A ribbon feed device for preventing a feed gear-lock in an ink ribbon cartridge
Original Publication Date: 2005-Feb-01
Included in the Prior Art Database: 2005-Feb-01
Disclosed is a ribbon feed device for preventing a feed gear-lock in an ink ribbon cartridge such as for a dot matrix printer.
A ribbon feed device for preventing a feed gear -lock in an ink ribbon cartridge Disclosed is a ribbon feed device for preventing a feed gear-lock in an ink ribbon cartridge such as for a dot matrix printer.
When a pair of drive and idler gears feeds an ink ribbon into a storage space of a ribbon cartridge as shown in Fig.1(a), the ribbon is sometimes inadvertently pushed into a gap between one of the gears and the fixed wall. Then, the gear is locked and the ribbon is jammed, because the ribbon is twisted around the gear.
This invention prevents the gear-lock by covering the gap with a plastic sheet as shown in Fig.1(b). As shown in Fig.2, a flexible tip of the plastic sheet is extended into contact with the bottom of a gear tooth, for eliminating any gap between the plastic sheet and the gear. The plastic sheet is fixed to the wall by an adhesive at the area as shown in Section A-A and Fig.2, and is not fixed at the free end near the gear.
In operation, the flexible tip of the plastic sheet vibrates when the gears are rotated. And such a vibration pushes back the ribbon into the storage space.
The most desirable material of the plastic sheet is Polyester film, its thickness is around 0.125mm which provides enough durability for the life of a ribbon cartridge.