Patents by Inventor David J. Twichell

David J. Twichell 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: 5076557
    Abstract: A gasket and method for detecting the status of an installed gasket is disclosed, wherein the gasket comprises a series of protruding projections which vary from a visually detectable, defined direction when installed improperly. This invention has particular utility in manufacturing operations where improper gasket installation is difficult to detect during assembly, particularly in the automotive heat exchanger industry.
    Type: Grant
    Filed: February 20, 1991
    Date of Patent: December 31, 1991
    Assignee: Blackstone Corporation
    Inventors: Paul K. Beatenbough, Lavoyce G. Dey, David J. Twichell
  • Patent number: 5031924
    Abstract: A gasket and method for detecting the status of an installed gasket is disclosed, wherein the gasket comprises a series of protruding projections which vary from a visually detectable, defined direction when installed improperly. This invention has particular utility in manufacturing operations where improper gasket installation is difficult to detect during assembly, particularly in the automotive heat exchanger industry.
    Type: Grant
    Filed: November 30, 1989
    Date of Patent: July 16, 1991
    Assignee: Blackstone Corporation
    Inventors: Paul K. Beatenbough, Lavoyce G. Dey, David J. Twichell
  • Patent number: 4997035
    Abstract: This invention is to an improved method for reducing crevice corrosion in assembly joints of aluminum fluid handling devices, the improvement comprising, providing a series of spaced ribs at the assembly joint configured to intermittently resist engagement of components along an elongated assembly crevice sufficient to segment the crevice into a plurality of minor assembly crevices dimensioned to permit substantial mixing of fluid within the minor crevices with fluid being handled by the device. The invention has particular utility in automotive heat exchangers wherein crevices at joints where polymeric tanks are assembled to aluminum metal headers are susceptible to crevice corrsion.
    Type: Grant
    Filed: April 2, 1990
    Date of Patent: March 5, 1991
    Assignee: Blackstone Corporation
    Inventors: Paul K. Beatenbough, David J. Twichell, Lavoyce G. Dey
  • Patent number: 4501321
    Abstract: A charge air cooler is provided made up of a plurality of spaced generally parallel turbulators, each said turbulator comprising an outer channel member having a bottom wall and two transverse side edges, an inner channel member having a bottom wall and two transverse side edges, the side edges of the inner channel interfitting closely within the side edges of the outer channel member, an accordian shaped fin assembly between said channels having side edges of a plurality of accordian folds in contact with the bottom wall of both the inner and outer channel members, a transverse heat exchanger fin assembly between adjacent turbulators, frame means surrounding said turbulators and heat exchangers, header means at each end of said turbulators, and flange means around the periphery of each said header means forming therewith one of an inlet and outlet well whereby the turbulator ends may be operatively connected to a source of fluid to be cooled.
    Type: Grant
    Filed: November 10, 1982
    Date of Patent: February 26, 1985
    Assignee: Blackstone Corporation
    Inventors: John D. Real, David J. Twichell, Lauren R. Weed