US 4,789,256 AGranted

Ribbon cartridge for printing machines

AssigneeIng. C. Olivetti & C., S.p.A.

InventorsBoris Ukmar, Mario Trompetto

Life of this patent

Estimating the term…

Loading patent…

Abstract

The ribbon (17) has an external run between the type element (25) and platen of a daisy-wheel typewriter. This run stretches between terminal members (59) which protrude from side arms (33 and 34) of the cartridge casing (18) and are fixed to the distal ends of arms (39, 41) pivotally mounted in the casing (18) at pivot (52). The arms (39, 41) are biased downwardly by wire springs (67) to expose the typing line. Ribbon lift levers of the typewriter raise the arms simultaneously to position a selected one of three tracks on the ribbon at the level of the typing point and a single drive shaft provides for the advancement of the ribbon. The cartridge comprises a feed spool and a take-up spool for the ribbon, a drive roller and a pressure roller which nip the ribbon internally to the casing, a transmission mechanism having a series of pinions and gears for transmitting the drive motion from the drive shaft of the typewriter to the pressure roller and to the take-up spool of the cartridge. A gear of the transmission mechanism is coaxial with the tke-up spool and is connected with the take-up spool by means of a friction clutch, which permits a slip motion between the gear and the take-up spool.

Claims4

Dependent claims

A ribbon cartridge for a typewriter or other printing machine of the type having a single drive shaft, and in which the cartridge comprises a casing;

a ribbon;
a take-up spool for the ribbon;
a drive roller;
and a pressure roller, which can be coupled to the single drive shaft for the unidirectional advance movement of the ribbon, and transmission mechanism between one of said drive roller and pressure roller and the take-up spool, wherein said transmission mechanism comprises a toothed wheel and the take-up spool has a hub member coaxial with the toothed wheel, and a friction clutch between the hub member and the toothed wheel, wherein said toothed wheel comprises a sleeve which projects axially from the toothed wheel and two shoulders which are positioned in diametrically opposite relationship to the sleeve, wherein said hub member includes an internal seat which is guided on the sleeve, and an outside circular groove adjacent to the internal seat;
wherein said friction clutch comprises a resilient ring which is mounted between said two shoulders of said toothed wheel and is housed in the outside circular groove of said hub member, and
wherein said two shoulders cause the resilient ring to be put in traction and to assume an elongate shape provided with two sections which engage frictionally the outside circular groove of said hub member.

3 more elements

Dependencies are inferred from the claim text.