This question pertains to U.S. law, and California law specifically, if it matters.
The motivation behind this question is the scenario where a company has supplied parts or equipment usage to a non-employee inventor in exchange for a non-exclusive and revocable license, in the event that a patent should issue on the invention, or in the event that copyright matter is produced. Is this a valid contract? If not, can the company later claim an interest in the invention and copyright matter?
I think the central and key issue is whether a non-exclusive and revocable license constitutes consideration.