Despite the seemingly clear statutory language that the written description “shall set forth” the best mode contemplated for carrying out the invention, this apparently requires only that the inventor not take any steps to “conceal” the best mode. Thus, best mode can still satisfied if one skilled in the art would recognize it as a “well-known substitute” for the mechanisms explicitly disclosed. (Just another nail in the coffin for the best mode requirement, but probably a moot point going forward with the AIA taking the teeth out of best mode anyway.)
Background / Facts: The patent at issue is directed to mining equipment. During discovery, the inventor admitted that “press-fitting” was the preferred way to retain drive pins in the side plates in the invention of claim 2, despite the fact that only welding was discussed in the application as a means to do so. However, there was evidence from both parties that press-fitting as a substitute for welding was well-known to those of ordinary skill in the art.
Issue(s): Whether the failure to disclose the best mode of “press-fitting” for the retaining means invalidates claim 2 under 35 U.S.C. § 112.
Holding(s): No. To establish that a claim fails the best mode requirement, it must be shown that the inventor “concealed” the best mode of practicing his claimed invention from the public. Whether an inventor “concealed” the best mode of his invention from the public turns on whether “the inventor’s disclosure is adequate to enable one of ordinary skill in the art to practice the best mode of the invention.” Here, press-fitting cannot be said to have been concealed as the best mode for the drive pin retaining means because it was a well-known substitute for the disclosed welding techniques to those of ordinary skill in the art at the time of the invention. Thus, despite its omission from the written description, one of ordinary skill in the art would nevertheless have had “the requisite knowledge necessary to use press-fitting as the drive pin retaining means of claim 2.”