409. Implied and limited licences.

409.     Implied and limited licences.

An article sold by the proprietor of a patent1 or his licensee2, or by one of the co-proprietors3, is presumed to be free of patent claims, giving the purchaser the right to use it as if there were no patent4. However, if at the time of sale5 the purchaser has notice of some restriction6, imposed by the proprietor or those representing him, that restriction will bind the purchaser7, although the court will not presume that the purchaser knew of the restriction merely because notice of it was marked upon the article, if