GB1025511A - Printing hammer - Google Patents

Abstract

1,025,511. Printing hammers. SVENSKA DATAREGISTER A.B. Jan. 30, 1963 [Feb. 21, 1962], No. 3810/63. Heading B6F. In printing apparatus for cash-registers &c. comprising type wheels 40, Fig. 1 (not shown), coacting with hammers 10 for printing characters in code, e.g. for subsequent photo-electric scanning, each hammer has slots 38, 42 dividing its end into separate surfaces 44a, 44b, 44c which spring relatively to one another as impact is made with its typewheel and thus come into proper contact with a group of code characters 30a-30c on the wheel and representing a numeral. The inner ends of the slots may be circular as shown at 50 to increase the springing effect. A number of side-by-side hammers may coact with each type-wheel, Fig. 4 (not shown), and a pin 48, Fig. 2 (not shown), engaging enlargements in the slots 42 is provided to limit the movement of the hammers when the code characters do not cover the full width of a wheel. Hammer action.-The hammers 10 are carried by a bracket 20, Fig. 1 (not shown), pivoted on a fixed shaft 12 and having a recess 26 engaged by a pawl 28 to hold the hammers in inoperative position. An arm 14 also pivoted on the shaft 12 is connected to the bracket 20 by a spring 16 and has a pin 24 movable in the recess 26. When the pawl 28 is lifted to release the bracket 20, a spring 46 impels the bracket 20 and arm 14 clockwise to effect printing. The movement of the arm 14 is stopped by a pin 36 before the hammer makes impact and the movement of the bracket 20 is then limited by the pin 24. Resetting of the hammers is effected by turning the arm 14 anticlockwise until the pawl 28 re-engages the recess 26.