Timepiece mechanism comprising a ratchet cooperating with a mobile part

Abstract

The present invention relates to a clockwork mechanism comprising a moving part (1) arranged to be driven in rotation and a ratchet (2) comprising at least one pivotally mounted lever (3) equipped with a beak (31) that engages with the teeth (11) of the moving part (1) under the action of at least one corresponding elastic force (4), such that, in the operating position, rotation of the moving part (1) in at least one direction is not possible until the torque of the at least one elastic force (4) is exceeded. The mechanism further comprises locking means (6, 7) actuable for moving and retaining the lever (3) in an assembly position in which it does not prevent the mounting of the moving part (1). Rotation of the moving part in the operating position in the first direction releases the locking means (6, 7) and returns the lever (3) to its operating position.

Description

[0001] The present invention relates to a clockwork mechanism comprising a moving part and a ratchet arranged to cooperate with said moving part.

[0002] A ratchet is a lever with a beak that engages the teeth of a moving part under the action of a spring. The ratchet's function is generally to allow the moving part to move in only one direction or to block its rotation in a certain direction as long as the torque exerted by the spring is not exceeded.

[0003] Assembling a ratchet in its operating position relative to the movement it interacts with can be complicated. Generally, the spring must be activated with a tool to release the ratchet and its jaw, allowing the movement to be positioned. This necessitates the use of a tool to hold the ratchet away from the movement and / or requires the watchmaker to use one hand. Furthermore, activating the ratchet during assembly can lead to over-expansion and premature wear of the spring.

[0004] Certain watchmaking applications and mechanisms require a double ratchet, that is, a ratchet designed to lock the rotation of a moving part in both directions until a certain torque is exceeded. Such a double ratchet, in the prior art, generally consists of a lever ending in a beak designed to be held in the teeth of a moving part by a spring. With this design, the torque exerted by the lever on the moving part is not identical in both directions of rotation. Consequently, there is a risk of time drift, particularly in the direction where the torque is lower. Furthermore, with the double ratchet, the problem of assembly remains: to position the moving part, the lever must be actuated against the action of its spring to move it apart and allow the moving part to be placed on its axis.We can therefore understand the difficulty of the manipulation which consists of keeping the lever apart while positioning the mobile and also the risks of putting too much stress on the spring during this maneuver.

[0005] The object of the present invention is therefore to provide a clockwork mechanism comprising a moving part and a pawl, single or double arranged to cooperate with said moving part, which allows for easy mounting of the pawl relative to its moving part. Furthermore, in the case of a double pawl, an object of the present invention is to provide a pawl offering identical torque in both directions of rotation of the moving part with which it cooperates.

[0006] The present invention relates to a clockwork mechanism according to claim 1 and a clockwork part according to claim 9.

[0007] The attached figures schematically illustrate, by way of example, several forms of execution of a clockwork mechanism according to the invention. THE figures 1 à 3 illustrate a first form of execution of a clockwork mechanism according to the invention, the figure 1 illustrating the mechanism in its service position, the figure 2 illustrating the ratchet in its mounting position and the figure 3 illustrating the assembly of the mobile. The figures 4 à 9 illustrate a second embodiment of a clockwork mechanism according to the invention: The figure 4 is a view of the mechanism in its service position. figure 5 This is a view of the ratchet in its rest position before the star wheel is mounted. figure 6 Figure 7 is a view of the ratchet in the mounting position. Figure 7 is a view of the mechanism with the ratchet in the mounting position and the star in its operating position. figures 8a à 8c illustrate the movement of the ratchet from its mounting position to its operating position under the action of the star wheel. figures 9 à 11b illustrate a third embodiment of a mechanism according to the invention, the figure 9 illustrating the mechanism in its service position, the figure 10 illustrating the ratchet in its mounting position, the figure 11 the assembly of the mobile and figure 12 illustrating the beginning of the movement of the ratchet from its mounting position of the figure 11 to his service position of the figure 9 .

[0008] The present invention relates to a clockwork mechanism comprising a moving part and a ratchet designed to cooperate with said moving part. The moving part is arranged to be driven in rotation, while the ratchet comprises a lever subjected to the action of a spring and arranged to block the rotation of the moving part in at least one direction as long as the spring torque is not exceeded.

[0009] According to the classical definition, a ratchet is a lever with a beak that engages the teeth of a wheel under the action of a spring. Depending on the shape of the lever's beak, the ratchet can be unidirectional or bidirectional. In the following sections, embodiments in which the assembly according to the invention comprises a double ratchet will also be described, that is, two levers, each with its own elastic force or the same elastic force, acting on the same moving part. By extension, these examples of double ratchets will also be referred to as "ratchets." The classical definition of a ratchet is thus somewhat generalized to include at least one lever with a beak that engages the teeth of a wheel under the action of at least one corresponding elastic force.

[0010] In the first form of execution illustrated in figures 1 à 3 The clockwork mechanism comprises a star 1 and a pawl 2. The pawl 2 is unidirectional, that is, arranged to prevent the star 1 from rotating in a first direction, clockwise (according to the orientation of the figures). In this embodiment, the pawl 2 comprises a lever 3 carrying a beak 31 intended to engage with the teeth 11 of the star 1 in the operating position of the clockwork mechanism, and a spring 4 arranged to constrain said beak 31 into the teeth 11 in the operating position of the clockwork mechanism ( figure 1 The lever 3 is pivotally mounted at A on a moving part 5 of the clockwork mechanism coaxial with the star wheel 1, while the spring 4 is pivotally mounted at B on said moving part 5 by its heel 41. Thus, in this first embodiment, the spring 4 tends to rotate the lever 3 counterclockwise as shown in the figures. Furthermore, the lever 3 and the spring 4 are formed as a single piece to create a single-piece ratchet 2. Alternatively, the lever 3 and the spring 4 could be two separate parts.

[0011] There figure 1 illustrates the service position of the clockwork mechanism according to the first embodiment: the star 1 is pivoted on its axis coaxially with the moving part 5; the pawl 2 formed by the lever 3 and the spring 4 is positioned on the moving part 5 in its pivots A and B; the spring 4 forces the beak 31 of the lever 3 into the teeth 11 of the star 1. In this service position and given the shape of the beak 31, the star 1 can never rotate clockwise and can rotate counterclockwise when subjected to a torque sufficient to overcome the spring 4.

[0012] To assemble the clockwork mechanism, the pawl 2 must be mounted on the moving part 5, and then the pawl 2 must be moved and held in a position where its beak 31 is not in the path of the star 1, so that the star 1 can be fixed on its axis. Prior art generally uses specific tools to hold the pawl out of the way, but the present invention offers a simpler, tool-free solution.

[0013] According to the invention, the clockwork mechanism includes locking means arranged to lock the lever 3 in a mounting position which allows the mounting / dismounting of the star 1.

[0014] In the first illustrated embodiment, the locking means include a finger 6 formed at the end of an arm 32 of the lever 3 and arranged to cooperate with a shoulder 7 formed on the heel 41 of the spring 4. Thus, in this embodiment, the locking means are entirely part of the one-piece assembly that is the ratchet 2.

[0015] Once the ratchet 2, formed by the lever 3 and the spring 4, is placed on its pivots A, B on the moving part 5 (the ratchet 2 is then in a position similar to that of the figure 1 ), the watchmaker can rotate the heel 41 of the spring 4 against the action of said spring 4 (counterclockwise according to the figure 1 ). A first portion 71 of the shoulder 7 then comes into contact with the finger 6 and pivots the lever 3 against the action of the spring 4 into a so-called mounting position in which the beak 31 of the lever 3 is no longer in the path of the star 1 and no longer prevents the mounting of said star 1 onto the moving part 5. Then, by continuing the rotation of the heel 41, the finger 6 of the lever 3 falls into a second portion 72 of the shoulder 7 of the heel 41 of the spring 4. The locking means 6, 7 and the spring 4 are arranged so that the pawl 2 - lever 3 and spring 4 - remains locked in this mounting position under the action of this same spring 4, by a wedging phenomenon. The figure 2 illustrates this ratchet mounting position 2.

[0016] The ratchet 2 is moved into its mounting position entirely by hand using simple tweezers by operating the heel 41 and once locked in this mounting position, the ratchet 2 can be released and remains locked by its own spring 4 and the locking means 6, 7, without any other external intervention (neither tool nor hand).

[0017] With ratchet 2 in its mounting position ( figure 2 ), it is now possible to position star 1 in its service position ( figure 3 ) on its axis, coaxially with the moving part 5.

[0018] Once the star 1 has been driven onto its axis, the pawl 2 must be returned to its operating position for the proper functioning of the clockwork mechanism. To do this, from the position of the clockwork mechanism illustrated in the figure 3 - ratchet 2 in its mounting position and star 1 in its service position - simply actuate the star 1 in its direction of operation (counter-clockwise). The teeth 11 of the star 1 then actuate the lever 3 which pivots clockwise. In doing so, the heel 41 also pivots, pushed by the finger 6 against the shoulder 7 until said finger 6 releases the shoulder 7, causing the heel 41 to fall under the action of the spring 4. The lever 3 is then released and returns to its service position in the teeth 11 of the star 1 ( figure 1 ) pushed by spring 4. Thus, the parts of the clock mechanism find their final service position via the normal operation of the star.

[0019] In this first form of execution, we therefore obtain a clockwork mechanism comprising a moving part and a unidirectional ratchet acting on this moving part, the installation of which is very simple, without specific tools other than simple tweezers, the normal operation of the moving part ensuring the final positioning of the ratchet from its mounting position.

[0020] THE figures 4 à 8c illustrate a second embodiment of the present invention. Elements similar to those of the first embodiment shall be designated by the same reference number with a 0 added at the end.

[0021] In this second embodiment, the clockwork mechanism according to the invention comprises a star 10 and a pawl 20, but this time the pawl 20 is a double pawl, that is to say, arranged to prevent the star 10 from rotating in either direction until the torque exerted by the star 10 is sufficient to overcome the pawl 20. In this embodiment, the pawl 20 comprises two levers 30a, 30b, each carrying a beak 310a, 310b intended to engage with the teeth 110 of the star 10 in the operating position of the clockwork mechanism, constrained by a spring 40 ( figure 4 The levers 30a and 30b are pivotally mounted at points C and D, respectively, on a moving part 50 of the clockwork mechanism coaxial with the star wheel 10. As in the first embodiment, the pawl 20 in the second embodiment is also a single piece, with the levers 30a and 30b and the spring 40 being a single unit. Alternatively, the levers 30a and 30b and the spring 40 could be separate parts. Furthermore, each of the levers 30a and 30b could be subjected to its own distinct elastic force.

[0022] There figure 4 illustrates the service position of the clockwork mechanism according to the second form of embodiment: the star 10 is pivoted on its axis coaxially with the mobile 50; the pawl 20 formed by the levers 30a, 30b and the spring 40 is positioned on the mobile 50 in its pivots C and D; the spring 40 constrains each of the jaws 310a, 310b of the levers 30a, 30b in the teeth 110 of the star 10.

[0023] The pawl 20 is arranged so that when the star 10 is driven clockwise with a torque greater than that of the spring 40, it lifts the lever 30b, which in turn actuates the lever 30a. Once a tooth of the teeth 110 of the star 10 has passed the beak 310b of the lever 30b, the lever falls back between the next teeth under the action of its spring 40. Almost simultaneously or immediately afterward, the other lever 30a also returns to its position in the teeth 110 of the star 10. The same occurs when the star 10 is driven in the opposite direction. With the arrangement of the double pawl 20 and its mirrored levers connected by the same spring, an essentially identical torque is guaranteed in both directions of the star's rotation: the weaknesses of the spring and the levers are shared, and the torque is normalized.

[0024] To assemble the clockwork mechanism according to this second embodiment, it is necessary to be able to move and hold the pawl 20 in a position in which the star 10 can be fixed onto its axis. To achieve this, and as in the first embodiment, the clockwork mechanism according to the second embodiment includes locking means arranged to allow the movement and locking of each of the levers 30a, 30b in an assembly position in which the star 10 can be fixed in its service position.

[0025] In this second embodiment, the locking means include a shape 60 which is presented by one of the levers 30a and a corresponding counter-shape 70 carried by the other lever 30b.

[0026] Once the ratchet 20 formed by the levers 30a, 30b and the spring 40 is placed on its pivots C, D on the mobile 50 (position of the figure 5 ), the watchmaker can rotate one of the levers - the right lever 30b as illustrated - against the action of said spring 40 (counterclockwise according to the figure 4 ). Initially, a first portion 710 of the counterform 70 comes into contact with the form 60 and pivots the other left-hand lever 30a against the action of the spring 40. By continuing the rotation of the lever 30b, the form 6 of the other lever 30a falls into a second portion 720 of the counterform 70 so that the ratchet 2 remains locked in a so-called mounting position under the action of the spring 40 (locking). The figure 6 illustrates this mounting position of the ratchet 20. In this mounting position, the jaws 310a, 310b of the levers 30a, 30b no longer prevent the mounting of said star 10 on the mobile 50.

[0027] As in the first form of embodiment, the movement of the ratchet 20 into its mounting position is done entirely by hand using simple tweezers by operating one of the levers 30a, 30b and once locked in this mounting position, the ratchet 20 can be released and remains locked by its own spring 40 and the locking means 70, 80, without any other external intervention (neither tool nor hand).

[0028] With the ratchet 20 in its mounting position ( figure 5 ), it is now possible to position the star 10 in its service position ( figure 7 ) on its axis, coaxially with the moving part 50.

[0029] Once the star 10 has been driven onto its axis ( figure 7 ), it remains to replace the pawl 20 in its service position for the proper functioning of the clockwork mechanism. This step is illustrated sequentially in figures 8a à 8c To do this, from the position of the clockwork mechanism illustrated in the figure 7 - ratchet 20 in its mounting position and star 10 in its service position - simply turn star 10 in one direction (counter-clockwise on the figure 7 (more generally, the direction of operation of the lever that was not directly actuated for movement into the mounting position) so that lever 30a pivots to release the locking means 60, 70. figure 8a illustrates the beginning of the pivoting of lever 30a. Lever 30a pivots clockwise and form 60 is freed from counterform 70, which releases lever 30b which carries it ( figure 8b ). The two levers 30a, 30b can thus fall back into the teeth 110 of the star 11 in their service position under the action of the spring 40 ( figure 8c equivalent to the figure 4 ). Thus, the parts of the clockwork mechanism find their final service position via the normal operation of the star as in the first form of execution.

[0030] THE figures 9 à 11b illustrate a third embodiment of a clockwork mechanism according to the invention. In the two embodiments above, the star 1, 10 is a moving part with external teeth 11, 110, and the pawl 2, 20 therefore acts on the star 1, 10 from outside of it. The third embodiment illustrates the case where the moving part on which the pawl acts is a moving part with internal teeth, such as the crown 100 illustrated in figures 9 à 11b and its 1100 teeth. Apart from this difference, the third form of execution is in every respect similar to the previous form of execution and the 200 ratchet which cooperates with the 100 crown is also a double ratchet.

[0031] There figure 9 illustrates the ratchet 200 and the crown 100 in their service position, the jaws 3100a and 3100b of the levers 300a and 300b being constrained in the teeth 1100 of the crown 100 by their spring 400.

[0032] There figure 10 illustrates the 200 ratchet mounted on another moving part or on a fixed part of the watch mechanism and locked in its mounting position. As before, from the position of the figure 9 , it is sufficient to rotate one of the levers, in this case the left lever 30a, against the action of its spring until the locking means 600, 700 cooperate to rotate the other lever 300b and then to retain the two levers 300a, 300b in an assembly position in which said levers 300a, 300b and their beak 3100a, 3100b do not prevent the assembly of the latter.

[0033] There figure 11a This illustrates the crown 100, which has been mounted in its service position while the ratchet 200 is in its mounting position. To return the ratchet 200 to its service position in the teeth 1100 of the crown 100, simply rotate the crown 100 clockwise or counterclockwise: this can be seen on the figure 11b, the crown 100 actuates the lever 3100b which pivots and releases the locking means 600, 700. The two levers 300a, 300b then fall back into the teeth 1100 of the crown 100 under the action of the spring 400.

[0034] With this clockwork mechanism, we obtain the same advantages as with the second form of execution: a double ratchet that is easy to assemble and which guarantees an identical torque in both directions of rotation of the 1000 crown.

[0035] In the three examples above, we obtain a ratchet / moving wheel mechanism with an efficient ratchet and simplified moving wheel assembly: a common tool such as tweezers is sufficient to manipulate the ratchet into its mounting position, where it is held in place by the locking mechanism and / or its own elastic force without any other external intervention. Once the moving wheel is mounted, its normal operation releases the ratchet and places the clock mechanism in its working position. This simplifies assembly by eliminating complex tooling without adding cumbersome steps. Furthermore, the design also prevents excessive stress on the ratchet spring.

[0036] Examples of applications for a clockwork mechanism according to the invention are numerous and readily understandable to those skilled in the art, as the moving part can take any suitable form, including a star or a crown, as previously mentioned. Generally, the invention can be applied to all known uses of a ratchet: date disc, ratchet, date star, etc. It is also worth noting that it is easy to replace a prior art ratchet in an existing mechanism to obtain a clockwork mechanism according to the invention, with these advantages and, in particular, without modifying the moving part.

[0037] In the examples above, the ratchet, whether single or double, is a single piece. Alternatively, the ratchet could be made up of several parts joined together or arranged to work together.

[0038] Similarly, in some of the examples above, the pawl is itself mounted on a moving part of the clockwork mechanism. Alternatively, it could be mounted on a fixed part or on the frame of a clockwork movement.

[0039] The locking means described above are also an example given for illustrative purposes. It can be seen that in all three embodiments, the locking means are subjected to the action of the ratchet spring and are arranged to create a buttress between them following their movement against said spring. This buttress locks the ratchet lever(s) in an assembly position in which it / they do / do not impede the assembly of the clockwork mechanism's moving part. Any other suitable locking means could be considered (hook, jumper, etc.). Furthermore, the elastic force acting on the locking means could be separate from that acting on the ratchet lever, the latter being subjected, for example, to its own dedicated jumper.

[0040] Furthermore, in the examples above, the locking means are entirely integrated into the ratchet and are part of it. Alternatively, these locking means could be separate components or even distinct parts (finger, lever, etc.) arranged to cooperate with the lever, spring, or any other part of the ratchet.

[0041] In general, a clockwork mechanism according to the invention comprises a moving part arranged to be driven in rotation and a ratchet comprising at least one lever equipped with a beak which penetrates the teeth of the moving part under the action of an elastic force so that the rotation of the moving part in at least one first direction is not possible until the torque of the elastic force is exceeded.According to the invention, the clockwork mechanism further comprises locking means arranged so that the actuation of the locking means causes the lever to move against the action of the elastic force into a so-called mounting position in which its beak does not prevent the mounting of the mobile into its service position, the locking means being further arranged to retain the lever in this mounting position as long as the mobile is not pivoted in the first direction, the rotation of the mobile in the first direction while the lever is in its mounting position causing the release of said lever whose beak then falls into the teeth of the mobile under the action of the elastic force.

[0042] In the first embodiment, the locking means are partly carried by one end of the ratchet spring and it is by rotating this end that the lever is driven into its mounting position.

[0043] In the last two forms of embodiment, the ratchet comprises two levers, each carrying a part of the locking means, so that by actuating one of the levers against the action of the elastic force, both levers are moved into a mounting position.

[0044] Preferably, the ratchet is a single piece: the lever(s), their jaw, and the elastic force are all from one piece.

Claims

1. A clockwork mechanism comprising a moving part (1; 10; 100) arranged to be driven in rotation and a ratchet (2; 20; 200) comprising at least one lever (3; 30a, 30b; 300a, 300b) mounted to pivot and equipped with a beak (31; 310a, 310b; 3100a, 3100b) which engages in the teeth (11; 110; 1100) of the moving part (1; 10; 100) under the action of at least one corresponding elastic force (4; 40; 400) such that, in the operating position, rotation of the moving part (1; 10; 100) in at least one first direction is not possible until the torque of the at least one elastic force (4; 40; 400) is exceeded, characterized by the fact thatit further includes locking means (6, 7; 60, 70; 600, 700) arranged so that the actuation of the locking means (6, 7; 60, 70; 600, 700) causes the displacement of the lever or each lever (3; 30a, 30b; 300a, 300b) against the action of the corresponding elastic force (4; 40; 400) into a so-called mounting position in which the lever or each lever (3; 30a, 30b; 300a, 300b) does not prevent the mounting of the mobile (1; 10; 100) into its service position, the locking means (6, 7; 60, 70; 600, 700) being further arranged to retain the lever or each lever (3; 30a, 30b; 300a, 300b) in this mounting position as long as the mobile (1; 10; 100) in the service position is not pivoted in the first direction, and so that the rotation of the mobile (1; 10; 100) in the service position in the first direction while the or each lever (3; 30a, 30b;300a, 300b) is in its mounting position causes the locking means to be released, the lever or each lever and their beak (31; 310a, 310b; 3100a, 3100b) then falling into the teeth (11; 110; 1100) of the moving part (1; 10; 100) under the action of the corresponding elastic force (4; 40; 400).; 2. Mechanism according to claim 1, characterized by the fact that The elastic force is a spring (4) one end of which, called the heel (41), is mounted to pivot; and by the fact that the locking means are partly carried by the lever (3) and partly carried by the heel (41) of the spring (4), the pivoting of the heel (41) against the action of the spring (4) causing the pivoting of the lever (3) into its mounting position, the heel (41) retaining the lever (3) in this mounting position by the action of the spring (4) as long as the movable (1) in the service position does not pivot in the first direction.

3. Mechanism according to claim 1, characterized by the fact thatThe ratchet (20) comprises a first and a second lever (30a, 30b) constrained by the same elastic force (40) in the teeth (110) of the moving part (10) and arranged such that the first lever (30a) prevents the moving part (10) from rotating in a first direction as long as the rotational torque of said moving part (10) does not exceed the elastic force (40), while the second lever (30b) prevents the moving part (10) from rotating in a second direction as long as the rotational torque of said moving part (10) does not exceed the elastic force (40), the locking means (60, 70) being distributed between the first and second levers (30a, 30b) such that the rotation of the second lever (30b) against the action of the elastic force (40) causes its displacement and that of the first lever (30a) to their mounting position in which neither of the first and second levers (30a, 30b) does not prevent the assembly of the mobile (10) in its service position, locking position in which the levers (30a,30b) are retained by the locking means; and, by the fact that when the levers (30a, 30b) are held in their mounting position by the locking means (60, 70), a rotation in the first direction of the mobile (10) in its service position causes the first lever (30a) to pivot and release the locking means, the two levers (30a, 30b) then resuming their service position in the teeth (110) of the mobile (10).

4. Mechanism according to the preceding claim, characterized by the fact that the elastic force is a spring (40) arranged to act simultaneously on the first and second levers (30a, 30b), ensuring essentially identical torque in both directions of rotation of the mobile (10) in its service position.

5. Mechanism according to one of the preceding claims, characterized by the fact that the ratchet (2; 20; 200) is a single piece, the lever(s), their jaws and the elastic force being made from a single piece.

6. Mechanism according to one of the preceding claims, characterized by the fact that The locking means are carried in part by the lever and / or by elastic force.

7. Mechanism according to one of the preceding claims, characterized by the fact that The locking mechanisms can be operated directly by hand or with a simple tool such as tweezers.

8. Mechanism according to one of the preceding claims, characterized by the fact that The locking means and / or elastic force are sufficient on their own to retain the lever in its mounting position.

9. Timepiece comprising a clockwork mechanism according to one of the preceding claims.

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