Ribbon feed and take-up mechanism.

摘要

Apparatus for feeding ribbon in an impact printer or typewriter is provided in which the ribbon metering means are very simple and minimize the potential for damage to the ribbon. Ribbon is fed from a supply reel (12) to a take-up reel (16) each of which is adapted to support a portion of an inventory of ribbon running from the supply reel to the take-up reel. The apparatus includes a drive mechanism (20) which drives the take-up reel at a selected one of a plurality of different rotational velocities, apparatus for sensing the portion of the inventory of ribbon on one of the reels and for producing an electrical signal representative of the radius of said portion, and apparatus for selecting one of said rotational velocities in response to said signal. More particularly, the sensing means which sense the portion of the ribbon inventory remaining on the supply reel and the sensing means are preferably capacitive sensing means (21, 26).