Actuating mechanism for a flexible display hand

A mechanism for actuating a flexible display hand comprising a first drive pipe connected to a first end of a first flexible arm, and a second drive pipe connected to a first end of a second flexible arm, the first and second flexible arms being connected to one another by a tip at their second end, the first pipe being mounted at a defined first prestressing angle, and the second pipe being mounted at a defined second prestressing angle in the opposite direction to that of the first pipe, so that the elastically prestressed flexible display hand constantly maintains the entire actuating mechanism under tension during normal operation of the actuating mechanism, the actuating mechanism comprising a first cannon-pinion onto which the first drive pipe of the flexible display hand is driven, said first cannon-pinion being driven by a horological movement, said first cannon-pinion driving an intermediate wheel set which in turn drives a second cannon-pinion onto which the second drive pipe is driven, the flexible display hand moving between an initial position and a final position in which it makes a jump to return to its initial position, the flexible display hand changing shape and length during said movement, which induces additional elastic tension induced by the change in angular position of the second drive pipe relative to the first drive pipe which is added to the elastic tension induced by the mounting of the first and second drive pipes on the respective first and second cannon-pinions, a kinematic link between the intermediate wheel set and the second cannon-pinion being momentarily interrupted at a time when the flexible display hand makes its jump, the second cannon-pinion then being temporarily free to rotate about itself and disconnected from the rest of the actuating mechanism, so that the additional elastic tension is released, causing the second flexible arm to relax and the second cannon-pinion to pivot, the first and second cannon-pinions then being directly engaged via a pin in a slot, the first cannon-pinion driving not only the second cannon-pinion, but also the intermediate wheel set, until such time as the second cannon-pinion is again engaged with the intermediate wheel set.