Granted Patent
Utility
US 5,178,787 · App. 07/667,631
Lavatory cleaning block comprising N,N-dichloro dialkyl hydantoin and aluminum hydroxide
Inventors:
John Hung, Robert Carmello
Patented Case
View Patent ↗
Granted: Jan 12, 1993
Filed: Mar 11, 1991
Inventors
John Hung
Robert Carmello
Assignee (at issue)
BLOCK DRUG COMPANY INC.
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.