Wilson Sporting Goods and Hypothetical Patent Claims: A New Slice at the Doctrine of Equivalents

Document Type


Publication Date

Summer 1991


In Wilson Sporting Goods v. David Geoffry Assoc, the Court of Appeals for the Federal Circuit introduced a new test limiting the patent law doctrine of equivalents. This "hypothetical claim" test requires that the court compare the product accused of patent infringement with the prior art of the claimed invention in a manner similar to that it uses when determining the validity of patent claims. This paper analyzes the methodology of this new test and analyzes the appropriateness of a patentability-type test to the patent infringement context, and its potential effect on future infringement suits.