Patents by Inventor Pei-Chung Wang

Pei-Chung Wang 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).

  • Sheet-to-tube resistance spot welding using servo gun
    Patent number: 7060929
    Abstract: A method of spot welding a sheet overlapped to a tube with a servomotor-driven electrode applying a clamping force to the sheet. Over a first clamping time interval, the clamping force is increased to a first force level, at which point a welding current is applied to weld the sheet and tube together for a welding time interval. The first force level is maintained for a second clamping time interval, after which the clamping force is reduced to a second force level over a third clamping time interval and is maintained for a fourth clamping time interval. The welding current is removed upon expiration of the welding time interval and the clamping force is simultaneously reduced over a fifth clamping time interval, after which the electrode is disengaged from the sheet. The reduction in clamping force during the welding cycle reduces cracking of the spot weld.
    Type: Grant
    Filed: February 24, 2004
    Date of Patent: June 13, 2006
    Assignee: General Motors Corporation
    Inventors: Peter C. Sun, Pei-Chung Wang
  • Projection weld-bonding system and method
    Patent number: 7053330
    Abstract: A method of welding and a projection weld bond system is disclosed. A first workpiece is provided that is made of a material that conducts electricity, and a second workpeiece is provided that is made of a material that conducts electricity and has a plurality of projections formed therein. A materail is applied between each projections of plurality of projections, the material having electrical conductivity that is lower than the conductivity of the second workpiece. An area of the first workpiece is disposed at the plurality of projections of the second workpiece, and electricity is conducted through the first workpiece and through at least one of the plurality of projections of the second workpiece.
    Type: Grant
    Filed: February 13, 2004
    Date of Patent: May 30, 2006
    Assignee: General Motors Corporation
    Inventors: Pei-Chung Wang, Robin Stevenson
  • Resistance welding tip with improved cooling system
    Publication number: 20060108329
    Abstract: An improved cooling system for adapting to a two-component welding electrode device having a shank and cap, includes a retractable nozzle tube, a manifold, and an adjustment element for adjustably interconnecting the tube and manifold. A threaded bushing or plunger is attached to the tube and operable to adjust the distance between the interior surface of the cap and the outlet of the tube to a preferred distance. A threaded sleeve interconnects the tube and bushing for additional adjustability. The tube defines an elastically compressible bellows section, and a spacer is removably attached to the distal end of the tube for automatic adjustment of the outlet position by the cap.
    Type: Application
    Filed: November 24, 2004
    Publication date: May 25, 2006
    Inventors: Robin Stevenson, Pei-Chung Wang
  • Adhesive encapsulated blind rivet system
    Patent number: 7017255
    Abstract: A blind rivet system including a number of parts to be joined that have aligned holes. A tubular rivet body is disposed in the aligned holes and includes a rivet head portion and a sleeve portion. The head portion and sleeve portion include a longitudinal bore. A mandrel having a head portion greater in diameter than the bore and a shaft portion is disposed within the longitudinal bore. An adhesive is disposed in an annular space defined by the interior surface of the bore and an exterior surface of the shaft portion. An installation tool having a seal intersects with the rivet head portion such that when the head portion is drawn within the bore during installation, the adhesive is maintained within the tubular rivet body and extruded from the annular space to a region between faying surfaces of the parts to be joined.
    Type: Grant
    Filed: April 7, 2003
    Date of Patent: March 28, 2006
    Assignee: General Motors Corporation
    Inventors: Pei-Chung Wang, Robin Stevenson
  • Rivet with sliding cap for friction stir riveting
    Patent number: 7013768
    Abstract: A friction stir rivet is rotated and driven through a first fusible workpiece into an engaged second fusible workpiece, causing local portions of the first and second workpieces to plasticize. A slideable cap contacts the exposed surface of the first workpiece shortly after the process begins. The contact causes the cap to act as a retaining element, limiting the escape of plasticized material from stir site. Once the rivet is driven into the first and second workpieces, rotation ceases and the plasticized material hardens around the rivet. A weld is thus created, joining the workpieces and encompassing the rivet, which provides additional mechanical strength.
    Type: Grant
    Filed: September 28, 2004
    Date of Patent: March 21, 2006
    Assignee: General Motors Corporation
    Inventors: Robin Stevenson, Pei-Chung Wang
  • Programmable resistance seam welding apparatus and method
    Publication number: 20060043074
    Abstract: A resistance welding apparatus having a pair of programmable ball electrodes carried on universally movable positioners. The positioners are programmed to move the ball electrodes simultaneously along a seam line so that the ball electrodes clamp and support opposite sides of a pair of stacked workpieces and are electrically charged to form resistance seam welds along the seam lines to connect the workpieces.
    Type: Application
    Filed: August 24, 2004
    Publication date: March 2, 2006
    Inventors: Peter Sun, Pei-Chung Wang
  • Tubular joint assembly
    Patent number: 7001097
    Abstract: A joint assembly for joining first and second tubular members. The first member has flanges extending from walls of an end segment. The walls of the end segment define a receiving opening. The second member has walls and a protrusion having sides extending from the walls to an end of the protrusion. When the members are joined the protrusion is received in the opening of the end segment so that the sides of the protrusion are in facing engagement with the walls of the end segment and the flanges engage the walls of the second member. The members are secured together at some of the engaging surfaces. The protrusion reduces stress on the flanges and increases the mechanical strength of the assembly.
    Type: Grant
    Filed: April 2, 2003
    Date of Patent: February 21, 2006
    Assignee: General Motors Corporation
    Inventors: Pei-Chung Wang, Peter C. Sun, Kenneth R. Schmidt
  • Programmable non-contact fusion welding apparatus and method
    Publication number: 20060027541
    Abstract: A non-contact fusion welding apparatus has a pair of programmable clamps carried on universally movable positioners. The positioners are programmed to move the clamps sequentially along a laser weld path so that the clamps, engage and support opposite surfaces of the pair of workpieces at respective selected locations during the weld process to insure intimate and continuous contact between the workpieces along the entire length of the laser weld site.
    Type: Application
    Filed: August 3, 2004
    Publication date: February 9, 2006
    Inventors: Peter Sun, Pei-Chung Wang
  • Friction stir rivet and method of joining therewith
    Publication number: 20060024145
    Abstract: A friction stir rivet having a body, a mandrel, and a mechanical interface therebetween, is disclosed. The body has an elongated cylindrical shank, a cap at a first end, and an axial hole therethrough. The mandrel has an elongated shaft defining an axis and a head at one end thereof, the head having an effective outside diameter greater than the effective outside diameter of the shaft, the shaft being disposed within the axial hole of the body, the mandrel head being disposed at an opposite end of the body to that of the cap, and the end of the mandrel head having a flat surface oriented substantially perpendicular to the axis of the shaft. The mechanical interface between the body and the mandrel is such that the body rotates in response to rotation of the mandrel.
    Type: Application
    Filed: November 24, 2004
    Publication date: February 2, 2006
    Inventors: Pei-Chung Wang, Robin Stevenson
  • Friction stir rivet drive system and stir riveting methods
    Patent number: 6988651
    Abstract: Friction stir fastener equipment and method in which a series of friction stir rivets are rotatably mounted in a supply station and a computer controlled arm terminating in a rotating working head having special gripping jaws that precisely locates and grips a selected rivet. The arm then moves the rotating rivet and progressively drives it into the work until a frictionally heated and plasticized zone of material around the shank of the rivet begins to solidify. The jaws then release the rivet from the drive so that the rivet rotation decelerates to zero. Sufficient hardening of the zone effects the completion of one stir riveting cycle which may be automatically repeated.
    Type: Grant
    Filed: February 17, 2004
    Date of Patent: January 24, 2006
    Assignee: General Motors Corporation
    Inventors: Robin Stevenson, Pei-Chung Wang
  • Laser welding control
    Publication number: 20060011592
    Abstract: In laser welding of metallic workpieces, the energetic beam is moved over the workpiece surface to form a pool of molten weld metal that quickly solidifies behind the advance of the laser into a weld nugget. The laser beam produces a keyhole of plasma-containing vapor within the molten pool. Weld nugget porosity, due to entrapment of the vapor, is minimized by continually sensing radiation from the molten metal pool to determine pool depth and width and then controlling laser power and speed to continually produce a weld metal pool wide enough for the liquid to fully expel the vapor and solidify into a pore free nugget.
    Type: Application
    Filed: July 14, 2004
    Publication date: January 19, 2006
    Inventors: Pei-Chung Wang, Hai-Lung Tsai, Yueh-Se Huang, Phillip Turner
  • Resistance welding of high strength steels
    Publication number: 20050247679
    Abstract: The formation of spot welds in high strength steel workpieces is improved by using welding electrodes with annular, or donut shaped welding tips for the formation of the molten metal weld pool at the weld site. The annular poll solidifies to form an annular weld nugget. Preferably the donut shaped nugget has an internal diameter that is no more than three-quarters of the outside diameter. The method is applicable to carbon steel workpieces with allowing elements for strengthening, and to thick sheets of mild carbon steels.
    Type: Application
    Filed: May 10, 2004
    Publication date: November 10, 2005
    Inventor: Pei-Chung Wang
  • Method of metallurgically bonding articles and article therefor
    Publication number: 20050247687
    Abstract: An article suitable for arc-welded metallurgical bonding having a first part having a lower surface, and a second part having an upper surface is disclosed. The lower surface of the first part is disposed at the upper surface of the second part to provide for a faying surface thereat. The faying surface has a plurality of channels with a depth equal to or greater than about 1 micron and equal to or less than about 1000 microns. The article is suitable for arc-welded metallurgical bonding at the faying surface. The plurality of channels has a repetitive pattern of channels arranged along a path of the faying surface in a direction of the metallurgical bonding action.
    Type: Application
    Filed: May 4, 2004
    Publication date: November 10, 2005
    Inventors: Pei-Chung Wang, Hai-Lung Tsai, Louis Hector
  • Method of metallurgically bonding articles and article therefor
    Publication number: 20050247678
    Abstract: An article suitable for metallurgical bonding having a first part having a lower surface, and a second part having an upper surface is disclosed. The lower surface of the first part is disposed at the upper surface of the second part to provide for a faying surface thereat. The faying surface has a plurality of channels having a depth equal to or greater than about 1 micron and equal to or less than about 1000 microns. The article is suitable for metallurgical bonding at the faying surface.
    Type: Application
    Filed: May 4, 2004
    Publication date: November 10, 2005
    Inventors: Pei-Chung Wang, Hai-Lung Tsai
  • Adhesive dispersing rivet
    Patent number: 6962469
    Abstract: A rivet and method for riveting metal members, and particularly, metal sheets is disclosed. The apparatus includes a rivet assembly for driving a piercing rivet into stacked metal sheets and a die for assisting in supporting the sheets during driving of the rivet and for assisting in securing the rivets to the sheets. The rivet of the invention includes an adhesive that is forced through passages in the rivet for assisting in fastening the rivet to the sheets and for assisting in fastening the sheets to each other with greater strength.
    Type: Grant
    Filed: March 11, 2004
    Date of Patent: November 8, 2005
    Assignee: General Motors Corporation
    Inventors: Pei-Chung Wang, Daniel B. Hayden, Robin Stevenson
  • Compound laser beam welding
    Publication number: 20050230364
    Abstract: Hot cracking in laser welds produced in metal workpieces, especially aluminum or magnesium sheet alloys, is avoided by suitably combining the beams of two different lasers, for example a CO2 laser and a YAG laser, into a compound beam that is moved along a weld path in the surface of the workpiece. The power level of at least one of the lasers is cyclically varied so that weld nugget segments of different alternating, hot crack free, configurations are produced in a linear weld.
    Type: Application
    Filed: April 20, 2004
    Publication date: October 20, 2005
    Inventors: Pei-Chung Wang, Shigeki Saitoh, Fujiko Matsuda, Masami Takeshi, Masatake Saito
  • Sheet metal assembly and method to reduce weight
    Publication number: 20050230361
    Abstract: A sheet metal assembly includes first and second resistance weldable metal sheets having flanges extending from the sheets. The flanges overlap in parallel for a dimension. A resistance weldable metal shim is disposed between the flanges and extends to the outer edges thereof. A weld joins the metal sheets through the shim. The shim increases the mechanical strength of the assembly. The increase in mechanical strength from the shim allows for reductions to the flange width. As a result, a lighter assembly of equivalent strength is produced.
    Type: Application
    Filed: June 14, 2005
    Publication date: October 20, 2005
    Inventors: Pei-Chung Wang, Joseph Speranza
  • Metal transfer in arc welding
    Publication number: 20050211747
    Abstract: A double pulse welding current method is disclosed for the generation and transfer of droplets of welding metal from an electrode wire to a workpiece in an arc welding process. A suitable background direct current level is specified to deliver a desired number of droplets to the weld site. During each cycle of droplet formation and transfer, a first increased current pulse is applied to the electrode and arc to generate a droplet on the tip of and electrode and then a second further increased current pulse is applied to timely separate the droplet from the electrode for transport in the arc to the workpiece. This double-pulse current application reliably produces one droplet per cycle of pulses to deliver a specified number of droplets to the weld site for improved weld quality and reduced spatter or waste of weld metal.
    Type: Application
    Filed: March 23, 2004
    Publication date: September 29, 2005
    Inventors: Pei-Chung Wang, Hai-Lung Tsai
  • Supplying shielding gas
    Publication number: 20050205647
    Abstract: A flexible articulate tubular device has a shank, a plurality of pivot rings, and a terminus with heat sensors and a fiber optic device. The flexible articulate tubular device is initially positioned, either manually or automatically, near a target weld path with the aid of the fiber optic device. The flexible articulate tubular device is then more precisely articulated to direct the terminus along the target weld path, with the aid of the heat sensors. As such, the flexible articulate tubular device operates in a heat seeking manner to follow the weld bead. Ultimately, a gaseous flux is supplied along the flexible articulate tubular device and toward the target weld path, so as to blast the weld bead with an anti-oxidation shield gas and thereby protect the weld.
    Type: Application
    Filed: March 18, 2004
    Publication date: September 22, 2005
    Inventors: Pei-Chung Wang, Toshinori Sakai
  • Sheet-to-tube resistance spot welding using servo gun
    Publication number: 20050184031
    Abstract: A method of spot welding a sheet overlapped to a tube with a servomotor-driven electrode applying a clamping force to the sheet. Over a first clamping time interval, the clamping force is increased to a first force level, at which point a welding current is applied to weld the sheet and tube together for a welding time interval. The first force level is maintained for a second clamping time interval, after which the clamping force is reduced to a second force level over a third clamping time interval and is maintained for a fourth clamping time interval. The welding current is removed upon expiration of the welding time interval and the clamping force is simultaneously reduced over a fifth clamping time interval, after which the electrode is disengaged from the sheet. The reduction in clamping force during the welding cycle reduces cracking of the spot weld.
    Type: Application
    Filed: February 24, 2004
    Publication date: August 25, 2005
    Inventors: Peter Sun, Pei-Chung Wang