CH715887A2 - Locking member for a watch movement. - Google Patents

Abstract

The invention relates to a locking member (10) of a toothed wheel (20), the locking member (10) being integrally formed and comprising: - a frame (101), - a first lever (102) comprising a first locking tooth (102d) of the toothed wheel (20), - a first elastic return portion (103) connecting the first lever (102) to the frame (101), the locking member (10) comprises at less: - a second rocker (102) comprising a second locking tooth (102d) of the toothed wheel (20), - a second elastic return portion (103) connecting the second rocker (102) to the frame (101), and in that the first latch (102) and said at least one second latch (102) are arranged to sequentially block the rotation of the toothed wheel (20).

Description

The present invention relates generally to a locking or clutch member for a watch movement, for example a watch movement of a watch.

[0002] Blocking devices such as those described in documents WO2011120180A1 or EP2037335A2 are known in the prior art, in which a blocking member is arranged to block a rotation of a toothed wheel in a first direction of rotation, and allow free rotation of the toothed wheel in a second direction of rotation. On the other hand, these systems have the particular drawback of allowing a large displacement of the toothed wheel between two stop positions of the latter. As a consequence, the toothed wheel has to move forward by a large angular value to go to a next stop position, and can move back by a large angular value if it does not succeed, which generates significant “dead times”. in the case where the locking member is part of a winding device for example.

[0003] An object of the present invention is to respond to the drawbacks of the documents of the prior art mentioned above and in particular, first of all, to provide a locking member and a locking device which limits downtime or does not require the toothed wheel (typically a ratchet or a toothed wheel) to be rotated by a large angular value between two stop positions.

[0004] For this, a first aspect of the invention relates to a blocking member of a toothed wheel of a watch movement, the toothed wheel preferably forming a ratchet, the locking member being formed integrally and comprising: <tb> - <SEP> a chassis, <tb> - <SEP> a first lever comprising a first locking tooth arranged to block a rotation of the toothed wheel in a first direction of rotation, and to leave free the rotation of the toothed wheel in a second direction of rotation, <tb> - <SEP> a first elastic return portion connecting the first lever to the frame and forming means for positioning the first lever on the frame, the blocking member comprises at least: <tb> - <SEP> a second rocker comprising a second locking tooth arranged to block the rotation of the toothed wheel according to the first direction of rotation, and leave free the rotation of the toothed wheel according to the second direction of rotation, <tb> - <SEP> a second elastic return portion connecting the second lever to the frame and forming means for positioning the second lever on the frame, are arranged to sequentially block the rotation of the toothed wheel in the first direction of rotation.

The locking member of the above implementation comprises a plurality of latches, each connected to the frame integrally or in one piece by a respective elastic return portion. Each elastic return portion also forms positioning means for positioning each respective rocker relative to the frame, so as to sequentially block the toothed wheel. In other words, each of the plurality of latch is offset (typically angularly) relative to the other latch to lock the toothed wheel at an intermediate position relative to the other latch. As a result, only one rocker blocks the toothed wheel at a time. This implementation makes it possible to limit a return stroke of the toothed wheel between two stop positions and the dead times. It is understood that such a unidirectional locking member here can form part of a clutch device and be just as well called a clutch member, and in particular a unidirectional clutch member.

Advantageously, the locking member comprises a plurality N of rockers each comprising a locking tooth arranged to block the rotation of the toothed wheel in the first direction of rotation, and to leave the rotation of the toothed wheel free, according to the second direction of rotation, and the toothed wheel has an angular pitch a, and two locking teeth of two adjacent rockers are separated by an angular distance δ defined by: δ = M. α + α / N, where M is an integer, the toothed wheel comprising a number of teeth Z, then preferably: M = Z / N.

According to the above implementation, the rockers are distributed evenly so that each block the toothed wheel sequentially with the smallest possible travel or backtracking, always the same. Thus, in a winding or clutch function, the “blind spots” or “dead times” or even backward travel are limited, so that engagement is almost immediate. There is therefore no need for a retaining member (typically a jumper) to hold the toothed wheel in place, which improves the design, the assembly or even the size, and as explained above, makes it possible to reduce strongly blind spots.

Advantageously, each elastic return portion, forming the positioning means of each respective latch, preferably leaves free (or preferably free) at least one degree of freedom of each respective latch, according to a rotation of an axis parallel to a axis of rotation of the toothed wheel. In other words, each rocker can pivot to let the toothed wheel pivot in the second direction of rotation. It should be understood that each elastic return portion preferentially allows the pivoting displacement, and has a much greater stiffness for the other degrees of freedom (a stiffness preferably 10 times or 100 times or 1000 times greater for the other degrees of freedom). In practice, only a rotational displacement is allowed, the other displacements are negligible.

[0009] Advantageously, each elastic return portion, forming the positioning means of each respective latch, defines a pivot axis of each respective latch. Each rocker, formed integrally with each respective elastic return portion and the frame, can pivot around an axis of rotation, defined by the elastic deformation of each elastic return portion.

[0010] Advantageously, each elastic return portion is arranged for: <tb> - <SEP> define a blocking position of each respective rocker, in which each rocker is arranged to block the rotation of the toothed wheel according to the first direction of rotation, <tb> - <SEP> allow each respective rocker to pivot towards an escape position in which each rocker is arranged to leave free the rotation of the toothed wheel in the second direction of rotation, <tb> - <SEP> exert an elastic return force on each respective rocker from the exhaust position to the blocking position.

[0011] Advantageously, each rocker comprises: <tb> - <SEP> a first arm supporting the locking tooth, <tb> - <SEP> a second arm supporting a stopper, arranged to come into mechanical stopper with the frame, when the locking tooth blocks the rotation of the toothed wheel in the first direction of rotation. In particular, the first arm and the second arm are oriented with respect to each other to follow the periphery of the toothed wheel, and schematically, each lever has a boomerang or “banana” shape. Furthermore, the stop allows the rocker (in the locked position) to rest on the frame, which secures or locks the stop positions of the toothed wheel. An additional safety function is provided, in comparison with a jumper for example.

[0012] Advantageously, each rocker is not a jumper. In other words, each rocker pivots about an axis of rotation, so that during a rotation of the rocker, a first side of the rocker moves towards the toothed wheel, while a second side of the rocker. rocker moves away from the toothed wheel. In contrast, a jumper moves in a single block with respect to a toothed wheel that it must position, without tilting on itself.

Advantageously, the locking tooth of each lever is arranged to block the rotation of the toothed wheel by touching (or contacting) only one tooth of the toothed wheel. In contrast, a jumper typically simultaneously contacts two adjacent teeth of the toothed wheel that it must position.

Advantageously, at least two latches, and preferably all the latches, are identical to each other. In other words, the rockers have similar shapes and / or dimensions and preferably identical (except for manufacturing tolerances).

[0015] Advantageously, the frame is arranged to surround the toothed wheel. In other words, the frame has a ring or closed loop shape, which allows: <tb> - <SEP> to distribute the rockers over the entire periphery of the toothed wheel, so as to optimize space and / or <tb> - <SEP> to provide good rigidity during the manufacturing and / or assembly phases, and / or <tb> - <SEP> to provide a fixing interface, arranged at the level of the ring or of the closed loop, at a distance from the rockers and elastic return portions.

Advantageously, the stop is separated by an angular distance from the locking tooth by an angular distance δ1 defined by: δ1 = M1. α + k, in which M1 is an integer and α / 3 <k <2α / 3 and ideally k = α / 2. This implementation makes it possible to facilitate the release of each latch, with limited bulk. In fact, when the toothed wheel is released or escaped, the stop can pivot towards a hollow in the toothing of the toothed wheel, without however interfering with the latter.

Advantageously, each elastic return portion of each lever comprises two flexible blades, each flexible blade has a width e and a thickness b respecting the following ratio: 2 <e / b <20, and preferably: e / b = 10. Such an implementation provides good elasticity and deformation, while remaining feasible.

[0018] Advantageously, the two flexible blades have a common portion so as to form a cross. In other words, the flexible blades have a junction, which makes it possible to precisely define the position of the (virtual) axis of rotation or of pivoting of the respective rocker.

Advantageously, the two flexible blades form a spider, two adjacent branches of which form an angle within a range of values ranging from 10 ° to 170 ° and preferably from 30 ° to 120 °.

[0020] Advantageously, each flexible blade has an angular stiffness k of between: 0.001 Nmm / ° <k <1 Nmm / °.

Advantageously, a first flexible blade connects the frame to the end of the first arm, and a second flexible blade connects the frame to the end of the second arm. This implementation makes it possible to maximize the lengths of the flexible blades.

Advantageously, the blocking member is formed from silicon. Such a silicon part has many advantages: its manufacture, typically by etching, allows complex shapes to be given, the friction coefficients are low, and the elastic resistance is high.

[0023] A second aspect of the invention relates to a locking device, comprising: <tb> <SEP> a locking member according to the first aspect of the invention, <tb> <SEP> a toothed wheel, preferably forming a ratchet.

[0024] Watch movement comprising at least one locking member according to the first aspect of the invention.

[0025] Watch comprising at least one locking member according to the first aspect of the invention.

Other characteristics and advantages of the present invention will emerge more clearly on reading the following detailed description of an embodiment of the invention given by way of non-limiting example and illustrated by the accompanying drawings, wherein : <tb> - <SEP> FIG. 1 represents a top view of a locking member according to the invention; <tb> - <SEP> FIG. 2 represents a perspective view of the locking member of FIG. 1; <tb> - <SEP> FIG. 3 represents a top view of a sub-assembly formed by the locking member of FIG. 1, with a toothed wheel; <tb> - <SEP> FIG. 4 represents a perspective view of the sub-assembly of FIG. 3; <tb> - <SEP> FIG. 5 represents a top view of the sub-assembly of FIG. 3, mounted on a ratchet wheel; <tb> - <SEP> FIG. 6 represents a perspective view of the sub-assembly mounted on a ratchet wheel of FIG. 5.

[0027] Figure 1 shows a top view of a locking member 10 according to the present invention, comprising three rockers 102, each connected to the same frame 101 by a portion of the respective elastic return portion 103, integrally. Indeed, the blocking member 10 is formed in one piece, which facilitates the assembly operations of a watch movement.

Advantageously, the blocking member 10 is formed in silicon, by a DRIE ("Deep Reaction Ion Etching") etching process, or even in Ni or NiP using a UV-LiGA lithography process (" Lithography, Galvanoformung, Abformung “). These methods make it possible to manufacture such a part of complex shape (the frame, the elastic return portions, the levers) in one piece, or in one piece with great precision.

In detail, each lever 102 comprises a first arm with a locking tooth 102d and a second arm with a stop 102b. Each elastic return portion comprises two flexible blades 103f1 and 103f2, which each have one end connected to the first or to the second arm, another end connected to the frame 101 and join together to form a spider 103c.

This architecture makes it possible to define a pivot type articulation between each lever 102 and the frame 101. In fact, each elastic return portion 103, via the spider 103c formed by its flexible blades 103f1 and 103f2, defines an axis of rotation (virtual and normal to the plane of FIG. 1) of each respective latch 102, at the level of the spider 103c.

As shown in Figure 2 in perspective, each flexible blade 103f1 and 103f2 of each elastic return portion 103 has a width e and a thickness b respecting the following ratio: 2 <e / b <20, and preferably: e / b = 10

Such an implementation provides good elasticity to each elastic return portion 103, as will be explained below. By way of example, each flexible strip 103f1, 103f2 has an angular stiffness k between: 0.001 Nmm / ° <k <1 Nmm / °

Furthermore, the locking member 10 comprises a smooth hole 104 to allow fixing and positioning on another part of the watch movement by a driven pin, and two grooved holes 105, to allow fixing by a driven pin / glued. We can of course consider other fixing methods (by screwing, elastic interlocking, etc.)

Finally, as shown in Figure 1, the elastic return portions 103 each position their respective rocker 102 relative to the frame 101 in a stable locking position, or rest position.

As shown in Figure 3, the locking member 10 is arranged to cooperate with a toothed wheel 20 of angular pitch α. In particular, the blocking member 10 is arranged to block a rotation of the toothed wheel 20 in a first direction of rotation (clockwise), and leave free the rotation of the toothed wheel 20 in a second direction of rotation (anti-clockwise). hourly). In the case shown, the toothed wheel 20 is a ratchet, but other embodiments of the shape of the teeth can be envisaged, for example a wolf tooth wheel.

Indeed, each locking tooth 102d of each lever 102 can block the clockwise rotation of the toothed wheel 20, and in Figure 3 where the latches 102 are numbered 102-1, 102-2, 102- 3 to distinguish them (but this numbering is arbitrary and is only used for FIG. 3), it is the locking tooth 102d-2 of the lever 102-2 which prevents a clockwise rotation of the toothed wheel 20.

Regarding the rocker 102-1, during the anti-clockwise rotation of the toothed wheel 20, the latter will "push" the locking tooth 102d-1 to rotate the rocker 102-1 in a clockwise direction , around a theoretical axis passing through the spider 103c-1, to go into an escape position. The elastic return portion 103-1 will exert a return force on the lever 102-1 to bring it back from the exhaust position to the blocking position.

Figure 3 also shows a particular arrangement of the latches 102-1, 102-2, 102-3. Indeed, the latter are angularly offset from each other by an angle δ defined according to: δ = M.α + α / N, in which M is an integer, N is the number of rockers and if the toothed wheel 20 comprises a number of teeth Z, then preferably: M = Z / N.

In the particular case of Figure 3, δ = 3.α + α / 3, which makes it possible to block the toothed wheel 20 every 1/3 of its pitch α. This limits backward movement (clockwise) of toothed wheel 20 during a reassembly or disengagement operation. In other words, each flip-flop 102-1, 102-2, 102-3 blocks the toothed wheel sequentially and shifted in time.

As regards the blocking position of each lever 102-1, 102-2, 102-3, each lever 102-1, 102-2, 102-3 comprises a stop 102b to secure and guarantee this position of blocking, for example during an impact which would generate too much force on the toothed wheel 20 in the clockwise direction. In the case of the lever 102-2 which blocks the toothed wheel 20 in FIG. 3, if a force exerted by the toothed wheel 20 causes a deformation of the elastic return portion 103-2, then the lever 102-2 would pivot in counterclockwise and the stop 102b-2 would come into abutment on the frame 101, so that the toothed wheel 20 could not rotate more clockwise.

Finally, Figure 3 shows the lever 102-3 whose arm which supports the stop is in contact or almost in contact with the toothed wheel 20, which guarantees that the locking tooth of this lever 102-3 will enter well in abutment against the toothed wheel 20 (in this position of the lever 102-3 imposed by the contact or almost contact between the stop arm and the toothed wheel 20, the portion of the top of the locking tooth 102d-3 is on diameter less than the outside diameter of the toothed wheel 20).

This function is guaranteed because the stop is separated by an angular distance from the locking tooth by an angular distance δ1 defined by: δ1 = M1. α + k, in which : M1 is an integer and α / 3 <k <2α / 3 and ideally k = α / 2. In the particular case of figure 3, δ1 = 2. α + α / 2

[0043] Figure 4 shows the sub-assembly of Figure 3 in perspective for greater clarity. In the case shown in figure 4, the toothed wheel 20 is blocked by the locking tooth 102d of the lever 102 located approximately at 11 o'clock, and if the toothed wheel 20 rotates in the anti-clockwise direction of α / 3, then it is the flip-flop 102 located at 6 o'clock which will engage with the toothed wheel to block any reversal in clockwise direction.

In the case of a winding mechanism, or of a clutch mechanism, the toothed wheel 20 can only move back here by an angle α / 3 at most, instead of an angle α s' there is only one flip-flop or if the three flip-flops are not offset. In the present case with three flip-flops 102 sequentially offset, the recoil amplitude is divided by three, which correspondingly reduces dead times or blind spots, compared to a holding member such as a jumper for example. It can also be seen that the locking member 10 has a frame 101 which surrounds the toothed wheel 20, which makes it possible to distribute the levers 102 over the entire periphery of the toothed wheel 20, so that three levers 102 can be provided. in a small footprint.

Figures 5 and 6 show from the front and in perspective the sub-assembly of Figures 3 and 4 cooperating with a ratchet wheel 30. It is possible to consider integrating this ratchet wheel 30 in a clutch or winding mechanism watch. Typically, the pawl holder wheel 30 is integral with the toothed wheel 20, and the locking member is itself integral with a bridge or a plate of the watch, so that it is possible to block the rotation of the door wheel. pawl 30 in the clockwise direction, with little backward movement of the pawl holder wheel 30 between two stop positions (at most 1/3 of the angular pitch of the toothed wheel 20), so that downtime is reduced.

It will be understood that various modifications and / or improvements obvious to a person skilled in the art can be made to the various embodiments of the invention described in the present description without departing from the scope of the invention defined by the appended claims. In particular, reference is made to three latches, but the blocking member can comprise two, four or more latches. In addition, the elastic return portion is formed mainly by two flexible blades, but one can consider a single flexible blade, or a torsion bar for example.

Claims (16)

1. Locking member (10) of a toothed wheel (20) of a watch movement, the toothed wheel (20) preferably forming a ratchet, the locking member (10) being formed integrally and comprising: - a frame (101), - a first lever (102) comprising a first locking tooth (102d) arranged to block a rotation of the toothed wheel (20) in a first direction of rotation, and to leave free the rotation of the toothed wheel (20) in a second direction of rotation, - a first elastic return portion (103) connecting the first lever (102) to the frame (101) and forming means for positioning the first lever (102) on the frame (101), characterized in that: the locking member (10) comprises at least: - a second rocker (102) comprising a second locking tooth (102d) arranged to block the rotation of the toothed wheel (20) according to the first direction of rotation, and leave free the rotation of the toothed wheel (20) according to the second direction of rotation, - a second elastic return portion (103) connecting the second lever (102) to the frame (101) and forming means for positioning the second lever (102) on the frame (101), and in that the first latch (102) and said at least one second latch (102) are arranged to sequentially block the rotation of the toothed wheel (20) in the first direction of rotation. 2. Locking member (10) according to the preceding claim, comprising a plurality N of rockers (102) each comprising a locking tooth (102d) arranged to block the rotation of the toothed wheel (20) in the first direction of rotation, and leave free the rotation of the toothed wheel (20), in the second direction of rotation, in which the toothed wheel (20) has an angular pitch a, and in which two locking teeth (102d) of two adjacent rockers (102) are separated by an angular distance δ defined by: δ = M. α + α / N, where M is an integer, the toothed wheel (20) comprising a number of teeth Z, then preferably: M = Z / N. 3. Locking member (10) according to one of the preceding claims, wherein each elastic return portion (103), forming the positioning means of each respective rocker (102), leaves free at least one degree of freedom of each. respective rocker (102), according to a rotation of an axis parallel to an axis of rotation of the toothed wheel (20). 4. Locking member (10) according to the preceding claim, wherein each elastic return portion (103), forming the positioning means of each respective rocker (102), defines a pivot axis of each respective rocker (102). 5. Locking member (10) according to one of the preceding claims, wherein each elastic return portion (103) is arranged for: - define a blocking position of each respective rocker (102), in which each rocker (102) is arranged to block the rotation of the toothed wheel (20) according to the first direction of rotation, - Allow each rocker (102) to pivot towards an escape position in which each rocker (102) is arranged to leave free the rotation of the toothed wheel (20) in the second direction of rotation, - exerting an elastic return force on each respective rocker (102) from the exhaust position to the locking position. 6. Locking member (10) according to one of the preceding claims, wherein each latch (102) comprises: - a first arm supporting the locking tooth (102d), - A second arm supporting a stop (102b), arranged to come into mechanical stop with the frame (101), when the locking tooth (102d) blocks the rotation of the toothed wheel (20) in the first direction of rotation. 7. Locking member (10) according to the preceding claim, in its dependence on claim 2, wherein the stop (102b) is separated by an angular distance from the locking tooth (102d) by an angular distance δ1 defined. by : δ1 = M1.α + k, in which : M1 is an integer and α / 3 <k <2α / 3 and ideally k = α / 2. 8. Locking member (10) according to one of the preceding claims, wherein each elastic return portion (103) of each lever (102) comprises two flexible blades (102f1, 102f2), each flexible blade (102f1, 102f2) has a width e and a thickness b respecting the following ratio: 2 <e / b <20, and preferably: e / b = 10 9. Locking member (10) according to the preceding claim, wherein the two flexible blades (102f1, 102f2) have a common portion so as to form a cross (103c). 10. Locking member (10) according to the preceding claim, wherein the two flexible blades (102f1, 102f2) form a spider (103c) whose two adjacent branches form an angle within a range of values ranging from 30 ° to 120 ° . 11. Locking member (10) according to one of claims 8 to 10, wherein each flexible blade (102f1, 102f2) has an angular stiffness k of between: 0.001 Nmm / ° <k <1 Nmm / ° 12. Locking member (10) according to one of claims 8 to 11, in their dependence on claim 6, wherein a first flexible blade (102f1, 102f2) connects the frame (101) to the end of the first arm , and a second flexible blade (102f1, 102f2) connects the frame (101) to the end of the second arm. 13. Locking member (10) according to one of the preceding claims, formed of silicon. 14. Locking device, comprising: a locking member (10) according to one of the preceding claims, a toothed wheel (20), preferably forming a ratchet. 15. Watch movement comprising at least one locking member (10) according to one of claims 1 to 13. 16. Watch comprising at least one locking member (10) according to one of claims 1 to 13.