It was late in the afternoon of the day that Barney B. Clark died that his widow, Una Loy, says she realized for the first time that her husband had suffered enough.

"He never gave up, never stopped trying," Mrs. Clark said today as she and members of her family met with reporters at a Mormon chapel near the family home in a suburb of Seattle.

"We never discussed letting go . . . ," she said. "About 4 in the afternoon the day he died, at that point I felt he had had enough. I was happy to see him at peace."

Clark, a 62-year-old retired dentist who last December became the world's first recipient of a permanent artificial heart, died Wednesday night at a Utah hospital from collapse of his circulatory system and failure of several organs.

Today, with her three children--Stephen, a surgeon, Gary and Karen--at her side, Mrs. Clark described the 112-day ordeal in Salt Lake City after her husband received his mechanical heart.

For her husband, who doctors said would have died had the artificial heart not been implanted, the days after the surgery were filled with moments of "tenderness and warmth and despair and frustration," she said. For her part, the stress was so great that "I had a hard time realizing what day of the week it was."

She recounted in some detail the various setbacks her husband suffered: the seizures, the air leakage, the broken heart valve.

"As time went on he had simply nosebleeds," she said. "The nosebleeds were the hardest for me."

"There were days that were good, days when he seemed to be anticipating getting well and going home," she said. But these would be followed by another setback.

Still, all of the Clarks emphasized today that they thought the operation was a success and that research on the artificial heart should continue.

"The artificial heart is a very valid concept," said Stephen, who described times when his father was without pain and discomfort, was lucid and ambulatory.

Mrs. Clark said she would urge the family of the next artificial heart recipient to participate in the program, to "go for it."

She said she doubted that doctors would select someone as ill as her husband, who suffered from emphysema and degenerative heart disease, as the next recipient.

"They gave him an 18-year-old heart in a 62-year-old man," Mrs. Clark said. "You cannot take a man whose organs are in such delicate condition. The heart works but you cannot rejuvenate the other organs."

Mrs. Clark said she stayed with her husband from 8 a.m. until 11 at night while he was hospitalized, and they talked about "common ordinary things."

"Barney wanted news of his children, news of his five grandchildren, to be kept up to date with what was going on back home. I don't remember one very serious or dramatic conversation."

The weekend before his death, the children visited, and they laughed and joked with their father, she said.

Asked how they would respond to those who said the implant had merely postponed Clark's death for 112 days, Stephen Clark responded: "We had a chance to be with dad that we wouldn't have had."

He added that his father wanted to obtain "a certain quality of life" so that he might return home pain-free.

"We never attained that particular hope," he said. "But we wouldn't say it was unsuccessful nor that it was not worthwhile."

Mrs. Clark said there were times that she wouldn't want to have to live through again. "One thing that comforts me now is that he wanted to do this," she said of her husband, whom she met in 7th grade when she was 12 years old.

"I'd like my husband to be remembered as just what he was--a warm, loving father, a loving husband and a man who was just like all of you . . . a common man who worked hard for his living and had a lot of pride in his family," she said.

Funeral services will be held here Tuesday.