These days are not so happy for a handful of Happy Days cast members, who have launched a lawsuit against CBS Corp. over lost revenue from merchandise sales.

Marion Ross, Erin Moran, Tom Bosley's widow  Patricia Bosley, Anson Williams and Don Most are the plaintiffs named in the lawsuit filed Tuesday in Los Angeles.

The suit alleges that CBS failed to pay the actors their share of more than $10 million US in revenue from Happy Days-related products over the years.

The wide range of products includes typical offerings such as DVDs, board games and T-shirts, but also drinking glasses, greeting cards and even gambling machines.

"Happy Days epitomizes what is best in America, with the Cunningham family exemplifying the best of what a family can be," the lawsuit stated. "[The] defendants' actions epitomize what is worst in Corporate America."

The lawsuit claims that the actors had a contract that guaranteed them a certain percentage of any revenue from merchandise that features their names, voices or likenesses. However, CBS has failed to show the plaintiffs revenue reports, the filing said. 

Moran also claims that she was informed that no money was owed to her despite the introduction of new products, like a series of Happy Days slot machines unveiled in casinos about two years ago.

Henry Winkler and Ron Howard, two of the most prominent members of the cast, are not involved in the suit.

"We agree that funds are owed to the actors and have been working with them for quite some time to resolve the issue," the CBS consumer products unit said in a statement issued Tuesday.

Happy Days debuted in 1974 and, for the next 10 years, the sitcom offered an idealized portrait of 1950s America and revolved around the lives of the Midwestern Cunningham family.

With files from The Associated Press