Patents by Inventor Hendrik Lenten

Hendrik Lenten 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: 4887398
    Abstract: A hydraulic buffer, filled with a compound having the behaviour of a liquid to a certain extent, mounted beneath the foundation of buildings or other structures in order to sustain the structures during earthquakes. The buffer is made from reinforced flexible material and consists of two parallel circular plates (1,2), on the circumference connected to each other by a torus (5), in such a way that the torus and the drum-like space between the circular plates communicate freely, while the axis of the torus is upright, in order to permit the buffer to accommodate relative transverse movement between the circular plates.
    Type: Grant
    Filed: August 15, 1988
    Date of Patent: December 19, 1989
    Inventor: Hendrik Lenten
  • Patent number: 4578038
    Abstract: A thrust device for manually advancing a water craft over a water surface includes a stick-like grip forming part of a stick carrying a thrust apparatus made of a flexible, substantially circular foil provided with radial stiffening members attached at equally spaced intervals along its circumference. A concentric stub-like tubular opening connects the foil to the stick near one end of the stick to be inserted in the water, and flexible tension members connecting the circumference of the foil to the one end of the stick define a maximum angle between the foil face and the stick when the one end of the stick is thrust into the water. Each tension member has one end attached to the edge of the circular foil and a second end. The second ends of all the tension members are led through a central hole in a cover slipped over the end of the stick and are joined into a junction larger than the hole in the cover.
    Type: Grant
    Filed: June 17, 1985
    Date of Patent: March 25, 1986
    Inventor: Hendrik Lenten