摘要 |
A motor (1) with belts (2) is coupled to two shafts (3,4) which are common for all the sheets. In each module of sheets are magnet couplings (5-7, 8-10). The sheets (11-13) can carry numerals (14) in series, or letters and different symbols. In each module is a code reader (16-18). The shafts (3,4) move in opposite directions and the sheets ae are rolled on to cylinders (19,20) In front of the sheets is a plastic or glass window (21), and the sheets are illuminated by a light tube (22). Preferably, the sheets are shite, and the numerals, etc. are black. A micro-computer is incorporated in the programming and control arrangement, and the system may be programmed so that a specific magnet coupling, e.g. (5) is connected. This causes a sheet (11) to be moved upwards, with a further magnet coupling (8) being disconnected. At the same time, a further magnet coupling e.g. (6) can be disconnected and another (9) connected, so that a second sheet (12) is moved downwards. |