This application claims priority from European Patent application No. 13160024.9 filed Mar. 19, 2013, the entire disclosure of which is hereby incorporated by reference.
The invention concerns a timepiece mechanism cassette including at least one bearing surface for positioning said cassette in a movement and at least one bottom plate and one top bar, at least said plate or said bar being rigid, between or on which there are arranged functional components at least two of which are movable relative to each other, and between said plate and bar there is pivoted or moved at least one said pivotally or shiftably movable functional component, wherein said bottom plate and/or said top bar forms an inseparable single-piece component with at least one of said functional members, and wherein at least one said pivotally movable functional component is pivoted between said plate and said bar, on either side of said functional component.
The invention also concerns a mechanical timepiece movement including at least one cassette of this type.
The invention concerns the field of timepiece mechanisms, and more specifically movements integrating ready-to-use functional modules.
The use of modular assemblies permits the manufacture of families of products using a common base, each personalised by different options or functions, notably complications in the case of a mechanical timepiece movement.
The concept of extremely high precision modules or cassettes allows large scale production to be combined with high quality goods.
Thus, modular sub-assemblies for timepiece movements are known, from
EP Patent Application Nos 11193173.9 and 11193174.7 in the name of ETA SA. The mechanical modules disclosed in these Patent Applications are irreversibly pre-adjusted and assembled to ensure the durability of their settings.
NL Patent No 11224C in the name of WATSON and WEBB describes an escapement mechanism housed inside a U-shaped oscillating pendulum block, between the leaves of which a support arbour for a straight balance is movable in a limited manner, in two lateral holes shaped in the arc of a circle, said arbour also pivoting and carrying the pallets, the escape wheel being pivoted in a cantilevered manner in a bore common to the oscillating block and to a fixed structure.
U.S. patent Application Ser. No 5/800,46A in the name of HARRINGTON also describes a U-shaped structure, whose flanks carry mobile component bearings, in particular for the pallets or components of the escapement mechanism.
U.S. Pat. No. 3,582,162A in the name of BAERMANN describes a magnetic bearing, of the electrical counter type, carrying a balance housed between two arms of a U-shaped armature.
However, in a conventional embodiment, the modules do not always allow for a reduction in the number of components, which would both reduce production costs and simplify the assembly plan, enabling mid-level technical personnel to assemble and adjust the most complex functions.
Thus, the invention proposes to provide modules, preferably in the form of cassettes, with a reduced number of components and having average assembly and adjustment complexity.
The present invention utilises, for this purpose, the new micro-component manufacturing technologies, MEMS, “LIGA”, lithography and suchlike, to optimise the manufacture of the modules, shown here as cassettes. These cassettes may be irreversibly assembled to each other as in the above two Patent Applications, or positioned and assembled in a conventional manner.
The invention concerns, on one hand the composition of the cassettes, with a reduction in the number of components by the combined integration of several components in the form of a single-piece sub-assembly, and on the other hand, more specifically, the attainment of the largest possible number of functions in a single-piece on a plate or bar.
The invention therefore concerns a timepiece mechanism cassette including at least one bearing surface for positioning the cassette in a movement and at least one bottom plate and one top bar, at least said plate or said bar being rigid, between or on which there are arranged functional components at least two of which are movable relative to each other, and between said plate and bar there is pivoted or moved at least one said pivotally or shiftably movable functional component, wherein said bottom plate and/or said top bar forms an inseparable single-piece component with at least one of said functional members, and wherein at least one said pivotally movable functional component is pivoted between said plate and said bar, on either side of said functional component, characterized in that said at least one said functional component pivoted between said plate and said bar forms an inseparable single-piece component with said bottom plate and/or said top bar.
According to a feature of the invention, said inseparable single-piece component includes an elastic return means for performing a return function.
According to a feature of the invention, said cassette is an escapement mechanism cassette, and said functional components are formed by at least one regulator member pivoted between said plate and said bar on pivots, at least one escape wheel, a first elastic return means, and at least one means of intermittently locking said at least one escape wheel cooperating with said at least one regulator member which is moved in a reciprocating motion under the action of the first elastic return means.
The invention also concerns a mechanical timepiece movement including at least one cassette of this type.
The advantage of making components in a single-piece, and in particular with the plate or the bars, is that the number of parts is reduced, and assembly problems are avoided. The invention benefits from the precision with which these monolithic components are made (typically, the parts are for example made of silicon and therefore enjoy micrometric precision).
The monolithic cassette has the main advantage of guaranteeing the distances between centres and of forming a ready-to-use mechanism, in particular an oscillator in a preferred application.
The invention incorporates, in particular, flexible guide members, which have the following advantages:
The fabrication of these flexible guide members results in limitations, notably a limited travel, low return forces, and a limited load. However, these limitations are not prohibitive for a number of horological functions, in particular those which relate to regulation.
These limitations are amply compensated by the high precision of the distance between centres, the small number of components to be made and hence the reduced complexity and assembly time. A cassette according to the invention has a great industrial advantage: the mechanism cassette, particularly an oscillator, forms a component ready for assembly in a movement. Further, there is nothing to prevent an entire movement being devised in the form of a cassette of the invention.
Other features and advantages of the invention will appear upon reading the following detailed description, with reference to the annexed drawings, in which:
The invention concerns the field of timepiece mechanisms, and more specifically movements integrating ready-to-use functional modules.
The invention concerns a timepiece mechanism cassette 1, including at least one bearing surface 101 for positioning the cassette in a movement 100, and at least one bottom plate 2 and one top bar 3, at least the plate 2 or bar 3 being rigid, i.e. including at least one area, carrying a bearing surface 101 of this type, which is sufficiently rigid to allow cassette 1 to be handled and operating precision to be maintained, in addition to the dimensional precision of the distance between centres of the functional components 10 comprised in said cassette 1, during the assembly of cassette 1, during the handling thereof, and after the integration thereof in movement 100.
Functional components 10 are arranged between or on plate 2 and bar 3. At least two of these functional components 10 are movable in relation to each other.
At least one pivotally or shiftably movable functional component 10 is pivoted or moved between plate 2 and bar 3.
According to the invention, the bottom plate 2 and/or top bar 3 forms an inseparable single-piece component 20 with at least one of functional members 10.
In a particular embodiment, at least one functional component 10 is pivotally movably mounted between said plate 2 and said bar 3 in which it is pivoted directly or via bearings.
In a particular embodiment, at least one functional component 10 which is pivoted between plate 2 and bar 3 forms an inseparable single-piece component 20 with bottom plate 2 and/or top bar 3.
In a particular embodiment, at least one functional component 10 is pivotally movably mounted between said plate 2 and said bar 3 in which it is pivoted directly or via bearings.
The following description will focus on single-piece embodiments, which are the most advantageous. This in no way prevents the attainment of a cassette of the invention with certain added components, which may be more advantageous in terms of cost in some particular cases.
Advantageously, this inseparable single-piece component 20 includes an integrated elastic return means for performing a function of energy distribution and/or regulation and/or return and/or damping and/or locking in an adjustment position.
In a particular embodiment, the integrated elastic return means includes at least one flexible bistable or multi-stable element, as seen for example in
B where it is detached therefrom.
To allow this type of cassette 1 to be easily pre-adjusted, at least one of functional components 10 is position adjustable and is lockable in a pre-adjusted position by a locking means.
In a particular, non-limiting application, more particularly illustrated in the Figures, cassette 1 is an escapement mechanism cassette, and functional components 10 are formed by at least one regulator member 4, such as a balance, pivoted between plate 2 and bar 3 on pivots 45 and 44, at least one escape wheel 5, a first elastic return means 7, such as a balance spring, and at least an intermittent clamping means 6, such as a pallet lever, for intermittently clamping said at least one escape wheel 5, and cooperating with said at least one regulator member 4, which is moved in a reciprocal motion under the action of first elastic return means 7.
Pivots 44, 45 may be formed by conventional pivots or by flexible guide members.
In a particular embodiment, as seen in particular in
In a particular embodiment, the first elastic return means 7 includes a balance spring 71 whose outer end is fixed to a stud 73 in a single-piece with top bar 3.
In the
The adjustment of the active length of the outer coil of balance spring 71 may be achieved in various manners.
In a variant, the outer coil 77 of balance spring 71 is clamped by two pins 74A, 74B in a single-piece with top bar 3.
In another variant, at least one of pins 74 is secured to the top bar 3 by a second elastic return means 76, which is in a single piece with said at least one pin 74A or 74B and bar 3, and which tends to move said pin closer to the other pin 74B or 74A.
In an embodiment without any play, as seen in
This elastic return means 76 is formed, in particular, of one or more flexible elements, located either in the plane of balance spring 71, or in the plane of bar 3, or in any other plane. In an advantageous variant, balance spring 71 and/or pins 74A or 74B may be notched locally to allow for discrete, notch-by-notch adjustment.
In another variant, balance spring 71 is held in a flexible index 74 of this type with pins 74A and 74B. Index 74 is in a single piece with bar 3, although balance spring 71 is not necessarily in a single piece with stud 73 or with bar 3.
In a particular embodiment, the intermittent clamping means 6 forms an inseparable single-piece component 20 with bottom plate 2.
In a conventional application, intermittent clamping means 6 is a pallet lever 61 in a single-piece with plate 2 to which it is connected by a third elastic return means 65.
This pallet lever 61 has a top part 62 carrying pallet stones, horns and a dart. In a particular embodiment, the pallet lever is added and fixed to a bottom part 63 which is in the plane of plate 2 to which it is connected by a third elastic return means 65 which is also in the plane of plate 2.
In another variant, pallet lever 61 includes a top part 62 carrying pallet stones, horns and a dart in one or more parts 62A, 62B. This top part 62 is in a single-piece with a bottom part 63 and extends above it towards bar 3. Bottom part 63 is in the plane of a plate 2 to which it is connected by a third elastic return means 65 which is also in the plane of plate 2.
In the variant of
In the
In the
In the
Advantageously, in these different variants, plate 2 incorporates pins or solid banking pins limiting the clearance of the pallet lever, which are in a single piece with said plate 2.
In general, the incorporation of limiting elements, regardless of whether they are in plate 2, bar 3 or another inseparable single-piece component 20, is an advantage of the invention.
The design of cassettes 1 according to the invention including inseparable single-piece components 20 also optimises the pivoting of the various mobile components and, as required, ensures the parallelism thereof, or conversely permits at least one end of a mobile component arbour to be moved to perform a micrometric setting adjustment.
The action on the pivot points permits, in particular, the distance of centres between the mobile components to be adjusted to adjust the penetration of the toothings and/or lifting pieces. The distance of centres adjustment may be carried out in a monolithic manner with the plate or the bar. This principle of adjusting the distance between centres is valid for all the distances between centres in a movement.
In this
Naturally, it is also possible to envisage a variant wherein this component is pivoted at both ends in suspended bearing carriers.
The fourth elastic return means 14 allows for a range of adjustment, the return means is preferably associated with a post-adjustment position locking means, an example of which is given in the present description in the particular case of
In a particular embodiment visible in
In a variant, the top element 3A of bar 3 forms the whole of bar 3, and/or bottom element 2A of plate 2 forms the whole of plate 2.
In a particular embodiment visible in
To maintain the operating position corresponding to minimum distance
EMIN, plate 2 includes snap fit means 22 arranged to cooperate, in the proximate position only, with a complementary snap fit means 32 comprised in bar 3 for holding plate 2 and bar 3 in the proximate position.
Preferably, plate 2 then includes a guide means 21 cooperating, in any position, with a complementary guide means 31 comprised in bar 3, for a parallel relative movement of plate 2 with respect to bar 3.
In a particular embodiment, cassette 1 includes at least one pivotally movable functional component 10 between a bottom pivot 45 integral with plate 2 and a top pivot 4 integral with bar 3, between which the pivotally movable functional component 10 is freely inserted in the distal position, and between which it is mounted, axially confined and free to pivot in the proximate position.
For a particularly advantageous application to a mechanism which is adjustable and lockable, notably in a reversible manner, but which can also be locked (notably irreversibly) after an initial adjustment, at least one inseparable single-piece component 2 includes a position adjustable mechanism 80.
This position adjustable mechanism 80 includes a rigid structure 81 which carries, via at least one elastic strip 83, a position adjustable component 82. This rigid structure 81 may be plate 2, bar 3 or any of the inseparable single-piece components 20 comprised in cassette 1.
In the case of
This clamping mechanism 94 is resiliently secured to structure 81 by at least one flexible element 96 and is preferably in turn subject to the action of a locking mechanism which allows mechanism 94 to occupy either a detached position in which adjustment mechanism 90 is free, or an engaged position in which clamping mechanism 94 hinders adjustment mechanism 90. This locking mechanism includes at least one flexible element 98 forming a jumper and resiliently secured to structure 81, said at least one flexible element 98 here includes a beak 99 which cooperates with a beak 97 of clamp 94 to hold the clamp away during the position adjustment, or with a complementary stop surface 95 of clamp 94 as security for the clamp when the position adjustment is carried out. The latter is in the form of a fork so as to limit the travel of an arm 93 comprised in comb 91.
As seen above, this combined adjustment, clamping and locking mechanism, illustrated here for a particular application of adjusting a stud on a travel concentric to the arbour of a balance spring, is applicable to a wide range of applications: positioning a bearing, a stop member, or other element.
In a particular embodiment, visible in
In the non-limiting variant of
This architecture of
Advantageously, cassette 1 includes a flexible play take-up means for confining without play each said arbour 47 of each said pivotally movable functional component 10 comprised in cassette 1.
In an advantageous embodiment, cassette 1 is made of silicon. The pivot points of housings 460 are defined, for example, by anisotropic (KOH) etches in a silicon substrate. A version with an assembly of jewels is also possible. The great advantage is the very precise positioning of the pivot points (distance from centres, verticality). It is noted that placing cover 18 in position does not disrupt the positioning of the various arbours.
In another particular embodiment of the invention, bottom plate 2 and/or top bar 3 and/or frame 17 forms an inseparable single-piece component 20 with at least one shockproof bearing for receiving a pivot of a component of the mechanism incorporated in cassette 1, particularly an escapement mechanism.
In the particular embodiment of
The shock absorbers may thus be partially or totally made inside the plate: the shock absorber spring may be made jointly with the plate. One of the two (or both) jewels may be made jointly with the plate. The pivoting then occurs directly in the silicon. The pivot points may be made straight in the silicon with DLC or other surface coatings. There are thus no longer any jewels and the points of rotation are very precisely positioned.
In a particular embodiment, inseparable single-piece component 20 includes severable elements intended to facilitate the assembly of the component in a larger assembly, the severable elements then only need to be broken off to give one or more degrees of freedom to some of its constituent parts. In a particular embodiment, at least one of movable functional components 10 comprised in cassette 1 is integral with at least one linear flexible guide member which is in a single piece with plate 2 and/or bar 3.
In another particular embodiment, all the movable functional components 10 comprised in cassette 1 are each integral with at least one flexible linear guide member which is in a single piece with plate 2 and/or bar 3.
In an advantageous embodiment of cassette 1 according to the invention, the inseparable single-piece component 20 is made of micromachinable material, or silicon, or silicon oxide, and the integrated elastic returns means of the inseparable single-piece component is pre-stressed in a silicon oxide state. Other materials in MEMS or “LIGA” technology may be employed. Quartz, DLC, at least partially amorphous materials or metallic glasses, may be used for these applications, although the list is not limiting. Diamond, ruby or corundum may also be used.
Particular structuring of plate 2 and/or bar 3 and/or the inseparable single-piece components 20 may compensate the effects of expansion of these structural elements or components of the mechanism of cassette 1. It is, for example, possible to make the plate in silicon, and then oxidise it, for the sake of consistency.
Number | Date | Country | Kind |
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13160024.9 | Mar 2013 | EP | regional |