Dan has decades of experience in all phases of the intellectual property practice, particularly patent litigation.

Winning patent cases, Dan explains, is like aligning the tumblers of a lock. First is getting the science right. One cannot win with the theory that the moon is made of green cheese. The science must then be coordinated with a sound legal theory than accounts for not only the most recent developments, but also venerable themes going back to Thomas Jefferson. All this must be presented in a way that is understandable by the judge and jury and appeals to their desire to reward the good guy and punish the bad guy.

Between college and law school, Dan had his first experience with legal matters as a Coast Guard office enforcing antipollution laws. Since being admitted to the bar, he has appeared in federal courts in California, Delaware, Florida, Illinois, Louisiana, Massachusetts, Missouri, New Jersey, New York, Ohio, Tennessee, Wisconsin, and the District of Columbia.

At Hahn Loeser

Dan has represented clients in diverse technologies, including automotive parts, chemical processes, computer hardware and software, explosives, farm equipment, food products, metallurgical coatings, office equipment, pharmaceuticals, and sporting goods. He devotes a large portion of his practice to representing generic pharmaceutical firms in Hatch-Waxman litigation. At Hahn Loeser, he feels privileged to be in a firm whose lawyers and staff have fun energetically providing top-notch representation of its clients.


Dan is active in the ManKind Project, an organization that helps men lead lives of integrity and service.

At home

Dan loves to travel with his wife, who is a professor of French literature and history, and so they go to France every few years. Other recent trips include Africa, Alaska, and the Galapagos Islands.

  • Olmesartan Medoxomil (Hypertension Drug), Apotex Inc. v. Daiichi Sankyo Inc., 781 F.3d 1356 (Fed. Cir. 2015) 
  • Risedronate (Osteoporosis Drug), Warner Chilcott Co. v. Teva Pham. USA, Inc., 2014 WL 6435042 (Fed. Cir.)
  • Ibandronate (Osteoporosis Drug), Hoffman-La Roche Inc. v. Apotex Inc., 748 F.3d 1326 (Fed. Cir. 2014)
  • Hard disk drives, Minebea Co. v. Papst, 444 F. Supp.2d 68 (D.D.C. 2006)
  • Truck transmissions, Eaton Corp. v. Rockwell Int’l Corp., 323 F.3d 1332 (Fed. Cir. 2003)
  • Metallurgical coatings for jet engine parts, United Tech. Corp. v. Heico Corp., 60 F. Supp.2d 1306 (S.D. Fla. 1999)
  • Ink ribbon cassettes, Smith Corona Corp. v. Pelikan Inc., 784 F. Supp. 452 (M.D. Tenn. 1992), aff’d, 1993 WL 192516 (Fed. Cir.)
  • Explosives, Austin Powder Co. v. Atlas Powder Co., 593 F. Supp. 208 (D. Del. 1984)



Harvard Law School, J.D., cum laude, 1976


Massachusetts Institute of Technology, S.B., 1970

Memberships & Affiliations

American Bar Association: member


American Intellectual Property Law Association: member


Chicago Bar Association: member


Federal Circuit Bar Association: member


Illinois State Bar Association: member


Intellectual Property Law Association of Chicago: member

Bar Admissions

Illinois Bar


U.S. Patent and Trademark Office