EP2989509A1

EP2989509A1 - Method and device for assembling a movement to a watch case

Info

Publication number: EP2989509A1
Application number: EP14709941.0A
Authority: EP
Inventors: Thierry Altenhoven; André Kaltenrieder; Stéphane Leoni
Original assignee: ETA SA Manufacture Horlogere Suisse
Current assignee: ETA SA Manufacture Horlogere Suisse
Priority date: 2013-04-24
Filing date: 2014-03-12
Publication date: 2016-03-02
Anticipated expiration: 2034-03-12
Also published as: JP2016528475A; CN105143999A; US9886004B2; HK1218448A1; JP6111376B2; US20160062315A1; CN105143999B; WO2014173582A1; CN203909480U; EP2989509B1

Abstract

A device for fixing a timepiece movement (3) to a watch case (1), comprising a peripheral attachment member of said movement (3) positioned in abutment on an axial bearing surface (11) of said case (1), said device being characterised in that it comprises thermoformed lugs (2) rigidly connected to said casing (1) having a mushroom shape (20) at the end of same having an axial retaining surface (21) acting as a rivet for holding said peripheral attachment member of the movement (3) against said axial bearing surface (11) of said case (1).

Description

Method and apparatus for assembling a movement in a watch case

The present invention relates to a method and a device for fixing a movement to a watch case.

In classical watchmaking, the fixing of the movement to the middle part is often effected by means of flanges and screws which are introduced into threads and place a thread of the movement against a shoulder of the middle part. While this type of fastener has the advantage of being reliable and reversible, it nevertheless has the disadvantage of being relatively complex to implement because of the different manipulations required for the screws and the flanges, which seriously affects the productivity. and is thus not suitable for the manufacture of watches intended to be produced on a large scale.

For fixing the movement to the housing, there are also known intermediate parts driven such as casing circles, which allow the rest to adjust small movements given and calibrated in larger housings. However, this method always has the disadvantage of requiring several mounting steps and additional parts for fixing. This type of fastening method thus allows greater flexibility, but no significant savings in costs.

Some solutions, such as that described in EP0770938 of the applicant, dissociate the axial positioning means from those of lateral positioning of the housing. The axial positioning is always achieved by affixing a collar of the movement frame on a shoulder of the middle part, but orifices and centering studs respectively formed in the bottom of the case and in the frame of the case. movement, and which are mutually engaged by sliding along the axis of movement, are provided for lateral positioning. Alternatively, pins are provided for coarse angular positioning of the movement before placing the time setting rod. However, this solution has the disadvantage of having to adjust the shape of the frame and also slows considerably the overall duration of assembly because of the many assembly steps required.

Furthermore, it is known from EP1365295 another type of attachment for electronic modules using hooks assembled at the bottom of a housing with a retaining plate. When the module, which comprises a plurality of recesses with edges that are provided with shoulders, is introduced into the housing, the hooks operate in the manner of a harpoon for pressing the module against the bottom of the housing. Although it is efficient and also facilitates any disassembly operations, this solution also requires a very special frame structure for the module to be assembled, which must be provided with through holes to allow the introduction of the fastening hooks, and requires elsewhere a step of assembling an additional piece to secure these fastening hooks to the bottom, such as for example by heat sealing the retaining plate on the guide pins according to the preferred embodiment described. This also has the effect of slowing down the rate of production.

There is therefore a need for a method and apparatus for mounting a motion to a housing free of these limitations.

An object of the present invention is to provide a method and a device for fixing a movement to a housing alternative to the known solutions and requiring no screws, flanges or casing rings.

These objects are achieved by means of a method for fixing a watch movement to a watch case, a device for fastening the peripheral movement being brought into abutment on an axial bearing surface of the case, characterized in that it includes a step of thermoforming tenons secured to the housing so as to locally deform the end of each post and form a rivet having an axial retaining surface vertically retaining the peripheral fastening member of the movement against the axial bearing surface of the housing.

These objects are also achieved by means of a device for fixing a watch movement to a watch case, comprising a peripheral fastening element of the movement positioned in abutment on an axial bearing surface of the case. The device is characterized in that it comprises thermoformed tenons integral with the housing, having a mushroom shape at their end having an axial retaining surface acting as a rivet for holding the peripheral fastening element of the movement against the bearing surface. axial of the housing ..

These goals are also achieved through a middle and a movement taken separately for the implementation of the method of assembly, the middle part being characterized in that it comprises at least 6 thermoformable fastening lugs having a diameter of between 1 and 2 millimeters to form fixing rivets adapted for the weight of a movement, and the movement corresponding to a preferred embodiment in which the peripheral fastening element consists of a collar provided with a plurality of orifices, or in a plurality of ears, the holes of the ears or the collar being provided for the insertion of the tenons.

An advantage of the proposed solution is to facilitate assembly operations, increase the production rate and minimize production costs. The thermoforming operation of the tenons for the final fixation of the movement can be performed very quickly without requiring tedious handling, which increases productivity. Furthermore, the movement can be assembled on the dial side, which avoids a reversal operation as for a conventional mounting by the bottom of the housing. Another advantage of the proposed solution is that it is compatible with a large number of types of movements, since it requires no adaptation of the frame, but only an adjustment of peripheral fixing parts. It is compatible in particular with movements both provided and not provided with net.

Furthermore, according to a particularly advantageous preferred embodiment, no additional fastener is required, all fasteners being directly integrated with the movement and the housing.

Other advantages will emerge from examples of implementation of the invention indicated in the detailed description and illustrated by the appended figures in which:

Figure 1 illustrates a top view of a movement assembled in a housing according to a preferred embodiment of the invention;

Figure 2 illustrates a sectional view along the axis A-A of the movement and the housing according to the preferred embodiment of the invention of Figure 1;

Figure 3 illustrates a detailed view of the attachment of the movement to the middle part according to the preferred embodiment of the invention illustrated in Figure 2;

Figure 4 shows a sectional view along the axis C-C corresponding to the axis 3 hours - 9 hours of the watch of a complete watch comprising a movement assembled to the housing according to the preferred embodiment of Figure 1;

Figure 5 shows a top view of a movement assembled in a housing according to an alternative embodiment of the invention;

Figure 6 shows a sectional view of an alternative method of attachment for movement in a caseband according to an alternative embodiment of the invention; Figure 7 shows a sectional view of an alternative method of attachment for movement in a caseband, using tenons arranged on removable parts.

In the following, reference will be made to FIGS. 1, 2 and 3, which illustrate various views of a preferred embodiment for the device for assembling movement 3 in a housing 1 according to the present invention, as well as FIG. showing an integral watch using this assembly device. The movement 3 there is no thread for its attachment, but comprises, as a fastening element, a collar 32 at its periphery. This flange 32 comprises a plurality of orifices 321 - ten in total as shown in FIG. 1 - intended to receive tenons 2. This preferred number of tenons 2 is provided to receive the plate of a movement 3 having a mass of up to at 20 grams when made of plastic. Other parameters relating to the behavior of the movement such as in particular their diameter and the surface of the axial retaining surface 21 that they confer are discussed later with the aid of FIG.

According to this preferred embodiment, the flange 32 used as a peripheral fastening element of the movement 3 is preferably made of material with the remainder of the movement 3, which makes it possible to manufacture the whole directly by molding, without the need for an assembly operation. additional dedication for this fastener. Similarly, the orifices 321 can be obtained directly without requiring a specific drilling operation. Similarly, the arrangement of the pins 2 directly on the middle part 10, makes it possible to save an additional assembly or machining step of these fastening elements of the housing. In this case, both the movement 3 and the middle part 10 are preferably made of plastic material, whose deformation properties are appropriate for the thermoforming operation, and in order to allow a simple molding operation in particular by injection for their manufacturing. Nevertheless, it will also be possible to use fasteners peripherals, such as the flange 32, made of a different material such as metal, ceramic, or even wood.

According to the invention, the thermoforming of the end is provided to perform a function similar to that of a riveting, that is to say without necessarily securing the axial retaining surface 21 formed on the end of the post 2 of the axial bearing surface 1 1. However, it is also sometimes referred to a heat sealing operation which, depending on the materials used for the middle 1 and the posts 2, does not necessarily imply their mutual attachment to their contact surfaces. Those skilled in the art will however understand that such a possible attachment of the fasteners is not detrimental to the implementation of the present invention.

In FIG. 1, movement 3 is shown on the dial side, while the latter is not yet assembled on its upper face (FIG. 4 described in detail later illustrates a sectional view of a watch integrally assembled with the dial. 7 affixed to the movement 3 and the elements closing the housing 1 such as the bottom 14 and the ice 9). A ring of the dates 37 can be distinguished inside the flange 32, as well as two series of 5 fastening lugs distributed on either side of a diameter on which parallel polarizers 13 are arranged. According to the embodiment of FIG. preferred embodiment illustrated, the polarizers 13 are male elements also arranged directly on the middle part 1 0. Their machining is more accurate than that of the pins 2 to ensure the positioning and the angular locking of the movement 3 in a given position; the movement 3 is thus introduced by the dial side by threading the tenons 2 in the orifices of the flange 32, and parallel the polarizers 1 3 in corresponding female elements, preferably arranged on the periphery of the movement 3, as here on the flange 32 .

FIG. 2 illustrates a sectional view along the axis AA represented in FIG. 1, of two diametrically opposed posts 2 after assembly. movement in the housing 1, that is to say after the thermoforming operation. The housing 1 is shown here without its bottom 14 - visible in Figure 4 - that is to say only through the middle part 10, on a prominent portion 1 00 of which are arranged the tenons 2. This mode embodiment is advantageous because it allows to free space between the bottom of the movement 3 and the bottom of the housing 14 to accommodate other parts, such as for example an oscillating mass 36 as shown in Figure 4, while it is not possible to superpose parts at the upper face of the movement 3 where is usually only positioned the dial and no visual impediment for reading the time is possible. According to an alternative embodiment, however, one could also consider forming the pins 2 on another part of the housing 1, such as directly on the bottom 14 visible in Figure 4; this variant would however require positioning the flange 32 for fixing lower to minimize the height of the pins 2 and would be less effective in terms of centering if the bottom is integrally formed with the middle part 1 0.

Figure 2 shows the pins 2 while they have already been deformed by the thermoforming operation and thus allow to retain the flange 32 vertically along the axis ZZ of the barrel 30 of the needles of the watch; the detail of the assembly part surrounded by the circle B is represented by FIG. 3. On the upper face of the movement, the ring of the dates visible in FIG. 1 can always be distinguished, while it can be seen that the outer side wall 33 of the movement, and a portion of the inner side wall 1 2 of the housing 1, against which the outer side wall 33 is in contact or not. The bottom of the movement 35 does not come to rest on the bottom 14 of the housing 1, not shown in this figure, the movement 3 being brought into abutment on the axial bearing surfaces January 1 of the middle part 10 on which the surface lower flange 32 come to bear after the holes 321 thereof have been engaged on the pins 2 fixing. FIG. 3 shows the detail of the attachment of the movement to the casing 1 according to the preferred embodiment of FIG. 2, with the flange 32 resting on the axial bearing surface 1 1 of the middle part 10, arranged here on a part The tenon 2, engaged in the orifice 321 of the collar 32, is deformed by the thermoforming operation and has a mushroom shape 20 at its upper end, which makes it possible to provide a protrusion 1 00 inside the middle 1 0. axial retaining surface 21 on its underside for vertically retaining the flange 32 pressed against the axial bearing surface 1 1 of the middle part 10. The fungus 20 thus formed thus acts as a rivet for the peripheral portion of the attachment of the movement that forms here, the flange 32. As can be seen in this figure, there is not necessarily any contact between the external lateral wall 33 of the movement and the internal lateral wall 12 of the middle part, which makes it possible to increase enter the machining tolerances at this level, the centering of the plate and the movement 3 being preferably sufficiently made by the polarizers 1 3. The difference between the diameter of the orifice 321 of the flange 32 and the diameter post 2 is however preferably chosen to be less than 0.2 mm, so as not to reduce too much the contact surface between the lower face of the mushroom 20 and the axial bearing surface 21.

It may also be noted in this figure that the ratio between the radius of the post 2 and that of the mushroom 20 is approximately equal to 1 .5, and that the thickness of the mushroom 20 is substantially equal to the radius of the post 2. The embodiment The preferred embodiment of FIG. 1 uses such a mushroom shape 21 for a post 2 having a diameter of preferably between 1 and 2 mm, which makes it possible to withstand a movement 3 having a mass greater than 10 grams with a greater number of plastic posts. equal to 6. Thanks to the hyperbolic decrease of the stresses exerted on each tenon 2 according to their number, it will also be possible, for the sake of economy, to limit the number of tenons 2 as being at most equal to 1 5. to limit as much as possible the number of tenons 2, it is also possible to play on the material which constitutes them in choosing a more rigid than the plastic usually used in watch frames.

FIG. 4 shows a view of an integral watch using the method and the assembly device described in FIGS. 1 to 3 above, along the cutting axis CC illustrated in FIG. 1 corresponding to the axis 3h-9h which does not cross the studs 2 thermoformed contrary to the cutting axis of Figures 2 and 3. There is always the flange 32 attachment, which takes the form, in this angle, an annular shoulder, coming to rest on the surface 1 on the axial surface arranged on the upper surface of the protruding portion 1 00 internal of the middle part 10. On the upper face of the movement on the dial side we still distinguish the ring of the dates 37, but this time it is surmounted by a dial 7 above which the hands of the second 301, minutes 302 and hours 303, driven by the central barrel 30 of the movement 3, rotate, and which is furthermore provided with a window 71 showing the current date values. . The peripheral portion 72 of the dial is clamped by the lens 9, surmounted by a bezel 91, and which is assembled at a bearing 15 of the caseband 10, for example for example by means of ultrasonic welding. The middle 10 is traversed by a rod 6 conventionally comprising a ring 61 at its distal end to be easily manipulated by the user. The housing 1 is closed by a bottom 14 above which is housed an oscillating mass 36 coupled to the movement 3 for its automatic winding, and whose lateral flanges 361 go up to the lower level of the prominent portion 100 of the middle part 10 .

The device and the proposed method of attachment thus apply to any type of watch, whether quartz or totally mechanical.

Other variants for fixing are possible to achieve the peripheral fastening element, which may have for example fastening lugs 31 in place of the flange 32 with a hole to accommodate the studs 2. Such a variant is illustrated in FIG. figure 5 which shows a top view similar to Figure 1 of a watch which we see more clearly the mushroom shape 20 acting as a rivet at their end and the shape of the ears 31 at most just fit the shape of the post 2. The ears 31 are in this cases simply intended to have a central fixing hole in which the pins 2 must be introduced before the thermoforming operation, as well as lower and upper bearing surfaces for their axial retention along the vertical axis corresponding to that of the barrel 30 needles. They thus make it possible to reduce the volume of material required to form the element for fixing the movement and thus to optimize costs. According to this alternative embodiment, the locking of the rotational degree of freedom is preferably always achieved by means of polarizers 13. It is possible otherwise to distinguish in this FIG. 5, in addition to the ring of calendars 37, on the periphery of the movement 3, the gripping ring 61 at 3 o'clock on the casing 1.

FIG. 6 illustrates another alternative embodiment for the method and the device for fixing a movement, according to which the movement 3 again comprises a thread 34, unlike those of the preferential embodiment which were not there, and a retaining ring 4. The thread of the movement 34, which is used as a fixing element, the bottom surface 341 of the thread then being brought into abutment against an axial bearing surface 1 1 of the middle part 10, then the retaining ring 4, comprising a plurality of holes 41, is threaded on the pins 2 preferably of material with the middle 1 0. The thermoforming operation of the pins 2 form fungi 20 above the retaining ring 4 and the axial retaining surface 21 thus generated allows to press the retaining ring 4 against an upper surface 342 of the thread 34 of the movement, which in turn remains tight against the axial bearing surface 1 1 of the middle part 10. The advantage of this alternative variant is that it allows to use a traditional movement 3 with net 34; the disadvantage is that it requires the use of an additional piece - the retaining ring 4 - so that the elements of fixation are no longer directly integrated respectively to the housing 1 and the movement 3.

FIG. 7 illustrates another alternative embodiment for the invention concerning the pins 2, which are arranged on plugs 5 provided with ridges 51 designed to facilitate their driving in holes in the casing 1, preferably in the middle part 10. A such modular arrangement plugs dissociates the selected material for the middle 10 of such selected for the tenons; it would thus be possible for example to choose plastic plugs 5 while the middle part 10 would be metal. It will further be understood that this variant of removable posts 2 is compatible with all the other embodiments previously described with reference to FIGS. 1 to 6.

Claims

1. Method for fixing a watch movement (3) to a watch case (1), a peripheral fastening element of said movement (3) being brought into abutment on an axial bearing surface (1 1) of said case (1), characterized in that it comprises a step of thermoforming tenons (2) integral with said housing (1) so as to locally deform the end of each tenon (2) and form a rivet comprising a retaining surface ( 21) axially holding said peripheral fastening member of said movement (3) against said axial bearing surface (1 1) of said casing (1).

2. Method for fixing a clockwork movement (3) to a watch case (1), said movement (2) being introduced on the dial side (7).

3. Method for fixing a watch movement (3) to a watch case (1) according to claim 1 or 2, characterized in that it comprises a preliminary step of inserting said pins (2) into through holes arranged in said peripheral fastener before the thermoforming step.

4. Device for fixing a clockwork movement (3) to a watch case (1), comprising a peripheral fastening element of said movement (3) positioned in abutment on an axial bearing surface (1 1) said housing (1), said device being characterized in that it comprises thermoformed tenons (2) integral with said casing (1) having a mushroom-shaped (20) at their end having an axial retaining surface (21) acting as rivet for holding said peripheral fastening member of the movement (3) against said axial bearing surface (1 1) of said casing (1). .

5. Device for fixing a clockwork movement (3) to a housing (1) according to claim 8, characterized in that a polarizer (13) is arranged on a middle part (10) for the angular positioning of said movement (3) in said housing (1).

6. Device for fixing a watch movement (3) to a housing (1) according to one of claims 4 or 5, characterized in that it comprises a retaining ring (4), said movement ( 3) further comprising a thread (34), said axial retaining surface (21) of said studs (2) plating said retaining ring (4) against an upper surface (342) of said net (34).

7. Carrure (10) for the implementation of the fixing method according to claims 1 to 3, characterized in that it comprises at least 6 pins (2) of thermoformable fastening each having a diameter of between 1 and 2 millimeters .

8. Carrure (10) according to claim 7, characterized in that said pins (2) are formed of material with said middle part (10).

9. Carrure (10) according to claim 7, characterized in that said pins (2) are arranged on a removable cap (5) driven into said housing (1).

1 0. Movement (3) for the implementation of the fixing method according to claims 1 to 3, characterized in that said peripheral fastening element is formed by a flange (32) provided with a plurality of orifices ( 321) or a plurality of ears (31).

1 1. Movement (3) according to claim 10, characterized in that said flange (32) or the lugs (31) are formed of material with said movement (3).