Sound-separation unit for a clock striking mechanism

Description

Technical field

[0001] The present invention relates to a heel-gong assembly for a striking mechanism of a timepiece comprising a heel, a first gong comprising a first end secured to the heel and a second gong comprising a second end secured to the heel, said first and second gongs extending respectively from one side of the heel in opposite directions.

[0002] The present invention also relates to a striking mechanism comprising such a heel-gong assembly as well as a timepiece comprising such a striking mechanism.

[0003] The present invention also relates to a method of manufacturing such a heel-stamp assembly using a shaping fixture as well as said shaping fixture. State of the art

[0004] A striking timepiece equipped with such a striking mechanism is, for example, a striking watch (such as a minute repeater, grande sonnerie, petite sonnerie, alarm clock) comprising, for example, two hammers and two gongs, generators of vibrations, arranged to be struck by their respective hammer when the striking mechanism is engaged to generate vibrations in order to produce a sound.

[0005] Gongs are traditionally made of wires wound around the movement. The gongs are mounted securely on a heel or gong holder, which is attached to a part of the watch to transmit the gongs' vibrations to the wearer. Traditionally, gongs are configured to produce different sounds, one for striking the hours and the other for striking the minutes.

[0006] Application EP 2 942 674 describes, for example, a heel-gong assembly comprising a heel or gong holder and two wound gongs. The example shown shows two gongs conventionally wound in the form of overlapping, parallel circles, positioned on the heel at different heights. The gongs can also describe a corkscrew shape around the watch movement. The gongs are wound in opposite directions and are not in contact with each other. However, the technical problem of application EP 2 942 674 is to be able to easily produce a heel-gong assembly and change the gong, the proposed solution being to produce the gong and its gong holder at the same time as a mounting element in a watch case to form a single part.

[0007] Until recently, minute repeaters were not amplified. The main point was to have a gong heel rigidly attached to the movement or caseband. The gongs are fixed in the heel by extending in opposite directions, and by being positioned relative to each other with a sufficient difference in height so that they can wrap flat and parallel around the movement without touching when they are placed on top of each other.

[0008] Recent developments, particularly in minute repeater watches, have proposed various systems for significantly amplifying the sound of chimes.

[0009] However, while these new systems allow for the amplification of the ringing, they also highlight a difference in sound level between the ringing of the two gongs (the hour and the minute) due to the difference in height of the gongs in relation to the transmission zone of their vibrations.

[0010] To solve this problem, patent CH 706 720 proposes, more particularly for cathedral gongs secured to a heel fixed on the plate of a movement, to use a heel-gong assembly in which the two gongs extend from the heel in the same plane to an area where, to avoid meeting, they change trajectory, one of the gongs changing radius and the other gong changing plane. It is therefore proposed to use a flat spiral-shaped gong and a helical-shaped gong extending from the heel in the same plane.

[0011] However, in this configuration, the two stamps are not parallel at all points, which leads to a risk of contact between the stamps. This requires, on the one hand, increasing the radius of the flat stamp and, on the other hand, providing, for the helical stamp, a sufficiently large pitch, in order to guarantee sufficient spacing between the stamps with the required safety features, hence an increase in the overall dimensions in diameter and in Z of the proposed heel-stamp assembly.

[0012] This solution is therefore not satisfactory when the watchmaker has limited space, particularly in diameter, for placing the gongs around the movement.

[0013] It is therefore necessary to have a set of at least two timbres from which a similar amplification can be obtained in a limited diameter footprint. Disclosure of the invention

[0014] To this end, the invention relates to a heel-gong assembly for a striking mechanism of a timepiece comprising a heel, a first gong comprising a first end secured to the heel and a second gong comprising a second end secured to the heel, said first and second gongs extending respectively from one side of the heel in opposite directions, the first gong being wound in a first helix and the second gong being wound in a second helix, said first and second helices being wound in opposite directions from the heel, the winding directions and the pitches of the first and second helices being chosen so as to have no contact between said first and second gongs.

[0015] According to the invention, the first end of the first stamp and the second end of the second stamp are arranged in the same plane relative to the heel so as to be positioned on the heel at the same height.

[0016] The helical configuration of each of the timbres advantageously allows for a Z-shaped size, in thickness, that is to say the height of the movement and the amplification of the timbres is identical for the two notes.

[0017] In a particularly advantageous embodiment, at least one of the first helix and the second helix, and preferably each of the first and second helixes, is a circular helix.

[0018] This configuration advantageously allows the diameter to be kept to a minimum, and the gongs to be placed around the movement even in a restricted space.

[0019] Preferably, the first helix and the second helix have different radii, in order to give the timbres different notes.

[0020] In a particularly preferred embodiment, the first helix and the second helix have the same pitch in absolute value, in order to obtain timbres whose turns are in parallel planes.

[0021] Preferably, the first and second timbres each extend over less than one revolution.

[0022] The present invention also relates to a striking mechanism of a timepiece comprising a heel-gong assembly as defined above, and first and second hammers intended to strike the first and second gongs respectively.

[0023] According to a preferred embodiment, the striking mechanism also comprises a lever linked to a support by an articulation along a single axis of rotation and secured to a membrane, said lever being secured to the heel of the heel-gong assembly.

[0024] The present invention also relates to a timepiece comprising a striking mechanism as defined above.

[0025] The present invention also relates to a method of manufacturing a heel-stamp assembly as defined above, comprising the following steps: fixing the first end of the first stamp and the second end of the second stamp respectively on a first and second side of the heel, the first end of the first stamp and the second end of the second stamp being arranged in the same plane relative to the heel so as to be positioned on the heel at the same height;arranging the heel-stamp assembly in a shaping fixture which comprises a lower element having an imprint corresponding to the helical shape of one of the stamps and to the shape of the lower part of the heel, an upper element having an imprint corresponding to the helical shape of the other of the stamps and to the shape of the upper part of the heel, the lower and upper elements being arranged to fit together, their respective imprints facing each other, and a separating plate arranged between the lower element and the upper element and inserted between the two stamps, said separating plate having a helical shape arranged so that its lower face is in contact with the stamp housed in the lower element and so that its upper face is in contact with the stamp housed in the upper element; ; carry out at least one heat treatment of the heel-stamp assembly inserted in its shaping position; remove the heel-stamp assembly from its shaping position.

[0026] The present invention also relates to a shaping fixture for manufacturing the heel-stamp assembly by the method as defined above, said fixture comprising a lower element having an imprint corresponding to the helical shape of one of the stamps and to the shape of the lower part of the heel, an upper element having an imprint corresponding to the helical shape of the other of the stamps and to the shape of the upper part of the heel, the lower and upper elements being arranged to fit together, their respective imprints being opposite each other, and a separating plate arranged to be disposed between the lower element and the upper element and being intended to be inserted between the two stamps,said separation plate having a helical shape arranged so that its lower face is in contact with the stamp intended to be housed in the lower element and so that its upper face is in contact with the stamp intended to be housed in the upper element.,

[0027] The method and the installation according to the invention make it possible, for example, to produce a heel-gong assembly in which all the turns of the gongs are in perfectly parallel planes. Brief description of the drawings

[0028] Other characteristics and advantages of the present invention will appear on reading the following detailed description of an embodiment of the invention, given by way of non-limiting example, and made with reference to the appended drawings in which: there Figure 1 is an isometric view from above of a striking mechanism according to the invention; Figure 2is a side isometric view of the mechanism of the Figure 1 ; there Figure 3 is a top view of a heel-stamp assembly according to the invention; Figure 4 is an isometric view of the heel-stamp assembly of the Figure 3 seen from the rear; the Figure 5 is a sectional view of the heel-stamp assembly of the Figure 3 seen from the front; the Figure 6 is an isometric view of a shaping pose of the invention seen in transparency; Figure 7 is an isometric view of a lower element of the shaping fixture of the invention; and the figure 8 is an enlarged view of the heel-stamp assembly positioned in the lower element of the shaping fixture of the invention. Embodiments of the invention

[0029] In reference to the Figures 1 and 2, there is shown a striking mechanism of a striking timepiece (such as a minute repeater, grand sonnerie, petite sonnerie, alarm clock) which comprises a first striking gong 1, a second striking gong 2, a first hammer 3 intended to strike the first gong 1 to produce a first note, to indicate the minutes for example, and a second hammer 4 intended to strike the second gong 2 to produce a second note, to indicate the hours for example.

[0030] With particular reference to figures 3 to 5, the first and second stamps 1, 2 are preferably wires or rods of round section, metallic, made for example from unhardened steel, gold, platinum, or brass. The first stamp 1 comprises a first end 1a secured to a heel 6 and the second stamp 2 comprises a second end 2a secured to the heel 6. Said heel 6 comprises a lower part and an upper part defined by a front face, a rear face and sides 6a, 6b. The first and second stamps 1, 2 respectively start from a side 6a, 6b of the heel 6, in opposite directions, forming a heel-stamp assembly.

[0031] The stamps 1, 2 are mounted on the heel 6 for example by embedding, locking with a screw, welding, brazing or even gluing. For this purpose, each side 6a, 6b of the heel 6 has an orifice 6c into which the stamp is inserted.

[0032] Referring again to the Figures 1 and 2, the striking mechanism also comprises a lever 8 linked to a support 10 by an articulation 11 along a single axis of rotation, of the flexible pivot type, and secured to a membrane 12 in order to be able to move said membrane 12 when the lever 8 pivots. It is the movement of the membrane 12 moved by the lever 8 which will generate an amplified sound. Such a mechanism is described for example in the publication WO 2021 / 078968 filed by the applicant.

[0033] The lever 8 is also integral with the heel 6, mounted on said lever 8 by means of screws 14. Thus, the gongs 1, 2 are integral with the lever 8 and are not fixed, via the heel, to the frame of the watch. However, it is quite obvious that the heel-gong assembly of the invention can also be used in a traditional manner, by being fixed directly to the frame or another suitable element of the timepiece.

[0034] The operation of the gongs and striking hammers in a striking mechanism of a striking timepiece such as a minute repeater is known to those skilled in the art, so that it does not require a detailed description here.

[0035] The first gong 1 is wound according to a first helix and the second gong 2 is wound according to a second helix, said first and second helices being wound in opposite directions from the heel, that is to say going for each in an opposite direction from the heel towards its free end, the winding directions and the pitches of the first and second helices being chosen as necessary in order to have no possible contact between the first and second gongs, whether in the rest position or in vibration during operation of the strike.

[0036] Preferably, the pitches of the first and second helices are chosen to be necessary and sufficient so as to have no possible contact between the first and second gongs while having the smallest possible distance between the gongs so as to have a limited Z-dimension, depending on the thickness of the movement. Indeed, the winding of the gongs in helices of opposite directions advantageously makes it possible to avoid any risk of contact between the gongs 1, 2 without having to provide additional safety.

[0037] According to the invention, as shown in the Figures 4 and 5, the first end 1a of the first stamp 1 and the second end 2a of the second stamp 2 are arranged in the same embedding plane P relative to the longitudinal plane of the heel 6 so as to be positioned on the sides 6a, 6b of said heel 6 at the same height. In addition, the first end 1a of the first stamp 1 and the second end 2a of the second stamp 2 are arranged symmetrically relative to the axial plane of the heel 6 so as to be opposite each other on each side of the heel 6.

[0038] In the example shown, in particular on the Figures 3 and 4 , stamp 1 is "descending", being wound in a counterclockwise helix starting from the right side of heel 6 as seen from its rear face, and stamp 2 is "ascending", being wound in a clockwise helix starting from the left side of heel 6 as seen from its rear face.

[0039] It is quite obvious that if the two stamps 1, 2 are fixed at the same height on one side of the heel 6, any stamp can be rising or falling, the other being wound in the opposite direction.

[0040] The coplanar embedding of the gongs 1, 2 on the heel 6 makes it possible to have the same distance between their embedding point and the articulation of the lever 8, so that the amplification of the vibrations of the membrane 12 will be similar for the two gongs 1, 2. There will therefore be no difference in sound level between the two notes produced by the gongs 1, 2.

[0041] Preferably, at least one of the first helix and the second helix is ​​a circular helix. More preferably, each of the first and second helixes is a circular helix, i.e., of constant winding radius. A constant radius means a variation in the radius of less than 15%, preferably less than 10% and more preferably less than 5%, related to the manufacture of the gong. This means that the winding radius of the gong is not intentionally modified to be increased or decreased.

[0042] Preferably, the first and second stamps 1, 2 each extend over less than one revolution.

[0043] It is also possible to use at least one cathedral gong, or even both, extending over more than one revolution, the configuration of the lever and its support then being adapted to allow the passage of the gongs. In this case, the gongs will be wound in helices of opposite directions and of increasing winding radius.

[0044] Advantageously, the first helix and the second helix have different winding radii, so that their lengths are different to produce different notes. This allows the advantageous use of timbres 1, 2 of identical radius.

[0045] Furthermore, the winding radii of the gongs are preferably chosen to go around the movement.

[0046] In a particularly preferred embodiment, the first helix and the second helix have the same pitch (in absolute value), so that the gongs 1 and 2 have turns which are always wound parallel to each other. As already described above, the pitch of the helices is chosen so that the gongs 1, 2 are sufficiently spaced from each other so as not to touch each other.

[0047] In a particularly advantageous manner, the first and second gongs 1, 2 each extend over less than one turn and are wound in a cylindrical helix of the same pitch.

[0048] In the example shown, the first gong 1 is wound according to a first cylindrical helix which has the smallest winding radius to generate the minute note, and the pitch of the first and second helices is identical. The diameter size is equal to the winding diameter of the second cylindrical helix which has the largest winding radius, here gong 2, so that the diameter size of gongs 1, 2 is limited.

[0049] Thus, as shown for example by the Figure 2, the two gongs 1, 2 wound in helices in opposite directions and with an identical pitch remain constantly parallel to each other, while vibrating freely and independently. The helically wound gongs allow each of the gongs to change plane immediately after their embedding so that one of the gongs 1 has its free end lower than the embedding plane P and the other gong 2 has its free end higher than the embedding plane P, as shown in Figure 5 . As a result, the parallel space which is constantly maintained between the gongs 1, 2 from their embedding point allows there to be no contact between said gongs, keeping the winding radii constant, even when the gongs make almost one turn and their free end returns close to the embedding point of the other gong, bypassing the movement, as shown in Figure 5 .

[0050] The heel-stamp assembly according to the invention preferably requires the use of a specific setting making it possible to give the stamps the desired helical shape, in particular during the tempering operation.

[0051] Such a shaping pose 20 is shown in the figures 6 to 8 The installation 20 comprises a lower element 20a and an upper element 20b, of generally cylindrical shape, and having a central opening 22, in particular to promote the circulation of heat during heat treatment.

[0052] The upper face 24 of the lower element 20a is of helical shape corresponding substantially to the helical shape here of the first descending stamp 1. The upper face 24 has an imprint 26 concentric with the central opening 22, and comprising a groove 26a corresponding substantially to the helical shape of the first stamp 1 and a hollow 26b corresponding substantially to the shape of the lower part of the heel 6. The groove 26a is interspersed with through holes 28 to promote the circulation of heat during a heat treatment. The depth of the groove 26a is substantially equal to the diameter of the stamp 1 intended to be housed therein so that said stamp 1 will arrive flush with the groove 26a. The upper face 24 of the lower element 20a being of helical shape, it comprises a shoulder 29 extending radially at the level of the hollow 26b.

[0053] The lower element 20a also has holes 30 for being assembled to the upper element 20b by means of screws 32.

[0054] The upper element 20b is generally symmetrical to the lower element 20a with respect to a plane perpendicular to the axis of the installation 20.

[0055] The lower face of the upper element 20b is of helical shape corresponding substantially to the helical shape of the second rising stamp 2. The lower face of the upper element 20b has an imprint concentric with the central opening, and comprising a groove corresponding substantially to the helical shape of the second rising stamp 2 and a hollow corresponding substantially to the shape of the upper part of the heel 6. The groove is interspersed with through holes to promote the circulation of heat during heat treatment. The depth of the groove is substantially equal to the diameter of the stamp 2 intended to be housed therein so that said stamp 2 will arrive flush with the groove. The lower face of the upper element 20b being of helical shape, it comprises a shoulder 34 extending radially at the hollow.

[0056] The lower 20a and upper 20b elements are arranged to fit together, in particular at the complementary shoulders 29 and 34, to form the mounting 20, their respective imprints being opposite each other, as well as the orifices 28 and the central opening 22.

[0057] The installation 20 also comprises a separation plate 36 arranged to be placed between the lower element 20a and the upper element 20b by being inserted between the two stamps 1, 2. Said separation plate 36 is a flexible plate having a helical shape arranged so that its lower face 36a is in contact with the first stamp 1 housed in the groove 26a of the lower element 20a and so that its upper face 36b is in contact with the second stamp 2 housed in the groove of the upper element 20b, as shown in figure 8 .

[0058] The separating plate 36 is guided and held by means of pins 38 provided on the lower element 20a.

[0059] The separation plate 36 also has cutouts to bypass the heel 6, the screws 32 and the pins 38.

[0060] When the stamps are wound in helices of the same pitch and in less than one turn, the thickness of the separation plate 36 is just less than the pitch of the helices so that it can fit perfectly into the space between the turn of the first stamp 1 and the turn of the second stamp 2.

[0061] The lower 20a and upper 20b elements of the installation 20 can be made of brass for example.

[0062] The heel-stamp assembly according to the invention is manufactured according to the method comprising the following steps: fixing the first end 1a of the first stamp 1 and the second end 2a of the second stamp respectively on a first 6a and second 6b side of the heel 6 in the orifices 6c, for example by welding, the first end 1a of the first stamp 1 and the second end 2a of the second stamp 2 being arranged in the same plane P relative to the heel 6 so as to be positioned on the heel 6 at the same height; carrying out a first heat treatment of the heel-stamp assembly, for example quenching;arranging the heel-stamp assembly in the shaping rest 20 by housing the first descending stamp 1 and the lower part of the heel 6 in the groove 26a and the hollow 26b of the impression 26 of the lower element 20a, by housing the second rising stamp 2 and the upper part of the heel 6 in the groove and the hollow of the impression of the upper element 20b, by arranging the separating plate 36 between the lower element 20a and the upper element 20 by inserting it between the two stamps 1, 2 in the space between the turn of the first stamp 1 and the turn of the second stamp 2, the separating plate 36 being guided by the pins 38, and by screwing the lower element 20a and the upper element 20b by means of the screws 32; performing a second heat treatment of the heel-stamp assembly inserted in its shaping rest 20, such as tempering; and removing the heel-stamp assembly from its shaping rest 20. ;

[0063] The resulting heel-stamp assembly can then undergo another step, such as a finishing treatment, such as polishing, in order to give it its final appearance.

[0064] The various elements of the shaping fixture 20 (impressions and separation plate) provided for guiding and holding the stamps during heat treatment, in particular tempering, allow, thanks to their helical shapes, to maintain a perfectly parallel space between each of the stamps 1, 2.

[0065] In particular, the separating plate 36, fitting perfectly between the turn of the first stamp 1 and the turn of the second stamp 2, its lower 36a and upper 36b faces are in contact with the stamp 1 and the stamp 2 respectively, over their entire length. Thus, the separating plate 36 prevents the stamps 1, 2 from touching each other and guides them in the shaping position 20 in a constant and progressive manner to give them their helical shapes in opposite directions, in cooperation with the corresponding impressions of the lower 20a and upper 20b elements. Thus, after the tempering operation, a heel-stamp assembly is obtained in which the stamps have the desired shapes, that is to say wound in helices in opposite directions and allowing no contact, one of the stamps being rising and the other falling, and preferably parallel.

Claims

1. A heel-gongs assembly for a chiming mechanism of a timepiece, comprising a heel (6), a first gong (1) comprising a first end (1a) integral with the heel (6) and a second gong (2) comprising a second end (2a) integral with the heel (6), said first and second gongs (1, 2) respectively starting from one side (6a, 6b) of the heel (6) in opposite directions, the first gong (1) being wound according to a first helix and the second gong (2) being wound according to a second helix, said first and second helixs being wound in opposite directions from the heel (6), the winding directions and the pitches of the first and second helixs being selected so as not to have any contact between the first and second gongs (1, 2), characterised in that the first end (1a) of the first gong (1) and the second end (2a) of the second gong (2) are placed in a same plane (P) with respect to the heel (6) so as to be positioned at the same height on the heel (6).

2. The assembly according to Claim 1, characterised in that at least one of the first helix and of the second helix, and preferably each of the first and second helixs, is a circular helix.

3. The assembly according to any one of the preceding claims, characterised in that the first helix and the second helix have different radiuses.

4. The assembly according to any one of the preceding claims, characterised in that the first helix and the second helix have the same pitch in absolute terms.

5. The assembly according to any one of the preceding claims, characterised in that the first and second gongs (1, 2) each extend over less than one turn.

6. A chiming mechanism of a timepiece, comprising a heel-gongs assembly according to any one of the preceding claims, and first and second hammers (3, 4) intended to strike the first and second gongs (1, 2) respectively.

7. The chiming mechanism according to Claim 6, characterised in that it comprises a lever (8) linked to a support (10) by an articulation (11) according to a single axis of rotation and integral with a membrane (12), said lever (8) being integral with the heel (6) of the heel-gongs assembly.

8. A timepiece comprising a chiming mechanism according to any one of Claims 6 and 7.

9. A method for manufacturing a heel-gongs assembly according to any one of Claims 1 to 5, comprising the following steps of: - fixing the first end (1a) of the first gong (1) and the second end (2a) of the second gong (2) respectively on a first side (6a) and a second side (6b) of the heel (6), the first end (1a) of the first gong (1) and the second end (2a) of the second gong (2) being placed in a same plane (P) with respect to the heel (6) so as to be positioned at the same height on the heel (6); - placing the heel-gongs assembly in a shaping fitting (20) which comprises a lower element (20a) having an impression corresponding to the helical shape of one of the gongs (1, 2) and to the shape of the lower part of the heel (6), an upper element (20b) having an impression corresponding to the helical shape of the other of the gongs (1, 2) and to the shape of the upper part of the heel (6), the lower element (20a) and the upper element (20b) being arranged to fit into one another, their respective impressions being opposite one another, and a separation plate (36) placed between the lower element (20a) and the upper element (20b) by being inserted between the two gongs (1, 2), said separation plate (36) having a helical shape arranged so that its lower face is in contact with the gong housed in the lower element (20a) and so that its upper face is in contact with the gong housed in the upper element (20b); - carrying out at least one heat treatment of the heel-gongs assembly inserted into its shaping fitting (20); - removing the heel-gongs assembly from its shaping fitting (20).

10. A shaping fitting (20) for manufacturing the heel-gongs assembly by the method according to Claim 9, characterised in that said shaping fitting (20) comprises a lower element (20a) having an impression corresponding to the helical shape of one of the gongs (1, 2) and to the shape of the lower part of the heel (6), an upper element (20b) having an impression corresponding to the helical shape of the other of the gongs (1, 2) and to the shape of the upper part of the heel (6), the lower element (20a) and upper element (20b) being arranged to fit into one another, their respective impressions being opposite one another, and a separation plate (36) arranged to be placed between the lower element (20a) and the upper element (20b) by being intended to be inserted between the two gongs (1, 2), said separation plate (36) having a helical shape arranged so that its lower face is in contact with the gong intended to be housed in the lower element (20a) and so that its upper face is in contact with the gong intended to be housed in the upper element (20b).