Apparatus for driving dotting hammers of a matrix printer

Claim 1

The improvement in an apparatus for driving dotting hammers of a matrix printer including means for moving printing paper which advances through the printer adjacent the hammers in one direction as the hammers dot the paper which comprises: a. a plurality of electro-magnets mounted in parallel position on the printer along the printing paper in a direction normal to the direction of advancement of the paper and at one side of the printing paper; b. at the other side of the paper a standard reciprocally moveable to various positions along the printing paper in a direction normal to the direction of advancement of said printing paper and moveable adjacent the parallel position of the electro-magnets; and c. flexible elongate electro-magnetically attractable plates each having a dotting hammer mounted along the standard in spaced parallel relation to the electro-magnets and adjacent the printing paper, wherein the electro-magnets attract the plates towards the electro-magnets and thus cause the dotting hammers to dot the paper as the standard is moved to the said variable positions and wherein the spacing of the electro-magnets mounted on the printer is one-half the spacing of the plates mounted on the standard, wherein there are twice as many electro-magnets as plates and wherein the electro-magnets are activatable alternately depending upon the position of the standard so that magnetic lines of force from an activated electro-magnet are absorbed by an adjacent non-activated electro-magnet while the activated electro-magnet attracts a plate.