Liu Shen has achieved a favorable outcome defending a world leading manufacturer of inflatable sports goods against patent infringement allegations. Following our robust non infringement defense coupled with counter measures, the plaintiff ultimately withdrew its complaint, bringing the matter to a close. This removes barriers for our client to compete fairly within this niche product segment.

The dispute concerns inflation deflation valve technology utilized in vehicle mounted inflatable mattresses. Throughout the proceedings, the core contention centered on whether the accused technical solution constituted infringement under the doctrine of equivalents.

Against the plaintiff's assertions, the Liu Shen team delivered comprehensive arguments addressing the constituent elements for finding equivalent infringement and the foreseeability principle. In addition, the team conducted an in depth review of the prosecution history of the asserted patent. It was uncovered that during an earlier invalidation proceeding, the patentee had sought to further limit its claims in an attempt to expand protection scope so as to cover the accused technical solution. Such amendments were rejected by the panel on the ground that they went beyond the scope disclosed in the original specification and claims. Building upon this finding, our team submitted that technical subject matter outside the original patent disclosure ought not to be retroactively afforded protection via the doctrine of equivalents in infringement proceedings, further reinforcing our non infringement position.

Meanwhile, the team observed that the plaintiff added our key client as an additional defendant during the litigation, precisely while the client was participating in a procurement tender for relevant products. Moreover, following prior invalidation proceedings and notarized disassembly of the accused product, the plaintiff ought to have recognized the low likelihood of prevailing on its claims. On that basis, we advised our client to file a separate damage claim for malicious institution of intellectual property litigation, raising the legal risks that the plaintiff would face should it continue pursuing the instant action.

The plaintiff subsequently withdrew its complaint, concluding the case successfully.

This case underscores the critical value of synergizing patent infringement litigation, patent invalidation proceedings and damages actions for malicious IP litigation. By extracting key factual findings from prior invalidation records, the Liu Shen team converted such facts into solid grounds for non infringement arguments, while also establishing the factual foundation for a damage claim over abusive litigation. This holistic dispute resolution strategy proved effective in defusing litigation risks for the client, delivering strong support for the client's ongoing market expansion and preservation of competitive advantages.

The case was handled by YAO Guanyang and WANG Xiao.