Movement for timepiece with retrograde display
A movement for a timepiece having a retrograde display member displaying at least one time division, includes a going train, elements for driving the display member including a wheel unit driven by the going train and carrying a first cam sharing the same axis of rotation. The movement also includes a rocker supporting a probe held against the edge of the first cam by deformable elastic elements undergoing a deformation of variable amplitude. This results in the application of a corresponding force on the rocker in proportion to the distance between the probe and the axis of rotation of the first cam. The movement also includes drive members to connect the rocker to a retrograde display member. A force-regulating device is interposed between the elastic elements and the rocker.
1. A display module for timepiece movement designed to drive a retrograde display member displaying at least one time division, comprising a frame supporting
means for driving said retrograde display member comprising a wheel unit designed to be driven from a going train of the clockwork movement and supporting a first cam, sharing an axis of rotation with said wheel unit in reference to said frame,
a lever supporting a feeler-spindle arranged so as to bear against the periphery of said first cam under the effect of deformable elastic means undergoing a deformation of variable amplitude, causing the application of a corresponding force on said lever, depending on the distance separating said feeler-spindle from said axis of rotation of the first cam, transmission means designed to connect said lever to said drive means,
wherein a regulating device of said force is inserted between said elastic means and said lever.
2. The display module of claim 1 , wherein said wheel unit is driven by a wheel integral with a cylinder wheel tube, said lever comprising a rack having a toothing arranged engaged with a toothing of a pinion mounted free in rotation on said cylinder wheel tube and integral in rotation with an additional tube designed to ensure the driving of a display member for hour information.
3. The display module of claim 2 , wherein said feeler-spindle, said axis of rotation of said first cam and the region in which said rack and said pinion are engaged are substantially aligned.
4. The display module of claim 1 , wherein said support of said feeler-spindle on said first cam generates a frictional force decreasing when said distance between said feeler-spindle and said axis of rotation of said first cam increases.
5. The display module of claim 1 , wherein said regulating device comprises a second cam connected to said lever and having a periphery on which said force is applied.
6. The display module of claim 5 , wherein said second cam and said lever share a same axis of rotation (X) in reference to said frame and are integral in rotation.
7. The display module of claim 6 , wherein said second cam has a heart-shaped periphery.
8. The display module of claim 5 , wherein at least one portion of said periphery designed to come into contact with said feeler-spindle corresponds to a logarithmic curve portion.
9. The display module of claim 5 , wherein said elastic means comprise a long spring having a straight portion whereof one free end is arranged bearing against the periphery of said second cam.
10. The display module of claim 2 , wherein said additional tube, designed to support said display member, is integral with an additional cam, sharing the same axis of rotation, and having a periphery of variable radius designed to cooperate with an additional feeler-spindle supported by an additional lever having a support surface arranged to cooperate with said elastic means.
11. The display module of claim 10 , wherein the periphery of said additional cam has a shape at least partially corresponding to a logarithmic curve portion.
12. The display module of claim 10 , wherein said additional feeler-spindle supports a runner arranged to provide the contact between said additional lever and the periphery of said additional cam.
13. The display module of claim 2 , wherein said support of said feeler-spindle on said first cam generates a frictional force decreasing when said distance between said feeler-spindle and said axis of rotation of said first cam increases.
14. The display module of claim 2 , wherein said regulating device comprises a second cam connected to said lever and having a periphery on which said force is applied.
15. The display module of claim 3 , wherein said support of said feeler-spindle on said first cam generates a frictional force decreasing when said distance between said feeler-spindle and said axis of rotation of said first cam increases.
16. The display module of claim 3 , wherein said regulating device comprises a second cam connected to said lever and having a periphery on which said force is applied.
17. The display module of claim 3 , wherein said additional tube, designed to support said display member, is integral with an additional cam, sharing the same axis of rotation, and having a periphery of variable radius designed to cooperate with an additional feeler-spindle supported by an additional lever having a support surface arranged to cooperate with said elastic means.
18. A timepiece movement designed to drive a retrograde display member displaying at least one time division, comprising a frame supporting
a going train,
means for driving said retrograde display member comprising a wheel unit arranged so as to be driven from said going train and supporting a first cam, sharing the same axis of rotation as said wheel unit in reference to said frame,
a lever supporting a feeler-spindle arranged so as to bear against the periphery of said first cam under the effect of deformable elastic means undergoing a deformation of variable amplitude, driving the application of a corresponding force on said lever, depending on the distance separating said feeler-spindle from said axis of rotation of said first cam, transmission means designed to connect said lever to said drive means,
wherein a regulating device of said force is inserted between said elastic means and said lever.
19. A timepiece comprising a case closed by a glass wherein is housed the movement of claim 18 , arranged so as to drive a display member having at least one time size visible through said glass, wherein said time size is displayed on an angular sector having an angle greater than 60 degrees.