EP3451076A1 - Stud-holder for a mechanical clockwork movement - Google Patents

Abstract

The invention relates to a bolt carrier (29) for a mechanical clockwork movement (5), which comprises a pair of legs, namely a front tab (31) and a rear tab (32), together defining a notch (33), the tabs (32, 33) being arranged so that a pin (35) can be maintained in the notch (33), characterized in that the lug (32) back of the bolt carrier (29) comprises an extension (56) which defines, beyond the notch (33), an elbow (57) forming a retaining stop for the stud (35) when said stud (35) is extracted from the notch (33).

Description

Technical area

The invention relates to the field of watchmaking, and more particularly to the field of mechanical watchmaking, where the regulation of the motive power is provided by a spring oscillator. The invention relates, more specifically, a bolt carrier for a mechanical movement.

Technological background

In most mechanical watches, the energy required for the rotation of the hands (eg indicator hands of the minutes and hours) is accumulated and then dispensed by a balance-balance system, which includes a wheel of inertia called balance wheel, associated with a spring in the form of a ribbon wound spirally, called spiral.

By an inner end, the hairspring is fixed on a shaft integral in rotation with the balance; by an external end, the hairspring is fixed on a peg mounted on a peg holder itself secured to a bridge (or cock) fixed.

Traditionally, the spiral is made of a steel alloy based on cobalt, nickel and chromium. Quenching and tempering are commonly applied to this alloy, which has the advantage of giving it a high yield strength and therefore good breaking strength. Another advantage of steel is its ability to repair. But a disadvantage of steel is its magnetisable nature, which affects its behavior in charge (and therefore to the precision of the watch movement); in addition, fixing the stud by gluing is difficult on steel.

It is also known (although less common) to use, for the manufacture of the spiral, silicon. According to Vermot et al (Treaty of Watchmaking Construction, Presses Techniques et Universitaires Romandes, 2014, pp.712-713 ), the silicon has the advantage of having a low moment of inertia, a low coefficient of expansion, a good resistance to corrosion and to be non-magnetic. In addition, it is possible to fix the stud at the outer end of the silicon spring by means of an ultraviolet-activated two-component glue, which offers a very high fixing power. However, the main disadvantage of silicon is its brittle nature, under the conditions described below.

The rotation of the balance is maintained - and its oscillations counted - by an escape mechanism comprising an anchor animated with a small amplitude oscillating movement, provided with two pallets which attack the teeth of an escape wheel. Thus attacked, the escape wheel is imposed a rotational movement step by step whose frequency is determined by the frequency of oscillation of the anchor, itself set to the oscillation frequency of the balance (c that is, the hairspring).

In a traditional exhaust mechanism, the oscillation frequency is about 4 Hz, or about 28,800 vibrations per hour (Ah). A goal of good watchmakers is to ensure the isochronism and regularity of oscillations (or constancy of walking) of the pendulum.

It is known to adjust the step of the balance by adjusting the active length of the spiral, defined as the curvilinear length between its inner end and a counting point, located in the vicinity of the outer end of the hairspring and generally defined by a pair of stops carried by a key mounted on a racket.

In operation, this racket is fixed in rotation relative to the axis of the spiral. However, it is possible, by manual intervention, to finely adjust the angular position, e.g. by pivoting, by means of a screwdriver, an eccentric acting on the racket in the manner of a cam.

The assembly comprising the bridge, the racket, the key, the stud, the stud, the axle, the spring and the balance, is commonly referred to as "regulating organ". Examples of regulating organs are proposed by the international application WO 2016/192957 and by the European patent EP 2 876 504 , both in the name of the watch manufacturer ETA.

Some interventions on the regulating organ may require unwinding (or even complete disassembly) of the spiral. It is then necessary to dissociate the pin, secured to the outer end of the hairspring, the bolt carrier.

This operation, called "viciousness," is delicate. The watchmaker usually picks up the stud with a pair of tweezers, and then gently removes it from the stud holder.

However, it often happens that the piton escapes the tweezers, which causes a sudden relaxation of the hairspring, the outer end of which is released.

This incident is of no consequence when the hairspring is made of steel (and more precisely alloy steel, as indicated above), because quenching and tempering treatments which are applied make it sufficiently ductile to allow rewinding of the hairspring.

On the other hand, this same incident is dramatic for a silicon spiral which, statistically, breaks in more than one case out of two.

The object of the invention is to allow a mastication by limiting or even eliminating the risk of breakage.

Summary of the invention

It is proposed, in the first place, a bolt carrier as defined in claim 1.

In this way, the piton extracted from the notch is wedged in the abutment, which prevents the spring (spiral) to relax suddenly during the buckle. The risk of breakage of the spring is thus limited.

Advantageous features of the bolt carrier, which can be taken alone or in any technically possible combination, are defined in the dependent claims.

It is proposed, secondly, a set comprising such a peg carrier.

Advantageous features of the assembly, which may be taken alone or in any technically possible combination, are defined in the dependent claims.

Thirdly, a watch movement comprising such a set is proposed.

Fourth is a watch comprising such a mechanical clockwork movement.

Brief description of the figures

• La FIG.1 est une vue en perspective éclatée montrant partiellement une montre comprenant un mouvement d'horlogerie mécanique incluant un organe réglant ;
• La FIG.2 est une vue en perspective de dessus montrant l'organe réglant seul ;
• La FIG.3 est une vue en perspective de dessous montrant l'organe réglant ;
• La FIG.4 est une vue en perspective éclatée, de dessus, de l'organe réglant ;
• La FIG.5 est une vue en perspective éclatée, de dessous, de l'organe réglant ;
• La FIG.6 est une vue en perspective du porte-piton équipant l'organe réglant des figures précédentes ;
• La FIG.7 est une vue en perspective partielle montrant le porte-piton, le piton (en pointillés) monté sur le porte-piton, et une partie du brin externe du ressort (également en pointillés) ;
• La FIG.8 est une vue en perspective similaire à la FIG.7, montrant le porte-piton avec le piton extrait de l'encoche et en butée contre le coude ;
• La FIG.9 est une vue de dessous du porte-piton seul ;
• La FIG.10 est une vue de dessous du porte-piton avec, en pointillés, le piton encliqueté dans l'encoche et, en trait plein, le piton extrait de l'encoche, en butée contre le coude.

Other objects and advantages of the invention will become apparent in the light of the description of an embodiment, given hereinafter with reference to the accompanying drawings, in which:

• The FIG.1 is an exploded perspective view partially showing a watch comprising a mechanical clockwork including a regulating member;
• The FIG.2 is a perspective view from above showing the regulating organ alone;
• The FIG.3 is a perspective view from below showing the regulating organ;
• The FIG.4 is an exploded perspective view, from above, of the regulating organ;
• The FIG.5 is an exploded perspective view, from below, of the regulating organ;
• The FIG.6 is a perspective view of the bolt carrier equipping the regulating member of the preceding figures;
• The FIG.7 is a partial perspective view showing the bolt carrier, the bolt (dashed) mounted on the bolt carrier, and a portion of the outer strand of the spring (also dashed);
• The FIG.8 is a perspective view similar to the FIG.7 , showing the peg carrier with the peg extracted from the notch and in abutment against the elbow;
• The FIG.9 is a view from below of the lug carrier alone;
• The FIG.10 is a bottom view of the bolt carrier with, in dotted lines, the bolt snapped into the notch and, in solid lines, the bolt extracted from the notch, in abutment against the elbow.

Detailed description of the invention

On the FIG.1 is represented a watch 1.

This watch 1 comprises a middle part 2, which may in particular be made of metal (for example steel), or of a synthetic material (for example in a composite material comprising a polymer matrix loaded with fibers, typically carbon).

The watch 1 also includes, for wearing on the wrist, a bracelet 3 which is fixed on the middle part 2 between horns 4 formed projecting therefrom.

The watch 1 further comprises an ice and a bottom (not shown), fixed on the middle part 2 on either side thereof.

The watch 1 comprises, finally, a clockwork movement, hereinafter simply called "movement", which comprises a plate 6 intended to be housed in the middle part 2 being fixed thereto, e.g. by means of screws. The plate 6 forms a support for various mechanisms such as cog, regulating organ, exhaust, transmission, timer, winding (non-exhaustive list).

This clockwork movement is mechanical, its power source being provided by a mainspring and regulated by a spring oscillator. To house this oscillator, the movement 5 integrates a regulating organ 7, which is mounted on the plate 6.

The regulating member 7 comprises, in the first place, a bridge 8. This bridge 8, also called "cock", is in the form of a rigid piece (which may be metallic) fixed on the plate 6. The bridge 8 forms both support and guide for the other components of the regulating organ 7.

According to an embodiment illustrated in the drawings, and in particular on the FIG.1 and on the FIG.3 , the bridge 8 comprises a base 9. It is through this base 9 that the bridge 8 is fixed on the plate 6 by means of a screw 10 which, passing through a hole 11 formed in the base 9, comes into helical engagement with a tapped hole 12 drilled in the plate 6.

The precise positioning of the bridge 8 with respect to the plate 6 is ensured by means of feet 13 which project from an internal face of the base 9 and fit into complementary bores 14 made in the plate 6.

For fixing and guiding the other components of the regulating member 7, the bridge 8 comprises an apron 15, formed integrally with the base 9. The bridge 8 is provided with a bore 16 formed in the apron 15, at an end cantilevered thereof.

The regulating member 7 comprises, secondly, a main axis 17, which is in the form of a stepped piece integral rotatably mounted relative to the bridge 8. More specifically, the main axis 17 is rotatably mounted between the platinum 6 and bridge 8.

According to a particular embodiment (illustrated in particular on FIG.4 and FIG.5 ), to ensure the rotation of the shaft 17 relative to the bridge 8, the regulating member 7 comprises a shock absorber 18, driven into the bore 16, and which comprises, on an inner face, a hole 19 for guiding a first end of the main axis 17.

As we see elsewhere on the FIG.1 , the plate 6 is provided with a hole 20 for guiding a second end of the main axis 17.

To limit the friction during the rotation of the main axis 17, the ends thereof advantageously cooperate with a hard mineral, such as ruby or diamond.

The regulating member 7 comprises, thirdly, a spring 21 wound spirally around the main axis 17. More specifically, the spring 21, hereinafter called "spiral" has an inner end 22, integral with the axis 17, and an outer coil 23 which terminates in an outer end 24.

According to an advantageous embodiment, the hairspring 21 is made of silicon, optionally covered with an oxide layer.

When armed, the hairspring 21 provides a return torque exerted on the axis 17.

To increase this torque provided by the hairspring 21 and the amplitude of its oscillations, the regulating member 7 comprises, fourthly, an inertia flywheel in the form of a rocker 25 integral in rotation with the axis 17.

This pendulum 25, made e.g. brass, comprises a hub 26, by which it is driven on the axis 17, a serge 27, and radii 28 (here three in number, but this number is only illustrative) which connect the hub 26 to the serge 27.

The regulating member 7 comprises, in the fifth place, a stud holder 29 which comprises a ring 30, by which it is secured to the bridge 8, and a pair of legs, namely a front tab 31 and a rear tab 32 (front). and rear being defined in the winding direction of the hairspring 21, from the inner end 22 towards the outer end 24) which project radially from the ring 30 and, together, define a notch 33.

The stud carrier 29 is advantageously made of a metallic material, e.g. in steel.

According to an embodiment illustrated on the FIG.4 , the ring 30 of the holder 29 is driven on a shaft 34 which projects from the deck 15 coaxially with the bore 16.

The regulating member 7 comprises, sixthly, a peg 35 secured to the outer end 24 of the hairspring 21. This peg 35 is e.g. made of steel. According to one embodiment, the stud 35 is fixed to the outer end 24 of the hairspring 21 by gluing, by means of a photo-polymerizable glue whose adhesion properties are activated by exposure to photonic radiation in the ultraviolet .

• une tête 37 élargie par laquelle le piton 35 est en appui contre le porte-piton 29,
• une fourche 38 dans laquelle est logée (en étant collée) l'extrémité 24 externe du spiral 21.

As illustrated in the drawings, and more particularly on the FIG.4 , FIG.5 , FIG.7 and FIG.8 , the stud 35 comprises a cylindrical body 36 through which the pin 35 is snapped into the notch 33, and on either side of the body 36:

• an enlarged head 37 by which the bolt 35 bears against the bolt carrier 29,
• a fork 38 in which is housed (while being glued) the outer end 24 of the hairspring 21.

Thus fixed on the bolt carrier 29, the bolt 35 ensures the securing (that is to say the immobilization with respect to the bridge 8) of the outer end 24 of the hairspring 21.

The oscillations of the hairspring 21 are maintained (and counted) by an escapement anchor (not shown) which communicates a kinetic energy, which arms the hairspring 21 by dragging it beyond its equilibrium position.

By disarming, that is to say, tending to regain its equilibrium position, the hairspring 21 rotates the axis 17 main, which it is secured by its inner end 22, with the balance 25 which is itself secured to the axis 17. Having reached a complete relaxation, the spring 21 stops (with the axis 17 and the balance 25 ) then, under the effect of its elasticity, tends to compress again and then causes the axis 17 and the balance 25 in a rotation in the opposite direction.

The oscillations of the spiral 21-pendulum 17 system serve to regulate the alternating tilting movements of the escapement anchor, which is provided with a pair of vanes alternately striking an escape wheel whose rotation is step-by-step, at a frequency determined by the oscillations of the anchor (that is to say of the spring), is transmitted to a timer provided with one (or more) indicator needle (s) hours (and / or minutes) .

The frequency of the oscillations of the spiral 21 - pendulum 17 system can be finely adjusted, by hand, by an intervention on the regulating organ 7, which comprises for this purpose, in seventh place, a racket 39.

The racket 39 is fixed on the bridge 8 with the possibility of angular displacement relative thereto around the main axis 17.

• une queue 40 portant une clé 41 qui définit une paire de butées 42 disposées de part et d'autre de la spire 23 externe du spiral 21, et
• au moins un doigt 43 d'indexage qui coopère avec un excentrique 44, monté sur le pont 8 pour ajuster la position angulaire de la raquette 39 par rotation de l'excentrique 44.

More specifically, the racket 39 comprises:

• a tail 40 carrying a key 41 which defines a pair of stops 42 disposed on either side of the outer coil 23 of the spiral 21, and
• at least one indexing finger 43 which cooperates with an eccentric 44, mounted on the bridge 8 to adjust the angular position of the racket 39 by rotation of the eccentric 44.

• Un élément 45 supérieur de raquette, qui porte le doigt 43 d'indexage ;
• Un élément 46 inférieur de raquette, qui porte la queue 40.

According to a preferred embodiment illustrated in particular on FIG.4 and FIG.5 racket 39 comprises two distinct integral elements, namely:

• An upper racket member 45 which carries the indexing finger 43;
• A lower racquet element 46, which carries the tail 40.

In the illustrated example, the upper element 45 comprises a central ring 47 and a pair of indexing fingers 43 which extend radially in V from this central ring 47.

In this same example, the lower element 46 comprises a ring 48; the tail 40 comprises a pair of tongues 49 which protrude radially from the ring 48 and define therebetween a slot 50 in which the key 41 is inserted.

The central ring 47 of the upper element 45 comprises a bushing 51 protruding into the ring 48 of the lower element, which secures the upper element 45 and the lower element 46.

Furthermore, the central ring 47 of the upper element 45 is provided with a chamfer 52 complementary to a conical bearing surface 53 formed on the shock absorber 18, which ensures the rotational guidance of the racket 39 around the axis 17.

The stops 42 form, together for the hairspring 21, a counting point, which with the internal end 22 defines an active (curvilinear) length on which depends the frequency of the oscillations of the hairspring 21. The (manual) rotation of the eccentric 44 varies the angular position of the racket 39 and therefore the counting point, which increases (or, conversely, decreases) the active length (and thus the frequency of the oscillations) of the hairspring 21.

According to an embodiment illustrated on the FIG.2 and FIG.4 the finger (s) is (are) housed in a hollow reserve 54 formed in the apron 15 of the bridge 8. A graduation 55, as well as "-" and "+" signs, engraved in the apron 15, provide the watchmaker with indications on the scale and the direction of rotation, useful to enable him to adjust finely (by magnifying glass or microscope, or by means of a specific apparatus, such as the REGO model marketed by the company CENTAGORA) the position of the eccentric 44 (notched for this purpose) - and therefore the racket 39.

During manual interventions on the regulating member 7, the mastication, that is to say the withdrawal of the stud 35 of the stud holder 29, may be necessary. In order to prevent the peg 35 released from the bolt carrier 29 from being thrown off by a sudden detent of the hairspring 21, the bolt carrier 29 is provided with a retaining stop for the bolt 35 extracted from the bolt. notch 33.

More specifically, the rear lug 32 of the bolt carrier 29 comprises an extension 56 which defines, beyond the notch 33, a bend 57 forming this abutment.

• Une section 58 intérieure, qui avec la patte 31 avant définit l'encoche 33,
• La prolongation 56, qui s'étend radialement dans la continuité de la section 58 intérieure.

Thus, the rear tab 32 comprises, in one piece:

• An inner section 58, which with the front tab 31 defines the notch 33,
• The extension 56, which extends radially in the continuity of the inner section 58.

According to an embodiment illustrated in the drawings, and more particularly on the FIG.6 and FIG.9 , the extension 56 comprises a portion 59 radial (substantially collinear with the 58), and a transverse portion 60 which extends the radial portion 59 at right angles.

The bend 57 is defined at the junction between the radial portion 59 and the transverse portion 60.

As can be seen from the FIG.9 , the transverse portion 60 of the extension 56 is advantageously spaced from the tab 31 before forming with it a passage 61 wide enough to allow the introduction (or forced removal) of the stud 35, transversely.

The rear tab 32 preferably has an internal connection fillet 62 at the bend 57.

The stud 35 snapped into the notch 33 is illustrated in dashed lines on the FIG.7 and on the FIG.10 . In this position, the body 36 of the stud 35 cooperates with the facets of the notch 33 which thus ensures its retention for the purposes of the ordinary operation of the spiral 21 (and therefore the movement 5).

The pin 35 is extracted (that is to say unclipped) from the notch 33 manually, by a radial outward movement (that is to say tending to move the stud 35 from the ring 30) , in the direction indicated by the arrows on the FIG.7 and FIG.10 . Or the equilibrium position of the hairspring 21 is reached when the pin 35 is in the notch 33 of the peg carrier. During manual intervention, the pin therefore tends to return, and thus to stall in the elbow 57 (and more precisely in the leave 62) where it is thus held, as shown in solid lines on the FIG.8 and FIG.10 .

The elbow 57 (and therefore the stop that it forms) can unclip the stud 35 without risk of it escaping when it is extracted from the notch 31.

It is then possible to change the catch of the pin 7 to ensure a firmer hold and then completely free the bolt carrier 29, e.g. to disassemble the hairspring 21.

As the pin 35 is then retained by the abutment formed by the elbow 57, it is possible to subsequently change the tool to ensure a more comfortable (and firm) grip of the pin 35 (eg by means of a pair of pins). tweezers) in view for example to completely disassemble the hairspring 21, by a vertical movement, as illustrated by the arrow on the FIG.10 . In other words, the polishing is done in two stages.

This results in a decreased or even eliminated risk of breakage of the hairspring 21 during the buckling, in favor of the reliability of the regulating member 7.

Claims (10)

A stud post (29) for a mechanical watch movement (5), which comprises a pair of legs, namely a front tab (31) and a rear tab (32), together defining a notch (33), the tabs (32, 33) being arranged so that a pin (35) can be held in the notch (33),
characterized in that the rear lug (32) of the bolt carrier (29) comprises an extension (56) which defines, beyond the notch (33), an elbow (57) forming a retaining stop for the bolt (35) when said peg (35) is extracted from the notch (33). A stud carrier (29) according to claim 1, characterized in that the extension (56) comprises a radial portion (59) and a transverse portion (60) which extends at the right angle the radial portion (59), the elbow ( 57) being defined at the junction between the radial portion (59) and the transverse portion (60). A stud carrier (29) according to claim 2, characterized in that the portion (60) transverse of the extension (56) is spaced from the tab (31) before forming with it a passage (61) transverse to the piton ( 35). Spacer (29) according to one of claims 2 or 3, characterized in that the lug (32) rear has a fillet (62) for internal connection at the elbow (57). Assembly (7) for a mechanical clockwork movement (5), comprising a stud holder (29) according to one of the preceding claims and a stud (35), characterized in that the stud (35) has a body ( 36) by which it is snapped into the notch (33), and on either side of the body (36): - An enlarged head (37) by which the pin (35) is in abutment against the door pin (29), a fork (38) in which an outer end (24) of a spring (21) of the movement (5) is intended to be housed. Assembly (7) according to the preceding claim, further comprising a racket (39) which comprises two separate integral elements, namely: - An upper racket member (45), which forms a pair of indexing fingers (43) for adjusting the angular position of the racket (39); - A lower racquet element (46), which forms a tail (40). Assembly (7) according to claim 6, characterized in that the upper element (7) comprises a ring (47) central, the pair of indexing fingers (43) extending in V from this ring (47). ) central. Assembly (7) according to one of claims 6 or 7, characterized in that the tail (40) comprises a pair of tabs (49) which define between them a slot (50) allowing the insertion of a key (41). ). Movement (5) mechanical clockwork, which incorporates an assembly (7) according to one of claims 5 to 9. Watch (1) comprising a mechanical clockwork movement (5) according to claim 9.

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