The Triple Bell belongs to the largest floor machines of the 40s
and is in fact a huge one-armed bandit. With the Triple Bell you can insert 1 up to 3 coins. One of 5, one of 10, and one of 25 dollar cents.
Suppose you insert three coins. You push the handle down, and the three reels with cherries, oranges, plums and other fruit symbols start to spin. Meanwhile, all sorts of lights flash on and off on the backglass, including those of the green, yellow and red scores. On the horizontal glass three large bells are lit. These show the number of coins you are playing. As the reels stop, it seems that you have won. Three oranges in a row.
Now you look at the backglass to see how much you have won. The first reel with fruit symbols and numbers goes with the 5 cents coin. Besides the three oranges you can see a green, yellow and red line with numbers. The yellow line is lit, and that means you get paid out 14 times 5 cents. On the middle reel (that goes with the 10 cents coin) the green line is lit, and that only brings in 10 times 10 cents. But, luckily for you, on the right reel the red line is lit. The red line always pays out the most. In this particular case, 30 times 25 cents.
The Triple Bell can be programmed to "pay out" as well as "free games".