In its recently published decision, “Trommeleinheit,” the German Federal Supreme Court clarified its case law when replacing spare and wear parts in patent protected devices amounts to patent infringement. Manufacturers of patented printers have previously raised the issue in front of courts. They argued that using printer cartridges of other manufacturers in “their” printers infringes their patents on the printers. Prior cases have been fought very hard over this issue of high commercial importance, because, in many industries, manufacturers make more profit from the sale of spare and wear parts (e.g., printer cartridges) than from the sale of the original device (e.g., printer).

According to settled German law, a (somewhat artificial) distinction between a mere repair of the patented device and a so-called “new manufacturing” of the same has to be drawn in order to decide whether replacing spare and wear parts in the device infringes patents covering the device. In its earlier decision “Palettenbehälter II” (X ZR 97/11), the Federal Supreme Court had stated that a replacement of spare and wear parts amounts to patent infringement if the prevailing perception of the customers is that the replacement is more than a mere act of “repair,” which preserves the identity of the product as a tradeable good. The Federal Supreme Court, in the instant case, clarified that standard.

In its current decision, the German Federal Supreme Court stated that for cases in which the spare and wear parts are not traded as a distinct product, a “fictive consumer perception” based on normative factors shall not be applied for deciding the repair vs. “new manufacturing” question. The Federal Supreme Court thereby overruled the Higher Regional Court Düsseldorf.

The Court explained that an infringing “new manufacturing” only occurs if the spare and wear parts provide the technical (or economical) advantages of the patented invention. Under this clarified standard, it would not be an infringing “new manufacture” if the spare and wear parts only interact with other parts that actually achieve the advantages materialized within the patent. This decision is likely to limit the patent holders’ prospects of success in comparable situations, as it appears to have established a higher burden of proving infringement based on a “new manufacturing.” The mere act of exchanging certain spare and wear parts will now be less likely to amount to patent infringement – even if they are mentioned in the patent claim.