PURPOSE: To simplify the structure by providing the 2nd lever which engages a driving gear with a gear with a feed pawl by coupling the 1st lever changing the position of a feed gear and, at the same time, locks it at the operation position.

CONSTITUTION: An electromagnetic plunger 11 is excited momentarily, oscillatory lever 9 swivels counterclockwise, and consequently sliding lever 17 moves down to swing rotating shaft 14 clockwise, so that worm gear 16 will engage with backward moving gear 21. Then, gear 21 starts rotating counterclockwise and backward- moving pawl 21a comes off lock lever 19b, so that sliding lever 17 will be locked by lock lever 19a. At this time, reciprocating segmentally-toothed gear 23 also rotates counterclockwise and driving plate 26 for conversion moves down. During the period, forward moving gear 22 makes a half clockwise turn synchronizing with backward-moving gear 21 and at the limit position of the reciprocation of driving plate 26, forward moving pawl 229 reaches a position right in front of where it engages with feed gear 8.