September 2013

Prior Art’s Brief Teaching of Counter-Rotation Is Not Sufficient to Prove Anticipation or Obviousness
Bill Yu

Judges:  Rader (author), Reyna, Davis (sitting by designation)

[Appealed from W.D. Wis., Senior Judge Crabb]

In Cheese Systems, Inc. v. Tetra Pak Cheese & Powder Systems, Inc., Nos. 12-1463, -1501 (Fed. Cir. Aug. 6, 2013), the Federal Circuit affirmed the district court’s grant of SJ of infringement and validity.

U.S. Patent No. 5,985,347 (“the ’347 patent”) discloses a horizontal cheese-making vat.  Cheese-making vats are considered horizontal in the art when rotating agitator shafts are generally parallel to the ground.  Rotating shafts are typically mounted with two-sided agitator panels:  one side has relatively sharp cutting edges for cutting a semisolid mass called “coagulum,” and the other side has relatively blunt edges for stirring the coagulum.  The prior art teaches that the shafts should corotate such that only cutting or only stirring takes place in an overlapping common volume located between the shafts.  While contra- or counter-rotation would normally produce both cutting and stirring actions in the common volume, the invention of the ’347 patent rearranges the panels such that during contra-rotation, both panels perform only cutting or only stirring in the common volume.  Tetra Pak Cheese and Powder Systems, Inc. (“Tetra Pak”) is the exclusive licensee of the ’347 patent.  Cheese Systems, Inc. (“CSI”) owns a vat that includes counter-rotational shafts running generally horizontal to the ground, producing only cutting or only stirring actions. 

CSI sued Tetra Pak for DJ in the U.S. District Court for the Western District of Wisconsin, and pleaded that it did not infringe and that the asserted claims were invalid.  Tetra Pak filed a counterclaim, alleging that CSI’s vat infringed the ’347 patent.  The district court found that CSI’s vat infringed the ’347 patent, and that CSI had not proven the ’347 patent invalid.  Accordingly, the district court granted SJ of infringement and validity for Tetra Pak, and entered a permanent injunction against CSI.

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“Anticipation requires clear and convincing proof that a single prior art reference ‘not only disclose[s] all of the elements of the claim within the four corners of the document, but . . . also disclose[s] those elements arranged as in the claim.’”  Slip op. at 15 (alterations in original) (quoting Net MoneyIn, Inc. v. Verisign, Inc., 545 F.3d 1359, 1369 (Fed. Cir. 2008)).

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On appeal, the Federal Circuit reversed the district court’s denial of Tetra Pak’s motion for SJ of literal infringement with respect to the claimed term “generally common plane,” holding that the district court’s construction requiring the panel surfaces to be “on the whole flat” is too restrictive.  Rather, the Court held that this term should only “require the panel to have . . . more than two cutting and stirring edges [that] lie in respective generally common planes.”  Slip op. at 11.  Accordingly, the Court affirmed SJ on the ground of literal infringement, without reaching the alternative ground of the DOE, which was the basis of the district court’s decision, noting that this Court had discretion to affirm SJ on any ground shown by the record.

The Court also affirmed the district court’s grant of SJ on literal infringement with respect to the claim terms “agitator panel” and “horizontally disposed axes.”  The Court rejected CSI’s argument that “horizontal” requires the axes to be exactly parallel to the ground, holding that this term permits some degree of incline, as a person of ordinary skill in the art would understand.  The Court noted that even CSI’s own expert and patents described vats with slight inclines as horizontal. 

The Court also held that CSI failed to prove the ’347 patent invalid on the ground of anticipation or obviousness.  CSI relied on its own patents as prior art, which briefly mention that the agitators can be arranged for counter-rotation when demanded by specific production criteria.  The Court found that CSI’s patents make no further mention of counter-rotation, let alone suggest switching the orientation of the panels on one shaft so that only cutting or only stirring takes place in the common volume during
counter-rotation.  Accordingly, the Court held that CSI had not shown clear and unambiguous teaching for a compelling case of anticipation. 

The Court also affirmed the district court’s grant of SJ of nonobviousness.  The Court noted that although the district court did not expressly consider objective evidence, which would ordinarily require a remand, no remand was required in this case because CSI failed to prove obviousness.  The Court first rejected CSI’s argument that because contra-rotation was disclosed in the art, it would have been obvious to flip the orientation of the panels on one shaft.  The Court noted that although CSI’s own patents mention that the shafts can be arranged to contra-rotate, these patents fail to suggest switching the orientation of the panels, a means to mount the panels in the opposite direction, production criteria that might require counter-rotation, or the benefit of counter-rotation.  The Court then rejected CSI’s expert testimony aimed to fill the voids of its patents, explaining that the expert testimony stating that a person of ordinary skill in the art knew that cutting and stirring at the same time would damage the coagulum ignored the state of the prior art.  The Court further held that CSI’s initial expert report asserting that the drawings of a German language Austrian patent teach counter-rotation failed to present a clear and convincing case of obviousness, emphasizing the facts that CSI’s expert did not speak German and did not obtain a translation of the Austrian patent, but solely relied on the drawings, which are not self-explanatory, and that the patent actually describes corotation, not the counter-rotation alleged by the expert.  Moreover, the Court held that the district court correctly excluded CSI’s untimely filed supplemental expert declaration that was based on a partial translation of the Austrian patent, because permitting this supplemental report, which was offered two months after the discovery deadline and after Tetra Pak had filed its motion for SJ, would result in apparent prejudice.