Patents by Inventor Martien de Graaf

Martien de Graaf 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: 5287651
    Abstract: Apparatus for the greenhouse cultivation of flower bulbs wherein the bulbs are placed in pockets (6) made in a hydrophilic mineral wool felt (5). The pockets (6) are formed at regular intervals and open only on one face of the felt. The opening formed in each pocket is of a slightly smaller size than the maximum diameter of a bulb (3) intended to be received in the pocket. The depth of each pocket is sufficient for the bulb (3) positioned therein to penetrate the pocket at least to the level of its largest section.
    Type: Grant
    Filed: January 31, 1991
    Date of Patent: February 22, 1994
    Assignee: Isover Saint-Gobain
    Inventor: Martien de Graaf
  • Patent number: 5060419
    Abstract: A substrate of limited dimensions consisting of mineral fibers for out-of-ground cultivation is used for the cultivation phase corresponding to the development of seedlings. This substrate, of general parallelepipedic shape, exhibits small surface protuberances on its lower face which separate it from the ground on which it rests. The protuberances can be feet disposed on the lower face of the substrate, or edges formed by providing the substrate with a concave lower face. The substrate according to the invention makes it possible to improve out-of-ground cultivation conditions.
    Type: Grant
    Filed: March 21, 1990
    Date of Patent: October 29, 1991
    Assignee: Isover Saint-Gobain
    Inventors: Martien de Graaf, Jacques Vos, Dominique Plantard