HK1192331B - Capsule for scientific instrument - Google Patents

Description

Capsule for scientific instrument

Technical Field

The present invention relates to a capsule comprising two shells fixed to each other, such that they are joined by a common closure surface and together define a closed space bounded by the shells on either side of said surface. At least one of the two shells is a flexible membrane that can be deformed by a physical quantity.

Background

Scientific instruments or portable objects comprising a housing containing a pressure sensor, such as a diving watch or altimeter, are known in the art. The sensor includes a membrane and a transmission device. The membrane can be mechanically deformed by an external pressure acting on the transfer device. The device therefore transmits, for example, a deformation movement (representative of the pressure/intensity) so as to amplify said movement, in order to display the value of the pressure detected by the sensor.

It is also known to use these bellows as an energy source for a timepiece. These capsules contain a liquid such as ethyl chloride. These liquids react to temperature changes and evaporate as the temperature rises, thus increasing the pressure inside the capsule. The bellows cooperates with a winding spring held by a housing connected to the chain by a pulley. The winding spring winds the barrel spring in a series of back and forth movements via a ratchet system (ratchet and idler).

As the temperature rises, the bellows tightens the winding spring causing the chain to slacken and release the pulley. When the temperature drops, the bellows contract, causing the winding spring to pull the chain and tighten the barrel.

Generally, these capsules are made by assembling two shells or membranes via their peripheries or edges such that a space exists between the two membranes. The membrane forming the capsule is made of a crystalline material such as, for example, an alloy comprising copper and beryllium (Cu-Be).

The characteristics of various materials are represented by their young's modulus E or elastic modulus (generally expressed in GPa) representing their resistance to deformation. In addition, the elastic extremum σ can be used_eThe characteristics of various materials are expressed (generally expressed in GPa), the elastic extrema representing the stress beyond which the material plastically deforms. Thus, the ratio σ of the elastic extreme value to the Young's modulus can be established for various materials_eThe materials with a given thickness are compared as the ratio represents the elastic deformation of the various materials. Thus, the higher the ratio, the greater the elastic deformation of the material. However, the crystalline materials used in the prior art, for example copper beryllium (Cu-Be) (Young's modulus E equal to 130GPa, typical extreme elasticity σ_e1GPa) has a low ratio σ of about 0.007_eAnd E is used. The elastic deformation of these crystal alloy capsules is therefore limited. In applications of altimeters or energy sources for tightening barrels, this implies a limited measuring range and a low tightening force, respectively.

Furthermore, because of the low elastic limit, when the capsule is deformed, at low stress levels the capsule approaches its plastic deformation limit, with the risk of not returning to its original shape. To prevent this type of deformation, it is necessary to limit the deformation of the bellows, i.e. to intentionally limit the amplitude of the bellows movement. It is thus clear that for altimeter applications, the transfer motion must be amplified. This produces noise which is harmful and inevitably detrimental to the height indicator and to the display of the measured values.

Furthermore, the space between the membranes is under vacuum or filled with a liquid. The capsule must be sealed against leakage. To achieve this, solder is typically used to secure the two membranes and seal the capsule against leakage.

This method of assembling and sealing the capsule limits the types of materials that can be used. Indeed, one skilled in the art may envision the use of mechanically better materials, such as metallic glasses or amorphous metals. However, the use of the above-described commonly used manufacturing methods for such materials is abandoned by those skilled in the art. The reasons for this choice are: since the person skilled in the art has the following prejudices: conventional processes cannot be used to manufacture the capsule without changing the characteristics of the capsule. In fact, they have the following prejudices: the use of welding/soldering to assemble and seal these capsules will change the properties of the amorphous material forming the capsule, as the welding process requires an increase in temperature. This increase in temperature may in turn cause the amorphous metal to crystallize if the temperature reaches a temperature between the crystallization temperature and the glass transition temperature of the amorphous metal.

This partial crystallization of the capsule will result in a change of its properties and thus in different properties. Those skilled in the art will therefore not be concerned with the use of amorphous metals for the manufacture of capsules.

Disclosure of Invention

The present invention relates to a capsule that overcomes the above-mentioned drawbacks of the prior art by proposing a more reliable capsule with a safety margin for the maximum stress applied, while also having a greater amplitude of possible deformation. Alternatively, the present invention provides a capsule that can provide the same magnitude of deformation with a smaller size.

The invention therefore relates to a capsule comprising two shells fixed to each other so that they are joined by a common closure surface, said two shells together defining, on both sides of said surface, a closed space delimited by said shells, said two shells being flexible membranes deformable under the action of a physical quantity, characterized in that at least one of said membranes is made of a metal alloy that is at least partially amorphous in order to optimize the dimensions of said capsule.

In a first advantageous embodiment, the ratio of the elastic extremum of said metal alloy of said membrane to the young's modulus is greater than 0.01.

In a second advantageous embodiment, said metal alloy of said thin film has a young's modulus of more than 50 GPa.

In a third advantageous embodiment, the two shells are flexible deformable membranes.

In a fourth advantageous embodiment, said two flexible deformable membranes are made of said metal alloy which is at least partially amorphous.

In another advantageous embodiment, the capsule is in one piece, the two shells forming the same part.

In another advantageous embodiment, the metal alloy is completely amorphous.

In another advantageous embodiment, the metal alloy comprises at least one metal element which is a noble metal element and is selected from the group of metals comprising: gold, platinum, palladium, rhenium, ruthenium, rhodium, silver, iridium or osmium.

In another advantageous embodiment, the metal alloy does not comprise any allergen.

In another advantageous embodiment, each membrane is substantially disc-shaped.

In another advantageous embodiment, each membrane has a non-rectilinear cross section to increase its deformation surface.

In another advantageous embodiment, the cross-section of the membrane comprises at least one sinusoidal portion.

A first advantage of the bellows of the present invention is that it has more favorable elastic properties. In fact, in the case of amorphous materials, by increasing the elastic limit σ_eTo increase sigma_eThe ratio of E to E. The stress limit is thus increased-beyond which the material will not return to its original shape. Sigma_eAn increase in the/E ratio therefore causes a large change in shape. This optimizes the size of the capsule-whether in terms of the desire to increase the measurement range or increase the deformation of the capsule or to decrease the size of the capsule for an equivalent measurement or deformation range.

Another advantage of these amorphous materials is that they have new forming possibilities for developing complex-shaped parts with higher precision. In fact, amorphous metals have the following special characteristics: in a given temperature range [ Tg-Tx ] (where Tx is the crystallization temperature and Tg is the glass transition temperature) specific to each alloy, amorphous metals can be made soft while remaining amorphous. It is therefore possible to shape/form these metals with a lower level of stress and a lower temperature. This means that fine geometries can be replicated very accurately, since the viscosity of the alloy will be greatly reduced, and therefore the alloy will have all the detail patterns of the die.

This accuracy can also be achieved by injecting liquid metal into the mold. The metal is then rapidly cooled to prevent crystallization and thus becomes amorphous. This method is advantageous because amorphous metals do not have a crystalline structure when solidified, and amorphous metals undergo solidification shrinkage only very slightly. Thus, in the case of crystalline materials, the curing shrinkage may reach 5% to 6%, which means that the capsule will reduce its size by 5% to 6% upon curing. However, in the case of amorphous metals, the shrinkage is about 0.5%.

Furthermore, the invention also relates to a scientific instrument, characterized in that it comprises a pressure sensor using a capsule according to the invention.

In another advantageous embodiment, the scientific meter further comprises means for converting a value representing the pressure into a depth value, thereby allowing the scientific meter to perform a depth measurement function.

In another advantageous embodiment, the scientific meter further comprises means for converting the value representing the pressure into a height value, thereby allowing the scientific meter to perform a height measurement function.

In a further advantageous embodiment of the scientific instrument, the space between the two housings is at 10-³To 10-⁷In a vacuum of mbar.

In another advantageous embodiment, the meter is a portable timepiece.

Furthermore, the invention relates to a timepiece characterized in that it comprises a capsule according to the invention for tightening a barrel that powers said timepiece.

Advantageous embodiments of the timepiece form further subject matter of the invention.

Drawings

The objects, advantages and features of the capsule according to the invention will become more apparent in the following detailed description of at least one embodiment thereof, given by way of non-limiting example only and represented by the accompanying drawings, in which:

fig. 1 shows a schematic cross-sectional view of a capsule according to the invention.

Figure 2 shows a schematic cross-section of a variant of the capsule according to the invention.

Figure 3 shows a schematic cross-section of a variant of the capsule according to the invention.

Fig. 4 shows deformation curves for crystalline and amorphous materials.

Figure 5 shows a schematic cross-section of a one-piece variant of the capsule according to the invention.

Fig. 6 is a longitudinal section of a watch including a pressure sensor using a capsule according to the invention.

Fig. 7 and 8 show longitudinal sectional views of a bellows and a timepiece using the bellows for tightening a barrel according to the present invention.

Detailed Description

Fig. 1 and 2 show a sectional view of a capsule 1 according to the invention. The capsule 1 is formed by two shells 2. The two shells 2 are joined by a common closure surface 4 and together define, on each side of said common surface, a closed space 3 delimited by said shells 2.

Advantageously, the two shells 2 are fixed to each other so that the space 3 between the two shells 2 is completely isolated from the outside space.

According to the mentioned application, at least one of the two housings 2 is provided as a deformable membrane. The membrane 2 is arranged to be deformable under the influence of physical quantities such as temperature and pressure, and the deformation is related to the physical quantities. Preferably, the two housings 2 are provided in the form of deformable membranes 2.

Advantageously according to the invention, at least one of the membranes 2 of the capsule 1 comprises an amorphous material, i.e. a partially amorphous or a completely amorphous material. The partially or fully amorphous material is obtained by the following operations: the elements forming the material are melted and mixed and then rapidly cooled to at least partially or completely prevent crystallization of the material. In particular, metallic glasses, i.e. amorphous metal alloys, are used. Preferably, the capsule 1 comprises two membranes 2 made of amorphous metal or alloy. This variation will be used in the following description. The capsule 1 (at least one of the membranes 2 of the capsule 1 comprising an amorphous or partially amorphous material) is therefore referred to as a "capsule made of an amorphous material".

In fact, the advantages of these amorphous metal alloys can be reflected by the fact that: during fabrication, the atoms forming the amorphous material do not place themselves into a particular structure as do the crystalline materials. Therefore, even if the Young's moduli E of the crystalline material and the amorphous material are close, their elastic extreme values σ are close_eAnd are also different. The amorphous material therefore differs in its elastic limit σ_eaAs shown in fig. 4, is higher than the elastic limit value of the crystalline metal by a ratio substantially equal to 2. The figure shows the curves of the stress σ of an amorphous material (dashed line) and a crystalline material according to the deformation ε. This means that the amorphous material is able to reach the elastic limit σ_ePreviously subjected to greater deformation.

Firstly, the capsule 1 with at least one envelope 2 made of amorphous material improves the mechanical reliability, which has been found to be comparable to that of the capsule 1 made of crystalline material. In fact, the elastic extreme σ_eaHigher, which means that the plastic domain is larger, the risk of plastic deformation of the capsule 1 under the influence of the applied stress is reduced.

Secondly, it should be noted that the capsule 1 with at least one casing 2 made of amorphous material optimizes the dimensions of the casing to be able to cover the same stroke for the same stress applied in the centre (i.e. at a distance from the abutment surface of the casing 2). It is assumed that the dimensions of the capsule 1 change its deformation. It should therefore be noted that if the diameter increases, the theoretical stroke of the capsule 1 increases. Furthermore, if the thickness increases, the theoretical stroke of the capsule 1 decreases. Advantageously, if the elastic extrema increase, the stress that can be applied to the capsule 1 without any elastic deformation increases. The same amplitude of movement can be maintained by reducing the diameter and thickness of the bellows. The capsule 1 thus becomes more compact.

For the material itself, σ can be considered first_eThe higher the ratio/EThe more effective the capsule 1. Advantageously, σ_eMaterials with a higher E ratio than 0.01 are the most suitable materials for the manufacture of the capsule 1. It should also be noted that other than σ_eIn addition to the/E ratio, the value of E should also be chosen to be higher than a certain extreme value, preferably set at 50GPa, so that the capsule can be contained within an acceptable volume.

Next, other characteristics should also be considered. Therefore, it can be considered that: corrosion resistance and non-magnetic properties are particularly advantageous for a diving watch. "non-magnetic" means a soft magnetic material, preferably having a relative permeability of approximately 50 to 200, and in particular having a high saturation magnetic field value of more than 500A/m. The following materials may be cited as amorphous materials that may be used: zr₄₁Ti₁₄Cu₁₂Ni₁₀Be₂₃(Young's modulus E of the material is 105GPa, and an elasticity extreme value sigma_e1.9GPa) of_eThe ratio of/E is 0.018, and Pt_57.5Cu_14.7Ni_5.3P_22.3(Young's modulus E of the material is 98GPa, and an elasticity extreme value sigma_e1.4GPa) of_ethe/E ratio is 0.014.

Of course, there are other features that may be advantageous, such as the allergenic aspects of the alloy. In fact, it should be noted that whether the material is a crystalline material or an amorphous material, they often use alloys that include allergens. These types of alloys include, for example, cobalt or nickel. Thus, variants of the capsule according to the invention can be made of alloys that do not contain these allergens. It can also be provided that: these allergens are present but do not cause allergic reactions. For this purpose, it can be provided that the capsule 1 containing these allergens does not release them when the capsule 1 is corroded away.

According to another variant of the invention, the capsule 1 can be made of precious/rare material. In fact, in the crystalline state, alloys made of precious materials such as gold or platinum are very soft and cannot make a flexible and robust capsule 1. However, as long as they take the form of metallic glass (i.e. amorphous state), these noble metal alloys are then provided with features that make it possible to use them for the manufacture of capsules 1 and at the same time provide a rare and beautiful appearance. Preferably, platinum 850(Pt850) and gold 750(Au 750) are the noble metal alloys used to fabricate the capsule. Of course, other noble metals such as palladium, rhenium, ruthenium, rhodium, silver, iridium or osmium may also be used. The use of these amorphous noble metal alloys for the capsule is contrary to the preconceived idea regarding the low mechanical properties of noble metals.

A great advantage of amorphous metals or amorphous metal alloys is their great plasticity. In fact, amorphous metals have the following unique characteristics: in a given temperature range specific to each alloy [ Tx-Tg ]]Amorphous metals become soft while remaining amorphous (e.g., Zr)_41.24Ti_13.75Cu_12.5Ni₁₀Be_22.5Alloy Tg 350 ℃, and Tx 460 ℃). These metals can therefore be shaped/formed/reshaped at relatively low stress (1MPa) and low temperature (i.e. below 600 ℃).

The method of shaping includes hot working an amorphous preform. The preform is obtained by melting the metallic elements forming the amorphous alloy in a furnace. The melting is performed in a controlled atmosphere environment to obtain the lowest possible oxygen contamination of the alloy.

For example, to manufacture one of the membranes 2 of the capsule 1, the molten element is cast in the form of a semifinished product (for example, a disk, with dimensions similar to those of the membrane 2) and then rapidly cooled to maintain the amorphous state. Once the preform is obtained, hot working is used to obtain the finished part. The thermal processing is accomplished by pressing at a temperature in the range between Tg and Tx for a predetermined period of time to maintain a fully or partially amorphous structure. For this hot working method, pressing is followed by cooling. The pressing and cooling must be fast enough to prevent any crystallization of the material forming the film 2. In fact, for a given material, at a given temperature between its glass transition temperature Tg and its crystallization temperature Tx, there is a maximum duration beyond which the material crystallizes. When in useThis duration decreases as the temperature approaches its crystallization temperature Tx and increases as the temperature approaches its glass transition temperature Tg. Thus, if the time spent at the temperature comprised between Tg and Tx exceeds a specific value for each temperature/alloy combination, the amorphous material will crystallize. Typically, for Zr_41.2Ti_13.8Cu_12.5Ni₁₀Be_22.5The combination of alloy and 440 c temperature should not exceed approximately 120 seconds of pressing time. Thus, the initial state of the preform, which is at least partially amorphous, can be maintained.

This is done to maintain the typical elastic properties of amorphous metals. The final shaping steps of the capsule 1 are therefore:

i. the mold having the negative shape of the film 2 is heated to a selected temperature.

inserting the amorphous metal disk between the heated molds.

Applying a closing force to the mold to replicate the geometry of the mold on the amorphous metal disk.

Wait for the selected maximum time.

v. opening the mold.

Rapidly cooling the film below Tg.

Finally, the film 2 is removed from the mold.

The shaping method allows to reproduce very accurately fine geometries, since the viscosity of the alloy is greatly reduced, and therefore the alloy has all the details of the shape of the die. For example, for platinum-based materials, up to 10 ℃ at temperatures of approximately 300 ℃³Viscosity of Pa.S, stress of 1MPa, not at Tg, 10¹²At a viscosity of pa.s, shaping occurs. The advantage of this method is that there is no cure shrinkage, which will enable the part to perfectly replicate the contours and detailed shape of the mold.

Of course, other types of shaping methods, such as casting or injection molding, may also be used. The method comprises the following steps: an alloy obtained by melting a metallic element in a furnace is molded, wherein the alloy can be in the form of any part such as a strip, which may be in a crystalline state or an amorphous state. The arbitrarily shaped alloy part is then remelted to enable it to be poured or pressure injected into a mold having the shape of the finished part. Once the mold has been filled, it is rapidly cooled to a temperature below Tg to prevent the alloy from crystallizing, thus obtaining an amorphous or semi-amorphous metal film. This method is advantageous because amorphous metals do not have a crystalline structure when they solidify, and amorphous metals undergo solidification shrinkage only very slightly. Thus, in the case of crystalline materials, the curing shrinkage can reach 5% to 6%, which means that the capsule 1 will reduce its size by 5% to 6% when it is cured. However, in the case of amorphous metals, the shrinkage is about 0.5%. Furthermore, pouring or injection is a well established method and is therefore simple and cheap.

Once the two membranes 2 have been formed, they are assembled to each other at their common closure surface or edge 4 to form a capsule. The joining of the two films 2 can be done in various ways, such as welding, soldering or gluing.

Another approach is to use the properties of amorphous metals. For this purpose, two films 2 are placed on top of each other. The outer periphery of the film is thus heated to a temperature between Tg and Tx. Then, the outer periphery is pressed between the jigs. These clamps comprise struts configured in comb form, so that when the periphery is pressed by the clamps, the struts of the clamps create a mechanical interaction between the two films 2 and fix them to each other.

Preferably, this fixing operation is performed so that the capsule 1 is sealed and the space 3 between the two membranes 2 is completely isolated from the outside.

After curing, a step of vacuum cavitation or filling is performed. The vacuum present in the capsule 1 is substantially 10^-3To 10^{- 7}mbar, it is believed that the higher the vacuum, the better the performance. This vacuuming or filling operation is generally done via an orifice 5 made on one of the films 2 as shown in figure 3. This orifice 5 is then blocked by applying a metal stopper. The orifice 5 is preferably positioned in the centre of one of the membranes 2, since this is where little stress is experienced, unlike the orifices provided at the junction between two membranes 2, where they are joined to each other.

In other variants of the method used, the plasticity of the amorphous metal advantageously means that the capsule 1 can be formed as a single piece as shown in fig. 5. In fact, using a thermoforming or casting method, it is possible to manufacture a mold or die that forms the precise pattern for the capsule 1. These methods are used to fill a mold or die with the amorphous metal described above. The complementary step is to dissolve/separate the mold or die.

In fact, in order to manufacture the capsule 1, the mold or die must comprise a core that forms the spaces between the films, which will be evacuated or filled with a liquid. When the capsule 1 is manufactured, amorphous metal is deposited around the core, thereby confining the core within the amorphous metal. The capsule 1 is then removed from the mold by dissolving the mold or form in a chemical bath. The product used is selected according to the material from which the mold or die is formed. The capsule 1 thus formed contains only 1 orifice 5, which orifice 5 must be blocked to seal the capsule.

The next step consists in filling the capsule 1 with a liquid or in creating a vacuum in said capsule 1, depending on the application, and then in blocking the orifice 5 to ensure that the capsule 1 is sealed. This liquid filling or evacuation is performed via the orifice 5 formed during hot working or casting.

This variant has several advantages. First of all, this variant provides a capsule 1 that is easier to manufacture, since there is no operation of joining the two membranes 2, and therefore one step less. The bonding operation is complicated because it is necessary to provide a durable bond and a proper seal without crystallizing the amorphous metal. By manufacturing the one-piece capsule 1, there is no membrane 2 to be joined and therefore no sealing problems associated with the joining. The single-piece capsule 1 thus fundamentally prevents the complex problems to be solved from arising. Sealing the capsule 1 is simpler, since only the opening 5 for filling the capsule 1 with liquid or evacuating the capsule 1 needs to be blocked, instead of the entire periphery of the capsule 1 needing to be sealed.

Moreover, this variant makes better use of the surface of the capsule 1. In fact, when manufacturing the capsule 1 by joining two membranes 2, the membranes 2 must be designed such that the common closure surface or joining area 4 does not adversely affect the performance of the capsule 1. For this purpose, the membranes 2 are designed such that their outer periphery is the area specifically for the joint and not the active area during operation of the capsule 1. This particular engagement area is therefore not used for the operation of the bellows. With the method of this variant, there is no joint and it is therefore no longer necessary to have a useless region for this joint. The capsule 1 is therefore more compact and simpler to design.

An alternative solution to this variant consists in using a blow-moulding process. For this purpose, the preform 4 is manufactured from an amorphous material. The preform is made by casting the molten elements forming the desired alloy in the form of a semi-finished product, such as a sphere, a tubular body or a tubular body with a base, and then rapidly cooling the preform to maintain the amorphous state.

This preform is then placed in a mold having the same pattern as the desired bellows to be made.

The preform is then heated to a temperature comprised between Tg and Tx, so that the amorphous metal becomes viscous and susceptible to ductile deformation.

Next, a blowing nozzle is inserted into the preform, thus enabling the blowing step to be started. The blowing step consists in blowing pressurized air or gas into the preform. The preform is stretched under this pressure because the metal forming the preform is viscous. The stretching of the amorphous metal causes the metal to adhere to the walls of the pattern cavities of the mold. The amorphous metal is then rapidly cooled so that it does not crystallize.

The final step consists in removing the cooled capsule from the mould by opening the two-piece mould.

The advantage of this alternative solution is that the mould is relatively simple, since it is made of two parts that are fitted together. Furthermore, the method is less complex, since there is no core for forming the closed space between the films 2, as compared to the previously described one-piece component method, and therefore a conventional reusable mold can be used.

Furthermore, the plastic properties of the amorphous metal mean that the membrane 2 or the capsule 1 can be produced in the desired geometry. For example, the properties of the membrane 2 or the capsule 1 can be varied by shaping its cross section and its thickness or diameter. By way of example, a film 2 having a sinusoidal cross-section 6 as shown in fig. 2, 3 and 5 can be obtained. This type of shape can increase the surface area of the membrane as well as its stiffness. The membrane is thus more difficult to deform. This cross-sectional arrangement advantageously means that the elastic deformation of the material can be linearized as a function of the pressure. This linearization thus contributes to simplifying the means of converting the deformation of the membrane 11 into a pressure value.

The capsule 1 can also be used in a scientific instrument such as a diving watch 10 as shown in fig. 6, which instrument comprises a case 11, which case 11 houses an intermediate part 12, on which intermediate part 12 a case bezel 13 is fixed, which carries a crystal 14 of the watch 10. Below the crystal surface 14, a display device 15 is provided which is also fixed to the intermediate member 12. In this type of application, the interior space of the capsule 1 is under vacuum.

Watch 10 is closed by a back cover 17 which is fixed in a sealed manner to an intermediate part 18, wherein intermediate part 18 is in turn fixed in a sealed manner to intermediate part 12, thus forming a case. The watch also includes a pressure sensor 16 preferably located inside the housing 211.

The pressure sensor 16 comprises a transmission device 20 and a capsule 1. The capsule is located inside the case 11 of the watch 10 and is fixed to the support 22. This ensures good deformation of the bellows. In this example, the support body 22 is fixed to the intermediate member 18. The support body 22 and the intermediate part 18 are arranged such that the outer surface of the capsule 1 is in contact with and can be deformed by external pressure. In order to allow the capsule 1 to be in contact with the external environment, the rear cover 17 of the casing 21 has a plurality of apertures or holes 23 pierced, these apertures or holes 23 allowing the membrane 2 of the capsule 1 to deform if the external pressure and the pressure inside the capsule 1 are different.

Furthermore, it can be provided that the rear cover 17 of the housing 21 is fitted with a removable cover 21, which cover 21 can be fitted in a snap-on manner to block the orifice or hole 23 when no pressure measurement is required. This protects the pressure sensor 16.

The delivery device 10 is used in conjunction with the bellows for operation of the pressure sensor 16. Thus, the bellows will deform more or less under the influence of the pressure difference between the space 3 and the outside environment. In fact, if the external pressure is greater than the pressure inside the capsule 1, the latter then deforms and reduces the volume of the space 3 of the capsule 1. Conversely, in highland, where the external pressure is lower than the pressure inside the capsule 1, the capsule will deform so that the volume of the space 3 of the capsule 1 increases.

This deformation of the capsule acts on the transmission device 20, which transmission device 20 detects the capsule position relative to the original position of the capsule 1. The home position is preferably a position in which the pressure on both sides of the bellows is equal. Once the detection has been performed, the transmission device 20 will transmit information of the deformation of the capsule, for example by mechanical movement.

The movement representative of the pressure transmitted by the device 20 can be amplified and then utilized by the display device 15. The display device uses means for converting the motion representing the deformation and thus the pressure into a depth value or a height value. The device 15 will then display the depth measured by said pressure sensor 16. Of course, the pressure detection may be performed by any other means, such as a piezoelectric transducing device. Furthermore, other functions utilizing pressure, such as an altitude measurement function or a meteorological monitoring function, are also contemplated.

The elements of the sensor 16 are therefore calibrated according to predetermined specifications defining the desired measuring range of the bellows stroke. The desired measurement range represents the maximum or minimum pressure value that needs to be detected and displayed. For example 100 meters deep. The stroke of the capsule obtained by adding the deformations of the respective housings 2 with respect to their rest position defines the maximum deformation that can be reached by the capsule. Thus, the characteristics of the capsule are defined from these two values. The capsule is characterized by its dimensions (e.g., the capsule has a diameter of 40mm and a thickness of 3 mm) and the material from which it is formed.

Another application of the capsule 1 according to the invention is its use as an element for a barrel 107 in a wind-up timepiece 100, as shown in fig. 7 and 8. For this purpose, the capsules 1 are filled with a liquid, such as ethyl chloride. The liquid reacts to temperature changes, evaporating as the temperature rises and thus increasing the pressure inside the capsule. The bellows increases in volume and thus cooperates with the winding spring 101. The winding spring is held by a housing 103 connected to the chain 102 by a pulley 104. When there is a temperature or pressure change, the bellows 1 causes the chain 102 to move and thus rotate the pulley 104. The pulley cooperates with a ratchet system of ratchet 105 and idler 106 to wind a mainspring 107.

The advantage of the capsule according to the invention compared to capsules made of crystalline material is that the capsule 1 made of amorphous material has a greater stroke. This therefore means that barrel 107 will be tightened to a greater extent, since chain 102 will have a greater amplitude of movement. The rotation of the pulley 104 is therefore greater, thus tightening the barrel 107 more quickly and efficiently. If the stroke of the amorphous metal capsule 1 is larger than the stroke of the crystalline metal capsule 1, the same stroke can be obtained with a more compact capsule 1 and thus a more compact timepiece.

Moreover, the bellows of the application for tightening the barrel advantageously comprises a bellows 6. The bellows 6, formed by several stages, is arranged at the periphery of the capsule 1 and serves to contain the liquid of the capsule 1 when said capsule is deflated. The constriction at the centre of the bellows thus drives the liquid which will be contained in the stages of the bellows 6. The bellows is subjected to stress from the liquid and deforms under the action of the stress. With amorphous metal, the bellows 6 can be reduced in size. This is possible because the amorphous metal can withstand greater stresses before undergoing plastic deformation and therefore the stages of the bellows 6 can contain more liquid.

It will be apparent to those skilled in the art that many modifications and/or improvements and/or combinations of the various embodiments of the invention set forth above are possible without departing from the scope of the invention as defined by the appended claims. For example, the bellows or membrane may have different shapes. At the same time, it is also obvious that the capsule according to the invention can be used in triggering devices, time delay devices and physical quantity changing devices, such as in triggering systems for various applications (blasting, drilling, mining, etc.).

Claims (26)

1. A capsule (1) comprising two shells (2) fixed to each other so as to be joined by a common closure surface (4), which together define, on both sides of the common closure surface, a closed space (3) delimited by the shells, the two shells being flexible membranes (2) deformable under the effect of a physical quantity, characterized in that only one of the membranes is made of a metal alloy that is at least partially amorphous in order to optimize the dimensions of the capsule, and in that the two fixed shells are supported only at the periphery of the common closure surface.

2. The bellows of claim 1 wherein the metal alloy has a ratio of elastic extremum to young's modulus greater than 0.01.

3. The bellows of claim 1 wherein the metal alloy has a young's modulus greater than 50 GPa.

4. The capsule of claim 1, wherein the metal alloy is fully amorphous.

5. The capsule according to claim 1, characterized in that said metal alloy comprises at least one noble metal element and is selected from the list of metals: gold, platinum, palladium, rhenium, ruthenium, rhodium, silver, iridium or osmium.

6. The capsule according to claim 1, characterized in that said metal alloy is free of any allergen.

7. Capsule (1) according to claim 1, characterized in that each membrane (2) is substantially disc-shaped.

8. A capsule according to claim 1, characterized in that each membrane (2) has a non-rectilinear section to increase the deformed surface of each membrane.

9. The bellows of claim 8, wherein the cross-section of the membrane comprises at least one sinusoidal portion.

10. Scientific meter (10) comprising a pressure sensor (16) comprising a capsule (1) cooperating with a transmission device (20) for providing a value representing pressure from a deformation of the capsule, characterized in that the capsule is a capsule according to any one of claims 1 to 9.

11. The scientific meter of claim 10 further comprising means for converting said pressure-representative value to a depth value, thereby allowing said scientific meter to perform a depth measurement function.

12. The scientific meter of claim 10 further comprising means for converting the value representative of pressure to a height value, thereby allowing the scientific meter to perform a height measurement function.

13. Scientific instrument according to claim 10, characterized in that the space (3) between the two housings (2) is at 10^-3To 10^-7In a vacuum of mbar.

14. Scientific instrument according to claim 10, characterized in that said instrument (10) is a portable timepiece.

15. Timepiece (100) comprising a movement powered by a mainspring (107) wound by a winding system, characterized in that said winding system is actuated by a capsule (1) according to any one of claims 1 to 9, which contracts or expands as a function of temperature or pressure when at least one physical quantity varies.

16. The timepiece according to claim 15, characterised in that the space (3) between the two shells (2) is filled with a liquid that reacts to a change in temperature.

17. Capsule (1) comprising two shells (2) fixed to each other so as to be joined by a common closure surface (4), which together define, on both sides of the common closure surface, a closed space (3) delimited by the shells, the two shells being flexible membranes (2) deformable under the effect of a physical quantity, characterized in that the two deformable flexible membranes are made of a metal alloy that is at least partially amorphous in order to optimize the dimensions of the capsule, and in that the two fixed shells are supported only at the periphery of the common closure surface.

18. The bellows of claim 17 wherein the metal alloy has a ratio of elastic extremum to young's modulus greater than 0.01.

19. The bellows of claim 17 wherein the metal alloy has a young's modulus greater than 50 GPa.

20. The capsule according to claim 17, characterized in that said capsule (1) is of a single piece, said two shells (2) forming the same single part.

21. The capsule of claim 17, wherein said metal alloy is fully amorphous.

22. The capsule according to claim 17, characterized in that said metal alloy comprises at least one noble metal element and is selected from the list of metals: gold, platinum, palladium, rhenium, ruthenium, rhodium, silver, iridium or osmium.

23. The capsule according to claim 17, wherein the metal alloy is free of any allergen.

24. Capsule (1) according to claim 17, characterized in that each membrane (2) is substantially disc-shaped.

25. A capsule according to claim 17, characterized in that each membrane (2) has a non-rectilinear section to increase the deformed surface of each membrane.

26. The bellows of claim 25 wherein the cross-section of the membrane includes at least one sinusoidal portion.