Can a single sale or offer to sell trigger the on-sale bar?
Yes, even a single sale or offer to sell can trigger the on-sale bar under 35 U.S.C. 102(b). The MPEP explicitly states:
Even a single sale or offer to sell the invention may bar patentability under pre-AIA 35 U.S.C. 102(b).
(MPEP 2133.03(b))
This principle is supported by case law, including Consolidated Fruit-Jar Co. v. Wright and Atlantic Thermoplastics Co. v. Faytex Corp. It’s important for inventors and patent applicants to be aware that even a single commercial transaction involving the invention can potentially bar patentability if it occurs more than one year before the patent application filing date.
To learn more:
Topics:
MPEP 2100 - Patentability,
MPEP 2133.03(B) - "On Sale",
Patent Law,
Patent Procedure