| 摘要 |
Pictures are fitted on the three sides of each bar so that with them in a common starting position each displays a separate picture. After rotation through 120 deg. they each display a second picture. Further rotation through the same angle provides a third picture on display. A final rotation brings the bars back to their starting position, with the first picture being shown. - Rotation is produced by a common electric motor running at high speed, e.g 3000 rev/min., the output shaft of which connects to a redn. gear, bringing the speed down to 300 rev/min. The shaft then engages in an interval gearbox (13,14,15) for the bars so that after a specific number of rotations e.g 30 rev., the bars are turned through 120 deg. |
