Actuation mechanism of flexible display hand driven by a clockwork movement
An actuation mechanism ( 60 ) of a flexible hand ( 44 ) to which a clockwork movement applies a first angular rotation (θ 1 ), the flexible hand ( 44 ) including a first drive barrel ( 46 ) and a second drive barrel ( 50 ) connected to a tip ( 54 ) of the flexible hand ( 44 ) by a first and a second flexible arm ( 48 ), the first drive barrel ( 46 ) being provided with a first toothing ( 56 ) and the second drive barrel ( 50 ) being provided with a second toothing ( 58 ), the first and second drive barrels ( 46, 50 ) being mounted so the first toothing ( 56 ) of the first drive barrel ( 46 ) engages with the second toothing ( 58 ) of the second drive barrel ( 50 ) in the stressed position of the flexible hand ( 44 ), the angular rotation (θ 1 ) applied by the clockwork movement to the actuation mechanism ( 60 ) being modulated by an angle of rotation (φ) by the actuation mechanism ( 60 ).
1 . An actuation mechanism of a flexible hand to which a clockwork movement applies a first angular rotation θ 1 , the flexible hand comprising:
a first flexible arm and a second flexible arm joined together at a tip; and
a first drive barrel integrally formed with the first flexible arm at an end of the first flexible arm, and a second drive barrel integrally formed with the second flexible arm at an end of the second flexible arm, the first drive barrel being integrally formed with a first toothing extending radially outward from an outer side of the first drive barrel, and the second drive barrel being integrally formed with a second toothing extending radially outward from an outer side of the second drive barrel,
the first and second drive barrels being spaced apart from one another when the flexible hand is in a free, unstressed state, an operating position in which the flexible hand has a defined shape and length being a stressed position in which the first drive barrel is mounted at a defined first prestressed angle, and the second drive barrel is mounted at a defined second prestressed angle in opposite direction to the first drive barrel, the first drive barrel and the second drive barrel being arranged such that the first toothing of the first drive barrel is engaged with the second toothing of the second drive barrel in the stressed position of the flexible hand,
the flexible hand being arranged so as to change the shape and length when the angular position of the second drive barrel is varied by pivoting relative to the first drive barrel, the angular rotation applied by the clockwork movement to the actuation mechanism being modulated by an angle of rotation φ by the actuation mechanism, this angle of rotation φ, applied in opposite direction to the first and second flexible arms of the flexible hand by meshing the first toothing of the first drive barrel with the second toothing of the second drive barrel, determining the change in shape and length of the flexible hand.
2 . The actuation mechanism according to claim 1 , further comprising a planetary wheel-holding frame to which the clockwork movement applies the first angular rotation θ 1 , the planetary wheel-holding frame being provided with a first and a second tube on which a first and a second driving barrel-pinion respectively are mounted to be freely rotatable, the actuation mechanism also comprising a cam follower finger arranged to run along the profile of a cam against which the cam follower finger is held by the resilience of the flexible hand, the cam being a fixed element of the actuation mechanism, the cam follower finger being arranged to follow the profile of the cam so that the first angular rotation θ 1 applied by the clockwork movement to the planetary wheel-holding frame is further modulated by the angle of rotation φ applied in the direction opposite the second flexible arm by the first flexible arm by engagement of the first toothing with the second toothing, the angle modulation φ determining the change in shape and length of the flexible hand.
3 . The actuation mechanism according to claim 2 , wherein one of the driving barrel-pinions is equipped with the cam follower finger.
4 . The actuation mechanism according to claim 2 , wherein one of the first or second flexible arms is equipped with the cam follower finger.
5 . A flexible hand comprising:
a first flexible arm and a second flexible arm joined together at a tip; and
a first drive barrel integrally formed with the first flexible arm at an end of the first flexible arm, and a second drive barrel integrally formed with the second flexible arm at an end of the second flexible arm, the first drive barrel being integrally formed with a first toothing extending radially outward from an outer side of the first drive barrel, and the second drive barrel being integrally formed with a second toothing extending radially outward from an outer side of the second drive barrel,
the first and second drive barrels being spaced apart from one another when the flexible hand is in an unstressed free state, an operating position in which the flexible hand has a defined shape and length being a stressed position in which the first drive barrel is mounted at a first defined prestressed angle, and the second drive barrel is mounted at a second defined prestressed angle in opposite direction to the first drive barrel, the first drive barrel and the second drive barrel being arranged such that the first toothing of the first drive barrel is in engagement with the second toothing of the second drive barrel in the stressed position of the flexible hand,
the flexible hand being arranged so as to change shape and length when the angular position of the second drive barrel varies pivotally relative to the first drive barrel.