Patents by Inventor Kalyan K. Maitra

Kalyan K. Maitra 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: 5855674
    Abstract: A method and apparatus for continuous galvanizing of a linear element wherein controlled flow of molten zinc onto the linear element is effected through one or more nozzles, whereby galvanizing may be accomplished without immersion of the linear element in molten zinc. In a preferred embodiment, the apparatus of the invention comprises an annular nozzle having a central opening through which the linear element is axially advanced. The nozzle is configured to provide a converging, generally frustoconical curtain of molten zinc flowing continuously onto the exterior surface of the linear element.
    Type: Grant
    Filed: February 29, 1996
    Date of Patent: January 5, 1999
    Assignee: Allied Tube & Conduit Corporation
    Inventors: Kalyan K. Maitra, Daniel G. McInerney, Carl H. Unger
  • Patent number: 5718765
    Abstract: This continuous galvanizing method and apparatus passes a linear element to be galvanized, e.g., wire, rod, or tube, through a surrounding, relatively short length of conduit which is attached as a cross-tee to the end of a delivery pipe rising from a centrifugal pump submerged in a vat of molten zinc, and continuously flooded with liquid zinc to coat the linear element. The zinc flowing from the open ends of the conduit, and falling as excess from the element being coated, drops back into the vat for recirculation. The vat is covered to provide a substantially closed operating space above the pool of molten zinc to enable the coating to take place in an inert atmosphere.
    Type: Grant
    Filed: February 29, 1996
    Date of Patent: February 17, 1998
    Assignee: Allied Tube & Conduit Corporation
    Inventors: Carl H. Unger, Kalyan K. Maitra
  • Patent number: 5538556
    Abstract: A method and apparatus for continuous galvanizing of a linear element wherein controlled flow of molten zinc onto the linear element is effected through one or more nozzles, whereby galvanizing may be accomplished without immersion of the linear element in molten zinc. In a preferred embodiment, the apparatus of the invention comprises an annular nozzle having a central opening through which the linear element is axially advanced. The nozzle is configured to provide a converging, generally frustoconical curtain of molten zinc flowing continuously onto the exterior surface of the linear element.
    Type: Grant
    Filed: March 28, 1995
    Date of Patent: July 23, 1996
    Assignee: Allied Tube & Conduit Corporation
    Inventors: Kalyan K. Maitra, Daniel G. McInerney, Carl H. Unger
  • Patent number: 5527563
    Abstract: This continuous galvanizing method and apparatus passes a linear element to be galvanized, e.g., wire, rod, or tube, through a surrounding, relatively short length of conduit which is attached as a cross-tee to the end of a delivery pipe rising from a centrifugal pump submerged in a vat of molten zinc, and continuously flooded with liquid zinc to coat the linear element. The zinc flowing from the open ends of the conduit, and falling as excess from the element being coated, drops back into the vat for recirculation. The vat is covered to provide a substantially closed operating space above the pool of molten zinc to enable the coating to take place in an inert atmosphere.
    Type: Grant
    Filed: December 28, 1994
    Date of Patent: June 18, 1996
    Assignee: Allied Tube & Conduit Corporation
    Inventors: Carl H. Unger, Kalyan K. Maitra
  • Patent number: 5506002
    Abstract: A method of galvanizing ferrous linear elements, e.g., tube, pipe, structural shapes, as part of a continuous manufacturing line by passing the axially travelling preheated element through transversely flowing molten zinc.
    Type: Grant
    Filed: May 1, 1995
    Date of Patent: April 9, 1996
    Assignee: Allied Tube & Conduit Corporation
    Inventors: Kalyan K. Maitra, Carl H. Unger
  • Patent number: 5496588
    Abstract: A method and apparatus for continuous galvanizing of a linear element wherein controlled flow of molten zinc onto the linear element is effected through one or more nozzles, whereby galvanizing may be accomplished without immersion of the linear element in molten zinc. In a preferred embodiment, the apparatus of the invention comprises an annular nozzle having a central opening through which the linear element is axially advanced. The nozzle is configured to provide a converging, generally frustoconical curtain of molten zinc flowing continuously onto the exterior surface of the linear element.
    Type: Grant
    Filed: November 14, 1994
    Date of Patent: March 5, 1996
    Assignee: Allied Tube & Conduit Corp.
    Inventors: Kalyan K. Maitra, Daniel G. McInerney, Carl H. Unger
  • Patent number: 5364661
    Abstract: A method and apparatus for continuous galvanizing of a linear element wherein controlled flow of molten zinc onto the linear element is effected through one or more nozzles, whereby galvanizing may be accomplished without immersion of the linear element in molten zinc. In a preferred embodiment, the apparatus of the invention comprises an annular nozzle having a central opening through which the linear element is axially advanced. The nozzle is configured to provide a converging, generally frustoconical curtain of molten zinc flowing continuously onto the exterior surface of the linear element.
    Type: Grant
    Filed: March 4, 1993
    Date of Patent: November 15, 1994
    Assignee: Allied Tube & Conduit Corporation
    Inventors: Kalyan K. Maitra, Daniel G. McInerney, Carl H. Unger
  • Patent number: 5113557
    Abstract: An improved method of manufacturing galvanized steel tubing from steel strip having at least one galvanized surface, which surface becomes the exterior surface of the tubing is provided. In the method of the invention, after the steel strip is roll-formed and welded to complete the tubing and the welded seam is scarfed to remove irregularities, a quantity of an acid solution is applied to substantially only the scarfed area to react with oxidized metal, and the rinsed, leaving the non-scarfed galvanized exterior surface intact. The tubing is then heated to a temperature sufficient to cause the galvanized coating of the exterior surface to begin to flow and the tubing is regalvanized to produce an improved galvanized exterior surface, which is resistant to cracking along the scarfed area.
    Type: Grant
    Filed: March 19, 1991
    Date of Patent: May 19, 1992
    Assignee: Allied Tube & Conduit Corporation
    Inventors: Kalyan K. Maitra, Vijay B. Patel
  • Patent number: 5035042
    Abstract: An improved method of manufacturing galvanized steel tubing from steel strip having at least one galvanized surface, which surface becomes the exterior surface of the tubing is provided. In the method of the invention, after the steel strip is roll-formed and welded to complete the tubing and the welded seam is scarfed to remove irregularities, a quantity of an acid solution is applied to substantially only the scarfed area to react with oxidized metal, and then rinsed, leaving the non-scarfed galvanized exterior surface intact. The tubing is then heated to a temperature sufficient to cause the galvanized coating of the exterior surface to begin to flow and the tubing is regalvanized to produce an improved galvanized exterior surface, which is resistant to cracking along the scarfed area.
    Type: Grant
    Filed: November 17, 1989
    Date of Patent: July 30, 1991
    Assignee: Allied Tube & Conduit Corporation
    Inventors: Kalyan K. Maitra, Vijay B. Patel