The Ringling Family Crest
The family's name was historically "Rüngeling". It was father August's last name (born in Hannover, Germany) and also his father Frederich's last name (born in Dankelhousen). Those cities are in a region called Westphalia.
However, when the 5 brothers started to perform in Baraboo, Wisconsin, the local newspapers misspelled their name and called them the Ringling Brothers. After this they adopted that easier to pronounce and to spell name.
Source: Great American Mansions, Merrill Folsom.
In German spelling it is difficult to do an umlaut (the two dots) on top of a capital (upper case) letter. In those cases they put an e behind the capital letter instead of the unlaut on top. Therefore Rüngeling all in upper case letters is always spelled RUENGELING.