Sheffield Laboratories holds a valuable patent (No. 758-6002-1A) on a precipitator that prevents certain types of air pollution. Sheffield 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 Sheffield patent number 758-6002-1A is as follows.

20112012

Research conducted to develop precipitator

$370,000

Jan. 2013

Design and construction of a prototype

85,800

March 2013

Testing of models

37,800

Jan. 2014

Fees paid engineers and lawyers to prepare patent application;

patent granted June 30, 2014

56,100

Nov. 2015

Engineering activity necessary to advance the design of the

precipitator to the manufacturing stage

86,000

Dec. 2016

Legal fees paid to successfully defend precipitator patent

37,800

April 2017

Research aimed at modifying the design of the patented precipitator

38,800

July 2021

Legal fees paid in unsuccessful patent infringement suit against a

competitor

34,000

(a)		December 31, 2014		$enter a dollar amount
(b)		December 31, 2018
(c)		December 31, 2021