Cyril and Louis Keller, the brothers who invented the world’s first compact loader – the basis of what would become the Bobcat skid-steer loader – have been selected as posthumous 2023 inductees to the National Inventors Hall of Fame (NIHF) in the United States.
The NIHF annually recognises inventors, promotes creativity and advances the spirit of innovation and entrepreneurship. The honour has now been extended to Louis, who died in 2010 aged 87, and Cyril who died aged 98 in 2020.
Between them, the brothers held six US patents, and the pair were inducted into the Association of Equipment Manufacturers Hall of Fame in 1999 and the Minnesota Inventors Hall of Fame in 2004.
In the 1950s, the Keller brothers operated a small machine-blacksmith shop at Rothsay in Minnesota, building and repairing machinery for local farmers. A farmer approached them with a need for 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 response, in 1957 the Kellers built a three-wheeled loader with two drive wheels in front and a caster wheel at the rear – the predecessor to the modern skid-steer loader. The work took six weeks using mechanical parts from local junkyards and bars from the old Rothsay jail for the manure fork teeth.
The machine featured the Kellers’ patented clutch system, operated with two hand levers, that made it possible to put one side of the loader into forward and the other side into reverse, without the use of a transmission gearshift or a steering wheel. The loader could turn completely around in a circle the size of its own length, with one front wheel moving forward and the other moving in reverse, pivoting around the caster wheel.
The loader came to the attention of the Melroe Manufacturing Company (now Bobcat), which invited the Kellers to demonstrate their invention on its stand at the 1958 Minnesota State Fair. After a successful demonstration, Melroe was awarded exclusive manufacturing rights to the machine on a royalty basis and it hired the Keller brothers to refine the design and put the machine into production.
To improve on the design of the loader, a second set of drive wheels was added to the back of the loader in 1960. This four-wheel-drive unit, the M400, became the world’s first true skid-steer loader.
The machine’s toughness, quickness and agility later resulted in the adoption of the Bobcat brand name.
Louis Keller’s son, Joe, said the Bobcat loader had positively impacted the lives of thousands of employees who had worked for the company, dealers who sell the machines, and customers who use the equipment every day to build their livelihood.
“While we may not always realise its impact, it’s an integral part of our everyday life,” he added, “from supporting farm operations that result in food on our tables to hauling materials around a jobsite building our homes and offices.”
As Bobcat celebrates 65 years since the invention of the machine that created the compact equipment industry, it has continued to forge the future of the industry through innovation and forward-thinking.
Bobcat now offers more than 100 products in the compact, grounds maintenance and industrial equipment industries, and produces more than 150 families of attachments.
