Escapement mechanism for timepiece

Abstract

The invention relates to an escapement mechanism (10) for a timepiece, comprising a first escapement gear (12) rotatably mounted about a first axis of rotation (A1) and comprising a gear train equipped with a first tooth (121) and a second tooth (111), a second escapement gear (22) rotatably mounted about a second axis of rotation (A2) and comprising a gear train equipped with a first tooth (121) and a second tooth (111), and comprising a gear train arranged to cooperate with at least the second teeth (111) of the first escapement gear (12), characterized in that each second tooth (111) of the first escapement gear (12) has an arm shape comprising at least one end projection (111a) arranged to cooperate with the gear train of the second escapement gear (22).

Description

TECHNICAL FIELD

[0001] The present invention relates generally to an escapement for a mechanical timepiece. The present invention relates in particular to an escapement comprising two escape wheels. An aspect of the present invention can relate to an escapement comprising a plurality of escape wheels arranged to provide an impulse force, in particular a tangential impulse force, to an escape fork of a mechanical timepiece escapement. BACKGROUND

[0002] As shown in patent application EP4198641, in the prior art of escapements, a natural escapement is known comprising two escape wheels, wherein each escape wheel is arranged to cooperate with an anchor-type escape fork on the one hand and with an impulse pallet jewel arranged on the balance on the other hand, to ensure a direct cooperation with one or the other of the two escape wheels. However, such an escapement is bulky and comprises complex mechanisms. SUMMARY

[0003] To solve the above-mentioned drawbacks of the prior art, first of all, the present invention aims at providing in particular an escapement (or more particularly an escape wheel) which is compact in structure, and / or which is not equipped with complex components to be manufactured and / or assembled, and / or which is robust and durable, and / or which is efficient in operation.

[0004] To this end, a first aspect of the present invention relates to an escapement for a timepiece, the escapement being arranged to receive a driving force from a driving wheel of the timepiece and to deliver an impulse force to maintain an oscillation of an oscillator of the timepiece, the escapement comprising:

[0005] a first escape wheel rotatably mounted about a first rotation axis and comprising a train of wheels equipped with first teeth and second teeth, the first teeth being arranged to deliver at least the impulse force to maintain the oscillation of the oscillator,

[0006] a second escape wheel rotatably mounted about a second rotation axis and comprising a train of wheels arranged to deliver at least the impulse force to maintain the oscillation of the oscillator and to cooperate with the second teeth of the first escape wheel,

[0007] characterized in that each second tooth of the first escape wheel has an arm shape comprising at least one end protrusion arranged to cooperate with the train of wheels of the second escape wheel.

[0008] In the above embodiments, the escapement comprises a first escape wheel comprising a gear train equipped with first teeth and second teeth different from the first teeth in shape and / or size and / or number, etc. The first teeth are arranged to cooperate with the at least one pallet (typically involved in blocking and / or transmitting the impact force). The second teeth are arranged to cooperate with the gear train of the second escape wheel (typically used to participate in driving and / or blocking the second escape wheel). To this end, each second tooth of the first escape wheel has an arm or bifurcated shape comprising at least one end protrusion, which enables each second tooth to cooperate with the gear train of the second escape wheel by its end, thus minimizing the inertia while allowing a large number of first and / or second teeth to be provided. Thus, the rest of the second tooth (i.e. the rest or shape of the second tooth) can be of minimal size. Thus, each second tooth of the first escape wheel has at least one end protrusion, which enables each second tooth to cooperate with the second escape wheel, thus enabling to maximize the thickness of the first escape wheel and / or to minimize the thickness of the second teeth and / or to maximize the number of escape teeth.

[0009] The escapement can have the following individual features or combinations of features.

[0010] In one embodiment, the gear train of the second escape wheel comprises first teeth arranged to transmit at least the impact force to maintain the oscillation of the oscillator and second teeth arranged to cooperate with the gear train of the first escape wheel, wherein each second tooth of the second escape wheel has an arm shape comprising at least one end protrusion arranged to cooperate with the gear train of the first escape wheel.

[0011] In one embodiment:

[0012] The second teeth of the first escape wheel are arranged to cooperate with the first teeth of the second escape wheel, the cooperation between the second teeth of the first escape wheel and the first teeth of the second escape wheel being achieved only by the end protrusions of the second teeth of the first escape wheel,

[0013] and / or

[0014] The second teeth of the second escape wheel are arranged to cooperate with the first teeth of the first escape wheel, the cooperation between the second teeth of the second escape wheel and the first teeth of the first escape wheel being achieved only by the end protrusions of the second teeth of the second escape wheel. That is, the rest of the second teeth of the first escape wheel or the second escape wheel (i.e. the rest or shape of the second teeth) does not cooperate with the first teeth of the second escape wheel or the first escape wheel, respectively. Thus, the shape and / or size and / or dimensions of the rest of the second teeth can be adjusted without having to take into account the cooperation with the first teeth.

[0015] In one embodiment:

[0016] The end protrusion of each second tooth of the first escape wheel is configured to mate with only the first teeth of the second escape wheel,

[0017] and / or

[0018] The end protrusion of each second tooth of the second escape wheel is configured to mate with only the first teeth of the first escape wheel. That is, the rest of the second teeth of the first escape wheel or the second escape wheel (i.e. the rest of the second teeth or shape) does not mate with the first teeth of the second escape wheel or the first escape wheel respectively, while the end protrusion of the second teeth of the first escape wheel or the second escape wheel mates with the first teeth of the second escape wheel or the first escape wheel respectively. Therefore, the shape, size and dimension of the rest of the second teeth can be adjusted without considering the mating with the first teeth; and the shape, size and dimension of the end protrusion of the second teeth has no effect on other components or parts of the escapement.

[0019] In one embodiment, the escapement comprises an escape lever configured to:

[0020] reversibly block the rotation of the first escape wheel and / or the second escape wheel,

[0021] receive the impact force from the first escape wheel and / or the second escape wheel and transmit it to the oscillator to maintain the oscillation of the oscillator. That is, the escape lever is disposed between each escape wheel and the oscillator. Therefore, in one embodiment, the escapement is an indirect impact escapement: the escape wheels do not mate directly with the oscillator.

[0022] In one embodiment:

[0023] The first teeth of the first escape wheel have tooth tips configured to mate with only the escape lever,

[0024] The first teeth of the second escape wheel have tooth tips configured to mate with only the escape lever.

[0025] In one embodiment, each of the at least one end protrusion of the first escape wheel has a first engagement portion configured to contact the gear train of the second escape wheel when each second tooth of the first escape wheel mates with the gear train of the second escape wheel,

[0026] and each first engagement portion is disposed between two circles having diameters of DTDD1 and 0.94.DTDD1, preferably between two circles having diameters of DTDD1 and 0.96.DTDD1, preferably between two circles having diameters of DTDD1 and 0.98.DTDD1, DTDD1 being the addendum circle diameter of the second teeth of the first escapement wheel. That is to say, each end protrusion and / or each first engagement portion is disposed at or close to an end of the second teeth.

[0027] In one embodiment, each first engagement portion comprises:

[0028] at least one circular surface, preferably convex and / or protruding, and / or

[0029] at least one flat surface, and / or

[0030] at least one edge, and / or

[0031] a pointed end.

[0032] In one embodiment, each second tooth of the first escapement wheel has at least one second engagement portion, said at least one second engagement portion being disposed in contact with the gear train of the second escapement wheel when each second tooth of the first escapement wheel is in gear with the gear train of the second escapement wheel,

[0033] and the second engagement portion is disposed at least partially between two circles having diameters of DTDD1 and 0.50.DTDD1, preferably between two circles having diameters of 0.95.DTDD1 and 0.60.DTDD1, preferably between two circles having diameters of 0.90.DTDD1 and 0.70.DTDD1, DTDD1 being the addendum circle diameter of the second teeth of the first escapement wheel. Thus, each second engagement portion is closer to the center of the escapement wheel than each first engagement portion.

[0034] In one embodiment, each second engagement portion comprises at least one convex contact surface. In one embodiment, each second engagement portion can comprise an involute portion.

[0035] In one embodiment, each second tooth of the first escapement wheel has a first side and an opposite second side, said at least one end protrusion being disposed on or at a side of the first side, and said at least one second engagement portion being disposed on or at a side of the second side.

[0036] In one embodiment, each second tooth of the first arm-shaped escapement wheel has:

[0037] a second tooth root defining a second tooth root circle diameter DPDD1,

[0038] a second tooth thickness EDD1,

[0039] a second tooth tip defining a second tooth tip circle diameter DTDD1,

[0040] and, from the second tooth root to the second tooth tip, the second tooth thickness EDD1 varies by less than 40%, preferably less than 30%, more preferably less than 20% compared to the second tooth thickness EDDPr1 measured at the second pitch diameter DPrDD1, defined as follows:

[0041] DPrDD1 = (DPDD1 + DTDD1 ) / 2

[0042] In the above embodiment, each second tooth of the first escapement wheel can have the shape of a bifurcation, an arm or a beam having a free end, a constant thickness or a variation of less than 40%, preferably less than 30%, more preferably less than 20% with respect to the average thickness, for example the mean of the thicknesses measured along the second tooth.

[0043] In one embodiment, each first tooth of the first escapement wheel has:

[0044] a first tooth root defining a first tooth root circle diameter DPPD1,

[0045] a first tooth thickness EPD1,

[0046] a first tooth tip defining a first tooth tip circle diameter DTPD1,

[0047] and, from the first tooth root to the first tooth tip, the first tooth thickness EPD1 varies by at least 40%, preferably at least 50%, more preferably at least 80% compared to the first tooth thickness EPDPr1 measured at the first pitch diameter DPrPD1, defined as follows:

[0048] DPrPD1 = (DPPD1 + DTPD1 ) / 2

[0049] In the above embodiment, each first tooth can have at least one involute portion.

[0050] In one embodiment, the second tooth root circle diameter DPDD1 is equal or substantially equal to the first tooth root circle diameter DPPD1. In another embodiment, the second tooth root circle diameter DPDD1 can be different from the first tooth root circle diameter DPPD1.

[0051] In one embodiment, the first tooth thickness EPDPr1 measured at the first tooth average diameter DPrPD1 is strictly greater than the second tooth thickness EDDPr1 measured at the second tooth average diameter DPrDD1, preferably 3.EDDPr1<EPDPr1, preferably 3.5.EDDPr1<EPDPr1.

[0052] In one embodiment, the second teeth of the first escapement wheel are arranged in pairs between the first teeth of the first escapement wheel, i.e. two adjacent second teeth are arranged between two consecutive first teeth.

[0053] In one embodiment, each second tooth of the first escapement wheel has an arc-shaped arm shape designed according to a radius of curvature of the second tooth.

[0054] In one embodiment, the radius of curvature of two adjacent second teeth of the first escapement wheel is opposite. That is to say, if one second tooth of the escapement wheel is curved in a clockwise direction, the adjacent second tooth is curved in an anti-clockwise direction.

[0055] In one embodiment, the two adjacent second teeth of the first escapement wheel are U-shaped or horseshoe-shaped. In one embodiment, the U-shaped or horseshoe-shaped design of the two adjacent second teeth is designed to receive a first tooth of the second escapement wheel.

[0056] In one embodiment, the two adjacent second teeth of the first escapement wheel are symmetrical with respect to a plane of symmetry comprising the first rotation axis of the first escapement wheel.

[0057] In one embodiment, the first escapement wheel comprises:

[0058] 10 to 14 second teeth, preferably 12 second teeth, and / or

[0059] 5 to 7 first teeth, preferably 6 first teeth.

[0060] In one embodiment, the addendum circle diameter DTPD1 of the first teeth is strictly greater than the addendum circle diameter DTDD1 of the second teeth.

[0061] In one embodiment, the addendum circle diameter DTPD1 of the first teeth of the first escapement wheel is equal or substantially equal to the addendum circle diameter DTPD2 of the second teeth of the second escapement wheel.

[0062] In one embodiment, the gear train of the first escapement wheel is identical to the gear train of the second escapement wheel. In one embodiment, the first escapement wheel is identical to the second escapement wheel.

[0063] In one embodiment, the direction of the end protrusion is tangential to a circle centered on the first rotation axis of the first escapement wheel and passing through the end protrusion, or forms a protrusion in said direction.

[0064] A second aspect of the present invention can relate to an escape wheel for an escapement of a timepiece, the escape wheel comprising:

[0065] receiving a driving force from a driving wheel of the timepiece,

[0066] transmitting an impact force to maintain oscillation of a timepiece oscillator,

[0067] cooperating with an escape fork of the escapement,

[0068] forming a first escape wheel of an escapement, the first escape wheel being rotatably mounted about a first rotation axis and cooperating with another escape wheel forming a second escape wheel of the escapement, the second escape wheel rotating about a second rotation axis and comprising a gear train,

[0069] the escape wheel comprising a gear train, the gear train comprising:

[0070] first teeth configured to cooperate with at least the escape fork;

[0071] second teeth configured to cooperate with the gear train of the second escape wheel,

[0072] characterized in that each second tooth has an arm shape comprising at least one end protrusion configured to cooperate with the gear train of the second escape wheel.

[0073] A third aspect of the present invention can relate to an escape wheel for an escapement of a timepiece, the escape wheel being configured to:

[0074] receive a driving force from a driving wheel of the timepiece,

[0075] transmit an impact force to maintain oscillation of a timepiece oscillator,

[0076] cooperate with an escape fork of the escapement,

[0077] form a first escape wheel of an escapement, the first escape wheel being rotatably mounted about a first rotation axis and cooperating with another escape wheel forming a second escape wheel of the escapement, the second escape wheel comprising a gear train,

[0078] the escape wheel comprising a gear train, the gear train comprising:

[0079] first teeth configured to cooperate with at least the escape fork;

[0080] second teeth configured to cooperate with the gear train of the first teeth and / or the second escape wheel,

[0081] characterized in that each second tooth has the shape of an arm curved along a radius of curvature, the radius of curvature of two adjacent second teeth being opposite. That is to say, for a pair of teeth consisting of two adjacent second teeth, the first second tooth is curved in a first direction of rotation or first tangential direction and the second second tooth is curved in a second direction of rotation or second tangential direction (respectively opposite to the first direction of rotation or first tangential direction).

[0082] In one embodiment, the two adjacent second teeth are U-shaped or horseshoe-shaped.

[0083] In one embodiment, the gear train of the second escapement wheel comprises first teeth and second teeth,

[0084] and, when a second tooth of the second escapement wheel cooperates with a first tooth of the gear train of the first escapement wheel, the inner side of the second tooth of the second escapement wheel opposes the first tooth of the gear train of the first escapement wheel,

[0085] and the radius of curvature of the inner side of the second tooth of the second escapement wheel is smaller than the radius of curvature of the first tooth of the gear train of the first escapement wheel. Typically, when a second tooth of one escapement wheel cooperates with a first tooth of the gear train of another escapement wheel, the inner side of the second tooth of the escapement wheel opposes the first tooth of the gear train of the other escapement wheel,

[0086] and the radius of curvature of the inner side of the second tooth of the escapement wheel is smaller than the radius of curvature of the first tooth of the gear train of the other escapement wheel.

[0087] In one embodiment, the gear train of the second escapement wheel comprises first teeth and second teeth,

[0088] and, when a second tooth of the second escapement wheel cooperates with a first tooth of the gear train of the first escapement wheel, the inner side of the second tooth of the second escapement wheel opposes the first tooth of the gear train of the first escapement wheel,

[0089] and the inner side of the second tooth of the second escapement wheel has a center of curvature disposed on the same side of the inner side as the center of curvature of the first tooth of the gear train of the first escapement wheel. Typically, when a second tooth of one escapement wheel cooperates with a first tooth of the gear train of another escapement wheel, the inner side of the second tooth of the escapement wheel opposes the first tooth of the gear train of the other escapement wheel,

[0090] and the inner side of the second tooth of the escapement wheel has a center of curvature disposed on the same side of the inner side as the center of curvature of the first tooth of the gear train of the other escapement wheel.

[0091] In one embodiment, the inner side of the second tooth of the second escape wheel is concave and the first tooth of the gear train of the first escape wheel is convex. Typically, the inner side of the second tooth of each escape wheel is concave to mate with the convex first tooth of the other escape wheel.

[0092] A fourth aspect of the application can relate to a timepiece comprising an escapement according to the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0093] Other characteristics and advantages of the application will appear even more clearly on reading the following detailed description of an embodiment thereof, given as a non-restrictive example and illustrated by the appended drawings.

[0094] Figure 1 is a general view of an escapement comprising a first escape wheel, a second escape wheel and an escape lever;

[0095] Figure 2a is Figure 1 is a front view of the first escape wheel shown in

[0096] Figure 2b is Figure 2a is a detailed view of the first escape wheel shown in

[0097] Figure 3a is Figure 1 is a front view of the second escape wheel shown in

[0098] Figure 3b is Figure 3a is a detailed view of the second escape wheel shown in

[0099] Figure 4 is Figure 2a and Figure 2b is a side view of the first escape wheel shown in Figure 3a and Figure 3b is a side view of the second escape wheel shown in

[0100] Figure 5 shows Figure 2a and Figure 2b shows the first engagement phase of the first escape wheel shown in Figure 3a and Figure 3b shows the second engagement phase of the first escape wheel shown in

[0101] Figure 6 shows Figure 2a and Figure 2b shows the second engagement phase of the first escape wheel shown in Figure 3a and Figure 3b shows the second engagement phase of the first escape wheel shown in

[0102] Figure 7 shows Figure 2a andFigure 2b the first escape wheel and Figure 3a and Figure 3b the third engagement phase of the second escape wheel;

[0103] Figure 8 Alternative solutions of the gear train of the first escape wheel and / or of the second escape wheel are shown. DETAILED DESCRIPTION

[0104] Figure 1 A general view of an escapement 10, which is used in cooperation with a balance 51 of an oscillator 5 (not shown, but the balance plate 511 thereof is shown), is shown, the escapement 10 comprising, inter alia:

[0105] a first escape wheel 1,

[0106] a second escape wheel 2,

[0107] an escape lever 4.

[0108] As Figure 1 is shown:

[0109] The first escape wheel 1 can rotate about a first rotation axis Al and comprises a first pinion 13 and a first escape wheel 12, the first pinion being arranged to mesh with a driving wheel of the timepiece, the first escape wheel being generally drivable on the first rotation axis,

[0110] The second escape wheel 2 can rotate about a second rotation axis A2 and comprises a second escape wheel 22, the second escape wheel being generally drivable on the second rotation axis,

[0111] The escape lever 4 can rotate about a fourth rotation axis A4 and comprises first and second impact means 42a, 42b,

[0112] The balance plate 511 is rotatably mounted about a fifth rotation axis A5 and comprises a pin 511a, generally designed to cooperate with the first and second impact means 42a, 42b of the escape lever 4.

[0113] During operation, the first escape wheel 12 and the second escape wheel 22 alternately come into contact with the pivot escape lever 4, the first and second impact means 42a, 42b cooperating with the pin 511a of the balance plate 511 to deliver an impact force or to allow the release of the balance 51. Advantageously, the gear train of the first escape wheel 12 and the gear train of the second escape wheel 22 are identical. In particular, the first escape wheel 12 and the second escape wheel 22 are identical, except that the second escape wheel 22 is mounted upside down with respect to the first escape wheel 12. Furthermore, the first escape wheel 1 comprises a pinion 13 coaxial with the first escape wheel 12 and meshing with the teeth of a driving wheel (not shown).

[0114] As Figure 2a shown, the first escapement wheel 12 comprises a gear train comprising:

[0115] The first teeth 121, as will be described below, are arranged to cooperate at least with the pallets 4;

[0116] The second teeth 111, as will be described below, cooperate with the gear train of the second escapement wheel 22.

[0117] As Figure 3a shown, the second escapement wheel 22 comprises a gear train comprising:

[0118] The first teeth 221, as will be described below, are arranged to cooperate at least with the pallets 4;

[0119] The second teeth 211, as will be described below, cooperate with the gear train of the first escapement wheel 12.

[0120] The first teeth 121, 221 of the first 12 and second 22 escapement wheels are designed to cooperate by contact with the impact means 41a, 41b and the blocking means 43a, 43b of the pallets 4, respectively. Likewise, the first teeth 121, 221 of the first 12 and second 22 escapement wheels are also used to contact the second teeth 211, 111 of the second 22 and first 12 escapement wheels, respectively, which will be described in detail in Figures 5 to 7 .

[0121] Figure 2a and Figure 3a are general views of the first 12 and second 22 escapement wheels, respectively, Figure 2b and Figure 3b are detail views of the second teeth 111, 211 of the first 12 and second 22 escapement wheels, respectively.

[0122] Since the first 12 and second 22 escapement wheels are similar, only the Figure 2a and Figure 2b will be described in detail below.

[0123] Figure 2a The second teeth 111 are shown extending from a second tooth root diameter DPDD1 to a second tooth tip circle diameter DTDD1. The first teeth 121 extend from the second tooth root circle diameter DPDD1 to a first tooth tip circle diameter DTPD1. These first teeth 121 each comprise an escapement 121a, specifically an escapement surface 121a arranged at the first tooth tip circle diameter DTPD1. These means 121a form points 121a. It is precisely these points 121a that cooperate with the impact means 41a or the blocking means 43a of the pallets 4. Note that Figure 1The first escape wheel 12 is shown rotating anticlockwise and providing a tangential impulse to the blocking wheel 4 through the impulse device 41a at the point 121a.

[0124] Furthermore, the addendum diameter DTPD1 of the first teeth is strictly greater than the addendum diameter DTDD1 of the second teeth.

[0125] The first teeth 121 and the second teeth 111 are disposed on the same plane P. In particular, two second teeth 111 are disposed between two consecutive first teeth 121. When the first escape wheel 12 is in mesh with the second escape wheel 22, the space separating the two consecutive second teeth 111 defines a housing 113 in which a first tooth 221 of the second escape wheel 22 can be installed.

[0126] The thickness EDDPr1 of the second teeth 111 is strictly less than the thickness EPDPr1 of the first teeth 121, for example, on average second tooth diameter DPrDD1, the arc of which is equal to the arcs of the second dedendum diameter DPDD1 and the second addendum diameter DTDD1.

[0127] In particular 3. EDDPr1 < EPDPr1, even 3.5. EDDPr1 < EPDPr1.

[0128] On average second tooth diameter DPrDD1, the distance dl between the two second teeth 111, or in other words, on average second tooth diameter DPrDD1, the extent dl of the housing 113 is strictly greater than the thickness EPDPr1 of the first teeth 121. In particular, it can be 1.2. EPDPr1 < dl, even 1.3. EPDPr1 < dl.

[0129] Each of the second teeth 111 has an end protrusion 111a, for example in the form of a point, disposed on the level of the second tooth addendum diameter DTDD1, the purpose of which is to cooperate by contact with the first tooth 221 of the second escape wheel 22, in particular with the side portions 221b, 221c of the first tooth 221 of the second escape wheel 22.

[0130] In a particular embodiment, the end protrusions 111a are rounded surfaces, which are contiguous with the inner side portions 111c of the second teeth 111, which also constitute the walls of the housing 113. In particular, the end protrusions 111a extend from the second tooth addendum diameter DTDD1 to a second tooth intermediate diameter DTDD1', DTDD1' < DTDD1, in particular 1.05. DTDD1' < DTDD1, further 1.04. DTDD1' < DTDD1, further 1.02. DTDD1' < DTDD1.

[0131] Alternatively, in addition to the end protrusions 111a, the second teeth 111 have a first end portion 111b and a second end portion 111c, which are disposed on the level of the second tooth addendum diameter DTDD1. Figure 1In addition to the shapes illustrated, the end projections 111a can also take the form of a combination of at least one rectilinear surface and / or at least one curved surface, which can or can not be continuous. Alternatively, the end projections 111a can take the form of rectilinear surfaces only. Alternatively, the end projections 111a can take the form of edges.

[0132] The end projections 111a are located at the tip circle diameter DTDD1 of the second teeth. In the case where DTDD1' - DTDD1, or even DTDD1' = DTDD1, the end projections form part of the tip of the second teeth 111, or the tip of the second teeth 111.

[0133] Advantageously, the inner side 111c is not functional, only the end projections 111a are functional, which can drive the first teeth, and vice versa. In this way, the shape of the inner side 111c can maximize the size of the housing 113 and / or minimize the thickness EDDPr1 of the second teeth 111.

[0134] Thus, in one particular embodiment, the second teeth 111 are curved, so that it is advantageous for the inner side 111c to recede from the sides 221b, 221c of the first teeth 221 of the second escapement wheel 22 when the first and second escapement wheels 12, 22 are engaged. In particular, the second teeth 111 are concave as seen from the housing 113, unlike a conventional gear train, the projections of which are elliptical, the sides of which are convex as seen from the space between two consecutive second teeth Figure 2b or Figure 3b Preferably, the second teeth 111 are symmetrical with respect to a plane PI passing through the first pivot axis Al of the first escapement wheel 12.

[0135] Each second tooth 111 is also provided with a functional side 111b for driving a second tooth 211 of the second escapement wheel 22, in particular by contacting the functional side 211b of another second tooth 211. The functional sides 111b extend from the gear train root diameter of the second teeth DPrDD1 to the gear train tip diameter of the second teeth DTDD1.

[0136] The functional sides 111b are projections as seen from the space between the second teeth 111 and the first teeth 121, just like the sides of a conventional tooth. Said space defines a housing 114. The distance d2 between the second teeth 111 and the first teeth 121, or in other words the extent d2 of the housing 114 at the mean second tooth diameter DPrDD1, is strictly greater than the thickness EDDPr1 of the first teeth 121.

[0137] In particular 1.1. EDDPr1 < d2, even 1.2. EDDPr1 < d2.

[0138] Each first tooth 121 comprises functional sides 121b, 121c extending between the second tooth dedendum diameter DPDD1 and the second tooth addendum diameter DTDD1. In particular, seen from the space between the second tooth and the first tooth, these sides 121b, 121c are convex and symmetrical with respect to a plane P2 passing through the first pinion 12 first pivot axis Al, like in a traditional gear train. These sides are provided for the meshing function of the first and second escapement pinions 12, 22. The part of the first tooth 121 between the second tooth addendum diameter DTDD1 and the first tooth addendum diameter DTPD1, ending with the tooth tip 121a, is provided only for the escapement function.

[0139] In the particular non-limiting example shown, the second escapement pinion 22 has the same characteristics as the first escapement pinion 12. As Figure 3a and Figure 3b The reference of the first escapement pinion 12 relative features starts with "2" instead of "1". The reference of the first escapement pinion 12 diameters or thicknesses or dimensions ends with "2" instead of "1".

[0140] Figure 4 A front view of the first escapement pinion 12 or of the second escapement pinion 22 is shown. Advantageously, said wheel has one and only one horizontal plane in the plane P, with a constant height hi. The thickness EDDPr1 of the second tooth 111 (and / or the thickness EDDPr2 of the second tooth 211) is less than the height hi, even much less than the height hi. In particular, 1.5. EDDPr1 < hi.

[0141] Figures 5 to 7 Different stages of the meshing of the first escapement pinion 12 with the second escapement pinion 22 are shown.

[0142] Figure 5 A front view of the first escapement pinion 12 is shown, rotated counterclockwise around its first rotation axis Al, and bringing the second escapement pinion 22 clockwise around its second rotation axis A2. The meshing described above is first achieved by the first tooth 121 of the first escapement pinion 12, the side 121b of the first tooth being in contact with the protrusion 211a of the second tooth 211 of the second escapement pinion 22. The contact between the first tooth 121 and the second tooth 211 is achieved only by the side 121b of the first tooth 121 and the protrusion 211a of the second tooth 211.

[0143] Figure 6 A front view of the first escapement pinion 12 is shown, rotated counterclockwise around its first rotation axis Al, and bringing the second escapement pinion 22 clockwise around its second rotation axis A2. The meshing described above is first achieved by the first tooth 121 of the first escapement pinion 12, the side 121b of the first tooth being in contact with the protrusion 211a of the second tooth 211 of the second escapement pinion 22. The contact between the first tooth 121 and the second tooth 211 is achieved only by the side 121b of the first tooth 121 and the protrusion 211a of the second tooth 211. Figure 5In the following sequence, the second tooth 111 of the first escape wheel 12 comes into contact with the second tooth 211 of the second escape wheel 22. Specifically, the side 111b of the second tooth 111 of the first escape wheel 12 drives the side 211b of the second tooth 211 of the second escape wheel 22.

[0144] Figure 7 An alternative is shown for the second tooth 111, in which Figure 6 In the following sequence, the second tooth 111 of the first escape wheel 12 comes into contact with the second tooth 211 of the second escape wheel 22. Figure 6 In the following sequence, the second tooth 111 of the first escape wheel 12 comes into contact with the second tooth 211 of the second escape wheel 22.

[0145] These different sequences are repeated so that the second escape wheel 22 can be driven by the first escape wheel 12.

[0146] In a particular embodiment, the first escape wheel 12 and the second escape wheel 22 each comprise 6 first teeth 121, 221 and 6 pairs of second teeth 111, 211. Of course, these numbers can vary depending on the desired escapement pitch.

[0147] Figure 8 An alternative is shown for the second tooth 111, in which

[0148] Figure 8 On the left is a first alternative in which the inner side 111c of the second tooth 111 has a straight or flat portion instead of a curved portion, as shown in Figure 2b or Figure 3b ,

[0149] Figure 8 On the right is a second alternative in which the second tooth 111 has a pointed protrusion 111a protruding from the inner side 111c instead of a curved portion continuous with the inner side 111c, as shown in Figure 2b or Figure 3b .

[0150] Advantageously, the first escape wheel 12 and the second escape wheel 22 are designed as hollow as possible in order to minimize their inertia. Specifically, the first teeth 121, 221 are hollow. The hubs of the escape wheels 12, 22 are also hollow. The thickness EDDPr1 of the second teeth 111, 211 is small, which greatly helps to minimize the inertia of the first escape wheel 12 and the second escape wheel 22, while also allowing the desired number of first teeth to be installed depending on the operation of the escapement in which the escape wheels are involved.

[0151] The first escape wheel 12 and the second escape wheel 22 are preferably obtained by micro-machining techniques, such as laser cutting, in particular femtosecond laser, or deep reactive ion etching (DRIE), or LIGA.

[0152] The first escape wheel 12 and the second escape wheel 22 can be wholly or partially composed of single crystal silicon, regardless of orientation, polycrystalline silicon, amorphous silicon, amorphous silicon dioxide, doped silicon, regardless of type and degree of doping, or porous silicon. The first and second escape wheels can also be composed of silicon carbide, glass, ceramic, quartz, ruby, or sapphire. Alternatively, the first and second escape wheels can be manufactured from a metal or metal alloy, in particular a metal alloy that is at least partially amorphous. For example, the wheels can be composed of nickel or a nickel phosphorus alloy NiP. The first escape wheel 12 and the second escape wheel 22 can be made of different materials.

[0153] Industrial applications

[0154] The escapement according to the application can be used for industrial applications.

[0155] It will be appreciated that various modifications and improvements can be made to the embodiments of the application described herein which will be obvious to those skilled in the art without departing from the scope of the application.

[0156] In particular, the first escape wheel 12 and the second escape wheel 22 can differ from each other in terms of the size of the hub or the interface with the shaft and the material.

[0157] At least one of the above-described escape wheels can also be used in any other type of escapement, such as a natural or direct impulse escapement.

[0158] The second teeth can not be two by two symmetrical and / or can not have a constant or almost constant thickness over their entire height.

Claims

1. An escapement (10) for a timepiece, said escapement being arranged to receive a driving force from a driving wheel of the timepiece and to deliver an impulse force to maintain an oscillation of an oscillator (5) of the timepiece, said escapement comprising: a first escapement wheel (12) rotatably mounted about a first axis of rotation (Al) and comprising a train of wheels equipped with first teeth (121) and second teeth (111), said first teeth being arranged to deliver at least the impulse force to maintain the oscillation of the oscillator (5), a second escapement wheel (22) rotatably mounted about a second axis of rotation (A2) and comprising a train of wheels arranged to deliver at least the impulse force to maintain the oscillation of the oscillator (5) and to cooperate with the second teeth (111) of the first escapement wheel (12), characterized in that each second tooth (111) of the first escapement wheel (12) has an arm shape comprising at least one end protrusion (111a) arranged to cooperate with the train of wheels of the second escapement wheel (22).

2. The escapement (10) of claim 1, wherein the train of wheels of the second escapement wheel (22) comprises first teeth (221) arranged to deliver at least the impulse force to maintain the oscillation of the oscillator (5) and second teeth (211) arranged to cooperate with the train of wheels of the first escapement wheel (12), wherein each second tooth (211) of the second escapement wheel (22) has an arm shape comprising at least one end protrusion (211a) arranged to cooperate with the train of wheels of the first escapement wheel (12).

3. The escapement (10) according to claim 2, wherein: the second teeth (111) of the first escapement wheel (12) are arranged to cooperate with the first teeth (221) of the second escapement wheel (22), the cooperation between the second teeth (111) of the first escapement wheel (12) and the first teeth (221) of the second escapement wheel (22) being achieved only by the end protrusions (111a) of the second teeth (111) of the first escapement wheel (12), and / or the second teeth (211) of the second escapement wheel (22) are arranged to cooperate with the first teeth (121) of the first escapement wheel (12), the cooperation between the second teeth (211) of the second escapement wheel (22) and the first teeth (121) of the first escapement wheel (12) being achieved only by the end protrusions (211a) of the second teeth (211) of the second escapement wheel (22).

4. The escapement (10) according to claim 2 or 3, wherein: the end protrusions (111a) of each second tooth (111) of the first escapement wheel (12) are arranged to cooperate only with the first teeth (221) of the second escapement wheel (22), and / or the end protrusions (211a) of each second tooth (211) of the second escapement wheel (22) are arranged to cooperate only with the first teeth (121) of the first escapement wheel (12).

5. The escapement (10) according to any one of claims 1 to 4, comprising an escapement lever (4) arranged to: reversibly block the rotation of the first (12) and / or second (22) escape wheel, receive an impact force from the first (12) and / or second (22) escape wheel and transmit it to the oscillator (5) to maintain the oscillation of the oscillator (5).

6. An escapement (10): According to claim 5, wherein, the first teeth (121) of the first escape wheel (12) have a tip (121a) that cooperates only with the escapement lever (4), According to claim 5 depending on any one of claims 2, 3 or 4, wherein the first teeth (221) of the second escape wheel (22) have a tip (221a) that cooperates only with the escapement lever (4).

7. The escapement (10) according to any one of claims 1 to 6, wherein each of the at least one end projection (111a) of the first escape wheel (12) has a first engagement portion arranged to be in contact with the gear train of the second escape wheel (22) when each second tooth (111) of the first escape wheel (12) cooperates with the gear train of the second escape wheel (22), wherein each first engagement portion is arranged between two circles having diameters DTDD1 and 0.94.DTDD1, preferably between two circles having diameters DTDD1 and 0.96.DTDD1, preferably between two circles having diameters DTDD1 and 0.98.DTDD1, DTDD1 being the addendum circle diameter of the second teeth (111) of the first escape wheel (12).

8. The escapement (10) according to claim 7, wherein each first engagement portion comprises: at least one circular surface, preferably convex and / or protruding, and / or at least one flat surface, and / or at least one edge.

9. The escapement (10) according to any one of claims 1 to 8, wherein, each second tooth (111) of the first escape wheel (12) has at least one second engagement portion arranged to be in contact with the gear train of the second escape wheel (22) when each second tooth (111) of the first escape wheel (12) cooperates with the gear train of the second escape wheel (22), wherein the second engagement portion is at least partially arranged between two circles having diameters DTDD1 and 0.50.DTDD1, preferably between two circles having diameters 0.95.DTDD1 and 0.60.DTDD1, preferably between two circles having diameters 0.90.DTDD1 and 0.70.DTDD1, DTDD1 being the addendum circle diameter of the second teeth (111) of the first escape wheel (12).

10. The escapement (10) according to claim 9, wherein each second tooth (111) of the first escape wheel (12) has a first side and an opposite second side, the at least one end projection (111a) being arranged on or at one side of the first side, the at least one second engagement portion being arranged on or at one side of the second side, each second engagement portion particularly comprising at least one convex contact surface.

11. The escapement (10) according to any one of claims 1 to 10, wherein The first tooth thickness EPDPr1 measured with the first tooth average diameter DPrPD1 is strictly greater than the second tooth thickness EDDPr1 measured with the second tooth average diameter DPrDD1, preferably 3 < EDDPr1 < EPDPr1, preferably 3.5 < EDDPr1 < EPDPr1.

12. The escapement (10) according to any one of claims 1 to 11, wherein, The second teeth (111) of the first escape wheel (12) are arranged in pairs between the first teeth (121) of the first escape wheel (12), In particular, wherein two adjacent second teeth (111) of the first escape wheel (12) are symmetrical with respect to a plane of symmetry comprising the first rotation axis (A1) of the first escape wheel (12).

13. The escapement (10) according to any one of claims 1 to 12, wherein, The addendum circle diameter DTPD1 of the first teeth is strictly greater than the addendum circle diameter DTDD1 of the second teeth.

14. The escapement (10) according to any one of claims 1 to 13, wherein, The gear train of the first escape wheel (12) is identical to the gear train of the second escape wheel (22).

15. A timepiece comprising at least one escapement (10) according to any one of claims 1 to 14.

Images