FR3072790A1 - ALLEGE DISC OF WATCH PIECES - Google Patents

Abstract

Lightened display disc (la) of a timepiece comprising in its center an orifice (2) intended to drive a cannon mounted on a motor shaft of a watch movement, said disc (1a) being provided by a rim (3) device whose inner periphery is connected to at least one junction wall (4) extending towards the center (2) of said disk (la) by a perforated central wall (5), while the rim (3) and the perforated wall (5) are located in two parallel planes forming a clearance.

Description

LIGHT DISC OF WATCHMAKING PARTS

The present invention relates to an analog display device of a timepiece comprising at least one lightened display disc, a timepiece comprising the display device according to the invention, as well as a disc of lighter display as such.

A timer mobile is conventionally formed of three concentric barrel shafts, namely a first peripheral hollow shaft for the pivoting of the hours, a second intermediate hollow shaft for the pivoting of the minutes and a central shaft, of small diameter, for the pivoting of the seconds.

Usually, each concentric shaft of the watch movement is intended to initiate a pivoting movement, via a barrel, of a hand corresponding to the indication of the hours, minutes and seconds.

A system for transmitting or driving a movement transmits the energy accumulated in the barrel to a toothed wheel, more precisely to three wheels corresponding to the hours, minutes and seconds wheels.

Document FR15 58258, of which the applicant is the holder, discloses in particular an analog display device comprising concentric discs for displaying the hours, minutes and seconds.

During an impact, the kinetic energy stored and transmitted by the needles to the movement is relatively low, because the needles have a low weight and therefore a low moment of inertia, which is not the case with discs of display.

Thus, the wheels, their notched teeth, or the barrel, or even the watch movement can be damaged by the energy transmitted by the display discs and cause a malfunction of the timepiece, rendering it unusable.

The present invention provides a timepiece, an analog display device, as well as lightened display discs, making it possible to overcome the aforementioned drawbacks.

Thus, a lightened display disc according to the invention, of a timepiece, comprises in its center an orifice intended to drive out a cannon mounted on a motor shaft of a watch movement, the disc being presented by a rim peripheral whose inner periphery is connected to at least one junction wall extending towards the center of the disc by a perforated central wall, while the rim and the perforated wall are located in two parallel planes forming a clearance.

According to one embodiment, the perforated wall is presented by reinforcing spokes connecting the center of the disc to the wall (s) of junction.

According to the previous embodiment, the lightened display disc comprises a number of reinforcing spokes greater than or equal to six.

According to one characteristic, the flange is connected to junction walls which are extended by the reinforcing spokes.

According to an additional characteristic, the peripheral rim comprises regularly distributed perforations.

According to the preceding characteristic, the perforations are of triangular shapes, while they are arranged in staggered rows.

According to an additional characteristic, the constituent material of the lightened display disc is stainless steel.

The invention also relates to a device for displaying a timepiece comprising at least one lightened display disc.

According to one embodiment, the device comprises at least two lightened display disks of two different and concentric diameters, while a lightened minute display disk is nested in the clearance of a lightened hour display disk .

According to one characteristic, a peripheral rim of at least one lightened display disc comprises at its upper surface a label.

According to one embodiment, the display device comprises a disc-barrel for displaying the seconds consisting of a cannon which has a T-shaped cross section, namely consisting of an upper surface, a bore centered on the latter and a lower annular peripheral rib, centered along the axis passing through the bore.

It should also be noted that the invention relates to a timepiece comprising the display device described above.

Other characteristics and advantages of the invention will emerge from the description which follows with reference to the appended drawings which are given only by way of nonlimiting examples.

Figure 1 is a top view of a timepiece according to an embodiment of the invention.

Figures 2 to 5 are views of display disks, according to one embodiment.

Figure 2 is a top view of a lightened hour display disc.

FIG. 3 is a sectional view along A-A of FIG. 2.

Figure 4 is a top view of a lightened minute display disc.

Figure 5 is a sectional view of a disc-gun display seconds.

Figure 6 is a sectional view of Figure 1 along A-A.

Thus, a display device (9) of a timepiece according to the invention, comprises at least one lightened display disc (la, lb), advantageously comprises the nesting of two discs (la, lb) concentric light displays intended to be mounted each on a motor shaft of a watch movement.

A display device (9) is provided by at least one lightened hour display disc (la), preferably a lightened minute display disc (lb) and advantageously a barrel seconds display disc (11 ).

According to one embodiment, the display device (9) comprises a lightened display disc for the hours (la).

According to another embodiment, the display device (9) comprises a lightened hour display disc (la) and a lightened minute display disc (lb).

According to the illustrated embodiment, the display device (9) comprises a lightened hour display disc (la), a lightened minute display disc (lb) and a canon display disc for seconds ( 11).

Note that a light display disc for minutes (lb) or hours (la) includes an opening (2) in its center. This orifice (2) is intended to be fixed to a barrel, such as by crimping or welding, itself intended to be driven out on a motor shaft of a watch movement, in order to be pivotally mounted.

Let us add that a disk (la, lb) is presented by a peripheral rim (3) connected by at least one junction wall (4) oriented perpendicular or substantially perpendicular to the rim, while the junction wall (s) ( 4) extends (nt) to the center of the disc (la, lb) by a perforated central wall (5).

Note that at least one junction wall (4) connects the flange (3) to the perforated central wall (5) so that the flange (3) and the perforated central wall (5) are located in two parallel planes .

Note that the presence of at least one junction wall (4) forms a central clearance (7) intended for the placement either of a second lightened display disc (lb) of smaller diameter or of a barrel disc ( 11) display, as explained in more detail in the following description.

The Applicant in order to limit the weight of the discs (la, lb), in order to limit their moments of inertia and thus the stresses exerted against the barrels, the wheels and the shafts of watch movements, in particular in the event of impacts, s 'is endeavored to develop perforated disc structures by removal of material.

Surprisingly, in an approach to optimize the weight of the parts, the Applicant has discovered that the production of a structure of a perforated central wall (5), made it possible to obtain an elasticity effect of the discs, absorbing the stresses against the parts connected to these discs in the event of impact.

Indeed, the presence of a perforated central wall (5), makes it possible to obtain an effect of elasticity of the disc, bringing an elasticity of at least the peripheral rim (3) relative to the center of the disc.

From the point of view of the industrial production of these discs, it is essential to obtain a disc structure suitable for the production process to be viable, namely to obtain the minimum amount of scrap.

For the production of metal parts, it is common in the field of watchmaking to use laser cutting techniques for metal plates.

However, cutting a complex piece of small thickness and relatively large diameter on the scale of a timepiece, requiring optimal coplanarity, is difficult.

This difficulty is caused by the torsion of the parts when cutting the outer periphery of the discs, due to the weight of the metal plate still connected to the part to be produced.

The difficulty of this operation is to find a compromise between the weight and a structure retaining its flatness, namely a sufficiently rigid disc structure.

Thus, the removal of too much material makes the piece to be cut too fragile, which is liable to be twisted during the cutting process.

In addition, the production of patterns that are too complex also generates too much scrap, which is unacceptable.

According to one embodiment, the perforated central wall (5) is provided by reinforcing spokes (6) connecting the center of the lightened disc to at least one junction wall (4).

According to the illustrated embodiment, the flange (3) is connected to junction walls (4) which are extended by spokes (6) of reinforcement connecting the center of the disc (1a, 1b) of lightened display.

According to the previous embodiment, the extension of a reinforcing spoke (6) by a junction wall, connecting the center of the disc (la, 1b) to the flange (3), increases the elasticity properties of the disc, increasing thus the impact resistance of the timepiece.

According to the illustrated embodiment, the number of reinforcing spokes (6) is six.

It has been found that a number of spokes (6) of between three and five gives good results in terms of impact resistance of timepieces, but their production generates too much scrap, reaching a scrap rate of the around 40%.

This significant scrap rate is caused by the low torsional resistance of these discs. Their twisting, caused by the weight of the metal plate when cutting it, thus becomes permanent.

Thus, an optimization of the weight and an optimization of the rate of production of parts retaining a flatness of the discs (la, 1b), are obtained with a number of spokes (6) of reinforcement greater than or equal to six.

According to an additional characteristic, a lightened display disc (la, 1b) is made of austenitic stainless steel, while the disc (11) is advantageously made of aluminum.

According to the preceding characteristic, it should be recalled that a lightened display disc (la, lb) has a very small thickness, the latter must have optimal flatness to ensure proper operation of the timepiece, the metal constituting these discs must be sufficiently rigid, on the contrary aluminum is a metal too soft for the application of the present invention.

According to an additional characteristic, the peripheral rim (3) comprises perforations (8) regularly distributed over its surface.

According to the illustrated embodiment, the perforations (8) are triangular in shape, while they are arranged in staggered rows.

This staggered arrangement allows optimization of the weight-stiffness ratio of the rim (3), helping to reduce the weight of a disc (la, 1b).

Add that a disc-barrel (11) for displaying the seconds consists of a cannon which has a T-shaped cross section, namely consisting of an upper surface, a bore centered on the latter and a lower annular peripheral rib, centered along the axis passing through the bore.

Thus, as previously introduced, a display device (9) according to the invention comprises at least one lightened hour display disc (la) and a lightened minute display disc (1b) located in the clearance of the lightened hours display disc (la).

According to the embodiment illustrated in FIG. 5, the display device further comprises a barrel disc (11) for displaying the seconds located in the clearance (7) of the lightened minute display disc (1b).

According to one characteristic, the discs (la, 1b) and the barrel disc (11) have a dimension, namely a diameter suitable for being arranged with each other so that lateral spaces ( 12) are formed between them, namely according to embodiments, a lateral space (12) between the hour disc (la) and the minute disc (1b), and advantageously a lateral space (12) between the disc minutes (lb) and the barrel disc (11).

The lateral spaces (12) are advantageously between 0.1 and 20 millimeters.

It is understood that the respective diameters of the hour disc (la), the minute disc (lb) and advantageously the barrel disc (11) of the seconds, are decreasing.

Let us add that the peripheral edges (3) of the discs (la, lb) are associated with a display indicative means, preferably presented by an annular label (10), while the barrel disc (11) for displaying seconds is associated with a label (10) in the form of a disc, as disclosed in document FR15 58258.

According to embodiments, the indicative display means are presented by labels (10) made of synthetic material, such as polyester, decorated by printing or by screen printing.

An annular label (10) is arranged on the upper surface of a peripheral flange (3) of a lightened display disc (la, lb), while a label (10) in the form of a disc is positioned on the upper surface of the disc-gun display (11) seconds.

According to one embodiment, the labels (10) are fixed with glue.

It is thus the labels (10) which form the joint between the lateral spaces (12) of the discs, leaving only a minimum, or even no visible opening at the level of the upper display surface thus formed, such as illustrated in figure 1.

Additional lateral spaces (13), as illustrated in FIG. 7, are thus arranged between two labels (10), the latter are advantageously between 0.1 and 1 millimeter. Thus, the labels (10) contribute to forming a flat or substantially planar and substantially continuous upper display surface at the X and Y axes (not shown).

According to embodiments, as illustrated in FIG. 7, the labels (10) have a larger dimension than those of a peripheral rim (3) and of the upper surface of the barrel disc (11).

According to one of the preceding embodiments, an annular label (10) extends both beyond the inner and outer periphery of a flange (3), while a label (10) in the form of a disc extends beyond the outer periphery of the barrel disc (11).

According to an additional characteristic, additional lateral spaces (13), as illustrated in FIG. 7, are arranged between on the one hand two annular labels (10) and on the other hand an annular label (10) and a label ( 10) in the form of a disc, the latter are advantageously between 0.1 and 1 millimeter.

SHOCK RESISTANCE TEST

Weight of discs

Lightened Steel Full Aluminum Hours disc 0.94 g 0.68 g Minute disc 0.29 d 0.20 g Canon disc seconds 0.04 g

Test, pendulum sheep

The impact resistance tests are carried out according to the NIHS 9110 standard, using a 5 kg pendulum sheep.

Results and analyzes

Five reference watches, equipped with a display device comprising solid aluminum display discs, were tested by a pendulum pendulum at a relative height of 0.7 meters, none of these parts withstood the test. of the pendulum sheep.

Seventeen watches equipped with a display device comprising discs (1a, 1b) lightened display of minutes and hours in stainless steel and a disc-barrel (11) of seconds in aluminum, according to the embodiment illustrated, have been tested at different heights, as illustrated in the table below.

1: 2 3 4 5 6 AT 12H 0.9 okay okay okay B 12H 0.9 okay okay okay - VS : 12H < 0.9 okay okay okay D 12H 0.9 okay okay okay - E 12H 0.9 okay okay okay - F 12H 0.9 KO okay okay " G 12 0.9 okay okay okay Crooked tooth H 12 0.9 okay okay okay - I 12 0.9 okay okay okay - He 1 „ 12 0.9 okay okay okay K 12 0.9 okay okay okay - The 12H 1 okay okay okay - M 12H 1 okay okay okay - NOT 12H 1 okay okay okay - O 12H 1 okay okay okay - P 12H 1 KO okay okay Non planar minutes disc Q 12H 1 okay okay okay ..

: Shock position, 2 Relative height (in meters), 3: Flatness, 4: De-indexing, 5: Timing, 6: Defect found

OK: no fault found, KO: fault found

Fifteen watches out of seventeen show no abnormality after a shock at 1 and 0.9 meters, i.e. 88% of watches having successfully passed the pendulum sheep test. The P ri watch is more viable, while the G watch has a crooked tooth but the chronometry remains good. Thus, 94% of the watches tested have good chronometry after a first shock.

Thus, watches equipped with a display device (9) according to the invention have excellent resistance after a first impact.

This result is all the more favorable since not only the weights of the lightened display discs (la, lb) of stainless steel are greater than those of aluminum of the reference watches, but also that the relative height of the resistance tests. impact was performed at a height of 0.9 and 1 meter, while none of the reference watches passed the pendulum sheep test at 0.7 meters.

Claims (12)

1. Light display disk (la, lb) of a timepiece comprising in its center an orifice (2) intended to drive out a cannon mounted on a motor shaft of a watch movement, said disk (la, lb ) having a peripheral rim (3) whose inner periphery is connected to at least one junction wall (4) extending towards the center (2) of said disc (la, lb) by a perforated central wall (5), while the rim (3) and the perforated wall (5) are located in two parallel planes forming a clearance (7). 2. Lightened display disc (la, lb) according to claim 1, characterized in that the perforated wall (6) is provided by spokes (6) of reinforcement connecting the center of the disc (la, lb) to the / the junction wall (s) (4). 3. Lightened display disc (la, lb) according to the preceding claim, characterized in that it comprises a number of spokes (6) of reinforcement greater than or equal to six. 4. Lightened display disc (la, lb) according to claim 2 or 3, characterized in that, the flange (3) is connected to junction walls (4) which are extended by the spokes (6) of reinforcement . 5. Lightened display disc (la, lb) according to any one of the preceding claims, characterized in that the peripheral flange (3) comprises perforations (8) regularly distributed. 6. Lightened display disc (1a, 1b) according to the preceding claim, characterized in that the perforations (8) are of triangular shapes, while they are arranged in staggered rows. 7. Lightened display disc (la, lb) according to any one of the preceding claims, characterized in that its constituent material is stainless steel. 8. Display device (9) of a timepiece, characterized in that it comprises at least one lightened display disc (la, lb) according to any one of the preceding claims. 9. Display device (9) according to the preceding claim, characterized in that it comprises at least two lightened display discs (la, lb), said discs (la, lb) being of two different and concentric diameters, while a lightened minutes display disk (lb) is nested in the recess (7) of a lightened hours display disk (la). 10. Display device (9) according to claim 8 or 9, characterized in that a peripheral flange (3) of at least one lightened display disc (la, lb) comprises on its upper surface a label ( 10). 11. Display device (9) according to any one of claims 8 to 10, characterized in that it comprises a disc-barrel (11) for displaying the seconds consisting of a barrel which is in cross section T-shaped, namely consisting of an upper surface, a bore centered on the latter and a lower annular peripheral rib, centered along the axis passing through the bore. 12. Timepiece comprising the display device (9) according to any one of claims 8 to 11.