BE1022205B1 - TRANSMISSION FOR CLOCK AND CLOCK EQUIPPED WITH THIS TRANSMISSION. - Google Patents

Abstract

Transmission for a clock or watch for the transmission of the rotary movement between at least one drive shaft of the clock movement and at least one driven shaft of the display module, characterized in that the transmission comprises a magnetic transmission with at least one pair magnets or magnetic elements (15,17) cooperating by magnetic attraction, without contact or physical mechanical connection, of which at least one magnet (17) or magnetic component is linked to the drive shaft of the watch movement and at least one magnet (15) or cooperating magnetic component is linked to the driven shaft of the display module. Fig. 2

Description

Transmission for clock and clock equipped with this transmission.

The present invention relates to a transmission for use in a watch or clock.

More particularly, it is a transmission that transmits a rotary movement of a watch movement to a display module composed of a driven mechanism and a display dial so that the transmission of the rotary movement is performed without friction. or direct mechanical connection between the drive shaft (s) of the watch movement drive mechanism and the driven shaft or shafts of the display module of the watch or the clock. The display dial consists of indexes and an indication scale.

Among watches or mechanical clocks or watches or clocks with an analogue reading, two broad categories can be distinguished.

A first category, the best known, is that of the watch or the conventional clock provided with a dial with indexes with needles which rotate about an axis under the effect of the drive mechanism of the watch or the clock. 'clock.

A second category, less known, is that of the watch or the clock equipped with disks or rotating rings provided with an inscription. The discs or rings are also directly placed on the drive axes of the watch mechanism or the clock and they replace the indexes. On the rings are affixed the numbers that correspond to the time function of the ring, namely the numbers 1 to 12 for a ring of hours, 1 to 60 for a ring of minutes and a ring of seconds.

A reference or a fixed frame on the clock indicates the reading marks or lines, the numbers being on the outermost fixed ring. A dial module for a watch of this second category has been described in EP 1.003.085 and in EP 2.510.406.

A disadvantage of the watches or clocks of these two categories is that the drive mechanism is fixedly and inseparably connected to the gear used to rotate the indexes in the first category of clocks or to rotate the rotary rings. in the second category.

Therefore, the watch or the clock must be disassembled in the event of a fault or a change of the drive mechanism and does not make it possible to use this same drive mechanism either to drive the indexes in the first category of clocks, to drive the rotary rings in the second category.

A known disadvantage of watches or clocks of the first category is that a parallax error appears during the reading of the time, so that a different time is read according to the viewing angle under which the time is read. . The time read is therefore correct only when the time is read from a viewing direction perpendicular to the dial.

The second category, on the other hand, has the advantage that the rings or discs do not overlap, at least when they have been arranged on the same plane.

An example clock with disks has been described in document CH 676074, but the indexes and the dials are not in the same plane.

An example of a clock with disks and rings has been described in document EP 1.003.085, but has the disadvantage of having a relatively large diameter since a free space is necessary between the indexes and the dials, because the eccentric rotation of the indexes on the dials. Indexes and dials are therefore not on a continuous surface. Dirt and dust can accumulate in the free space, between the indexes and dials, and disrupt the proper functioning of the clock. EP 2,510,406 discloses a dial module provided with several indexes which can rotate about an axis, according to a time scale, on a concentrically arranged dial, where the axes of the indexes can be driven by the movement watchmaker. This dial module consists of a housing with at least two separate indexes, so that the two indexes never overlap and the mobile dial (s) always keep a fixed orientation by relative to the case, where the upper visible part of the indexes and dials was arranged on a single continuous surface.

As dirt and dust can still penetrate between the fixed parts of the surface and the rotating rings, the only continuous surface of the dial should be covered with a protective glass as already known for the clocks of the first category.

The protective glass, however, causes another problem, which is the problem of parallax in lateral view of the continuous surface of such a clock, caused by the free space between the glass and the only continuous surface of the dial, whether it is flat or curve.

The present invention aims to provide a solution for at least one of the aforementioned drawbacks or for other disadvantages. To this end, the invention relates to a clock transmission of the transmission of the rotary movement between at least one drive shaft of the watch movement and at least one driven shaft of the display module, the transmission comprising a magnetic transmission with at least one a pair of magnets or magnetic components cooperating by magnetic attraction, without contact or physical mechanical connection, of which at least one magnet or magnetic component is connected to the drive shaft of the watch movement and at least one magnet or cooperating magnetic component is linked to the driven shaft of the display module.

It is obvious that it is preferable to use several pairs of cooperating magnets in order to better balance the axes to which they are attached.

It is also obvious that a pair of magnets may be composed of a permanent magnet and a magnetic component whose magnetism is induced by the permanent magnet.

An advantage of such a transmission is that the display module can be easily separated from the clockwork drive mechanism without disassembly of the display module itself or the drive mechanism itself, to facilitate repair or maintenance. of the clock and allowing the replacement by another display module also containing a half of a magnetic type transmission. This easy maintenance benefit is even more important when it comes to a complicated watch or clock, as the time required for maintenance is greatly reduced by using pre-assembled modules.

Indeed, it is even conceivable to replace a display module of the first category, being the classic clock equipped with a dial and pointers shaped needles which rotate around an axis under the effect of the watch movement, by a display module of the second category, being the clock equipped with discs or rotary rings provided with an inscription, which rotate under the effect of the watch movement which remains in place.

Another advantage is that the magnets of the magnetic transmission can be separated by a wall for mounting the two mechanisms in separate compartments of the clock housing. The magnetic transmission transmits the rotary movement through this closed wall of the compartment in which the display module is located.

Yet another advantage of the sealed wall of the sealed compartment is that the display module is not exposed to external influences such as moisture, dust, and remains protected.

Preferably the compartment provided with a closed wall comprises the display dial and also a transparent glass protecting the display dial. The space between the transparent glass and the surface of the dial causes the problem of parallax, a problem that can be solved by filling this space with a transparent liquid, so that the only continuous surface appears to be on the surface of the glass so that that any graphic element of the display dial appears to be on the surface of the glass at any angle of observation of the viewer.

For this reason, the display module should be arranged in a compartment, filled with non-drilled liquid to prevent leakage. In this embodiment, the display module must be driven without touching the axis or the drive axes of the watch movement.

This option is especially of interest for display modules of the second category, or the only continuous surface is difficult to read from the viewer's side or grazing angles because of a parallax, but can appear through the liquid as being at the surface at any viewing angle, which facilitates the reading of the display dial. The liquid greatly reduces the refraction of the light that would be passing from the glass to the air and vice versa.

This option is also of interest for divers watches, which must withstand significant external pressures and for this reason are often filled with transparent liquid and thanks to the liquid remain readable from all angles.

In general, the modularity has the advantage of being able to use existing watch movements, by equipping them with rotating magnets. The invention also relates to a watch or a clock which contains a magnetic transmission according to the invention.

A disadvantage is that a conventional drive mechanism with ferromagnetic balance can not work reliably in the presence of a magnetic field.

In order to avoid undesirable magnetic influences on the drive mechanism often of the electromagnetic type, the present invention provides some protective measures. First, the drive mechanism is housed in a conductive material compartment which serves as a Faraday cage to avoid magnetic interference.

In addition, the magnets used in attracting magnet pairs are each composed of two reverse polarity magnets provided with a ferromagnetic body and on both sides of the pairs of magnets. This is to focus the magnetic field through the two pairs of reverse polarity magnets to improve the magnetic attraction between the pairs of magnets, while reducing the dispersion of the magnetic field.

In order to better show the characteristics of the invention, some preferred embodiments of the transmission according to the invention have been described below, by way of example and without any limiting character, with reference to the accompanying drawings, in which: which: Figure 1 shows, schematically and in a plan view, the continuous surface of a clock equipped with rotating discs or rings; Figure 2 shows a section along the line II-II of Figure 1 through the magnetic transmission clock according to the invention; Figure 3 shows a section along the line III-III of Figure 2; Figure 4 shows an enlarged detail of Figure 2 indicated by F4; Figure 5 shows a variant of Figure 2; Figure 6 shows a section along the line VI-VI of Figure 5; Figure 7 shows another variant of Figure 2; Figure 8 is a perspective view of Figure 7; Figure 9 shows a plan view of a display dial of a traditional clock equipped with indexes in the form of needles which rotate about a central axis.

FIG. 1 illustrates the continuous surface 1 of a clock equipped with rotatable disks or rings provided with an inscription, which rotate under the effect of a watch movement, and in this case two indexes, for example a first index 2 which represents the minutes and a second index 3 which represents the hours.

In the example shown, the display dial 4 of the first index 2 is a fixed dial provided with a time scale 6 which is part of the housing 5 of the display module 7 or the clock and which has been realized as an outer ring that is coaxial with the axis 8.

The display dial 9 of the second index 3 is a rotary dial about its axis 10 and has been rotatably housed in a bearing located in a round opening 11 in the disk 12 of the first index 2 and it can rotate around its axis 10 which follows the rotational movement of the disc 12 about the axis 8 synchronously.

The indexes 2 and 3 and the display dial 9 are driven by the mechanism of the clock, the dial 9 of the second index 3 being driven about its axis 10 at a speed of rotation which is equal to that of the first index 2 , but in the opposite direction, so that the dial 9 of the second index 3 still retains, during rotation, the same fixed orientation relative to the housing 5.

The indexes 2 and 3 are driven by the watch movement to indicate, as in a conventional clock, in the known manner, the hours and minutes or other information with respect to a time scale.

In FIG. 2, a section along line II-II of FIG. 1 is shown, showing a housing 5 containing the dial module 13 containing the primary drive shaft 8 and the axis 10 around which the second index rotates in the disk 12 of the first index. The drive of the dial module 13 is done by means of a gear which is in turn driven by the primary axis 8 and / or the secondary drive axes of the clockwork drive mechanism which, for the sake of simplicity , has not been shown in the figures.

Fig. 2 also shows the magnetic transmission 14 according to the invention, which comprises two magnets 15, 16 rotatably mounted on the primary axis 8 of the display module 13 and two other magnets 17, 18 rotatably mounted on the axis 19 of the watch movement 20 in its Faraday cage 21. The two pairs of magnets being in this case separated by a horizontal wall 23 between the display module 13 and its magnets 15, 16 on the one hand and the driving mechanism 20 of the watch movement and its magnets 17, 18 on the other hand.

Figure 3 shows a section along the line III-III of Figure 2, showing an upper view of the two permanent magnets 17, 18 and their circular path 22 around the drive axis 19 of the watch movement.

FIG. 4 shows the detail indicated by F4 in FIG. 2 and shows on an enlarged scale the magnet 16, attached to the primary axis 8 of the display module 13 in magnetic interaction with the magnet 18, attached to the axis 19 of the watch movement. The magnet 16 is composed of two magnets 16a, 16b with a reverse bias, whose magnetic field is reinforced by a ferromagnetic body 24, while the magnet 18 is composed of two magnets 18a, 18b with a reverse bias, whose magnetic field is reinforced by another ferromagnetic body 25.

The magnets 16a and 18a align with their opposite magnetic poles by frictionless magnetic interaction or direct mechanical connection between them, just like the magnets 16b and 18b which have a reverse bias so that a reinforced magnetic field is obtained between the two parts of the magnetic transmission which is capable of driving the primary axis 8 of the display module with the rotation of the drive shaft 19 of the watch movement, and this without direct contact between these two axes.

FIG. 5 shows a variant of FIG. 2 where the magnetic interaction between the magnets of the primary axis 8 of the dial module and the magnets of the drive shaft 19 is in an orientation perpendicular to that of the FIG. 2. The inter-acting magnets are located on concentric paths so that the magnets 15, 16 of the display module 13 rotate at a distance farther from the central axis 8 of the clock than the magnets 17, 18 attached to the drive shaft, while the interacting magnets are separated by a wall 23 vertical instead of horizontal. The primary axis 8 of the dial module operates the same type of watch with disks and rings, with a continuous surface, covered by a protective glass 26.

FIG. 6 shows an upper view of the section indicated by the line VI-VI in FIG. 5, showing in more detail the geometry of the magnets 15, 16 of the display module and the magnets 17, 18 of the axis of FIG. training of the watch movement, each consisting of a pair of reverse polarity magnets 15a, 15b etc. and each pair of magnets is reinforced by a ferromagnetic body 24, 24 'and 25, 25'.

FIG. 7 shows another variant of FIG. 2 where the magnetic interaction between the magnets of the primary axis 8 of the dial module and the magnets of the drive shaft 19 takes place in an inclined orientation with respect to that of Figure 2. The inter-acting magnets are on concentric paths as in Figure 2, while the inter-acting magnets are separated by a wall 23 inclined instead of a horizontal wall. The primary axis 8 of the display module actuates the same type of watch with disks and rings, with a continuous but curved surface, covered by a protective glass curve 27. The wall 23 hermetically closes the compartment of the display module, which is in this case filled with liquid so that the observation under several observation angles always results in an apparent surface without parallax.

Figure 8 shows in perspective a watch 28 corresponding to the section shown in Figure 7 of the type rings and rotating discs which appear at a curved continuous surface.

Fig. 9 shows a plan view of a dial 29 of a traditional clock equipped with indexes in the form of needles 30, 31 which turn about a central axis 32, which can be driven by a mechanism driving a watch movement through a magnetic transmission according to the invention which transmits the rotary movement of the drive shaft to a rotary movement of the indexes in the form of needles 30, 31 on the dial 29.

The operation is simple and proceeds as follows.

A classic clock movement of a watch or clock is provided with one or more magnets that bypass the drive shaft powered by a power source.

Then a display module is mounted above this drive mechanism, also provided with one or more magnets which bypass the primary axis of the display module and which are started under the influence of the magnetic attraction of magnets linked to the drive axis of the watch movement.

The two groups of magnets do not touch each other and form a frictionless transmission or direct physical mechanical connection between the axes concerned.

The dial module may be of a traditional type having a fixed dial and indexes in the form of needles which rotate about the central axis, or may be of an alternative type with discs and rotating rings in a plane continuous flat or curved.

It is even possible to exchange a module of the traditional type for an alternative module or vice versa, while holding the same mechanism for training the watch movement.

It is clear that the display module can be driven by one or more axes of the watch movement by means of one or more magnetic transmissions.

The present invention is in no way limited to the embodiments described by way of example and shown in the figures. On the contrary, a magnetic transmission according to the invention and a watch or clock equipped with such a transmission can be made in all kinds of shapes and dimensions without departing from the scope of the invention.

Claims (11)

claims Transmission for a clock or watch for the transmission of the rotary movement between at least one drive shaft of the watch movement and at least one driven shaft of the display module, characterized in that the transmission comprises a magnetic transmission with at least one a pair of magnets or magnetic elements (15, 17) cooperating by magnetic attraction, without contact or physical mechanical connection, of which at least one magnet (17) or magnetic component is connected to the drive shaft of the watch movement and to the minus a magnet (15) or cooperating magnetic component is connected to the driven shaft of the display module. 2. Transmission (14) according to claim 1, characterized in that the magnets used in each pair of magnets (16, 18) attracting each are composed of two magnets (16a, 16b; 18a, 18b) polarity inverse provided with a ferromagnetic body (24, 25) and this optionally on both sides of the pairs of magnets. 3. Transmission (14) according to claim 1, characterized in that it transmits the rotary movement through a closed wall (23). 4. Transmission (14) according to claim 3, characterized in that the compartment provided with a closed wall (23) comprises the display dial. 5. Transmission (14) according to claim 4, characterized in that the compartment provided with a wall (23) comprises a glass (26) transparent protecting the display dial. 6. Transmission (14) according to claim 5, characterized in that the compartment provided with a wall (23) is filled with a transparent liquid. 7. Transmission (14) according to any one of the preceding claims, characterized in that the compartment provided with a wall (23) can be separated from the watch movement (20) without disassembly of the display module (13) itself or the clock movement (20) itself, and may be replaced by another compartment also containing a half of a magnetic type transmission (14). 8. Transmission (14) according to claim 7, characterized in that the display module is of the first category, being the classic clock provided with a dial and pointers shaped needles that rotate around an axis, or is of the second category, being the clock equipped with discs or rotary rings provided with an inscription, which revolve around one or more axes. 9. Transmission (14) according to claim 1, characterized in that it transmits the rotary movement of one or more primary axes (19) of the watch movement, to one or more primary axes (8) of the module of display. 10. Clock or watch characterized in that it contains a magnetic transmission (14) according to the invention described in the first claim. 11. Clock or watch according to claim 10, characterized in that the drive mechanism is housed in a compartment of material which serves as a Faraday cage (21) to avoid magnetic interference.