IP Library › Granted Patent US 4,614,968
Granted Patent Utility
US 4,614,968 · App. 06/349,062

Contrast smoke detector

Inventors: William J. Rattman, Stephen Marchetti, Aaron A. Galvin
Patented Case View Patent ↗
Granted: Sep 30, 1986 Filed: Feb 16, 1982
Inventors
William J. Rattman
Stephen Marchetti
Aaron A. Galvin
Assignee (at issue)
American District Telegraph Company

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 4,614,968
App. No.
06/349,062
Filed
1982-02-16
Granted
1986-09-30
Kind
A