MPEP 2133.03(c)
The "Invention"

Ninth Edition of the MPEP, Revision 07.2022, Last Revised in February 2023

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2133.03(c)    The "Invention" [R-07.2022]

[Editor Note: This MPEP section may be applicable to applications subject to examination under the first inventor to file (FITF) provisions of the AIA as set forth in 35 U.S.C. 100 (note). See MPEP § 2159 et seq. to determine whether an application is subject to examination under the FITF provisions, and MPEP § 2150 et seq. for examination of applications subject to those provisions. See MPEP § 2152.02(c) through (e) for a detailed discussion of the public use and on sale provisions of AIA 35 U.S.C. 102.]

Pre-AIA 35 U.S.C. 102 Conditions for patentability; novelty and loss of right to patent.

A person shall be entitled to a patent unless -


  • (b) the invention was…in public use or on sale in this country, more than one year prior to the date of the application for patent in the United States


(Emphasis added).


In Pfaff v. Wells Elecs., Inc., 525 U.S. 55, 66-68, 48 USPQ2d 1641, 1647 (1998), the Supreme Court enunciated a two-prong test for determining whether an invention was "on sale" within the meaning of pre-AIA 35 U.S.C. 102(b) even if it had not yet been reduced to practice. "[T]he on-sale bar applies when two conditions are satisfied before the critical date [more than one year before the effective filing date of the claimed invention]. First, the product must be the subject of a commercial offer for sale…. Second, the invention must be ready for patenting." Id. at 67, 119 S.Ct. at 311-12, 48 USPQ2d at 1646-47.

The Federal Circuit explained that the Supreme Court’s "ready for patenting" prong applies in the context of both the on sale and public use bars. Invitrogen Corp. v. Biocrest Manufacturing L.P., 424 F.3d 1374, 1379, 76 USPQ2d 1741, 1744 (Fed. Cir. 2005) ("A bar under [pre-AIA] section 102(b) arises where, before the critical date, the invention is in public use and ready for patenting."). "Ready for patenting," the second prong of the Pfaff test, "may be satisfied in at least two ways: by proof of reduction to practice before the critical date; or by proof that prior to the critical date the inventor had prepared drawings or other descriptions of the invention that were sufficiently specific to enable a person skilled in the art to practice the invention." Id. at 67, 199 S.Ct. at 311-12, 48 USPQ2d at 1647 (The patent was held invalid because the invention for a computer chip socket was "ready for patenting" when it was offered for sale more than one year prior to the application filing date. Even though the invention had not yet been reduced to practice, the manufacturer was able to produce the claimed computer chip sockets using the inventor’s detailed drawings and specifications, and those sockets contained all elements of invention claimed in the patent.). See also Weatherchem Corp. v. J.L. Clark Inc., 163 F.3d 1326, 1333, 49 USPQ2d 1001, 1006-07 (Fed. Cir. 1998) (The invention was held "ready for patenting" since the detailed drawings of plastic dispensing caps offered for sale "contained each limitation of the claims and were sufficiently specific to enable person skilled in art to practice the invention".).

If the invention had been actually reduced to practice before being sold or offered for sale more than 1 year before filing of the application, a patent will be barred. Vanmoor v. Wal-Mart Stores, Inc., 201 F.3d 1363, 1366-67, 53 USPQ2d 1377, 1379 (Fed. Cir. 2000) ("Here the pre-critical date sales were of completed cartridges made to specifications that remained unchanged to the present day, showing that any invention embodied in the accused cartridges was reduced to practice before the critical date. The Pfaff ready for patenting condition is also satisfied because the specification drawings, available prior to the critical date, were actually used to produce the accused cartridges."); In re Hamilton, 882 F.2d 1576, 1580, 11 USPQ2d 1890, 1893 (Fed. Cir. 1989). "If a product that is offered for sale inherently possesses each of the limitations of the claims, then the invention is on sale, whether or not the parties to the transaction recognize that the product possesses the claimed characteristics." Abbott Laboratories v. Geneva Pharmaceuticals, Inc., 182 F.3d 1315, 1319, 51 USPQ2d 1307, 1310 (Fed. Cir. 1999) (Claim for a particular anhydrous crystalline form of a pharmaceutical compound was held invalid under the on-sale bar of pre-AIA 35 U.S.C. 102(b), even though the parties to the U.S. sales of the foreign manufactured compound did not know the identity of the particular crystalline form.); STX LLC. v. Brine Inc., 211 F.3d 588, 591, 54 USPQ2d 1347, 1350 (Fed. Cir. 2000) (Claim for a lacrosse stick was held invalid under the on-sale bar despite the argument that it was not known at the time of sale whether the sticks possessed the recited "improved playing and handling characteristics." "Subjective qualities inherent in a product, such as ‘improved playing and handling’, cannot serve as an escape hatch to circumvent an on-sale bar."). Actual reduction to practice in the context of an on-sale bar issue usually requires testing under actual working conditions in such a way as to demonstrate the practical utility of an invention for its intended purpose beyond the probability of failure, unless by virtue of the very simplicity of an invention its practical operativeness is clear. Field v. Knowles, 183 F.2d 593, 601, 86 USPQ 373, 379 (CCPA 1950); Steinberg v. Seitz, 517 F.2d 1359, 1363, 186 USPQ 209, 212 (CCPA 1975).

The invention need not be ready for satisfactory commercial marketing for sale to bar a patent. Atlantic Thermoplastics Co. v. Faytex Corp., 970 F.2d 834, 836-37, 23 USPQ2d 1481, 1483 (Fed. Cir. 1992).


Affidavits or declarations submitted under 37 CFR 1.131 to swear behind a reference may constitute, among other things, an admission that an invention was "complete" more than 1 year before the filing of an application. See In re Foster, 343 F.2d 980, 987-88, 145 USPQ 166, 173 (CCPA 1965); Dart Indus. v. E.I. duPont de Nemours & Co., 489 F.2d 1359, 1365, 179 USPQ 392, 396 (7th Cir. 1973). Also see MPEP § 715.10.


A claimed process, which is a series of acts or steps, is not sold in the same sense as is a claimed product, device, or apparatus, which is a tangible item. "‘Know-how’ describing what the process consists of and how the process should be carried out may be sold in the sense that the buyer acquires knowledge of the process and obtains the freedom to carry it out pursuant to the terms of the transaction. However, such a transaction is not a ‘sale’ of the invention within the meaning of [pre-AIA] §102(b) because the process has not been carried out or performed as a result of the transaction." In re Kollar, 286 F.3d 1326, 1332, 62 USPQ2d 1425, 1429 (Fed. Cir. 2002). However, sale of a product made by the claimed process by the patentee or a licensee would constitute a sale of the process within the meaning of pre-AIA 35 U.S.C. 102(b). See id. at 1333, 62 USPQ2d at 1429; D.L. Auld Co. v. Chroma Graphics Corp., 714 F.2d 1144, 1147-48, 219 USPQ 13, 15-16 (Fed. Cir. 1983) (Even though the sale of a product made by a claimed method before the critical date did not reveal anything about the method to the public, the sale resulted in a "forfeiture" of any right to a patent to that method); W.L. Gore & Assocs., Inc. v. Garlock, Inc., 721 F.2d 1540, 1550, 220 USPQ 303, 310 (Fed. Cir. 1983). The application of pre-AIA 35 U.S.C. 102(b) would also be triggered by actually performing the claimed process itself for consideration. See Scaltech, Inc. v. Retec/Tetra, L.L.C., 269 F.3d 1321, 1328, 60 USPQ2d 1687, 1691(Fed. Cir. 2001) (Patent was held invalid under pre-AIA 35 U.S.C. 102(b) based on patentee’s offer to perform the claimed process for treating oil refinery waste more than one year before filing the patent application). Moreover, the sale of a device embodying a claimed process may trigger the on-sale bar. Minton v. National Ass’n. of Securities Dealers, Inc., 336 F.3d 1373, 1378, 67 USPQ2d 1614, 1618 (Fed. Cir. 2003) (finding a fully operational computer program implementing and thus embodying the claimed method to trigger the on-sale bar). However, the sale of a prior art device different from that disclosed in a patent that is asserted after the critical date to be capable of performing the claimed method is not an on-sale bar of the process. Poly-America LP v. GSE Lining Tech. Inc., 383 F.3d 1303, 1308-09, 72 USPQ2d 1685, 1688-89 (Fed. Cir. 2004) (stating that the transaction involving the sale of the prior art device did not involve a transaction of the claimed method but instead only a device different from that described in the patent for carrying out the claimed method, where the device was not used to practice the claimed method until well after the critical date, and where there was evidence that it was not even known whether the device could perform the claimed process).