The Patent and Trademark Resource Center at Minneapolis Central Library offers access to powerful search tools for researching patents and trademarks. Resources are available for Minnesota residents to help inventors and entrepreneurs learn more about protecting their intellectual property.First, the applicant for patent must be able to demonstrate that he or she has developed a new, useful, and not obvious process or product. Use the search tool below to find a USPTO location or PTRC near you. We suggest calling ahead of your visit for hours of operation, services, and fees. For most practical purposes, state registration of a trademark is meaningless. Find the best patents attorney serving Hennepin County. Find the best intellectual property attorney serving Hennepin County. Patent search tools. Search granted U.S. patents and published U.S. patent applications.