In 1933, Samuel Blanc created a funny-looking sewer cleaning machine from a 1/6 HP Maytag washing machine motor, roller skate wheels and 3/8 inch cable to turn the blades. The device used a combination of special blades or "knives" to cut tree roots out of sewer lines. No digging was required. A year later, Sam's wife Lettie christened the prototype the "Roto-Rooter." Founded in 1935, Roto-Rooter is the largest provider of plumbing, drain cleaning and water cleanup services in North America. In 1980, the Blanc family sold Roto-Rooter to Chemed Corporation, and Roto-Rooter moved its headquarters to Cincinnati but continued to manufacture the famous Roto-Rooter drain cleaning machines, cables, blades and other parts at its own factory in West Des Moines, Iowa. Roto-Rooter operates businesses in more than 100 company-owned branch and independent contractor territories and approximately 400 independent franchise operations, serving approximately 90% of the U.S. population and parts of Canada. Master independent franchise operations have been established in Indonesia/Singapore and the Philippines.