Optimised escapement with security means

• US 9,665,067 B2
• Filed: 12/09/2014
• Issued: 05/30/2017
• Est. Priority Date: 12/23/2013
• Status: Active Grant

• Current Assignee: Nivarox-Far S.A. (The Swatch Group AG)
• Original Assignee: Nivarox-Far S.A. (The Swatch Group AG)
• Inventors: Stranczl, Marc, Di Domenico, Gianni, Winkler, Pascal
• Primary Examiner(s): Miska, Vit W
• Application Number:
  US15/106,946
• Publication Number:
  US 20160357149A1
• Time in Patent Office: 903 Days
• CPC Class Codes: G04B 15/08 Lever escapements
• CPC Class Codes: G04B 15/12 Adjusting tools therefor G04D1/02; Restricting the amplitude of the lever or the like adjusting the gear train G04B35/00
• CPC Class Codes: G04B 15/14 Component parts or constructional details, e.g. construction of the lever or the escape wheel assembly and manufacture of the spring G04B1/145; assembly and manufacture of components, e.g. pinions, spindles G04B13/02; lubrication of clockwork bearings G04B31/008; oils for clockwork bearings in general G04B31/08
• CPC Class Codes: G04B 17/32 Component parts or constructional details, e.g. collet, stud , virole or piton
• CPC Class Codes: G04C 5/005 Magnetic or electromagnetic means

Abstract

An escapement mechanism including a stop member including a first actuator cooperating with a resonator and a second actuator cooperating with an escape wheel set subjected to a drive torque lower than a nominal torque. The first actuator includes a magnetically or electrically charged pole piece, the resonator includes a magnetically or electrically charged track, and the pole piece and/or the track create, in an air gap between the pole piece and the track, a magnetic or electrostatic field having an intensity ensuring relative driving of the stop member and of the resonator when the torque is lower than the nominal torque. The stop member and/or the resonator include an arresting mechanism limiting relative movement between the actuator and the resonator when the torque is greater than the nominal torque.

Claims

1. A timepiece escapement mechanism comprising:

a stop member between a resonator and an escape wheel set subjected to a drive torque lower than or equal to a substantially non-zero nominal torque, the stop member comprising at least a first actuator arranged to cooperate with the resonator and at least a second actuator arranged to cooperate with the escape wheel set, the at least one first actuator comprising at least a first magnetically charged or ferromagnetic, or respectively electrically charged or electrostatically conductive pole piece; and

the resonator comprising at least one first magnetically charged or ferromagnetic, or respectively electrically charged or electrostatically conductive track, and at least the first pole piece and/or the first track creating a first magnetic or electrostatic field in a first air gap between the at least one first pole piece and the first track;

wherein the first field has an intensity ensuring relative driving of the stop member and of the resonator provided that the torque applied to the escape wheel set is lower than or equal to the nominal torque,

wherein the stop member and/or the resonator comprises first arresting means for limiting relative movement between the first actuator and the resonator when the torque applied to the escape wheel set is greater than the nominal torque, and

wherein the first arresting means comprises a magnetic or electrically charged barrier arranged to create a magnetic or electrostatic field higher than the first magnetic or electrostatic field beyond the first air gap.

2. The timepiece escapement according to claim 1, wherein the arresting means comprises at least one mechanical stop member.

3. The escapement mechanism according to claim 1,

wherein the at least one second actuator comprises at least a second magnetically charged or ferromagnetic, or respectively electrically charged or electrostatically conductive pole piece, and

wherein the escape wheel set comprises at least one second magnetically charged or ferromagnetic, or respectively electrically charged or electrostatically conductive track, and

at least the second pole piece and/or the second track create a second magnetic or electrostatic field in a second air gap between the at least one second pole piece and the second track, the second field having an intensity ensuring relative driving of the stop member and of the escape wheel set provided torque applied to the escape wheel set is lower than or equal to the nominal torque, and

wherein the stop member and/or the escape wheel set comprises second arresting means for limiting relative movement between the at least one second actuator and the escape wheel set when the torque applied to the escape wheel set is greater than the nominal torque.

4. The escapement mechanism according to claim 3, wherein the resonator, the stop member, the escape wheel set, the first pole piece and the first track, the second pole piece and the second track, together form a first contactless escapement mechanism arranged to operate when the torque applied to the escape wheel set is lower than or equal to the nominal torque, and without allowing mechanical banking cooperation between the first arresting means and/or the second arresting means and the opposing surfaces of the resonator, or of the stop member, or of the escape wheel set.

5. The escapement mechanism according to claim 3, wherein the resonator, the stop member, the escape wheel set, the first arresting means, and the second arresting means, together form a second mechanical escapement mechanism arranged to operate when the torque is greater than the nominal torque.

6. The escapement mechanism according to claim 4, wherein the resonator, the stop member, the escape wheel set, the first arresting means, and the second arresting means, together form a second mechanical escapement mechanism arranged to operate when the torque is greater than the nominal torque.

7. The escapement mechanism according to claim 1, wherein the stop member comprises first arresting means, formed by a set of horns, and wherein the resonator comprises first arresting means, formed by a roller pin arranged to cooperate with the set of horns.

8. The escapement mechanism according to claim 7, wherein the set of horns is supplemented by a guard pin, and the roller pin is supplemented by a roller notch arranged to cooperate with the guard pin.

9. The escapement mechanism according to claim 3, wherein the stop member comprises second arresting means, formed by a set of pallet-stones, and wherein the escape wheel set comprises second arresting means, formed by a toothing arranged to cooperate with the set of pallet-stones.

10. The escapement mechanism according to claim 1, wherein the first track includes a magnetized layer of variable thickness, or respectively, an electrically charged layer of variable thickness, or a magnetized layer of constant thickness but variable magnetization, or respectively, an electrically charged layer of constant thickness but variable electrical charge, or micro-magnets with variable surface density, or respectively, electrets with variable surface density, or a ferromagnetic layer of variable thickness, or respectively, an electrostatically conductive layer of variable thickness, or a ferromagnetic layer of variable shape, or respectively, an electrostatically conductive layer of variable shape, or a ferromagnetic layer wherein the surface density of holes is variable, or respectively, an electrostatically conductive layer wherein the surface density of holes is variable.

11. The escapement mechanism according to claim 3, wherein the second track includes a magnetized layer of variable thickness, or respectively, an electrically charged layer of variable thickness, or a magnetized layer of constant thickness but variable magnetization, or respectively, an electrically charged layer of constant thickness but variable electrical charge, or micro-magnets with variable surface density, or respectively, electrets with variable surface density, or a ferromagnetic layer of variable thickness, or respectively, an electrostatically conductive layer of variable thickness, or a ferromagnetic layer of variable shape, or respectively, an electrostatically conductive layer of variable shape, or a ferromagnetic layer wherein the surface density of holes is variable, or respectively, an electrostatically conductive layer wherein the surface density of holes is variable.

12. The escapement mechanism according to claim 1, wherein the stop member is a pallet-lever.

13. A timepiece movement comprising at least one escapement mechanism according to claim 1.

14. A timepiece comprising at least one timepiece movement according to claim 13.