| 摘要 |
A unit drive assembly (2) is used with postage meters (4) of the type which include a stationary base (6) and moveable print head (8). The base (6) and print head (8) are mechanically connected so that input information to the base (6) is mechanically transmitted to the print head (8). The assembly (2) includes one or more drive tracks (10) along which a series of balls (16) are positioned. A first portion (12) of the drive track (10) is carried by the base (6) while a second portion (14) is carried by the head (8). The first (12) and second (14) portions are aligned when the head (8) is in the home position; it is at this time a ball drive (28) carried by the base (6), moves the balls (16) along the track (10) discrete distances equal to one or more ball (16) diameters. The head (8) includes one or more print wheels (36) driven by the balls (16) positioned along the second portion (14) of the track (10) so that the distances the print wheels (36) rotate, which determines the value to be printed, depend upon the distances the balls (16) are driven along the tracks (10). |
