Patents by Inventor Marcel Charles Lefebvre

Marcel Charles Lefebvre 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).

  • Balanced ventilation doors
    Patent number: 6361430
    Abstract: A pair of door-sections make up a mine ventilation door. The door-sections are hinged to the side-walls of the passage. One of the door-sections opens upstream and the other downstream, so one is blown open, and the other blown closed, by winds passing through the passage. A linkage couples the door-sections, and harnesses the blow-open force and balances it against the blow-closed force, whereby only a small actuation force is needed to open and close the doors. The linkage ensures that the arcuate travels of the two door-sections are equal, or otherwise correspond.
    Type: Grant
    Filed: February 20, 2001
    Date of Patent: March 26, 2002
    Inventors: Wayne William Kitching, Marcel Charles Lefebvre
  • Balanced ventilation doors
    Publication number: 20010007814
    Abstract: A pair of door-sections make up a mine ventilation door. The door-sections are hinged to the side-walls of the passage. One of the door-sections opens upstream and the other downstream, so one is blown open, and the other blown closed, by winds passing through the passage. A linkage couples the door-sections, and harnesses the blow-open force and balances it against the blow-closed force, whereby only a small actuation force is needed to open and close the doors. The linkage ensures that the arcuate travels of the two door-sections are equal, or otherwise correspond.
    Type: Application
    Filed: February 20, 2001
    Publication date: July 12, 2001
    Inventors: Wayne William Kitching, Marcel Charles Lefebvre