Patent Grant
10890877
This application claims priority of European patent application No. EP17155912.3 filed Feb. 13, 2017, the content of which is hereby incorporated by reference herein in its entirety.
The invention relates to a pawl system for a wheel of a drivetrain for winding a horology barrel. The invention also relates to a horology movement comprising such a system. The invention also relates to a timepiece comprising such a system or such a movement. The invention finally relates to a method for configuring such a movement or such a timepiece. The invention additionally relates to a method of assembling such a movement or such a timepiece. The invention further relates to a method for dismantling such a movement or such a timepiece.
Mainsprings in manually wound or automatically wound timepieces are usually kept under tension by a pawl which is designed to collaborate with a ratchet mounted squarely on the barrel arbor. More particularly, the pawl immobilizes the ratchet in the direction of unwinding of the mainspring, and disengages when the manual or automatic winding device is actuated.
Automatic winding devices are also configured in such a way as to immobilize the ratchet in the direction of unwinding of the spring so that the ratchet pawl can be removed in timepieces provided with such devices. However, there is still the problem of dismantling the automatic movement, which exposes the watchmaker to the problem of uncontrolled untimely uncoiling of the mainspring of the barrel. For this reason, known timepieces with automatic winding of the prior art also comprise a device, notably a ratchet pawl, designed to immobilize the barrel arbor. While such a solution notably allows the timepiece to be operated independently of its automatic winding module, it is nevertheless suboptimal regarding the effectiveness of the automatic winding. This is because, in such cases, the oscillating mass has to overcome the resistive torque induced by the pawl, notably the pawl spring, in order to allow automatic winding of the mainspring. Such a construction may therefore be problematical when the winding power of the oscillating mass is limited because of the dimensions of the timepiece, particularly in the case of a small-diameter and/or small-thickness automatic movement.
Patent CH542468 discloses a one-piece ratchet pawl provided with a rigid first part and with an elastic second part. The rigid part comprises a clicking tooth designed to collaborate with the toothset of the ratchet so as to immobilize the ratchet in the direction of unwinding of the mainspring, and so as to disengage from the toothset of the ratchet in the direction of coiling of the mainspring. To this end, the elastic part of the pawl takes the form of an elastic arm, which becomes set as the clicking tooth disengages from the toothset of the ratchet in order to return the clicking tooth to a position of immobilizing the toothset of the ratchet. Where such a device is incorporated into a timepiece with an automatic winding mechanism, the oscillating mass has to overcome the resistive torque induced by the pawl, notably by the elastic part of the pawl.
There are alternatives to ratchet pawls. The ratchet pawl may for example be replaced by one or more pawls arranged in one or other of the manual or automatic winding trains. The work “La montre suisse à remontage automatique [Swiss watches with automatic winding]” discloses for example, on pages 170 to 174, a unidirectional automatic winding movement having no ratchet pawl, known by the reference “Zenith No. 133”. In this construction, pawls incorporated into the automatic winding module indirectly immobilize the ratchet in the direction of unwinding of the mainspring. Such a timepiece cannot therefore operate independently of its automatic winding module.
There are also alternatives to pawls. Patent application WO2015193400 discloses, in a third embodiment of the invention, a unidirectional automatic winding device equipped with an oscillating mass pivoted by two radial ball clutches mounted in opposition. A first clutch makes it possible to establish an unidirectional connection between the oscillating mass and the ratchet in a first direction of rotation of the oscillating mass. In a second direction of rotation of the oscillating mass, balls keep the automatic movement train in position and thus perform the same function as a pawl, notably a ratchet pawl. Such a configuration advantageously allows the use of a simplified automatic movement train the dead angle of which is minimized. However, just like the aforementioned Zenith caliber, such a timepiece is unable to operate independently of its automatic movement.
It is an object of the invention to provide a horology pawl system that makes it possible to overcome the aforementioned disadvantages and to improve the horology pawl systems known from the prior art. In particular, the invention proposes a horology pawl system such that the timepiece it equips can also operate without the automatic winding module and/or such that the automatic winding module does not need to overcome a resistive torque induced by a pawl.
A system according to the invention is defined in point 1 below.
Embodiments of the system are defined in points 2 to 10 below.
A movement according to the invention is defined in point 11 below.
Embodiments of the movement are defined in points 12 to 15 below.
A timepiece according to the invention is defined in point 16 below.
An embodiment of the timepiece is defined in point 17 below.
A method for configuration according to the invention is defined in point 18 below.
The attached figures depict, by way of examples, three embodiments of a timepiece according to the invention.
A first embodiment of a timepiece 110 is described hereinafter with reference to
Advantageously, the watch movement comprises a frame 99, a horology barrel 3, a geartrain and an automatic movement or automatic winding device. The automatic winding device may be an automatic winding module M′ as depicted in
For preference, the automatic movement is bi-directional, and may notably comprise reversing wheels 4, 4′. The two reversing wheels 4, 4′ on the one hand allow the ratchet to be driven by a transmission of movement from the oscillating mass 5 in the direction of coiling of a mainspring and, on the other hand, allow the ratchet to be immobilized in the direction of unwinding of the mainspring under the effect of the oscillating mass 5 as depicted in
The movement comprises a pawl system for a wheel 2 of the drivetrain for winding the horology barrel 3, namely a pawl system for immobilizing a wheel 2 of the drivetrain for winding the horology barrel 3.
The pawl system comprises:
The activation and deactivation element is arranged in such a way that, when the activation and deactivation element is in a first configuration (depicted in
In other words, the activation and deactivation element comprises:
In the various embodiments described, for preference, in the second configuration of the activation and deactivation element, the at least one tooth 1a of the pawl does not collaborate with the toothset 2a.
Advantageously, the pawl and the barrel ratchet are secured together in the first activation configuration or the first activation position of the activation and deactivation element, and the pawl and the barrel ratchet are disconnected in the second deactivation configuration or the second deactivation position of the activation and deactivation element.
In a first alternative form of the first embodiment depicted in
The pawl comprises the at least one tooth 1a, notably two teeth in this first alternative form of the first embodiment, some distance away from the fixing element. For preference, the at least one tooth 1a is positioned at a second end of the pawl. The tooth or teeth have, for example, a profile similar to those of the teeth of the toothset 2a.
The pawl further comprises a flexible portion 1b between the fixing element 1c and the at least one tooth 1a. This portion has for example an elongate shape like a stick or an arm. For preference, in the pawl activated first configuration depicted in
The pawl 1 is therefore monostable. Its first position is a position in which the at least one tooth is returned into contact with the toothset 2a. Thus, the stable position is a position in which the at least one tooth collaborates by obstacle with the toothset 2a and therefore a position in which the pawl prevents the wheel 2 from rotating, in particular prevents the wheel 2 from rotating in the direction of uncoiling or unwinding of the mainspring.
In the embodiment depicted, the activation and deactivation element is a means of assembly 6. This means of assembly allows any device to be assembled on the movement. Advantageously, the means of assembly allows an automatic movement, particularly an automatic winding module M′, to be assembled on the movement.
In the embodiment depicted, the means of assembly is a screw 6.
As seen previously, a first configuration of the activation and deactivation element is such that the at least one tooth 1a of the pawl collaborates by obstacle or interference with the toothset 2a, and a second configuration of the activation and deactivation element is such that the at least one tooth 1a of the pawl does not collaborate with the toothset 2a or such that the at least one tooth 1a of the pawl is less firmly engaged in the toothset 2a.
Advantageously, the first configuration is a first position of the activation and deactivation element and the second configuration is a second position of the activation and deactivation element.
Advantageously, as depicted in
Advantageously, the means of assembly has a second portion 6b, notably a second portion of a second diameter. This second portion is for example threaded and intended to be screwed into a tapping made in the frame 99, for example on a barrel bridge M1. For preference, when a watchmaker removes the means of assembly, before this means has been completely removed, the means of assembly is in its first position or configuration. In this first position, the pawl is in contact with or bearing against the second portion, the pawl being elastically returned against this second portion by its flexible portion. It then follows that the at least one tooth is returned to a position in which it forms an obstacle or interferes with the toothset 2a, as depicted in
The first and second portions are advantageously connected by a ramp, notably by a frustoconical shaping or a chamfer 6c.
Of course, the screw 6 could be replaced by a pin attached to or formed as one with a blank or by an eccentric 6′, as illustrated on
For preference, the activation and deactivation element and the pawl are arranged in such a way that the at least one tooth of the pawl is moved, relative to the wheel 2, in the plane of the movement or in the plane of the wheel 2 when the activation and deactivation element moves from its first position into its second position or when the activation and deactivation element moves from its second position into its first position.
However, in a second alternative form of the first embodiment of the pawl depicted in
A second embodiment of a timepiece 110′ is described hereinafter with reference to
The movement comprises a pawl system for a wheel 2 of the drivetrain for winding the horology barrel 3, namely a pawl system for immobilizing a wheel 2 of the drivetrain for winding the horology barrel 3.
This second embodiment differs from the first embodiment in that it comprises a second embodiment of a pawl system 1′.
In the second embodiment, the pawl 10′ comprises an assembly element 1c′ for assembly to the frame 99 of the movement 100′. The assembly element is preferably located at a first end of the pawl. The assembly element comprises for example a shaping such as a heel 1c′ provided with a hole for the passage of a spindle. In the second embodiment, the assembly element is a pivot element designed to pivot the pawl on the frame.
As in the first embodiment, the pawl comprises the at least one tooth 1a′ some distance away from the assembly element. For preference, the at least one tooth 1a′ is positioned at a second end of the pawl. In this embodiment, the at least one tooth has the shape of a jumper beak.
Unlike in the first embodiment, the pawl comprises a rigid portion 1d′ between the pivot element 1c′ and the at least one tooth 1a′. This portion has for example an elongate shape like an arm. This rigid portion experiences no or almost no deformation during normal operation of the pawl system.
For preference, in the first, activated, configuration of the pawl, the at least one tooth is returned into contact with the toothset 2a. In this first configuration, the pawl is loaded and presses the at least one tooth into the toothset 2a. This loading is obtained by an elastic arm 1b′ of the pawl. In the first configuration, the elastic arm is deformed or preloaded to bear against the activation and deactivation element 6′, which in this instance is a screw 6′, notably a screw 6′ provided with a frustoconical portion designed to collaborate with the elastic arm 1b′. In this embodiment, the elastic arm 1b′ which acts like a spring is formed as one with the rigid body 1d′ of the pawl. Alternatively, the spring may also be attached. It may be arranged to bear directly or indirectly against the rigid body.
The pawl 1′ is therefore monostable. Its first position is a position in which the at least one tooth is returned into contact with the toothset 2a. Thus, this first position is a position in which the at least one tooth collaborates by obstacle with the toothset 2a and therefore a position in which the pawl prevents the wheel 2 from rotating, particularly prevents the wheel 2 from rotating in the direction of uncoiling or unwinding of the mainspring.
A third embodiment of a timepiece 110″ is described hereinafter with reference to
The movement comprises a pawl system for a wheel 2 of the drivetrain for winding the horology barrel 3, namely a pawl system for immobilizing a wheel 2 of the drivetrain for winding the horology barrel 3.
This third embodiment differs from the first embodiment in that it comprises a third embodiment of a pawl system 1″.
In the third embodiment, the pawl 10″ differs from the pawls of the first and second embodiments in that it is made as two components: the actual pawl proper 10″ and a separate spring 1b″. The spring 1b″ is designed to apply load to the pawl and to return it to its first position.
As in the second embodiment, the pawl comprises a rigid portion 1d″ between a pivot element 1c″ and the at least one tooth 1a″. This rigid portion experiences no or almost no deformation during normal operation of the pawl system.
For preference, in the first, activated, configuration of the pawl, depicted in
For example again, in a second, deactivation, configuration or a second, deactivation, position, the activation and deactivation element causes deactivation of the pawl or lesser activation of the pawl, which means to say that the at least one tooth 1a″ of the pawl does not collaborate with the toothset 2a or that a return force returning the at least one tooth 1a″ of the pawl against the toothset 2a is reduced.
In all the embodiments and alternative forms described, the wheel 2 is a barrel ratchet. However, the wheel 2 can also be any other wheel in the barrel winding train, notably the automatic winding train or the manual winding train. The wheel could even form part of another train in mesh with the barrel.
In all the embodiments and alternative forms described, if the activation and deactivation element is a screw for assembling the automatic winding module, as soon as the screw is unscrewed during the dismantling of the automatic winding module, the pawl switches from the second configuration to the first configuration in which the at least one tooth 1a, 1a′, 1a″ of the pawl is in mesh with the toothset 2a, notably under the effect of a spring.
In all the embodiments and alternative forms described, the activation and deactivation element is a means of assembly. Alternatively, the activation and deactivation element may have any other function. The activation and deactivation element may also be dedicated to the single activation and deactivation function alone. The activation and deactivation element may for example comprise an eccentric.
In all the embodiments and alternative forms described, the stiffness of the pawl spring may be inhibited, so as to significantly minimize the resistive torque of the pawl during operation of the automatic winding device. In such a configuration, the pawl is preferably a jumper 1′ as in the second embodiment.
In all the embodiments and alternative forms described, the pawl is monostable. Thus, it retracts from the toothset 2a against the action of a spring that is set at the time of retraction. The elastic stiffness of the spring can also be inhibited. The restitution or the resetting of the spring causes the pawl to return to the position of the first configuration.
Alternatively, the pawl may take the form of a bistable rocker lever, namely a rocker lever provided with two stable positions, which are defined, for example, by flexible structures, notably by the buckling of one or more flexible leaves. In such a configuration, the state of the rocker lever in its first position or in its second position is dictated by the state of the activation and deactivation element.
As was seen earlier, the pawl may be a one-piece component as illustrated in
As seen previously, the pawl is designed to collaborate directly with a ratchet wheel 2. What is meant here by “directly” is that the pawl is preferably designed to come into mesh with the toothset of the ratchet. Alternatively, the pawl may collaborate with the toothset of another geartrain of the movement manual winding train which is in mesh with the ratchet wheel. The pawl may for example collaborate with the crown wheel which is in mesh with the ratchet wheel. In such a case, the principle of operation is entirely unchanged. As an alternative still, the crown wheel or any other geartrain in the manual winding train which is indexed by such a pawl may have a degree of freedom in such a way as to be able to be retracted from the toothset of the ratchet under the effect of the automatic winding module, and more particularly of the means of assembly of the automatic winding module. To this end, such a geartrain could, for example, be pivoted by an olived tenon or by a rocker lever.
Whatever the embodiment, the pawl is positioned in its first configuration as soon as the oscillating mass is removed, and preferably just before the oscillating mass is removed. In this way, any risk of untimely uncoiling of the mainspring is avoided. For preference, the automatic winding module M′ is designed in such a way that the oscillating mass cannot be removed from the movement before the module has been removed, and notably before a screw the state of which dictates the state of the pawl has been unscrewed. For preference, in one particular construction, a screw 7 for assembling and dismantling the oscillating mass 5 is not accessible while the automatic winding module M′ is assembled on the movement. The screw 7 is for example fitted from the underside of the automatic winding module M′, as illustrated in
Advantageously, the horology movement with automatic winding offers the particular feature of being provided with a disengagable pawl or pawl that can be activated and deactivated according to the state of assembly of the horology movement. Thus, it is possible to inhibit the function of the pawl during actuation of the automatic winding device and to activate the function of the pawl when the automatic winding device is removed from the movement. As a result, during operation of the automatic winding device, the oscillating mass does not need to overcome the resistive torque induced by the pawl, and notably the pawl spring, in order to allow automatic winding of the mainspring. Such a solution is particularly advantageous regarding its simplicity and the expected advantages.
In one preferred embodiment, the automatic winding movement offers the particular feature of being provided with a pawl that can be activated and deactivated according to the state of assembly of an automatic winding module M′.
In a first configuration or state of assembly of the movement corresponding to the horology movement without the automatic winding module, the pawl is activated in such a way as to immobilize the ratchet in the direction of unwinding of the mainspring. During operation of the movement without the automatic winding module, the pawl retracts during the winding but is immediately returned to a configuration of interference with a toothset so as to avoid any movement of the toothset in the direction of unwinding of the barrel.
In a second configuration or state of assembly of the movement corresponding to the horology movement with the automatic winding module, the pawl is deactivated so as to avoid interference with a toothset. For example, the at least one tooth of the pawl is out of reach of the toothset so as not to oppose the movement of the oscillating mass during operation of the automatic winding module.
In this particular construction, the automatic winding module M′, particularly the means of assembly of the automatic winding module on the movement, governs the state of the ratchet pawl to configure it into its activated or deactivated state. For example, as was seen earlier, an assembly screw for assembling the automatic winding module on the movement may exhibit a specific shaping which allows it to move, or to cause to move, notably in the plane of the frame of the movement, the pawl during assembly and dismantling of the automatic winding module M′. To achieve this, the screw 6 may, as was seen earlier, have a body portion 6a shaped to come into contact with the pawl as the screw 6 is screwed onto the rest of the movement M, particularly onto a barrel bridge M1. For preference, the screw 6 has at least two distinct portions 6a, 6b separated by a chamfer 6c so that the latter constitutes a ramp to allow the pawl to be moved, and therefore allow at least one tooth 1a, 1a′, 1a″ to be moved away from the toothset 2a as the screw 6 is screwed in. Thus, at the start of the screwing-in of the screw 6, the pawl is in a first configuration and, at the end of the screwing-in of the screw 6, the pawl is in a second configuration. Advantageously, in the second configuration of the activation and deactivation element 6, the mainspring is kept under tension under the effect of the automatic movement.
The various embodiments relate to a movement with automatic winding, which has the particular feature of being provided with a pawl that can be disengaged or deactivated according to the state of assembly of an automatic winding module M′. More generally, the horology movement with automatic winding exhibits the particular feature of being provided with a pawl that can be activated and deactivated according to the state of assembly of the horology movement, particularly according to the state of assembly of the horology movement to the framework. For example, the pawl may be deactivated upon final assembly of the movement within a watch case. The pawl may, for example, be deactivated by an element of the case such as the case back. For example, the case back may be provided with a pin that is designed to collaborate with the pawl so that the latter is retracted from a toothset of the ratchet once the case back of the case has been assembled. Such a design also makes it possible to inhibit or deactivate the pawl upon actuation of the automatic winding device, and to guarantee activation of the pawl when the automatic movement is removed from the movement once the movement has been taken out of the case. Such a design is particularly well suited to a movement provided with an oscillating mass that does not cover the entire movement, for example for a movement of the microrotor type.
Optionally, such a device may also be driven by an additional control, for example by the stem of the horology movement. Thus, the activation and deactivation element can have its state changed under the effect of an ancillary device, which is preferably activated by a mechanism at the stem of the horology movement. For example, the activation and deactivation element may have an elastic structure or an additional degree of freedom so that it can be retracted.
Advantageously, a horology movement as described hereinabove or a timepiece as described hereinabove is configured by employing at least one of the following steps:
For preference, the first step mentioned hereinabove is implemented during a method of dismantling the horology movement or the timepiece.
For preference, the second step mentioned hereinabove is implemented during a method of assembling the horology movement or the timepiece.
In this whole document, the term «pawl» or «click» preferentially means a mechanism for stopping a part (usually a wheel or a ratchet) in a first direction only and for allowing it to rotate in a second direction (opposite to the first direction). In a watch, the pawl prevents the ratchet-wheel from turning backwards when the winding-action stops. The pawl may be a lever provided with a beak which engages in the teeth of a wheel, under the action of a spring.
In this whole document, the term «activated pawl» preferentially means that the pawl stops the part in the first direction only and allows it to rotate in the second direction.
In this whole document, the term «deactivated pawl» or «unclicked pawl» preferentially means that the pawl allows the part to rotate in both first direction and second direction.
| Number | Date | Country | Kind |
|---|---|---|---|
| 17155912 | Feb 2017 | EP | regional |
| Number | Name | Date | Kind |
|---|---|---|---|
| 101398 | Woerd | Mar 1870 | A |
| 946385 | Mehl | Jan 1910 | A |
| 3673791 | Zaugg | Jul 1972 | A |
| 3733917 | Nikles et al. | May 1973 | A |
| 6485172 | Takahashi et al. | Nov 2002 | B1 |
| 20170123376 | Bertrand | May 2017 | A1 |
| Number | Date | Country |
|---|---|---|
| 542 468 | Nov 1973 | CH |
| 707741 | Sep 2014 | CH |
| 203054455 | Jul 2013 | CN |
| 1 136 892 | Sep 2001 | EP |
| 1041458 | Oct 2010 | EP |
| 1 528 337 | Jun 1968 | FR |
| 2 064 452 | Jul 1971 | FR |
| 2015193400 | Dec 2015 | WO |
| Entry |
|---|
| Testori, Leonard, English Translation of CH707741, originally published on Sep. 15, 2014, retrieved from Escpacenet on Sep. 19, 2019, full document (Year: 2014). |
| B. Humbert, “Swiss watches with automatic winding”, Ed. Scriptar SA, Lausanne, Switzerland, 1960, pp. 170-174 (with English machine translation; cited in the specification; 14 pages). |
| European Search Report and Written Opinion dated Sep. 4, 2017 issued in counterpart application No. EP17155912; w/ English machine translation (16 pages). |
| Chinese Office Action and Search Report dated Sep. 29, 2020 in counterpart application No. CN201810146238.3; with English machine-translation (total 22 pages). |
| Number | Date | Country | |
|---|---|---|---|
| 20180231934 A1 | Aug 2018 | US |
