X-ray machines, CAT scanners, NMR imagers, ultrasound, and mammography machines often have an imager mounted on a rotating arm. To keep imagers in place, engineers at Sepac Inc., Elmira, N.Y. (www.sepac.com) designed an are brake that is spring applied and electrically released. The lightweight brake works on any application that rotates 30[degrees] or less. The five-inch long brake weighs 1.1 1b and supplies 90 1b-ft of torque. For comparison, a 360[degrees] brake that produces 90 lb-ft would have a ...