IP Library › Granted Patent US 4,348,794
Granted Patent Utility
US 4,348,794 · App. 06/168,033

Double-walled finned heat transfer tube

Inventors: Sung-Choon Kim, Marvin P. Schwartz
Patented Case View Patent ↗
Granted: Sep 14, 1982 Filed: Jul 11, 1980
Inventors
Sung-Choon Kim
Marvin P. Schwartz
Assignee (at issue)
International Telephone and Telegraph Corporation

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.

Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 4,348,794
App. No.
06/168,033
Filed
1980-07-11
Granted
1982-09-14
Kind
A