The invention relates to timepiece mechanisms, to timepiece movements and timepieces having such mechanisms.
Usual timepiece movements are very complicated mechanisms which include a large number of moving parts, which makes such mechanisms costly, energy consuming because of friction undergone by moving parts. Further, these usual mechanisms are relatively bulky because they are constituted by a stack of different timepiece mechanisms, usually at least mainspring, transmission, escapement mechanism and regulator.
Document US2013176829A1 proposed a monolithic timepiece mechanism made in a single plate of material, comprising a frame, a first elastic suspension and an inertial regulating member which is connected to the frame by said first elastic suspension so as to be able to oscillate.
Thus, this document tried to propose a solution for limiting the number of parts moving with friction; however, the problem of thickness of the timepiece movement remains.
One objective of the present invention is to further limit cost and energy losses in a time piece, and to limit thickness thereof.
To this end, according to an embodiment of the invention, the monolithic timepiece mechanism further includes a blocking mechanism having at least a blocking member connected to the frame by a second elastic suspension, said blocking member being controlled by the regulating member to be able to regularly and alternatively hold and release a movable energy distribution member so that said energy distribution member moves by steps, of a constant angular travel at each rotational step, said blocking mechanism being further adapted to regularly transmit energy from the energy distribution member to the regulating member for maintaining oscillation of said regulating member.
Thanks to these dispositions, the same plate of material includes both functions of the regulator and the escapement mechanism, which lowers costs and limits frictional losses. Further, the invention enables to cancel one layer of mechanism compared to the classical timepiece movements, this limiting the thickness of the timepiece movement.
In various embodiments of the monolithic timepiece mechanism according to the invention, one may possibly have recourse in addition to one and/or other of the following arrangements:
Besides, the invention also concerns a timepiece movement having a monolithic timepiece mechanism as described above and an energy distribution member cooperating with said blocking member so that said blocking member may regularly and alternatively hold and release said energy distribution wheel, and said energy distribution member may regularly release energy to the regulating member through the blocking member for maintaining oscillation of said regulating member.
In various embodiments of the timepiece movement according to the invention, one may possibly have recourse in addition to one and/or other of the following arrangements:
Further, the invention also concerns a timepiece having a timepiece movement as defined above.
Other features and advantages of the invention appear from the following detailed description of one embodiment thereof, given by way of non-limiting example, and with reference to the accompanying drawings.
In the drawings:
a to 9,9a are views similar to
In the Figures, the same references denote identical or similar elements.
The energy distribution member may be a rotary energy distribution wheel 5. The following description will be made with respect to such energy distribution wheel.
The mechanical energy storage 2 is usually a spring, for instance a spiral shaped spring usually called mainspring. This spring may be wound manually through a winding stem and/or automatically through an automatic winding powered by the movements of the user.
The transmission 3 is usually a gear comprising a series of gear wheels (not shown) meshing with one another and connecting an input shaft to an output shaft (not shown). The input shaft is powered by the mechanical energy storage 2 and the output shaft is connected to the energy distribution wheel. Some of the gear wheels are connected to the watch hands or other time indicators 4.
The transmission 3 is designed so that the energy distribution wheel rotates much more quickly than the input shaft (with a speed ratio which may be for instance of the order of 3000).
The regulator mechanism 7 is designed to oscillate with a constant frequency, thus ensuring the timepiece's precision. The oscillation of the regulator is sustained by regular transfers of mechanical energy from the energy distribution wheel 5, through a monostable elastic member 9 which may for instance belong to the blocking mechanism 6.
The mechanical energy storage 2, transmission 3, energy distribution wheel 5, blocking mechanism 6 and regulator 7 form together a timepiece movement 10.
The particular embodiment of
In this embodiment, the blocking mechanism 6 and regulator mechanism 7 may be monolithic and made in a single plate 11, as shown for instance in
The plate 11 may have a small thickness, e.g. about 0.1 to about 0.6 mm, depending of the material thereof.
The plate 11 may have transversal dimensions, in the plane of said plate (e.g. width and length, or diameter), comprised between about 15 mm and 40 mm.
The plate 11 may be manufactured in any suitable material, preferably having a relatively high Young modulus to exhibit good elastic properties. Examples of materials usable for plate 11 are: silicon, nickel, steel, titanium. In the case of silicon, the thickness of plate 11 may be for instance comprised between 0.3 and 0.6 mm.
The various members of the blocking mechanism 6 and regulator mechanism 7, which will be detailed hereafter, are formed by making cutouts in plate 11. These cutouts may be formed by any manufacturing method known in micromechanics, in particular for the manufacture of MEMS.
In the case of a silicon plate 11, plate 11 may be locally hollowed out for instance by Deep Reactive Ion Etching (DRIE), or in some cases by solid state laser cutting (in particular for prototyping or small series).
In the case of a nickel plate 11, the blocking mechanism 6 and regulator mechanism 7 may be obtained for instance by LIGA.
In the case of a steel or titanium plate 11, plate 11 may be locally hollowed out for instance by Wire Electric Discharge Machining (WEDM).
The constituting parts of the blocking mechanism 6 and regulator mechanism 7, each formed by portions of plate 11, by will now be described in details. Some of these parts are rigid and others are elastically deformable, usually in flexion. The difference between so-called rigid parts and so-called elastic parts is their rigidity in the plane of plate 11, due to their shape and in particular to their slenderness. Slenderness may be measured for instance by the slenderness ratio (ratio of length of the part on width of the part). Parts of high slenderness are elastic (i.e. elastically deformable) and parts of low slenderness are rigid. For instance, so-called rigid parts may have a rigidity in the plane of plate 11, which is at least about 1000 times higher than the rigidity of so-called elastic parts in the plane of plate 11. Typical dimensions for the elastic connections, e.g. elastic branches 21, 33 and elastic links 27 described below, include a length comprised for instance between 5 and 13 mm, and a width comprised for instance between 0.01 mm (10 μm) and 0.04 mm (40 μm), e.g. around 0.025 mm (25 μm).
Plate 11 forms an outer frame which is fixed to a support plate 11a for instance by screws or similar through holes 11b of the plate 11. The support plate 11a is in turn fixed in the timepiece casing.
In the example shown on
The energy distribution wheel 5 is pivotally mounted relative to the support, around an axis of rotation Z which is perpendicular to the plate 11. The energy distribution wheel 5 is biased by energy storage 2 through transmission 3 in a single direction of rotation 36.
The energy distribution wheel 5 has external teeth 5a, each having a front face 5b facing the direction of rotation 36 and a rear face 5c opposite the direction of rotation 36.
For instance, the front face 5b can extend in a radial plane which is parallel to the rotation axis Z, while the rear face 5c may extend parallel to axis Z and slantwise relative to the radial direction (see
It should be noted that the teeth 5a do not need to have the complex shape of a classical escapement wheel of a so-called Swiss-lever escapement or Swiss-anchor escapement.
The monostable elastic member 9 is linked to the regulator mechanism 7 and is adapted to bear on the teeth 5a of the energy distribution wheel 5. The monostable elastic member 9 normally have a first geometrical configuration (rest position) and the teeth 5a of the energy distribution wheel are adapted to elastically deform said monostable elastic member 9 by cam effect from said first geometrical configuration to a second geometrical configuration. The monostable elastic member 9 is arranged such that during each rotation cycle of the energy distribution wheel 5:
The regulator mechanism may have a rigid, inertial regulating member 17 which is connected to the frame of the plate 11 by a first elastic suspension 21. The first elastic suspension may comprise for instance two flexible, first elastic branches 21 extending substantially parallel to the second direction Y, from the side 12 of the plate 11 so that the regulating member 17 is movable in translation substantially parallel to the first direction X with respect to the support. The regulating member 17 and the first elastic suspension 21 are arranged so that said regulating member 17 oscillates in two directions from the neutral position shown on
The translation movement of regulating member 17 may be substantially rectilinear.
Advantageously, the regulating member 17 is mounted on the support to oscillate in circular translation, with a first amplitude of oscillation in the first direction X and a non-zero, second amplitude of oscillation in the second direction Y. Preferably, the first amplitude of oscillation is at least 10 times the second amplitude, which makes the movement substantially rectilinear.
The regulating member 17 may have a main rigid body 18 extending longitudinally substantially parallel to the first direction X close to the side 12 of plate 11, two diverging rigid arms 19 extending from the ends of the main body 18 toward the side 15 of plate 11, up to respective free ends 20. The free ends 20 may extend outwardly opposite to each other, substantially parallel to the first direction X.
The first elastic branches 21 may have first ends connected to the side 12 of plate 11, respectively close to sides 13, 14 of plate 11, and second ends respectively connected to the free ends 20 of the arms 19. The first elastic branches 21 may be substantially rectilinear (i.e. not flexed) when the regulating member 17 is at rest in the neutral position.
The length of first elastic branches 21 and the amplitude of oscillation of regulating member 17 are such that the movement of said regulating member 17 is substantially rectilinear, as explained above.
The blocking mechanism 6 has a rigid blocking member 8 which is connected to the regulating member 17 by at least an elastic link 27 so as to move in synchronism with said regulating member 17.
In the example shown on
The blocking member 8 may be mounted on the frame of the plate 11 by a second elastic suspension 33. The second elastic suspension 33 may be arranged to impose a translational movement to the blocking member 8 in the second direction Y. The second elastic suspension may comprise two flexible, second elastic branches 33 extending substantially parallel to the first direction X, so that blocking member 8 is movable in translation substantially parallel to the first direction X, in direction of double arrows 8a. The blocking member is thus movable in two opposite directions from a neutral position, between two extreme positions called here “first and second extreme blocking member positions”. The elastic branches 33 may be arranged so as to be substantially linear (not flexed) when the blocking member 8 is at rest in the neutral position.
In the example shown on
The elastic links 27 may have first ends connected to main body of regulating member 18, close to the ends thereof, and second ends respectively connected to the free ends 24, 26 of the arms 23, 25.
Besides, the free end 26 of the lateral arm 25 may be extended toward the other lateral arm 23, in the first direction X, by a first transversal, rigid arm 30. The lateral arm 25 may also be extended, toward the other lateral arm 23, in the first direction X, by a second rigid transversal arm 28 which is close to the base 22. The energy distribution wheel 5 is between first and second transversal arms 30, 28.
The respective free ends of the first and second transversal arms 30, 28 may have respectively first and second stop members 29a, 29b. First and second stop members 29a, 29b may be in the form of rigid fingers protruding toward each other from the free ends of first and second transversal arms 30, 28, in the second direction Y.
First and second stop members 29a, 29b are designed to cooperate with the teeth 5a of the energy distribution wheel 5, as will be explained in more details below, to alternately hold and release said energy distribution wheel 5. First and second stop members 29a, 29b may have a stop face, respectively 29a1, 29b1, facing the front face 5b of the teeth, and an opposite rear face, respectively 29a2, 29b2. The stop faces 29a1, 29b1 may preferably be disposed in a radial plane parallel to axis Z, while the rear faces 29a2, 29b2 may extend slantwise so that the stop members 29a, 29b have pointed shapes.
Blocking member 8 may further include a strut 25 a, extending in the second direction Y and joining the lateral arm 25 to the first transversal arm 30.
Blocking member 8 may further have a tab 31 extending in the second direction Y from the transversal arm 30, toward the side 15 of plate 11.
The free end 26 and first transversal arm 30 may be received with small play in an indent 26a cut out in the side 25 of plate 11. In addition, tab 31 may be received in a further indent 31a cut out in the side 15 of plate 11.
Plate 11 may further include a rigid tongue 16, extending in the second direction Y from the side 15 of plate 11 toward side 12, between the energy distribution wheel 5 and the lateral arm 23 of the blocking member 8. Tongue 16 may have a first edge 16a facing the energy distribution wheel 5 and extending parallel to the second direction Y. The first edge 16a may have a concave, circular cut out 16b partly receiving the energy distribution wheel 5. Tongue 16 further has a second edge 16c opposite the first edge and facing the lateral arm 23. The second edge 16c may be slanted parallel to the lateral arm 23, and be in close vicinity to lateral arm 23.
One of the second elastic branches 33 may have a first end connected to the first edge 16a of the tongue 16, close to the side 15 of plate 11, and a second end connected to the tab 31. The other of the second elastic branches 33 may have a first end connected to the first edge 16a of the tongue 16, close to the free end of the tongue 16, and a second end connected to the lateral arm 25 close to the base 22.
The blocking member 8 may be connected to the monostable elastic member 9. In particular, said monostable elastic member may be a flexible tongue 9 which has a first end connected to the blocking member 8 (and therefore linked to the regulator mechanism 7 through flexible links 27) and a second, free end bearing on the teeth 5a of the energy distribution wheel 5. Typical dimensions for the flexible tongue 9 include a length comprised between for instance 3 and 5 mm, and a width comprised for instance between 0.01 mm (10 μm) and 0.04 mm (40 μm), for instance around 0.025 mm (25 μm).
The flexible tongue 9 may be mounted on the blocking member 8 adjacent the second stop member 29b. In particular, the flexible tongue may be connected to the lateral arm 25 of the blocking member 8, close to the transversal arm 28. The flexible tongue 9 may extend substantially parallel to the first direction X, between the transversal arm 28 and the energy distribution wheel 5, up to a free end which is close to the second stop member 29b.
The flexible tongue 9 and blocking member 8 being two distinct members, the mechanism thus provides a separation between the function of blocking/releasing the distribution wheel 5 (provided by the blocking member 8) and the function of transferring energy to the regulator mechanism to sustain oscillation thereof (provided by the flexible tongue 9). Thanks to this separation of functions, the design of the blocking member 8 doesn't need to take into account the function of transferring energy (as it is the case in a traditional Swiss-anchor escapement which handles both blocking and energy transferring functions) and the design of the flexible tongue 9 doesn't need to take into account the function of blocking/releasing the distribution wheel 5.
During operation, regulating member oscillates in translation parallel to the first direction X, with a frequency f comprised for instance between 20 and 30 Hz, and blocking member 8 oscillates with a frequency 2f, twice the oscillation frequency of the regulating member 17.
More precisely, the elastic links 27 are arranged such that:
During this movement, the first and second stop members 29a, 29b move substantially radially with regard to the energy distribution wheel 5, alternately toward and away from said energy distribution wheel, and the first and second stop members 29a, 29b thus interfere in turn with the teeth 5a of the energy distribution wheel 5 so as to hold said energy distribution wheel 5 respectively when said blocking member 8 is in the first and second extreme blocking member positions.
More precisely, the first stop member 29a is arranged to:
Besides, the second stop member 29b is arranged to:
Further, the second escape position of blocking member 8 may be between the first extreme blocking member position (close to side 12) and the first escape position. In that case, advantageously, the first and second stop members 29a, 29b are arranged such that:
The flexible tongue 9 may be arranged such that the teeth 5a of the energy distribution wheel 5 elastically deform said monostable elastic member 9 from said first geometrical configuration to said second geometrical configuration during rotation of the energy distribution wheel 5 when the blocking member 8 is between the first escape position and the second extreme blocking member position. Thus, the flexible tongue 9 accumulates a predetermined potential mechanical energy, corresponding to the geometrical deformation thereof between the predetermined first geometrical configuration and the predetermined second geometrical configuration. This predetermined energy is the same at each rotation cycle of the energy distribution wheel 5.
The flexible tongue 9 may be arranged such that said flexible tongue 9 is in the second geometrical configuration when the blocking member 8 is in the second extreme blocking member position. Thus, the flexible tongue 9 returns to the first geometric configuration and transfers said predetermined amount of mechanical energy to the blocking member 8 during movement of the blocking member 8 from the second extreme blocking member position to the second escape position. The elastic links 27 are arranged to transmit said predetermined amount of mechanical energy to the regulating member 17.
Further, the flexible tongue 9 may be arranged not to interfere with the teeth 5a of the energy distribution wheel 5 while the blocking member 8 moves from the second escape position to the first extreme blocking member position and from said first extreme blocking member position to the first escape position.
Preferably, the transmission 3 is such that each rotation step of the energy distribution wheel 5 is completed in a time which is not longer than the time necessary for the blocking member 8 to travel from the first escape position to the second extreme blocking member position.
The operation of the mechanism will now be described step by step, with regard to
In the position of
For a better understanding, reference numerals have been given to some of the teeth 5a on
The mechanism then arrives in the position of
The regulating member 17 and blocking member 8 then change their direction of movement, and the mechanism arrives in the position of
The energy distribution wheel 5 then quickly turns of one angular step and the mechanism arrives in the position of
The mechanism then arrives in the position of
The mechanism then arrives in the position of
After the energy distribution wheel has turned of one angular step, the mechanism then arrives in the position of
The regulating member 17 and blocking member 8 then change direction and the same steps occur until the mechanism reaches back the position of
Thus, the movement cycle of energy distribution wheel 5 includes two angular steps of rotation, each equivalent to half the angular extent of one tooth 5a. In the example of
The invention is not limited to translational movements of the regulating member 17 and blocking member 8; in particular, the first elastic suspension 21 may be arranged to impose either a translational movement, or a rotational movement to the regulating member 17, and the second elastic suspension 33 may be arranged to impose either a translational movement, or a rotational movement to the blocking member 8.
Three variants are shown in
In the variant of
Regulating member 117 may have a central hub 117 connected to the frame of the plate 11 by the first suspension 121. First suspension 121 may have two elastic branches 121 disposed radially relative to the axis of rotation Z″.
Regulating member 117 may also have a plurality of rigid arms 117b extending radially from the hub 117a, for instance two arms 117b.
The blocking member may have first and second arms 108a, 108b forming an angle together, each having a stop member 129a, 129b adapted to interfere with the energy distribution wheel 5. The axis of rotation Z′ may be at the apex between arms 108a, 108b. The arm 108b may support the monostable elastic member 9, for instance an elastic tongue 9 extending from the free end of the arm 108b up to a free end close to the stop member 129b.
The blocking member 108 is connected to the frame of the plate 11 by a second suspension 133, for instance by two elastic branches 133 disposed radially with regard to the axis of rotation Z′.
The blocking member 108 may have a third rigid arm 108c, disposed radially with respect to the axis of rotation Z′ and connected to the hub 117a of the regulating member by an elastic link 127.
When regulating member 117 oscillates around axis Z″ in the direction of double arrow 117c, the elastic link 127 controls oscillation of blocking member 108 around axis Z′ according to the double arrow 108d, so that stop members 129a, 129b alternately hold and release energy distribution wheel 5. During each rotation of energy distribution wheel 5, one of the teeth 5a of the energy distribution wheel 5 flexes the elastic tongue 9, which then releases its mechanical energy to the blocking member 108 and the regulating member 117.
The variant of
In the variant of
Regulating member 217 may have a central hub 217 connected to the frame of the plate 11 by the first suspension 221. First suspension 221 may have two elastic branches 221 disposed radially relative to the axis of rotation Z″.
Regulating member 217 may also have a plurality of rigid arms 217b extending radially from the hub 217a, for instance two arms 217b.
The blocking member 208 may have a rigid body 208a extending longitudinally in the second direction Y and two transversal arms 208b, 208c extending from the body 208a parallel to the first direction X on both sides of energy distribution wheel 5, each transversal arm having a stop member 229a, 2209b adapted to hold and release the energy distribution wheel 5 as in the embodiment of
The body 208a of the blocking member may be connected to the frame of the plate 11 by a second suspension 233, comprising for instance two second elastic branches 233 parallel to the first direction X.
The blocking member 208 also includes an elastic tongue 9, extending from the body 208a substantially parallel to the first direction X, up to a free end close to stop member 229b.
The blocking member 208 may further include an additional arm 208d, extending opposite the transversal arms from the body 208a and connected to the hub 217a of the regulating member by an elastic link 227.
When regulating member 217 oscillates around axis Z″ in the direction of double arrow 217c, the elastic link 227 controls oscillation of blocking member 208 in the second direction Y according to the double arrow 208e, so that stop members 229a, 229b alternately hold and release energy distribution wheel 5. During each rotation of energy distribution wheel 5, one of the teeth 5a of the energy distribution wheel 5 flexes the elastic tongue 9, which then releases its mechanical energy to the blocking member 208 and the regulating member 217.
The variant of
In the variant of
Regulating member 317 may have main body 318, two lateral arms 319 and free ends 320 which are similar to parts 18, 19, 20 of the embodiment of
When regulating member 317 oscillates in the direction of arrows 217a, the elastic link 327 controls oscillation of blocking member 108 around axis Z′ according to the double arrow 108d, so that stop members 129a, 129b alternately hold and release energy distribution wheel 5. During each rotation of energy distribution wheel 5, one of the teeth 5a of the energy distribution wheel 5 flexes the elastic tongue 9, which then releases its mechanical energy to the blocking member 108 and the regulating member 117.
The variant of
Number | Date | Country | Kind |
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14197017.8 | Dec 2014 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2015/078865 | 12/7/2015 | WO | 00 |