Minnesota Inventors Hall of Fame

Inductees

Cyril Keller & Louis Keller - 2004 Inductees

Cyril Keller
Cyril Keller
Louis Keller
Louis Keller

Cyril Keller (1922 - ) and Louis Keller (1923 - ) were innovative blacksmiths often called upon to solve problems for area farmers. In 1956, they built a three-wheeled loader to help a turkey grower clean manure out of his two-story barn. The loader was able to turn a complete circle within its own length, light enough to be lifted up to the second floor, and maneuverable enough to clean around poles. The Keller loader was the predecessor of the skid-steer loader. In 1958, the Kellers licensed their rights to the Melroe Manufacturing Company, and Melroe hired them. They refined their invention to pioneer the Melroe Bobcat® - the first, true, four-wheel-drive skid-steer loader. The "skid-steer" concept is a method of steering that is conceptually similar to a tracked vehicle - the two wheels on the same side move in unison. If both pairs of wheels are driven forward with the same speed, the loader moves forward, but if they are driven in opposite directions the loader will turn on itself. The clever aspect of the concept lies in the distribution of weight. Without a load, the center of gravity lies toward the rear axle near the engine, allowing the front wheels to skid around. If there is significant weight in the bucket, the center of gravity shifts to the front axle and the rear wheels skid around.

The new loader was called a Bobcat because it was like the prairie animal, it was "tough, quick, and agile." This invention has resulted in the employment of thousands of people throughout the world. "Lots of people use Bobcats to make their living," says Cyril Keller, "either making them or using them." More than 600,000 skid-steer loaders have been manufactured on Melroe’s assembly lines, now the Bobcat® Company, an Ingersoll-Rand business. Fortune magazine named the skid-steer loader to its "America’s Best" list - 100 American-made products that represent the best of their kind, anywhere in the world.

NOTE: These biographies have been compiled from information accompanying the nomination form submitted to the Minnesota Inventors Hall of Fame, information available on the Internet and from a variety of other sources.