A copying apparatus capable of both-side printing comprises automatic feed means, copy medium transport means, change-over guide means shiftable between a first position for one-side printing and a second position for both-side printing, and copy medium stop means for stopping and holding the copy medium...http://www.google.com/patents/US3999852?utm_source=gb-gplus-sharePatent US3999852 - Copying apparatus capable of both-side printing
