CH722097A2 - Rigidly cased watch component and casing process - Google Patents

Abstract

The invention also relates to a method of fitting together.

Description

Technical field of the invention

[0001] The invention relates to a watch part with rigid casing of a watch movement and to a method of casing a watch movement in a watch part case.

Technological background

[0002] Casing a watch movement, that is, securing the movement within a case, is generally achieved using mounting flanges that fit into grooves on the inner circumference of the case, the assembly being held together by flange screws. However, this solution is relatively complex to implement due to the numerous parts and the various manipulations required for positioning the flanges and screws, which significantly impacts the productivity of such a casing solution.

[0003] Other casing solutions are also known, using an intermediate piece, such as a casing ring or an enlargement ring, positioned around the watch movement so as to hold it in place when a case back is screwed onto the case. Although this solution facilitates rapid movement mounting, it requires a space between the watch movement and the case to accommodate the casing ring, which limits the possible dimensions of the movement relative to the dimensions of the case.

[0004] Furthermore, various studies have shown that these casing solutions not only transmit the shock experienced by the case to the movement but can also amplify it. Consequently, there is a need to improve casing systems to minimize shocks to the watch movement, particularly to prevent damage, marking of components, or loss of connection between certain components.

[0005] A classic solution is to insert a damper, such as an elastomer ring, between the case and the movement, but this requires a large volume to be available.

[0006] Another solution proposed in document EP 1970779 consists of casing the movement using two superimposed casing rings in contact with each other, between which the watch movement is held. These two rings are themselves compressed between a portion of the case of the timepiece and the case back by means of an annular seal. One of the rings has a cutout for the passage of a winding stem. The annular seal is designed to axially and radially hold the lower casing ring when the case back is closed, and consequently the movement. However, such a casing creates play in the movement positioned between the two casing rings. Moreover, this play varies depending on the manufacturing tolerances of the casing rings and the rib of the watch movement, although an annular seal has been provided to ensure sufficient compression of the rings against each other.

[0007] Consequently, with such a casing solution, the shock resistances of watch movements are variable because in certain situations, the watch movement can move between the two casing circles, which has the effect of amplifying the shock suffered by the case at the level of the watch movement.

[0008] Consequently, there is a need for improvement of rigid casing watch parts to address at least one of the problems mentioned above.

[0009] There is also a need to improve a method of rigidly casing a watch movement in a watch case, and to propose such a method free from the limitations mentioned above.

Summary of the invention

[0010] The main objective of the invention is to provide a rigid casing for a watch part that allows for improved shock resistance of the watch movement housed in the case.

[0011] To this end, the invention aims to provide a timepiece comprising a case, a removable back mounted on the case, a movement and casing elements to rigidly hold the movement in an internal volume of the case.

[0012] According to the invention, the interlocking elements comprise:

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a first ring of interlocking supported against a bearing surface provided in the case;

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a second casing ring, said movement being held rigidly between the first casing ring and the second casing element via a peripheral rib of the clockwork movement, the first casing ring and the second casing ring being superimposed without direct contact with each other;

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a clamping element, separate from the removable base, in direct contact with the second ring of the case, the clamping element being arranged to axially compress the movement between the first ring of the case and the second ring of the case and to axially compress the first ring of the case against the bearing surface of the case.

[0013] The main objective of the invention is to provide a rigid casing for the watch movement that facilitates the operation of casing the watch movement in the case and minimizes the stresses and deformations experienced by the watch movement during an accidental shock to the watch part.

[0014] The casing proposed by the invention makes it possible to increase the rigidity of the casing and to ensure a play-free retention of the watch movement regardless of the manufacturing tolerances of the casing circles and the case.

[0015] The casing proposed by the invention also makes it easier to mount the watch movement in the case.

[0016] In addition to the characteristics mentioned in the preceding paragraph, the timepiece according to the invention may have one or more additional characteristics from among the following, considered individually or in all technically possible combinations:

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the clamping element is a clamping ring screwed into the case;

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the clamping element has on an external circumference a thread cooperating with a tapping made in the case, the tapping of the case for clamping the clamping ring being configured to receive the removable base by screwing;

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the watch part has the following axially superimposed: case, first casing circle, second casing circle, clamping element and removable back, the first casing circle and the second casing circle not being in contact with each other;

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the first ring of the socket has a shoulder cooperating with the span of the case;

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the first and second interlocking rings are made of rigid material with a Young's modulus greater than 50 GPa;

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the first casing circle covers the clock movement and supports a dial at the level of an upper face of the first casing circle;

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the dial is attached to the upper face of the first ring of the casing, preferably by gluing;

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the first casing circle covers the clockwork movement and in that one upper face of the first casing circle forms a dial.

[0017] The invention also relates to a rigid casing method for fixing a watch movement in a watch case according to the invention. The method comprises the following successive steps:

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a pre-assembly step of the first casing circle and the clockwork movement, so that an upper portion of the peripheral rib of the clockwork movement rests against an annular bearing surface of the first casing circle;

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a step of inserting the sub-assembly, formed in the previous step, into the case so that the first casing circle rests against a bearing surface of the case, the upper portion of the peripheral rib of the watch movement resting against an annular bearing surface of the first casing circle;

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a step of inserting the second casing ring into the case, the second casing ring resting on a lower portion of the peripheral rib of the watch movement, without direct contact with the first casing ring;

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a tightening step of the clamping element in the case so as to compress the stack consisting of the second casing ring, the watch movement and the first casing ring against the bearing surface of the case.

[0018] Preferably, the clamping step is carried out by screwing the clamping element into the case.

[0019] The assembly process can be a manual process, i.e. carried out by a natural person, or an automated process.

Brief description of the figures

[0020] The objects, advantages and features of the present invention will become apparent from reading the detailed description below, which refers to the following figures:

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Figure 1 is an exploded perspective view of a timepiece according to the invention comprising a case, a timepiece movement mounted in the case and casing elements to ensure the rigid fixing of the timepiece movement in the case;

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Figure 2 is a cross-sectional view of the timepiece according to the invention;

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Figure 3 is a bottom view of the timepiece illustrated in Figure 1; Figure 3 particularly illustrates the casing elements in position in the case;

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Figure 4 is a perspective view of the interlocking elements according to the invention;

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Figure 5 is a synoptic diagram illustrating the main steps of a casing process for a watch movement according to the invention.

[0021] In all figures, common elements bear the same reference numbers unless otherwise specified.

Detailed description of the invention

[0022] In the present application, the axial direction is a direction extending perpendicularly to a plane formed by the dial or the plate of the watch movement, referred to here as P1. A radial direction, on the other hand, is parallel to the plane P1 formed by the dial or the plate.

[0023] The terms “internal”, “external” are to be considered in reference to the center of the timepiece so that an internal face is closer to the center than an external face which is opposite to the center of the timepiece.

[0024] The terms “superior” and “inferior” are to be considered in a reference frame of a watch placed on its back as shown in Figure 2.

[0025] Figure 1 is an exploded perspective view of a watch part 100 according to the invention, with central axis B, comprising a case 10 configured to be closed on both sides by a removable back 12 and by a glass (not shown).

[0026] For example, the case 10 is made of metallic material, ceramic, polymer material or a mixture of different materials.

[0027] The timepiece 100 comprises a timepiece movement 20 housed in an internal volume 15 delimited by the case 10 and held in position in the case 10 by casing elements 30.

[0028] The watch movement 20 can be a mechanical, electromechanical or electronic movement.

[0029] The clock movement 20 has a central axis A perpendicular to a general plane P1. The central axis A of the clock movement 20 is parallel to or corresponds to the axis of rotation of the hands of the movement.

[0030] The central axis A of the clock movement 20 is parallel to or corresponds to the central axis B of the case 110.

[0031] A dial 40 is positioned above the clockwork movement 20.

[0032] As illustrated in Figure 2, which is a cross-sectional view of the watch part according to the invention, and in Figure 4, illustrating in perspective the casing elements 30, the casing elements 30 according to the invention comprise a first casing circle 35, which forms the upper element of the casing elements 30, bearing against a bearing surface 16 of the case 10. The bearing surface 16 is an annular bearing surface parallel to the plane P1 of the watch movement 20.

[0033] The first socketing circle 35 has a peripheral shoulder 36, configured to cooperate in support with the bearing surface 16 of the case 10.

[0034] The first socket ring 35 can be made of any rigid, non-elastomeric material, for example a metal or a synthetic material. Preferably, the first socket ring 35 is made of a rigid, non-elastomeric material having a Young's modulus greater than 50 GPa.

[0035] The first casing circle 35 is not split on its circumference, but has a partial opening 32 allowing the passage of a winding stem (not shown).

[0036] The perimeter of the watch movement 20 has on its external circumference a peripheral rib 21 bearing, at the level of a superior surface of the peripheral rib 21, against an annular bearing surface 37 provided at the level of a radially internal portion of the first casing circle 35.

[0037] The peripheral rib 21 can be continuous all around the clock movement 20 and be annular in shape or be made up of discontinuous segments of equal or unequal lengths around the clock movement 20.

[0038] The axial position of the watch movement 20 in the case 10 is determined by the dimensions of the first casing circle 35 and in particular by the axial position of the annular bearing surface 37, on which the watch movement 20 rests, in relation to the shoulder 36 of the first casing circle 35 resting against the bearing surface 16 of the case 10.

[0039] The casing elements 30 according to the invention comprise a second casing circle 34 which is superimposed under the first casing circle 35. The second casing circle 34 bears against the lower surface of the peripheral rib 21, and forces the peripheral rib 21 of the watch movement 20 against the annular bearing surface 37 of the first casing circle 35.

[0040] Thus, the upper face of the second casing circle 34 defines with the annular bearing surface 37 of the first casing circle 35 a housing in which the annular peripheral rib 21 of the watch movement 20 is clamped.

[0041] The watch movement 20 is therefore constrained between the first casing ring 35 and the second casing ring 34 when the watch part 100 is assembled. According to the invention, the first casing ring 35 and the second casing ring 34 are not in direct contact with each other, so that a space 39 is provided between the two casing rings 34, 35 when the watch part 100 is assembled.

[0042] Just like the first interlocking ring 35, the second interlocking ring 34 can be made of any rigid, non-elastomeric material, for example a metal or a synthetic material. Preferably, the second interlocking ring 34 is made of a rigid, non-elastomeric material having a Young's modulus greater than 50 GPa.

[0043] The two interlocking circles 34, 35 can be made of the same or different material.

[0044] The second casing ring 34 is not split on its circumference, but has a partial opening 38 for the passage of a winding stem.

[0045] The casing elements 30 according to the invention also include a clamping element 33, separate from the removable base 12, in direct contact with the second casing ring 34. The clamping element 33 forms the lower element of the casing elements 30 and is shaped to axially compress the watch movement 20, via the annular peripheral rib 21 between the first casing ring 35 and the second casing ring 34 and to axially compress the first casing ring 35 against the bearing surface 16 of the case 10.

[0046] The clamping element 33 is for example a clamping ring having on its outer circumference a thread configured to cooperate with a tapped hole 17 provided on an axial inner face of the case 10. The clamping ring 33 is mounted by screwing into the case 10 until it clamps the assembly formed by the casing rings 34, 35 and the watch movement 20 against the bearing surface 16 of the case 10.

[0047] As illustrated in figure 3, the clamping ring 33 has recesses 53 on its lower face allowing the introduction of a tool to facilitate screwing and tightening the clamping ring 33 in the case 10.

[0048] The casing elements 30 according to the invention, make it possible to maintain the watch movement 20 axially in the case 10 by compression between the two casing circles 34, 35 but also radially by the friction forces generated at the level of the annular bearing surface 37 of the first casing circle 35 and by the upper surface of the second casing circle 34.

[0049] Advantageously, the annular bearing surface 37 of the first casing ring 35 has a lateral wall forming a radial stop to the peripheral rib 21 of the watch movement 20, so as to limit as much as possible the radial movements of the watch movement 20 before tightening while ensuring a mounting clearance of the watch movement 20 inside the first casing ring 35.

[0050] The two mounting rings 34, 35 comprise a male or female positioning member cooperating with a complementary female or male positioning member to form a keying system. This keying system forms an anti-rotation device preventing rotation of the mounting rings 34, 35. Such a system also prevents the induction of a tightening torque on the watch movement 20 when tightening the clamping ring 33.

[0051] As illustrated in figures 1 and 4, the two interlocking circles 34, 35 include a female positioning member 54 cooperating with a male positioning member 55 (visible in figure 1) provided at the radially internal wall of the case 10.

[0052] The keying system also allows the two casing circles 34, 35 to be aligned so that the openings 32, 38 are aligned to form a passage for the winding stem of the timepiece 100.

[0053] Preferably, the threaded hole 17 in the case 10 also allows the removable case back 12 to be screwed in. An O-ring type annular seal 13 is compressed between the removable case back 12 and the case 10 to ensure the water resistance of the timepiece 100. The annular seal 13 is housed in a groove machined in the case 10. The annular seal 13 has, for example, a circular cross-section.

[0054] Preferably, the first casing circle 35 covers the watch movement and carries the dial 40.

[0055] The dial 40 is integral with the first casing circle 35 and is attached to the upper face 31 of the first casing circle 35.

[0056] The dial 40 is for example secured by gluing to the upper face 31 of the first casing circle 35 via an adhesive element 14.

[0057] The dial 40 is for example secured by welding, brazing or screwing onto the upper face 31 of the first ring of the casing 35.

[0058] The dial 40 can also be directly formed on the upper face 31 of the first casing circle 35.

Method for casing a watch movement into a watch part according to the invention

[0059] The invention also relates to a method for casing 400 a watch movement 20 into a case 10. To case the watch movement 20, a first step 410 consists of pre-assembling the watch movement 20 with the first casing ring 35 to form a sub-assembly. In this sub-assembly, an upper portion of the peripheral rib 21 of the watch movement 20 rests against the radially internal annular bearing surface 37 of the first casing ring 35. Once the two elements are pre-assembled, the hands are, for example, pressed onto the watch movement. As described previously, in this first step 410, the first casing circle 35 is pre-held with the clockwork movement 20 to form the sub-assembly, i.e. they are positioned together but the first casing circle is not secured to the clockwork movement 20.

[0060] Optionally, a preliminary step to the first 410 assembly step consists of securing the dial 40 to the first assembly circle 35 if the latter forms a support surface for the dial 40.

[0061] A second step 420 consists of inserting the sub-assembly formed by the first casing ring 35 and the watch movement 20, and optionally the dial 40, into the case 10, from the back side. The first casing ring 35 then rests against the bearing surface 16 of the case 10 and the watch movement 20 rests against the radially internal annular bearing surface 37 of the first casing ring 35.

[0062] A third step 430 consists of inserting the second casing ring 34 into the case 10 from the bottom side, so that the second casing ring 34 rests on the lower portion of the peripheral rib 21 of the watch movement 20. More particularly, a portion of the upper face of the second casing ring 35 rests on the lower portion of the peripheral rib 21 of the watch movement 20.

[0063] A fourth step 440 consists of tightening the assembly by mounting the clamping element 33, separate from the removable base 12, in the case so as to compress the stack consisting of the second casing ring 34, the watch movement 20 and the first casing ring 35 against the bearing surface 16 of the case 10, and to axially and radially lock the watch movement 20 in the case 10.

[0064] Preferably, the fourth clamping step 440 is achieved by screwing the clamping element 33 into the housing 10 through the cooperation of a thread with a tapped hole. For example, the clamping element 33 carries the thread and the housing 10 carries the tapped hole 17; however, the reverse is also possible without departing from the scope of the invention.

[0065] The casing elements 30 according to the invention make it possible to hold the watch movement 20 in position within the case 10 without the need to mount the removable back. The removable back was not required for the axial and radial support of the watch movement 20.

[0066] Generally, the invention has been described with operations performed by an operator. However, the invention is also applicable with an automated system or a robot; thus, the casing process for a watch movement according to the invention can be a manual or an automated process.

Claims (11)

1. A timepiece (100) comprising a case (10), a removable case back (12) mounted on the case (10), a movement (20), and casing elements (30) for rigidly holding the movement (20) within an internal volume (15) of the case (10), characterized in that the casing elements (30) comprise: - a first casing ring (35) bearing against a bearing surface (16) formed in the case (10); – a second casing ring (34), the movement (20) being rigidly held between the first casing ring (35) and the second casing element (34) via a peripheral rib (21) of the watch movement (20), the first casing ring (35) and the second casing ring (34) being superimposed without direct contact with each other; – a clamping element (33), separate from the removable case back (12), in direct contact with the second casing ring (34), the clamping element (33) being arranged to axially compress the movement (20) between the first casing ring (35) and the second casing ring (34) and to axially compress the first casing ring (35) against the bearing surface (16) of the case (10). 2. Watch part (100) according to the preceding claim, characterized in that the clamping element (33) is a clamping ring screwed into the case (10). 3. Watch part (100) according to any one of the preceding claims, characterized in that the clamping element has on an external circumference a thread cooperating with a tapping (17) provided in the case (10), the tapping (17) of the case (10) for clamping the clamping ring (33) being configured to receive the removable back (12) by screwing. 4. A watch part (100) according to any one of the preceding claims, characterized in that said watch part (100) axially comprises the following superposition: case (10), first casing ring (35), second casing ring (34), clamping element (33) and removable back (12). 5. A watch part (100) according to any one of the preceding claims, characterized in that the first casing circle (35) has a shoulder (36) cooperating with the bearing surface (16) of the case (10). 6. A watch part (100) according to any one of the preceding claims, characterized in that the first casing ring (35) and the second casing ring (34) are made of rigid material having a Young's modulus greater than 50 GPa. 7. A timepiece (100) according to any one of the preceding claims, characterized in that the first casing circle (35) covers the timepiece movement (20) and supports a dial (40) at the level of an upper face (31) of the first casing circle (35). 8. Timepiece (100) according to the preceding claim, characterized in that the dial (40) is integral with the upper face (31) of the first casing circle (35). 9. Timepiece (100) according to any one of claims 1 to 6, characterized in that the first casing circle (35) covers the timepiece movement (20) and in that an upper face (31) of the first casing circle forms a dial (40). 10. A method for casing (400) a movement (20) of a timepiece (100) into a case (10), according to any one of claims 1 to 9, comprising the following successive steps: a. a step (410) of pre-assembling the first casing ring (35) and the timepiece movement (20), such that an upper portion of the peripheral rib (21) of the timepiece movement (20) rests against an annular bearing surface (37) of the first casing ring (35); b. a step (420) of inserting the subassembly, formed in the previous step, into the case (10) so that the first casing ring (35) rests against a bearing surface (16) of the case (10), the upper portion of the peripheral rib (21) of the watch movement (20) resting against an annular bearing surface (37) of the first casing ring (35); c. a step (430) of inserting the second casing ring (34) into the case (10), the second casing ring (34) resting on a lower portion of the peripheral rib (21) of the watch movement (20), without direct contact with the first casing ring (35); d. a step (440) of tightening the clamping element (33) in the case (10) so as to compress the stack consisting of the second casing ring (34), the clockwork movement (20) and the first casing ring (35) against the bearing surface (16) of the case (10). 11. Method of casing (400) a movement (20) of a watch part (100) in a case (10), according to the preceding claim characterized in that the clamping step (440) is carried out by screwing the clamping element (33) into the case (10).