Pat Harrington, actor, comedian

Pat Harrington Jr., 86, an actor and comedian who portrayed the farcically macho building superintendent Dwayne Schneider in

One Day at a Time

, a sitcom that explored sexism, harassment and other tribulations through the lens of a divorced working woman and her two teenage daughters, died Wednesday.

His daughter Tresa Harrington announced the death on her Facebook page but did not provide other details. In November, she wrote that he had Alzheimer's disease and was in rapidly declining health.

Although billed as a supporting actor on One Day at a Time, Mr. Harrington provided such welcome comic relief that the program's popularity and longevity - it aired on CBS from 1975 to 1984 - was owed as much to him as to anyone. Years afterward, producer Norman Lear, who also created All in the Family, said Mr. Harrington "turned out to be the comic strength of the show."

Seemingly coming from nowhere - he was a total unknown to Lear when the show was being cast - Mr. Harrington was in fact a seasoned comic performer. His father had been a son-and-dance man in vaudeville and on Broadway, a late-night carousing companion of fellow Irish American entertainers such as Bing Crosby, Pat O'Brien and James Dunn.

"They'd sit down for eggs as I'd be going off to parochial school," Mr. Harrington once recalled.

In the late 1950s, his talent for wisecracking and mimicry brought him influential admirers such as Jonathan Winters, Jack Paar, Steve Allen and Danny Thomas. He subsequently worked in nightclubs, released comedy albums, and won small roles in films.

But it was One Day at a Time that made Harrington a household name during its protracted prime-time run.

The star was Bonnie Franklin, playing an independent-minded divorced woman in Indianapolis who struggles to raise two willful daughters (played by Mackenzie Phillips and Valerie Bertinelli). Set against the second wave of feminism, the show explored previously taboo sitcom subjects such as divorce, rape, teenage pregnancy and menopause.

Daniel Patrick Harrington Jr. was born in Manhattan on Aug. 13, 1929. He went to a Catholic military school and graduated from Fordham University, where he also later received a master's degree in political philosophy. After Air Force service, he began working in the NBC mail room, a job he parlayed into a junior advertising salesman position for the network.

He often entertained clients at Toots Shor's, the Manhattan watering hole, where, as the evenings wore on, he liked to trot out various voices and characters. He had his greatest success conjuring a fictional Italian immigrant named Guido Panzini, part of a gag he honed over many years and many drinks.

His first marriage, to Marjorie Gortner, with whom he had four children, ended in divorce. In 2001, he wed Sally Cleaver, an insurance executive.