HK1231972A1 - Power reserve indicator for timepieces - Google Patents

Description

Energy storage indicator for a timepiece

Technical Field

The invention relates to a power source for a timepiece, comprising a barrel pivoting about an arbour housing a mainspring mounted between a barrel wheel of said barrel and said arbour, the arbour carrying a ratchet wheel driving said arbour and rotating integrally with said ratchet wheel, said power source comprising a differential gear (differential gear) of which a first input is indirectly driven by said ratchet wheel and a second input is said barrel wheel of which an output is a pivoted output wheel coaxial with said arbour and arranged to form or drive an energy storage indicator, and said differential gear comprising a ball driving a housing forming said output wheel of a cage, said ball cooperating with an upper surface of said barrel and a lower surface of a differential disc (differential disc) arranged on the side of said upper surface of said barrel wheel, said differential disc being arranged to pivot on said arbour, coaxial with the spindle and connected to the ratchet or to the bottom plate by a friction mechanism and forming the first input means.

The invention also relates to a stored energy indicator mechanism for a stored energy display of a timepiece power source including a barrel formed by a barrel wheel provided with a toothing and a cover, which together enclose a mainspring, the mainspring being mounted between said barrel and a barrel arbour about which the barrel pivots, said barrel arbour carrying and rotating integrally with a transmission ratchet external to said barrel and opposite to said cover or said barrel wheel.

The invention also relates to a differential subassembly arranged to be mounted on a timepiece arbour.

The invention also relates to a timepiece movement including at least one such power source and/or at least one such energy storage indicator mechanism.

The invention also relates to a watch or timepiece comprising at least one such power source and/or at least one such stored energy indicator mechanism.

The invention concerns the field of mechanical timepieces, in particular watches, comprising at least one power source comprising a main barrel.

The present invention relates to a complex mechanism consisting of an available energy storage display.

Background

The energy storage indicator of a mechanical watch powered by one or more barrels is a complex mechanism useful for the user.

However, the energy storage indicator is scarce because it often requires a large number of modifications to the basic movement, while it occupies a large space in terms of volume and thickness. Such complex mechanisms therefore generally remain for the movement housed in a quite spacious case, making it difficult to expand its use.

European patent EP 1970778 in the name of montes BREGUET SA describes an energy storage indicator comprising a planetary differential of very complex design, whose first input means is connected to the barrel arbour, whose second input means is connected to the barrel, and whose output means is connected to the energy storage indicator. The differential carrier is coaxial with the barrel arbour and the second input device is integral with the barrel cover. The output is a transmission wheel with an annulus gear, which is kinematically connected to the first input by means of intermeshing planet gears, the transmission wheel being carried by the cover.

German patent DE 1015747 in the name of FELSA AG describes a similar differential gear having a first input connected to the barrel arbour through a gear train, a second input connected to the barrel, and a differential output at an output wheel comprising a housing for a ball or roller bearing interposed between the barrel and the last wheel of the gear train.

Disclosure of Invention

The present invention proposes to provide an energy storage display device which is easy to produce, cheap and occupies a minimum amount of space by converting an existing mechanical movement.

To this end, the invention relates to a timepiece power source according to claim 1.

The invention also relates to a stored energy indicator mechanism according to claim 6.

The invention also relates to an integrally detachable differential gear assembly according to claim 16.

The invention also relates to a timepiece movement including at least one such power source and/or at least one such energy storage indicator.

The invention also relates to a watch or timepiece comprising at least one such power source and/or at least one such stored energy indicator mechanism.

Drawings

Other features and advantages of the present invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:

fig. 1 shows a schematic cross-section through the pivot axis of a timepiece power source having a barrel including a coaxial ball differential for displaying the residual stored energy on an indicator controlled by an output wheel which is a wheel acting as a cage for the balls of the differential, according to the invention.

Fig. 2 shows in a similar way an energy storage indicator based on the mechanism of fig. 1, with a winding wheel for the transmission of motion between the ratchet wheel and the differential disk, which acts as the first input device of the ball differential, the second input device being formed by the actual barrel.

Fig. 3 shows in a similar way an energy storage indicator based on the mechanism of fig. 1, with a planetary winding wheel for the transmission of motion between the ratchet wheel and the differential disk, which acts as the first input device of the ball differential, the second input device being formed by the actual barrel.

Figure 4 is a block diagram showing a watch comprising a movement according to the invention, incorporating a stored energy indicator, a power source and a coaxial ball differential.

Fig. 5 shows, in a similar but more schematic way to fig. 1 to 3, a timepiece power source with a barrel comprising a coaxial spherical aberration mechanism according to the invention, in which the ratchet directly forms the cover of the barrel.

Fig. 6 shows, in a similar manner to fig. 1 to 3, a partial view of another variant of the energy storage indicator, which comprises an integrally detachable differential subassembly.

Fig. 7 shows a schematic perspective view of the differential subassembly, seen from the upper side opposite to the lower side from which the balls protrude.

Figure 8 shows a schematic perspective view of the upper surface of the arbour and barrel arranged to receive the differential subassembly of figure 7.

Detailed Description

The invention relates to an energy storage display device for a mechanical timepiece, in particular a wristwatch, comprising at least one power source formed by a main barrel.

Swiss patent application CH 01102/14 and european patent application EP 1417777.5 of the same applicant disclose a charge indicator for a timepiece for the display of charge indications of a plurality of accumulators, each accumulator comprising an indicator cooperating with an input device of a differential mechanism comprised in the charge indicator, and wherein an output device of the differential mechanism cooperates with means for the display of the total charge of the plurality of accumulators.

More specifically, in this prior art, the differential gear comprises a hub driving a carrier plate carrying balls in contact with both a first input plate and a second input plate mounted in a freely rotating manner on the hub under the action of friction exerted by one or more springs. The hub is also integral with an output device in the form of a wheel which meshes with an intermediate plate contained in an input wheel set pivoting about a fourth pivot axis, the intermediate plate being coaxial with and integrally pivoting with a pinion engaging an input plate of a stored energy display mechanism which is coaxial with and integrally pivoting with a spindle arranged to carry a display element such as a pointer, disc or the like.

The invention described below relates to various subjects with common creativity: a power source including a barrel, an additional mechanism designed for low-cost conversion of the power source to add an energy storage display function thereto, or an independent energy storage mechanism including the power source.

The invention is described only in a simple example of a power source with a single barrel, but the person skilled in the art will know how to extend it to a timepiece comprising a plurality of barrels, in particular with reference to the documents cited above.

In a first variant, the invention relates to a timepiece power source 10 comprising a barrel. The barrel is of conventional type, pivoting about an arbour 11, containing a mainspring mounted between the barrel and the arbour 11, the arbour 11 carrying a ratchet 21 for driving the integral rotation of the arbour.

The power source 10 comprises a differential gear 20, which is coaxial with the barrel along its pivot axis D (also the axis of the arbour 11) and whose first input is driven indirectly by a ratchet 21 and whose second input is the barrel. The output of the differential gear 20 is a pivoting output wheel 23, the output wheel 23 being coaxial with the spindle 11 and arranged to form a stored energy indicator or to drive a stored energy indicator mechanism 50, particularly but not exclusively, by means of a gear train 51 or similar device to drive the stored energy indicator mechanism 50.

In a preferred, very economical embodiment shown in the figures, the differential gear 20 comprises a ball 25 which cooperates with the upper surface 13 of the barrel and with the lower surface 26 of the differential disc 22. The differential disk 22 is arranged to pivot on the spindle 11 coaxially with the spindle 11, the differential disk 22 being connected to the ratchet wheel 21 by a friction mechanism 24 and forming a first input device. These balls 25 drive the housings (housings) included in the output wheel 23 forming a cage (cage) when they rotate. The lower surface 26 is arranged on the upper surface side of the barrel.

More specifically, the barrel is formed in a conventional manner by a drum 14 provided with a toothing and by a cover 12 which together enclose the mainspring. In the construction of the barrel assembly, the ratchet 21 is opposite the cover 12, as seen in the figures, or the ratchet 21 is opposite the barrel wheel 14.

The first input for the winding function is indirectly driven by the ratchet 21, and the second input for the unwinding function is formed by the cover 12 or by the drum 14. The balls 25 cooperate on the one hand with the upper surface 13 of the cover 12 or the upper surface of the barrel wheel 14 and on the other hand with the lower surface 26 of the differential disc 22.

More specifically, the friction mechanism 24 is a spring provided between the ratchet 21 and the differential wheel 22.

In a second variant, the invention relates to a stored energy indicator mechanism 100 for displaying the energy storage of a timepiece power source 10, comprising a barrel formed by a barrel 14 provided with a toothing and a cover 12, the barrel 14 and the cover 12 together enclosing a mainspring mounted between said barrel and a barrel arbour 11 about which the barrel pivots, the barrel arbour 11 carrying a driving ratchet 21 external to the barrel and opposite to the cover 12 or barrel 14 and pivoting integrally with this ratchet 21. This is an additional mechanism that can be simply added to an existing barrel assembly provided that it is pre-set for this purpose (by suitable machining of barrel spindle 11), or that can be added to an existing barrel assembly in which barrel spindle 11 has been replaced by a spindle suitable for receiving charge indicator mechanism 100.

The mechanism 100 thus includes a greatly reduced number of components, each having a lower unit cost. The mechanism 100 comprises a ball differential mechanism 20, the ball differential mechanism 20 being coaxial with the barrel and comprising a subassembly arranged to be inserted axially between the cover 12 or barrel 14 and the ratchet 21. The subassembly includes:

a differential disc 22 arranged to pivot coaxially with the spindle 11, said differential disc 22 being arranged between:

on the upper side, a friction drive arrangement 24 arranged for relative driving between the differential disc 22 and the ratchet wheel 21,

-and, on the lower side,

an output wheel 23 arranged to pivot coaxially with the spindle 11 and forming a cage for holding balls 25 also included in the subassembly,

the balls 25 are arranged to roll between the lower surface 26 of the differential disc 22 and the upper surface 13 of the cover 12 or of the barrel wheel 14,

and wherein the output wheel 23 is arranged to form or drive a stored energy indicator 51 of the power source 10.

Naturally, stored energy indicator mechanism 100 may incorporate a power source 10 as described above.

The transmission of the movement from the ratchet wheel 21 to the differential wheel 22 must follow the direction of pivoting and may require a certain gear reduction ratio: due to the principle of the ball differential gear, the gear reduction ratio is 2.

In a third variation, one non-limiting example of which is shown in FIG. 2, the stored energy indicator mechanism 100 includes a base plate 2 that carries a power source 10. The bottom plate 2 carries an intermediate train 30 for driving the differential, which intermediate train 30 meshes with the ratchet wheel 21 and an intermediate train 40 for the differential, which intermediate train 40 is also carried by the bottom plate 2 and meshes with the differential disc 22.

The intermediate drive train 30 for the differential gear comprises an intermediate drive pinion 32 for the differential gear, which carries an intermediate drive wheel 31 for the differential gear, which intermediate drive wheel 31 is in direct mesh with the ratchet wheel 21. The ring gear 33 of the intermediate drive pinion 32 for the differential gear meshes with the ring gear 42 of the intermediate differential wheel 41.

In a fourth variation shown in fig. 3, the stored energy indicator mechanism 100 includes a base plate 2 carrying a power source 10. The base plate 2 comprises at least two pivots 60, each pivot 60 carrying a pivoting member 61 mounted to rotate freely and having a ring gear 62, the ring gear 62 meshing on the one hand with an external ring gear comprised in the differential disc 22 and on the other hand with an internal ring gear 210 comprised in the ratchet 21. However, this fourth variant with planetary winding is more expensive than the third variant with intermediate winding.

In view of the fact that most of the components contained therein are similar to those given above, fig. 5 shows, in a very simplified manner, a fifth variant with advantageously reduced axial space requirements, in which the ratchet 21 forms the barrel cover directly and there is naturally play (not shown in the figures) between the ratchet 21 and the barrel wheel 14. Here, the ball 25 cooperates with the upper surface of the barrel wheel 14. The ratchet 21 comprises a ring gear 211 which is engaged with the differential disc by means of a special gear train. For example, in fig. 5, the ring gear 211 cooperates with the first ring gear 72 of the intermediate ratchet 71, the second ring gear 73 of the intermediate ratchet 71 engages with the ring gear 75 of the intermediate commutator 74, and the ring gear 75 of the intermediate commutator 74 also meshes with the ring gear 220 of the differential disc 22. The friction means 24 thus rest directly on the base plate 2. Naturally, the driving of the gear train by means of the barrel wheel 14 must occur in another peripheral region of the barrel.

Fig. 6 shows a sixth variation, which includes a differential subassembly 50 that can be integrally disassembled.

The differential subassembly 50 is completely assembled on a first stepped ring 51, the first stepped ring 51 being mounted so as to be free to rotate axially on the bearing surface 112 of the spindle 11 on which the first stepped ring 51 is mounted. The first outer shoulder 52 of the first stepped ring 51 carries the output wheel 23 of the differential gear, the output wheel 23 being mounted to rotate freely relative to the first stepped ring 51.

As previously mentioned, the output wheel 23 forming the cage comprises balls 25 cooperating with the upper surface 13 of the barrel wheel 14 and the lower surface 26 of the differential disc 22, inside the housing 231. Preferably, on the side facing the barrel wheel 14, these housings 231 are made with a neck at their lower aperture to enable the subassembly 50 to be handled without losing the ball 25. The neck may be obtained when the output wheel is punched, or by a light trimming operation or similar. After positioning the output wheel 23 provided with balls 25 against the first outer shoulder 52, the differential disc 22, which has been pressed against the second stepped ring, is mounted against a second outer shoulder 58 contained in said second stepped ring 56. This second stepped ring 56 is mounted so as to rotate freely on the first stepped ring 51, in particular in the non-limiting embodiment of fig. 6, the hole 57 of the second stepped ring 56 is free to pivot on the outer bearing surface 54 comprised in the first stepped ring 51.

Naturally, the second stepped ring 56 and the differential disk 22 can also be made as a single component, it being important that the ring gear of the ratchet 21 is sufficiently separated from the ring gear of the differential disk 22. In particular, the second step ring 56 enables the use of plates 22 manufactured by stamping, which are considerably cheaper than machined wheels.

The differential disc 22 bears against the ball 25.

The differential subassembly 50 is then covered by the ratchet 21, the ratchet 21 being pressed against the first step ring 51 and resting on the upper bearing surface 58 of the second step ring 56.

At this stage, the differential subassembly 50 can be handled as a single piece and can be reversed if desired, particularly by automated assembly means.

The spindle 11 advantageously comprises a driving structure 111, represented in a non-limiting manner by a flat portion in fig. 8, and arranged to cooperate with a complementary driving structure 511 included in the first step ring 51, as seen in fig. 7, for mutual rotational driving and for winding of the power source 10. Naturally, the rotational drive can be achieved by any means known to the person skilled in the art, directly or indirectly by means of a key or the like.

Fig. 6 also shows a friction mechanism 24, for example an elastic washer or the like, between the ratchet 21 and the base plate 2.

The friction pushes the ratchet wheel 21 and the second step ring 56 carrying the differential disc 22, which differential disc 22 thus still forms the first input means of the differential gear, the second input means being formed by the barrel wheel 14.

The invention thus also relates to a self-contained differential subassembly 50 arranged to be mounted on a timepiece arbour 11, forming an integrally removable subassembly and comprising a first stepped ring 51, the first stepped ring 51 being arranged to be mounted free to rotate axially on a bearing surface of the arbour 11 and to pivot integrally with said arbour 11; said first step ring 51 coaxially carries the output wheel 23, the output wheel 23 being mounted so as to rotate freely with respect to the first step ring 51, this output wheel 23 forming a cage for a plurality of balls 25, the balls 25 projecting at the lower end of said differential sub-assembly 50 and being arranged to roll on the revolving surface of the wheel set or barrel, this first step ring 51 directly or indirectly carrying the differential disc 22, this differential disc 22 also being mounted so as to rotate freely on the first step ring 51 and being frictionally mounted on the balls 25 on the side opposite to the projecting end of the balls 25 at the lower end, the ratchet wheel 21 being pressed onto the first step ring 51 for the frictional driving of the differential disc 22.

The invention also concerns a timepiece movement 200 including at least one such power source 10 and/or at least one such energy storage indicator mechanism 100.

The invention also relates to a watch 300 or timepiece comprising at least one such power source 10, and/or at least one such stored energy indicator mechanism 100.

In short, according to the invention, by coupling the ball differential gear directly to the barrel in a coaxial manner, a useful watch complex mechanism is provided at acceptable manufacturing costs, since only limited conversion operations are required and a small number of simple components are added.

With regard to the barrel, only the mandrel needs to be modified. It is no longer necessary to add a pinion integral with the cover or barrel wheel to drive the differential.

A significant amount of height is saved compared to a standard differential gear.

Since the differential gear is coaxial with the barrel, there is a significant space saving in the horizontal dimension.

The cover of the barrel (or barrel wheel, depending on the arrangement) acts directly as the input for unwinding.

The output wheel 23 of the differential gear cannot be driven directly through the transmission ratchet 21; in fact, since the ratchet wheel rotates in the same direction as the barrel, the differential output will only rotate in one direction. This is also the reason why the pivoting direction is changed in conjunction with the gear train according to the invention. The driving ratchet integral with the barrel arbour drives the differential disc through a simple kinematic connection, in particular a gear train, and is inserted with a commutator to return to the correct pivoting direction: this is the subject of the third and fourth variants, which respectively comprise a double gear train and a planetary gear train, which is somewhat more expensive but more compact than a double gear train. Regardless of which scheme is selected, the overall space savings remain significant compared to the prior art.

Claims (9)

1. A timepiece power source (10) comprising a barrel pivoted about a arbour (11) housing a mainspring mounted between a barrel wheel (14) of said barrel and said arbour (11), said arbour (11) carrying a ratchet wheel (21) for driving said arbour (11) and rotating integrally with said ratchet wheel (21), said power source (10) comprising a differential gear (20), a first input of said differential gear (20) being indirectly driven by said ratchet wheel (21) and a second input being said barrel wheel (14), an output of said differential gear (20) being a pivoted output wheel (23), said output wheel (23) being coaxial with said arbour (11) and being arranged to form or drive a stored energy indicator; said differential gear (20) comprising balls (25) driving housings of said output wheel (23) forming a cage, said balls (25) cooperating with an upper surface (13) of said barrel and with a lower surface (26) of a differential disc (22) arranged on the side of said upper surface (13) of said barrel wheel (14), said differential disc (22) being arranged to pivot on said arbour (11) and coaxial with said arbour (11), said differential disc (22) being connected to said ratchet wheel (21) or to a bottom plate (2) by means of a friction mechanism (24) and forming said first input means, characterized in that said ratchet wheel (21) is incorporated in said barrel to form a cover of said barrel, and in that said differential disc (22) is connected to a bottom plate (2) by means of a friction mechanism (24).

2. Timepiece power source (10) according to claim 1, wherein the ratchet wheel (21) comprises a ratchet ring gear (211) meshing with a ring gear (220) of the differential disc (22) via a gear train, the ratchet ring gear (211) cooperating with a first ring gear (72) of an intermediate ratchet (71), a second ring gear (73) of the intermediate ratchet (71) meshing with an intermediate ring gear (75) of an intermediate commutator (74), this intermediate ring gear (75) also meshing with the ring gear (220) of the differential disc (22).

3. A timepiece power source (10) comprising a barrel pivoted about a arbour (11) and housing a mainspring mounted between a barrel wheel (14) of the barrel and the arbour (11), the arbour (11) carrying a ratchet wheel (21) for driving the arbour (11) and rotating integrally with the ratchet wheel (21), the power source (10) comprising a differential gear (20), a first input of the differential gear (20) being indirectly driven by the ratchet wheel (21) and a second input being the barrel, an output of the differential gear (20) being a pivoted output wheel (23), the output wheel (23) being coaxial with the arbour (11) and being arranged to form or drive a stored energy indicator (51); said differential gear (20) comprising balls (25) driving housings of said output wheel (23) forming a cage, said balls (25) cooperating with an upper surface (13) of the barrel and with a lower surface (26) of a differential disc (22) arranged on the side of said upper surface (13) of the barrel, said differential disc (22) being arranged to pivot on said arbour (11) and coaxial with said arbour (11), said differential disc (22) being connected to said ratchet (21) or to a bottom plate (2) by means of a friction mechanism (24) and forming said first input means, characterized in that said differential gear (20) is a differential subassembly (50), said differential subassembly (50) being removable in one piece and comprising a first step ring (51), said first step ring (51) being arranged to rotate freely axially on a bearing surface of said arbour (11) and to pivot in one piece with said arbour (11), -the first step ring (51) carries the output wheel (23) mounted so as to rotate freely with respect to the first step ring (51), the first step ring (51) also carrying, directly or indirectly, the differential disc (22) also rotating freely on the first step ring (51); the differential disk (22) bears against the balls (25), and the ratchet wheel (21) is pressed onto the first step ring (51) for frictional driving of the differential disk (22).

4. Timepiece power source (10) according to claim 3, wherein the ratchet (21) is external to the barrel, the barrel comprising a barrel wheel (14) provided with a toothing and a cover (12), the ratchet (21) being opposite the cover (12) or the barrel wheel (14), the differential gear (20) being arranged to be axially interposed between the cover (12) or the barrel wheel (14) and the ratchet (21).

5. Timepiece power source (10) according to claim 3 or 4, wherein the power source (10) comprises a base plate (2), the base plate (2) carrying a first intermediate train (30) for driving the differential gear, the first intermediate train (30) meshing with the ratchet wheel (21) and a second intermediate train (40) for the differential gear, the second intermediate train (40) also being carried by the base plate (2) and meshing with the differential disk (22).

6. A timepiece power source (10) comprising a barrel pivoted about a arbour (11) and housing a mainspring mounted between a barrel wheel (14) of the barrel and the arbour (11), the arbour (11) carrying a ratchet wheel (21) for driving the arbour (11) and rotating integrally with the ratchet wheel (21), the power source (10) comprising a differential gear (20), a first input of the differential gear (20) being indirectly driven by the ratchet wheel (21) and a second input being the barrel, an output of the differential gear (20) being a pivoted output wheel (23), the output wheel (23) being coaxial with the arbour (11) and being arranged to form or drive a stored energy indicator (51); said differential gear (20) comprising balls (25) driving receptacles of said output wheel (23) forming a cage, said balls (25) cooperating with an upper surface (13) of said barrel and with a lower surface (26) of a differential disc (22) arranged on the side of said upper surface (13) of said barrel wheel (14), said differential disc (22) being arranged to pivot on said arbour (11) and coaxially to said arbour (11), said differential disc (22) being connected to said ratchet wheel (21) or to a bottom plate (2) by means of a friction mechanism (24) and forming said first input means, characterized in that said power source comprises a bottom plate (2) carrying said power source (10), said bottom plate (2) comprising at least two pivots (60) each carrying a freely mounted pinion (61), said pinions (61) comprising a toothing (62), the ring gear (62) meshes on the one hand with an external ring gear contained in the differential disk (22) and on the other hand with an internal ring gear (210) contained in the ratchet wheel (21).

7. A differential gear assembly (50) arranged to be mounted on the arbour (11) of a timepiece, characterized in that it forms an integrally detachable differential sub-assembly comprising a first step ring (51), said first step ring (51) being arranged to be mounted free to rotate axially on a bearing surface of the arbour (11) and to pivot integrally with said arbour (11), said first step ring (51) coaxially carrying an output wheel (23) mounted free to rotate with respect to said first step ring (51), said output wheel (23) forming a cage for a plurality of balls (25), said balls (25) projecting at a lower end of said differential sub-assembly and being arranged to roll on a surface of revolution of a wheel set or of a barrel, said first step ring (51) directly or indirectly carrying a differential disc (22), the differential disc (22) is also mounted to rotate freely on the first step ring (51) and is frictionally mounted on the balls (25) on the side opposite the end of the balls (25) projecting at the lower end, a ratchet wheel (21) being press-fitted on the first step ring (51) for frictional driving of the differential disc (22).

8. Timepiece movement (200) comprising at least one power source (10) according to any one of claims 1 to 7.

9. Watch (300) or timepiece comprising at least one power source (10) according to any one of claims 1 to 7.