Balance for timepieces and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-11809137-B2
Application number	US-201816767778-A
Country	US
Kind code	B2
Filing date	Dec 3, 2018
Priority date	Dec 22, 2017
Publication date	Nov 7, 2023
Grant date	Nov 7, 2023

Abstract

A balance for timepieces includes a rim, a hub, and at least one arm connecting the hub to the rim. At least one portion of the balance is made of an at least partially amorphous metal alloy. The at least partially amorphous metal alloy is based on an element chosen from the group consisting of platinum, zirconium and titanium, and has a coefficient of thermal expansion comprised between 7 ppm/° C. and 12 ppm/° C. The balance can be manufactured by moulding. A resonator can include such a balance and a monocrystalline quartz balance spring.

First claim

The invention claimed is:

1. A balance for a timepiece, comprising:
a rim;
a hub; and
at least one arm that extends continuously in a radial direction between the hub and said rim, a first end of the arm being directly connected to the hub and a second end of the arm being directly connected to the rim, the second end of the arm including a first branch and a second branch each directly connected to the rim, the first branch and the second branch being separate from one another to form a first housing between the first branch and the second branch, and a flexible inertia adjustment element is positioned in the first housing, the flexible inertial adjustment element extending from the first branch to the second branch,
wherein at least one portion of the balance is made of a partially or completely amorphous metal alloy,
wherein said at least partially amorphous metal alloy is based on an element chosen from the group consisting of platinum, zirconium and titanium, and has a coefficient of thermal expansion comprised between 7 ppm/° C. and 12 ppm/° C.

2. The balance according to claim 1 , wherein the hub and the arm are made of said at least partially amorphous metal alloy, the rim being made of a first material having a higher density than the density of said at least partially amorphous metal alloy of which the hub and the arms are made.

3. The balance according to claim 1 , wherein the rim, the hub, and the arm are made of said at least partially amorphous metal alloy.

4. The balance according to claim 3 , wherein the rim comprises overmoulded first inertia adjustment elements, said first inertia adjustment elements being made of a second material having a higher density than the density of said at least partially amorphous metal alloy.

5. The balance according to claim 1 , wherein the rim comprises housings configured to receive second inertia and/or unbalance adjustment elements.

6. The balance according to claim 1 , wherein the rim comprises housings configured to receive decorative and/or luminescent elements.

7. The balance according to claim 1 , wherein the hub comprises integrated, flexible, centring elements.

8. The balance according to claim 7 , wherein said integrated, flexible, centring elements are arranged on the inner edge of the hub.

9. The balance according to claim 1 , wherein either the arm, the rim, or the hub has a structured surface condition.

10. The balance according to claim 1 , wherein said at least partially amorphous metal alloy is platinum-based and has a coefficient of thermal expansion comprised between 8 ppm/° C. and 12 ppm/° C.

11. The balance according to claim 1 , wherein the flexible inertia adjustment element is V-shaped and bistable.

12. The balance according to claim 1 , wherein the flexible inertia adjustment element is made of a material having different expansion properties from the at least partially amorphous metal alloy.

13. The balance according to claim 1 , wherein the flexible inertia adjustment element is silicon or silicon oxide.

14. The balance according to claim 1 , wherein the second end of the arm includes a third branch, a second housing is formed between the second branch and the third branch, and another flexible inertia adjustment element is positioned in the second housing and extends between the second branch and the third branch.

15. A resonator comprising:
a balance comprising a rim, a hub, and at least one arm that extends continuously in a radial direction between the hub and said rim, a first end of the arm being directly connected to the hub and a second end of the arm being directly connected to the rim, the second end of the arm including a first branch and a second branch each directly connected to the rim, the first branch and the second branch being separate from one another to form a housing between the first branch and the second branch, and a flexible inertia adjustment element is positioned in the housing, the flexible inertial adjustment element extending from the first branch to the second branch, at least one portion of the balance being made of a partially or completely amorphous metal alloy,
wherein said at least partially amorphous metal alloy is based on an element chosen from the group consisting of platinum, zirconium and titanium, and has a coefficient of thermal expansion comprised between 7 ppm/° C. and 12 ppm/° C. and a monocrystalline quartz balance spring.

Assignees

• Swatch Group Res & Dev Ltd

Inventors

• Haemmerli Alexandre
• Gueissaz Francois
• Martin Jean-Claude
• Paratte Lionel
• Winkler Yves
• Di Domenico Gianni
• Winkler Pascal
• Helfer Jean-Luc
• Tombez Lionel
• Hinaux Baptiste
• Corson Donald William
• Willemin Michel

Classifications

• G04B17/227 Primary

  composition and manufacture of the material used (composition and manufacture of hairsprings G04B17/066; of springs G04B1/145; anti-magnetic alloys G04B43/007; ferrous alloys C22C; non-ferrous alloys C22C, B22F) · CPC title

• G04B17/222 Primary

  with balances (construction of balances G04B17/063) · CPC title