Horace Gray, Dable Grain Shovel Company v. Flint…
“ It is agreed that the machines in question were constructed and put in use in the defendants' grain elevators by the inventor himself, and with his knowledge and consent, while he was in their employment as superintendent of machinery, and before his application for either patent. According to the express terms of the statute, therefore, the defendants had the right to continue to use these specific machines without paying any compensation to him or his assigns, whether asked for or not. ”
