Patents by Inventor Radovan Kovacevic

Radovan Kovacevic 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).

  • Publication number: 20070275262
    Abstract: A plated substrate comprises a plating layer disposed outwardly from a substrate. The substrate comprises a substrate material, where the substrate material comprises a metal. The plating layer comprises a plating material and blocking particles. The plating material comprises grains, and the blocking particles are disposed within interstices between the grains. The blocking particles are scattered substantially uniformly throughout at least a portion of the plating layer, and contribute to formation of boundaries.
    Type: Application
    Filed: May 23, 2006
    Publication date: November 29, 2007
    Inventors: Dechao Lin, Radovan Kovacevic, Donald C. Price
  • Publication number: 20070241163
    Abstract: An apparatus for welding a workpiece has a welding head and a rotating tool. The welding head has a recessed portion and a welding head end to be placed in contact with a surface of the workpiece. The rotating tool is disposed within the recessed portion of the welding head. The rotating tool is operable to rotate about an axis and to translate along the axis. The rotating tool comprises a rotating tool end to be placed in contact with material of the workpiece. The rotating tool end comprises a shoulder and one or more off-center protrusions. The shoulder has a surface operable to frictionally heat the material of the workpiece. An off-center protrusion is operable to penetrate and displace the material of the workpiece to form a weld.
    Type: Application
    Filed: April 17, 2006
    Publication date: October 18, 2007
    Inventors: Michael Valant, Radovan Kovacevic
  • Patent number: 7045738
    Abstract: A powder delivery system for a laser-based additive manufacturing process includes a hopper adapted to contain a powder and continuously feed the powder through an output of the hopper, a rotatable disk having a top surface that is substantially flat, the top surface adapted to receive the powder continuously fed through the output of the hopper, the top surface being disposed below the output of the hopper by a prescribed gap, and a vacuum powder removal device operable to remove the powder from the top surface via a vacuum.
    Type: Grant
    Filed: August 25, 2003
    Date of Patent: May 16, 2006
    Assignee: Southern Methodist University
    Inventors: Radovan Kovacevic, Michael E. Valant
  • Patent number: 7020539
    Abstract: According to one embodiment of the invention, a system for fabricating a part includes a computer operable to control the fabrication of a three-dimensional part using a solid CAD model, a deposition station operable to deposit successive two-dimensional layers of material to fabricate the three-dimensional part, and a machining station operable to remove at least a portion of one or more of the deposited two-dimensional layers of material. The deposition station includes a substrate on which to fabricate the three-dimensional part, a welding-based deposition system having a welding torch, a laser-based deposition system having a laser head, a plasma powder cladding system having a plasma torch, and a multi-axis robot operable to, when directed by the computer, utilize one of the welding-based deposition system, laser-based deposition system, and plasma powder cladding system to deposit any of the two-dimensional layers of material.
    Type: Grant
    Filed: August 25, 2003
    Date of Patent: March 28, 2006
    Assignee: Southern Methodist University
    Inventors: Radovan Kovacevic, Michael E. Valant
  • Patent number: 6995334
    Abstract: According to one embodiment of the invention, a method for controlling the size of the molten pool in a laser based additive manufacturing process includes coaxially aligning an imaging device with a laser nozzle and imaging a molten pool, created by a laser, on a substrate with the imaging device. The method further includes comparing at least one characteristic of the molten pool with a respective characteristic of a target molten pool, and adjusting, in substantially real-time, a laser power of the laser based on the comparison in order to correlate the characteristic of the molten pool with the respective characteristic of the target molten pool.
    Type: Grant
    Filed: August 25, 2003
    Date of Patent: February 7, 2006
    Assignee: Southern Methodist University
    Inventors: Radovan Kovacevic, Dongming Hu, Michael E. Valant
  • Patent number: 6940037
    Abstract: According to one embodiment of the invention, a method for controlling operational weld parameters of a welding-based deposition process includes generating a solid model representing a three-dimensional part on a computer, electronically slicing the solid model into a plurality of electronic two-dimensional layers, identifying a path of material deposition based on the electronic two-dimensional layers, the path comprising a plurality of deposition points, and determining a geometrical factor for each deposition point. The geometrical factor is defined by a ratio of an actual volume of material around each deposition point to a theoretical volume of material around each deposition point. The method further includes automatically adjusting, during material deposition for a respective deposition point, one or more parameters of the welding-based deposition process based on the geometrical factor for the respective deposition point.
    Type: Grant
    Filed: August 25, 2003
    Date of Patent: September 6, 2005
    Assignee: Southern Methodist University
    Inventors: Radovan Kovacevic, Zoran Jandric, Michael E. Valant, Ivan S. Kmecko
  • Patent number: 6013896
    Abstract: An improved method of gas metal arc welding (GMAW) utilizing relatively low current levels. The method includes providing a variable current to form and detach a droplet from a consumable wire electrode. During the welding process, the current is sufficient to produce a droplet at the end of a consumable electrode wire, but not to independently detach the droplet. After the droplet reaches a desired diameter, the current is lowered to induce an oscillation in the droplet. At a selected oscillation of the droplet, the current is increased. The combination of the momentum created by the oscillation of the droplet and the electromagnetic force caused by the increased current serves to detach the droplet from the electrode wire.
    Type: Grant
    Filed: March 20, 1998
    Date of Patent: January 11, 2000
    Assignee: University of Kentucky Research Foundation
    Inventors: Yuming Zhang, Liguo E, Radovan Kovacevic
  • Patent number: 5481085
    Abstract: A method and apparatus are provided allowing the determination of 3-D weld pool surface geometry in the presence of a welding arc during a welding operation. The method includes the steps of illuminating the weld pool surface with diffused, structured light and detecting specular reflection of that diffused, structured light from the weld pool surface. An acquired image results. By analyzing the acquired image it is possible to determine the geometry of the weld pool surface. The apparatus for performing the method includes a high intensity light source, a diffuser and a structured light forming grid. A camera is provided for specular reflection detection of the light reflecting from the weld pool surface.
    Type: Grant
    Filed: September 9, 1994
    Date of Patent: January 2, 1996
    Assignee: University of Kentucky Research Foundation
    Inventors: Radovan Kovacevic, Yu M. Zhang
  • Patent number: 5288186
    Abstract: An apparatus for high-pressure waterjet assisted machining includes a drive motor, spindle and rotary cutting tool with cutting inserts. The apparatus further includes a high-pressure intensifier pump providing cutting fluid at a pressure greater than 50,000 psi. A cutting fluid conduit system in the rotary cutting tool includes a main flow channel, a distribution manifold, a plurality of radially extending feed channels and a plurality of cooperating nozzles for delivering fluid behind the cutting inserts. The cutting fluid then passes through one or more apertures in the inserts into an interface defined by the inserts of the cutting tool and a chip being cut from the workpiece.
    Type: Grant
    Filed: September 21, 1992
    Date of Patent: February 22, 1994
    Assignee: University of Kentucky Research Foundation
    Inventor: Radovan Kovacevic