CH710488A2 - Cladding element for a timepiece comprising a pressure sensor. - Google Patents

Abstract

The present invention relates to a cladding element of a timepiece comprising a reinforcement made of a first material, said cladding element further comprising at least one pressure sensor (120), characterized in that said sensor pressure is formed of at least one pellet (122), said pellet being composed of a binder and a piezochromic pigment, said piezochromic pigment being chosen to react to a specific pressure so that said pigment passes from a first color to a second color when said specific pressure is reached.

Description

[0001] The present invention relates to a covering element for a timepiece comprising a frame made of a first material, said covering element further comprising at least one pressure sensor.

TECHNOLOGICAL BACKGROUND

[0002] There are known portable objects such as watches equipped with pressure sensors allowing altitude detection. These pressure sensors can take the form of a piezoelectric sensor used to transform a stress, the pressure of air or water, into an electrical signal that will be analyzed by a microcontroller.

[0003] A drawback of these piezoelectric sensors is that they have a lag time for the display of the pressure and therefore of the altitude. It also requires a microelectronic system and therefore a source of energy to operate.

[0004] Another known possibility is a diver's watch which allows water to penetrate into a groove or leads to the very interior of the sapphire crystal, which makes it possible to measure the depth reached. This process is based on the so-called Boyle-Mariotte physical law. If the pressure increases, the volume of gas decreases. The more water enters the gauge, the more the air inside is compressed. The point of contact between water and air indicates the depth on a scale around the edge of the dial.

[0005] A drawback of this solution is that it presents the risk of water drops getting stuck in the duct creating an air bubble distorting the mechanism and therefore making the reading of the information unreliable.

Another possibility is to use a closed capillary filled with a fluid in a reservoir connected to the capillary. This closed circuit is inserted between two plates so that depending on the pressure, the reservoir compresses causing the fluid to move through the capillary, which makes it possible to determine the depth or altitude.

[0007] However, this complex solution to implement requires a fluid with physical properties limiting the decorative possibilities.

SUMMARY OF THE INVENTION

[0008] The invention relates to a covering element which overcomes the aforementioned drawbacks of the prior art by providing a portable object capable of providing an indication of altitude in a readable and reliable manner.

[0009] To this end, the object of the invention is to provide a covering element for a timepiece comprising a frame made of a first material, said covering element further comprising at least one sensor of altitude, characterized in that said altitude sensor is formed from at least one pellet, said pellet being composed or coated with a binder and a piezochromic pigment, said piezochromic pigment being selected to react to a specific pressure felt at the surface of the pellet, so that said pigment changes from a first color to a second color when said specific pressure is reached.

[0010] In a first advantageous embodiment, said altitude sensor is formed of a plurality of pellets, each pellet reacting to a specific pressure which is specific to it.

[0011] In a second advantageous embodiment, said pellets all have the same first color.

[0012] In a third advantageous embodiment, said pellets all have the same second color.

[0013] In a fourth advantageous embodiment, said pellets are designed so that their second color allows a gradient when they have all changed from the first color to the second color.

[0014] In a fifth advantageous embodiment, said altitude sensor allows the measurement of a positive altitude with respect to sea level.

[0015] In a sixth advantageous embodiment, said altitude sensor allows the measurement of a negative altitude relative to sea level.

[0016] In another advantageous embodiment, said altitude sensor allows the measurement of a depth underwater.

[0017] In another advantageous embodiment, the pellet is in the form of an ink or paint or lacquer deposited on the frame, said frame being hollow.

[0018] In another advantageous embodiment, the pellet is in the form of an insert formed of a hollow body tight to water and air, said hollow body being coated with said piezochromic pigment.

In another advantageous embodiment, the pellet is in the form of an insert formed of a hollow body impermeable to water and air, said piezochromic pigment being dispersed in the material forming said body .

[0020] In another advantageous embodiment, the frame comprises at least one recess in which the pellet is arranged.

[0021] In another advantageous embodiment, the frame is a bezel.

[0022] In another advantageous embodiment, the frame is a mirror.

[0023] In another advantageous embodiment, the frame is a watch case middle part.

[0024] In another advantageous embodiment, the frame is a bracelet.

[0025] In another advantageous embodiment, the bracelet comprises two bracelet strands made of plastic materials, said altitude sensor being arranged on at least one of the two strands.

[0026] In another advantageous embodiment, the bracelet comprises a plurality of links articulated together, said altitude sensor being arranged on at least one link.

[0027] In another advantageous embodiment, said bracelet is closed by a folding clasp, said altitude sensor being arranged on said clasp.

[0028] In another advantageous embodiment, the frame is a crown.

[0029] In another advantageous embodiment, said piezochromic pigment is coupled with a luminescent pigment to emit a more intense color.

BRIEF DESCRIPTION OF THE FIGURES

[0030] The advantages of such a covering element will become clear on reading the following description and on examining the drawing which illustrates it by way of example and in which: FIGS. 1 and 2 schematically represent a timepiece according to the present invention; figs. 3 and 4 schematically show a bezel forming the covering element according to the present invention, FIGS. 5 and 6 schematically show a mirror forming the covering element according to the present invention, FIG. 7 schematically shows a middle part forming the covering element according to the present invention; FIG. 8 schematically shows a bracelet strand forming the covering element according to the present invention; FIG. 9 schematically shows the links of the bracelet strand forming the covering element according to the present invention; FIGS. 10 to 12 schematically represent a bracelet clasp forming the covering element according to the present invention

DETAILED DESCRIPTION

[0031] The present invention relates to a covering element 1 of a timepiece or watch 100.

[0032] The timepiece 100, visible in FIGS. 1 and 2, is for example a wristwatch and comprises a case 102. This case is formed by a middle part 104 closed by a back 106 and a crystal 108. The timepiece may include a dial 109 and display means 109a. The timepiece also includes a bracelet 110. The latter is attached to the middle via two pairs of lugs 112. The bracelet can be made up of two strands, each strand being fixed to a pair of lugs and connected to the other strand. via a clasp.

[0033] The covering element 1 comprises a frame made of a first material. This first material can for example be a metallic, ceramic, composite or plastic material.

[0034] On this frame, at least one altitude sensor 120 is arranged. This altitude sensor 120 is used to allow the user to see what level he is in relative to a reference. Indeed, it is conceivable that the altitude sensor can allow the visualization of a positive altitude, that is to say positive in relation to the sea level but also of a negative altitude, that is to say below sea level.

Advantageously according to the invention, the altitude sensor comprises at least one piezochromic pellet 122. This piezochromic pellet is arranged on a hollow support tight to water and to the air, the cavity of which is at a known pressure PRef or is composed of a hollow body impermeable to water and air, the cavity of which is at a known pressure PRef. The pellet is also composed of a piezochromic pigment dispersed in a matrix. This matrix is a binder serving as a support for the pigment. This configuration makes it possible to have the piezochromic pigment seeing a pressure difference between the known pressure PRef and the external pressure felt.

Such a piezochromic pigment has a first color at ambient pressure and changes color to present a second color when the pressure reaches a value specific to said pigment. However, since depth and altitude are related to pressure, an indication of an altitude above or below sea level is possible. Thus, the pressure increases with depth and decreases with altitude.

[0037] This characteristic makes it possible to visually indicate the crossing of a pressure threshold.

[0038] In a preferred embodiment, the altitude sensor allows the visualization of an altitude scale. For this, the altitude sensor comprises a plurality of piezochromic pellets. Each piezochromic pellet includes a pigment reacting to a specific pressure. Therefore, each pellet changes color when a specific pressure is reached. To have an altitude scale, the specific pressures of the pellets will be made to increase or decrease. Thus, as the user wearing the portable object gains altitude, the patches change color over time, allowing visual indication. These pellets 122 can be glued to each other or spaced apart.

[0039] In a preferred variant, the various pellets making up the altitude scale all have a first color, that is to say an identical color at rest. By this we understand that at an altitude at sea level, all the pellets have the same color.

[0040] In another preferred variant, the various pellets making up the altitude scale have a whole second color, that is to say a color, when their specific threshold is reached, identical. It is understood by this that at the maximum measurable altitude, all the pellets will have the same color.

[0041] In another preferred variant, the different pellets making up the altitude scale all have an identical first color but are made so that they do not all have an identical second color in order to allow a gradation. Specifically, the pellets are designed so that, when forming an elevation scale, the pellets that change color first have a second, lighter color than the pellets that change color last. For example, the first pellets turn yellow and the last ones turn red. This allows a double indication: not only does the user know that the depth or altitude is increasing because the number of patches changing color increases, but he also knows that he is approaching a maximum altitude or depth because the color varies and becomes darker and darker.

[0042] It will therefore be understood here that the piezochromic pigment is of the reversible type. This means that when the pigment reaches or exceeds a specific pressure threshold, it changes color from a first color to a second color. But it also means that when the pressure goes back below the specific threshold, the pigment goes from the second color to the first color.

In an embodiment of said piezochromic pigment, the latter is used as a dispersion in a binder of between 0.01 and 5% by weight. The pigment includes without limitation a: - Triaryl imidazole dimers of Bis-2,4,5- triaryl imidazoles having one or more substituent groups selected from aryl groups such as phenyl, p-tolyel, p-chlorophenyl or p-anisyl

[0044] Preferred components are: 2, 2 ́, 4, 4 ́ 5, 5 ́ -hexaphenyl bisimidazole; 2, 2 ́, 4, 4 ́ 5, 5 ́ -hexa-p-tolyl bisimidazole; 2, 2 ́, 4, 4 ́ 5, 5 ́ -hexa-p-chlorophenyl bisimidazole; 2,2′ -di-p-chlorophenyl-4,4′, 5, 5 ́ tetraphenyl bisimidazole; the 2, 2 ́ -di-p-Anisyle-4, 4 ́,! 5 ́ -tetraphenyl bisimidazole; and 2, 2 ́ -di-p-tolyl-4, 4 ́ ,. 5 ́ -tetraphenyl bisimidazole. - Bistetraaryl pyrrole Bistetra phenyl pyrrole

- Bianthrones: A 10, 10 ́ -bianthrone; 2, 4, 2 ́, 4 ́ -tetramethyl bianthrone Xanthylidene anthrone.

- Dixanthylene. - Helianthrone. - Mesonaphthobianthrone.

The matrix used for the dispersion of the pigment can be of different kinds.

A first category of matrix comprises inks, lacquers and paints. This matrix consists of a polymeric binder mixed with at least one solvent, a plasticizer and a dispersant. Such a matrix can be a polyurethane, acrylic, polysilane and derivatives, silicone, epoxy, polyamide, cellulosic system or any other polymeric system making it possible to combine aesthetics and resistance specific to watch components.

[0047] A second category of matrix comprises thermoplastic granules. This matrix consists of a resin mixed with at least one dispersant and one plasticizer.

A third category of matrix comprises the rubber mixture. This matrix consists of an elastomer mixed with at least fillers, a dispersant and a vulcanization system.

A fourth category of matrix comprises thermosetting mixtures. These mixtures consist of a liquid resin mixed with at least one dispersant.

The second, third and fourth categories then make it possible to produce piezochromic pellets in the form of an insert by molding, pellets which can be assembled to components subsequently (the techniques of overmolding, gluing, screwing can be used). These categories also allow the molding of plastic components incorporating the piezochromic pellet by piezochromic multi-material injection.

These categories make it possible to use the pellets as coating in order to form a piezochromic pellet or a decoration, such as for example a set of piezochromic pellets produced by printing by screen printing of an altimetric scale on the frame, the latter being hollow and tight to have a known PRef pressure. This configuration allows the piezochromic pigment to see a pressure difference between the known PRef pressure in the framework and the external pressure felt.

They also make it possible to produce a pellet in the form of an insert, that is to say a hollow body impermeable to water and air, the cavity of which is at a known pressure PRef. This body can be made of a material including piezochromic pigments or be coated with an ink comprising said pigments. This coating can be a lacquer or a deposit in thin layers. This configuration makes it possible to have the piezochromic pigment seeing a pressure difference between the known pressure PRef in the hollow body and the external pressure felt.

The material used can be an organic or metallic or inorganic material, transparent or opaque, such as for example plastic or a resin or a glass.

In one example, the pellet is made of polymethyl methacrylate also called PMMA. This pellet is made of a double shell assembled and sealed by ultrasonic welding. This double shell is then coated by spraying with a 50 μm deposit of a polyurethane thermochromic lacquer containing a dispersion of piezochromic pigments. The piezochromic pigment represents 2.5% by mass of the mixture.

[0055] In a first embodiment, the covering element is a bezel 114 as shown in FIGS. 3 and 4. This bezel 114 can be a rotating bezel or a fixed bezel. In the case of a fixed bezel, this bezel may be a ring fixed to the middle part so as not to be able to rotate or be directly integrated into the middle part 104 and thus form a middle part-bezel.

[0056] Such a bezel 114 has a top wall 114a which is the face visible to the user and a vertical wall 114b allowing the user to rotate the bezel in the case of a rotating bezel.

In this embodiment, the pellets 122 of piezochromic pigment are arranged on the upper wall 114a acting as the visible face.

[0058] In the case where the pellets 122 are in the form of an ink or paint, these pellets are screen printed on said upper wall, the bezel being hollow. A scale can also be screen printed to associate a numerical indication with these piezochromic pellets. Of course, provision can be made for important values such as 0, 100m, 200m to be displayed by different pellets 122a.

In the case where the pellets are in the form of an insert, the upper wall 114a of the bezel 114 includes recesses (not shown). The number of recesses is the same as the number of inserts. The inserts can then be placed and fixed in the recesses by gluing, for example. However, it remains possible to directly overmold the inserts in the recesses. We then obtain a bezel having a bi-material appearance when a metal bezel has rubber inserts, for example.

[0060] Of course, it is possible to have several altitude sensors 120 on the bezel. For example, a first sensor would extend over the bezel in an arc of a circle going from the 9 o'clock position of the hour circle to the 3 o'clock position of the hour circle. A second sensor would extend over the bezel in an arc of a circle going from the 3 o'clock position of the hour circle to the 9 o'clock position of the hour circle. The first color of the first sensor may be chosen to be identical or different from the first color of the second sensor.

[0061] In the event that they are identical, it is advantageous to have 12 pellets 120, one per hour and it is advantageous to have different second colors. For example, the first color of the first and second sensors will be white; the first sensor allowing depth measurement will have a second color which will be blue while the second sensor allowing altitude measurement will have a second color which will be red.

[0062] In a second embodiment visible in FIGS. 5 and 6, the covering element is the ice 108 of the portable object. Such a crystal 108 is fixed to the middle part 104 and has an upper face 108a, a lower face 108b and a side edge 108c for fixing.

[0063] In this second embodiment, the piezochromic pellets 122 are arranged on the upper face 108a of the ice.

[0064] In the case of an ink or a paint, the tablets are screen printed on said upper face 108a. A scale can also be screen printed to associate a numerical indication with these piezochromic pellets. This scale can be screen printed on the bezel.

In one variant, the ice has hollows 108d of very low thickness. These hollows make it possible to place the piezochromic ink therein while ensuring a perfectly smooth ice surface 108, the risks of impacts flaking said ink are therefore reduced.

[0066] In the case where the pellets 122 are in the form of an insert, the upper face 108a of the ice 108 includes recesses 108d. The number of recesses is the same as the number of inserts. The inserts can then be placed and fixed in the recesses by gluing, for example.

However, it remains possible to directly overmold the inserts in the recesses. An ice is then obtained having a two-material appearance.

It is possible, for these two scenarios, for the piezochromic pellets 122 to be arranged on the upper face of the crystal but for the numerical indications of depth or altitude to be placed on the dial or under the crystal.

[0069] In a third embodiment visible in FIG. 7, the covering element is the middle part 104 of the portable object.

As for the first and second embodiment, the piezochromic pellets 122 in the form of ink or inserts are arranged directly on the middle part or in recesses on said middle part. The numerical depth indications can be screen printed on the caseband.

[0071] In a fourth embodiment, the covering element is the strap 110 of the watch. In fact, the timepiece is fitted with a bracelet attached to the middle part via two pairs of lugs.

In a first case visible in FIG. 8, the bracelet 110 consists of two bracelet strands 110a, each strand being attached to a pair of horns 112 and connected to the other strand via a clasp 111. Preferably, the bracelet strands 110a are made of rubber or plastic.

[0073] Several solutions are possible for the arrangement of the piezochromic pellets 122.

A first solution consists in screen printing the bracelet with a piezochromic ink or in coating certain areas with a piezochromic paint, this operation being carried out on a leather, plastic, metal or ceramic bracelet.

A second solution consists in using pellets as an insert and in placing and fixing these inserts in recesses made in the strand of the bracelet.

[0076] A third solution consists in screen printing a flexible medium with piezochromic ink. This flexible support then being inserted into the bracelet strand so that the pellets are visible.

[0077] In a second case visible in FIG. 9, the bracelet is made of metal and is then made up of a plurality of links 110b attached to each other by means of pins. This makes it possible to have links 110b which can pivot relative to each other.

[0078] This bracelet strand also consists of a clasp. This clasp is here in the form of a folding clasp 111.

[0079] The piezochromic pellets 122 in the form of ink or of inserts are then arranged at the level of the links 110b of said bracelet, directly on the bracelet or in recesses thereof.

Preferably, each link 110b carries a piezochromic pellet.

Even more preferably, the piezochromic pellets 122 are arranged on the links 100c located between the pair of horns at 6 o'clock and the folding clasp. Indeed, when a timepiece is on the user's wrist, the links 110b located between the pair of lugs located at 6 o'clock and the folding clasp 111 are the most accessible by the user. The latter just has to turn his wrist slightly to see them. They are even more visible when the user has their arms resting on a table or desk. This arrangement makes it possible not to overload the display of the dial by having pellets on the crystal or the bezel while offering good visibility.

[0082] In a fourth embodiment visible in FIGS. 10 to 12, the covering element is the clasp 111, that is to say the folding clasp of the bracelet. Such a folding buckle is generally made up of three parts 111 a, 111 b, 111 c like spars articulated with respect to one another. Two of these parts are attached to a link. These parts making up the folding clasp 111 are then designed to articulate so that they can stack up, these three parts 111a, 111b, 111c then becoming one. This configuration allows the length of the bracelet to be extended momentarily for attachment to the user's wrist.

For some models of folding clasp, one of the parts acts as the main part 111a because it is this part that accommodates the other two parts 111b, 111c, this so-called main part 111a is the part visible from the outside. From the outside, the user therefore sees a part in the shape of a metal plate on which indications such as the name of the brand can be engraved.

[0084] Advantageously, the present invention uses this surface for the arrangement of the altitude sensor. The piezochromic pellets 122 are therefore arranged on this surface of the central part 111a of the folding clasp as visible in FIG. 10.

[0085] The piezochromic pellets 122 can be aligned and associated with a scale of numerical indications. It is however possible that the pellets 122 are configured to have different sizes depending on the altitude as shown in FIG. 11. For example, the piezochromic pellets 122 may take the form of increasingly larger arrays as the depth increases or as the altitude increases. As a result, the user is able, without encrypted indication, to have reliable information.

In a variant visible in FIG. 12, it will be possible to have an extended scale. This extended scale has a central line from which the bars forming the piezochromic pellets 122 extend. These bars extend on either side of the line so that the bars used for depth measurement extend downwards while the bars for measuring altitude extend to the right.

In a variant of the invention, the piezochromic pigment is coupled to a fluorescent pigment in order to emit a more intense color in the presence of ultraviolet rays or to a phosphorescent pigment in order to absorb the energy of the visible spectrum and d 'emit intense color in the absence of light.

This characteristic allows the piezochromic pellet 122 to be luminescent and visible to the user under all circumstances. For example, this ability to react to ultraviolet or visible radiation makes it possible to have the pellets which are readable when diving in depth, in a dark environment.

It will be understood that various modifications and / or improvements and / or combinations obvious to a person skilled in the art can be made to the various embodiments of the invention set out above without departing from the scope of the invention defined by the appended claims.

Provision can also be made for the crown of the timepiece to have at least one piezochromic pellet. This patch can be configured so that the pressure at which it changes color corresponds to the maximum altitude or depth of said timepiece.

Claims (21)

A cladding element (1) of a timepiece comprising a reinforcement made of a first material, said cladding element further comprising at least one pressure sensor (120), characterized in that said sensor pressure is formed of at least one pellet (122), said pellet (122) being composed of a binder and a piezochromic pigment, said piezochromic pigment being chosen to react to a specific pressure so that said pigment passes from a first color to a second color when said specific pressure is reached. A cladding element according to claim 1, characterized in that said pressure sensor (120) is formed of a plurality of pellets (122), each pellet reacting to a specific pressure specific thereto. 3. Dressing element according to claim 2, characterized in that said pellets (122) all have the same first color. 4. Dressing element according to claim 3, characterized in that said pellets (122) all have the same second color. 5. Skin element according to claim 3, characterized in that said pellets (122) are designed so that their second color allows a gradient when they have all passed from the first color to the second color. 6. covering element according to one of the preceding claims, characterized in that said pressure sensor (120) allows the measurement of a positive altitude relative to the sea level. 7. Dressing element according to one of the preceding claims, characterized in that said pressure sensor (120) allows the measurement of a negative altitude relative to the sea level. 8. covering element according to one of claims 1 to 5, characterized in that said pressure sensor (120) allows the measurement of a depth under water. 9. cladding element according to one of the preceding claims, characterized in that the wafer (122) is in the form of an ink or paint or lacquer deposited on the armature, said armature being hollow pressure PRef known . 10. Dressing element according to one of claims 1 to 8, characterized in that the pellet is in the form of an insert formed of a hollow body waterproof and air, said body hollow being coated with said piezochromic pigment. 11. covering element according to one of claims 1 to 8, characterized in that the wafer (122) is in the form of an insert formed of a hollow body waterproof and airtight said piezochromic pigment being dispersed in the material forming said body. 12. Dressing element according to one of the preceding claims, characterized in that the armature comprises at least one recess in which the wafer (122) is arranged. 13. Skin element according to one of the preceding claims, characterized in that the armature is a telescope (114). 14. covering element according to one of the preceding claims, characterized in that the frame is an ice (108). 15. A dressing element according to one of the preceding claims, characterized in that the frame is a middle (104) box (102) watch. 16. Dressing element according to one of the preceding claims, characterized in that the frame is a bracelet (110). 17. Dressing element according to claim 16, characterized in that the bracelet comprises two strands (110a), said pressure sensor (120) being arranged on at least one of the two strands. 18. Cladding element according to claim 16, characterized in that the bracelet comprises a plurality of links (110b) hinged together, said pressure sensor (120) being arranged on at least one link. 19. Cladding element according to claim 16, characterized in that said bracelet is closed by a clasp (111) with a folding clasp, said pressure sensor being arranged on said clasp. 20. A trim element according to one of the preceding claims, characterized in that the armature is a crown. 21. Dressing element according to one of the preceding claims, characterized in that said piezochromic pigment is coupled to a luminescent pigment to emit a more intense color.