BGH Decision on Motivation of Inventive Step

BGH X ZR 19/21 "Vacuum Cleaner"

In BGH X ZR 19/21 "Vacuum Cleaner," the patent in dispute concerned a vacuum cleaner with a partition wall between a particle collection chamber and a blower chamber, featuring an air guide funnel and an interference protection element. Document D25, submitted during European opposition proceedings, disclosed all these features. The applicant then limited the claim to specify that the partition wall, air guide funnel, and interference protection element were formed as a single piece.

 In T 0621/15, the EPO Board of Appeal affirmed inventive step, arguing that the geometry of D25's intake grille (interference protection element) contradicted single-piece manufacture by injection molding.

 The defendant in the infringement case then filed a nullity action against the German part of the European patent before the Federal Patent Court, which revoked the patent. The court reasoned that a skilled person could, as part of routine considerations for single-piece construction, modify D25's intake grille geometry to allow for unproblematic injection molding in one step.

 The patent owner appealed to the Federal Court of Justice (BGH), which overturned the Federal Patent Court's decision. The BGH stated that D25 primarily focused on the functional design of the intake grille to ensure optimal airflow. Thus, the skilled person would need a motivation to deviate from this core idea and modify the proposed shape for manufacturing methods. Such motivation was necessary even if single-piece manufacturing was a general means within the skilled person's reach. The BGH saw no such motivation based on D25.Therefore, starting from a prior art document where multiple functionally interacting elements of a device are designed in a way that makes single-piece construction difficult at best, a single-piece design is not obvious merely because it is possible for the skilled person to alter the shape and orientation of these elements to allow for easy one-step injection molding.

In contrast, in BGH X ZR 49/21 "Dental Camera," the BGH ruled that while replacing a component of a dental camera with a newer component generally requires motivation, such motivation exists and inventive step should be denied if the newer component clearly fulfills all essential functions of a comparable component in a known device, and no fundamental difficulties or interactions are apparent that would prevent such a replacement. 

Article by Tobias Ernst, Patent Attorney at HKW Intellectual Property.