Granted Patent
Utility
US 4,693,879 · App. 06/785,680
Ultrasonic vibration sieving apparatus and process for purifying carbon black by using the apparatus
Inventors:
Shushichi Yoshimura, Yasunori Hiwatashi, Hiromu Kobayashi, Hozo Yamazaki, Nobu Nishino, Teruji Tahara, Hidenobu Kobayashi
Patented Case
View Patent ↗
Granted: Sep 15, 1987
Filed: Oct 9, 1985
Inventors
Shushichi Yoshimura
Yasunori Hiwatashi
Hiromu Kobayashi
Hozo Yamazaki
Nobu Nishino
Teruji Tahara
Hidenobu Kobayashi
Assignee (at issue)
Mitsubishi Chemical Industries, Ltd.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.