Ribbon cartridge

Claim 1

A ribbon cartridge comprising: a casing formed with a ribbon outlet and a ribbon inlet; a supply reel; a supply of ribbon wound on the supply reel; a take-up reel; ribbon means provided adjacent to the take-up reel for feeding ribbon along a predetermined path from the supply reel onto the take-up reel; tension supply means for applying a tension to the ribbon; guide means located adjacent to the ribbon outlet and the ribbon inlet for guiding the ribbon which spans the ribbon outlet and the ribbon inlet outside the casing; ribbon end detector mounting means provided in the casing such that the ribbon advancing through the predetermined path between the supply reel and the ribbon outlet traverses the ribbon end detector mounting means; the tension supply means comprising a resilient clip member which has a generally U-shaped base portion, a pair of legs extending from opposite ends of the base portion beyond the maximum diameter of the ribbon on the supply reel and locally curved toward each other to fit in an annular recess formed in an upper portion of the supply reel, and parallel bends extending downwardly from the respective legs, one of the downward bends being fixed in place by a rigid portion of the casing while the other being held in a defined position in an elongate opening formed through the casing, said other downward bend urging the ribbon in such a direction that the ribbon is placed under tension, the U-shaped base portion being radially spaced from the upper portion of the supply reel in the opposite direction to the legs; the ribbon end detector mounting means comprising a detecting opening formed in the casing for receiving a detecting portion of a ribbon end detector; and second guide means provided adjacent to the opening for guiding the ribbon such that the ribbon is fed across the opening along the predetermined path; the second guide means comprising a first roller for receiving the ribbon from the supply reel, and a second roller for receiving the ribbon from the first roller to guide the ribbon to the ribbon outlet; the second guide means further comprising a first guide post opposite to the first roller and a second guide post opposite to the second roller, the ribbon being inserted into a gap between the first guide post and the first roller and a gap between the second guide post and the second roller; each of the first and second guide posts being formed with an obliquely truncated upper end which faces the corresponding roller.