Mills Novelty Company
was the worlds largest manufacturer of coin-operated machines. Their coin-operated machines spanned some sixty-four years starting back in 1889 until closing in 1953. Mills produced Coca-Cola's first stand-up dry vendor in 1935. You'll notice Mills machines were highly sophisticated in design and didn't require any manual operation such as a pull lever, crank handle, or knob to turn. Another note about Mills was they manufactured their own refrigeration units so the units used weren't of inferior design! Mills was unequalled in both design and workmanship.
Below is an excerpt that supresedes my comment on Mills closing the doors in 1953:
"In November 1955, Mills Industries, Inc. announced a coin-operated vending machine, developed jointly with H. J. Heinz Company, that would dispense a tin can of hot food (one of a selection of six soups or dinners), a can opener, and a spoon. The cans were maintained a constant temperature of 150 degrees Fahrenheit (65 °C). The machine was intended for use in factories or large offices, and the company claimed that it was a first of a kind in the United States."