Print hammer arrangement in dot line printer minimizing number of hammers simultaneously fired

A dot line printer comprising:

• a hammer bank, said hammer bank comprising a plurality of print hammers, each having a print pin;
• means for moving said hammer bank back and forth in a shuttling direction;
• holding means for holding said plurality of print hammers in non-printing positions with magnetic attractive force;
• a plurality of electromagnetic coils provided in one-to-one correspondence to said plurality of print hammers;
• means for supplying a current of a predetermined duration to each of said plurality of electromagnetic coils thereby creating a magnetic field which counteracts the magnetic attractive force produced by said holding means thereby releasing the print hammers from their non-printing positions for making dot impressions on a sheet of print paper;
• and
• means for moving said sheet in a line to line direction,
• wherein said plurality of print hammers of said hammer bank are divided into a plurality of groups so that each group includes N-number print hammers where N is an integer equal to or greater than 3, said N-number print hammers in each group being displaced by a distance corresponding to one dot line in the line to line direction so that L dot lines are printed with each of forward and backward movements of said hammer bank where L is an integer equal to or greater than 3, and wherein said printer further comprises;
• means for releasing said N-number print hammers, in each of said groups, in a predetermined successive order, so that only 1/N of said plurality of print hammers are fired simultaneously, and wherein positions of (N-1) print hammers in each group are displaced in the shuttling direction from respective home positions by (n-1)/N.multidot.D), where n is a number indicative of an order in which one of said (N-1) print hammers is released, n being an integer in a range of from 2 to N, and D represents a number of dots printable per unit length, as measured in the shuttling direction, to compensate for the successive releasing of the print hammers, said home positions being imaginary positions of said print hammers spaced equidistant from one another, by a predetermined distance.