Hmmmmmm... We have some conflicting info. Your link to Mr. Smartypants says the trademark was renewed in 1988. Trademarkia.com claims it lapsed in '93. Both cannot be right...right?
From Smartypants: The word "laundromat" was registered as a trademark by Westinghouse Electric, a subsidiary of White Consolidated Industries on Oct. 1, 1947. Westinghouse listed the word as first being used in commerce on Oct. 26, 1940, and renewed the trademark in 1988.