Granted Patent
Utility
US 5,540,581 · App. 08/449,840
Mold for injection molding a thermoplastic part free from sink marks using a void inducing member
Inventors:
Hiroshi Aida, Ryohei Hazawa
Patented Case
View Patent ↗
Granted: Jul 30, 1996
Filed: May 24, 1995
Inventors
Hiroshi Aida
Ryohei Hazawa
Assignee (at issue)
NIPPON STEEL CHEMICAL CO., 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.