JP6567038B2 - Watch component having a surface with silk fibroin - Google Patents

Description

The present invention relates to a timepiece component of a timepiece movement , which is subject to friction and requires good tribological properties. However, the present invention is not limited to this. In particular, the present invention relates to a watch bearing, a gear train, an escapement, or a main spring.

  In the field of microtechnology, which will be more specifically shown later in the field of watchmaking, it is known to lubricate components that are subject to friction on the surface. Lubrication is generally achieved by applying an oil or grease based on hydrocarbons, fluorocarbons or silicon. But this solution is not without its drawbacks.

  Oils and greases undergo degradation of their lubricating power over time due to contamination and chemical changes, so any mechanism lubricated by these means is periodically disassembled, cared for and lubricated. Need to be done.

In the field of microtechnology and in particular in the field of watchmaking, there is a need for low-density structural materials that replace steel, nickel silver or commonly used metals. In particular, such materials make it possible to improve the energy efficiency of mechanical elements, in particular escapements and watch movements .

For this purpose, timepiece movements are known which use elements made of technical polymers, such as PEEK (polyetheretherketone). However, these solutions do not obtain the durability and reliability of traditional metal components.

  Silk is a famous natural fiber produced by silkworm larvae and has been traditionally used for thousands of years in the form of threads and fabrics.

  The mechanical properties of silk correspond to a protein called fibroin that forms the center of the yarn. Fibroin is a highly insoluble protein, which is composed for the main part (up to 90%) by the amino acids glycine, alanine and serine, and fibroin has extremely high fiber structure and mechanical resistance. I have. There are other natural fibers made from insects or spiders, which are rarely used, but they also contain fibroin and are known for mechanical quality. The present invention relates to a timepiece component with fibroin derived from all natural or artificial sources. Embodiments of the present invention can use fibroin obtained from silkworm moth moths or other lepidopterous larvae, moths, bacteria, yeasts, filamentous fungi, cell cultures, but not exclusively. In the context of the present invention, fibroin can be obtained from a genetically modified organism.

  The unique nature of fibroin has become a focus of attention, especially in the medical industry. For example, U.S. Patent No. 6,057,077 proposes a method for producing pure fibroin and its use as a biocompatible material and its use in medicine. U.S. Patent No. 6,057,031 describes the production of fibroin globules with, for example, a low dry coefficient of friction, which is for medical applications, i.e. for the treatment of joint pain. Patent Document 3 proposes forming by molding in order to make an implantable device that can be integrated with a living tissue, for example.

  Patent document 4 has described the coating material containing a silk particle. The paint is applied to the surface of the watch so that the surface is comfortable to touch.

International Patent Application Publication No. 2014014164 International Patent Application Publication No. 20131363407 International Patent Application Publication No. 2012145594 Japanese Patent Laid-Open No. 11-42106

One object of the present invention is to propose a component that can be used in a watch movement without the disadvantages of the known components, in particular with regard to lubrication and tribological properties.

The present invention relates to a component for a watch movement , the component having a surface subject to friction, at least part of which is formed from a material containing fibroin.

  Fibroin can be applied (formed) as a thin layer to the surface of the component, or the component itself comprises a composite material containing fibroin in a suitable matrix. However, the present invention also relates to a component formed entirely from fibroin.

  In the context of the present invention, fibroin can be used in pure form or in combination with functional additives that allow its performance to be enhanced, for example plasticizers, adhesives, lubricants. The lubricants include, for example, mineral oils, glycerins, lipids, solid lubricants or all other suitable lubricant materials, pigments, and the like.

  With respect to the elements made, the present invention can be applied to all elements of a watch that are moving or subject to friction. By way of illustration, reference can be made to the working surface of a wheel, in particular a gear. A jewel or simple bearing and a disc pivot fitted into it. The escapement elements include escapement wheel teeth, pallet stone, pallet forks and darts, balance pins and rollers, main spring and spring case. But this list is far from complete.

  Illustrative embodiments of the invention are illustrated in the description illustrated by the attached figures.

1 shows a watch escapement system according to one embodiment. 1 shows a watch receiver according to one embodiment.

The present invention will be described with reference to the components for the watch movement shown in FIGS. For ease of explanation, this example specifically refers to an escapement system, but it is understood that the present invention is not limited to this particular embodiment and encompasses any watch component that is subject to friction. It is necessary to keep.

  In the embodiment shown in FIG. 1, an escapement system 1 for a watch can be seen. The escapement system 1 has in particular an escapement plate 3, which has an escapement wheel fixedly integrated with the escapement pinion, the escapement pinion being pivoted. The pallet 2 is mounted in a pivoted state on the pallet staff 23, and the roller 4 is driven on the balance staff 40. The roller 4 includes a small wheel 41 with a notch 42 and a large wheel 43 with a peg (not shown in FIG. 1). The pallet 2 is provided with an arm 21, which has a pallet 22 that acts with the teeth 31 of the escapement plate 3. On the opposite side to the arm 21, the lever 20 includes a dart 24 and a fork 25. The dart 24 is designed to work with the small wheel 41 to prevent inadvertent displacement of the fork 25. The fork 25 is attached together with the darts 24 in a vertically aligned state, and follows the rotation of the peg, and the pallet 2 is pivoted around the pallet staff 23 in the forward and backward movement. Two horns designed to contact the pegs of the large wheel 43 are provided for driving.

  The escapement system is difficult to develop because it is a compromise between the smallest possible inertia and the largest possible tribological property, particularly of the pallet stone 22 and the fork 25. It is therefore difficult to avoid sticking between the wheel peg and the horn 26 of the fork 25 while maintaining minimal inertia and further no response to the magnetic field.

  According to one aspect of the present invention, at least some of the plurality of disks are preferably coated with a layer with fibroin to change their friction. The layer with fibroin may be, for example, a solid layer deposited by evaporating and drying an aqueous solution of fibroin, or a liquid or colloidal layer, in which fibroin particles are contained within a liquid or gel matrix. It is suspended in suspension.

  Fibroin layers are additives intended to enhance tribological properties, such as lubricants, glycerin, plasticizers, adhesives, pigments or substances whose purpose is to inhibit fibroin degradation Is included.

  According to another aspect of the invention, fibroin may be a functional component of a composite material in the form of a solid matrix, for example made of resin. In a variation of this embodiment, the composite material may be a fibroin matrix and further forms of fibroin material reinforcement.

  If fibroin is present in the form of dispersed particles in the form of a solid matrix, liquid matrix or gel matrix, the particles may be microspheres, needles, fibers or particles in any form.

  In another alternative embodiment, the watch component of the present invention may be made from a solid monolithic block with fibroin as the primary or secondary material. Such a block can be obtained, for example, by dissolving a powder of fibroin material at high temperature and high pressure.

  The components of the present invention may be coated with a fibroin fiber fabric or mesh, optionally including additives, in various embodiments.

  In a possible embodiment, the entire surface of the component can be coated with a layer containing fibroin. However, it is possible to coat only a part of the disc. For example, the pallet 2 can only be coated in the area of the fork 25 and the pallet 22. With this configuration, the fork 25 and the pallet stone 22 are less worn and have a smaller coefficient of friction in relation to the pegs. In another embodiment, the escapement wheel 3 can be coated in the region of the teeth 31. Similarly, the roller 4 can be coated with a layer containing fibroin only in the peg region of the large wheel 43.

  When the present invention comprises a thin layer of fibroin, the substrate on which the layer is deposited is the technology currently used in watchmaking and the materials currently used in watchmaking, such as steel, brass, nickel, silver or titanium. Can be made using. However, if fibroin is used as a solid block of a composite material or as a functional component (reinforcement and / or matrix), the component according to the invention is made entirely from this material or partly fibroin. It will be made from the material it contains.

  In one embodiment, a component whose surface contains fibroin is used to manufacture a watch component that is fixed but subject to friction. Such components include a watch chassis, eg, a plate and / or receptacle that is used to support other movable elements (not depicted in FIG. 2) of the watch. Illustratively, FIG. 2 depicts a watch receiver 50. The component 50 is made of steel, brass, nickel silver, titanium or other suitable material.

  Further in accordance with the present invention, component 50 can be at least partially coated with a layer containing fibroin to modify tribological and / or frictional resistance characteristics. For example, the disk, particularly the part supporting the part 52 of the component into which the disk pivot is driven, can be coated. Furthermore, the wall of the hole 51 forming the bearing can be coated with a layer containing fibroin, so that the coefficient of friction on the wall of the hole is reduced and the bearing and itself are coated with fibroin. The friction torque between the disc arbor that can be improved is improved. In this way, it is possible to pass a ruby bearing (jewel bearing), on which the pivot is normally mounted.

  According to a different embodiment, the holes 51 forming the bearing are made seamlessly with a material containing fibroin which is fixed onto this receptacle 50.

  The advantage of the component 50 according to the present invention is that it can provide a plate and receptacle that are much thinner. Accordingly, it is possible to manufacture a thinner watch. Another advantage is that it is possible to make single piece components (chassis, plates and / or receptacles) with high accuracy, while at the same time avoiding the disadvantages induced by the assembly process (juwelling) .

An embodiment of the present invention is the use of a material containing fibroin in a component of a watch movement . The process for producing a solid component as a coating or composite comprises two steps. The first step is to adjust the experimental conditions so that the raw material can flow or be released to form the object. This first step means making a particularly suitable protein solution. The second step consists in adjusting the state of the raw material in order to bring the raw material into a gel state or to bring the raw material close to the sol-gel transition point.

  The treatment requires one or several solvents to bring about the degradation of silk fibroin, which may be, for example, an aqueous solvent, a fluorinated solvent, an ionic liquid or a stronger acid. However, some of the fibroin is insoluble and is suspended in suspension in the solution. This solid is preferably separated from the solution, for example by centrifugation or by pressure filtration.

  Following the decomposition process, additives can be added. These additives may be, for example, colored pigments, anti-use inserts, polymers, lipids or oils, powders, surfactants and the like. At this stage, for example, for the purpose of a special tissue, i.e. to make a composite, or to change the chemical and physical properties of the resulting material, the first solution may contain a second solution or a plurality of solutions. It is also possible to mix these solutions.

  After the fibroin decomposition step, the material is molded. As an excerpt list, molding can be done in a single solid form of capsules, spheres, fibers, foams, jellies, or a combination thereof. Molding of the different structures described above can be done by many methods such as casting, spinning, electrospinning, projection or even (extractively) precipitation, or in the form of a monolithic structure by molding. it can.

Due to its self-lubricating properties, it is advantageous that the developed material can be replaced with liquid lubricants conventionally used in watchmaking movements . Tests performed on the material of the present invention yield a dynamic coefficient of friction as low as 0.03 for a contact pressure of 50 MPa while in contact with steel at relative speed conditions in the order of mm / s. This low coefficient is maintained for a considerable friction distance (> 1 km). Otherwise, with all other conditions being equal, this dynamic friction coefficient is lower than the friction coefficient measured in the case of diamond-to-diamond contact.

  While the use of components acting in dry lubrication, compared to the high humidity lubrication traditionally used in the watchmaking field, makes it possible to reduce the time required to clean, drain and lubricate the mechanism The warranty period is extended.

As being complementary roles of tribological properties, the density of the steel lower density of this material as compared to (about 7 g / cm ³⁾ (about 1.2 g / cm ^3), transfer performance (in particular the moment of inertia Can be increased) and thus the overall working capacity of the watch movement is increased.

  For comparison purposes, the density and mechanical properties of the components, in particular their Young's modulus (about 12 GPa) and their hardness (about 30 HV), are close to the mechanical properties of plastic parts of polyetheretherketone (PEEK) s. However, the tribological properties are particularly excellent in terms of friction and wear coefficient.

  The components to be developed successfully demonstrate chemical-resistant watchmaking and climate tests, especially synthetic sweat tests, salty fog tests or even tropical climate tests.

1 escapement system 2 pallet 20 lever 21 arm 22 pallet stone 23 pallet staff 24 darts 25 fork 26 horn 3 escapement plate 30 escapement axle 31 escapement wheel teeth 32 hub 4 roller 40 temp staff 41 small wheel 42 Notch 43 Large wheel 50 Receiving 51 Hole 52 Portion

Claims (15)

A component for a watch movement, the component having a surface that is subject to friction with other movable components of the watch movement , at least a portion of the surface comprising fibroin A watch component characterized in that it is made of a material. The surface subject to friction is the surface of the pivoting staff mounted on the bearing, the rest of the bearing set to accommodate the pivoting staff, the impact surface of the escapement, the pallet pallet The component according to claim 1, wherein the component is one of a surface, a tooth contact surface, a main spring surface, and an inner surface of the mainspring case. The component of claim 1, wherein at least a portion of the surface is coated with at least one layer of fibroin or with an assembly of woven or meshed fibroin fibers. 2. Component according to claim 1, characterized in that the material is a composite material comprising particles and / or microspheres and / or microparticles and / or fibroin fibers in a polymer, synthetic or metal matrix. . 2. Component according to claim 1, characterized in that fibroin is contained in a solid matrix, in particular of a resin. The component of claim 1, wherein the fibroin is in the form of a gel. The component of claim 1, comprising a solid fibroin element. 4. A component according to claim 3, wherein the coating has a thickness comprised between 2 and 100 [mu] m. 2. Component according to claim 1, characterized in that the fibroin material comprises an additive intended to enhance tribological properties. At least a portion of the surface is coated with at least one layer of fibroin or with an assembly of woven or meshed fibroin fibers, the component being fixed to a watch chassis that supports at least one movable element. The component according to claim 1, wherein the component is formed. At least a portion of the surface is coated with at least one layer of fibroin or with an assembly of woven or meshed fibroin fibers, the component being an arbor supported by a fixed component of the watch chassis. 2. A component as claimed in claim 1, characterized in that it forms a movable element which is adapted to be pivotally mounted on. The component of claim 1, wherein the component is made entirely from a material comprising fibroin. An escapement system for a watch movement, comprising a component having a surface that is subject to friction with other movable components of the watch movement , at least a portion of which surface contains fibroin At least a portion of the surface is coated with at least one layer of fibroin or with an assembly of woven or meshed fibroin fibers, and the component comprises an escapement wheel An escapement characterized in that it is one of the escapement elements and the surface receiving friction in one of teeth, pallets, forks, pallet darts, pegs, temp rollers, main springs and mainspring cases. system. In a timepiece movement comprising at least one component having a surface that is subject to friction with other movable components of the timepiece movement, at least a portion of this surface is formed of a material containing fibroin. Clock movement. A timepiece comprising at least one component for a watch movement, wherein the component has a surface that is subject to friction with other movable components of the watch movement , at least a portion of which surface contains fibroin. A watch made of the material it contains.

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