The ten-key, printing Sundstrand adding machine developed from the work of Rockford, Illinois, machine tool makers and inventors Oscar and David Sundstrand, who first put an adding machine on the market in about 1915. In January of 1927, the assets and business of Sundstrand Corporation were acquired by the Elliott Fisher Company of New York, a maker of accounting machines. At the end of that same year, the combined firm merged with the Underwood Typewriter Company, also of New York. By 1933, Underwood Elliot Fisher Company sold three forms of accounting machines, patterned after earlier Underwood, Elliott Fisher and Sundstrand products. In 1959, the firm, by then known as Underwood Corporation, was acquired by the Italian business machines manufacturer Olivetti.