The damper flapper could control a coal fire furnace by operating the furnace damper from a thermostat. In 1885, Butz decided to patent his heat controller and establish a company to make and sell it. It is believed that Mendenhall urged Butz to patent, manufacture, and sell the damper flapper. The patent attorneys who assisted Butz in preparing the application were Amasa Paul, Rufus Sanford, and T. Dwight Mervin. A group of investors, known as Hay & Company Investors and Business Brokers provided Butz with the capital required to incorporate Butz Thermoelecric Regulator Company on April 23, 1886. May 4, 1886, Butz's patent was granted.