"On-Sale" bar can stop
a patent being issued —
but what is a "sale"?
The "on-sale bar" is a limitation on the patentability of an invention under 35 U.S. Code § 102, which says:
A person shall be entitled to a patent unless—
(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention;