Before the Korean War, Donald Mayer had a bit of a rebellious streak. He had never been a serious student up to that point, and while he was a freshman at the University of Minnesota, he considered himself a prime candidate for the draft. Rather than leave it to chance, he jumped in with both feet and joined the Air Force. Shortly before leaving for Korea, he married the woman who became his wife of 65 years, Alice.

His time in the Air Force gave him direction and focus, said his son, David Mayer of Bloomington.

“He was very, very driven and persistent in his approach to things,” David Mayer said. “He lived by example and the lessons he delivered were always subtle and understated, but they lasted a lifetime.”

Mayer, a loving and tireless family man who earned 12 U.S. patents as a mechanical engineer, died Aug. 6 of complications relating to Parkinson’s disease, dementia and COVID-19. He was 90.

Mayer, who was born in Chicago, returned to the U to complete his engineering degree after coming home from the war. In the early 1960s, he moved his growing family to a home in Bloomington, where he and his wife would stay until 2015.

He spent much of his career at Thermo King Corp. in Bloomington, where he earned his patents developing concepts that helped improve transport refrigeration units carried by truck, train and ship.

Mayer and his wife were avid square dancers and travelers. After he retired in 1992, they planned 12 trips to different places around the world. The 12th trip was to Korea, David Mayer said.

“Even though it looked so different, it really gave my mom something she could put into her mind and give her some perspective on all the letters she had received during the war,” he said.

Mayer proudly kept the car running and would fix anything that might go wrong at the family home, whether it was mechanical, electrical or plumbing.

Above all Mayer was a quiet, thoughtful teacher, whose lessons and wisdom might not even become clear until years down the road, his son said.

“I never feel more in touch with my parents than when I’m in a tough situation,” David Mayer said. “Eventually it sinks in that I was able to get out of those binds because of something they drilled or taught or expressed to me in a way that I could understand.”

Mayer is also survived by son Steven, daughter Linda, four grandchildren and five great-grandchildren.