Parkhurst & Oliff
Apparatus for pressure molding firebrick
 A fluid operated press having opposed first and second fluid chambers is employed for compressing a mixture of desired brick ingredients in a mold. Pressurized fluid, preferably hydraulic oil, is first delivered to the first fluid chamber of the press to cause the same to exert a prescribed pressure on the mixture. Then, with this prescribed pressure maintained, the pressurized fluid is directed alternately into the first and second fluid chambers at rapid intervals, with the result that the press imparts vibratory motion to the mixture being held under pressure. In a preferred embodiment, the selective delivery of the pressurized fluid to the fluid chambers of the press is controlled by a servomechanism, constantly comparing a reference pressure signal with an actual pressure signal representative of the actual pressure being exerted by the press and actuating a servovalve so as to make the difference between the reference and actual pressure signals zero. 
Shinagawa Shirorenga Kabushiki Kaisha
B
B28B
inventional
Yoshio Shinji Takashi Mitsukuni
Nakamori Nishida Otsuka Sato