Patents by Inventor Min H. Tsai

Min H. Tsai 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: 5394980
    Abstract: A multicompartment mixing capsule which is particularly useful for storage and subsequent intermixing of mercury and silver or a silver alloy to form a dental amalgam material. The amalgam components are contained in separate capsule chambers which are insulated by a diaphragm having a thin frangible perimeter, and a thickened and strengthened center portion. A pestle in one of the chambers impacts the diaphragm during initial capsule shaking in an amalgamator to rupture the frangible diaphragm perimeter, and thereby to permit complete and unimpeded intermixing of the amalgam components.
    Type: Grant
    Filed: December 23, 1993
    Date of Patent: March 7, 1995
    Inventor: Min H. Tsai
  • Patent number: 4626209
    Abstract: An orthodontic bracket containing a thin metallic coating on the bracket base; the coating being applied onto the bracket base by thermally spraying a molten metallic powder.
    Type: Grant
    Filed: April 17, 1984
    Date of Patent: December 2, 1986
    Assignee: Unitek Corporation
    Inventors: Min H. Tsai, John E. Sargeant
  • Patent number: 4544353
    Abstract: An orthodontic direct bond appliance has a body with a base. The base includes a rim extending from its periphery at an angle between about 90.degree. and 170.degree. so as to define a recess for receipt of bonding material. The rim shears off any excess flash.
    Type: Grant
    Filed: October 12, 1982
    Date of Patent: October 1, 1985
    Assignee: Unitek Corporation
    Inventors: Robert S. Maurer, Min H. Tsai
  • Patent number: 4336290
    Abstract: A semi-precious alloy for use in a dental restoration which does not discolor porcelain and remains ductile after firing of a porcelain jacket thereon. The alloy is 80-90% palladium, 5-15% indium, 1-5% gallium, 0.1-0.5% aluminum, 0.1-0.5% silicon, and 0.01-1.0% of at least one element from ruthenium and osmium.
    Type: Grant
    Filed: April 13, 1981
    Date of Patent: June 22, 1982
    Assignee: Unitek Corporation
    Inventor: Min H. Tsai
  • Patent number: 4210447
    Abstract: A method and material for making dental restorations by using a porcelain-covered body of a non-precious metal alloy. The alloy preferably includes about 58-68% nickel, 18-23% chromium, 6-10% molybdenum, up to 5% of at least one rare-earth element, up to 4% columbium plus tantalum, up to 2% iron, and lesser quantities of carbon, aluminum, titanium, silicon and manganese. The alloy is resistant to corrosion by mouth fluids, is easy to finish and polish, and is closely matched to the thermal-expansion properties of commercially available dental porcelains. The alloy does not contaminate alloy-melting crucibles, exhibits excellent bonding characteristics to dental porcelains, is easy to melt and cast, and has sufficient ductility to enable margin burnishing of dental-restoration castings of the alloy.
    Type: Grant
    Filed: November 20, 1978
    Date of Patent: July 1, 1980
    Assignee: Unitek Corporation
    Inventor: Min H. Tsai
  • Patent number: 4194907
    Abstract: A gold alloy for use in a dental restoration which does not cause discoloration and greening of dental porcelain after being cast and having a porcelain jacket fired thereon. The gold alloy also produces extremely clean castings. The alloy is 30-50% gold, 30-50% palladium, 5-30% silver, 0.01-5% of at least one element from silicon, boron, germanium and mixtures thereof and 0.01-1.0% of ruthenium. Other elements are included for strength.
    Type: Grant
    Filed: October 20, 1978
    Date of Patent: March 25, 1980
    Assignee: Unitek Corporation
    Inventor: Min H. Tsai
  • Patent number: 4132830
    Abstract: A gold alloy for use in a dental restoration, and which maintains a true yellow-gold color after being cast and having a porcelain jacket fired thereon. The alloy is 83-87% gold, 7-12% platinum, 1.5-3.0% rhodium, and less than 1.0% copper. Other elements are included for grain refining, strength, formation of bonding oxide for the ceramic jacket, and the like.
    Type: Grant
    Filed: December 27, 1977
    Date of Patent: January 2, 1979
    Assignee: Unitek Corporation
    Inventor: Min H. Tsai