CHICAGO — Pro Football Hall of Famer and former Heisman Trophy winner Paul Hornung sued equipment manufacturer Riddell on Thursday, saying football helmets that he wore during his professional career in the 1950s and ’60s failed to protect him from brain injury.

Attorneys for the 80-year-old Hornung filed the civil lawsuit in Cook County Circuit Court in Chicago, naming the Rosemont-based company as the defendant. It seeks unspecified damages.

Hornung suffered multiple concussions as a running back for the Green Bay Packers and has been diagnosed with dementia, the lawsuit says. It said that the neurodegenerative disease has been linked to repetitive head trauma.

Concussion lawsuits from athletes have become more common in recent years amid growing awareness about the long-term consequences of repeated blows to the head and Riddell is also fighting litigation elsewhere. But suits from athletes whose playing days were as far back as the 1950s are rare.

Riddell began producing helmets out of plastic in 1939, touting them as safer alternatives to ones — more common at the time — fashioned from leather, according to the eight-page filing. Hornung, it says, wore a leather helmet when he played for Notre Dame in college but switched to the Riddell-made plastic helmets in the NFL.

Erin Griffin, a spokeswoman for Riddell, declined comment in an email, saying, “It’s our policy not to comment on pending litigation.”

Hornung won the Heisman in 1956 while at Notre Dame, where he played quarterback. The Packers selected him as the No. 1 overall draft pick a year later. He was the NFL MVP in 1962 and he played on four championship teams (1961, ’62, ’65 and ’66).