An impact line printer is provided with a character drum which has characters such as letters and numerals on the peripheral surface thereof and printing hammers in opposite to the character drum, wherein a printing paper is passed between the character drum and the printing hammers. The printer is further provided with a driven shaft on which is mounted frictional discs. Wheel members are provided, each of which is opposed to and normally spaced apart from each of the frictional discs. The wheel members are selectively brought into contact with the frictional discs to actuate selected printing hammers to effect printing on the printing paper. The printing hammers on normally biased for example by means of spring to keep away from the character drum.