Variable-geometry timepiece display mechanism with resilient hand

Patent metadata

Field	Value
Publication number	US-11860577-B2
Application number	US-201916965766-A
Country	US
Kind code	B2
Filing date	Jul 24, 2019
Priority date	Jul 31, 2018
Publication date	Jan 2, 2024
Grant date	Jan 2, 2024

Abstract

A variable timepiece display mechanism includes a resilient hand with two drive pipes integral with a one-piece flexible strip includes a tip or an index, with a driver for driving the pivoting of the pipe, and a stressor for stressing the strip so as to vary the position of the tip relative to the axis of the pipes, which includes an accelerator or decelerator device arranged such that it accelerates, or stabilizes the speed of, or slows down the first pipe and/or the second pipe over at least part of the angular travel thereof, which includes a device with a first differential gear on the drive gear train of the first pipe and/or a second differential gear on the drive gear train of the second pipe, and at least one cam forming an input of a differential gear.

First claim

The invention claimed is:

1. A variable-geometry timepiece display mechanism comprising:
at least one resilient hand which comprises a first drive pipe integral with a first end of a flexible strip, and a second drive pipe integral with another end of said flexible strip, and which comprises a display index or tip which, in an unstressed free state of said resilient hand wherein both said first pipe and said second pipe are not subjected to any stress and are remote from one another, is remote from said first pipe and from said second pipe, the operating position of said resilient hand being a stressed position where said first pipe and said second pipe are coaxial to one another about an output axis; and
first means for driving said first pipe about said output axis, and second means for driving said second pipe about said output axis, said first drive means and second drive means being arranged so as to deform said flexible strip by varying the angular position of said second pipe relative to the angular position of said first pipe about said output axis, and so as to vary the radial position of said display index or tip relative to said output axis, whereby said first drive means and/or second stressing means comprise an accelerator or decelerator device, which is arranged such that it accelerates, or stabilizes the speed of, or slows down at least said first pipe and/or said second pipe over at least part of the angular travel thereof,
wherein said accelerator or decelerator device comprises a first shaped gear train including a first shaped wheel driven by a first cannon-pinion, the first shaped wheel gears with a second shaped wheel that idles about a first axis, the second shaped wheel being pivotably integral with a third shaped wheel, the third shaped wheel gears with a fourth shaped wheel that pivots about the output axis and comprises a second cannon-pinion attached to the first pipe,
wherein said accelerator or decelerator device comprises a second shaped gear train including a fifth shaped wheel driven by the first cannon-pinion, the fifth shaped wheel gears with a sixth shaped wheel that idles about a second axis, the sixth shaped wheel being pivotably integral with a seventh shaped wheel, the seventh shaped wheel gears with an eighth shaped wheel that pivots about the output axis and comprises a third cannon-pinion attached to the second pipe, and
wherein each of the first through eighth shaped wheels is non axisymmetric.

2. The mechanism according to claim 1 , wherein said resilient hand comprises a plurality of flexible segments that are joined end-to-end at at least one tip forming a display index, a first flexible segment thereof extends between said first pipe and a first tip, and said second pipe, said display mechanism comprising an input wheel set arranged so as to be driven such that it pivots about an input axis by a movement, and which defines an input angle with a reference, and comprising said first means for driving said first pipe about said output axis, and second means for stressing at least said first flexible segment, which are arranged so as to vary the position of at least said first tip relative to said output axis, said first tip being at a variable distance from said first pipe, as a function of forces applied to said flexible strip by said second stressing means, wherein said second stressing means comprise said second means for driving said second pipe in an assembled and stressed state of said resilient hand in which both said first pipe is driven by said first drive means, and said second pipe is driven by said second drive means.

3. The mechanism according to claim 2 , wherein said first pipe is advanced or delayed relative to the value of said input angle, which is symmetric to the delay or advance of said second pipe relative to said input angle, such that said first tip always displays, relative to said output axis and said reference, an angle that is equal to said input angle.

4. The mechanism according to claim 1 , wherein said first pipe is advanced or delayed relative to the value of said input angle, which is, as an absolute value, different to the delay or advance of said second pipe relative to said input angle, such that said first tip displays, relative to said output axis and said reference, an angle that is variable relative to said input angle throughout the length of the travel thereof.

5. The mechanism according to claim 1 , wherein said hand is arranged such that it travels a total non-retrograde path and that, over said total path, an average speed of said first pipe is equal to an average speed of said second pipe.

6. The mechanism according to claim 1 , wherein said first drive means and said second stressing means are arranged so as to drive said resilient hand over the entirety of the angular travel thereof about said output axis, and provide it, in projection on a display plane or on a dial, and at different angular positions of said resilient hand, with at least one first shape in which said flexible segments comprised in said flexible strip do not cross paths outside of said first pipe, and at least one second shape in which said flexible segments comprised in said flexible strip cross paths outside of said first pipe.

7. The mechanism according to claim 6 , wherein said first shape is an almond shape, and said second shape is a heart shape.

8. The mechanism according to claim 1 , wherein said first flexible segment bears said first pipe at a first end, and a second flexible segment joined to said first flexible segment bears said second pipe at a second end, and wherein, in said free state of said resilient hand, said first end and said second end are remote from one another, or form a non-zero angle with one another from said tip at which said first flexible segment and said second flexible segment are joined.

9. The mechanism according to claim 8 , wherein said first shaped gear train and said second shaped gear train are arranged such that they symmetrically control said first pipe and said second pipe, such that said first flexible segment and said second flexible segment are symmetrical relative to a radial originating from said output axis and passing by way of said tip at which said first flexible segment and said second flexible segment are joined, over at least part of the angular travel of said resilient hand.

10. The mechanism according to claim 1 , wherein the output of said second drive means of said second pipe is coaxial to the output of said first drive means of said first pipe.

11. The mechanism according to claim 1 , wherein said first shaped gear train and said second shaped gear train are arranged so as to accelerate or respectively brake said first pipe, and to brake or respectively accelerate said second pipe over only part of the angular travel of said resilient hand.

12. The mechanism according to claim 1 , wherein in the free state, said resilient hand extends over a first planar level comprising said first pipe and over a second planar level comprising said second pipe, and comprises a connecting area between said first planar level and said second planar level at one said tip between a first flexible segment bearing said first pipe and a second flexible segment joined to said first flexible segment and bearing said second pipe, and wherein said resilient hand is arranged such that it is mounted in a non-twisted manner in a stressed operating position wherein said first pipe and said second pipe are superimposed on one another.

13. The mechanism according to claim 1 , wherein in the free state, said resilient hand extends over as many parallel levels as there are said flexible segm

Assignees

• Montres Breguet Sa

Inventors

• Stranczl Marc
• Pittet Jan

Classifications

• G04B19/02 Primary

  Back-gearing arrangements between gear train and hands {(transmissions in general G04B13/00)} · CPC title

• G04B9/005

  by optical indication of the amount of winding · CPC title

• G04B13/001 Primary

  with the choice of adjustable or varying transmission ratio · CPC title

• G04B13/007

  with differential work · CPC title

• G04B13/008

  Differentials · CPC title