Patents by Inventor Harm W. Holman

Harm W. Holman 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).

  • Draining pavement element, method for manufacturing it and pavement made with it
    Patent number: 5487620
    Abstract: Pavement element such as a tile with an upper porous layer (2), below that a liquid-tight layer (3) and possibly there below a heavy layer (4). In order to keep a floor laid with suchlike elements well liquid-tight at the level of the liquid-tight layers sealing means (6) are provided between this layer (3) or one element and the same layer (3') of an adjacent element. Preferably these means consist in a rib or protrusion, which may cover the complete height of the liquid-tight layer. Preferably the porous layer is formed from particles of the same size having an irregular shape and the liquid-tight layer from particle from different particle sizes, such that the particles attain a high filling degree.
    Type: Grant
    Filed: June 28, 1994
    Date of Patent: January 30, 1996
    Assignees: Terra IJssel B.V., Harm Willem Holman
    Inventor: Harm W. Holman
  • Device for lowering a load along a line
    Patent number: 4588046
    Abstract: Escape device comprising a holder 1 in which is guided a flat belt 23 and which accommodates at least one brake shoe 12a on which a force is exerted depending upon the weight of the load and which is directed toward the belt 23.
    Type: Grant
    Filed: November 5, 1984
    Date of Patent: May 13, 1986
    Assignee: van der Neer International B.V.
    Inventors: Abram P. van der Neer, Harm W. Holman