Timepiece movement comprising a device for equalising a motor torque

Patent metadata

Field	Value
Publication number	US-10474109-B2
Application number	US-201715686463-A
Country	US
Kind code	B2
Filing date	Aug 25, 2017
Priority date	Oct 19, 2016
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

Timepiece movement including a mechanism, a spring barrel for driving the mechanism, and an equalization device connected to the spring barrel. The spring barrel includes a drum and a motor spring to exert a driving torque which is variable as a function of the degree of winding-up of the motor spring. The equalization device is driven by the spring barrel and exerts an auxiliary torque which varies as a function of the degree of winding-up of the motor spring to counter variations in the motor torque. The equalization device includes a first and second magnetic elements being displaced from each other by exerting a magnetic force which varies as a function of the relative position of the first and second magnetic elements and produces the auxiliary torque.

First claim

What is claimed is:

1. A timepiece movement comprising:
a mechanism;
a spring barrel configured to drive the mechanism by means of a kinematic linkage being configured to exert a driving torque on the mechanism, the spring barrel including a motor spring configured to allow the spring barrel to exert a motor torque; and
an equalization device configured to equalize the driving torque, the equalization device being connected kinematically to the spring barrel and driven by the spring barrel, and exerting an auxiliary torque, the auxiliary torque being added to the motor torque and forming the driving torque, the auxiliary torque varying as a function of a degree of winding-up of the motor spring, countering a variation in the motor torque caused by the motor spring, and equalizing the driving torque within a useful range of the degree of winding-up,
wherein the equalization device includes a magnetic system including a first magnetic element and a second magnetic element,
wherein the first magnetic element is mounted concentrically on a shaft of the spring barrel or is fixed concentrically to a wheel that is connected kinematically to the spring barrel and the first magnetic element forms a magnetic cam having an outer edge with a spiral shape, and
wherein when the equalization device is driven by the spring barrel, the first and second magnetic elements being displaced from each other by exerting a magnetic force to each other, the magnetic force varying as a function of a relative position occupied by the first magnetic element and the second magnetic element and produces the auxiliary torque.

2. The timepiece movement according to claim 1 , wherein the auxiliary torque exerted by the equalization device is counter to the motor torque.

3. The timepiece movement according to claim 1 , wherein said magnetic cam includes a ferromagnetic material.

4. The timepiece movement according to claim 1 , wherein the magnetic cam and the second magnetic element form a radial magnetic system.

5. The timepiece movement according to claim 1 , wherein the magnetic cam and the second magnetic element form an axial magnetic system.

6. The timepiece movement according to claim 1 , wherein the second magnetic element is a bipolar permanent magnet.

7. The timepiece movement according to claim 1 , wherein the mechanism driven by the spring barrel is a ringing mechanism.

8. A timepiece movement comprising:
a mechanism;
a spring barrel configured to drive the mechanism by means of a kinematic linkage being configured to exert a driving torque on the mechanism, the spring barrel including a motor spring configured to allow the spring barrel to exert a motor torque; and
an equalization device connected kinematically to the spring barrel and driven by the spring barrel and exert an auxiliary torque being added to the motor torque and form together the driving torque, the auxiliary torque varying as a function of a degree of winding-up of the motor spring and counter a variation in the motor torque caused by the motor spring and equalize the driving torque within a useful range of a degree of winding-up,
wherein the equalization device includes
a magnetic system including a first magnetic element and a second magnetic element, the first and second magnetic elements being displaced from each other by exerting a magnetic force to each other when the equalization device is driven by the spring barrel, the magnetic force varying as a function of a relative position occupied by the first magnetic element and the second magnetic element and produces the auxiliary torque, and
an auxiliary reducing wheel work configured to operate in kinematic linkage with the spring barrel, the auxiliary reducing wheel work including a wheel, the wheel bearing the first magnetic element or the second magnetic element and being configured to effect less than one rotation while the spring barrel effects a plurality of rotations between a completely wound-up state of the motor spring and a completely unwound state of the motor spring.

9. The timepiece movement according to claim 8 , wherein the equalization device forms at least partially a device for indicating a power reserve.

10. A timepiece movement comprising:
a mechanism;
a spring barrel configured to drive the mechanism by a kinematic linkage being configured to exert a driving torque on the mechanism, the spring barrel including a motor spring configured to allow the spring barrel to exert a motor torque; and
an equalization device connected kinematically to the spring barrel and driven by the spring barrel and exert an auxiliary torque being added to the motor torque and form together the driving torque, the auxiliary torque varying as a function of a degree of winding-up of the motor spring and counter a variation in the motor torque caused by the motor spring and equalize the driving torque within a useful range of a degree of winding-up,
wherein the equalization device includes a magnetic system including a first magnetic element and a second magnetic element,
wherein when the equalization device is driven by the spring barrel, the first and second magnetic elements being displaced from each other by exerting a magnetic force to each other, the magnetic force varying as a function of a relative position occupied by the first magnetic element and the second magnetic element and produces the auxiliary torque, and
wherein the motor torque and the auxiliary torque exerted by the equalization device have a same direction.

Assignees

• Montres Breguet Sa

Inventors

• Legeret Benoit
• Sarchi Davide

Classifications

• G04B1/22 Primary

  Compensation of changes in the motive power of the mainspring (by mechanical shaping of the mainspring G04B1/14 {; automatic regulation of the pendulum G04B18/003; of the regulator G04B19/28}) · CPC title

• G04C5/00

  Electric or magnetic means for converting oscillatory to rotary motion in time-pieces, i.e. electric or magnetic escapements (regulators G04C3/00) · CPC title

• G04B1/20

  Protecting arrangements against rupture or overwinding of the mainspring located in the barrel or attached to the barrel (in connection with keys or the like G04B3/06, G04B3/10; in connection with automatic winding devices G04B5/24 {; protecting arrangements in which the spring and the spring cylinder are connected by friction G04B1/185; protecting arrangements G04B9/02; calibers with arrangements affording protection of the clockwork against damage as a consequence of a rupture of the mainspring G04B33/16; electric winding arrangements with protection against overwinding of mechanical clockworks G04C1/10; driving mechanisms for gramophones G11B19/22, G11B19/28}) · CPC title

• G04B1/16 Primary

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

• G04C5/005 Primary

  Magnetic or electromagnetic means · CPC title