Disclaimer: The case studies we present on our web pages are based on court decisions which are all publically available. In case we add other publicly available information we usually will indicate the source of this information. Very often the original court decisions deal with various separate juridical problems at a time. As our intention is to use these case studies to segregate and accentuate a specific problem we usually keep our case studies focused to a selected problem. For sake of clarity we take the liberty of simplifying facts and patent claims or omitting ancillary information which have no legal relevance for the message we want to convey. In the event the numbers of the laws have been changed due to change of law, we refer to the up-to date numbers and not to the numbers that were valid at the time of the decision.





The Applicant filed an International Patent Application based on the priority of a German utility model relating to an apparatus for generating an aerosol. The aerosol is produced in a spraying chamber (medication chamber) and is conveyed to the patient through a breathing hose. Preferably the aerosol should be applied to the patient at a certain temperature. While passing through the hose the aerosol may cool off. The prior art therefore proposed to arrange heating wires in the breathing hose. The inventor recognized that the heating wires of the prior art were not-insulated and thus caused a hygienic problem. In order to overcome this problem the invention proposed that the heating wires are arranged inside the spirals of the breathing hose or form the breathing hose (feature D in the claim chart below).

The original filed utility model comprised in the independent claim only features A, B, C, and D of the claim chart below. A German utility model will be registered without an examination of novelty and inventive step, when the formal requirements are met. The examination of the formal requirements is a quick procedure, and the utility model was registered very little more than 4 months after the filing date.

Before the end of the priority year the plaintiff filed a International patent application, claiming priority of the German utility model. The independent claim comprised the same features A, B, C, D as the utility model. After receiving the International Search, which listed two documents of the category "X", the Applicant added feature E to his claim 1 and adopted the object of the invention to the newly added feature.


Object 1: 
Providing an improved breathing hose in order to avoid condensation and to ensure a homogeneous heating of the aerosol without exposing the aerosol to direct contact with the heating wires.
Solution 1 (Feature D):
the at least one heating wire is arranged inside the spirals of the breathing hose or forms the breathing hose
Object 2:
Avoiding deviations of the predetermined temperature.
Solution 2 (Feature F):
an acoustical and/or optical signalling device is provided for alerting that the temperature of the aerosol leaving the breathing hose, measured at the outlet of the breathing hose is deviating from a predetermined temperature.




Features chart EP 0 214 976

An apparatus for generating an aerosol

AThe apparatus comprises a flexible spiral breathing hose
BAn aerosol is produced in a medication chamber and is conveyed to the patient via the breathing hose
CAt least one heating wire is arranged in the breathing wire for heating the produced aerosol
Dthe at least one heating wire is arranged inside the spirals of the breathing hose or forms the breathing hose
Ean acoustical and/or optical signalling device is provided for alerting that the temperature of the aerosol leaving the breathing hose, measured at the outlet of the breathing hose is deviating from a predetermined temperature


A competitor was selling breathing hoses as auxiliary parts which incorporated the features C and D. The proprietor of the utility model started legal action against the competitor. As the hose with features C and D was part of the registered claim the hose had to be considered as an essential element of the protected invention. The court of first instance had no other chance than to recognize a contributory infringement.

The competitor appealed the decision and while waiting for the hearing was successful in cancelling the utility modell to an extend that the defendant was no longer infringing the utility model.

In the meantime the patent proprietor had pursuit his International application as a European patent application and had amended his main claim to include feature E. He also requested at the EPO an accelerated processing as he needed a patent to suit potential patent infringers. As the applicant had also adapted accordingly the description the EPO granted a patent without any objections. The plaintiff modified the basis for his infringement law suit in the appeal to the EP patent that was validated in Germany.

The court of second instance, the appeal court denied a contributory infringement as the breathing hose that was sold by the defendant did not comprise feature E and dismissed the claim.

The Litigant lodged a revision of the appeal at the Federal Court of Justice (Bundesgerichtshof – BGH) to review the points of law. This decision is particularly interesting as it was the first infringement case where the Federal Court of Justice had to apply Article 69 (1) of the European Patent Convention on a so-called partial combination (“Teilkombination”), i.e. where an alleged infringing subject matter does not fulfill all features of the patent claim, but only a part of the claimed features.

The plaintiff tried to argue that feature E was moved from a sub claim to the main claim and therefore a third party would have been aware, that feature E is of less importance than feature D. In summary the Federal Court of Justice ruled: “In the event the significance of a feature of the claims has been specifically emphasized in the patent specification an extension of the scope of a patent to a subject matter where the specifically emphasized feature is absent would constitute a breach of the legal certainty for third parties, as the Protocol of Article 69 (1) EPC expressively addresses the legal certainty for third parties.”

Final Remarks

In order to get awarded a contributory infringement the plaintiff should have had at least argued that the hose with features C and D is suitable or is intended to be used with a device with features A, B and E. In the contrary, during appeal proceedings at the Court of second instance, the plaintiff used as an argument, that feature E is not an essential feature of the invention, and therefore should be disregarded, because his competitors are successfully marketing devices without feature E and even the plaintiff himself so far did not make use of feature E.