Abstract: A head with rotatable marking wheels indexable to select any one of a plurality of die symbols for marking a workpiece with a selected series of symbols. Each marking wheel is indexed by an associated cogwheel and a drive pawl which also prevents the marking wheel from overshooting the desired position when indexed. A centering pawl and the cogwheel also cooperate to yieldably center a die symbol in its desired position when its marking wheel is indexed and if it is shifted from such position by engagement with a workpiece.

Abstract: In a marking head having one or more marking wheels each rotated step-wise by a reciprocating actuating pawl engaged in successive circumferentially arranged recesses on the wheel and secured in marking position by a retainer pawl engaged under a spring bias successively in the recesses, improved structure wherein the recesses and retainer pawl have circumferentially spaced apart interengaged cam surfaces which permit circumferential shifting of the wheel induced by surface irregularities in a workpiece being marked and facilitate spring return of the wheel to centered position after the marking, each recess having a flat bottom engaged by a blunt flat end face of the actuating pawl, each recess having a flat rearwardly facing shoulder adjacent its forward cam surface engaged by a blunt forward face of the actuating pawl.