Abstract: An inked ribbon cartridge is removably mountable in a printing machine of the type comprising a support for the cartridge, two transport elements engageable with two spools, respectively, of the cartridge around which the ribbon is wound, two sensing elements for sensing the amount of the ribbon wound on the two spools, respectively, of the cartridge, a ribbon movement reversing mechanism controlled by the sensing elements for determining the direction of the rotation of the two shafts, and a control element for shifting the sensing elements from an operative position in which they sense the ribbon to an inoperative position in which they are disengaged from the spools.

Abstract: A selector system for a printing head for use in printing machines and the like for selecting a character to be printed from the printing head. The system comprises at least two actuatable code bars. The printing head is positioned with respect to a first coordinate by the use of a selector lever having a set of pivot elements thereon each defining a pivot axis about which the selection lever pivots a preselected amount. In response to the actuation of the code bars, the pivot element about which the selector lever pivots is selected by two stop members each pivotable in response to the actuation of one of the code bars and each engageable with one of two pivot elements, a third stop member engaged with a third pivot element and not pivoting in response to the actuation of any of the code bars and a fourth stop member engaged with a fourth pivot element and pivotable in response to the actuation of either of the two code bars.

Abstract: A keyboard for a typewriter, teleprinter, calculator and similar office machines comprises a series of keys, a series of setting elements selectable by the keys and a group of code bars. A setting spring moves a common setting member which positions the selected setting element on the trajectory of the code-bars. A bridge controls the code-bars and is positioned, through a cam, by a driven part of a starting clutch for a setting cycle. An intermediate member connects the common setting member with a releasing member of the starting clutch, and when the key is depressed, the intermediate member activates the starting clutch after a predetermined path of the setting member. A series of flexible laminae are flexed by the selected setting element and successively arrest temporarily the returning at rest of the selected setting element avoiding the beginning of a new setting cycle in the case a key is kept depressed.

Abstract: A selector system for a type-bearing element of a typewriter, accounting machine or other office machines, wherein a positioning member for the type-bearing element is positioned positively by a series of cam followers movable by a corresponding series of cyclically actuated cams and controlled by selectively settable stop elements. The type-bearing element comprise a shell on which the types are distributed in rows and columns. The shell is rotatable on a support sleeve provided with two side walls external to the shell. The types are distributed in two groups selectable by a transport mechanism connected to the type-bearing element through differential gears controlled by a bistable spring and two stop elements.