Patent GB-989670-A (GB)
Title: Type carrier for high speed printing mechanism
IPC: B41J1/32
Filed: 1963-08-13
Abstract: 989,670. Selective printers; irik-ribbon mechanism. SPERRY RAND CORPORATION. Aug. 13, 1963 [Aug. 21, 1962], No. 31937/63. Heading B6F. In a high speed printer a continuously rotating type carrier 10, Fig. 1, having a plurality of type faces 20, Fig. 5, the type faces are fashioned in such a manner that portions 46 or 47, Fig. 7, which are oriented parallel or diagonally to the carrier arms are thinner than portion 45 oriented perpendicularly to the axis of said carrier, whereby the extent of smear imprints 46s or 47s in the character image will cause the resultant parallel or diagonally oriented portions of the reproduced character image to be wider than the respective parallel or diagonally oriented portions of the corresponding type face 20 and more nearly uniform in width with the perpendicularly oriented portions of the said character image. Type - wheel machines; hammer - impression arrangements.-The high speed printer comprises a type carrier 10, Fig. 1, in the form of a drum keyed to a continuously rotating shaft 11 to present type faces 20, Fig. 5, into registration with type hammers 12. The type hammers are driven by electromagnetic actuators each of which includes a coil 21 and pivotally mounted armature 22, having one arm which engages the shank of the type hammer to cause it to move into a printing operation. Ink-ribbon mechanism.-A transfer web 15 which may include duplicating sheets, Fig. 1, is drawn around guide rollers 16 by any suitable feeding mechanism (not shown) and is maintained out of contact with the type drum 10, except at the printing station, by arcuate shields 17 mounted in close proximity to the drum's face on each side of the printing station. Types, discs and printing surfaces.-The character type faces 20, Fig. 5, are arranged about the periphery of the type drum 10 and a series of rows and columns with each column, which runs perpendicularly to the longitudinal axis of the drum containing a full complement of alpha-numerical characters and special marks. The columns are arranged in alternately offset relationship in a checkerboard array so that identical characters occupy two adjacent rows extending in a direction parallel to the drum axis. Associated with each row of characters is a raised bar-like structure 23 formed on the drum surface used for registration of each row of type faces with the type hammer spring time control means. To compensate for the smearing effect of the printed image of a type character which extends parallel to the direction of the type carrier rotation and which depends on the time of contact of the type character with the printing medium and also on the effective contact area of the type face of the character each character type face is so fashioned, e.g. the numeral 1 in Fig. 7, that the portions 46 or 47, which are orientated parallel or diagonally to the carrier longitudinal axis are thinner than the portion 45 orientated perpendicularly to the axis of the type carrier, to compensate for the amount of smearing and provide the perpendicularly orientated portions 45i of the printed character image with the same width or boldness as the resultant printed character image portions 46i . . . 46s, 47i . . . 47s, which are parallel or diagonally orientated. Since the amount of smear depends on the effective area of the type faces 20, Fig. 5, and to secure a uniform height of the characters the type faces such as " L " are slightly smaller than the type faces such as " M," which have a larger effective contact area. In addition, to align all character images with respect to the base of the printed line the characters are offset by a distance I from a reference line passing through the bar structures 23. The distance I is proportional to the effective contact area of the type faces 20. In another embodiment (not shown) the characters in a column may be spaced uniformly and the bar structures 23 spaced as determined by the requisite distances 1.