It gave the partners an idea. They hired two former Westinghouse engineers, Edmund Abel and Erwin Schulze, to create a compact, stylish version of the commercial dispenser. Their effort led to Mr. Coffee, in which water enters an electric heating element at the top, then trickles into the coffee grounds in a disposable paper filter before emptying into a glass pot resting on another heating element to keep it warm. To avoid the bitterness that boiling can cause, it heats the brew to only about 200 degrees.Introduced in 1972, Mr. Coffee caught on quickly. The parent company, North American Systems, sold more than a million units within three years. Although more established appliance manufacturers created their own versions, Mr. Coffee would gain and hold approximately 50 percent of the market share into the late 1970s.Good friends since high school, the two men had been partners in a series of businesses for more than 20 years, particularly real estate development, when they bought a coffee delivery company serving the Cleveland area in the late 1960s. On the delivery trucks were bulky, stainless steel commercial coffee dispensers. ''Can we get one of these for the house?'' customers would ask, Mr. Glazer's son, Robert, said in an interview.