Inventors of Iconic Bobcat tractor Inducted into National Inventors Hall of Fame

The first version of the Keller Loader was invented to meet the needs of a local turkey farmer. (Image Source: Bobcat Co.)

The brothers who invented the world’s first compact loader, which later became known across North America as the Bobcat skid-steer loader, have been selected as 2023 inductees for the National Inventors Hall of Fame (NIHF).

In the 1950s, brothers Cyril and Louis Keller ran a small machine and fabrication shop building and repairing machinery for local farmers in Minnesota. A local farmer came to them with a problem—he needed a self-propelled loader light enough to be lifted to the second floor of a turkey barn and small enough to clean around the barn’s upright poles. In 1957, the Kellers built a three-wheeled loader with two drive wheels in front and a caster wheel in the rear. This was the precursor to the modern skid-steer loader.

Melroe Manufacturing Co. In Gwinner, N.D. (now Bobcat Co.) took note of the development and invited the Kellers to show their invention in their booth at the Minnesota State Fair in 1958. The brothers later awarded Melroe the exclusive manufacturing rights to the machine on a royalty basis. The company hired the Keller brothers to refine their design and put the machine into production.

The M440 prototype, invented in 1962. (Image Source: Bobcat Co.)

The second-generation loader—named the M400 and developed in 1960—included a second set of drive wheels added to the back of the machine, making it a true four-wheel drive and becoming the world’s first skid-steer loader. Skid-steer describes the steering system which enables the machine to turn within its own length. Later, it was renamed the Bobcat because of the machine’s toughness, quickness and agility.

“We are proud of our inventors’ spirit of innovation, and while we remain grounded in our humble roots, we continue to push the boundaries to offer customers increased choice, improved performance and advanced technology to work smarter,” said Mike Ballweber, president, Bobcat Co. North America.

2023 marks the 50th anniversary of NIHF’s founding, when Thomas Edison was the sole inductee.

Acknowledging the award on behalf of his father Louis and uncle Cyrill, Joe Keller said, “This recognition is a great honor to dad and Cyril’s families, but it is not just for us. It is a recognition for all of the early and current Bobcat employees who have helped bring our little ‘Keller loader’ to be the Bobcat machine it is today. It has been a great honor to have had a front-row seat watching this invention revolutionize the way work gets done around the world.”

Now headquartered in West Fargo, N.D., Bobcat Co. has grown to manufacture many pieces of compact equipment, including loaders, excavators, compact tractors, utility products, telehandlers, mowers, attachments, implements, parts, and services.

Founded in 1973 in partnership with the United States Patent and Trademark Office, the National Inventors Hall of Fame (NIHF) is a U.S. nonprofit organization that recognizes inventors and inventions and provides a national, hands-on educational programming and collegiate competitions focused on the exploration of science, technology, engineering and mathematics.