| 摘要 |
As a carrier including a wheel portion 4 is rotated about a vertical axis, restraining members 8 restrain flip- boards 2 against movement about that axis while pivot shafts 3 of the latter are between angular positions A and B on the one hand and positions C and D on the other hand. When any one of the flip-boards is thus restrained, rotation of the carrier causes torsion coil springs 1 provided on said pivot shafts to become progressively tensioned. Upon movement from position B to position C, or from position D to position A, the energy thus stored in the springs causes the flip-board to flip-over, thereby relaxing the springs except for a residual amount of spring tension. Therefore, each spring is twice tensioned and twice relaxed during one complete revolution of the carrier. The device may indicate mineral oil prices or the time. Two such devices may be arranged back-to-back with the flip- boards moving across alternately. <IMAGE> |
