Confusion dogging best mode requirement in its waning days: Is intentional concealment required?

| June 5, 2013

Ateliers de la Haute-Garonne, and F2C2 Systems SAS v. Broetje Automation USA Inc. and Broetje Automation GMBH

May 21, 2013

Panel:  Newman, Prost, and Reyna.  Opinion by Newman. Dissent by Prost.


An embodiment with three grooves is disclosed in the specification of the patents-in-suit as a preferred embodiment of an apparatus for dispensing rivets.  In his deposition one of the two inventors stated that an odd number of grooves was required to prevent a rivet from rotating on itself in the device as a result of the rivet stem going inside one of the grooves.  The district court found that the specification did not “state that an odd number of grooves is better than an even number”, and concluded that the patents “effectively conceal the best mode.”  Summary judgment is granted.  On appeal the CAFC finds no violation of the best mode requirement. Questions:  Is the three-groove embodiment the best mode, or is the belief that an odd number of grooves is required the best mode?  Has the best mode been concealed, and does the concealment have to be intentional for the patent to be invalidated?


Plaintiffs Ateliers de la Haute-Garonne and F2C2 Systems SAS (collectively “AHG”) allege infringement by Broetje Automation USA Inc. and Broetje Automation GMBH (collectively “Broetje”) of two patents (US 5,011,339 and US 5,143,216), both entitled “Process for Distribution of Pieces such as Rivets, and Apparatus for carrying out the Process.”  The ‘216 patent issued from a division of the application which issued as the ‘339 patent, both patents claiming priority based on the same French patent application. Both patents relate to the “dispensing of identical pieces having a symmetry of revolution about an axis” (such as rivets) through a pressurized tube.  Claim 1 of the ‘339 patent, which is directed to a process for dispensing identical pieces, recites distributing a compressed fluid “through at least one longitudinal passageway (2b) on the internal surface of said tube and opening into the hollow center (2a) thereof.”   Claim 1 of the ‘216 patent, directed to an apparatus for orienting identical pieces, recites “at least one groove (2b).


Best mode

The main claims recite at least one longitudinal passageway or groove. The embodiment described as a preferred embodiment in the specification has three grooves, such as shown in Fig. 2 of the ‘339 patent.  The district court in essence was convinced by the defendants that the best mode is the belief that an odd number of grooves is required.  Consequently, the district court found that the disclosure of the three-groove embodiment shared (only) a trait in common with the best mode, and was insufficient to avoid summary judgment for failure to disclose the best mode.  The district court characterized the disclosure as being so “inadequate as to effectively conceal the best mode,” noting that “the clear weight of Federal Circuit authority holds that intentional concealment is not required for best mode violations….”

The CAFC majority opinion articulated the test for establishing best mode violation to be a showing that:

  1. The “inventor possessed a better mode” (at the time of the application filing) “than was described in the patent”; AND
  2. “[S]uch better mode was intentionally concealed.

Applying this test, the majority opinion compared:

  • the “general statement that an odd number is better than an even number” with
  • the three-groove embodiment described as a preferred embodiment in the application.

The majority concluded that the “general statement” does not represent a better mode than the disclosed three-prong embodiment. Thus, the first prong of the test for best mode violation was not met.  It was not even necessary to reach the second prong of the test, i.e., intentional concealment.  However, the majority opinion went on to say that there “was  no evidence of intentional concealment of a better  mode than was disclosed.”  This underscores a niggling issue that will probably never be resolved, i.e., is intentional concealment required to prove best mode violation?  The case law is sufficiently complex and divergent for proponents on each side of the issue to find support for their position, to wit the dissenting opinion by Judge Prost and the resort to footnotes in the majority opinion to rebutt footnotes in the dissenting opinion on this point.

The judgment of invalidity on the ground of best mode violation court decision is reversed and the case remanded.


The defendants had argued that the ‘339 patent was abandoned by failure to pay the issue fee.  (A check was written to pay the issue fee timely, but did not clear for insufficient funds.  The district court found that there was no abandonment since the PTO issued the patent (after some undisclosed corrective action by the prosecuting attorney.)  The CAFC affirms the ruling that the ‘339 patent was not abandoned.


If you are going to present a best mode defense in infringement litigation (a defense available only for litigation commenced on or before September 16, 2011), be prepared to show that the best mode was intentionally concealed, because you don’t know who will be on your panel.  Since the best mode defense is being phased out by the AIA, it is unlikely that the dichotomy of views in the CAFC on this subject will be resolved en banc.

Patent At Issue #1

Patent At Issue #2

Full Opinion

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