Granted Patent
Utility
US 6,516,142 · App. 09/781,456
Internal heating element for pipes and tubes
Inventors:
Mike Grant, Clifford D. Tweedy, John W. Schlesselman
Patented Case
View Patent ↗
Granted: Feb 4, 2003
Filed: Feb 12, 2001
Inventors
Mike Grant
Clifford D. Tweedy
John W. Schlesselman
Assignee (at issue)
Watlow Polymer Technologies
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.