The Franklin Institute Logo
Case Files logo

Charles F. Kettering: Science of Automotive Engineering, 1936

Other Developments

Kettering had invented the Delco Light Generator which revolutionized rural life by extending the hours of light available for work and recreation. Simply moving the electric switch for the gasoline engine caused the batteries to fully charge and recharge. In 1918, a three kilowatt light plant could be powered by a one-cylinder 5-horsepower engine.

Another material developed by Midgley and Kettering with enormous implications was Freon, a group of halocarbon compounds that replaced the toxic ammonia and sulfur dioxide as refrigerant. Refrigerator compressors working from chemicals that were non-flammable, non-toxic, and chemically inert gained wide acceptance and their use expanded the scope of food storage and, via air conditioning, extended the comfort and usable hours of workers.

U.S. Patent No. 1,886,339 for dichlorodifluoromethane, the first Freon, was issued to Frigidaire, the General Motors Division headed by Kettering, on December 31, 1928. Dupont Company undertook the commercial manufacture of Freons and the line grew to over twenty different products differentiated by the length of the aliphatic carbon chain and the degree of chlorine and fluorine substitution. Their applications widened to aerosol propellants and inhalers. Freon use was phased out as it was discovered in the 1970s that the compounds deplete the earth's protective ozone layer.