Clock glass fixing arrangement

Abstract

A timepiece comprising a case and a crystal delimiting an internal volume in which a miniature timepiece movement is arranged, the timepiece comprising a device for fastening the crystal to the case around the periphery of the crystal, the timepiece also comprising a device for connecting the crystal, the device comprising at least one support stud arranged in its internal volume in a fixed manner relative to the case and engaging with the crystal outside the periphery of the crystal fixed by said fastening device, in particular in the central region of the crystal, through contact with the underside of the crystal.

Description

[Technical field]

[0001] The present invention relates to an arrangement for fastening a watch crystal and to the watch itself, in particular an ultra-flat watch. The present invention also relates to a method for fastening a watch crystal, which belongs to the more general methods for manufacturing watches. [Background technology]

[0002] To produce watches with a small thickness, one must take into account the fact that the glass is prone to deformation under external pressure. In particular, reducing the thickness of a watch can depend on reducing the thickness of the glass and / or moving it closer to the movement and / or the hands. As a result, the effect of deformation of the glass becomes problematic, since the glass must be prevented from coming into contact with the movement or the hands, so as not to interrupt the running of the watch or damage the movement. Furthermore, it must be ensured that the weakened glass does not break when deformed.

[0003] Patent document 1 discloses a solution consisting of using the surface of the frame of a watch movement to form a stop that reduces the movement of the glass when it is deformed, in order to prevent the glass from coming into contact with the hands. The solution works in the extreme case of a significant deformation of the glass. In the normal configuration of the watch, such a stop has no effect. The solution therefore remains insufficient, although it allows to avoid certain extreme problems. For example, the glass can experience slight deformations, such as micro-vibrations, that come into contact with the stop or not, which requires the use of a glass that is sufficiently strong, in particular of an appropriate thickness. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Swiss Patent Application Publication No. 706978 Summary of the Invention [Problem to be solved by the invention]

[0005] The general object of the invention is to propose a solution for fixing the crystal to the case of a watch, which solution is particularly suitable for watches of small thickness. [Means for solving the problem]

[0006] Therefore, the invention is defined by the claims.

[0007] In particular, the invention is based on an arrangement for fixing a watch crystal, in a watch comprising a case, comprising a device for fixing the crystal to the case at the periphery of the crystal, the watch comprising a device for connecting the crystal at a distance from the periphery of the crystal or from the small watch case, in particular in the central region of the crystal, comprising at least one support stud which interacts with the crystal.

[0008] At least one stud may include a lower portion for mounting on the watch and an upper portion for contacting the underside of the crystal.

[0009] The arrangement may include a plurality of support studs, in particular between 1 and 10, which contact the glass in a central region of the glass.

[0010] The arrangement for fixing the crystal may comprise a plurality of support studs distributed substantially evenly over the central area of ​​the crystal and / or in the vicinity of parts of the movement that are intended to be located at a very short distance from the crystal, such as gears or hands.

[0011] The invention also relates to a watch comprising a crystal and a case, the watch including an arrangement for fixing the crystal as described above to the case.

[0012] The at least one support stud may be fixed to a bridge of the movement of the timepiece.

[0013] The at least one support stud may be fixed to a head of a screw on the bridge of the watch movement. The support stud may include an annular shape capable of interacting with a projection on the screw on the bridge of the watch movement.

[0014] The at least one support stud may be fixed so as to be adjustable in height so as to ensure that it is in contact with the glass.

[0015] The glass may comprise a thickness of 0.4 mm or less, or 0.35 mm or less, in particular between 0.2 and 0.4 mm, and / or the glass may comprise a diameter of 30 mm or more, or 30 mm or more, and / or a diameter of 45 mm or less, or 40 mm or less.

[0016] The watch may have a total thickness of 2mm or less, or 1.9mm or less, or 1.85mm or less.

[0017] The invention also relates to a method for fixing a watch crystal, comprising the steps of: Fixing the glass to the watch case around its periphery; The glass is connected over an area away from its periphery or away from the case, in particular in the central part of the glass, by means of at least one support stud which is in contact with the glass or is optionally fixed to the glass, The present invention relates to a method comprising the steps of:

[0018] Other advantages and features will emerge more clearly in the following description of particular embodiments of the invention, given by way of non-limiting example and illustrated in the accompanying drawings, in which: [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a top view of a timepiece according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a vertical cross-sectional view of a bridge of a timepiece according to an embodiment of the present invention. [Diagram 3]FIG. 3 is a vertical cross-sectional view of a support stud of a timepiece according to an embodiment of the present invention. [Figure 4] FIG. 4 is a perspective view of a screw of a timepiece according to an embodiment of the present invention. [Diagram 5] FIG. 5 is a perspective view of a support stud of a timepiece according to an embodiment of the present invention. [Figure 6] FIG. 6 is a perspective view of an assembly of a support stud on a timepiece screw according to an embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] To simplify the description, by convention, the term "horizontal" is used for any direction parallel to the watch crystal. The term "vertical" is used for any direction perpendicular to the watch crystal. The adjectives "upper" and "lower" are used to designate vertically related elements or surfaces located, respectively, on the side of the watch that is seen by the user, and on the opposite side, e.g., the side facing the wearer's wrist in the case of a wristwatch.

[0021] 1 shows a view from above of a timepiece 1 according to an embodiment of the invention. The timepiece 1 is a wristwatch including a case 2 including a lug 3 provided for fastening a small watch strap strand, not shown.

[0022] The case 2 comprises a base or plate, a case body and a bezel 4 arranged on the case body over the periphery of the case 2. Alternatively, other constructions of the case are also conceivable.

[0023] The watch 1 further comprises a crystal 10, which is practically invisible in FIG. 1 and which is fixed in a conventional manner by a fastening device, firstly at its periphery, on the case 2 and more particularly on the case body and / or the bezel 4. The first fastening means may be adhesive or mechanical. The bezel is fixed to the case body in a traditional manner, for example from the bottom of the small watch, by means of a screw, for example an octagonal head screw. The fastening device, which is therefore rather traditional, concerns the area around the crystal and a corresponding area on the small watch case.

[0024] The watch 1 further comprises a watch movement, fixed at the top by means of a bridge 5. The watch 1 further comprises at least one dial 6 and at least one hand 7. The case 2 and the glass completely or partially delimit an internal volume of the watch in which the watch movement is arranged.

[0025] 2 is a cross-section through a vertical plane of the watch 1. According to this embodiment, the watch is ultra-flat. Advantageously, the total thickness of the watch is less than or equal to 2 mm, or less than or equal to 1.9 mm, or less than or equal to 1.85 mm. The thickness may be greater than or equal to 1.7 mm.

[0026] As a result, firstly, the glass 10 is selected with a very small thickness, for example of the order of 0.3 mm. Advantageously, the thickness of the glass is equal to or less than 0.4 mm, or equal to or less than 0.35 mm. Advantageously, the thickness of the glass is equal to or greater than 0.2 mm, or equal to or greater than 0.25 mm. The thickness is preferably constant. Alternatively, the thickness may be variable, in which case the abovementioned values ​​are minimum or average values. The glass 10 further has a diameter equal to or greater than 30 mm, or equal to or greater than 35 mm. The glass 10 further has a diameter equal to or less than 45 mm, or equal to or less than 40 mm. The contour of the glass may be circular. Alternatively, the contour of the glass may have other shapes, such as square, rectangular, elliptical, etc. In all cases, the area of ​​the glass can be kept within the same values ​​resulting from the abovementioned diameter ranges. The glass 10 may be made of any known material, for example sapphire.

[0027] In addition, the crystal 10 is close to the movement in order to minimize the overall thickness of the watch, so that the space 11 between the underside of the crystal 10 and the top of the bridge 5 or hands 7 of the movement can be very small, for example less than 0.1 mm, as shown diagrammatically in Figure 2.

[0028] Due to the above mentioned dimensions, the glass 10, if fixed only by the above mentioned fixing device, is prone to deformation in a non-negligible manner, which deformation may be sufficient for it to come into contact with the movement, in particular with the bridge, which would cause a clamping of the gear train and / or the hands 7. For this reason, according to the present embodiment, the glass 10 is further held by one or more support studs 20, which come into contact with the underside of the glass 10. In other words, the glass 10 bears its weight on the support stud or support studs 20. Such a glass, due to its reduced thickness, is prone to undergo all kinds of vibrations and deformations, including those of very low amplitude, without necessarily coming into contact with the movement or the hands. These deformations tend to wear the glass and make it brittle. The support stud or support studs 20 make it possible to eliminate or reduce said phenomena.

[0029] According to the embodiment, the support stud 20 is advantageously arranged on the upper bridge 5 or plate of the movement. It extends vertically from said bridge 5 until it comes into contact with the underside of the crystal 10. Alternatively, the support stud may be fixed to another surface of the movement or of the watch. Preferably, the support stud is fixed away from the pins of the movement so as not to risk interrupting the rotation of the pins. The support stud therefore advantageously extends from a fixed surface without any connection to the rotating pins of the movement. The support stud is therefore separated from the rotating pins of the watch movement and from the moving elements of the watch movement. Such a support stud 20 is mounted in a fixed manner relative to the watch, more precisely relative to the small watch case 2, different from the parts of the watch movement such as the gear train or the pivot pins, and different from the elements which are prone to deformation.

[0030] The function of the support studs 20 is to complement the glass fixing devices provided around the periphery of the glass by forming all or part of a connecting device that is located in an area away from the periphery of the glass or away from the small watch case, i.e. away from the area around the glass and small watch case in which the glass fixing device is used. The support studs thus provide an additional glass retention element that is separate and complementary to traditional fixing devices.

[0031] Thus, the support studs are preferably located in the central area of ​​the glass 10. This central area can be defined as a disk of radius R / 2 or 3R / 4 of the glass, centred on the centre of the glass, where R is the radius of the glass. If the glass does not have a circular contour shape, a similar principle can be applied by considering it as a disk of the smallest radius in which it is inscribed. The support studs are thus located within the internal volume of the watch, and include a lower part that is fixed to the watch, such as the plate or bridge of the movement, and an upper part that is in contact with the underside of the glass.

[0032] The connection device, which includes one or more support studs, serves to prevent the glass 10 from deforming, at least at the support studs 20. The structure, in combination with the fastening device and the connection device, makes it possible to fix the glass in such a way that it is little, if at all, deformed and does not come into contact with the movement or the hands. More generally, the glass experiences little, if any, deformation.

[0033] According to the embodiment shown in figure 1, two support studs 20 are used. Advantageously, the connection device comprises a plurality of support studs 20, for example 2, 3, 4, 5 or 6, or more generally any number between 1 and 10.

[0034] Moreover, according to one embodiment, these support studs are advantageously distributed rather uniformly and at least partially away from the periphery of the crystal. Preferably, the support studs are located in the central part of the watch. For this purpose, the support studs 20 are advantageously located on a disk of radius R / 2 or 3R / 4 of the crystal 10, where R is the radius of the crystal. In other words, the central area is bounded by a circle of radius 3R / 4 or R / 2, where R is the radius of the circle in which the crystal 10 is inscribed. Alternatively or additionally, the support stud or support studs 20 may be located in the vicinity of the bridge 5 and / or the hand 7 whose surface is closest to the crystal 10. The support studs 20 may be identical or different.

[0035] According to a preferred embodiment shown in figure 3, the support stud 20 is fixed to a screw 11 of the movement, more precisely to the head 12 of the screw 11 fixed to the bridge 5 of the movement. For this purpose, the head 12 of the screw 11 is designed to include a first interaction device, for example a central pin, capable of interacting with the support stud 20.

[0036] In this regard, figures 4 to 6 illustrate an exemplary assembly of a screw 11 of a bridge of a movement with a support stud 20. Figure 4 shows the screw 11, which comprises at its head a cylindrical projection 12 extending around a longitudinal axis coinciding with the axis of the screw 11. A notch 13 is provided around the periphery of the head of the screw to allow the insertion of a tool and the intended actuation of the screw 11. Figure 5 shows the support stud 20, which has an annular shape and dimensions corresponding to the screw 11, in order to be able to interact with the head of the screw, as shown in figure 6, and to project beyond the head in terms of height by precisely filling the space between the screw 11 and the glass 10, as shown in figure 3, in order to come into contact with the glass 10.

[0037] In such an embodiment, it is possible to provide support studs 20 of different heights, which may be custom-made, in order to fill exactly the height between bridge 5 and glass 10. According to such an embodiment, the support studs 20 have a height calculated to correspond exactly to the distance between the movement and the glass, especially in cases where manufacturing gaps are small or negligible.

[0038] The support studs 20 are advantageously sufficiently rigid to prevent deformation of the glass, yet flexible enough not to form hard points on the glass that would pose a risk of damaging the glass, for this reason the support studs 20 are preferably made of a rubber material or a hard polymer, for example transparent silicone.

[0039] According to a variant embodiment, not shown, the positioning of the support stud 20 is height-adjustable. To this end, the support stud may comprise a lower mounting part that is screwed onto the movement, for example onto the bridge 5, in such a way that its height is variable depending on the screwing. As a variant, other mechanical height adjustment solutions are also envisaged. Such an embodiment makes it possible to compensate for any gaps and / or to guarantee contact with the glass in all cases at any desired pressure, even if production gaps are not negligible.

[0040] It is noted that in all cases the underside of the glass 10 may include a coating at the points of contact with the support studs 20. Such a coating may have a primary function of reinforcing the glass at the points of contact and a secondary aesthetic function of hiding the contact studs for the user of the watch.

[0041] The invention therefore relates to the above-mentioned arrangement for fixing the crystal 10 of a watch. The invention also relates to the watch itself. As mentioned above, the invention is particularly suitable for watches of very small thickness, in particular wristwatches.

[0042] It is additionally noted that the arrangement has been described as including at least one support stud in contact with the glass in order to maintain the position of the glass at a constant height and to prevent deformation when stresses occur on the upper surface of the glass. As implicitly emerging from the preceding description, such contact is formed when the glass is in a rest position, i.e. in a non-deformed position. In other words, the contact between the support stud and the glass is a permanent contact. As a variant, the support stud 20 may be fixed to the glass, for example by adhesive or mechanical means, forming a second device for fixing the glass.

[0043] In all cases, the support stud behaves differently from the stop described in patent application WO 2005 / 023333, which does not affect the glass except when it is significantly deformed. The support stud of the present invention acts as an element which holds the glass in its undeformed initial position and acts permanently on said glass to hold it in said initial position. The support stud therefore effectively contributes to the overall fixing of the glass in the watch.

[0044] The invention also relates to a method for fixing a crystal to a watch, - fixing the crystal 10 around its periphery to the watch case 2, - connecting the glass 10 with at least one support stud 20, which is in contact with or optionally fixed to the glass 10 over an area remote from the periphery of the glass fixed in the previous step, in particular in its central part, Includes steps.

[0045] Advantageously, the method includes the step of adjusting the height of at least one support stud 20 to ensure that the support stud is in contact with the glass 10 .

[0046] The method of fixing the glass is incorporated into the more conventional watch assembly and manufacturing methods.

Claims

1. A case (2) and glass (10) that divide the internal volume in which the watch movement is placed, A fixing device is provided around the glass (10) to secure the glass (10) to the case (2), A clock comprising a connecting device for connecting the glass (10), which includes at least one support stud (20), The support stud (20) is positioned within the internal volume so as to be fixed to the case (2), and interacts with the glass (10) through contact with the lower surface of the glass, away from the periphery of the glass fixed by the fixing device. clock.

2. The at least one support stud (20) is permanently in contact with the lower surface of the glass (10) or fixed to the lower surface of the glass (10) so that the glass is held in place. The clock according to claim 1.

3. The at least one support stud (20) includes a lower part for mounting onto the watch so as to be mounted to the case (2), The clock according to claim 1.

4. The clock (1) includes a plurality of support studs (20) that contact the glass (10) in the central region of the glass (10) which is demarcated by a circle of radius 3R / 4, where R is the radius of the circle in which the glass (10) is inscribed. The clock according to claim 1.

5. The plurality of support studs (20) are substantially uniformly distributed across the central region of the glass (10) and / or near the movement components that are intended to be located at a very short distance from the glass (10). The clock according to claim 4.

6. The at least one support stud (20) is fixed to the receiver (5) of the clock movement or to the clock plate. The clock (1) according to claim 1.

7. The at least one support stud (20) is fixed to the head of the screw (11) of the receiver (5). The clock (1) according to claim 6.

8. The at least one support stud (20) includes an annular shape that can interact with the projection (12) of the screw (11), The clock (1) according to claim 7.

9. The at least one support stud (20) is fixed in a height-adjustable manner so as to ensure that the at least one support stud (20) is in contact with the glass (10). The clock (1) according to claim 1.

10. The glass (10) includes a thickness of 0.4 mm or less, and / or the glass (10) includes a diameter of 30 mm or more. The clock (1) according to claim 1.

11. The clock (1) includes a total thickness of 2 mm or less. The clock (1) according to claim 1.

12. The at least one support stud (20) is separated from the pins of the watch movement or the moving elements of the watch movement. The clock (1) according to claim 1.

13. A method for fixing the glass (10) of a clock, The glass (10) is fixed to the watch case (2) around the glass (10). The glass (10) is connected using at least one support stud (20) that is in contact with or fixed to the glass (10) over an area separate from the periphery of the glass (10). A method including steps.

14. The at least one support stud (20) interacts with the glass (10) in the central portion of the glass (10) through contact with the lower surface of the glass (10), The method according to claim 13, including the step.

15. The at least one support stud (20) interacts with the glass (10) in the central region of the glass (10) through contact with the lower surface of the glass (10), The clock according to claim 1.

16. The circle that demarcates the central region of the glass (10) has a radius of R / 2. The clock according to claim 4.

17. The plurality of support studs (20) are substantially uniformly distributed in the vicinity of the gears or hands (7) of the movement, located at a very short distance from the glass (10). The clock according to claim 4.

18. The glass (10) includes a thickness in the range of 0.2 to 0.4 mm. The clock (1) according to claim 10.

19. The glass (10) includes a diameter in the range of 30 mm to 45 mm. The clock (1) according to claim 10.

20. The clock (1) includes a total thickness of 1.85 mm or less. The clock (1) according to claim 11.

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