Cox's business career began in 1948 as vice president of sales and marketing at In-Sink Erator Manufacturing Co. in Racine, Wis. Though the founder of In-Sink-Erator, James Hammes, invented the disposer, it was through the marketing strategy of Cox that the invention became a household convenience.

After World War II, many municipalities banned garbage disposers citing possible sanitation problems with sewage lines and treatment plants. However, Cox fought rumors of harmful effects by selling disposers cross-country, pointing out features and benefits. By the early 1950s, most municipalities had revoked their ban on disposers.

Included in Cox's strategy was his insistence that plumbing contractors were the ones to convince homeowners to install a garbage disposer, even though his competitors sold through appliance distributors. More than 4 million disposers are sold annually today, according to In-Sink-Erator.

Cox retired from In-Sink-Erator in 1987 after serving as executive vice president. He also served as chairman of the American Home Appliance Manufacturers Association in 1984 and worked closely with the American Society of Sanitary Engineers. Through his relationship with the National Association of the Plumbing-Heating-Cooling Contractors Auxiliary, an award was named in his honor. The Robert M. Cox Award is presented annually to applaud humanitarian efforts.

He is survived by his wife, two daughters and three grandchildren.