Abstract:
There is described a numbering unit (6) of a numbering device (1), the numbering unit (6) comprising rotatable numbering wheels (7) carrying alpha-numerical symbols thereon, which numbering wheels (7) are disposed next to each other and rotate about a common rotation axis (17). The numbering unit (6) comprises a releasable indexing mechanism (50'; 7a', 510, 520) for mechanically aligning and maintaining the position of the numbering wheels (7) during a numbering operation, once the numbering wheels (7) have been rotated to their target positions. The releasable indexing mechanism (50'; 7a', 510, 520) comprises a movable indexing member (50'; 510) extending parallel to the rotation axis, which movable indexing member (50'; 510) is adapted to be pushed into indexing grooves (7a') provided on an inner periphery of the numbering wheels (7).