Abstract: A printing device in which a roll having a plurality of characters disposed thereon is displaceable with respect to at least one printing hammer. The printing hammer cooperates with a coil which, when excited, generates a field which by cooperation with a stationary field, puts the hammer into motion and drives it against the character on the roll to be printed. The hammer is arranged to be movable in the device so that the distance between the hammer and the roll is adjustable. A control device is provided which measures the hammer flying time and compares this time with a nominal flying time and which, in the case of a difference, displaces the hammer relative to the roll and also changes the driving force of the hammer.

Abstract: A device for printing data on a paper chart which is provided on both sides with a perforation track. The device comprises at least one pair of tractors, one of which engages in the one perforation track while the other engages in the other perforation track so as to transport the paper chart along the printing location. The device furthermore comprises a paper guide for guiding the paper after its departure from the tractors. A paper drawing device is arranged substantially at the end of the guide and is coupled to the drive system for the tractor pair by way of an elastic transmission.