Patents by Inventor Jan Harpula

Jan Harpula 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).

  • Quick-hardening core and molding sand composition, and a method for its hardening
    Patent number: 3943089
    Abstract: A quick-setting core and molding sand comprising quartz sand, a binder and an adsorbent or absorbent. The binder is a solution of a binding agent such as polystyrene, polyvinyl acetate or the like in an appropriate organic solvent. After molding, the sand is hardened by means of blowing it with an inert gas, preferably air or applying a suction thereto. The time of hardening is very short and depends upon the size of a mold or a core which is being made.
    Type: Grant
    Filed: May 24, 1974
    Date of Patent: March 9, 1976
    Assignee: Instytut Odlewnictwa
    Inventors: Jan Harpula, Jur Piszak, Mieczyslaw Debski, Tadeusz Rzepa, Jerzy Sliwa, Andrzej Heryan