Legal Notice

Client Successes

A few stories from our satisfied clients!


     For more than eighty years, the Sellner family has relied on the expertise of the attorneys at Moore & Hansen to help it protect and pass on its legacy of designing safe and enjoyable amusement rides for people of all ages. If you go to any amusement park, state fair or traveling carnival around the country, you will almost certainly find a Tilt-A-Whirl® ride ready to take you for a spin. The story of the Tilt-A-Whirl® is a prime example of the dependability and long-term partnership that clients can count on from Moore & Hansen.

     Herbert Sellner made his living creating enjoyable, yet safe, amusement park rides and attractions. In 1925, Seller came to the Williamson Law Firm, the forerunner of Moore & Hansen, to get help in obtaining a patent for a toboggan slide and toboggan (U.S. Pat. No. 1,702,091) that could coast across land or water after leaving its track. Always looking for new ways to attract and entertain people, Sellner patented several more rides through the firm before creating the one that would carry his family into the 21st Century.

    The Tilt-A-Whirl® idea began as a way to amuse his young son. With the boy sitting on a stool atop the family's kitchen table, Sellner would then spin him around by rocking the table back and forth. To mimic the unpredictable dipping and spinning of his table-top prototype on a larger scale for multiple riders, Sellner created an undulating track over which a number of cars would travel. By mounting each car on a freely-spinning plate, the cars would begin to spin as they encountered the hills and valleys of the track. The distribution of the weight of each passenger affects the speed and direction of each car's spin, causing the cars to spin unpredictably. This development is the key to the success of the ride. After repeated rides, even the most thrilling roller coasters become predictable and begin to lose their appeal. The rotation of cars on a Tilt-A-Whirl� amusement ride, however, is completely random. Riders never know what will happen next, which makes every ride as exhilarating as the first.

    Before its debut at the Minnesota State Fair in 1927, Sellner worked with our firm to patent his new ride and also register the distinctive name he created to market it. Described as "a new and improved amusement apparatus," the Tilt-A-Whirl® would "furnish pleasurable and unexpected sensations, may be operated economically, and will furnish a high degree of safety." Moore & Hansen helped Sellner receive two patents for his invention (U.S. Pat. Nos. 1,745,719 and 1,707,687).

    Although the original patents have long since expired, Tilt-A-Whirl® still possesses strong brand recognition in America and overseas, capturing both the essence of the ride's thrills and distinguishing it from lesser imitations. The attorneys of Moore & Hansen continue to work side-by-side with the Sellner family, now in its fourth generation of operating the Sellner Manufacturing Co. in Faribault, Minnesota, protecting its trademarks and securing patents for new rides and amusements. Whether your ideas start out on a work bench, on the kitchen table or as the kitchen table, you can count on Moore & Hansen to be ready to handle your ideas whenever you need assistance.

The Skid-Steer Drive System

The Skid-Steer Drive System
The Skid-Steer Drive System is an essential component of a numerous commercial, industrial and agricultural vehicles. Found on front-end loaders, forklifts, and excavators, the skid-steer is desirable for its agile handling and zero-point turning radius which allows vehicles to maneuver in tight spaces on a variety of terrains. Louis and Cyril Keller, of Rothsay, Minnesota, developed the predecessor of the skid-steer, a self-propelled three-wheel loader, for a neighbor in 1957. The neighbor operated a turkey farm and needed something that could turn in very tight spaces but that was also light enough to drive on both levels of his barn. The key to the invention was a unique transmission that allowed the two main wheels to drive independently forward, backward or remain neutral. This new transmission allowed the loader to rotate a full 360 degrees within its own length and was so successful that the Kellers immediately sought patent protection with the assistance of Williamson, Schroeder and Palmatier, a forerunner to Moore & Hansen. The Kellers received U.S. Pat. No. 3,151,503 and began making loaders for other poultry farmers before taking their loader to the Minnesota State Fair in 1958.

The Melroe brothers saw the interest in the Keller loader on display at the fair and were so impressed with the design that they immediately negotiated an exclusive license to begin manufacturing the loaders before the end of the fair. The brothers came to work for the Melroe Manufacturing Co. in Gwinner, North Dakota to continue improvements to the loaders. Several years later, Louis sought to develop a four-wheeled loader that would be stable on a wider variety of surfaces than the current three-wheeled models in production. The problem was that the steering mechanics for the three-wheeled loaders did not transfer, until Louis finally figured out a solution in 1961. By shifting the center of gravity for the loader to the back, it allowed the back wheels to drive when unloaded, and the front wheels to drive when loaded. The non-driving wheels simply skid along until the weight shifts-hence the phrase "skid-steer."

The success of this new invention was immediately apparent, but also created a strong incentive for imitators, especially when questions arose as to the validity of the patent for the four-wheel design (U.S. Pat. No. 3,231,117), which was filed by Melroe's attorney in the fall of 1962. The Melroes sold their company, and the rights to manufacture the skid-steer loaders under the Bobcat� brand, to the Clark Equipment Co. in 1969. In 1973, after more alleged infringers appeared, disputing the company's patent, Clark stopped paying royalties to the Kellers, and filed a declaratory judgment action arguing that an invalid patent created no duty to continue it royalty obligations. The Kellers, still clients of the firm, then known as Williamson, Bains, Moore & Hansen, responded and argued that Melroe missed the one-year post-sale deadline for patent applications and that Clark, having assumed all liabilities and obligations of Melroe, was bound to continue its royalty payments for as long as the patent would have been valid.

Malcolm Moore fought diligently for the Kellers, as first the district court and then the Eighth Circuit Court of Appeals issued rulings in the Kellers' favor. In 1984, the United States Supreme Court declined to hear Clark's appeal and the Kellers were finally given their due-along with a $3.5 million award for their royalties.

In the fifty years since the first Keller loader went to work in a Minnesota turkey barn, the Keller brothers and Moore & Hansen have continued to work together to patent a wide variety of new and useful inventions, from a removable track system for vehicles to an ice-fishing apparatus, to an extendable truck bed. In 2004, the American Society of Agricultural Engineers awarded the Keller brothers with a Historic Landmark of Agricultural Engineering recognizing the profound impact of their invention and its continually-evolving applications in a host of industries.