Granted Patent
Utility
US 4,054,403 · App. 05/714,549
Extruder with dual flighted extrusion screw
Inventors:
Robert L. Hornbeck, Norman Brozenick
Patented Case
View Patent ↗
Granted: Oct 18, 1977
Filed: Aug 16, 1976
Inventors
Robert L. Hornbeck
Norman Brozenick
Assignee (at issue)
BorgWarner 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.