Owen J. Roberts

“ None of the statutes has ever embodied as an element the place of invention or discovery, but the change effected by the Act of 1836, and carried forward in all succeeding statutes, is the fixation of the actual date of the inventive act as the date prior to which the invention must have been known or used to justify denial of a patent for want of novelty. ”

“ Decisions turning on prior public use have been numerous both in this court and in other federal courts; and the definition of such use, formulated when the statute made only use by consent a bar, has been adopted in instances where the use was without consent or knowledge of the applicant for patent. [32]
A mere experimental use is not the public use defined by the Act, [33] but a single use for profit, not purposely hidden, is such. [34] The ordinary use of a machine or the practise of a process in a factory in the usual course of producing articles for commercial purposes is a public use. ”

“ In the circumstances we think we are not justified in assigning to the findings below the force of a finding that Shimadzu, with intent, concealed his invention and delayed making applications for the purpose of unduly extending the life of his patents,-a defense not pleaded.
Third. If a valid patent is to issue, the invention must not have been in public use in this country for more than two years prior to the filing of the application. [27] Such public use is an affirmative defense to be pleaded and proved. ”