Classifications

• • G—PHYSICS
  • G04—HOROLOGY
  • G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
  • G04B1/00—Driving mechanisms
  • G04B1/10—Driving mechanisms with mainspring
  • G04B1/22—Compensation of changes in the motive power of the mainspring
  • G04B1/225—Compensation of changes in the motive power of the mainspring with the aid of an interposed power-accumulator (secondary spring) which is always tensioned
• • G—PHYSICS
  • G04—HOROLOGY
  • G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
  • G04B15/00—Escapements
  • G04B15/10—Escapements with constant impulses for the regulating mechanism
• • G—PHYSICS
  • G04—HOROLOGY
  • G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
  • G04B15/00—Escapements
  • G04B15/14—Component parts or constructional details, e.g. construction of the lever or the escape wheel

Definitions

• a traditional mechanical watchmaking movement comprises an energy source, such as a barrel, a finishing gear driven by the power source, an escapement driven by the finishing gear and an oscillator whose oscillations are maintained by the 'exhaust.
• the oscillator (or regulator) is generally of the spiral balance type.
• the exhaust generally comprises an escape wheel (coaxial wheel and pinion and solidarity) and an anchor. The pinion of the escapement engages with the last wheel of the finishing train while the wheel of the escapement mobile cooperates with the anchor, which communicates pulses of mechanical energy to the oscillator.
• Some movements also include, in the work train between the energy source and the exhaust, a so-called “constant force” device, that is to say a device comprising an intermediate spring periodically armed with the same quantity by the source of energy and supplying its energy to the exhaust.
• a constant force device that is to say a device comprising an intermediate spring periodically armed with the same quantity by the source of energy and supplying its energy to the exhaust.
• Patent applications WO 99/64936, WO 2009/1 18310 and CH 705674 also disclose an escapement comprising a bistable blade armed by an armature rocker actuated alternately by two escape wheels.
• a trigger rocker secured to the region of the midpoint of the bistable blade imparts pulses of mechanical energy to the oscillator during changes in state of the bistable blade.
• the bistable blade is a "constant force" device that periodically supplies the same amount of energy to the oscillator via the trigger rocker.
• the member that communicates the pulses of mechanical energy to the oscillator whether in the form of a trigger rocker, an anchor or the like, is called “striker". The performance of a mechanical watch movement is low.
• the escapement transmits to the oscillator only a small part of the energy it receives.
• One of the causes of the observed energy losses are the friction between the different parts.
• the striker accompanies (remains in contact with) the oscillator on a pulse angle which is generally between 12 ° and 20 °.
• a pulse angle which is generally between 12 ° and 20 °.
• Such a chaotic transmission of energy between the striker and the oscillator is an additional obstacle to obtaining a good performance.
• the present invention aims at providing a clockwork movement with improved efficiency.
• a clockwork movement comprising a rotary oscillator around a first axis, a rotary firing pin around a second axis for communicating pulses of mechanical energy to the oscillator, a source of energy and a transmission device connecting the energy source to the striker, the transmission device comprising a constant force device for periodically storing a quantity of energy to be supplied to the striker, characterized in that said quantity of energy, the geometry of the striker and the moments of inertia of the striker and the oscillator are chosen so that at each pulse imparted to the oscillator by the striker the following relation is substantially satisfied:
• h is the moment of inertia of the striker with respect to the second axis
• h is the moment of inertia of the oscillator relative to the first axis
• ⁇ - ⁇ is the angular velocity of the striker just before the impulse gives to the oscillator
• ⁇ is the angular velocity of the oscillator just before said pulse
• di is the lever arm of the firing pin
• d2 is the lever arm of the oscillator.
• the striker transmits all its kinetic energy to the oscillator in a single shock and its velocity becomes zero immediately after the shock, so that the phenomenon of accompaniment between the striker and the oscillator and the energy losses it causes do not exist in the present invention.
• the present invention proposes a clockwork movement comprising a rotary oscillator about an axis, a linear motion firing pin for communicating pulses of mechanical energy to the oscillator, a source of energy and a transmission device connecting the energy source to the striker, the transmission device comprising a constant force device for periodically storing a quantity of energy to be supplied to the striker, characterized in that said quantity of energy, the geometry and the mass of the firing pin and the moment of inertia of the oscillator are chosen so that at each pulse imparted to the oscillator by the striker the following relation is substantially satisfied:
• mi is the mass of the striker
• I2 is the moment of inertia of the oscillator with respect to said axis, seen is the linear speed of the striker just before the impulse which it gives to the oscillator
• ⁇ is the angular velocity of the oscillator just before said pulse
• d2 is the lever arm of the oscillator.
• the present invention also proposes a method for producing a clockwork movement comprising a rotary oscillator around a first axis, a rotary striker around a second axis for communicating pulses of mechanical energy to the oscillator, a source of energy and a device transmission connecting the power source to the firing pin, the transmission device comprising a constant force device for periodically storing a quantity of energy to be supplied to the firing pin, the method comprising a motion design step followed by a step of manufacturing the firing pin; movement, the method being characterized in that during the design of the movement, said amount of energy, the geometry of the firing pin and the moments of inertia of the striker and the oscillator are chosen so that at each pulse imparted to the oscillator by the striker the following relation is substantially satisfied:
• h is the moment of inertia of the striker with respect to the second axis
• I2 is the moment of inertia of the oscillator relative to the first axis
• ⁇ - ⁇ is the angular velocity of the striker just before the impulse gives to the oscillator
• 0021 is the angular velocity of the oscillator just before said pulse
• di is the lever arm of the firing pin
• d2 is the lever arm of the oscillator.
• the present invention proposes a method for producing a clockwork movement comprising a rotary oscillator about an axis, a linear motion striker for communicating pulses of mechanical energy to the oscillator, a power source and a transmission device connecting the power source to the firing pin, the transmission device comprising a constant force device for periodically storing a quantity of energy to be supplied to the striker, the method comprising a step of motion design followed by a movement manufacturing step, the method being characterized in that during motion design, said amount of energy, the striker geometry and mass, and the moment of inertia of the oscillator are chosen so that at each pulse imparted to the oscillator by the striker the following relation is substantially satisfied:
• mi is the mass of the striker
• I2 is the moment of inertia of the oscillator with respect to the axis, seen is the linear velocity of the striker just before the impulse it gives to the oscillator
• ⁇ is the angular velocity of the oscillator just before said pulse
• d2 is the lever arm of the oscillator.
• FIG. 1 is a block diagram of a watch movement
• FIGS. 2 to 10 show, in plan view, different operating phases of a constant force escapement and an oscillator used in the present invention
• FIG. 1 1 shows in top view an exhaust striker and a double oscillator plate used in the present invention
• FIG. 12 shows a top view of a variant of the striker used in the present invention
• FIG. 13 shows in top view another variant of the striker used in the present invention.
• a mechanical clockwork comprises a power source 1, typically constituted by one or more barrels, a finishing gear 2, an escapement 3 and an oscillator 4.
• the source energy 1 and the work train 2 are conventional, they will not be described.
• the oscillator 4 is also of conventional type. It comprises, mounted on a balance shaft 6 of axis A, a balance spring (not shown) and a double tray.
• the double plate comprises a large plate 7, which carries a plate pin 8, and a small plate 9.
• the exhaust 3 is of the type described in the patent applications WO 99/64936, WO 2009/1 18310 and CH 705674. It thus comprises two exhaust mobiles (not shown), a bistable leaf spring 10, a flip-flop. arming 1 1 and striker or trigger rocker 12.
• the two exhaust mounts each comprise a pinion which meshes with the last wheel of the work train 2 and an escape wheel provided not with teeth but with cams each terminated by a locking stop.
• the two escape wheels respectively cooperate and alternately with exhaust pins 13 carried by the rocker 1 1.
• the armature rocker 1 1 and striker 12 pivot about the same axis B which corresponds to the midpoint of the leaf spring 10.
• the axis B is for example the axis of a rod driven into the armature rocker 1 1, pivoting in bearings of the frame of the movement and around which pivots the firing pin 12.
• the leaf spring 10 is integral with the striker 12 and with an outer frame (not shown) which surrounds the leaf spring 10, and consists of two elastic strips 10a, 10b each having an end joined to the firing pin 12 and another end attached to the outer frame, attached to the frame of the movement.
• the leaf spring 10 has two convexities of opposite directions on either side of its midpoint and can move from a first stable state to a second stable state by reversing the direction of each of the two convexities.
• the leaf spring 10 is either prestressed so as to work in buckling or preformed to, in the state of rest, already present two convexities as described in the international patent application WO 2017/032528 of the present applicant.
• the outer frame is deformable to allow buckling of the leaf spring 10.
• the outer frame is rigid.
• the rocker arm 1 1 comprises two arms 14 carrying at their ends two pins 14a, 14b engaged in eyelets (not shown) of the two resilient blades 10a, 10b respectively.
• a reverse configuration is of course possible where the pins 14a, 14b would be carried by the resilient blades 10a, 10b, respectively, to engage in the eyelets of the rocker 1 1.
• other modes of connection between the rocking lever 1 1 and the elastic blades 10a, 10b are conceivable, for example two pins at the end of each arm 14 of the rocker 1 1 pinching the blade corresponding elastic.
• the striker 12 comprises a body 15 surrounding the axis B and extended on one side by a fork 16-17 and on the other side by a tail 18.
• the fork 16-17 fulfills the function of an anchor fork conventional, ie cooperating with the plate pin 8 to communicate pulses of mechanical energy to the oscillator 4, and comprises for this purpose a first horn 16 and a second horn 17.
• a dart 19 secured to the striker 12 is likely to cooperate with the small plate 9 of the oscillator 4 to prevent the reversal of the firing pin 12 in the event of impact.
• the tail 18 is itself designed to cooperate with first and second limiting abutments 20, 21 fixed relative to the frame of the movement, for example one-piece with the aforementioned outer frame, to limit the angular displacement of the firing pin 12.
• the armature rocker 1 actuated by a winding cam of one of the escape wheels and acting symmetrically in the region of the two convexities of the leaf spring 10, deforms the leaf spring 10 from a first of its stable states to a metastable state close to an unstable state corresponding to a fourth mode buckling, for arming the leaf spring 10.
• This arming phase ends when the armature rocker 1 1 is blocked by a locking stop of the escape wheel with which it cooperates, which keeps the leaf spring 10 in its metastable state and immobilizes the two escape wheels, the work train 2 and the armature rocker 1 1 Then the striker 12 located in the region of the midpoint of the leaf spring 10 acts on the leaf spring 10 to make it exceed its unstable state and thus make it rock in its second stable state by releasing its energy. The energy enabling the firing pin 12 to deform the leaf spring 10 beyond its unstable state since its metastable state is provided by the oscillator 4, when the plate pin 8 collides with the horn 16 of the fork.
• This phase which requires only a small supply of energy, can be compared to the phase of release of an anchor escapement.
• FIGS. 2 to 10 show the different operating phases of the escapement and the oscillator.
• the oscillator 4 is in the acceleration phase and traverses the downward sinistral angle, the striker 12 bears against the limit stop 20 and the leaf spring 10 is at the end of the weave (metastable state ).
• the oscillator 4 is close to its maximum speed and begins to traverse the sinister lift angle, the horn 16 of the striker 12 is struck by the plate pin 8 (release, by a single shock) and the leaf spring 10 is unlocked (between the metastable state and the unstable state).
• FIG. 2 the oscillator 4 is in the acceleration phase and traverses the downward sinistral angle
• the striker 12 bears against the limit stop 20
• the leaf spring 10 is at the end of the weave (metastable state ).
• FIG. 3 the oscillator 4 is close to its maximum speed and begins to traverse the sinister lift angle, the horn 16 of the striker 12 is struck by the plate pin 8 (release, by a single shock
• the oscillator 4 is at its maximum speed and traverses the sinister lift angle, the striker 12 strikes by its horn 17 the plate pin 8 to impart to it an impulse (by a single shock as will be explained further) while the leaf spring 10 has just switched from the unstable state to the second stable state.
• the oscillator 4 decelerates and traverses the ascending ascending angle, the striker 12 is in abutment against the limit stop 21 and the leaf spring 10 is at the beginning of arming (it leaves the second stable state).
• the rotation of the oscillator 4 reverses (maximum elongation sinister), the striker 12 bears against the limit stop 21 and the leaf spring 10 is being wound (between the second state stable and metastable state).
• the oscillator 4 is close to its maximum speed and begins to traverse the dextral lifting angle, the horn 17 of the striker 12 is struck by the plate pin 8 (disengagement, by a single shock) and the leaf spring 10 is unlocked (between the metastable state and the unstable state).
• the oscillator 4 is at its maximum speed and traverses the dextral lifting angle, the striker 12 strikes by its horn 16 the plate pin 8 to impart to it an impulse (by a single shock as will be explained further) while the leaf spring 10 has just switched from the unstable state to the first stable state.
• the pulse angle that is to say the angle traveled by the firing pin between the beginning of the pulse and the end of the pulse, is between 12 ° and 20 °. In the present invention, however, this pulse angle is very small, typically less than 1, 5 ° or even 1 °. Indeed, during the design of the movement according to the invention, the various parameters of the movement, in particular the amount of mechanical energy stored in the leaf spring 10 to each of its armatures, the geometry of the striker 12 and the moments of the inertia of the firing pin 12 and the oscillator 4 are chosen in such a way that the firing pin 12 transfers all its kinetic energy to the oscillator 4 in a single shock (FIGS. 4 and 8), the firing pin 12 having a zero speed just after the shock, the residual energy in the leaf spring 10 then bringing the striker 12 bearing against one of the limit stops 20, 21 ( Figures 5 and 9).
• h is the moment of inertia of the striker 12 (including all the elements which rotate with it, like the stinger 19) with respect to its axis of rotation B,
• I2 is the moment of inertia of the oscillator 4 (including all the elements which rotate with it, like the balance shaft 6) with respect to its axis of rotation A,
• n is the angular velocity of striker 12 just before the pulse it gives to oscillator 4,
• ⁇ -if is the angular velocity of the striker 12 just after said pulse
• - or2i is the angular velocity of the oscillator 4 just before said pulse
• or2f is the angular velocity of the oscillator 4 just after said pulse
• di is the lever arm of the firing pin 12 (see FIG. 1 1), that is to say the distance between the axis of rotation B and the line of action of the reaction-action forces F2 and F1 exerted by the striker 12 and the plate pin 8 on the other at the moment of impact (pulse)
• d2 is the lever arm of the oscillator 4 (see FIG. the distance between the axis of rotation A and the line of action of the reaction-action forces F2 and F1 exerted by the striker 12 and the plate pin 8 on the other at the moment of impact ( impulse).
• the spacing E of the horns 16, 17 is greater than 1, 2 times, preferably 1 to 3 times, preferably 1 to 4 times, preferably 1 to 5 times, preferably 1 to 6 times, preferably 1 to 7 times, preferably 1 to 8 times, preferably 1, 9 times, more preferably 2 times, the diameter D of the plate pin 8.
• diameter of the plateau peg is meant its diameter strictly speaking, especially when the plateau peg is semi-shaped. circular as shown, or more generally its largest dimension perpendicular to the plane which contains the axis of rotation A of the oscillator 4 and which constitutes a plane of symmetry for the plate pin 8.
• the plate pin 8 may have other forms than that shown, for example the shape of a finger or a portion of a finger extending radially from an annular portion mounted on the balance shaft 6.
• the large spacing E horns 16, 17 promotes the exit of the pin 8 of the fork 16-17 after the pulse by allowing him, given the zero velocity striker 12, out of said range without touching the other horn that that has communicated the pulse. Thanks to this characteristic too, the performance of the escapement and the chronometry of the movement are improved.
• the pulse communicated by the firing pin 12 to the oscillator 4 occurs while the plate pin 8 is on the line of the centers, that is to say, while the plate pin 8 is traversed symmetrically by the plane containing the axis of rotation A of the oscillator 4 and the axis of rotation B of the striker 12.
• This position of the plateau pin 8 corresponds to the equilibrium position of the oscillator 4. Communicating the impulse on the line of the centers makes it possible not to affect the isochronism of the oscillator.
• the striker 12 (or at least the fork 16-17) and the pin 8 are each made of one of the following materials: steel, preferably tempered; aluminum oxide, preferably ruby, more preferably ruby obtained by the Verneuil process; silicon, preferably monocrystalline, preferably also coated with silicon oxide; metal glass. All combinations of these materials are possible to form the couple of materials of the firing pin 12 and the peg 8.
• FIGS. 2 to 1 1 The firing pin 12 illustrated in FIGS. 2 to 1 1 is balanced, in other words its geometry is chosen so that its center of gravity is situated on its axis of rotation B. Such a firing pin shape makes it insensitive to linear shocks received by the watch movement.
• Figure 12 shows a variant of the striker used in the present invention. According to this variant, the striker, designated by 12 ', is not balanced but instead has an unbalance that confers two arms 22, 23 which extend the horns 16, 17. These two arms 22, 23, located on the on the other side of the axis of rotation B with respect to the tail 18, replace said tail. They thus cooperate respectively with limiting stops 20 ', 21' to limit the angular movement of the firing pin 12 '.
• the imbalance of the striker 12 ' is chosen so that during shocks (pulses) communicated by the firing pin 12' to the plate pin 8, the reaction forces at the axis of rotation B are minimal, thus making it possible to optimize the transmission of energy between the striker 12 'and the oscillator 4 and thus the efficiency of the exhaust. More precisely, the imbalance of the striker 12 'is chosen so that the following relation is satisfied:
• mi is the mass of the striker 12 '
• di is the lever arm of the striker 12 ', that is to say the distance between the axis of rotation B and the line of action of the reaction-action forces F2 and F1 exerted by the striker 12' and the ankle plate 8 on top of each other at the moment of impact (impulse),
• h is the moment of inertia of the striker 12 'with respect to its axis of rotation B
• LG is the distance between the axis of rotation B of the striker 12 'and the line parallel to the line of action of the forces F2, F1 and passing through the center of gravity G of the firing pin 12'.
• the horns 16, 17 could be part of the oscillator 4 and the plate pin 8 could be part of the firing pin 12;
• the oscillator 4 could be of the flexible pivot type; instead of being mounted on a physical axis, the firing pin 12 could also be of the flexible pivot type.
• the present invention is not limited to a rotary striker.
• the firing pin can indeed be mobile in translation rather than in rotation, like the striker 12 "illustrated in FIG. 13.
• Such a mobile firing pin can be actuated for example by a mobile frame of the type described in the patent application WO 2013/144236.
• mi is the mass of the striker 12 "(including all the elements that move with it, like the sting 19),
• I2 is the moment of inertia of the oscillator 4 (including all the elements which rotate with it, like the balance shaft 6) with respect to its axis of rotation A,

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• Micromachines (AREA)
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• 2017
  • 2017-06-21 EP EP17733911.6A patent/EP3479175B1/de active Active
  • 2017-06-21 WO PCT/IB2017/053706 patent/WO2018002778A1/fr unknown

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