Engineer Fairchild Camera and Instrument Corporation, Clifton, New Jersey, 1960-1966. Associate Davis Hoxie Faithfull and Hapgood, LLP, New York City, 1966-1971. Partner Davis Hoxie Faithfull and Hapgood, 1972-1995.
Principal Fish & Richardson Professional Corporation, 1995—2002, senior counsel, 2003—2008, senior principal, since 2008. Member intellectual property litigation advisory committee United States District Court for the District Delaware, 1994-1996. Member neutral evaluation and mediation panels United States District Court for the Eastern District of New York, 1994-1997.
Member mediation panel United States District Court for the Southern District New York, 1994-1997.
Member European Practise Committee. Fellow American Bar Foundation (life), American Intellectual Property Law Association (chairman federal practice and procedure committee 1974-1976, chairman unauthorized practice committee 1977-1979, chairman trade secrets committee 1992-1994, member Japan practice committee since 1992, member editorial board Quarterly Journal, 1994-1995, chairman federal litigation committee 1995-1997, chairman international committee 1998-1900, board directors 2000-2003, member amicus committee 2003-2006, member special committee legislation strategies 2003-2005, member professional responsibility committee 2005-2008). Member Institute of Electrical and Electronics Engineers, American Bar Association (chairman antitrust law section committee on patents, trademarks and know how 1986-1989, member legal economics section, business law section, chairman intellectual property law division IV 1995-1996), American Physical Society (life), Federal Bar Council, Federal Circuit Bar Association, New York State Bar Association, Association Bar City of New York, New York Intellectual Property Law Association (secretary 1981-1984, director 1984-1986, president 1989-1990), United States Bar-European Patent Office Liaison Council (delegate since 2003, chair 2008-2010), Japan Patent Office Liaison Council (delegate since 1990), International Intellectual Property Society, International Patent and Trademark Association (United States group Association Internationale pour la Protection de la propriété Intellectuelle), International Trademark Association (board directors 1985-1987, finance committee 1987-1995, public committee 1997-1998).