Arrangement for monitoring the operation of the ink ribbon of an ink-ribbon magazine

Claim 1

A devise for monitoring the physical condition of an ink ribbon (2) in an ink ribbon cassette (1) having an ink ribbon path and which is operatively but removably mounted on a printer unit (11), said device comprising: first and second electrical contact means (12, 6) mounted on the cassette adjacent the ink ribbon path so as to contact opposite faces of the ribbon and be normally separated from one another by the ribbon, one (12) of said first and second contact means being resiliently biased toward the other (6) to provide a tensioning influence on the ribbon, each of said first and second contact means having an edge (5a, 6a) extending beyond the corresponding edge of said ribbon; mounting means (15) on said printer unit adjacent said cassette when operatively mounted; third and fourth contact means (7, 8) disposed on said mounting means in spaced relation for contacting the extending edges of the first and second contact means respectively when the cassette is operatively mounted; means (19, 20) resiliently biasing said third and fourth contact means toward the extending edges of the first and second contact means; and indicator means (10) carried by the printer unit and electrically connected to the first and second contact means through the third and fourth contact means and the bias means to generate a signal whenever the physical condition of the ribbon allows the first and second contact means to touch one another.