoral knee components, femoral hip components, and/or acetabular cups. The method, in one embodiment thereof, comprises providing a solid metal substrate; providing a porous metal structure; contouring a surface of the porous metal structure; placing the porous structure against the substrate such that the contoured surface of the porous metal structure is disposed against the substrate, thereby forming an assembly; applying heat and pressure to the assembly in conjunction with thermal expansion of the substrate in order to metallurgically bond the porous structure and the substrate; and removing mass from the substrate after the porous structure is bonded to the substrate, thereby finish processing the assembly.
    Type: Grant
    Filed: April 15, 2013
    Date of Patent: May 23, 2017
    Assignee: Zimmer, Inc.
    Inventors: Steven Charlebois, Leslie N. Gilbertson, Michael E Hawkins, Dana Medlin, H. Ravindranath Shetty, Steven Zawadzki
  • Patent number: 8985430
    Abstract: A method for attaching a porous metal layer to a dense metal substrate, wherein the method is particularly useful in forming orthopedic implants such as femoral knee components, femoral hip components, and/or acetabular cups. The method, in one embodiment thereof, comprises providing a solid metal substrate; providing a porous metal structure; contouring a surface of the porous metal structure; placing the porous structure against the substrate such that the contoured surface of the porous metal structure is disposed against the substrate, thereby forming an assembly; applying heat and pressure to the assembly in conjunction with thermal expansion of the substrate in order to metallurgically bond the porous structure and the substrate; and removing mass from the substrate after the porous structure is bonded to the substrate, thereby finish processing the assembly.
    Type: Grant
    Filed: May 1, 2012
    Date of Patent: March 24, 2015
    Assignee: Zimmer, Inc.
    Inventors: Steven J. Charlebois, Leslie N. Gilbertson, Michael E. Hawkins, Dana J. Medlin, H. Ravindranath Shetty, Steven A. Zawadzki
  • Publication number: 20120234461
    Abstract: A method for attaching a porous metal layer to a dense metal substrate, wherein the method is particularly useful in forming orthopedic implants such as femoral knee components, femoral hip components, and/or acetabular cups. The method, in one embodiment thereof, comprises providing a solid metal substrate; providing a porous metal structure; contouring a surface of the porous metal structure; placing the porous structure against the substrate such that the contoured surface of the porous metal structure is disposed against the substrate, thereby forming an assembly; applying heat and pressure to the assembly in conjunction with thermal expansion of the substrate in order to metallurgically bond the porous structure and the substrate; and removing mass from the substrate after the porous structure is bonded to the substrate, thereby finish processing the assembly.
    Type: Application
    Filed: May 1, 2012
    Publication date: September 20, 2012
    Applicant: ZIMMER TECHNOLOGY, INC.
    Inventors: Steven J. Charlebois, Leslie N. Gilbertson, Michael E. Hawkins, Dana J. Medlin, H. Ravindranath Shetty, Steven A. Zawadzki
  • Patent number: 8191760
    Abstract: A method for attaching a porous metal layer to a dense metal substrate, wherein the method is particularly useful in forming orthopedic implants such as femoral knee components, femoral hip components, and/or acetabular cups. The method, in one embodiment thereof, comprises providing a solid metal substrate; providing a porous metal structure; contouring a surface of the porous metal structure; placing the porous structure against the substrate such that the contoured surface of the porous metal structure is disposed against the substrate, thereby forming an assembly; applying heat and pressure to the assembly in conjunction with thermal expansion of the substrate in order to metallurgically bond the porous structure and the substrate; and removing mass from the substrate after the porous structure is bonded to the substrate, thereby finish processing the assembly.
    Type: Grant
    Filed: February 15, 2011
    Date of Patent: June 5, 2012
    Assignee: Zimmer Technology, Inc.
    Inventors: Steven J. Charlebois, Leslie N. Gilbertson, Michael E. Hawkins, Dana J. Medlin, H. Ravindranath Shetty, Steven A. Zawadzki
  • Publication number: 20110132974
    Abstract: A method for attaching a porous metal layer to a dense metal substrate, wherein the method is particularly useful in forming orthopedic implants such as femoral knee components, femoral hip components, and/or acetabular cups. The method, in one embodiment thereof, comprises providing a solid metal substrate; providing a porous metal structure; contouring a surface of the porous metal structure; placing the porous structure against the substrate such that the contoured surface of the porous metal structure is disposed against the substrate, thereby forming an assembly; applying heat and pressure to the assembly in conjunction with thermal expansion of the substrate in order to metallurgically bond the porous structure and the substrate; and removing mass from the substrate after the porous structure is bonded to the substrate, thereby finish processing the assembly.
    Type: Application
    Filed: February 15, 2011
    Publication date: June 9, 2011
    Applicant: ZIMMER, INC.
    Inventors: Steven J. Charlebois, Leslie N. Gilbertson, Michael E. Hawkins, Dana J. Medlin, H. Ravindranath Shetty, Steven A. Zawadzki
  • Patent number: 7918382
    Abstract: A method for attaching a porous metal layer to a dense metal substrate, wherein the method is particularly useful in forming orthopedic implants such as femoral knee components, femoral hip components, and/or acetabular cups. The method, in one embodiment thereof, comprises providing a solid metal substrate; providing a porous metal structure; contouring a surface of the porous metal structure; placing the porous structure against the substrate such that the contoured surface of the porous metal structure is disposed against the substrate, thereby forming an assembly; applying heat and pressure to the assembly in conjunction with thermal expansion of the substrate in order to metallurgically bond the porous structure and the substrate; and removing mass from the substrate after the porous structure is bonded to the substrate, thereby finish processing the assembly.
    Type: Grant
    Filed: April 18, 2005
    Date of Patent: April 5, 2011
    Assignee: Zimmer Technology, Inc.
    Inventors: Steven J. Charlebois, Leslie N. Gilbertson, Michael E. Hawkins, Dana J. Medlin, H. Ravindranath Shetty, Steven A. Zawadzki
  • Patent number: 7790216
    Abstract: A method for producing a zirconia-layered orthopedic implant component includes depositing zirconium onto the orthopedic implant component, thereby forming a zirconium-layered component, and converting at least a portion of the zirconium into a substantially monoclinic zirconia surface layer unaccompanied by a substantial underlying ?-phase. A method for producing a zirconia-layered orthopedic implant component includes depositing zirconium onto the orthopedic implant component by ion bombardment and deposition in a vacuum to form a zirconium-layered component including an intermix zone at least 1000 ? thick and a zirconium layer about 3-5 ?m thick, and heat treating the zirconium-layered component at a temperature of about 500-600° C. in an atmosphere containing oxygen.
    Type: Grant
    Filed: April 19, 2005
    Date of Patent: September 7, 2010
    Assignee: Zimmer Technology, Inc.
    Inventors: Oludele Popoola, Jeffrey P. Anderson, Michael E. Hawkins, Todd S. Johnson, H. Ravindranath Shetty
  • Patent number: 6945448
    Abstract: A method for attaching a porous metal layer to a dense metal substrate, wherein the method is particularly useful in forming orthopedic implants such as femoral knee components or acetabular cups. The method, in one embodiment thereof, comprises providing a structured porous layer; providing a dense metal substrate; providing a binding mixture; applying the binding mixture to the exterior of the substrate; placing the porous layer against the substrate such that the binding mixture is disposed there between forming an assembly; and heat treating the assembly to metallurgically bond the porous layer to the substrate.
    Type: Grant
    Filed: June 6, 2003
    Date of Patent: September 20, 2005
    Assignee: Zimmer Technology, Inc.
    Inventors: Dana J. Medlin, Steven J. Charlebois, William Clarke, Dirk L. Pletcher, Joel G. Scrafton, H. Ravindranath Shetty, Dale Swarts
  • Publication number: 20040133283
    Abstract: A method for producing an orthopaedic implant having enhanced fatigue strength. A forged implant substrate having an elongated stem is incorporated with a melting point lowering substance. Then, metal particles are sintered to the substrate, forming a porous layer on the substrate which enhances bone ingrowth or the mechanical interlock with bone cement. Advantageously, the sintering occurs at a lower temperature than if the substance were not incorporated into the substrate, which in turn results in an enhanced fatigue strength of the inventive implant. The fatigue strength of a forged or cast implant can also be improved by nitrogen diffusion hardening and/or thermally processing the implant after the porous coating is adhered by sintering. Further, the fatigue strength can be further improved by combining incorporating the melting point lowering substance with nitrogen diffusion hardening and/or aging treatment subsequent to sintering.
    Type: Application
    Filed: December 17, 2003
    Publication date: July 8, 2004
    Inventor: H. Ravindranath Shetty
  • Patent number: 6685987
    Abstract: A method for producing an orthopaedic implant having enhanced fatigue strength. A forged implant substrate having an elongated stem is incorporated with a melting point lowering substance. Then, metal particles are sintered to the substrate, forming a porous layer on the substrate which enhances bone in growth or the mechanical interlock with bone cement. Advantageously, the sintering occurs at a lower temperature than if the substance were not incorporated into the substrate, which in turn results in an enhanced fatigue strength of the inventive implant. The fatigue strength of a forged or cast implant can also be improved by nitrogen diffusion hardening and/or thermally processing the implant after the porous coating is adhered by sintering. Further, the fatigue strength can be further improved by combining incorporating the melting point lowering substance with nitrogen diffusion hardening and/or aging treatment subsequent to sintering.
    Type: Grant
    Filed: January 30, 2002
    Date of Patent: February 3, 2004
    Assignee: Zimmer Technology, Inc.
    Inventor: H. Ravindranath Shetty
  • Publication number: 20030232124
    Abstract: A method for attaching a porous metal layer to a dense metal substrate, wherein the method is particularly useful in forming orthopedic implants such as femoral knee components or acetabular cups. The method, in one embodiment thereof, comprises providing a structured porous layer; providing a dense metal substrate; providing a binding mixture; applying the binding mixture to the exterior of the substrate; placing the porous layer against the substrate such that the binding mixture is disposed there between forming an assembly; and heat treating the assembly to metallurgically bond the porous layer to the substrate.
    Type: Application
    Filed: June 6, 2003
    Publication date: December 18, 2003
    Inventors: Dana J. Medlin, Steven J. Charlebois, William Clarke, Dirk L. Pletcher, Joel G. Scrafton, H. Ravindranath Shetty, Dale Swarts
  • Patent number: 6576014
    Abstract: A method for producing an orthopedic implant having enhanced fatigue strength. A forged implant substrate having an elongated stem is incorporated with a melting point lowering substance. Then, metal particles are sintered to the substrate, forming a porous layer on the substrate which enhances bone ingrowth or the mechanical interlock with bone cement. Advantageously, the sintering occurs at a lower temperature than if the substance were not incorporated into the substrate, which in turn results in an enhanced fatigue strength of the inventive implant. The fatigue strength of a forged or cast implant can also be improved by nitrogen diffusion hardening and/or thermally processing the implant after the porous coating is adhered by sintering. Further, the fatigue strength can be further improved by combining incorporating the melting point lowering substance with nitrogen diffusion hardening and/or aging treatment subsequent to sintering.
    Type: Grant
    Filed: April 3, 2002
    Date of Patent: June 10, 2003
    Assignee: Zimmer, Inc.
    Inventor: H. Ravindranath Shetty
  • Publication number: 20020151983
    Abstract: A method for producing an orthopedic implant having enhanced fatigue strength. A forged implant substrate having an elongated stem is incorporated with a melting point lowering substance. Then, metal particles are sintered to the substrate, forming a porous layer on the substrate which enhances bone ingrowth or the mechanical interlock with bone cement. Advantageously, the sintering occurs at a lower temperature than if the substance were not incorporated into the substrate, which in turn results in an enhanced fatigue strength of the inventive implant. The fatigue strength of a forged or cast implant can also be improved by nitrogen diffusion hardening and/or thermally processing the implant after the porous coating is adhered by sintering. Further, the fatigue strength can be further improved by combining incorporating the melting point lowering substance with nitrogen diffusion hardening and/or aging treatment subsequent to sintering.
    Type: Application
    Filed: April 3, 2002
    Publication date: October 17, 2002
    Inventor: H. Ravindranath Shetty
  • Publication number: 20020127328
    Abstract: A method for producing an orthopaedic implant having enhanced fatigue strength. A forged implant substrate having an elongated stem is incorporated with a melting point lowering substance. Then, metal particles are sintered to the substrate, forming a porous layer on the substrate which enhances bone ingrowth or the mechanical interlock with bone cement. Advantageously, the sintering occurs at a lower temperature than if the substance were not incorporated into the substrate, which in turn results in an enhanced fatigue strength of the inventive implant. The fatigue strength of a forged or cast implant can also be improved by nitrogen diffusion hardening and/or thermally processing the implant after the porous coating is adhered by sintering. Further, the fatigue strength can be further improved by combining incorporating the melting point lowering substance with nitrogen diffusion hardening and/or aging treatment subsequent to sintering.
    Type: Application
    Filed: January 30, 2002
    Publication date: September 12, 2002
    Inventor: H. Ravindranath Shetty
  • Patent number: 6395327
    Abstract: A method for producing an orthopaedic implant having enhanced fatigue strength. A forged implant substrate having an elongated stem is incorporated with a melting point lowering substance. Then, metal particles are sintered to the substrate, forming a porous layer on the substrate which enhances bone ingrowth or the mechanical interlock with bone cement. Advantageously, the sintering occurs at a lower temperature than if the substance were not incorporated into the substrate, which in turn results in an enhanced fatigue strength of the inventive implant. The fatigue strength of a forged or cast implant can also be improved by nitrogen diffusion hardening and/or thermally processing the implant after the porous coating is adhered by sintering. Further, the fatigue strength can be further improved by combining incorporating the melting point lowering substance with nitrogen diffusion hardening and/or aging treatment subsequent to sintering.
    Type: Grant
    Filed: March 12, 1999
    Date of Patent: May 28, 2002
    Assignee: Zimmer, Inc.
    Inventor: H. Ravindranath Shetty
  • Patent number: 5926685
    Abstract: The invention is directed to a method of forming an implant having a porous surface using an organic binder compound to enhance the bonding between the porous surface layer and implant. Preferably, the binder is formed from a water-soluble protein that carbonizes during the sintering process to alloy with the metal of the porous surface layer. The porous surface layer may be in the form of beads or of fiber metal and can be preformed to fit with an implant or formed over the surface of the implant.
    Type: Grant
    Filed: January 14, 1998
    Date of Patent: July 20, 1999
    Assignee: Zimmer, Inc.
    Inventors: Steve Krebs, Clarence Panchison, H. Ravindranath Shetty
  • Patent number: 5734959
    Abstract: The invention is directed to a method of forming an implant having a porous surface using an organic binder compound to enhance the bonding between the porous surface layer and implant. Preferably, the binder is formed from a water-soluble protein that carbonizes during the sintering process to alloy with the metal of the porous surface layer. The porous surface layer may be in the form of beads or of fiber metal and can be preformed to fit with an implant or formed over the surface of the implant.
    Type: Grant
    Filed: October 12, 1995
    Date of Patent: March 31, 1998
    Assignee: Zimmer, Inc.
    Inventors: Steve Krebs, Clarence Panchison, H. Ravindranath Shetty
  • Patent number: 5443510
    Abstract: The method forms a thin layer of metal mesh on the surface of the implant for the bonding with a porous surface layer to prevent the formation of notches within the body of the implant. The layer of metal mesh can be formed by a number of known methods including conventional welding processes such as arc welding, resistance welding, electron beam welding, laser beam welding, friction welding, ultrasonic welding, cladding. The porous metal surface layer is preferably formed from titanium wire or titanium beads in a known process. The porous surface layer is bonded by a known process such as diffusion bonding, sintering, welding, or cladding.By bonding the porous surface layer to the thin layer of metal mesh, notches normally formed in the body of the implant are substantially eliminated. Therefore, the designer of the implant is not limited as to the location and amount of porous surface layer to be placed on the implants.
    Type: Grant
    Filed: April 6, 1993
    Date of Patent: August 22, 1995
    Assignee: Zimmer, Inc.
    Inventors: H. Ravindranath Shetty, Clarence M. Panchison
  • Patent number: 5326362
    Abstract: A method of surface hardening titanium orthopedic implant devices, and a titanium orthopedic implant device prepared by the disclosed method. An orthopedic implant device made of pure titanium or a titanium alloy, such as Ti-6Al-4V (ELI) is exposed to molecular nitrogen gas at a process temperature and for a process time duration sufficient to enhance surface hardness and wear resistance properties, without the formation of a measurable TiN layer that tends to increase surface roughness and diminish wear resistance properties. The process temperature is in the range of 750.degree. F. to 1300.degree. F., preferably about 1100.degree. F. and the process time duration at the preferred process temperature is approximately 8 hours. The hardened surface of the titanium implant occurs primarily due to solid solution hardening of the titanium with nitrogen by dissolution.
    Type: Grant
    Filed: February 2, 1993
    Date of Patent: July 5, 1994
    Assignee: Zimmer, Inc.
    Inventors: H. Ravindranath Shetty, Walter H. Ottersberg, Jack E. Parr, Roy D. Crowninshield
  • Patent number: 5323954
    Abstract: A femoral component of a knee prosthesis, including a cobalt-based alloy substrate and a titanium fiber metal pad bonded thereto by means of an interlayer of a cobalt-based alloy including nickel. More specifically, a method of bonding a titanium porous surface to a cobalt-based alloy in an orthopaedic implant device, by first applying an interlayer of a cobalt-based alloy including nickel to the substrate and then bonding a porous structure to the interlayer. In one embodiment, an interlayer of L-605 is first applied to a substrate of Co--Cr--Mo by diffusion bonding at approximately 2200.degree. F. and then a fiber metal pad of CP-titanium is diffusion bonded to the interlayer at approximately 1650.degree. F. A layer of CP-titanium may optionally be placed intermediate the fiber metal pad and interlayer before the second diffusion step. In an alternative embodiment, MP-35N alloy may be substituted for the L-605 alloy.
    Type: Grant
    Filed: November 30, 1992
    Date of Patent: June 28, 1994
    Assignee: Zimmer, Inc.
    Inventors: H. Ravindranath Shetty, Mark A. Heldreth, Jack E. Parr