To improve tracking, an exercise treadmill is provided with a frame including molded plastic pulleys, having an integral gear belt sprocket, an endless belt extending around the pulleys and a motor operatively connected to the rear pulley to drive the belt. The pulleys are molded out of plastic and have...http://www.google.com/patents/US6095951?utm_source=gb-gplus-sharePatent US6095951 - Exercise treadmill
