Rights of third parties prior to application.
Section 40
SEC. 40. Rights of third parties prior to application.—any person who has purchased or acquired by the inventor, his legal representatives, or assigns, or who, with their knowledge and consent, constructs any newly invented device or other patentable article, prior to the filing of the application therefor, shall have the right to use and sell the specific thing purchased, acquired or made, without liability therefor.