Single-reel tape cartridge

A single-reel tape cartridge which comprises:

• a generally rectangular flattened casing including upper and lower panels joined together to define a reel chamber therebetween, said lower panel having a drive access opening defined therein;
• a tape reel including a cylindrical hollow boss having a lower end closed and an upper end opening upwardly, and upper and lower flanges protruding radially outwardly from the upper and lower ends of the hollow boss, respectively, said tape reel having a length of tape wound around the hollow boss and positioned between the upper and lower flanges;
• a drive ring disposed at a lower portion of a hollow of the hollow boss and adapted to receive a rotary drive from a drive element of a tape drive mechanism when the drive element is brought into engagement with the drive ring in a planar contact fashion, said drive ring being supported in a fashion slidable up and down, but non-rotatable relative to the hollow boss;
• a reel retainer disposed between the upper panel of the casing and the drive ring;
• and
• a biasing spring disposed between the reel retainer and the upper panel of the casing for biasing the drive ring in one direction towards the lower panel of the casing, such that the drive ring can be sandwiched between the drive element and the reel retainer while the drive element is held in tight contact with an undersurface of the drive ring.