Patents by Inventor David Michael Clark

David Michael Clark 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).

  • Vacuum cleaner
    Patent number: 5720076
    Abstract: A vacuum cleaner has wheels which can rotate in one direction only, when the body of the cleaner is inclined to the horizontal, such as when the cleaner is disposed on a flight of stairs. A prop provides alternative or additional support by engaging the stair surface. The invention reduces the possibility of the cleaner rolling off the stair tread and falling down the stairs.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: February 24, 1998
    Assignee: Goblin Limited
    Inventor: David Michael Clark