Three-Blade Propeller Design Patent Not Infringed by Four-Blade Configuration

In Hartco Engineering, Inc. v. Wang's International, Inc., et al. (Fed. Cir., July 25, 2005, non-precedential) the court concluded that no reasonable jury could have concluded that the overall visual appearance of the claimed design (above, left) is substantially similar to the accused design (right):

"Comparing the two designs, we disagree with the district court that the
jury verdict of design patent infringement was supported by substantial
evidence. The designs do not have to be identical to an accused device to be
protected, see OddzOn, 122 F.3d at 1405, but Hartco’s patented design is limited
to the design it claimed with the three-blades and four circular features.
Appellants’ four-blade product has a substantially different overall ornamental
appearance from the claimed three-blade product. See Elmer, 67 F.3d at 1577-78.
As no reasonable jury could have concluded that the overall visual appearance of
the claimed design is substantially similar to the accused design, we do not
need to employ the point of novelty test. See KeyStone Retaining Wall Sys., 997
F.2d at 1451. We thus reverse the district court’s denial of judgment of noninfringement as a matter of law, together with the award of damages for design patent infringement."

Although this decision is not citable as precedent under Fed. Cir. R. 47.6, the also court noted that the inclusion of blades, a nose, and a tongue "are part of the general propeller concept and not protected ornamental aspects independent of their unique configuration." Instead, only the number and shape of the blades, as well as the four circular features, were ornamental aspects, subject to patent protection.