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
  • G04B17/00—Mechanisms for stabilising frequency
  • G04B17/04—Oscillators acting by spring tension
  • G04B17/045—Oscillators acting by spring tension with oscillating blade springs
• • 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
  • G04B15/06—Free escapements
  • G04B15/08—Lever escapements
• • 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
• • 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
  • G04B18/00—Mechanisms for setting frequency
  • G04B18/04—Adjusting the beat of the pendulum, balance, or the like, e.g. putting into beat

Definitions

• Timepiece movement escapement, return member for timepiece escapements, timepiece movement and timepiece comprising such a movement
• the present invention relates to the field of watchmaking and in particular portable mechanical watchmaking. Its object is to replace the spiral spring as a return member of the balance wheel with a component that is simpler to manufacture, which does not have the defects of the balance spring and which can be adapted to existing escapement systems for portable timepieces.
• the present invention relates to a clock movement escapement, comprising a balance wheel, an escape wheel, an anchor and a balance return member. It also relates to a return member for a timepiece movement comprising an escapement provided with a balance wheel, an escape wheel and an anchor.
• the invention also relates to a timepiece movement comprising an escapement provided with a balance wheel, an escapement wheel, an anchor and a balance return member.
• this invention relates to a timepiece comprising a movement, an escapement or a return member as defined above.
• spiral spring is by far not as satisfactory as the force of gravity and its performance is by far not invariable.
• the most important defect is its variation in vertical position, as well as the variation of its couple between the contraction and the relaxation of turns, what in terms of trade is called ascending angle and descending angle.
• the watch movement includes a toothed rake acting on a balance wheel pinion.
• the rake has a split rod and pivots on an axis arranged at the end of the split rod opposite the teeth of the rake.
• the movement of the timepiece comprises an elastic blade fixed to a plate at one of its ends and provided with a lug near its other end.
• the pin is designed to slide in the slot of the split rod of the rake. This rake, the split rod and the elastic blade work together to form the balance return mechanism.
• the elastic blade must be capable of storing energy when it is deformed by the movement of the rake. It must then return this energy to move the rake in the opposite direction, beyond the dead point or the rest position of the rake.
• the maintenance of the movement and the compensation of friction is done by the cooperation between an impulse plane of the escape wheel and the lifting of the anchor.
• the embodiment described in the aforementioned patent presents several problems.
• the elastic blade and the split rod are not in the same plane.
• the ergot protrudes from the elastic blade so that it can be placed in the slot of the split rod.
• the displacement of the lug in the slot generates a torsion of the elastic blade as well as friction, which involves significant energy losses.
• the elastic blade must respond to two contradictory constraints.
• its stiffness must be great enough for a sufficient quantity of energy to be stored during its deformation under the effect of the movement of the pendulum and released when the elastic blade returns towards its rest position. This amount of energy must also compensate for the losses linked to the friction of the lug in the slot and to the twists of the elastic blade.
• the stiffness must be low enough so that the rake can move enough to allow an angular displacement of the pendulum of at least 300°.
• the movement cannot start. Indeed, the movement can only start if a lifting of the anchor has reached an impulse plane of the escape wheel. This is not possible if the elastic blade is too rigid.
• a typical spiral spring has between 12 and 15 coils.
• a watch case such as a typical wristwatch does not make it possible to house an elastic blade long enough to obtain a functional return member.
• the invention described in this patent CH 34983 sought to solve certain problems of the spiral springs by producing a symmetrical return member, which avoids the problems linked to the asymmetry of the spiral springs.
• the result obtained cannot be implemented in practice in a watch of the wristwatch type.
• Swiss patent application No. 19698 also describes, in one of the embodiments, a rake acting on a balance pinion.
• the rake is linked to an elastic rod, the deformation of which is supposed to allow rotation of the balance pinion.
• the object of this invention is to provide a return member which reacts in the same way in both directions of movement of the balance, which is not disturbed in the vertical positions and which is not as fragile and delicate in its handling as a spiral spring.
• a clockwork movement escapement as defined in the preamble and characterized in that the balance wheel is integral with a balance wheel pinion, and in that the balance wheel return member comprises a rack provided a toothed sector arranged to cooperate with the balance pinion, this rake comprising an axis allowing its rotation between two extreme positions, called working positions, separated by a rest position; this return member further comprising a return mechanism comprising two springs arranged to urge the rake towards its rest position.
• a return member as defined in the preamble and characterized in that it comprises a rake provided with a toothed sector arranged to cooperate with a balance wheel pinion, this rake comprising an axis allowing its rotation between two extreme positions, called working positions, separated by a rest position; and two springs arranged to urge the rake towards its rest position.
• the aims of the invention are further achieved by a timepiece movement as defined in the preamble and characterized in that the balance wheel is secured to a balance wheel pinion, and in that the balance wheel return member comprises a rake provided with a toothed sector arranged to cooperate with the pinion of the balance wheel, this rake comprising an axis allowing its rotation between two extreme positions, called working positions, separated by a rest position, this return member further comprising a return mechanism comprising two springs arranged to urge the rake towards its rest position.
• a timepiece comprising a movement, an escapement or a return member as defined above.
• the return member is not fixed to the balance and its connection with the balance is effected by mechanical gearing.
• This return member comprises a toothed part, hereinafter referred to as a rake, and a return mechanism comprising two springs made in the form of two elastic blades.
• the increase in friction due to the gearing between the rake and the pinion of the balance wheel is, according to the invention, compensated by the reduction in the disadvantages due to the spiral spring, its studding, its racking as well as the defects described at the beginning of this exposed.
• the escapement of the invention comprises a rack provided with a toothed sector cooperating with a pinion of the balance wheel. It also has a return mechanism with two elastic blades. The rake pivots on its axis between two extreme positions, called working positions and corresponding to the maximum rotation of the pendulum. These two extreme points are separated by a position of rest.
• the return member has symmetry with respect to a plane passing through an axis of rotation of the balance. Due to this symmetry, the forces acting when the balance wheel moves in one direction of rotation are the same as those acting when the balance wheel moves in the other direction of rotation.
• One of the drawbacks due to the asymmetry of the hairspring is thus eliminated.
• the return member of the invention is formed of a return mechanism comprising two springs made in the form of two elastic blades or spring blades acting on the rake. These elastic blades can be configured and placed in such a way that the rake can move slightly angularly before one of the elastic blades acts on it to bring it back to its rest position. This allows a start of the movement of the watch and avoids the problem of stopping on the rest plane.
• the fact of using two elastic blades independent of each other and never working simultaneously makes it possible to divide the stiffness of the return mechanism by two, which makes it possible to obtain blades of sufficiently short length to be able to be placed in a conventional size watch case. This makes it possible in particular to avoid the problems of the return members described in the patents CH 34983 and CH 19698.
• the two elastic blades are independent of each other. Therefore, when one of the blades is deformed so as to store energy or to restore it, the other elastic blade is inactive and does not interact with the rake. This avoids problems linked to elastic blades that are too rigid, which could arise in the case where two elastic blades act simultaneously on the rake.
• the rake is formed from a sector of a toothed wheel which could typically have between 80 and 160 teeth. Assuming that the balance performs a movement with an amplitude of 330° and that the balance wheel has 10 teeth, the angular displacement would be 37.125° for a rake corresponding to an 80-tooth wheel and 18.5625° for a corresponding rake to a 160-tooth wheel.
• the small angular displacement of the rake can be managed by the return mechanism while allowing a large angular displacement of the pendulum.
• Figure 1 is a top view of a classic Swiss lever escapement, without hairspring
• Figure 2 is a side view of the exhaust of Figure 1;
• Figure 3 is a profile view of the escapement of Figures 1 and 2, comprising a balance shaft fitted with a pinion;
• Figure 4 is a top view of part of the escapement of Figures 1 to 3, comprising a return member according to a first embodiment of the present invention, in a rest position;
• Figure 5 illustrates the return member of Figure 4, in a rest position
• Figure 6 illustrates the return member of Figure 4, in a working position
• Figure 7 is a top view of a variant of the return member of the invention, in a rest position
• Figure 7a is an enlarged view of part of Figure 7;
• Figure 8 is a top view of the return member of Figure 7, in a working position;
• Figure 9 illustrates a return member similar to that of Figure 6, in which an adjustment of the position of the elastic blades can be performed
• Figure 10 shows a variant of the return member according to the invention, in a rest position
• Figure 11 is a view of the return member of Figure 10, in a working position
• Figure 15 shows the return member of Figure 14, in the working position
• Figure 16 shows a return member with an internally toothed rake and a return mechanism identical to that of Figures 14 and 15.
• the invention relates in particular to a watch movement escapement.
• the escapement comprises a conventional part and a new part.
• the conventional part is represented in figures 1 to 3 by part of a Swiss lever escapement.
• This escapement comprises a balance 10 pivoting on a balance shaft 11, an anchor 12 pivoting on an axis of the anchor 13 and an escapement wheel 14 pivoting on an escapement wheel axis 15.
• the anchor 12 also comprises in a conventional manner, in particular a fork 16 actuated by the balance wheel 10 and two lifts 17 acting on teeth 18 of the escapement wheel 14.
• this escapement does not comprise a spiral spring.
• the Swiss lever escapement has been represented here, this escapement being the most commonly used in practice.
• a return member according to the invention could however also be used on any other escapement in which a balance wheel acts as a regulating member.
• the new part comprises a return member 19 replacing the spiral spring in its function.
• the return member according to the invention can be integrated into an existing escapement or form part of an escapement developed specifically for this movement.
• the balance 10 used in the present invention comprises a balance pinion 20 integral with the balance shaft 11.
• the return member 19 comprises a rake 21 comprising a toothed sector 22 and one or two arms 23.
• the rake 21 pivots around an axis of the rake 24 secured to a plate (not shown) of the movement of watchmaking. This rake can move on either side of its rest position, between two extreme working positions, in which the pendulum 10 has made a maximum movement, clockwise or anti-clockwise.
• the return member 19 further comprises a return mechanism 25 comprising two springs 26, the operation of which is described below. These springs 26 are formed of two elastic blades 27 in the illustrated embodiments.
• the rake 21 comprises two arms 23, one end of which is arranged at each end of the toothed sector 22 and the other ends of which meet close to the axis 24 of rotation of the rake .
• This rake 21 further comprises a rod 28 having one end close to the axis 24 of the rake and the other end integral with the elastic blades 27.
• the return member 19 can be placed on a plate of a timepiece which has two pins 30 arranged so that the elastic blades 27 can bear against these pins depending on the position of the rack 21 .
• the rake 21, the arms 23, the rod 28 and the elastic blades 27 are integral and are made in one piece.
• Figures 4 and 5 illustrate the rake 21 in the rest position.
• Figure 6 illustrates the rake 21 in the working position.
• the balance pinion 20 acts on the toothed sector 22 of the rake 21 to cause the latter to pivot in the opposite direction, on its axis of rotation 24.
• This has the effect of deforming one of the elastic blades 27 against the corresponding pin 30 of the movement.
• This elastic blade 27 stores energy.
• the other elastic blade is free and does not interact with the rest of the movement, nor with the other pin 30 so that it does not oppose the rotation of the rake 21 or the balance 10.
• the blade restores energy and causes the rake to pivot in the other direction of rotation.
• This causes the balance wheel to rotate via the balance pinion 20.
• the balance wheel 10 acts on the anchor 12 so as to release a tooth 18 from the escape wheel 14.
• An impulse plane d a tooth of the escapement wheel 14 acts on one of the lifts 17 of the anchor 12 so as to supply energy to this anchor which transmits it to the balance wheel 10 via the fork 16.
• This energy is used by the pendulum to pivot on its axis 11, which causes the rotation of the rake 21 on its axis 24 and makes it possible to load the other elastic blade 27 of the return mechanism 25.
• the pins 30 can be mounted on an eccentric and thus form an adjustment element 29.
• This eccentric makes it possible to modify the stiffness of the elastic blades 27 and consequently the amplitude of the rotation of the rake 21 and of the pendulum 10. More precisely, the two pins 30 of this adjustment element 29 can be moved, which makes it possible to adjust, within a certain margin, the distance between the elastic blade 27 and the axis of rotation 24 of the rake. This allows fine adjustment of the rate of the watch. This fine adjustment of the rate of the watch can also be done through a screw balance wheel, as shown in the various figures, or with flyweight balance wheels.
• the return mechanism 25 is separate from the rake 21 and is not integral with the latter.
• the rake 21 pivots on its axis of rotation 24 and comprises a single arm 23 connecting the toothed sector 22 of the rake to its axis of rotation 24.
• the return mechanism 25 also comprises two elastic blades 27, these blades being produced independently of the rake 21. These elastic blades are integral with a support 32 fixed to a plate of the movement of the timepiece. Each of the elastic blades 27 cooperates with one side of the arm 23 of the rake. When moving the rake in one direction, one of the elastic blades 27 presses against the corresponding side of the rake arm and deforms. This has the effect of allowing this elastic blade to store energy. The other elastic blade does not interact with the rake 21 so that only the stiffness of one blade and not of both intervenes.
• the elastic blade 27 restores energy and pushes the rake in the opposite direction, as explained above.
• the contact areas between the elastic blades 27 and the arm 23 of the rake can be polished so as to minimize friction.
• the rake 21 and the elastic blades 27 being arranged in the same plane, these elastic blades do not undergo torsion, but only a bending which makes it possible to store and restore energy.
• the elastic blades 27 are arranged on a movable support 33 whose position can be adjusted on the plate of the watch movement.
• This adjustment is possible by the fact that this mobile support 33 comprises a rack 34 and the plate comprises an adjustment pinion 35.
• the rotation of the adjustment pinion 35 has the effect of moving the rack 34 and therefore the position of the elastic blades 27.
• This makes it possible to modify the distance between the axis of rotation 24 of the rake and the points of contact between the elastic blades 27 and the arm 23 of the rake. This therefore modifies the force required to move the rake 21, which corresponds to an adjustment of the stiffness or the apparent stiffness of the elastic blades 27.
• Figures 10 and 11 illustrate a variant of the return member 19 according to the invention, in which the rake 21, the arm 23 of the rake and the elastic blades 27 of the return mechanism are made in one piece.
• the timepiece comprises two pins 30 arranged so that the elastic blades 27 can bear against them and be deformed so as to store and restore energy.
• the elastic strips 27 slide along the pins 30 and are not integral with them. There is thus a deformation in the form of bending of one blade at a time. There is neither simultaneous deformation of the two elastic blades, nor buckling, which would make the stiffness of the blades too great for real operation of the movement.
• Figure 10 illustrates the rake 21 in the rest position and Figure 11 illustrates the latter in the working position.
• Figure 11 illustrates the latter in the working position.
• only one blade at a time works to store and release energy. Indeed, only the elastic blade interacting with the pin 30 is active.
• the other elastic blade 27, shown on the left in Figure 11, does not interact with the corresponding pin 30 and therefore does not participate in the accumulation or the release of energy, in this phase of the movement of the rake.
• the rake 21 is similar to that of Figures 7 to 9.
• the elastic blades 27 of the return mechanism 25 are not rectilinear rods at rest, but form curves. An end zone of each of the elastic blades 27 bears against one side of the arm 23 of the rake 21 and operates according to the same principle as what has been explained with reference to Figures 7 to 9.
• This embodiment has the advantage of making it possible to increase the length of the elastic blades 27 and therefore consequently to reduce their stiffness, without however having to increase the size of the timepiece in which this return member will be housed.
• the blades illustrated in Figures 12 and 13 differ in their width and in the position of the contact between the elastic blades and the arm of the rake. The choice of the specific shape of the blades depends in particular on the space available in the movement.
• the elastic strips 27 form folds in the form of bellows.
• This embodiment is interesting because of the fact that it allows blades of great length to be produced, without requiring a large amount of available space in the case of the timepiece. As such, it approaches the length of the spiral springs, without however presenting the disadvantages.
• FIGS. 12 to 15 are also interesting because the position of the point of contact between the active spring blade 27 and the arm 23 of the rake moves with the movement of the rake 21 .
• Figures 14 and 15 which respectively represent the rake 21 in the rest position and in the working position
• the point of contact between one of the elastic blades 27 and the arm 23 of the rake is very close to the axis of rotation 24 of the rake. Therefore, the elastic blade 27 offers very little resistance to the rake 21, which allows a simple start of the movement, without risk of blocking.
• the shape of the elastic blades means that the point of contact between the active elastic blade 27 and the rake 21 moves in the direction of the toothed sector 22, opposite to the axis of rotation 24 of the rake.
• the force opposed by the elastic blade to the rake increases, which increases the energy that the elastic blade is able to store.
• the energy of the return mechanism 25 is not linear with respect to the movement of the rake 21, but is very low when the rake 21 is close to its rest position. This allows not only an easy start of the movement, but also an accumulation and an optimal return of energy.
• the rake 21 comprises internal teeth.
• the return mechanism 25 is identical to that of Figures 14 and 15. This is interesting in that part of the rake is located on the other side of the axis of the balance 11 with respect to the axis of rotation 24 of the rake. This saves space which can be useful in a small watch case and/or if the space dedicated to the escapement is limited.
• the movement of the timepiece comprises an adjustment element 29, such as the eccentric pins 30 illustrated in FIGS. 5 and 6, making it possible to position the elastic blades 27 in a suitable position, which can be adjusted and modified if necessary.
• a stress may begin to apply to the arm 23 of the rake 21 when the pendulum 10 is pivoted by approximately 10°.
• a rotation allows one of the anchor levers to be positioned on the impulse plane of one of the escapement teeth, which avoids blocking the movement and allows it to start.
• the rake 21 has been shown as having two arms 23 in Figures 4 to 6 and a single arm in the other figures. Forms of particular elastic blades have been shown for each embodiment. Combinations of the different embodiments are also possible. It is for example possible to use elastic blades as illustrated by figures 12 to 16, with a toothed rake with two arms as illustrated by figures 4 and 6.
• adjustment elements such as eccentrics or a mobile support can be added to the various embodiments illustrated.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Micromachines (AREA)
• Gears, Cams (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=77465976

Family Applications (1)

Country Status (6)

Family Cites Families (6)

• 2020
  • 2020-09-03 CH CH001090/2020A patent/CH717811B1/fr unknown
• 2021
  • 2021-08-10 JP JP2023515008A patent/JP2024500592A/ja active Pending
  • 2021-08-10 EP EP21759061.1A patent/EP4208759A1/de active Pending
  • 2021-08-10 WO PCT/EP2021/072227 patent/WO2022048864A1/fr unknown
  • 2021-08-10 CN CN202180054669.7A patent/CN116097178A/zh active Pending
  • 2021-08-10 US US18/043,642 patent/US20230324851A1/en active Pending

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