United States Federal Circuit

In a patent dispute involving a magnetically coupled piston, a judgment of non-infringement in favor of defendant is affirmed as: 1) foreseeability does not require an applicant to be aware that a particular equivalent would satisfy the insubstantial differences test or the function/way/result test with respect to the claim as amended; 2) an alternative is foreseeable if it is disclosed in the pertinent prior art in the field of the invention, or, in other words, an alternative is foreseeable if it is known in the field of the invention as reflected in the claim scope before amendment; and 3) defendants' aluminum sleeve was a foreseeable alternative to plaintiff's magnetizable sleeve, and prosecution history estoppel applies.

Appellate Information

• Decided 07/05/2007
• Published 07/05/2007

Judges

• Before MICHEL, Chief Judge, NEWMAN, and DYK, Circuit Judges.

Court

• United States Federal Circuit

Counsel

• For Appellant:
  
• Charles R. Hoffmann, Hoffmann & Baron, LLP, of Syosset, NY, argued for plaintiff-appellant.   With him on the brief were Glenn T. Henneberger and Anthony E. Bennett.


• For Appellees:
  
• Arthur I. Neustadt, Oblon, Spivak, McClelland, Maier & Neustadt, P.C., of Alexandria, VA, argued for defendants-appellees.   Of counsel on the brief was James B. Lampert, Wilmer, Cutler, Pickering, Hale and Dorr LLP, of Boston, Massachusetts.