Patents Assigned to Langdon Incorporated
  • Portion of ductwork
    Patent number: D521147
    Type: Grant
    Filed: March 24, 2005
    Date of Patent: May 16, 2006
    Assignee: Langdon Incorporated
    Inventors: Michael N. Sandman, Joseph P. Sandman
  • Portion of ductwork
    Patent number: D529598
    Type: Grant
    Filed: March 24, 2005
    Date of Patent: October 3, 2006
    Assignee: Langdon Incorporated
    Inventors: Michael N. Sandman, Joseph P. Sandman