HK1213644B - Timepiece barrel - Google Patents

Description

Clock barrel

Technical Field

The invention concerns a timepiece barrel intended to be pivotally assembled between a bottom plate and a bridge and comprising at least one spring housed between a pivoting barrel wheel and a cover and hooked at its outer end and its inner end between said barrel wheel and a arbour, said arbour pivoting integrally with a ratchet about a pivot axis, said barrel comprising a single-piece sub-assembly coaxial with said pivot axis and comprising at least said ratchet and/or said arbour about a hub.

The invention also concerns a timepiece movement comprising at least one bottom plate and including a bridge and a barrel of this type.

The invention also relates to a watch comprising a movement of this type.

The present invention relates to the field of horological mechanisms, and more particularly to a mainspring barrel, striking barrel or similar type of energy storage mechanism.

Background

In order to improve the power reserve by increasing the number of turns of the mainspring fixed at its inner end to a core formed by a generally cylindrical arbour or by a more solid hub, one solution consists in reducing the diameter of the barrel arbour and of the relative hub, so as to increase the space available for the mainspring inside said barrel wheel.

The ratio of the core radius to the thickness of the balance spring is generally comprised between 10 and 20, the invention proposes to reduce this ratio to below 10, preferably in the range between 5 and 10.

The size cannot be set according to the grass rate; if the diameter of the core is too small, there is a risk of damage.

In a traditional barrel construction, the ratchet is mounted axially on the barrel arbour or core by means of a square, wherein the ratchet is usually fixed by an axial screw. The dimensions of the screw and the square thus define the minimum diameter of the pivot shoulder. The step connected to the pivot shoulder limits the axial play/clearance (shake) of the core or arbor relative to the base plate or splint carrying the gemstone or similar element.

In particular, merely reducing all dimensions is not sufficient, since the cross section of the material is then insufficient to guarantee fatigue resistance.

The problem is therefore to coordinate the smallest possible diameter to allow the largest possible energy reserve and the rigidity of the ratchet drive.

United states patent application US 804728A in the name of JOHNSON describes a barrel whose arbour carries a threaded hub, which hub comprises a mainspring. Two parts are therefore necessary for the internal retention of the spring. The drum is guided by jewel bearings which are not integral with the mandrel. The winding ratchet wheel is positioned on the other side of the barrel clamp plate. The portion of the square carrying the drive ratchet is not formed by the flange, but by the end of the arbour projecting beyond said jaws on the opposite side of the drum. .

United states patent application US 168581a published 1875 in the name of Potter discloses a barrel with a substantially smooth arbor which pivots at its ends between two jaws on either side of a bottom plate in which the barrel is embedded and which forms a cover for a barrel wheel. The arbour carries a hollow fusee which supports a wheel and to which the inner end of the spring is hooked. When the spring is pressed against the homodromous cone wheel, the mandrel bears the barrel wheel, and the outer end part of the spring is hooked on the barrel wheel. The arbour then carries a ratchet wheel which abuts on a small step of the arbour and is restrained underneath one of the side jaws.

French patent application FR 2329000a1 in the name of ETA discloses a barrel with a arbour having a non-cylindrical shaft, the hooks for hooking the spring being constrained in a recess delimited by a geometric cylinder defined by an upper and a lower bearing surface of the shaft.

Swiss patent application CH 83330a in the name of BEAULIEU WATCH CO describes a barrel without a lid, which barrel comprises a core screwed onto a mandrel. The drum is loosely fitted to the mandrel between the bearing surface of the mandrel and the core. Here again, two parts are required for internal retention of the spring.

French patent application FR 2210784a1 in the name of ETA discloses a barrel with a arbour comprising a longitudinal groove for hooking the spring.

Swiss patent application CH 15286A published in 1898 in the name of DANASINO discloses a barrel with a smooth arbor carrying a hollow fusee comprising a ratchet. The hollow fusee has two shoulders that receive the barrel wheel and the cap. The cross section of the mainspring increases gradually from its outer end toward its inner end.

United states patent application US 1561673a, published 1925 in the name of ULERY, discloses a barrel with a spindle, which barrel comprises a collar which serves as a support for a gear wheel driving a barrel wheel. The spindle comprises at its opposite ends two housing cavities, one of which receives a pin for guiding the spindle in a bearing received in the bottom plate and holding the end of the spindle in the bearing, and the other of which receives a fixed conical peg having a similar bearing surface for guiding over in the bridge plate and having a ratchet drive square at its distal end.

European patent application EP 2570864a1 in the name of BLANCPAIN discloses a barrel with a core which in turn comprises means for fixing a ratchet and/or a first pivot bearing in a bottom plate; a pivotally supported portion for the barrel wheel; a collar projecting from said bearing portion and bearing on the inner surface of the barrel wheel facing the spring; a receiving surface radially set back from the collar; a pivoting bearing receding from said receiving surface in the radial direction and for closing the cover of the barrel; and a second pivotally supported portion in the base plate.

Disclosure of Invention

The present invention proposes to improve the design of known barrels to achieve a large power reserve by achieving a high level of rigidity, in particular with respect to the ratchet, while maintaining a reduced number of components and acceptable manufacturing costs or preferably more economical costs than the known barrels.

The invention therefore concerns a timepiece barrel for pivotal assembly between a base plate and a bridge, and including at least one spring housed between a pivoting barrel wheel and a cover and hooked at its outer end and at its inner end between the barrel wheel and a arbour, the arbour pivoting integrally with a ratchet about a pivot axis, the barrel including a single-piece subassembly coaxial with the pivot axis and including at least the ratchet and/or the arbour about a hub, characterized in that the hub includes means for guiding the rotation of the barrel wheel and means for guiding the pivoting of the barrel in the bridge, and in that means for limiting the axial shake/play (shake) of the barrel wheel relative to the bridge are defined via a lower shoulder on the barrel wheel side and an upper shoulder on the bridge plate side, in addition, the arbour comprises means for guiding the barrel in the bottom plate and means for guiding the cap when it is guided on the barrel, and the arbour directly carries the inner end of the spring, wherein the single-piece subassembly comprises the ratchet and the hub, the hub defining inside it a tubular portion comprising an outer bearing surface on which the barrel is pivotally guided and a hole into which the arbour is pushed to pivot integrally with the hub.

According to a feature of the invention, the single-piece subassembly pivots on an upper bearing surface in a jewel bearing of or contained in the bridge and comprises an upper shoulder whose travel is limited by a lower surface of the bridge or of the jewel bearing, the ratchet being interposed between the upper and lower shoulders of the single-piece subassembly on the hub, the lower shoulder limiting the travel of the upper surface of the barrel wheel, the barrel wheel pivoting in cooperation with a cylindrical bearing surface of the hub through a hole contained therein.

According to another feature of the invention, the axial wobble of the drum is limited by the upper surface of the drum being in abutment against the ratchet wheel, the upper surface of the drum being limited by the lower shoulder of the one-piece subassembly, wherein the axial wobble of the ratchet wheel is limited by the upper surface of the one-piece subassembly being in abutment against the bridge, the upper surface of the one-piece subassembly being limited by the lower surface of the bridge or of a jewel bearing comprised in the bridge, wherein the axial wobble of the cover is limited by the lower surface of the cover being in abutment against the base plate, the lower surface of the cover being limited by the upper surface of the base plate or of a jewel bearing comprised in the base plate.

According to yet another feature of the invention, the balance spring is made of a multiphase cobalt-nickel-chromium based alloy comprising 44% to 46% cobalt, 20% to 22% nickel, 17% to 19% chromium, 4% to 6% iron, 3% to 5% tungsten, 3% to 5% molybdenum, 0 to 2% titanium, 0 to 1% beryllium, and having a young's modulus between 200 and 240GPa and a shear modulus between 80 and 100GPa, wherein the balance spring has a width-to-thickness ratio between 3 and 23, the ratio between the maximum radius of the bearing surface of the balance spring at the arbour and the thickness of the balance spring being between 3 and 9.

The invention also concerns a timepiece movement comprising at least one bottom plate and at least one bridge, and at least one barrel of this type.

The invention also relates to a watch comprising a movement of this type.

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 section through the pivot axis of a barrel according to a first related embodiment of the invention.

Fig. 2 shows a schematic section through the pivot axis of a barrel according to a second related embodiment of the invention.

Fig. 3 shows a schematic section through the pivot axis of the barrel according to the invention.

Fig. 4 shows a schematic block diagram of a timepiece comprising a movement which in turn comprises a barrel according to the invention.

Detailed Description

The present invention relates to the field of horological mechanisms, and more particularly to a mainspring barrel, striking barrel or similar type of energy storage mechanism.

The invention therefore concerns a timepiece barrel 1, barrel 1 being intended to be pivotally assembled between a bottom plate 9 and a bridge 5 and comprising at least one spring 7. This spring 7 is housed between the pivoting drum 6 and the cover 8 and is hooked between the drum 6 at its outer end and the arbour 3 at its inner end. The spindle 3 is mounted to pivot integrally with the ratchet 2 about a pivot axis D.

Barrel 1 comprises a single-piece subassembly 10 coaxial with arbour 3 and comprising at least ratchet 2 and arbour 3 around hub 4.

The single-piece subassembly 10 pivots on the upper bearing surface 13 in a bore 51 of the bridge 5 or of a jewel bearing 52 included in the bridge 5 and includes an upper shoulder 11, the travel of which is limited by a lower surface 53 of the bridge 5 or of the jewel bearing 52. The ratchet 2 is interposed between an upper shoulder 11 and a lower shoulder 12 of the one-piece subassembly 10 on the hub 4. Lower shoulder 12 limits the travel of upper surface 61 of drum 6. The drum 6 pivots in cooperation with the cylindrical bearing surface 41 of the hub 4 through a hole 62 contained in the drum.

The spindle 3 comprises a preferably cylindrical bearing surface 31, the diameter of which is preferably smaller than the diameter of the cylindrical bearing surface 41 of the hub 4. The arbour 3 carries the spring 7 on its bearing surface 31 or on a hook 32 included in the arbour 3 around this bearing surface 31, on which the spring 7 is fixed by friction or welding. The spindle 3 is pivotally mounted in a hole 91 of the base plate 9 or of a jewel bearing 92 included in the base plate 9. In a preferred embodiment, the bearing surface 31 extends in said hole 91 or in said jewel bearing 92 and forms a pivot surface.

Drum 6 carries a cover 8 which is preferably, but not necessarily, pivoted integrally with drum 6 and which has a hole 81, which hole 81 cooperates with bearing surface 31 of spindle 3. The travel of the lower surface 82 of the cover 8 is limited by the upper surface 93 of the base plate 9 or of a jewel bearing 92 accommodated in the base plate 9, wherein the hole 91 of the base plate 9 or of the jewel bearing 92 serves as a pivot bearing for the bearing surface 31 of the spindle 3.

Axial play of barrel wheel 6 is limited by upper surface 61 of barrel wheel 6 abutting up against ratchet 2, and upper surface 61 of barrel wheel 6 is limited by lower shoulder 12 of one-piece subassembly 10.

Axial wobble of the ratchet 2 is limited by the upper shoulder 11 of the single-piece subassembly 10 in an upper abutment with respect to the bridge 5, the upper shoulder 11 of the single-piece subassembly 10 being limited by the lower surface 53 of the bridge 5 or of a jewel bearing 52 comprised in the bridge 5.

Axial play of the cover 8 is limited by the lower surface 82 of the cover 8 in an upper abutment with respect to the base plate 9, the lower surface 82 of the cover 8 being limited by the upper surface 93 of the base plate 9 or of a jewel bearing 91 included in the base plate 9.

Mainspring can be made of a variety of materials: carbon steel, stainless steel "(Nwaflex clockwork) ", silicon, DLC (diamond-like carbon), quartz, glass, or the like. In a particular application, balance spring 7 is made of a multiphase cobalt nickel chromium based alloy comprising 44% to 46% cobalt, 20% to 22% nickel, 17% to 19% chromium, 4% to 6% iron, 3% to 5% tungsten, 3% to 5% molybdenum, 0 to 2% titanium, 0 to 1% beryllium and having a young's modulus between 200GPa and 240GPa and a shear modulus between 80GPa and 100 GPa. The spring 7 preferably has a width to thickness ratio of between 3 and 23, more particularly between 9 and 21.

Likewise, the maximum radius of the bearing surface 31 of the arbour 3, made of steel or stainless steel, for example 4C27A hardened steel (also known according to different standards as 1.4197, ASTM 420F or DIN X22CrMoNiS 131), with respect to the pivot axis D (without taking account of any additional thickness of the hooks 32) is less than nine times the maximum thickness of the balance spring 7. In particular, with the embodiment shown, it is possible to obtain a ratio of the maximum radius of the bearing surface 31 of the arbour 3 to the thickness of the balance spring 7 of between 3 and 9 and preferably between 4 and 6, preferably close to 5.

Fig. 1 to 3 illustrate 3 preferred but non-limiting variants, which are described in detail below:

first variant in fig. 1:

barrel 1 includes a one-piece subassembly 10 below bridge 5, which subassembly 10 includes ratchet 2, spindle 3 and hub 4.

The single-piece subassembly 10 pivots on the upper bearing surface 13 in a bore 51 of the bridge 5 or of a jewel bearing 52 of the bridge 5 and comprises an upper shoulder 11, the travel of which upper shoulder 11 is limited by a lower surface 53 of said bridge 5 or of said jewel bearing 52. The ratchet 2 is interposed between an upper shoulder 11 and a lower shoulder 12 of the one-piece subassembly 10 on the hub 4.

Lower shoulder 12 limits the travel of upper surface 61 of drum 6. The drum 6 pivots in cooperation with the cylindrical bearing surface 41 of the hub 4 through a hole 62 contained in the drum.

Arbour 3 has a smaller diameter than the diameter of hub 4 and carries a hook 32 for internally hooking spring 7, or carries spring 7 directly on bearing surface 31, spring 7 being fixed by friction or by welding or other means.

Drum 6 carries cover 8, cover 8 being integral with drum 6 and having hole 81, hole 81 cooperating with bearing surface 31 of spindle 3.

The travel of the lower surface 82 of the cover 8 is limited by the upper surface 93 of the base plate 9 or of a jewel bearing 92 accommodated in the base plate 9. The hole 91 of the base plate 9 or of the jewel bearing 92 serves as a pivot bearing for the bearing surface 31 of the spindle 3.

The single-piece subassembly 10 comprises a bearing surface 41 of the hub 4, the hub 4 pivoting in a bore 62 of the barrel wheel 6, the barrel wheel 6 likewise being pivotally mounted.

The one-piece subassembly 10 includes the bearing surface 31 of the spindle 3, which is pivoted in the bore 81 of the cover 8, the cover 8 likewise being pivotally mounted.

Above the ratchet 2, the one-piece subassembly 10 comprises in its upper part a bearing surface 13, which bearing surface 13 pivots in a hole 51 of the bridge 5 or of a jewel bearing 52 fixed in the bridge 5 as appropriate.

Below the cover 8, the single-piece subassembly 10 comprises in its lower part the bearing face 31 of the spindle 3, which spindle 3 pivots in a hole 91 of the bottom plate 9 or, where appropriate, of a jewel bearing 92 fixed in the bottom plate 9.

Axial play of drum 6 is limited by upper surface 61 of drum 6 abutting in an upper manner with respect to single-piece subassembly 10, upper surface 61 of drum 6 is limited by lower shoulder 12 of single-piece subassembly 10, lower shoulder 12 of single-piece subassembly 10 corresponding to the lower abutment of ratchet 2.

Axial wobble of the ratchet 2 is limited by the lower abutment of the upper shoulder 11 of the single-piece subassembly 10 with respect to the bridge 5, the upper shoulder 11 of the single-piece subassembly 10 being limited by the lower surface 53 of the bridge 5 or of the jewel bearing 52.

Axial play of the cover 8 is limited by the lower surface 82 of the cover 8 abutting above the base plate 9, and the lower surface 82 of the cover 8 is limited by the upper surface 93 of the base plate 9 or of the jewel bearing 91.

The core diameter is not limited by any other factors than the resistance of the material to shear stress, as is the diameter of the mandrel 3, which allows to produce very small mandrel diameters and to obtain a very favourable K-factor.

Second variant of fig. 2:

barrel 1 comprises a single-piece subassembly 10 below bridge 5, which single-piece subassembly 10 comprises spindle 3 and hub 4. The one-piece subassembly 10 receives the ratchet 2 abutting the shoulder 15, the ratchet 2 being mounted on a rivet 16 of the hub 4 to pivot integrally with the one-piece subassembly 10.

The single-piece subassembly 10 pivots on the upper bearing surface 13 in a bore 51 of the bridge 5 or of a jewel bearing 52 of the bridge 5, and the hub 4 comprises an upper shoulder 11, the travel of which is limited by a lower surface 53 of the bridge 5 or of the jewel bearing 52. The ratchet 2 is contained between the upper and lower shoulders 11, 12 of the hub 4 of the single-piece subassembly 10.

Lower shoulder 12 limits the travel of upper surface 61 of drum 6. Barrel wheel 6 pivots through aperture 62 in cooperation with cylindrical bearing surface 41 of hub 4.

Arbour 3 has a smaller diameter than the diameter of hub 4 and carries a hook 32 for internally hooking spring 7, or carries spring 7 directly on bearing surface 31, spring 7 being fixed by friction or by welding or other means.

Drum 6 supports cover 8, cover 8 being integral with drum 6 and having hole 81, hole 81 cooperating with bearing surface 31 of spindle 3.

The travel of the lower surface 82 of the cover 8 is limited by the upper surface 93 of the base plate 9 or of a jewel bearing 92 accommodated in the base plate 9. The hole 91 of the base plate 9 or of the jewel bearing 92 serves as a pivot bearing for the bearing surface 31 of the spindle 3.

The single-piece subassembly 10 comprises a bearing surface 41 of the hub 4, the hub 4 pivoting in a bore 62 of the barrel wheel 6, the barrel wheel 6 likewise being pivotally mounted.

The one-piece subassembly 10 comprises the bearing surface 31 of the spindle 3, the bearing surface 31 being pivoted in the bore 81 of the cover 8, the cover 8 likewise being pivotally mounted.

Above the ratchet 2, the one-piece subassembly 10 comprises in its upper part a bearing surface 13, which bearing surface 13 pivots in a hole 51 of the bridge 5 or of a jewel bearing 52 fixed in the bridge 5.

Below the cover 8, the single-piece subassembly 10 comprises in its lower part a bearing face 31 of the spindle 3, the bearing face 31 pivoting in a hole 91 of the base plate 9 or of a jewel bearing 92 fixed in the base plate 9.

This variant has three axial shake correction mechanisms.

Axial wobble of the barrel wheel 6 is limited by the lower abutment of the upper surface 61 of the barrel wheel 6 with respect to the hub 4, the upper surface 61 of the barrel wheel 6 being limited by the lower shoulder 12 of the hub 4 of the one-piece subassembly 10.

Axial play of the hub 4 is limited by the lower abutment of the upper shoulder 11 of the hub 4 with respect to the bridge 5, the upper shoulder 11 being limited by the lower surface 53 of the bridge 5 or of the jewel bearing 52.

Axial play of the cover 8 is limited by the lower surface 82 of the cover 8 abutting above the base plate 9, the lower surface 82 being limited by the upper surface 93 of the base plate 9 or of the jewel bearing 92.

In addition to the resistance of the material to shear stresses, the diameter of the hub at the drum is not limited by any other factor, as is the diameter of the arbour 3, which allows to produce a very small arbour diameter and to obtain a very favourable K factor.

Third variant of fig. 3: this third variant comprises, in the bottom plate, a guiding spindle fitted into a hub integral with the ratchet, wherein the hub forms a guide in the bridge; this variant allows assembly between the bridge and the bottom plate, followed by the attachment of the spindle.

Barrel 1 includes a one-piece subassembly 10 below bridge 5, which subassembly 10 contains ratchet 2 and hub 4. The hub 4 defines, internally, a tubular portion comprising an outer bearing surface 41 and a housing cavity or bore 45, the spindle 3 being pushed into the housing cavity or bore 45 and then pivoting integrally with the hub 4.

The spindle 3 can therefore be very simple, in particular comprising a single cylindrical bearing surface 31 and a hook 32, which can therefore be machined easily and economically.

The single-piece subassembly 10 pivots on the upper bearing surface 13 in a bore 51 of the bridge 5 or of a jewel bearing 52 of the bridge 5 and includes an upper shoulder 11, the travel of which upper shoulder 11 is limited by a lower surface 53 of the bridge 5 or of the jewel bearing 52. The ratchet 2 is comprised between an upper shoulder 11 and a lower shoulder 12 of the single-piece subassembly 10, the lower shoulder 12 being adjacent to the tubular portion of the hub 4 and its cylindrical bearing surface 41.

Lower shoulder 12 limits the travel of upper surface 61 of drum 6. Barrel wheel 6 pivots through the engagement of aperture 62 with cylindrical bearing surface 41 of hub 4.

Arbour 3 has a smaller diameter than the diameter of hub 4 and carries a hook 32 for internally hooking spring 7, or carries spring 7 directly on bearing surface 31, spring 7 being fixed by friction or by welding or other means.

Drum 6 carries cover 8, cover 8 being integral with drum 6 and having hole 81, hole 81 cooperating with bearing surface 31 of spindle 3.

The stroke of the lower surface 82 of the cover 8 is limited by the base plate 9 or the upper surface 93 of the jewel bearing 92 accommodated in the base plate 9. The hole 91 of the base plate 9 or of the jewel bearing 92 serves as a pivot bearing for the bearing surface 31 of the spindle 3.

The single-piece subassembly 10 comprises a bearing surface 41 of the hub 4, the hub 4 pivoting in a bore 62 of the barrel wheel 6, the barrel wheel 6 likewise being pivotally mounted.

The spindle 3 comprises a bearing surface 31, the bearing surface 31 being pivoted in a hole 81 of the cover 8, the cover 8 likewise being pivotally mounted.

Above the ratchet 2, the one-piece subassembly 10 comprises in its upper part a bearing surface 13, which bearing surface 13 pivots in a hole 51 of the bridge 5 or of a jewel bearing 52 fixed in the bridge 5.

Below the cover 8, the spindle 3 comprises in its lower part a bearing face 31, the bearing face 31 pivoting in a hole 91 of the bottom plate 9 or a fixed jewel bearing 92 of the bottom plate 9.

Axial play of barrel wheel 6 is limited by the lower abutment of upper surface 61 of barrel wheel 6 against ratchet 2, and upper surface 61 of barrel wheel 6 is limited by lower shoulder 12 of one-piece subassembly 10, lower shoulder 12 corresponding to the lower abutment of ratchet 2.

The axial wobble of the ratchet 2 is limited by the lower abutment of the upper shoulder 11 of the single-piece subassembly 10 with respect to the bridge 5, which upper shoulder 11 is limited by the lower surface 53 of the bridge 5 or of the jewel bearing 52.

Axial wobble of the cover 8 is limited by the lower surface 82 of the cover 8 abutting above the base plate 9, and the lower surface 82 of the cover 8 is limited by the base plate 9 or the upper surface 93 of the jewel bearing 92.

The hub diameter is not limited by any other factors than the resistance of the material to shear stress, as is the diameter of the mandrel 3, which allows a very small mandrel diameter to be produced and a very favourable K-factor to be obtained.

In a particular configuration, the invention therefore relates to a timepiece barrel 1, barrel 1 being intended to be pivotally assembled between a bottom plate 9 and a bridge 5 and comprising at least one spring 7, spring 7 being housed between a pivoting drum 6 and a cover 8. The spring 7 is hooked between the drum 6 at its outer end and the arbour 3 at its inner end, which pivots integrally with the ratchet 2 about the pivot axis D. Barrel 1 comprises a single-piece subassembly 10, single-piece subassembly 10 being coaxial with pivot axis D and comprising at least ratchet 2 and/or arbour 3 about hub 4. According to the invention, this hub 4 comprises means for guiding the rotation of barrel wheel 6 and means for guiding the pivoting of barrel 1 in bridge 5, and means for limiting the axial shake of barrel wheel 6 with respect to bridge 5 are defined via lower shoulder 12 on the barrel wheel 6 side and upper shoulder 11 on the bottom plate 9 side. In addition to the means for guiding cap 8 when cap 8 is guided on barrel 1, spindle 3 comprises means for guiding barrel 1 in bottom plate 9. Arbour 3 carries directly the inner end of spring 7. The single-piece subassembly 10 comprises a ratchet 2 and a hub 4, the hub 4 defining in its interior a tubular portion comprising an outer bearing surface 41 and a hole 45, the drum 6 being pivotally guided on the bearing surface 41, the spindle 3 being pushed into the hole 45 to pivot integrally with the hub 4.

In a further variant, very similar to the variant of figure 3, the spindle 3 comprises an externally threaded end portion which cooperates with an internal thread contained in the tubular portion of the hub 4, which end portion therefore replaces the hole 45.

In short, the first variant of fig. 1 is advantageous because the one-piece subassembly 10 combines the functions of a cap, ratchet, arbour and hub, without processing complexity other than the hook 32 for hooking the spring 7. There are three axial rocking mechanisms. This configuration has the advantage of no restriction on the diameter of the hub.

The second variation of fig. 2 differs in that the ratchet is riveted to the spindle, with three axial wobble corrections. There is also no limitation on the hub diameter here.

The third variant in fig. 3 is advantageous in so far as the hook 32 is inexpensively machined onto the spindle without the collar. The arbor is advanced (or screwed) into the ratchet wheel, and the barrel wheel is pivoted on the ratchet wheel tubular portion, with three axial shake correction mechanisms. There is also no limitation on the hub diameter here.

The invention also relates to a timepiece movement 100 comprising at least one bottom plate 9, a bridge 5 and a barrel 1 of this type.

The invention also relates to a watch 200 comprising a movement 100 of this type.

Claims (8)

1. Timepiece barrel (1) for pivotal assembly between a base plate (9) and a bridge (5) and comprising at least one spring (7) housed between a pivoting barrel wheel (6) and a cover (8) and hooked at its outer end and its inner end between the barrel wheel (6) and a arbour (3) which pivots integrally with a ratchet (2) about a pivot axis (D), said barrel (1) comprising a one-piece subassembly (10) coaxial with the hub pivot axis (D) and comprising at least the arbour (3) and the ratchet (2) about a hub (4), characterized in that said barrel (4) comprises means for guiding the rotation of the barrel wheel (6) and means for guiding the pivoting of the barrel (1) in the bridge (5) and via a lower shoulder (12) on the barrel wheel (6) side and an upper shoulder on the bridge (5) side 11) Defining means for limiting the axial oscillation of the barrel wheel (6) with respect to the bridge (5), wherein the arbour (3) comprises means for guiding the barrel (1) in the bottom plate (9) and means for guiding the cap (8) when the cap (8) is guided on the barrel (1), wherein the single-piece subassembly (10) comprises the ratchet (2) and the hub (4), which defines inside it a tubular portion comprising a cylindrical bearing surface (41) on which the barrel wheel (6) is pivotally guided, and a hole (45) into which the arbour (3) is pushed to pivot integrally with the hub (4).

2. Barrel (1) according to claim 1, characterized in that said single-piece subassembly (10) pivots on an upper bearing surface (13) in a hole (51) of said bridge (5) or of a jewel bearing (52) contained in said bridge (5) and comprises an upper shoulder (11) whose travel is limited by a lower surface (53) of said bridge (5) or of said jewel bearing (52), said ratchet (2) being interposed between said upper shoulder (11) and a lower shoulder (12) of said single-piece subassembly (10) on said hub (4), said lower shoulder (12) limiting the travel of an upper surface (61) of said barrel wheel (6), said barrel wheel (6) pivoting in cooperation with a cylindrical bearing surface (41) of said hub (4) through a hole (62) contained therein.

3. Barrel (1) according to claim 2, characterized in that said arbour (3) comprises a bearing surface (31) having a smaller diameter than the diameter of the cylindrical bearing surface (41) of said hub (4), said bearing surface (31) of said arbour carrying said spring (7) by: the spring (7) is fixed to the bearing surface (31) of the arbour by friction or welding, wherein the bearing surface (31) of the arbour pivots in a hole (91) of the base plate (9) or of a jewel bearing (92) included in the base plate (9).

4. Barrel (1) according to claim 1, characterized in that said barrel wheel (6) carries said cover (8) pivoted integrally with said barrel wheel (6) and having a hole (81) which cooperates with a bearing surface (31) of said arbour (3), wherein the travel of the lower surface (82) of said cover (8) is limited by the upper surface (93) of said bottom plate (9) or of a jewel bearing (92) housed in said bottom plate (9), the hole (91) of said bottom plate (9) or of jewel bearing (92) acting as a pivot bearing for said bearing surface (31) of said arbour (3).

5. Barrel (1) according to claim 1, characterized in that the axial wobble of the barrel wheel (6) is limited by the upper surface (61) of the barrel wheel (6) in an abutting manner with respect to the ratchet wheel (2), the upper surface (61) of the barrel wheel (6) is limited by the lower shoulder (12) of the one-piece subassembly (10), wherein the axial wobble of the ratchet wheel (2) is limited by the upper shoulder (11) of the one-piece subassembly (10) in an abutting manner with respect to the bridge (5), the upper shoulder (11) of the one-piece subassembly (10) is limited by the lower surface (53) of the bridge (5) or of a jewel bearing (52) comprised in the bridge (5), wherein the axial wobble of the cover (8) is limited by the lower surface (82) of the cover (8) in an abutting manner with respect to the base plate (9), the lower surface (82) of the cover (8) is limited by the upper surface (93) of the base plate (9) or of a jewel bearing (92) included in the base plate.

6. Barrel (1) according to claim 1, characterized in that the balance spring (7) is made of a multiphase cobalt-nickel-chromium based alloy comprising 44% to 46% cobalt, 20% to 22% nickel, 17% to 19% chromium, 4% to 6% iron, 3% to 5% tungsten, 3% to 5% molybdenum, 0 to 2% titanium, 0 to 1% beryllium and having a young's modulus between 200GPa and 240GPa and a shear modulus between 80GPa and 100GPa, wherein the balance spring (7) has a width-to-thickness ratio between 3 and 23, the ratio between the maximum radius of the bearing surface (31) of the arbour (3) for bearing the balance spring and the thickness of the balance spring (7) being between 3 and 9.

7. Timepiece movement (100) comprising at least one bottom plate (9), a bridge (5) and a barrel (1) according to any one of the preceding claims.

8. A watch (200) comprising a timepiece movement (100) according to claim 7.