Granted Patent
Utility
US 4,860,995 · App. 07/183,652
Valve element for use in pumps for handling fluids containing abrasive materials
Inventor:
John Thomas Rogers
Patented Case
View Patent ↗
Granted: Aug 29, 1989
Filed: Apr 19, 1988
Inventor
John Thomas Rogers
Assignee (at issue)
Utex Industries 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.