I personally have never seen a Kennedy dollar coin before. But apparently they are so popular that this hospital vending machine recognizes them. You learn something new every day!
LOL. Even though I'm not a coffee drinker, I'd totally feed it a Kennedy and see whether it counts it. I'm betting that it would reject actual halves, but accept small dollar coins. If it accepted Kennedy halves and counted them as dollars, I'd see what happened when I punched the coin-return button. On the vending machine here, I can put in two or three quarters, hit coin-return, and get different quarters back. If it swapped halves for dollars -- well, I'd probably call and clue them in, rather than draining the machine, but it would be a bit of a temptation. I did have a bank try to sell me an envelope of Ikes as half dollars once. They ended up charging me for dollars, not halves, but I wouldn't be a bit surprised if they paid the depositor for halves instead. Large coins confuse many people, and reading what's printed on them is apparently hard.
LOL, we have a local Greasy Spoon that has great burgers and ice cream. They have a hand written sign up by the order counter... "Ice Cream, any flavor, 50cents a scoop. 1964 and before Half Dollars: 5 scoops!" I love it!
LOL.. Why doesn't your sick ( Hospital ) machine show half- dollars, the like of Barber, Kennedy or others ??