The Chamberlain Group, Inc. (CGI), a leader in garage door opener and access control solutions, filed a patent infringement lawsuit against Nortek Security & Control LLC (NSC) on Thursday, November 30, 2017. Lawsuit Alleges Infringement on Three Patents for Inventions that Improve Safety and Energy Efficient Operation of Garage Doors and Gates; Patented Technology Used in Chamberlain® and LiftMaster® Brands