Printer device

A printer device comprising:

• a type drum provided on an outer periphery thereof with a plurality of types;
• a plurality of hammers provided in the axial direction of said type drum and having one end in opposed relations to the types of said type drum and an other end provided with at least two engaging notches of a depth which are different from each other;
• hammer springs for biasing said hammers in directions of flying to said types, respectively;
• a reset cam for moving said plurality of hammers to a first retracted position against biasing forces of hammer springs;
• hammer holding members for being engageable with said engaging notches of said hammers, respectively, and for holding each of said hammers at the first retracted position when engaging with one engaging notch and at a second retracted position when engaging with the other engaging notch, each of said hammer holding members being formed in a bifurcated shape including two arms, and an outer side of one arm of which is engageable with and disengagable from said two engaging notches of said hammer to alternately hold said hammer at the retracted position and to release said hammer;
• and
• a plurality of electromagnetic means, each one of which is provided for at least two of said hammer holding members for selectively actuating said hammer holding members and selectively releasing said hammers, said electromagnetic means including an armature disposed to be movable between said two arms of said hammer holding member, said armature being movable between a first position engaging an inner side of said one arm when the electromagnetic means is not excited, and a second position engaging the other of said two arms when said electromagnetic means is excited for selectively releasing said hammers, wherein, in said first position, the inner side of said one arm acts as a stopper for said armature so ad to define a pre-stroke gap between said armature and said hammer holding members;
• wherein said pre-stroke gap is a predetermined value between the other of said two arms of said hammer holding members and said armature at the time of non-excitation and said armature moves within the pre-stroke gap during excitation of said electromagnetic means such that said armature is given sufficient speed to strongly push the other arm by inertial force thereof, and disengage said one arm from said one of said two engaging notches;
• whereby said hammer holding members can be readily disengaged from the one of said two engaging notches of the hammer.