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
  • G04B17/32—Component parts or constructional details, e.g. collet, stud, virole or piton
  • G04B17/34—Component parts or constructional details, e.g. collet, stud, virole or piton for fastening the hairspring onto the balance
• • 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
  • G04B17/06—Oscillators with hairsprings, e.g. balance
  • G04B17/066—Manufacture of the spiral spring
• • 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
  • G04B17/32—Component parts or constructional details, e.g. collet, stud, virole or piton
  • G04B17/34—Component parts or constructional details, e.g. collet, stud, virole or piton for fastening the hairspring onto the balance
  • G04B17/345—Details of the spiral roll
• • G—PHYSICS
  • G04—HOROLOGY
  • G04D—APPARATUS OR TOOLS SPECIALLY DESIGNED FOR MAKING OR MAINTAINING CLOCKS OR WATCHES
  • G04D3/00—Watchmakers' or watch-repairers' machines or tools for working materials
  • G04D3/0002—Watchmakers' or watch-repairers' machines or tools for working materials for mechanical working other than with a lathe
  • G04D3/0035—Watchmakers' or watch-repairers' machines or tools for working materials for mechanical working other than with a lathe for components of the regulating mechanism
  • G04D3/0041—Watchmakers' or watch-repairers' machines or tools for working materials for mechanical working other than with a lathe for components of the regulating mechanism for coil-springs
• • G—PHYSICS
  • G04—HOROLOGY
  • G04D—APPARATUS OR TOOLS SPECIALLY DESIGNED FOR MAKING OR MAINTAINING CLOCKS OR WATCHES
  • G04D3/00—Watchmakers' or watch-repairers' machines or tools for working materials
  • G04D3/0069—Watchmakers' or watch-repairers' machines or tools for working materials for working with non-mechanical means, e.g. chemical, electrochemical, metallising, vapourising; with electron beams, laser beams

Definitions

• the subject of the present invention is a flat balance spring of a balance-spring balance obtained by a manufacturing process making it possible to improve the isochronism by acting on the one hand on parameters of construction of the balance spring as such, on the other hand on a method of attachment to the pendulum axis making it possible to reduce the geometric difference inherent in the usual methods of attachment between the point of origin of the Archimedes spiral and the axis of rotation of the pendulum.
• isochronism is understood to mean the deviations in speed as a function of variations in the amplitude of oscillation of the balance, as well as the deviations in speed between the horizontal position and the vertical positions of the watch.
• a hairspring having turns of uniform cross section and pitch, allows, by a particular conformation of the curve inside and the curve outside in the plane of the hairspring or more often in different planes , to obtain a concentric development of the hairspring and to have a displacement of the center of mass of the hairspring and a variation of the inertia of the hairspring during the development minimizing the walking disturbances as a function of the amplitude and the positions of the hairspring with respect to the gravity vector.
• the overall height constitutes a certain drawback for its use in wristwatches having to have, for obvious aesthetic reasons, the smallest possible thickness.
• a flat hairspring such as that shown in FIG. 1.
• Such a hairspring is manufactured in a known manner by stranding from a wire or a metal strip of constant section over its entire length, and has at rest a constant step between the turns. As can be seen in FIG. 1, the curve inside is fixed, for example by laser welding, to a ferrule 20, driven out on the axis 9 of a balance 8.
• patent CH 465,537 filed in 1966, in which is described a process making it possible to manufacture from a strip or of a metallic wire of constant section, wound in the groove of a matrix, then annealed and quenched, hairsprings having any configuration, in particular with a variable pitch.
• patent GB 1020 456 describes the production of a barrel spring by butt welds of blades having increasing sections from the center to the center. 'on the outskirts.
• Such a spring is designed, with equal dimensions, to increase the power reserve, but it is quite obvious that by applying this manufacturing process to a hairspring, the presence of welds would not allow to have a concentric development and obtain a reproducible isochronism from one hairspring to another.
• the subject of the invention is therefore a flat balance spring and methods of manufacture by micro-machining or galvanic growth, making it possible to conveniently choose the most favorable construction parameters in order to improve the isochronism by the shape of the balance spring as well. only by the fixing means.
• the invention relates to a flat hairspring, formed of a blade composed of a succession of turns having a pitch "p" between them, for a balance-regulating mechanism, said hairspring being obtained by a manufacturing process which allows to get closer to a perfect isochronism.
• the turns of rectangular section are formed in a single continuous material from the curve inside to the curve outside, but have, on certain portions between the fastener in the center and the fastener outside , a non-uniform section "s" and / or have one or more shaped portions outside the layout of a perfect spiral.
• non-uniform section means that, for a blade having a constant height "h", the thickness "e" of a chosen portion can be either greater or less than the thickness of the rest of the blade constituting the hairspring.
• the manufacturing process uses micro-techniques, such as photolithography and electrodeposition of a metal or an alloy, or micro-machining of a wafer.
• 'thickness "h” made of an amorphous or crystalline material such as silicon in monocrystalline or polycrystalline form.
• the section “s" of the turns gradually increases from the outside curve to the inside curve.
• the pitch "p" between the turns decreases regularly from the curve on the outside to the curve on the inside.
• the invention also offers the advantage of being able, at the same time as the hairspring as such, to manufacture the fixing means on the pendulum axis, this fixing means being formed by a self-locking washer having in the center, by example, a star contour and having recesses in its periphery to give it sufficient elasticity for mounting and avoid a gap between the point of origin of the Archimedes spiral and the axis of rotation of the pendulum.
• the manufacturing process basically involves applying the LIGA technique to form a mold corresponding to the profile desired by the hairspring. Given the properties of photoresists currently available on the market, it is possible to adjust the thickness of the photoresist layer to obtain the whole range of hairsprings with blade heights up to a few tenths of a millimeter.
• the method basically consists in etching a wafer of said material through masks.
• FIG. 2 is an enlarged representation of the hairspring of Figure 1;
• FIG. 3A corresponds to an isochronism diagram obtained with the hairspring shown in Figure 2;
• FIG. 4 shows a first embodiment of a hairspring according to the invention
• FIG. 5 corresponds to an isochronism diagram obtained with the hairspring of Figure 4;
• FIG. 6 represents a second embodiment of a hairspring according to the invention.
• FIG. 7 corresponds to an isochronism diagram obtained with the hairspring of Figure 6;
• - Figure 8 shows a third embodiment of a hairspring according to the invention;
• - Figure 10 shows a method of fixing a hairspring according to the invention
• - Figures 10A to 10E show other forms of fixing in the center.
• FIG. 1 shows a balance spring of the prior art mentioned in the preamble. Its characteristics will serve as a reference to show the significant progress made by the invention in isochronism.
• the hairspring 10 has the end of its curve at the center 11 conventionally fixed to a ferrule 20 driven out on the axis 9 of the pendulum 8 pivoted between the plate 7 and the cock 6.
• the regulating device further comprises, in a known manner, a piton holder 5 for fixing the curve outside 14 of the hairspring 10 and possibly a racket 4 provided with pins 3 and a racket tail 2 opposite a graduation 1.
• a piton holder 5 for fixing the curve outside 14 of the hairspring 10 and possibly a racket 4 provided with pins 3 and a racket tail 2 opposite a graduation 1.
• said hairspring is formed of 14 turns having a uniform rectangular section, for example 0.05 x 0.30 mm from the curve in the center 11 to the curve outside 14 , and that the turns have between them a constant pitch p_.
• the attachment point of the curve at the center 11 is located at a distance r from the pivot center of the balance spring, and that of the curve at the outside 14, at a distance R, before the bend 16.
• r and R are 0.57 mm and 2.46 mm respectively.
• FIG. 3A the isochronism diagram of a hairspring having the characteristics indicated above has been shown.
• the walking distance expressed in seconds per day has been reported.
• This diagram includes five curves corresponding to the usual positions for measurements with the balance spring, horizontal (curve 1), then vertical (curves 2 to 5, by rotation of 90 ° from one curve to another).
• the dotted line corresponds to the envelope of all the most unfavorable positions.
• the distance deviation is traditionally assessed by taking into consideration the maximum deviation of the envelope for an amplitude between 200 ° and 300 °. On the diagram of the FIG. 3A, it is observed that this maximum deviation, with this reference hairspring of the prior art, is 4.7 s / d for an amplitude of 236 °.
• FIG. 3B shows the diagram obtained with a hairspring (not shown) having the characteristics mentioned in US patent 209642 cited in the preamble, namely with a blade thickness varying between 0.046 mm for the curve outside 14 and 0.036 mm for the curve inside 11. Contrary to what can be expected from the teaching of said patent, it will be observed that the maximum difference has increased to 7.7 s / d for an amplitude of 230 °.
• FIGS. 4 and 5 a first embodiment of a hairspring is described below, the manufacture of which by micromachining
• the step p_ between one turn and the next decreases as and We get closer to the center of the hairspring.
• the section increases from the outside curve 14 to the inside curve 11. Since the manufacturing processes give the blade a constant height, the variation in section corresponds in fact to a variant of the thickness which goes from 0.036 mm for the curve outside 14 to 0.046 mm for the curve inside 11.
• Figures 6 and 7 correspond to a second embodiment of the "Michel" type for the curve outside 14 and for the curve inside 11.
• the turns have between them a constant pitch and a constant section corresponding to a constant thickness of 0.042 mm, with the exception of two portions of turns for which the thickness is increased to 0.056 mm:
• FIGS. 8 and 9 correspond to a third embodiment in which the curve inside 11 is of the Grossmann 13 type, that is to say having a geometry such as that described in the book "General theory of horology "by L. Defossez. Such geometry is very difficult to obtain by deformation of a metal strip.
• the manufacturing method according to the invention makes it very easy to obtain such a configuration without the intervention of highly qualified personnel.
• the diagram shown in Figure 9 shows that the maximum deviation at 300 ° is only 2.1 s / d.
• FIGS. 10A to 10E show other possible conformations of the self-locking washer 17 with a locking contour 19 in a triangle, square, hexagonal, circular or ogive shape.
• the hairspring-self-locking washer assembly is made by photolithography and galvanic growth, it is advantageous, by means of an additional step, to make said self-locking washer 17 with a thickness greater than the height of the blade in order to obtain better resistance of the hairspring. 10 on axis 9 of the pendulum.
• a hairspring according to the invention in an amorphous or crystalline material such as silicon can be manufactured by adapting the micromachining methods already used for example for the manufacture of integrated circuits or accelerometers from a silicon wafer.
• the process basically consists of the following steps:
• a hairspring according to the invention in metal or alloy, use is made of the LIGA technique known since the mid-70s.
• the process basically consists in spreading on a substrate previously coated with a sacrificial layer a positive or negative photoresist on a thickness corresponding to the desired height "h" of the slide and form, by means of a mask by photolithography and chemical attack, a hollow structure corresponding to the desired contour for the hairspring.
• said hollow structure is filled with a metal or a metal alloy either by electrodeposition as indicated for example in US Pat. No. 4,661,212, or by compression and sintering of nanoparticles, as indicated for example in US patent application 2001/0038803.
• the balance spring is released from the substrate by elimination of the sacrificial layer.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Optics & Photonics (AREA)
• Plasma & Fusion (AREA)
• Manufacturing & Machinery (AREA)
• Springs (AREA)
• Micromachines (AREA)
• Control Of Motors That Do Not Use Commutators (AREA)
• Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
• Pivots And Pivotal Connections (AREA)
• Vehicle Body Suspensions (AREA)
• Nonmetallic Welding Materials (AREA)

Priority Applications (3)

Applications Claiming Priority (4)

Related Child Applications (4)

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ID=32605375

Family Applications (4)

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Cited By (5)

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Family Cites Families (52)

• 2003
  • 2003-02-06 EP EP03075362A patent/EP1445670A1/de not_active Withdrawn
• 2004
  • 2004-02-02 KR KR1020057014243A patent/KR20050098881A/ko not_active Ceased
  • 2004-02-02 DE DE602004029762T patent/DE602004029762D1/de not_active Expired - Lifetime
  • 2004-02-02 AT AT04707219T patent/ATE486304T1/de not_active IP Right Cessation
  • 2004-02-02 EP EP04707219A patent/EP1593004B1/de not_active Expired - Lifetime
  • 2004-02-02 EP EP10151818.1A patent/EP2175328B1/de not_active Expired - Lifetime
  • 2004-02-02 EP EP06003086A patent/EP1655642B1/de not_active Expired - Lifetime
  • 2004-02-02 JP JP2005518308A patent/JP5122073B2/ja not_active Expired - Fee Related
  • 2004-02-02 DE DE602004023518T patent/DE602004023518D1/de not_active Expired - Lifetime
  • 2004-02-02 US US10/544,644 patent/US20060055097A1/en not_active Abandoned
  • 2004-02-02 CN CNB2004800033870A patent/CN100435044C/zh not_active Expired - Lifetime
  • 2004-02-02 WO PCT/EP2004/000931 patent/WO2004070476A2/fr not_active Ceased
  • 2004-02-04 TW TW093102542A patent/TW200426547A/zh unknown
• 2012
  • 2012-09-14 JP JP2012202260A patent/JP5389999B2/ja not_active Expired - Fee Related
• 2015
  • 2015-04-08 US US14/681,535 patent/US20150277382A1/en not_active Abandoned
• 2018
  • 2018-12-05 US US16/210,811 patent/US10444706B2/en active Active

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