Granted Patent
Utility
US 4,495,970 · App. 06/485,865
Large diameter plastic pipe
Inventors:
Harold T. Pate, William R. Laney, Donald H. Shell
Patented Case
View Patent ↗
Granted: Jan 29, 1985
Filed: Apr 18, 1983
Inventors
Harold T. Pate
William R. Laney
Donald H. Shell
Assignee (at issue)
Thyssen-Bornemisza, 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.