CH717288B1 - Stop pawl for watch movement. - Google Patents

Abstract

The present invention relates to a pawl (1) for stopping a watch movement (2), comprising a body provided at the periphery with a latching lug intended to cooperate with the teeth (50) of a ratchet (5). ); a hub intended to cooperate freely in rotation by assembly with an axis (7) fixed according to an angular movement between an active position in meshing of said lug with the teeth (50) of said ratchet (5) and an inactive position, via intermediate positions; characterized in that at least said hub comprises an opening, said body being configured to be assembled or disassembled with the axle (7) thanks to the opening of said hub. The invention also relates to a watch movement (2) with such a pawl (1), as well as a timepiece including such a movement (2).

Description

Field of the invention

[0001] The invention relates to a stop pawl for a watch movement.

[0002] The invention also relates to a watch movement comprising at least one such stop pawl.

[0003] The invention also relates to a timepiece comprising at least one such clock movement.

[0004] The invention relates to the field of watchmaking, and more particularly to the field of stop pawls for controlling the transmission of a movement, a chime, or even another functionality of a timepiece.

Background of the invention

[0005] In the classic architecture of a watch movement, a detent comprises a ratchet driven in an angular movement by a barrel. This ratchet in the form of a toothed wheel cooperates with a stop pawl. This stop pawl is mounted to rotate and is provided on the periphery with a lug. This lug cooperates in meshing with the teeth of the ratchet, so as to only allow said ratchet to rotate in one direction. Indeed, the mobility of the pawl ensures its rotation according to an angular movement from an active position, in meshing of said lug with the teeth of said ratchet towards an inactive position, in which the lug is retracted and the ratchet can rotate freely. The return from the inactive position to the active position as well as maintaining the pawl in mesh with the ratchet are carried out via a return means. In short, the return means returns the pawl to the active position to block the rotary movement of the ratchet. Thus the movement of said pawl ensures a certain return angle which prevents the balance from beating again, also preventing the barrel from emptying.

The return means is in the form of an independent spring, such as a bent wire or an elastic blade, one end of which is fixed in the blank, while the opposite end is attached to the pawl.

[0007] In addition to the addition of an independent part, the return effected by a spring makes the assembly and disassembly of such a watch movement complex. Indeed, during assembly, it is necessary to place the spring by constraining it, in particular by fixing one of its ends on the blank and the opposite end on the pawl, while correctly positioning said pawl in meshing with the teeth of the ratchet already in place.

[0008] As such, the pawl is mounted on a blank within a housing. This assembly is carried out via an axis ensuring the fixing of said pawl on the blank. The axis cooperates internally with a closed hub, of circular shape, provided within the pawl, so as to create a pivot connection, allowing the free rotation of the pawl relative to the axis. Such an axis is in the form of a screw, screwed into a complementary thread provided within said housing. This type of assembly therefore allows the pawl to be dismantled by unscrewing the axle, before emptying the barrel, said pawl still being able to be constrained by the tension of the spring but especially by the tension of the barrel, which is strongly discouraged to avoid any damage. of a component, or even a sudden expulsion of the pawl.

Summary of the invention

[0009] The invention aims to simplify a watch movement, by reducing the number of components and by simplifying assembly and disassembly operations.

[0010] For this purpose, the invention envisages a stop pawl specifically shaped with an open hub in order to allow its assembly by a sliding operation under the fixing axis secured within the blank.

[0011] Preferably, the stop pawl integrates the return means necessary to keep it in mesh with the ratchet, so as to form a snap fit.

[0012] To do this, the invention relates to a stop pawl for a watch movement, comprising a body provided with at least: – on the periphery, a latching lug with the teeth of a ratchet; – a hub intended to cooperate freely in rotation by assembly with a fixed axis according to an angular movement between an active position in meshing of said lug with the teeth of said ratchet and an inactive position, via intermediate positions; characterized in that at least: said hub comprises an opening, said body being configured to be assembled or disassembled with the axle thanks to the opening of said hub.

[0013] According to additional, non-limiting characteristics, said body may generally have a U shape.

[0014] Said opening may comprise side walls spaced at a distance configured to ensure the maintenance of the body around the axis.

[0015] Said hub may comprise a bottom shaped like an arc of a circle; said bottom being extended by side walls converging from the outside towards the inside of said body.

[0016] Said pawl may comprise means for locking said bottom by clipping with the axis.

[0017] Said pawl may comprise means for returning said stop pawl during its angular movement, from the inactive position to the active position, said return means and said body being in one piece.

[0018] Said return means may comprise at least one elastic blade with one end secured to said body and a free opposite end.

[0019] Said body may include, projecting at the periphery and located opposite the opposite end, a hooking means abutting said opposite end.

[0020] Said body may comprise a groove extending between an interior face of said elastic blade and said body from the integral end of said body and to the free end of said elastic blade; - the free end of said elastic blade comprising a projecting offset on the inner face.

[0021] Said groove may comprise opposite the offset, a recess for receiving said offset.

Said body is made of a metallic material.

Said body is composed of a nickel-phosphorus alloy.

Said body is manufactured by a LIGA type process.

[0025] Such a configuration of the pawl integrating the reminder makes it possible to reduce its bulk, with simplified manufacturing of such a timepiece.

[0026] Furthermore, the design of the ratchet, in particular of the return, makes it possible to separate such parts when they are packaged in bulk, preventing them from hanging together in clusters.

[0027] The invention also envisages a specific mounting of such a pawl in relation to the blank making it possible to simplify this operation, eliminating the need for tensioning of an independent spring. The ratchet being free to rotate, the positioning of the ratchet in meshing is considerably simplified.

The ratchet can be mounted before said ratchet, and vice versa for disassembly. In particular, when the ratchet has a generally U shape with an open hub, said ratchet can be slid under the axis before positioning the ratchet. It is only the subsequent positioning of the ratchet that keeps the ratchet in place. Therefore, once the ratchet is mounted, the pawl can no longer come out, which provides security for dismantling the watch movement. In fact, it is then necessary to remove the ratchet first and first empty the barrel. Therefore, such an assembly further simplifies the configuration, by eliminating an axis in the form of fixing screws and the precise step of tapping the blank.

[0029] For this purpose, the invention also relates to a watch movement comprising – a supporting structure in the form of a blank; – a ratchet mounted on said blank in a rotary movement, said ratchet being provided with teeth; – a latching mechanism with the teeth of said ratchet, said latching mechanism being rotatably mounted inside a housing provided within said blank; – an axis of free rotation of said latching mechanism within the housing of said blank, said axis cooperating in fixing with a bore formed within the housing of said blank; characterized in that – said latching mechanism comprises a pawl stop according to the invention.

[0030] According to additional, non-limiting characteristics, the axis may comprise a head, ensuring superior retention of the ratchet along said axis.

[0031] Said bore can be tapped; said axis is in the form of a screw.

Said axis can be in the form of a nail driven into said bore.

Said housing comprises an internal wall cooperating with an exterior face of the elastic blade of said ratchet.

[0034] Therefore, the particular configuration of a pawl integrating the return means and its mounting within the watch movement make it possible to control the return action at a range of its angular movement. Indeed, according to a first range, the ratchet is free to rotate and although the lug is in mesh with the teeth, it does not apply any force to the ratchet, reducing the wear of the teeth over time. It is only on a second range of its angular movement that the return comes into action when said return means is compressed. Along this travel including these two ranges, the friction between the pawl and the ratchet is therefore drastically reduced.

[0035] Furthermore, depending on the shape of the housing in the blank, it is possible to vary the ranges of the angular movement of said pawl, to control the action of its return to bring the pawl back to the position as soon as possible. locking of said ratchet. This early return makes it possible in particular to limit emptying of the barrel during automatic winding.

[0036] Furthermore, such a clock movement does not require the attachment of an independent spring, in particular a precise tapping step in the blank.

The invention also relates to a timepiece equipped with such a clockwork movement, such as a watch.

Brief description of the figures

[0038] The invention will be described below in more detail using the appended drawings, given by way of non-limiting examples, in which: [Fig. 1] schematically represents an elevational view of a first embodiment of a pawl, showing in particular an open hub; [Fig. 2] schematically represents an elevational view of a variant of the first embodiment of the pawl, showing in particular a return means integrated into the body of said pawl; [Fig. 3] schematically represents an elevational view of a second embodiment, showing in particular an open circular hub provided with a means of locking by clipping with the axis; [Fig. 4] schematically represents an elevational view of a third embodiment, showing in particular a return means integrated into the body with a means for hooking the end of the elastic blade; [Fig. 5] schematically represents an elevational view of a first configuration of a watch movement, equipped with the variant of the first embodiment of the pawl, in an active position in mesh with the teeth of a ratchet, showing in particular a closed housing; [Fig. 6] schematically represents a view similar to Figure 5, at the end of a first range of free rotation of said pawl and at the start of a second range of compression of the return means against an interior wall of the housing of the blank ; [Fig. 7] schematically represents a view similar to Figure 6, at the end of the second range of travel, in an inactive position of said pawl and at the end of compression of the return means against the interior wall; [Fig. 8] schematically represents an elevational view of a second configuration of a watch movement, equipped with the second embodiment of the pawl, in an active position in mesh with the teeth of a ratchet, showing in particular an open housing; [Fig. 9] schematically represents a perspective view of an example of a step of mounting the ratchet according to the variant of the first embodiment; and [Fig 10] schematically represents a view in a vertical section of a configuration of a watch movement equipped with the variant of the first embodiment of the pawl, showing in particular the fixing axis of said pawl with the blank.

Detailed description of the invention

[0039] The present invention relates to the field of watchmaking, and more particularly to the field of stop pawls 1 for controlling the transmission of a watch movement 2, a strike, or even a another feature of a timepiece.

[0040] First of all, the invention concerns a stop pawl 1, hereinafter referred to as a “pawl”, for a watch movement 2.

[0041] Such a pawl 1 comprises a body 3. This body 3 forms the entire part of the pawl 1. The body 3 of the pawl 1 therefore forms a single timepiece. The body 3 generally has a flattened shape. In revolution around a center of rotation, the body 3 comprises a polygonal perimeter with preferably rounded peripheral edges. The peripheral edges extend orthogonally or essentially orthogonally with respect to the upper and lower faces provided parallel to each other.

The body 3 of said pawl 1 is provided with at least several elements. These elements are therefore constituted by one or more parts of said body 3.

First of all, the body 3 comprises at the periphery, a lug 4. This lug 4 extends in a projecting manner relative to the periphery, namely that the lug 4 protrudes outwards. The lug 4 extends radially or essentially radially, its median axis passing through the center of rotation of the body 3.

[0044] The lug 4 serves as a latch with the teeth 50 of a ratchet 5. Therefore, the lug 4 is shaped and dimensioned complementary to said teeth 50, so as to cooperate in at least partial meshing with the latter , as notably visible in Figures 5 and 6.

Furthermore, the body 3 comprises a hub 6. This hub 6 is intended to cooperate freely in rotation with a fixed axis 7. The hub 6 is centered or essentially centered on the center of rotation of the body 3. The hub 6 is provided in the form of a through hole from one towards the other of the upper and lower faces of said body 3.

Advantageously, said hub 6 is open. In other words, the hub 6 comprises an opening 60. Such an opening 60 extends in a communicating manner between the center and the exterior of the body 3.

According to one embodiment, said body generally has a U shape. Body 3 then generally has a horseshoe shape.

Preferably, said opening 60 comprises side walls 62 spaced at a distance configured to ensure the maintenance of the body 3 around the axis 7. In addition, the opening 60 of the hub 6 is dimensioned to allow the passage of the axis 7, to the nearest clearance in order to authorize the rotation of one relative to the other, once said axis 7 is correctly positioned at the center of said hub 6.

According to one embodiment, said hub 6 comprises a bottom 61 shaped in an arc of a circle. Said bottom 61 is extended by the side walls 62 converging from the outside towards the inside of said body 3. In short, the side walls 62 of the opening 60 approach each other moving towards the center , to ensure guidance of the body 3 relative to the axis 7 at the time of assembly. In addition, the side walls 62 are inclined at a slight slope. Such a configuration of the side walls 62 is particularly visible in Figures 1, 2 and 4.

According to one embodiment, the pawl 1 comprises a means 63 for locking said bottom 61 with the axis 7. Such locking means 64 keeps the body 3 assembled with the axis 7, while allowing free rotation said hub 6 around said axis 7.

[0051] Said locking means 63 can be an attached and independent part, such as an elastic ring type ring. Preferably, said locking means 63 is carried out by clipping with said axis 7. In particular, each side wall of the opening 60 comprises a boss 64, located near said bottom 61 and extending projecting towards the inside of the opening 60. In addition, said bosses 64 are spaced at a distance less than the diameter of said axis 7. Therefore, locking is carried out by means of an elastic deformation of the body 3 at the time of its assembly with the axis 7, when said bosses 64 come into contact with said axis 7. Such a locking means by clipping is particularly visible in Figure 3.

Furthermore, the hub 6 has an internal wall orthogonal to said upper and lower faces. This internal wall has a circular portion, corresponding to the periphery of a circle centered on the axis of rotation of said body 3. Such an open hub 6 is particularly visible in Figures 1 to 4.

[0053] Furthermore, the axis 7 is an attached part, forming part of the watch movement 2. The axis 7 ensures the fixing and maintenance of the body 3 relative to a support, such as a blank 8 which can preferably be a barrel bridge. The inner face of the hub 6 then comes into contact with the outer face of the axle 7, forming a pivot connection. Such contact can be direct and provided for sliding in rotation, or indirect via a rotating ring fitted to said axis 7.

The rotation of the hub 6 takes place according to an angular movement between an active position in meshing of said lug 4 with the teeth 50 of said ratchet 5 and an inactive position, via intermediate positions. In particular, in the active position, the mechanical assembly of the lug 4 with the teeth 50 blocks the rotary movement of the ratchet 5, while in the inactive position, the lug 4 is retracted, leaving the rotary movement of the ratchet 5 free. .

[0055] Under the action of the ratchet 5, the lug 4 rotates the pawl 1 from the active position according to a first angular portion of movement, maintaining at least partial meshing with the teeth 50, until reaching an inactive position , in which the lug 4 is no longer in contact with the teeth 50, then releasing the ratchet 5. The return of the pawl 1 into meshing with the ratchet 5 is carried out by a suitable movement, according to an inverse movement, so as to to only authorize the rotary movement of the ratchet 5 along one or more of the teeth of its teeth 50.

To do this, according to one embodiment, said stop pawl 1 may comprise a means 9 for returning said pawl 1 during its angular movement, from the inactive position to the active position.

Advantageously, said return means 9 and said body 3 are in one piece. It is therefore the pawl 1 which integrates this return means 9, freeing itself from an external and independent part. The reminder means 9 is therefore integrated.

[0058] As mentioned previously, such a configuration of the pawl 1 integrating the return means 9 makes it possible to reduce its bulk, with simplified manufacturing of such a timepiece.

[0059] According to a preferred embodiment, said return means 9 comprises at least one blade 90 with an end 91 secured to said body 3 and a free opposite end 92. Such a blade 90 extends substantially following the periphery of the body 3. The blade 90 extends equidistant or substantially equidistant from the periphery of said body 3, or else flaring from the end 91 towards the end 92 opposed. The blade 90 therefore forms an extension of the body 3 from its end 91. In addition, the space between the interior face of said blade 90 and the rest of the body 3 forms a groove 10. This groove 10 is closed at the level of the end 91 of junction of the blade 90 with said body 3.

Such a blade 90 is designed to be elastic, namely that it has a reversible deformation around a position of inertia. In short, the blade 90 returns to its original shape and position if it is constrained. This resilience of the blade 90 gives elasticity to the return means 9 and its spring effect.

The blade 90 has a rounded or arcuate shape. This curved shape improves the flexibility and the elastic character of said blade 90. As such, the elastic character of said blade 90 essentially conferred by the material constituting the body 3 of the pawl 1, of which the blade 90 is an integral part.

[0062] According to one embodiment, said body is composed of a metallic material. Preferably, said body of the pawl 1 is composed of a nickel-phosphorus alloy (NI-P).

The pawl 1 can be obtained by any type of process. Preferably, the body is manufactured by a LIGA type process (for “Rontgenlithographie, Galvanoformung, Abformung”, namely “X-ray lithography, electroforming, impression taking”), this name taking up the major successive stages of such a process ).

[0064] In particular, the overhang between the end 91 of junction with the body 3 and the opposite end 92, as well as the material constituting the body 3 and said said blade 90, ensure an elastic return of the blade 90 towards its inertia position, when said blade 90 is compressed and pushed towards the body 3, but also when the blade 90 is possibly pulled externally. In particular, under stress, the blade 90 undergoes a folding stress essentially along a first portion located from its end 91 of junction with the body 3. The opposite end 92 moves in an arc from the position of inertia by approaching said body 3. Said position of inertia is particularly visible in Figures 2 and 4.

[0065] According to one embodiment, said body 3 comprises, projecting at the periphery and located opposite the opposite end 92 of said blade 90, a hooking means 11 abutting said opposite end 92. Such a hooking means 11 can be in the form of a step, oriented towards said opposite end 92 and covering it externally. The hooking means 11 makes it possible in particular to prevent traction of the blade externally relative to the body 3, ensuring its locking to prevent outward deformation, only allowing flexibility of the blade 90 oriented towards the body 3 Such a hooking means 11 is particularly visible in Figure 4.

Preferably, the blade 90 can be constrained when it is positioned in locking of its opposite end 92 by the hooking means 11. In short, the blade 90 is already partially compressed. In addition, said hooking means 11 closes the groove 10, preventing the hooking in a cluster of several pawls 1 when these parts are packaged in bulk.

As mentioned previously, the groove 10 which extends between an interior face of said blade 90 and said body 3 from the end 91 secured to said body 3 and to the free opposite end 92 of said blade 90. In addition, the free opposite end 92 of said blade 90 comprises an offset 12 projecting on the interior face. Such an offset 12 is therefore in the form of a boss. The offset 12 has a thickness at least equal to the width of the groove 10. Therefore, said groove 10 comprises opposite the offset 12, a notch 13 for receiving said offset 12. Such a notch 13 forms a hollow in the body 3, in the form of a recess formed within the wall of the groove 10. The notch 13 is dimensioned, particularly in depth, to ensure the introduction of at least the distal part of the offset 12 during of a stress applied to said blade 90. Such an offset 12 and its notch 13 are particularly visible in Figure 2.

[0068] Like the hooking means 11, such a design of the pawl 1 equipped with such a notch receiving at least part of the offset, makes it possible to close the end of the groove 10, preventing the hooking in clusters of several ratchets 1 when these parts are packaged in bulk.

From the above, the body 3 of the pawl 1 integrating the return means 9 in the form of a blade 90, makes it possible to apply an elastic return force, when a constraint is applied along the distal part of said blade 90. Such a restoring force makes it possible to oppose the rotation of the hub 6 in one direction, when the body 3 is fixed around the axis 7, then returning the lug 4 in the opposite direction. An example of the forces applied is notably visible in Figures 6 and 7, showing a pawl 1 cooperating with a ratchet 5 within a watch movement 2.

[0070] As such, the invention also relates to such a clock movement 2.

[0071] Said watch movement 2 comprises a supporting structure in the form of a blank 8. Such a blank 8 serves as a support for various timepieces. The blank 8 is intended to be fixed on the exterior of a timepiece, such as the watch case. The blank 8 can be in the form of a plate. According to a preferred mode, the blank 8 can be the barrel bridge, or even a part integral with the barrel bridge.

[0072] The watch movement 2 also includes a ratchet 5. This ratchet 5 is provided with teeth 50. The ratchet 5 is mounted on said blank 8 in a rotary movement. In particular, such a rotary movement is induced by the barrel through a suitable connection.

[0073] The watch movement 2 also comprises a detent mechanism with the teeth 50 of said ratchet 5. Such a detent mechanism makes it possible to control the transmission of the rotary movement of said ratchet 5. In particular, the detent ensures transformation from, at the input, a continuous rotary movement induced by the ratchet 5, to, at the output, an oscillating reciprocating movement of said ratchet 5.

[0074] To do this, said latching mechanism is rotatably mounted inside a housing 14 provided within said blank 8. Such a housing 14 is dimensioned to allow the latching mechanism to be introduced into it. and to hold it there in order to cooperate with the teeth of the ratchet 5.

[0075] As such, the watch movement 2 comprises an axis 7 of free rotation of said detent mechanism within the housing 14 of said blank 8. The axis 7 is then dimensioned complementary to the hub 6 of the pawl 1. In addition, the axis 7 cooperates in fixing with a bore 15 provided within said housing 14.

[0076] Advantageously, said detent mechanism comprises a stop pawl 1 as previously described. The latching mechanism may include other timepieces, but preferably it only includes the pawl 1.

[0077] In particular, according to the embodiment where the pawl 1 does not integrate the return means 9, said clockwork movement 2 may comprise an independent return means 9, in the form of a spring, attached to the blank and on said pawl 1.

[0078] As mentioned previously, when the pawl 1 integrates the return means 9, said pawl 1 is then positioned in the housing 14, orienting the lug 4 towards the teeth 50 of the ratchet 5, while the blade 90 is located on the side opposite to said teeth 50. In addition, the housing 14 is open on the side intended for the cooperation of the pawl 1 with the ratchet 5. Such positioning is particularly visible in Figures 5 to 8.

[0079] Further, the clockwork movement 2 allows the blade 90 of the pawl 1 to be compressed, during its rotation induced by the rotary movement of said ratchet 5. This compression can be carried out by any type of means, in particular by a stop.

[0080] According to one embodiment, said housing 14 comprises an internal wall 140 cooperating with an exterior face of the blade 90 of said pawl 1. Thus, the housing 14 is formed hollow with a flat upper face 141 hollowed out in the thickness of the blank 8. From then on, the internal wall 140 extends orthogonally or substantially orthogonally from said upper wall 141 to the surface 80 of the blank 8.

[0081] According to one embodiment, the internal wall 140 can be continuous. In short, the internal wall 140 extends without interruption or without opening from one end of the housing 14 towards the other. The internal wall 140 then ensures the compression of the blade 90 at the level of its free end 92 during of the rotation of the pawl 1. Such a configuration is particularly visible in Figures 5 to 7.

[0082] According to another embodiment, said internal wall 140 of said housing 14 is discontinuous along part of its length located opposite said blade 90. In short, the housing 14 has a through opening its internal wall 140, on the side of the blade 90 of the pawl 1. This discontinuity of the internal wall 140 makes it possible to considerably lighten the blank 8. The discontinuity also makes it possible to control the movement of the pawl 1, in particular by dimensioning the length of the lower part of the internal wall 140, the upper angle of which serves as a stop for the compression of the blade 90 during the rotation of the pawl 1. Such a configuration is particularly visible in Figure 8.

[0083] As mentioned previously, the axis 7 allows the pawl 1 to be positioned and held in the housing 14, allowing its free rotation. To do this, the axis 7 cooperates in the lower part with the bore 15. In the upper part, the axis 7 comprises a head 70, ensuring the upper retention of the pawl 1 along said axis 7.

[0084] Furthermore, the axis 7 has an external diameter equivalent or substantially equivalent to the internal diameter of said hub 6, within clearance allowing the insertion of one relative to the other during assembly, and vice versa during assembly. disassembly, whether the contact between the periphery of the axis 7 and the hub 6 is direct or indirect via a rotating annular ring.

[0085] According to one embodiment, said bore 15 is tapped and axis 7 is then in the form of a screw. The tapping of the bore 15 is then carried out in addition to the thread of the axis 7. The assembly of the axis 7 in the form of a screw with the tapped bore 15 ensures removable fixing, easily allowing assembly and dismantling of the ratchet 1, by screwing and unscrewing said axis 7, before or after the assembly or disassembly of the ratchet 5.

[0086] Furthermore, such an assembly by screwing is adapted to a ratchet 1 provided with an open hub 6. In this case of an open hub 6 giving a U shape to said pawl 1, the assembly can be carried out once the axis 7 is screwed, by sliding said pawl 1. This assembly involves placing the pawl 1 first, to rotate it to the desired angular position and only then to place the ratchet 5. Such an assembly operation is particularly visible in Figure 9. Conversely during disassembly, it is possible to remove the ratchet 1 by unscrewing the axis 7 or preferably without unscrewing it. In the latter case, disassembly involves first extracting the ratchet 5, thus ensuring the prior emptying of the barrel.

[0087] According to another embodiment, the axis 7 is in the form of a nail driven into said bore 15. The assembly of the axis 7 in the form of a nail driven into the bore 15 is definitive , namely that once the nail is inserted, it can only be removed with difficulty, without risking damage to the other timepieces. Therefore, in order to authorize the dismantling of the pawl 1, its hub 6 is necessarily open, giving said pawl 1 its specific horseshoe shape. Therefore, the first assembly consisting of introducing the axis 7 into the bore 15 can be carried out after positioning the pawl 1, the introduction of the axis 7 taking place by passing through its hub 6. Preferably, for any assembly , once the axis 7 is introduced into the bore 15, the assembly of the pawl 1 is carried out by sliding. This assembly involves first placing the pawl 1, rotating it to the desired angular position and only then placing the ratchet 5. Such an assembly operation is particularly visible in Figure 9. Conversely during disassembly, it It is only possible to remove the pawl 1 by first removing the ratchet 5, then ensuring the prior emptying of the barrel.

[0088] Furthermore, an axis 7 in the form of a driven nail eliminates the precise step of tapping the bore 15, as well as the wear over time occurring during assembly and disassembly. This solution considerably simplifies assembly and disassembly, limiting the risk of damage to timepieces.

[0089] Further, the configuration according to a variant of the invention of a pawl 1 integrating the return means 9 in the form of the blade 90, makes it possible to facilitate the assembly and disassembly of said pawl 1 within the movement 2 d watchmaking. Indeed, this configuration makes it possible to limit the return action to a range of the angular movement of the pawl 1. According to a first range, the pawl 1 is free to rotate and although the lug 4 is in mesh with the teeth 50 of the ratchet, said lug 4 does not apply any force to the ratchet 5. In addition, along said first range, the friction between the lug 4 and the teeth 50 is almost non-existent, reducing wear over time. This first range corresponds to the angular travel of the pawl 1 from an active position in engagement of the lug 4 with the teeth 50, until the start of the stressing of the blade 90. The extent of said first range is in particular visible in Figures 5 and 6 between two angular positions of said pawl 1. It is only on a second range of the angular movement of the pawl 1 that the return comes into action when the blade 90 begins to be compressed until the The lug 4 arrives in the inactive position and loses engagement with the teeth 50. At this moment, the compression of the blade 90 returns the pawl 1 in the opposite direction to its initial position. The extent of said second range is notably visible in Figures 6 and 7 between two angular positions of said pawl 1.

[0090] Thus, along this movement including these two first and second ranges, the friction between the pawl 4 and the ratchet 5 is therefore drastically reduced.

[0091] Furthermore, depending on the shape of the housing 14 in the blank 8, as well as the dimensioning of the opening of the discontinuous internal wall 140, it is possible to vary the ranges of the angular movement of said pawl 1, with a view to controlling the action of its return to return pawl 1 as soon as possible to the locking position of said ratchet 5. This early return makes it possible in particular to limit the emptying of the barrel during automatic winding.

[0092] Furthermore, the fact that a first range of its movement ensures total freedom of movement for the ratchet 1, especially during assembly, the angular positioning of the ratchet 5 relative to the lug 4 is considerably simplified.

[0093] The invention also relates to a timepiece comprising the timepiece movement 2 as previously described. Such a timepiece may preferably be a watch.

Claims (19)

1. Stop pawl (1) for watch movement (2), comprising a body (3) provided with at least: – on the periphery, a latching lug (4) intended to cooperate with the teeth (50) of a ratchet (5); – a hub (6) intended to cooperate freely in rotation by assembly with an axis (7) fixed according to an angular movement between an active position in meshing of said lug (4) with the teeth (50) of said ratchet (5) and a position inactive, via intermediate positions; characterized in that at least: – said hub (6) comprises an opening (60), said body (3) being configured to be assembled or disassembled with the axle (7) thanks to the opening (60) of said hub (6). 2. Stop pawl (1) according to the preceding claim, characterized in that – said body (3) generally has a U shape. 3. Stop pawl (1) according to any one of the preceding claims, characterized in that – said opening (60) comprises side walls (62) spaced at a distance configured to ensure the maintenance of the body (3) around the axis (7). 4. Stop pawl (1) according to any one of the preceding claims, characterized in that – said opening (60) comprises a bottom (61) shaped in an arc of a circle; – said bottom (61) being extended by side walls (62) converging from the outside towards the inside of said body (3). 5. Pawl (1) according to the preceding claim, characterized in that it comprises – a means (63) for locking said bottom (61) by clipping with the axis (7). 6. Stop pawl (1) according to any one of the preceding claims, characterized in that it comprises – means (9) for returning said stop pawl (1) during its angular movement, from the inactive position to the active position; and in that – said return means (9) and said body (3) are in one piece. 7. Pawl (1) according to the preceding claim, characterized in that – said return means (9) comprises at least one elastic blade (90) with one end (91) secured to said body (3) and one free opposite end (92). 8. Pawl (1) according to the preceding claim, characterized in that said body (3) comprises – projecting from the periphery of said body (3) and located opposite the opposite end (92), a hooking means (11) abutting said opposite end (92). 9. Pawl (1) according to any one of claims 7 and 8, characterized in that said body (3) comprises – a groove (10) extending between an interior face of said elastic blade (90) and said body (3) from the end (91) secured to said body (3) and up to the free end (92) of said elastic blade (90); – the free end (92) of said elastic blade (90) comprising an offset (12) projecting on the inner face to close the end of the groove (10). 10. Pawl (1) according to the preceding claim, characterized in that – said groove (10) comprises opposite the offset (12), a recess (13) for receiving said offset (12) to ensure the introduction of at least one distal part of the offset (12). 11. Stop pawl (1) according to any one of the preceding claims, characterized in that – said body (3) is made of a metallic material. 12. Stop pawl (1) according to any one of the preceding claims, characterized in that – said body (3) is composed of a nickel-phosphorus alloy. 13. Stop pawl (1) according to any one of the preceding claims, characterized in that – said body (3) is manufactured by a LIGA type process. 14. Clockwork movement (2), comprising – a supporting structure in the form of a blank (8); – a ratchet (5) rotatably mounted on said blank (8), said ratchet (5) being provided with teeth (50); – a latching mechanism with the teeth (50) of said ratchet (5), said latching mechanism being rotatably mounted inside a housing (14) provided within said blank (8); – an axis (7) of free rotation of said latching mechanism within the housing (14) of said blank (8), said axis (7) cooperating in fixing with a bore (15) provided within the housing (14) of said blank (8); characterized by that – said detent mechanism comprises a stop pawl (1) according to any one of claims 1 to 13. 15. Clockwork movement (2) according to the preceding claim, characterized in that – in the upper part, the axis (7) comprises a head (70), ensuring the upper retention of the pawl (1) along said axis (7). 16. Clockwork movement (2) according to any one of claims 14 and 15, characterized in that – said bore (15) is tapped; – said axis (7) is in the form of a screw. 17. Clockwork movement (2) according to any one of claims 14 and 15, characterized in that – said axis (7) is in the form of a nail driven into said bore (15). 18. Clockwork movement (2) according to any one of claims 14 to 17, characterized in that – said housing (14) comprises an internal wall (140) cooperating with an exterior face of the elastic blade (90) of said pawl (1). 19. Timepiece comprising a timepiece movement (2) according to any one of claims 14 to 18.