Timepiece barrel with improved transmission of force

Patent metadata

Field	Value
Publication number	US-9513601-B2
Application number	US-201514799842-A
Country	US
Kind code	B2
Filing date	Jul 15, 2015
Priority date	Jul 22, 2014
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

A barrel includes a mainspring cooperating internally with a core, externally with a track of a drum by way of a resilient sliding bridle. The track and the bridle are of non-circular shape, nesting one inside the other in the free state of the bridle. The track and the bridle are arranged to make one raised portion of the bridle abuttingly engage with a sill of the track when the torque applied to the bridle is less than a torque limit value, and to allow radial constriction of the raised portion when the torque is greater than the limit value. The track and the bridle are arranged to allow the passage of the raised portion over the sill and to allow the bridle to travel angularly under the effect of the torque until the next encounter between the sill and the raised portion.

First claim

What is claimed is:

1. A timepiece barrel comprising:
at least one mainspring cooperating at an inner end thereof with a core pivoting about a pivot axis, and at an outer end thereof with an inner track of a barrel drum by way of a resilient sliding bridle,
wherein said inner track and said resilient sliding bridle are each of non-circular shape, and said resilient sliding bridle is nested inside said inner track in a free state of said resilient sliding bridle, and said inner track and said resilient sliding bridle are arranged such that a plurality of outwardly radially projecting raised portions comprised in said resilient sliding bridle are abuttingly engaged with a plurality of corresponding inwardly radially projecting sills comprised in said inner track when torque applied to said resilient sliding bridle is less than a torque limit value,
wherein said resilient sliding bridle forms a closed contour, and
wherein said raised portions of said resilient sliding bridle are subjected to a radial constriction when the torque applied to said resilient sliding bridle is greater than said torque limit value, to allow each of said raised portions to pass over each corresponding one of said sills and to allow said bridle to travel angularly under an effect of said torque until a next encounter between said sills and said raised portions.

2. The barrel according to claim 1 , wherein said inner track includes a plurality of peripheral housings each including a base located at the greatest distance from said pivot axis and said housings are each separated from the next housing by said sill located at the smallest distance from said pivot axis, and wherein said sliding bridle is integral with said mainspring and forms a one-piece assembly therewith, and includes a plurality of said raised portions, each of which, in the free state, has a maximum radius with respect to said pivot axis and each of which is separated from the next raised portion by a joining surface including an area of minimum radius with respect to said pivot axis, said maximum radius in the free state being greater than said smallest distance and less than said greatest distance.

3. The barrel according to claim 2 , wherein said radial constriction of said raised portions permits reduction of the radius thereof with respect to said pivot axis to a value lower than or equal to said smallest distance in order to pass over said sill.

4. The barrel according to claim 1 , wherein, in a maximum winding position of said mainspring, each passage of said raised portions over said sills returns an available torque in said drum from a higher slippage value to a lower moment of slippage value which is lower than said higher slippage value.

5. The barrel according to claim 1 , wherein said inner track includes a plurality of peripheral housings of cycloidal shape.

6. The barrel according to claim 1 , wherein said inner track and said resilient sliding bridle are of identical shape and of homothetic dimensions.

7. The barrel according to claim 1 , wherein said inner track and said resilient sliding bridle are of different shapes.

8. The barrel according to claim 1 , wherein said mainspring is fixed at several points of said resilient sliding bridle.

9. The barrel according to claim 1 , wherein said inner track includes a first number of said sills, wherein said resilient sliding bridle includes a second number of said raised portions, and wherein said second number is greater than or equal to said first number.

10. The barrel according to claim 1 , wherein said inner track includes a first number of said sills, wherein said resilient sliding bridle includes a second number of said raised portions, and wherein said second number is lower than or equal to said first number.

11. The barrel according to claim 1 , wherein during a winding operation, said mainspring is gradually wound around said core until a maximum degree of wind is reached and wherein cooperation between said raised portions of said resilient sliding bridle with said sills of said inner track of said barrel drum causes said resilient sliding bridle to deform under an action of the applied torque to perform disengagement as a result of which said resilient sliding bridle and said spring move forward one notch.

12. The barrel according to claim 11 , wherein relative shapes of said inner track of said barrel drum and of said raised portions of said resilient sliding bridle are arranged so that said disengagement corresponds to a predetermined maximum torque.

13. The barrel according to claim 11 , wherein said disengagement is obtained exclusively by a resilient deformation of one portion of said resilient sliding bridle greater than 50% of the periphery thereof.

14. A timepiece movement including the barrel according to claim 1 , wherein said core is arranged to cooperate with manual winding means.

15. A timepiece including at least one mechanism including said barrel according to claim 1 .

16. The barrel according to claim 1 , wherein an outer periphery of said closed contour is dimensionally similar to said inner track.

17. A timepiece barrel comprising:
at least one mainspring cooperating at an inner end thereof with a core pivoting about a pivot axis, and at an outer end thereof with an inner track of a barrel drum by way of a resilient sliding bridle,
wherein said inner track and said resilient sliding bridle are each of non-circular shape, and said resilient sliding bridle is nested inside said inner track in a free state of said resilient sliding bridle, and said inner track and said resilient sliding bridle are arranged such that at least one outwardly radially projecting raised portion comprised in said resilient sliding bridle is abuttingly engaged with at least one inwardly radially projecting sill comprised in said inner track when torque applied to said resilient sliding bridle is less than a torque limit value,
wherein said resilient sliding bridle includes a plurality of said raised portions and forms a closed contour an outer periphery of which is dimensionally similar to said inner track, and
wherein said at least one raised portion of said resilient sliding bridle is subjected to a radial constriction when the torque applied to said resilient sliding bridle is greater than said torque limit value, to allow said raised portion to pass over said sill and to allow said bridle to travel angularly under an effect of said torque until a next encounter between said sill and another of said raised portions.

Assignees

• Montres Breguet Sa
• Montres Breguet Sa

Inventors

• Karapatis Polychronis Nakis
• Sarchi Davide
• Piguet Rene
• Junod Benoit

Classifications

• G04B1/185

  Friction clutch between spring and spring cylinder (friction transmission between spring cylinder and gearing G04B1/165; other arrangements for protection against rupture or overwinding G04B1/20) · CPC title

• G04B1/18

  Constructions for connecting the ends of the mainsprings with the barrel or the arbor {(mainsprings and bridles therefor G04B1/14; clamping the hairspring on the regulator G04B18/026; clamping the hairspring on the arbor G04B17/32)} · CPC title

• G04B1/105 Primary

  having a form other than a helix (G04B1/12 and G04B1/14 take precedence) · CPC title

• G04B1/16 Primary

  Barrels; Arbors; Barrel axles (arrangements facilitating the removal of the mainspring G04B33/14) · CPC title