Printing devices

A printer for a tape which constitutes an elongated web, said printer comprising:

• A. tape transport means to advance the tape through a printing station at which the tape is movable in a plane in a direction parallel to the longitudinal axes of the tape,
• B. a single stationary anvil which has a narrow rectilinear edge and which is mounted at the printing station so that said edge lies adjacent and parallel to and to one side of said plane, the length of said edge of said anvil extending in a direction transverse to the direction of tape advancement;
• and
• C. a printer unit which is mounted at the printing station to lie on the opposite side of said plane to the anvil, said printer unit including:
• i. a plurality of elongated narrow planar metal strips each having an end portion that constitutes a printing element;
• ii. means to mount said strips to lie side-by-side in face-to-face contact in a stack, the dimension of which perpendicular to the planes of the strips extends in a direction parallel to the length of said rectilinear edge of said anvil for limited longitudinal sliding movement relative to one another and with said end portions thereof lying generally parallel to the direction of tape advancement and facing the rectilinear edge of said anvil,
• iii. a plurality of electromagnets forming a first group of electromagnets,
• iv. a plurality of further electromagnets forming a second group of electromagnets,
• v. means to mount said first and second groups of electromagnets so that the two groups are disposed on opposite sides of said stack of strips with the longitudinal axes of the electromagnets of both groups lying parallel to the lengths of said elongated strips, and
• vi. a plurality of armatures each having a projecting finger portion and each associated with a different one of said electromagnets of the first and second groups and with one of said strips, each armature lying with its finger portion adjacent the end of the associated strip remote from said end portion thereof so that upon energization of any one of the electromagnets during use of the printer unit, the attraction of the associated armature causes the finger portion of that armature to press against the end of the associated strip remote from said end portion and effect longitudinal movement of the associated strip towards said anvil to print a mark by cooperation of said end portion of that strip and said anvil and a character is printed by selective energization of said electromagnets of the first and second groups as the tape is advanced to cause a plurality of such marks to be printed each by cooperation of the end portion of the appropriate strip and said anvil;
• vii. all of said strips cooperating during advance of said tape to form a single character.