HK1197840B - Timepiece barrel assembly having a small core diameter - Google Patents

Description

Timepiece barrel assembly with reduced core diameter

Technical Field

The invention concerns a timepiece barrel assembly including at least one barrel spring mounted at a first end and a second end between a barrel drum and a receiving surface contained in a barrel core coaxial with the barrel drum about a pivot axis.

The invention also concerns a timepiece movement including at least one barrel assembly of this type.

The invention also concerns a timepiece including at least one movement of this type and/or at least one barrel assembly of this type.

The present invention relates to the field of horology, and more particularly to an energy-storing barrel for powering a movement, a striking work, or other timepiece functions.

Background

In order to improve the energy reserve by increasing the number of revolutions of the mainspring, one solution consists in reducing the diameter of the barrel arbour/barrel and of the relative core, so as to increase the space available for the spring inside the barrel.

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

The size must not be too small; if the core diameter is too small, there is a risk of breakage.

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 means of an axial screw. Thus, the size of the screw and the spline defines the minimum diameter of the pivot shoulder. The step connected to the pivot shoulder limits the axial clearance of the spindle or core with respect to the main plate or bridge carrying the jewel (bearing) or similar element.

With a step limiting the axial play of the drum, the shoulder for guiding the pivoting of the drum on the arbour or core needs to have a larger diameter than the step. The dimensional chain required to maintain a minimum cross section of material results in very large dimensions that are difficult to reduce. In particular, simply reducing all dimensions is not sufficient, since the cross section of the material is not sufficient to ensure fatigue resistance.

Document CH319631 in the name of FELSA discloses a double barrel and a way of limiting the play of each barrel wheel. The clearance of the lower drum is limited at the upper side by the collar of the sleeve, which is pushed towards the shoulder of the barrel arbour by the nut screwed on the barrel arbour; and, the gap of the lower drum is limited on the lower side by the base of the core, which pivots integrally with the barrel arbour via a flat portion. The length of the lower shoulder of the barrel arbour and the length of the barrel tube determine the clearance of the barrel relative to these collars and the base surface.

Document US1110061 in the name of KIENZLE discloses a core that is removably mounted on the barrel arbour (in the pivoting direction); the core is supported on both the main and bridge plates, while the two shoulders of the core limit the travel of the drum and the cover.

Document US3564839 in the name of wutherich discloses a barrel comprising a thread on a bridge for supporting a barrel wheel, said barrel wheel having a tube. The cover is a pure metal plate located on the base plate without connection to the barrel arbour or barrel wheel. The barrel arbour comprises two shoulders, one of which rests on the core and the other of which is intended to cooperate in abutment with the barrel.

Document GB1162296 in the name of CITIZEN discloses a spring of variable thickness, but does not give any height characteristics relating to the spring.

Document CH341764 in the name of AUGE discloses a spring with strips of different widths welded to each other.

All these documents disclose barrel arbours having a hook for driving the spring, but do not disclose a pivoting barrel arbour for receiving the spring. These documents do not specifically discuss any recess in the barrel arbour or core in which the spring can be positioned. Certain patent documents disclose a balance spring whose stiffness is varied by varying its thickness or other parameters on the inner end coil; the geometry of the spring is not considered for determining the center of the spring.

Disclosure of Invention

Due to these physical constraints on the dimensions of the various components, a barrel structure must be envisaged which is different from the conventional structure just described.

The present invention contemplates several solutions to achieve the purpose of core diameter reduction.

One significant constraint is to ensure that the assembly can be disassembled in order to replace the mainspring or the entire barrel when necessary.

The various devices proposed by the present invention can be combined with each other to obtain the best results, depending on the available space, the position of the ratchet, the presence or absence of a cover for closing the barrel (although this function can also be performed by the ratchet).

A first solution consists in providing a solution for the gap between the barrel wheel and the cover by giving the spring a gap-adjusting function, in particular by providing the spring with projecting areas such as lugs, wider lamination zones, or the like, adding flanges or in a similar way by the spring. It is therefore possible to dispense with the shoulders for supporting the drum and the cover on the barrel arbour or on the core.

A second solution consists in forming the core from a plurality of portions, in particular two or three portions. This solution makes it possible in particular to form a core of smaller diameter than the pivoting diameter of the drum. Advantageously, the core is inserted through a hole in the drum. A mandrel or core formed of two or more parts facilitates the machining of the hooks for hooking the primary spring holes.

The core may comprise a conventional square or screw thread for driving the ratchet. Alternatively, in a second variant, the core may also comprise one or more diameter-adjusting washers or rings for guiding the core within the main and bridge plates, in a non-limiting manner.

Another solution consists in pressing a washer onto the core to adjust the drum-cover gap. The washer is mounted to prevent the bridge from being removed when it is desired to operate on the barrel.

A further solution consists in providing the pivoting of the drum and/or the cover in the bridge, instead of on the barrel arbour or core. Advantageously, both the drum and the cover pivot in the main bridge and the bridge.

The different variants proposed by the invention ensure ease of machining, assembly and disassembly, and control of the axial clearance between the components and with respect to the bridge.

In a particular aspect, the invention relates to a timepiece barrel assembly including at least one barrel spring mounted at a first end and a second end between a barrel drum and a receiving surface contained in a barrel core coaxial with said barrel drum about a pivot axis, characterized in that said barrel spring is made of a multiphase cobalt-nickel-chromium-based alloy comprising 44-46% cobalt, 20-22% nickel, 17-19% chromium, 4-6% iron, 3-5% tungsten, 3-5% molybdenum, 0-2% titanium, 0-1% beryllium and having a young's modulus between 200GPa and 240GPa and a shear modulus between 80GPa and 100GPa, and in that said barrel spring has a width ratio between 9 and 21, and in that said core made of steel or stainless steel has a maximum radius ratio with respect to said pivot axis of said barrel spring of a thickness between 9 and 21 9 times less than the maximum thickness and the barrel assembly comprises means on the spring or the barrel drum for limiting the longitudinal play between the barrel drum and the mainspring in the direction of the pivot axis.

According to a feature of the invention, said means for limiting the longitudinal play between said barrel and said spring are formed by at least one lug on at least one edge of said spring or by a peripheral recess included in said barrel at its maximum internal diameter, said peripheral recess being comprised between two inclined shoulders for peripheral retention and support of said spring.

The invention also concerns a timepiece movement including at least one barrel assembly of the above type for storing energy, having an input formed by a ratchet wheel mounted for integral rotation with the core or by a drum toothing mounted for integral rotation with the drum, and an output formed respectively by a drum toothing mounted for integral rotation with the drum or by a ratchet wheel mounted for integral rotation with the core.

The invention concerns a timepiece including at least one timepiece movement of the above type and/or at least one barrel assembly of the above type for storing energy, said barrel assembly having an input formed by a ratchet mounted for integral rotation with said core or by a drum toothing mounted for integral rotation with said drum, and an output formed respectively by a drum toothing mounted for integral rotation with said drum or by a ratchet mounted for integral rotation with said core.

Drawings

Other features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings, in which:

fig. 1 shows a schematic cross-sectional view of a timepiece barrel in a plane passing through its pivot axis.

Fig. 1A shows a schematic cross-sectional view of a barrel according to the invention in a plane passing through its pivot axis.

Fig. 1B shows a schematic sectional view of another barrel variant according to the invention in a plane passing through its pivot axis.

Figure 2 shows a schematic perspective view of a variant of the core according to the invention.

Fig. 3 shows a schematic perspective view of a variant of the core according to the invention comprising a recess for retaining the mainspring.

Figure 4 shows a schematic top view of the core of figure 2.

Figures 5A, 5B, 5C show respectively a schematic front view, a section view and a plan view of a spring with friction mounting, the ends of the spring being shown flattened.

Fig. 6A, 6B, 6C show respectively a schematic front view, a section view and a plan view of another type of spring with friction mounting, the ends of the spring being shown flattened.

Fig. 7 shows a schematic partial section of the barrel of the invention in a plane passing through the pivot axis, with the core having a particular arrangement in terms of the receiving surface in the spring.

Fig. 8 shows a schematic partial section of the right part of the barrel of the invention in a plane passing through the pivot axis, wherein the spring has lugs according to the invention, and fig. 8A shows a detail of the spring shown flattened.

Fig. 9 shows a schematic perspective view of a spring of the invention with a projecting, wider partial coil, and fig. 10 shows a detail of the spring.

Fig. 11 shows a schematic perspective view of a spring of the invention with protruding additional flanges, and fig. 12 shows a detail of the spring.

Fig. 13 shows a schematic partial section of the barrel of the invention in a plane passing through the pivot axis, the maximum diameter of the barrel having a particular arrangement in terms of the outer barrel-receiving surface.

Fig. 14 shows a block diagram of a timepiece movement including a barrel assembly according to the invention and a block diagram of a timepiece including a movement and a barrel assembly according to the invention.

15A, 15B, 15C show perspective views of different variants of cores according to the invention arranged for welding mainspring.

Fig. 16 shows a block diagram of a timepiece movement including a barrel assembly according to the invention and a block diagram of a timepiece including a movement and a barrel assembly according to the invention.

Detailed Description

The present invention relates to the field of horology, and more particularly to an energy-storing barrel for powering a movement, a striking work, or other timepiece functions.

The invention relates more particularly to a barrel for a mechanical watch with a reduced core diameter.

In a particular version, the invention relates to a timepiece barrel assembly 1, this barrel assembly 1 comprising at least one barrel mainspring 2. This spring 2 is conventionally mounted between drum 3 and a receiving surface 5 contained in a barrel core 4, at a first end 21 and a second end 22, barrel core 4 being coaxial with drum 3 about a pivot axis D.

According to the invention, the balance spring 2 is made of a multiphase cobalt-nickel-chromium based alloy comprising 44-46% cobalt, 20-22% nickel, 17-19% chromium, 4-6% iron, 3-5% tungsten, 3-5% molybdenum, 0-2% titanium, 0-1% beryllium and has a young's modulus between 200 and 240GPa and a shear modulus between 80 and 100 GPa.

Balance spring 2 has a width to thickness ratio of between 3 and 23, in particular between 9 and 21.

The maximum radius of the core 4 of steel or stainless steel with respect to the pivot axis D is less than 9 times the maximum thickness of the balance spring 2.

Barrel assembly 1 comprises means 6 on spring 2 or drum 3 for limiting the longitudinal play between drum 3 and spring 2 in the direction of pivot axis D.

In a particular variant, as shown in fig. 8 and 8A, spring 2 advantageously comprises at least one protruding area 23 arranged for abutting cooperation with inner surface 31 of drum 3 and/or with inner surface 71 of cover 7, said cover 7 and drum 3 defining a chamber 32 housing spring 2.

As shown in fig. 8A, in a first variant, this protruding area 23 comprises at least one lug 24 on at least one edge 27, 28 of spring 2. This protruding area 23 is arranged for cooperating with the inner surface 31 of barrel wheel 3 and/or with the inner surface 71 of cover 7, and preferably with both.

According to a particular feature of the invention, means 6 for limiting the longitudinal clearance between barrel 3 and spring 2 are therefore formed by at least one lug 24 on at least one edge 27, 28 of spring 2 or by a peripheral recess 36 included in barrel 3 at its maximum internal diameter, said peripheral recess 36 being comprised between two inclined shoulders 33, 34 for peripheral retention and support of spring 2.

In a preferred embodiment, as shown in fig. 1A and 1B, spring 2 is confined within a chamber 32 defined by drum 3 and cover 7, and spring barrel assembly 1 according to the invention comprises, not on core 4, means 6 for adjusting the longitudinal clearance between cover 7 and spring 2 in the direction of pivot axis D.

According to a particular feature of the invention, at least one lug 24 of spring 2 is arranged for abutting engagement with inner surface 31 of drum 3 and/or with inner surface 71 of cover 7, said cover 7 defining with drum 3a chamber 32 for housing spring 2.

According to a particular feature of the invention, in a further variant visible in fig. 9 or 10, this protruding area 23, or in particular this lug 24, comprises at least one coil of increased height of spring 2.

In another variant, visible in fig. 11 and 12, this protruding area 23, or in particular this lug 24, comprises at least one additional flange 26, this flange 26 having a height locally higher than the height of the coils of spring 2, and this flange 26 being fixed to the spring, for example by welding.

In the particular embodiment of fig. 13, barrel 3 comprises, on its maximum internal diameter, an external peripheral recess 36, said external peripheral recess 36 being between an upper collar 37 and a lower collar 38, the upper edge 27 and the lower edge 28 of said collars respectively carrying at an angle α two inclined shoulders 33 and 34 for the peripheral retention and support of spring 2. In a variant of this type, the means 6 for limiting the longitudinal clearance between barrel 3 and spring 2 are formed by an outer peripheral recess 36 included in barrel 3 at its maximum inner diameter, this peripheral recess 36 being comprised between two shoulders 33, 34 for the peripheral retention and support of spring 2.

The combination of the embodiments of figures 7 and 13 is easy and ensures a good hold of spring 2. In the preferred example, the spring has a protruding area 23, one side of protruding area 23 being fixed with respect to drum 3 and/or cover 7, which ensures perfect adjustment of the clearance.

In a variant, the peripheral recess 36 is cylindrical and has the same height as the spring 2, which is placed centrally between the shoulders 33, 34, which are flat and perpendicular to the pivot axis D.

According to another particular feature of the invention, peripheral recess 36 has a height less than that of spring 2, said spring 2 being supported centrally inclined between shoulders 33, 34, said shoulders comprising inclined planes facing each other so as to define a V-shaped support for edge surfaces 27, 28 incorporated in spring 2.

According to a particular feature of the invention, spring 2 is held elastically without hooking on receiving surface 5, which is a surface of revolution with respect to pivot axis D.

Fig. 2 and 3 show a core housed in a cladding having a radius R0 about axis D. Receiving surface 5 comprises a hook 41 for hooking the hole of spring 2; recess 52 allows spring 2 to be hooked and facilitates the machining of hook 41. The shoulders 43 and 44 are arranged for cooperating with jewel bearings mounted in a main or bridge plate receiving the movement of barrel assembly 1. The square 42 is arranged for hooking the ratchet 12. Shoulders 45 and 46 cooperate with hole 35 of drum 3 and hole 75 of cover 7, respectively.

In a particular embodiment, as shown in fig. 3, 15A, 15B, 15C, the receiving surface 5 is a surface that revolves about the pivot axis D. Preferably, this receiving surface is a contact surface for fixing spring 2, spring 2 being welded to core 4 by point 53 or along a section passing through point 53 preferably parallel to pivot axis D, as shown in fig. 15A, 15B, 15C.

In the example of fig. 15A, spring 2 is supported at point 53 on the cylindrical portion of core 4 having a smaller width. In the example of fig. 15B, spring 2 is supported on a point 53 on a flat portion tangent to one of shoulders 45 or 46 supporting drum 3 or cover 7, preferably to shoulder 45 intended to cooperate with hole 35 of drum 3. Fig. 15C shows the cylindrical bearing surface of spring 2, which is wider than that of fig. 15A and is partially merged with one of shoulders 45 or 46 for supporting drum 3 or cover 7, preferably with shoulder 45 intended to cooperate with hole 35 of drum 3. In the particular variant of fig. 15C, the spring receiving surface 5 has a spiral portion starting from the welding point 53 or from a welding section passing through the point 53 and parallel to the pivot axis D, so that after the first revolution the spring overlaps itself without causing any bending or breaking in gradient.

In the particular embodiment shown in fig. 3, the surface of revolution 5 is formed by a recess 8, this recess 8 having a height h between shoulders 91, 92 belonging to the collars 47, 48. This shoulders 91 and 92 define the maximum radius of the core 4 relative to the pivot axis D. Preferably, recess 8 is cylindrical and of the same height as spring 2, spring 2 being centrally located between shoulders 91, 92, said shoulders 91, 92 being flat and perpendicular to pivot axis D.

Advantageously, recess 8 has a depth P corresponding to twice the thickness of spring 2.

In another variant shown in fig. 7, the recess 8 has a height h less than the height of the spring 2, said spring 2 being supported centrally inclined between the shoulders 91, 92 of the upper and lower collars 47, 48. These collars 91 and 92 comprise inclined ramps facing each other at an angle α to define a V-shaped bearing for the edge surfaces 27 and 28 of the spring 2.

Fig. 1B shows an embodiment in which the drum has a shoulder 3A facing spring 2 and can be supported via bearing surface 3B on a bearing surface 4B comprised in core 4, and cover 7 has a shoulder 7A facing spring 2 and can be supported via bearing surface 7B on a bearing surface 4C comprised in core 4.

As seen in particular, but in a non-limiting manner, in the variant of figures 5A, 5B, 5C, 6A, 6B, 6C, barrel assembly 1 has spring 2 frictionally fixed to core 4, the end of spring 2 therefore preferably comprising a shoulder designed to keep the free end of spring 2 in an arcuate shape when the spring is wound.

In other embodiments, spring 2 and core 4 form a single-piece welded or soldered or similar spring-core subassembly. This embodiment is particularly advantageous, economical and very easy to assemble.

The invention also concerns a timepiece movement 100, said movement 100 including at least one barrel assembly 1 of the above-mentioned type for storing energy, said barrel assembly 1 having an input formed by a ratchet wheel 12 mounted for integral rotation with the core 4 or by a drum toothing 13 mounted for integral rotation with the drum 3, and an output formed respectively by a drum toothing 13 mounted for integral rotation with the drum 3 or by a ratchet wheel 12 mounted for integral rotation with the core 4.

The invention concerns a timepiece 1000 comprising at least one timepiece movement 100 and/or at least one barrel assembly 1 for storing energy, said barrel assembly 1 having an input formed by a ratchet wheel 12 mounted for integral rotation with a core 4 or by a drum toothing 13 mounted for integral rotation with a drum 3, and an output formed respectively by a drum toothing 13 mounted for integral rotation with a drum 3 or by a ratchet wheel 12 mounted for integral rotation with a core 4.

Claims (17)

1. Timepiece barrel assembly (1), said barrel assembly (1) comprising at least one barrel (2), said barrel (2) being mounted between a barrel (3) and a receiving surface (5) contained in a barrel core (4) at a first end (21) and a second end (22), said barrel core (4) being coaxial with said barrel (3) about a pivot axis (D), characterized in that said barrel is made of a multiphase cobalt-nickel-chromium based alloy comprising 44-46% cobalt, 20-22% nickel, 17-19% chromium, 4-6% iron, 3-5% tungsten, 3-5% molybdenum, 0-2% titanium, 0-1% beryllium and having a Young's modulus between 200GPa and 240GPa and a shear modulus between 80GPa and 100GPa, and the barrel has a width-to-thickness ratio between 9 and 21, and the maximum radius of the core (4) made of steel with respect to the pivot axis (D) is less than 9 times the maximum thickness of the barrel (2), and the barrel assembly (1) comprises means (6) on the barrel (2) or on the barrel (3) for limiting the longitudinal clearance between the barrel (3) and the barrel (2) in the direction of the pivot axis (D).

2. Barrel assembly (1) according to claim 1, characterized in that said means (6) for limiting the longitudinal clearance between the barrel (3) and the barrel (2) are formed by at least one lug (24) on at least one edge (27, 28) of the barrel (2) or by a peripheral recess (36) included in the barrel (3) on its maximum internal diameter, said peripheral recess (36) being comprised between two inclined shoulders (33, 34) for peripheral retention and support of the barrel (2).

3. A barrel assembly (1) according to claim 2, wherein said at least one lug (24) of the spring (2) is arranged for abutting cooperation with an inner surface (31) of the barrel wheel (3) and/or with an inner surface (71) of a cover (7), said cover (7) defining with the barrel wheel (3) a chamber (32) for housing the spring (2).

4. A barrel assembly (1) according to claim 3, wherein said lug (24) comprises at least one coil of increased height of said barrel (2).

5. A barrel assembly (1) according to claim 3, characterized in that said lug (24) comprises at least one additional flange (26), said additional flange (26) having a height locally higher than the height of the barrel (2) and being fixed to the barrel.

6. Barrel assembly (1) according to claim 2, characterized in that said means (6) for limiting the longitudinal clearance between the barrel wheel (3) and the spring (2) are formed by a peripheral recess (36) included in the barrel wheel (3) on its maximum internal diameter, said peripheral recess (36) being comprised between two shoulders (33, 34) for peripheral retention and support of the spring (2).

7. A barrel assembly (1) according to claim 6, characterized in that said peripheral recess (36) is cylindrical and of the same height as the barrel (2), said barrel being placed centrally between said shoulders (33, 34), said shoulders (33, 34) being flat and perpendicular to said pivot axis (D).

8. A barrel assembly (1) according to claim 6, characterized in that said peripheral recess (36) has a height smaller than the height of the barrel (2), said barrel (2) being supported centrally inclined between said shoulders (33, 34), said shoulders (33, 34) comprising slopes facing each other so as to define a V-shaped support for the edge surfaces (27, 28) incorporated in the barrel (2).

9. A barrel assembly (1) according to claim 1, wherein the barrel (2) is held elastically without hooking on the receiving surface (5), the receiving surface (5) being a surface of revolution revolving with respect to the pivot axis (D).

10. A barrel assembly (1) according to claim 9, wherein said receiving surface (5) is formed by a recess (8) comprised between two shoulders (91, 92) defining said maximum radius of said core (4) with respect to said pivot axis (D).

11. A barrel assembly (1) according to claim 10, wherein said recess (8) has a height less than the height of the spring (2), said spring (2) being supported centrally inclined between said shoulders (91, 92), said shoulders (91, 92) comprising inclined planes facing each other and defining a V-shaped support for the edge surfaces (27, 28) incorporated in the spring (2).

12. A barrel assembly (1) according to claim 1, wherein the barrel (2) is frictionally fixed to the core (4).

13. A barrel assembly (1) according to claim 1, wherein the spring (2) and the core (4) form a welded or soldered one-piece spring-core subassembly.

14. A barrel assembly (1) according to claim 1, wherein the core is made of stainless steel.

15. A timepiece movement (100), this timepiece movement (100) comprising at least one barrel assembly (1) according to any one of the preceding claims for storing energy, the barrel assembly (1) having an input formed by a ratchet wheel (12) mounted for integral rotation with the core (4) or by a drum toothing (13) mounted for integral rotation with the drum (3), and an output formed respectively by a drum toothing (13) mounted for integral rotation with the drum (3) or by a ratchet wheel (12) mounted for integral rotation with the core (4).

16. A timepiece (1000), the timepiece (1000) comprising at least one timepiece movement (100) according to claim 15.

17. Timepiece (1000), the timepiece (1000) comprising at least one barrel assembly (1) according to any one of claims 1 to 14 for storing energy, the barrel assembly (1) having an input formed by a ratchet (12) mounted for integral rotation with the core (4) or by a drum toothing (13) mounted for integral rotation with the drum (3), and an output formed respectively by a drum toothing (13) mounted for integral rotation with the drum (3) or by a ratchet (12) mounted for integral rotation with the core (4).