EP3644133A1 - Chiming watch - Google Patents

Abstract

Watch (1) with striking ring comprising: • a case comprising a middle part (3) enclosed, on the one hand, by a base (7) and, on the other hand, by a crystal (5), said case housing a watch movement (13), a striking mechanism (21) and a waterproof sound transmission membrane (8) located between said movement (13) and said bottom (7); • at least one stamp (19) carried by a heel ( 17), said at least one stamp (19) being arranged to be struck by at least one hammer (21a) which comprises said striking mechanism (21); characterized in that said heel (17) is associated with a movable part ( 23a) that comprises a support 23, said movable part (23a) having substantially only one degree of freedom in rotation, and in that a sound transmission bridge (25) is integral with said movable part (23a), said bridge transmission (25) extending in a gap formed between said movement (13) and said membrane (8) and comprising a free end (25b) in contact with said membrane (8) in a predefined contact zone.

Description

Technical area

The present invention relates to the field of watchmaking. It relates, more particularly, to a watch comprising a ringing device with improved acoustics.

State of the art

In ringing watches, the recurring problem that arises is the perceptible loudness outside the case. Since it is essential to protect the movement and the striking device from humidity and dirt, the case is typically sealed by means of a solid bottom or a waterproofing membrane, the stamps being arranged inside the waterproof envelope thus created.

Consequently, the sounds produced when the gongs are struck by hammers are attenuated when they pass through the case and / or the membrane.

Various solutions have been proposed in order to minimize this attenuation. The document EP2942675 , for example, reveals a striking timepiece in which the base of the stamp transmits vibrations directly around a membrane located between a perforated bottom and the movement. In doing so, the amplitude of the vibrations of the membrane is increased. In another example, the document CH710200 reveals a watch with a stamp on the bezel, which makes the glass vibrate when the latter rings and thus transmits sound vibrations to the outside environment.

The document CH698742 reveals another striking timepiece in which a mechanical link is established between the stamp holder and the glass via a pillar, in order to vibrate the latter.

Finally, the document FR2777095 describes a musical watch in which a keyboard is fixed on an annular resonance cavity, itself in contact with a dial in order to increase the amplitude of vibration of the latter.

However, these solutions are not entirely satisfactory since the sound transmission to the outside of the case is still unsatisfactory, the ringtones being thus too weak. Furthermore, the size of the acoustic arrangements disclosed in these documents is relatively high. A solution aimed at maximizing the intensity of the noise produced is revealed by the document FR1042749 , which reveals an alarm clock in which a hammer hits a stud which is integral with the membrane. The sound produced is certainly loud, but is extremely unpleasant in comparison with the melodious tone of a timbre.

The object of the invention is therefore to propose a striking timepiece in which the above-mentioned faults are at least partially overcome.

Disclosure of invention

More specifically, the invention relates to a striking watch, in particular a wristwatch, pocket watch or other watch intended to be worn daily by a user. This watch comprises a case comprising a middle part enclosed, on the one hand, by a back and, on the other hand, by a crystal in a conventional manner. This case houses a watch movement of any kind, a striking mechanism, integrated or not to said movement, as well as a waterproof sound transmission membrane located between said movement and said back. In order to provide sounds, the system comprises at least one stamp carried by a heel, said at least one stamp being arranged to be struck by at least one hammer that comprises said striking mechanism. It is also possible to provide several heels, each carrying one or more stamps.

According to the invention, said heel is associated with a movable part that includes a support, said heel being for example made of one piece with, fixed to or in contact with said movable part. The latter is arranged to present substantially only one degree of freedom in rotation, for example about an axis of rotation.

The watch further comprises a sound transmission bridge integral with said support and extending in the space formed between said movement and said membrane, said sound transmission bridge comprising a free end in direct or indirect contact with said membrane in a predefined contact area.

This sound transmission bridge transmits vibrations from the heel, generated by those of the gong, when struck by the hammer, directly to said membrane in an optimal direction of vibration to vibrate the latter, which increases the volume of the perceptible sound. on the outside of the watch. The bridge can even constitute a mechanical amplifier in the case where the lever arm, considered between the axis of rotation and the zone of contact with the membrane, is greater than that considered between the axis of rotation and the junction between the gong and the heel, which increases the amplitude of the vibrations of the membrane, and thus the sound volume even more significantly.

Advantageously, said heel is integral with said movable part of said support, by being fixed to, or coming integrally with the latter. In doing so, the vast majority of the vibrations generated by the patch and transmitted to the heel are also transmitted to said movable part of said support, and thus to the bridge and to the membrane. The volume of the sound is thus increased.

Advantageously, said support is attached to a fixed element of said watch, such as for example a frame element (plate, bridge) or an element of the watch case (middle or other) by means of a pair of bars. torsion extending on either side of said movable part, said torsion bars being arranged to define said axis of rotation. These torsion bars can for example be coaxial with respect to each other and can extend parallel to the plane of said movement. This arrangement is very compact, especially in the height of the watch. Other suspension arrangements of the mobile part are also possible.

Advantageously, the contact zone between said free end of said sound transmission bridge and said membrane is located substantially in the center of the latter, which optimizes the transmission of vibrations between said transmission bridge and said membrane. However, this contact zone can be located anywhere on the membrane, preferably within a radius equal to half that of the membrane.

Advantageously, said free end of said sound transmission bridge comprises a stud adjustable in height, that is to say in a direction perpendicular to the membrane at the contact area between the stud and the membrane, which allows the watchmaker optimize the contact force between these two elements and thus optimize the volume and / or sound quality.

Advantageously, the ratio between, on the one hand, the lever arm acting between said axis of rotation and said contact zone and, on the other hand, the lever arm acting between said axis of rotation and the heel, is at least two, preferably at least three, in order to maximize the volume of sound perceptible to the user.

Advantageously, said stamp extends along a groove formed in a frame element linked to said movement, which represents a very compact construction.

Advantageously, a support board is arranged between said membrane and said movement so as to form a stop for said membrane in the event of external overpressure. Damage to the membrane due to such overpressure (for example during a dive) is thus avoided.

Advantageously, said support board has an elongated opening in which takes place at least part of said transmission bridge, which represents a compact construction in height, since it is not necessary to arrange the support board in superposition of the transmission bridge.

Brief description of the drawings

• Fig. 1 est une vue isométrique coupée d'une montre selon l'invention ;
• Fig. 2 est une vue isométrique du timbre, talon, support etc. de ladite montre ;
• Fig. 3 est une vue isométrique de ladite montre, les éléments d'habillage ayant été supprimés ; et
• Fig. 4 est une vue similaire à celle de la fig. 3, la bague porte-fond ainsi que la planche de support étant représentées.

Other details of the invention will appear more clearly on reading the description which follows, given with reference to the appended drawings in which:

• Fig. 1 is an isometric view cut from a watch according to the invention;
• Fig. 2 is an isometric view of the stamp, heel, support etc. of said watch;
• Fig. 3 is an isometric view of said watch, the covering elements having been removed; and
• Fig. 4 is a view similar to that of the fig. 3 , the bottom support ring and the support board being shown.

Modes of Carrying Out the Invention

The figures 1 to 4 illustrate a watch 1 according to the invention. Conventionally, this watch 1 comprises a case formed by a peripheral middle part 3 closed on the "front" side by a crystal 5 and closed on the "rear" side by a bottom 7, intended to be in contact with the arm or the wrist of the wearer when watch 1 is worn. For this purpose, the middle part 3 also carries horns 9 arranged for the attachment of a bracelet strand. Alternatively, watch 1 can be a pocket watch, a pendant watch or the like, and can thus include a bail or other means for attaching a chain or the like instead of horns 9.

The bottom 7 has openings 7a which allow the passage of sound waves, and the casing is sealed by means of a membrane 8 sandwiched between the bottom 7 and a bottom-holding ring 10 which is itself integral with the middle part 3. Various seals 14 are provided in a conventional manner in order to make the membrane 8 waterproof with respect to the base-holder ring 10 and also to make the latter waterproof with respect to the middle part. Other constructions are also possible. For example, the membrane 8 can be welded or glued to the bottom-holder ring 10 or the bottom 7 can be fixed directly to the middle part 3, the membrane 8 being held sandwiched between these two elements. We note that the membrane 8 can be made of metal (in particular titanium or amorphous metal), polymer, or any other material known to those skilled in the art for this application.

The case houses a movement 13, which can be of the mechanical, electrical, electronic or hybrid type. In the illustrated embodiment, the movement 13 is mechanical and self-winding, an automatic winding device being arranged on the bottom side of the movement 13 and arranged to wind a barrel that comprises the movement 11.

The movement 13 is linked to a frame 12 which is fixed in the middle part in a conventional manner and which supports a striking mechanism 21. The frame 12 at least partially defines a peripheral cavity 15 in which a heel 17 is located at least partially as well as 'a stamp 19 secured to said heel 17. This cavity 15 serves as a sounding box and, in a construction variant not shown, at least part of the cavity 15 may be constituted by an annular gap formed between, of on the one hand, the external wall of the frame 12 and, on the other hand, the internal wall of the middle part 3. In such a case, the heel 17 and the stamp 19 can be contained at least partially in this gap.

The stamp 19 is arranged to be struck by a hammer 21a (see the figure 2 ) forming part of said striking mechanism 21. The latter is represented here as an additional module, distinct from movement 13, but can alternatively be integrated into said movement 13. Of course, striking mechanism 21 can be of any type (alarm clock, repetition, ringing by the way, big ringing), and may also include several stamps 19, extending on either side of said heel 17, or in superposition relative to one another, in order to ring two different tones. Arrangements of three, four or even more stamps fixed to the same heel 17 are also possible, and it is also possible to provide several heels 17 on the same movable part 23a.

In order to support the heel 17, the latter is associated with a support 23 and is fixed to a movable part 23a which the latter comprises. In the mode of illustrated embodiment, the heel 17 is fixed to said movable part 23a by means of screws (then not visible), by welding or by gluing. It is also possible that the heel 17 can be integrated into the movable part 23a by coming integrally with this movable part 23a. In doing so, the heel 17 and the stamp 19 are completely free from contact with any element other than said movable part 23a, and are thus suspended by the support 23; the vast majority of the vibrations of the heel 17, generated by the gong 19, being thus transmitted to the mobile part 23a of the support 23.

However, in a variant not illustrated, it is also possible that the heel 17 can be fixed to another fixed element such as a frame element 12, the middle part 3 or the like, said movable part 23a being in contact with said heel 17 However, even if such an alternative arrangement represents an improvement over the prior art, the results are mixed compared to the illustrated variant since a significant part of the vibrations of the heel 17 will be lost due to the interaction between the heel 17 and the fixed element of which it is integral.

The mobile part 23a of the support 23 is suspended on the frame by means of two torsion bars 23b each extending between said mobile part 23a and a corresponding fixing element 23c. These two fastening elements 23c located on either side of said movable part 23a, and are arranged to be fixed to a frame element 12 or of the case (for example the middle part 3).

In the illustrated embodiment, the fastening elements 23c are screwed onto the frame 12 (see the figure 3 ), the torsion bars 23b are straight and extend along an axis of rotation 23d, which represents the only substantial degree of freedom of the movable part 23a. However, other suspension configurations of the mobile part 23a are possible, the important aspect being the only degree of freedom in rotation about an axis 23d which is parallel to the membrane. For example, the torsion bars 23b can be curved, inclined relative to the plane of the membrane 8 or the like. By "only substantial degree of freedom" is meant that this degree of freedom has a stiffness at least five times, preferably at least ten times, smaller than the stiffness along the other orthogonal axes of rotation.

Alternatively, the torsion bars 23b can be replaced by a flexible ball joint, an RCC (remote center compliance) pivot or other flexible ad hoc guide fixed to the middle part 3 or to a frame element, or even a pin hinge provided a return spring. In terms of flexible pivots, the applicant refers to the work Design of flexible guides, Simon Henein, PPUR 2003 , which reveals several guides suitable for the present case.

A sound transmission bridge 25 is fixed at its proximal end 25a to said movable part 23a, by being screwed, glued, welded or the like. Said bridge 25 is of elongated shape and extends in the gap formed between the movement 13 and the membrane 8, being in permanent contact with the latter in a predetermined contact zone near its distal end 25b, which is its end. free. This contact can, of course, be direct or indirect via any intermediary element.

For this purpose, said distal end 25b can carry an adjustable stud 25c (see the figure 2 ), which can be adjusted (for example by screwing it to approach or move away from the movement 13) to press against the membrane 8 with a predetermined force. However, this stud 25c is not compulsory and the figures 3 and 4 illustrate bridges 25 devoid of studs, and the distal ends 25b of which simply have planar circular surfaces defining contact with the membrane 8. Of course, other shapes of surfaces are also possible, whether they be planar, curved surfaces, annulars or bumps projecting from bridge 25 or the like.

Advantageously, said contact zone is located substantially in the middle of the membrane 8, or at least within a radius of 50%, 75% or even 90% less than that of the membrane 8, but nothing prevents that the contact can be closer to the periphery of the latter.

It should also be noted that the membrane 8 can be made integral with the distal end 25b of the bridge 25 by means of a screw, welding, a shore, a rivet, by glue or by any other appropriate means.

Since the movable part 23a of the support is supported so as to pivot about a single axis of rotation 23d substantially parallel to the plane of the membrane 8, and that the bridge 25 is longer than the distance between the axis 23d and the point attaching the stamp 19 to the heel 17, the bridge serves as a transformer for the direction of action of the vibrations of the stamp 19. These vibrations take place mainly (but not exclusively) in the plane of the stamp 19, in particular since it is struck by the hammer 21a in a direction which is in this same plane. However, the optimal direction of excitation of the membrane 8 is perpendicular to the plane of the latter, that is to say orthogonal to the main vibrations of the timbre 19. The substantially L-shaped shape of the bridge 25 - part mobile 23a thus modifies the direction of action of the vibrations by 90 °, in order to make the membrane 8 vibrate better.

Furthermore, the elongated shape of said transmission bridge 25 can act as a mechanical amplifier, the amplitude of the vibrations of the heel 17 being magnified due to the ratio between, on the one hand, the lever arm of the contact zone between the bridge 25 and the membrane 8 and, on the other hand, the lever arm of the stamp, according to the elementary law of the levers. These lever arms are shown schematically on the figure 2 . The lever arm B1 extends between the axis of rotation 23d and an axis passing through the midpoint of the section of the patch 19 at the place where the latter meets the heel 17, this axis 27a being substantially parallel to the axis of rotation 23d. The lever arm B2 intersects said axis of rotation 23d as well as an axis 27b which is orthogonal to the membrane 8 at the center of the contact zone between the stud 25c and the membrane 8, the lever arm B2 also being orthogonal to the 'axis 27b. The B2 / B1 ratio between these two lever arms is at least 2, preferably at least 3. In the illustrated embodiment, this ratio is 3.2.

Comparative hearing tests have shown that the arrangement of the invention increases the perceptible sound volume significantly compared to a conventional striking watch.

In order to protect the membrane 8 from overpressure, for example during a dive, the bottom support ring 10 has come integrally with a support board 29, provided with openings 29a which pass through its thickness to allow the transmission of sound waves from inside the box to the membrane 8. During a dive, for example, the membrane 8 is pushed by the pressure of ambient water against said board 29, which limits its travel and thus the constraints it undergoes.

Although it is possible to arrange the board 29 so that only the distal end 25c of the transmission bridge 25 crosses it, it is advantageous to provide an opening 29b in the form of an elongated slot arranged to at least partially house said said transmission bridge 25 in the thickness of said board 29. In doing so, the height of the system can be minimized.

It goes without saying that the support board 29 can alternatively be formed of a separate piece, fixed to said bottom-holder ring 10, or, in the absence of the latter (for example in the case of the middle part 3 bears directly the bottom 7), may be an element fixed to the middle part 3 or to the bottom 7, or held sandwiched between the latter. That said, the presence of said board 29 is not compulsory.

Although the invention has been described above in connection with specific embodiments, additional variants are also possible without departing from the scope of the invention as defined by the claims.

Claims (10)

Watch (1) with striking mechanism comprising: • a case comprising a middle part (3) enclosed, on the one hand, by a bottom (7) and, on the other hand, by a crystal (5), said case housing a watch movement (13), a striking mechanism (21) as well as a waterproof sound transmission membrane (8) situated between said movement (13) and said bottom (7); • at least one stamp (19) carried by a heel (17), said at least one stamp (19) being arranged to be struck by at least one hammer (21a) that comprises said striking mechanism (21); characterized in that said heel (17) is associated with a mobile part (23a) which comprises a support 23, said mobile part (23a) having substantially only one degree of freedom in rotation,
and in that a sound transmission bridge (25) is integral with said movable part (23a), said transmission bridge (25) extending in a gap formed between said movement (13) and said membrane (8) and comprising a free end (25b) in contact with said membrane (8) in a predefined contact zone. Watch (1) according to the preceding claim, wherein said heel (17) is integral with said movable part (23a) of said support (23). Watch (1) according to one of the preceding claims, wherein said support (23) is attached to a fixed element (12) of said watch (1) via a pair of torsion bars (23b) s extending on either side of said movable part (23a), said torsion bars (23b) being arranged to define said axis of rotation (23d). Watch (1) according to the preceding claim, wherein said torsion bars (23b) are coaxial with each other, and extend parallel to the plane of said movement (13). Watch (1) according to one of the preceding claims, wherein said contact zone between said free end (25b) of said sound transmission bridge and said membrane (8) is located substantially in the center of the latter. Watch (1) according to one of the preceding claims, in which said free end (25b) of said sound transmission bridge comprises an adjustable stud (25c) in height in contact with said membrane (8). Watch (1) according to one of the preceding claims, in which the ratio between on the one hand the lever arm (B2) acting between said axis of rotation (23d) and the midpoint of said contact zone and of on the other hand the lever arm (B1) acting between said axis of rotation (23d) and the midpoint of the junction between said at least one stamp (19) and the heel (17), is at least two, preferably at least three. Watch (1) according to one of the preceding claims, wherein said at least one stamp (19) extends along a groove (15) formed in a frame element (12) linked to said movement (13). Watch (1) according to one of the preceding claims, further comprising a support board (29) located between said membrane (8) and said movement (13) so as to form a stop for said membrane (8) in external overpressure. Watch (1) according to the preceding claim, wherein said support board (29) has an elongated opening (29b) in which takes place at least a portion of said transmission bridge (25).

Images