Printer with validation paper feeding mechanism

A printer with a validation paper feeding mechanism, comprising:

• a rotatable shaft continuously driven in a direction of feeding a validation paper;
• a friction roller rotatably supported and extending parallel to said rotatable shaft;
• a validation paper feed roller mounted on said rotatable shaft for feeding the validation paper in cooperation with said friction roller, said validation roller having an arcuate circumferential surface for pressing the validation paper against said friction roller, and a chord flat surface apart from said friction roller when said validation roller is located at a predetermined rotational position;
• a ratchet wheel mounted on said rotatable shaft, said ratchet wheel having a positioning projection for determining an initial position of said validation roller, and a plurality of pawls for stopping said validation roller at a plurality of predetermined positions;
• a one-way clutch disposed between said rotatable shaft, said validation roller and said ratchet wheel for transmitting a torque of said rotatable shaft to said validation roller only in the direction of feeding the validation paper;
• an armature disposed in confronting relationship with said ratchet wheel and having an engage portion, said armature supported swingably between a first angular position in which said engage portion engages with said pawls and a second position in which said engage portion engages with said positioning projection;
• means for urging said engage portion of said armature to said first angular position;
• and
• means for angularly moving said engage portion of said armature to said second angular position;
• said locking portion of said armature being disengaged with said positioning projection when said engage portion is positioned in said first angular position.