EP4459381A1

EP4459381A1 - Movement for a watch and module for such a movement

Info

Publication number: EP4459381A1
Application number: EP23170924.7A
Authority: EP
Inventors: Eola Jessica Giuffre; Robyn Frances Louise GERLACH; Aleksandar JOVIC; Gerard Dunning
Original assignee: Flexous Mechanisms Ip BV
Current assignee: Flexous Mechanisms Ip BV
Priority date: 2023-05-01
Filing date: 2023-05-01
Publication date: 2024-11-06
Also published as: CN118884796A

Abstract

The invention relates to a movement (1) for a watch, which movement comprises a first layer (2) comprising a compliant mechanism, preferably a monolithic compliant mechanism (3), for a function or at least part of a function of the movement, an energy storage (16), and a second layer (15) comprising a gear train (17) for transmitting energy from the energy storage to the compliant mechanism to perform the function or part of the function and/or for transmitting energy from the compliant mechanism to the energy storage. The first layer (2) comprises a further compliant mechanism (20, 30, 40) for a further function or at least part of a further function of the movement.

Description

The invention relates to a movement for a watch, which movement comprises a first layer comprising a compliant mechanism, preferably a monolithic compliant mechanism, for at least part of a function of the watch movement - such as an oscillator or an anchor or anchor teeth or the combination of an oscillator and an anchor or anchor teeth or automatic winding - an energy storage, such as a main spring, and a second layer comprising a gear train for transmitting energy from the energy storage to the compliant mechanism to perform the (part of the) function and/or for transmitting energy from the compliant mechanism to the energy storage, e.g. if the latter involves hand winding or automatic winding. The invention also relates to a module for a watch movement comprising compliant (flexible) mechanism technology.
Typically, mechanical watches are comprised of many small moving components which interact with each other via rigid links, axes and bearings. Incorporating compliant mechanism technology, where forces and motion are transferred via flexible elements, allows for a significant reduction in wear and a simplification of assembly.
NL 2024076 relates to a mechanical watch comprising an oscillator embodied with a vibratory mass or masses, wherein each vibratory mass connects to least one flexural member. The watch further comprises an escape wheel and anchor teeth that are connected to the vibratory mass or masses, which anchor teeth cooperate with the escape wheel, and wherein the anchor teeth are provided on at least one of the flexural members.
WO 2018/100122 relates to a device for a timepiece, comprising a base, an inertial regulating organ mounted to rotate relative to the base, by means of an elastic suspension means connecting the regulating organ to the base. The device comprises an anchor adapted to engage with an energy distribution member provided with teeth and intended to be urged by an energy storage device, said anchor being controlled by said regulating member to regularly and alternately block and release the energy distribution member.
It is an object of the present invention to provide an improved movement for a watch.
To this end, the first layer comprises a further compliant mechanism for a further function or at least part of a further function of the movement.
In an embodiment, the further compliant mechanism is coupled or couplable, i.e. configured to be capable of being coupled and/or decoupled, to the gear train for transmitting energy, e.g. torque and rotation, from the energy storage to the further compliant mechanism to perform the further function and/or for transmitting energy from the further compliant mechanism to the energy storage.
With the present invention in-plane alignment of the two or more compliant mechanisms can be greatly improved, e.g. be more accurate and/or inherently present and/or fits more precisely on or over components, e.g. one or more shafts, in a different layer of the movement. Also, the number of individual parts in the movement can be further reduced and/or assembly of the movement simplified.
In an embodiment, the first layer provides a frame and two or more of the compliant mechanisms are supported by and/or in the frame, preferably by means of elastic links, also known as flexures.
In an example, the first layer comprises an opening with inwardly extending flexures, e.g. two or four inwardly extending flexures, and an oscillator mass suspended in the opening and from the frame by these flexures. The mass can comprise two or more mass sections interconnected by further flexures, which flexures are not directly connected by to the frame. Also, two of the flexures can be provided with anchor teeth while an escape wheel, mounted on a shaft of one of the gears in the gear train, is located between the anchor teeth such that these teeth alternately hold and release the (teeth of the) escape wheel when the oscillator mass oscillates. Such inside-outside configurations, wherein the ground or frame at least partially surrounding the oscillator (as opposed to a central ground or frame to suspend the oscillator mass) facilitates providing two or more (parts of) functions in a single layer.
To further improve in-plane alignment and add improved out of plane alignment, in an embodiment, the two or more compliant mechanisms and, if present, the frame and/or elastic links, in the layer are monolithic, e.g. defined, typically etched, in the same wafer, and preferably made from silicon, beryllium copper, or steel.
Thus, tolerance stacking is avoided and tolerances between the compliant mechanisms and the components of the compliant mechanism can be practically zero, e.g. 50 nm (nanometers) ± 1 nm, and/or be essentially equal to the tolerance of the wafer stepper that was used to make the monolithic layer containing the compliant mechanisms.
In principle all contacts and interactions in the layer will benefit in terms of improved accuracy and efficiency, reduced wear, and/or, during production, improved reproducibility and yield.
In an embodiment, the gear train in the second layer comprises conventional gears and/or a conventional mainspring, i.e. the gears and/or mainspring are all metal. In another embodiment, the gears are etched from silicon.
In an embodiment, the gears and/or mainspring are supported on at least one side by a bridge or plate in conventional bearings, such as 'jewels' in particular rubies, for the pivots, also referred to as shaft or staffs, of the gears and/or mainspring.
The gear train transmits torque from the energy storage, typically a (spiral) mainspring, to the escapement. Most or each of the gears comprise a wheel and a pinion on a pivot and the gears are arranged to multiply motion/rotation. In a multiplying gear train, the output rotates faster than the input. More specifically, the gear train is also responsible for dividing time into useful segments - hours, minutes, and seconds. Beyond its usefulness, a gear train is visually compelling/pleasing because of its constant motion.
In an embodiment, the first layer comprises an opening and a bridge or plate supporting one side of the conventional gears and/or the conventional mainspring is at least partially accommodated in the opening, providing a compact hybrid configuration of conventional gears and/or main spring and e.g. a monolithic layer containing two or more functions.
In another embodiment, the gears and/or mainspring are supported on one side by the first, preferably monolithic, layer and on the other side by a further, preferably monolithic, layer, both layers comprising one or more recesses or openings, e.g. openings provided with bearing elements or round, etched recesses or holes serving as bearings, for the pivot(s) of the gears and/or main spring.
Thus, the movement can be ultraflat and e.g. comprise or essentially consist of three layers, e.g. a conventional mainspring and gear train sandwiched between two monolithic layers, one monolithic layer defining two or more compliant mechanisms and the other monolithic layer providing bearings for the main spring and/or gears in the gear train and optionally even one or more further compliant mechanisms, e.g. an oscillator plus escape wheel and a chronograph in one layer and automatic winding and/or keyless works in the other layer. In another example, the other ('lower') monolithic layer also functions as (part of) the case back of the watch case and, in a refinement, is made from a transparent material, such as sapphire glass, to provide a see-through case back.
These measures would potentially enable a watch having an overall height (including case back, movement, and glass/sapphire) of less than 2,0 mm or a chronograph watch having an overall height of less than 3,0 mm.
In an embodiment, the compliant mechanisms in the first layer include at least two of: an oscillator - in particular an oscillator having anchor teeth on the oscillating mass and/or on the flexures, to cooperate with an escape wheel to form an escapement -, an anchor, automatic winding, manual winding, a motion invertor, a click mechanism, keyless works (typically combining a motion invertor and a click mechanism), a start/stop and/or reset mechanism, e.g. of a chronograph or flyback chronograph split-seconds chronograph, a chronograph or flyback chronograph, a split-seconds chronograph, a moon phase, retrograde date, an annual calendar, a perpetual calendar, and minute repetition.
In an embodiment, at least one of the compliant mechanisms is modularly fitted, e.g. shape-fitted or force-fitted, e.g. clamped or pressed, in the first layer. Amongst other things, modularly fitted mechanisms allow relatively straight-forward replacement and tuning.
In an embodiment, the first layer comprising the two or more compliant mechanisms and, if present, the further layer comprising one or more compliant mechanisms has a thickness smaller than 1000 µm, preferably smaller than 800 µm, preferably smaller than 700 µm, preferably smaller than 600 µm, e.g. in a range from 100 µm to 550 µm, e.g. in a range from 250 µm to 500 µm, and/or the layer(s) is (are) monolithic.
In an embodiment, the layer comprising the two or more compliant mechanisms and, if present, the further ('lower') layer are shaped by means of laser cutting or etching, in particular reactive ion etching, such as RIE or DRIE, and are preferably made from silicon, beryllium copper, or steel.
The invention also relates to a module, in particular a layer, e.g. a plate having a thickness as defined above, for a movement as described above, the module comprising a compliant mechanism, preferably a monolithic compliant mechanism, for a function of the movement and optionally other elements of the first layer as described above.
The invention also relates to a watch movement as described above, wherein the gear train comprises a center wheel, a third wheel, and a fourth wheel, to transmit torque and energy to the escape wheel, as well as a wrist watch comprising such a movement.
Below, the invention will be explained further, which reference to the appended figures in which an embodiment of the invention is shown.

Figure 1 is a top plan view of a movement according to the present invention.
Figure 2 is a perspective view of the movement shown in Figure 1.
Figure 3 is a perspective view of the movement shown in Figures 1 and 2, provided with a shock protection layer.

Figure 1 shows a movement 1 for a watch, which movement comprises a first layer 2, e.g. made from silicon, such a 111 silicon, which provides a frame supporting two or more compliant and preferably monolithic mechanisms. In this example, the first layer comprises an oscillator 3. More specifically, the first layer comprises an opening 5 with inwardly extending flexures 6, e.g. four inwardly extending flexures, and an oscillator mass 7 comprising two or more, i.c. two, mass sections interconnected by further flexures 8. Two of the flexures are provided with anchor teeth 10, while an escape wheel 11, mounted on a shaft of one of the gears in a gear train (discussed below) in another layer, is located between the anchor teeth such that these teeth alternately hold and release the (teeth of the) escape wheel when the oscillator mass oscillates. The oscillator may have a natural frequency of 15 Hertz (Hz) or higher, preferably 25 Hz or higher, preferably 35 Hz or higher. In extreme instances, natural frequencies could be up to 100 Hz or even higher.
The movement 1 comprises a second layer 15 in turn comprising an energy storage, such a main spring in a barrel 16, and a gear train 17 for transmitting energy from the energy storage to the compliant mechanism to perform the function, i.c. oscillate.
More specifically, the example shown comprises conventional gears 17 and a conventional mainspring 16, i.e. the gears and mainspring are all made from metal. The gears and mainspring are supported, in a traditional fashion, on both sides by a bridge or plate in conventional bearings, such as 'jewels' in particular rubies, for the pivots.
The first layer comprises one or more further compliant mechanisms that is/are coupled or couplable to the gear train for transmitting energy, e.g. torque and rotation, from the energy storage to the further compliant mechanisms to perform the further function and/or for transmitting energy from the further compliant mechanism to the energy storage. In this example, the first layer comprises i) a chronograph 20 having a start/stop mechanism 21A, 21B and a reset mechanism 22, ii) keyless works 30, comprising a motion invertor 30A and a click mechanism 30B, several suitable examples of which are described in EP 4 158 426 , and iii) a automatic winding mechanism 40.
Suitable examples of the chronograph are described in European patent application 22210664.3 . The example shown in Figures 1-3 comprises a start/stop mechanism 21A, 21B having at least two stable positions and operatively coupled to a brake mechanism 23 to move the brake mechanism between first and second positions, which controller mechanism is preferably coupled to a pusher 24 which enables a (human) user to actuate the controller. The brake mechanism has two or more brake elements movable towards and away from - defining stop and start position, respectively - a cam 25 which is coupled to a seconds hand on the dial side of the chronograph and which has, in this example, a single point or apex. When the brake elements have been moved towards the cam, the surfaces of the brake elements facing the cam form a ring having a smooth inner surface and hold the cam in place. The ring provides braking of the indicator at any position of the point or apex on the cam along a 360° rotation and maintains the indicator in the selected position. During reset, the plurality of brake elements move away from the cam provide a passage for a reset element, e.g. a resiliently and translatably mounted pin 26, to interact with the cam to reset the indicator to a default position.
The automatic winding mechanism 40 comprises an inertial weight 41 suspended, preferably monolithically suspended, from the first layer by two flexures 42 and provided with a ratchet mechanism 43 to convert oscillation of the weight to winding of the main spring.
Further, in the example shown, the first layer comprises an opening 50 and a bridge or plate supporting one side of the conventional gears and mainspring is at least partially accommodated in the opening, providing a compact hybrid configuration of conventional gears and/or main spring and e.g. a monolithic layer containing two or more functions.
The invention is not limited to the described embodiments and can be varied within the scope of the claims. For instance, as shown in Figure 3, a shock protection, in this case a further layer that is mounted on the first layer and serves as an out-of-plane stopper for at least some of the compliant components in the first layer. The purpose of the shock protection is to limit the distance the, e.g. silicon, masses in the first layer can displace in the direction perpendicular to the face of the movement when experiencing shocks.

Claims

Movement (1) for a watch, which movement comprises a first layer (2) comprising a compliant mechanism, preferably a monolithic compliant mechanism (3), for a function or at least part of a function of the movement, an energy storage (16), and a second layer (15) comprising a gear train (17) for transmitting energy from the energy storage to the compliant mechanism to perform the function or part of the function and/or for transmitting energy from the compliant mechanism to the energy storage, characterized in that the first layer (2) comprises a further compliant mechanism (20, 30, 40) for a further function or at least part of a further function of the movement.
Movement (1) according to claim 1, wherein the further compliant mechanism (20, 30, 40) is coupled or couplable to the gear train (17) for transmitting energy from the energy storage (16) to the further compliant mechanism ((20, 30, 40) to perform the further function and/or for transmitting energy from the further compliant mechanism (40) to the energy storage (16).
Movement (1) according to claim 1 or 2, wherein the first layer (2) provides a frame and two or more of the compliant mechanisms (3; 20, 30, 40) are supported by and/or in the frame.
Movement (1) according to claim 3, wherein two or more of the compliant mechanisms (3; 20, 30, 40) are supported in the frame by means of elastic links.
Movement (1) according to any one of the preceding claims, wherein the two or more compliant mechanisms (3; 20, 30, 40) and, if present, the frame and/or elastic links, in the layer are monolithic and preferably made from silicon, beryllium copper, or steel.
Movement (1) according to any one of the preceding claims, wherein the gear train (17) in the second layer (15) comprises conventional gears (17) and/or a conventional mainspring (16).
Movement (1) according to claim 6, wherein the gears (17) and/or mainspring (16) are supported on at least one side by a bridge or plate in conventional bearings and/or wherein the first layer (3) comprises an opening (50) and a bridge or plate supporting the conventional gears and/or a conventional mainspring is at least partially accommodated the opening.
Movement (1) according to any one of the claims 1-6, wherein the gears (17) and/or mainspring (16) are supported on one side by the first layer (3) and on the other side by a further layer, both layers comprising one or more recesses or openings, such as openings provided with bearing elements or round, etched recesses or holes serving as bearings, for the shaft(s) of the gears (17) and/or main spring (16) .
Movement (1) according to any one of the preceding claims, wherein the compliant mechanisms in the first layer include at least two of an oscillator (3), an anchor, automatic winding (40), manual winding, a motion invertor (30A), a click mechanism (30B), keyless works (30), a start/stop, a reset mechanism, a chronograph (20) or flyback chronograph, a split-seconds chronograph, a moon phase, retrograde date, an annual calendar, a perpetual calendar, and minute repetition.
Movement (1) according to any one of the preced-ing claims, wherein at least one of the compliant mechanisms (3; 20, 30, 40) is modularly fitted in the first layer.
Movement (1) according to any one of the preceding claims, wherein the first layer and, if present, the further layer has a thickness smaller than 1000 µm, preferably smaller than 800 µm, preferably smaller than 700 µm, preferably smaller than 600 µm, e.g. in a range from 300 µm to 550 µm, e.g. in a range from 250 µm to 500 µm, and/or wherein the layer(s) is (are) monolithic.
Movement (1) according to any one of the preceding claims, wherein the layer comprising the two or more compliant mechanisms and, if present, the further layer were shaped by means of reactive ion edging, such as RIE or DRIE, and are preferably made from silicon, beryllium copper, or steel.
Module (3) for a movement (1) according to any one of the preceding claims, the module comprising a compliant mechanism, preferably a monolithic compliant mechanism (3), for at least part of a function of the movement and one or more of the elements of the first layer specified in any one of the preceding claims.
Movement (1) according to any one of the preceding claims, comprising a shock protection, preferably a further layer that serves as an out-of-plane stopper.
Wristwatch comprising a movement or module according to any one of the preceding claims.