Carl probably didn't have the foresight to trademark his name.
This reminds me of the trademark dispute over the name: "Taylor" as in "Taylor vineyards". One branch of the Taylors sold their vineyards & thus the use of their name. The New York Taylor branch did not. Yet they were forbidden to use their name on their wine labels. Bully Hill Vineyards, NY spent many years attempting to put their own family name on their own wine, and repeatedly lost. But they were not forbidden to use their address, which was "Greyton H. Taylor Memorial Drive" on the same label.