Fields Laboratories holds a valuable patent (No. 758-6002-1A) on a precipitator that prevents certain types of air pollution. Fields does not manufacture or sell the products and processes it develops. Instead, it conducts research and develops products and processes which it patents, and then assigns the patents to manufacturers on a royalty basis. Occasionally it sells a patent. The history of Fields patent number 758-6002-1A is as follows.

Date		Activity		Cost
20082009		Research conducted to develop precipitator		$382,000
Jan. 2010		Design and construction of a prototype		85,400
March 2010		Testing of models		57,400
Jan. 2011		Fees paid engineers and lawyers to prepare patent application;
		patent granted June 30, 2011		66,300
Nov. 2012		Engineering activity necessary to advance the design of the
		precipitator to the manufacturing stage		95,000
Dec. 2013		Legal fees paid to successfully defend precipitator patent		57,400
April 2014		Research aimed at modifying the design of the patented precipitator		58,400
July 2018		Legal fees paid in unsuccessful patent infringement suit against a
		competitor		36,000