Watch pivot device

Patent metadata

Field	Value
Publication number	US-11392091-B2
Application number	US-201816047646-A
Country	US
Kind code	B2
Filing date	Jul 27, 2018
Priority date	Jul 31, 2017
Publication date	Jul 19, 2022
Grant date	Jul 19, 2022

Abstract

Method of assembly of a watch pivot device (100) or a watch mechanism (200) or a watch movement (300) or a timepiece (400), the watch pivot device (100) or the watch mechanism (200) or the watch movement (300) or the timepiece (400) comprising a pivot (1) and a bearing (2), the method comprising the following stages: (i) supplying the pivot (1); (ii) supplying the bearing (2); (iii) applying, to at least one surface (101, 102, 211, 221) of the pivot and/or of the bearing, a lubricant of which the kinematic viscosity at a temperature of 20° C. is greater than 1.5 St; and (iv) positioning the pivot in the bearing.

First claim

The invention claimed is:

1. A method of assembly of a watch pivot device or a watch mechanism or a watch movement or a timepiece, the watch pivot device or the watch mechanism or the watch movement or the timepiece comprising a pivot and a bearing, in a manner to reduce the coefficients of friction between the pivot and the bearing in horizontal positions and vertical positions of the pivot during use by applying a lubricant having a particular kinematic viscosity in relation to a moment of inertia of the pivot, the method comprising:
supplying the pivot;
supplying the bearing;
applying, to at least one surface of the pivot and/or of the bearing, a lubricant of which the kinematic viscosity at a temperature of 20° C. is greater than 1.5 St and lower than 50 St; and
positioning the pivot in the bearing,
wherein the lubricant applies a higher resistive torque between the pivot and the bearing in the horizontal position of the pivot in comparison to the vertical position of the pivot such that frictional torque between the pivot and the bearing is harmonized regardless of a position of the pivot between the horizontal position to the vertical position of the pivot.

2. The method as claimed in claim 1 , wherein the lubricant is a polyalphaolefin-based lubricant.

3. The method as claimed in claim 1 , wherein the kinematic viscosity of the lubricant at a temperature of 20° C. is greater than 1.6 St.

4. The method as claimed in claim 1 , wherein the pivot is a balance staff pivot of an oscillator.

5. The method as claimed in claim 4 , wherein the oscillator includes a balance wheel or a hairspring.

6. The method as claimed in claim 1 , wherein the pivot is a pivot of an element having a mass greater than 5×10 −2 g.

7. A watch pivot device or a watch mechanism or a watch movement or a timepiece, obtained by the implementation of a method as claimed in claim 1 .

8. The device as claimed in claim 7 , wherein the lubricant is a polyalphaolefin-based lubricant.

9. The device as claimed in claim 7 , wherein the kinematic viscosity of the lubricant at a temperature of 20° C. is greater than 1.6 St.

10. The device as claimed in claim 7 , wherein the pivot is a balance staff pivot of an oscillator.

11. The device as claimed in claim 10 , wherein the oscillator includes a balance wheel or a hairspring.

12. The device as claimed in claim 7 , wherein the pivot is a pivot of an element having a mass greater than 5×10 −2 g.

13. A watch mechanism comprising a device as claimed in claim 7 .

14. A watch movement comprising a mechanism as claimed in claim 13 .

15. A timepiece comprising a movement as claimed in claim 14 .

16. The device as claimed in claim 7 , wherein the bearing comprises at least one jewel.

17. The method as claimed in claim 1 , wherein the bearing comprises at least one jewel.

18. The method as claimed in claim 1 , wherein the pivot is a pivot of an element having a moment of inertia greater than 5×10 −10 kg·m 2 .

19. A watch pivot device comprising a pivot and a bearing, at least one surface of the pivot and/or of the bearing being coated with a lubricant of which the kinematic viscosity at a temperature of 20° C. is greater than 1.5 St,
wherein the lubricant applies a higher resistive torque between the pivot and the bearing in the horizontal position of the pivot in comparison to the vertical position of the pivot such that frictional torque between the pivot and the bearing is harmonized regardless of a position of the pivot between the horizontal position to the vertical position of the pivot.

Assignees

• Rolex Sa

Inventors

• Burger Frédéric
• Chauveau Vanessa
• Mbaye Aziz

Classifications

• G04B31/0082 Primary

  with jewel hole and cap jewel (shock damping bearings with jewel hole and cap jewel G04B31/04) · CPC title

• G04B31/008

  Jewel bearings (G04B31/04 takes precedence) · CPC title

• G04B31/08 Primary

  Lubrication {(self-lubricated plastic bearings G04B31/016; lubrication of the escape wheel G04B15/14; lubrication of synchronous clockworks G04C15/009; lubrication devices and lubricant containers G04D5/00)} · CPC title

• G04B13/02

  Wheels; Pinions; Spindles; Pivots (bearings G04B31/00 {; chain wheels, spindles for chain wheels, also chains and driving weights G04B1/08}) · CPC title

• G04B31/06

  Manufacture or mounting processes · CPC title