A timepiece indexing element cooperating coaxially with a component including an indexing relief element defining indexing positions, including a first bearing surface cooperating in abutment with the component, elastic return device exerting a radial thrust on this component to press it onto this first bearing surface, and indexing device cooperating with the indexing relief element, these elastic return devices include at least a first elastic arm including a first indexing surface comprised in this indexing device and arranged to exert a radial thrust force on the component and, at least a second elastic arm arranged to exert a radial thrust force on the first elastic arm.

A timepiece indexing element cooperating coaxially with a component including an indexing relief element defining indexing positions, including a first bearing surface cooperating in abutment with the component, elastic return device exerting a radial thrust on this component to press it onto this first bearing surface, and indexing device cooperating with the indexing relief element, these elastic return devices include at least a first elastic arm including a first indexing surface comprised in this indexing device and arranged to exert a radial thrust force on the component and, at least a second elastic arm arranged to exert a radial thrust force on the first elastic arm.

A device (1), and timepiece having the device, for displaying a succession of periodic events which form an annual cycle, including a periodic events indicator member (2) and a mechanism (4) for managing a duration during which the periodic events are displayed by the periodic events indicator member (2). The management mechanism includes a cam (8) for managing a duration during which the periodic events are displayed, which cam is arranged such that it controls the change from the indication of a periodic event to the indication of a subsequent periodic event by the periodic events indicator member, a periodic driver (10) for driving the management cam (8) and a member (6) disposed between the management cam and the periodic events indicator member and arranged such that it drives the periodic events indicator member (2) during a change in event. The device displays the periods of the zodiac.

A timepiece movement includes a control unit that determines a position of an indicating hand by detecting a rotation state of a rotor, and a train wheel that transmits a drive force of a stepping motor to the indicating hand, and that has a first gear, and a second gear and a third gear which mesh with the first gear. The first gear has a reference load unit that causes fluctuations in a load applied to the rotor in each case of meshing with the second gear and the third gear. A first line segment which connects a center of the first gear and a center of the second gear to each other forms an angle smaller than 180° with a second line segment which connects the center of the first gear and a center of the third gear.

Display mechanism (10) for a timepiece (1000), with a leap year display integrated in a month display, comprising a control mechanism (3) that drives, once per month, about an axis (D), a month display wheel set (2) arranged underneath a dial (1), having a month window (1C) in a quadrant allowing the display of only one quarter of the month display wheel set (2), which completes one revolution in four years, and bears, on an angular sector of 90°, at least one characteristic leap year marking, and either carries indices, each arranged to indicate one month on a static month scale of the dial (1), or equidistant month markings, wherein one of the month markings is pointed to by a fixed mark of the dial (1).

Display mechanism (10) for a timepiece (1000), with a leap year display integrated in a month display, comprising a control mechanism (3) that drives, once per month, about an axis (D), a month display wheel set (2) arranged underneath a dial (1), having a month window (1C) in a quadrant allowing the display of only one quarter of the month display wheel set (2), which completes one revolution in four years, and bears, on an angular sector of 90°, at least one characteristic leap year marking, and either carries indices, each arranged to indicate one month on a static month scale of the dial (1), or equidistant month markings, wherein one of the month markings is pointed to by a fixed mark of the dial (1).

A system (90) for driving and holding in position a mobile unit (50) for displaying time or time derivative information includes: a device (80) for driving a mobile unit (50) including a driving cam (13) and a driving lever (30) provided to drive a driving member (23), a device (40) for holding a mobile unit (50) in position, a device (70) for activating and deactivating the position-holding device (40) including a deactivation cam (22), and a device (12, 21) for mechanically coupling or synchronizing the driving cam (13) and the deactivation cam (22).

A system (90) for driving and holding in position a mobile unit (50) for displaying time or time derivative information includes: a device (80) for driving a mobile unit (50) including a driving cam (13) and a driving lever (30) provided to drive a driving member (23), a device (40) for holding a mobile unit (50) in position, a device (70) for activating and deactivating the position-holding device (40) including a deactivation cam (22), and a device (12, 21) for mechanically coupling or synchronizing the driving cam (13) and the deactivation cam (22).

A timepiece movement includes a movement case, a drive mechanism, a time mechanism driven by the drive mechanism, a day mechanism, and a day adjustment mechanism. The day mechanism is driven by the time mechanism through a frictional engagement therebetween. Once a torque generated by the day adjustment mechanism overcomes the frictional engagement, the day mechanism is permitted to be driven by the day adjustment mechanism. Therefore, an indicated day of the timepiece movement can be adjusted without pulling out of a day adjustment knob or an actuating shaft of the day adjustment mechanism.

A timepiece movement includes a movement case, a drive mechanism, a time mechanism driven by the drive mechanism, a day mechanism, and a day adjustment mechanism. The day mechanism is driven by the time mechanism through a frictional engagement therebetween. Once a torque generated by the day adjustment mechanism overcomes the frictional engagement, the day mechanism is permitted to be driven by the day adjustment mechanism. Therefore, an indicated day of the timepiece movement can be adjusted without pulling out of a day adjustment knob or an actuating shaft of the day adjustment mechanism.