Friday, November 9, 2012

K-Tec, Inc. v. Vita-Mix Corp - design patents as prior art

In our previous posts we discussed using design patents as prior art against utility patent applications, with the caveat that the drawings in design patents may not sufficiently disclose the structure or the function of all the elements in the claimed invention. In a recent case of K-Tec, Inc. v. Vita-Mix Corp., the Federal Circuit affirmed the finding that two design patents used in an obviousness analysis were non-analogous art to the utility patent claims and that the asserted claims were not proved invalid. 

K-TEC, a company that manufactures and sells commercial blending equipment, owns U.S. Patents 6,979,117 (“the ’117 patent”) and 7,281,842 (“the ’842 patent”), covering blending jars with specific geometries. The specific geometry is claimed as “a fifth truncated wall disposed between two of the four side walls” and is illustrated below. As a result of this geometry, a vortex is created when blending liquid inside the container moves away from a central axis and toward the truncated wall. The shifted vortex creates a flow pattern that causes the liquid to ascend the corner opposite the truncated wall and to descend at the truncated wall during blending.

The trial court granted K-TEC’s motion for summary judgment that the Vita-Mix container infringed the asserted claims and partially granted K-TEC’s motion that the asserted claims were not invalid. In the invalidity analysis, the trial court found that two prior art design patent references to pitchers, Hobbs (U.S. Design Patent 163,117) and Grimes (U.S. Design Patent 227,535) were non-analogous art. Both of the Hobbs and Grimes relate to ornamental designs for pitchers having a truncated wall that cuts off one corner of otherwise square-shapes. On appeal to the Federal Circuit, among other issues, Vita-Mix argued that the district court erred in granting summary judgment that Grimes and Hobbs are not analogous art.

The Federal Circuit explained that for the reference to be “analogous art,” the reference must satisfy one of the following conditions:
(1) the reference must be from the same field of endeavor; or
(2) the reference must be reasonably pertinent to the particular problem with which the inventor is involved.  A reference is reasonably pertinent if it, as a result of its subject matter, “logically would have commended itself to an inventor’s attention in considering his problem.” 

As stated in the specification of the asserted patents, there are four prior art problems that the invention solves: blender speed, safety, cavitation, and the blender’s ability to blend frozen ingredients. In addition, the inventor testified that he sought to create a blending jar that would reduce or prevent cavitation when blending frozen drinks.

Vita-mix argued under the second prong of the test, that the Grimes and Hobbs references were reasonably pertinent to the particular problem with which the inventor is involved. Vita-Mix also noted that during the USPTO reexamination of the ’117 patent, the Board held that both Hobbs and Grimes were analogous art. K-Tec argued that the ornamental designs of the Grimes and Hobbs pitchers “had no bearing on the inventor’s cavitation problem,” which was unique to blenders. K-Tec also noted that the size of the container was not a “problem” in the prior art.

The Federal Circuit agreed with the district court that the design patent references were non-analogous art, finding that Vita-Mix did not “explain any rational underpinning for [the inventor] to have consulted non-blending containers or food mixers in order to solve the problems he encountered in designing a new blending container.” The Federal Circuit also found that the Board’s decision that both Hobbs and Grimes were analogous art did “not raise a genuine issue of material fact,” because the Board’s opinion did not issue until well after the district court entered final judgment.

This case elucidates another caveat when design patents are used as prior art. The drawings in design patents are predisposed to be silent as to the particular problem the design patent was trying to solve and probably are entirely unhelpful in reciting a field of endeavor associated with the design. The lack of description in design patents may further limit a practitioner in arguing against obviousness rejections by an examiner during prosecution or in asserting an invalidity defense based on obviousness. For example, arguments that a design patent teaches away from the claimed subject matter or fails to establish that there is a teaching, suggestion, or motivation to combine multiple references would be very unlikely.

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