Patents Assigned to Valentine Match Plate Company
  • Production of plaster molds by microwave treatment
    Patent number: 4126651
    Abstract: Metal casting components, e.g. molds and cores, are produced from a compacted mass of plaster by microwave treatment while shielded by a heat insulating medium, e.g. glass fiber matting, which freely transmits microwave radiation as well as water vapor and steam. A casting component dried by this method is completely calcined, and the resulting component will promote cast reproduction of its surface pattern with maximum fidelity of detail.
    Type: Grant
    Filed: March 22, 1977
    Date of Patent: November 21, 1978
    Assignee: Valentine Match Plate Company
    Inventor: James M. Valentine
  • Production of plaster molds by microwave treatment
    Patent number: 4043380
    Abstract: Metal casting components, e.g. molds and cores, are produced from a compacted mass of plaster by a two-stage drying treatment in a microwave oven with an intermediate cooling step whereby the plaster is completely calcined, and the resulting component will promote cast reproduction of its surface pattern with maximum fidelity of detail.
    Type: Grant
    Filed: September 2, 1975
    Date of Patent: August 23, 1977
    Assignee: Valentine Match Plate Company
    Inventor: James M. Valentine