Ratchet wheel 4 rotates intermittently about fixed axis A and is driven by pawl 7 which turns about axis C of lever 6. Lever 6 oscillates about fixed axis B. Keyed to the same shaft as wheel 4 is bevel gear 8 which meshes with bevel pinion 9. Bevel pinion 10 is rigidly attached to pinion 9 and meshes with bevel gear 11 which is keyed to shaft 3. Threaded shaft 3 is connected by a screw pair to carriage 1 which slides along shaft 13 and carries type wheel 2. Thus, by means of paper-feeding ratchet wheel 4 and a train of bevel gears, carriage 1 travels intermittently to the right. During this motion, spring 5 is wound up. When pawl 7 is withdrawn, spring 5 rotates shaft 3 in the opposite direction, returning carriage 1 to its initial position.
$2790$RG,FD$