A shaft assembly including an elongated member having at least a portion which is hollow having an inside surface defining a shaft core is provided. The shaft assembly includes a rotatable, torque transmitting elongated member defining a portion thereof which is hollow having an inside surface and defining...http://www.google.com.au/patents/US6517440?utm_source=gb-gplus-sharePatent US6517440 - Plastic shafts with molded core and external feature
