CH714413B1 - Timepiece comprising an electric motor fixed to a fastening plate. - Google Patents

Abstract

The invention relates to a timepiece comprising a middle part closed by a crystal, and the following elements positioned in the middle part: a dial (CD), a rigid hooking plate (PA) extending under the dial (CD) , a module comprising an electric motor, said motor module (MD), a printed circuit of which at least a first portion (P1) is interposed between the attachment plate (PA) and the motor module (MD), means of assembly (VS) of the motor module (MD) to the attachment plate (PA) through the first portion (P1) of the printed circuit.

Description

Field of the invention

The invention relates to the field of quartz watches and analog display. This type of watch has as a regulator a quartz oscillator vibrating under the effect of the electric energy supplied by a battery and which, associated with an electronic circuit, drives a step-by-step motor rotating display hands. .

Background of the invention

We know the patent application EP 1 760 557 A1, describing a quartz watch and analog display. The timepiece comprises a case including hands, a dial made of semiconductor material and extending below the hands, a printed circuit board arranged under the dial, and a drive device mounted on the underside of the dial. printed circuit board. The drive device comprises an electric clock motor and transmission means making it possible to obtain the gear ratio required for driving each hand. The printed circuit board is rigid and rests on the edges of the case. In addition, a printed circuit element is etched in the dial, this printed circuit element comprising connection pads electrically connected to conductive tracks of the printed circuit board.

This device has several drawbacks. A first drawback is that the printed circuit board must be rigid, yet flexible printed circuits have many advantages over rigid printed circuits: saving space and weight, ease of integration, better resistance to difficult conditions and vibrations. . A second drawback is that the dial is electrically connected to the printed circuit board, which complicates the manufacture and assembly of the timepiece. A third drawback is that the number of electronic components that can be mounted on the printed circuit board (for example antennas, sensors, integrated circuits, etc.) is low: they can only be mounted on the bottom surface of the printed circuit board.

Summary of the invention

[0004] The aim of the present invention is to overcome at least one of the drawbacks mentioned above.

To this end, the invention relates to a timepiece comprising a middle part closed by a crystal, and the following elements positioned in the middle part: a dial, a rigid attachment plate extending under the dial, a module comprising an electric motor, called a motor module, a printed circuit of which at least a first portion is interposed between the attachment plate and the motor module, means for assembling the motor module to the attachment plate through the first portion of the printed circuit.

[0006] In one embodiment, the dial is intended to be positioned under a glass of the timepiece so as to be visible to a user. In another embodiment, this dial is covered with at least one other layer, for example an assembly comprising a solar cell, the assembly being held on the dial by means of a double-sided adhesive. The dial would thus not be, or only partially, visible through the glass. The upper layer, the one visible through the ice, could then carry the indexes.

[0007] According to the invention, the motor module is not directly attached to the dial as in the aforementioned prior art document, the dial therefore does not need to be formed from a type of material particular, to have a particular structure or to be connected to electrical connection pads.

[0008] According to a non-limiting embodiment, the printed circuit comprises a second portion disposed against the motor module, such that the motor module is interposed between the first portion and the second portion, the printed circuit further comprising a lateral tab connecting the first portion and the second portion.

[0009] Thus, it is possible to mount a large number of electronic components on the printed circuit board, because components can be attached to the first portion and to the second portion, on one or the other of their faces. depending on what is technically possible.

[0010] According to a non-limiting embodiment, the printed circuit is flexible. Alternatively, the printed circuit is rigid over the majority of its surface, and comprises at least one flexible part (forming the tongue) making it possible to fold at least one of its parts onto the lower part of the motor module to form the second part.

The use of a flexible printed circuit is possible because the motor module is supported by means of the rigid attachment plate. It is noted that flexible printed circuits have many advantages, already mentioned, compared to their rigid equivalents.

[0012] According to one embodiment, the timepiece comprises a spacer, a part of which is disposed laterally on either side of the motor module and sandwiched between the first portion and the second portion of the printed circuit.

Thus, the surfaces of the first portion and of the second printed circuit portion can be larger than the upper surface and the lower surface of the motor module, the portions of the printed circuit which are not in contact with the motor module then resting on the spacer.

Advantageously, for reasons of cost savings, the spacer is made of plastic. Advantageously, the spacer is formed in one piece.

[0015] According to one embodiment, the timepiece comprises an electric battery installed in a housing of another part of the plastic spacer.

Brief description of the drawings

Other features and advantages will emerge clearly from the description which is given below, by way of indication and in no way limiting, with reference to the accompanying drawings, in which Figures 1 and 2 show various views of a part of a timepiece according to the invention.

Detailed description of the preferred embodiments

Referring to Figures 1 and 2, a timepiece according to the invention comprises, among others: - A CD dial, an upper surface of which has a peripheral zone having indexes (not shown). The CD dial is intended to be positioned under a glass of the timepiece so as to be visible to a user. In another embodiment, this CD dial could be covered with at least one other layer, for example an assembly comprising a solar cell or a digital display, the assembly being able to be maintained on the dial by means of a double-sided adhesive. The CD dial would thus not be, or only partially, visible through the glass. The upper layer (that is to say that on the side of the watch crystal; the lower term referring on the contrary to the case back side of the watch) could then carry the indexes. - A rigid PA hanging plate, located under the CD dial. In the non-limiting embodiment shown, the dimensions of the hooking plate PA are substantially identical to the dimensions of the dial CD, so that these two layers are almost perfectly superimposed. The attachment plate is for example metallic. - A module comprising an electric motor, called MD motor module. Said motor is intended, among other things, to rotate the display hands (not shown) of the timepiece around an axis AX. - A printed circuit board CI (in English "printed circuit board", abbreviated by PCB). In the non-limiting embodiment described, the printed circuit CI is at least partly flexible and comprises three portions: A first portion P1 interposed between the attachment plate PA and the motor module MD. An upper surface of the motor module MD is disposed against the first portion P1, and an upper surface of the first portion P1 is disposed against the attachment plate PA. In addition, the motor module MD, the first portion P1 of the printed circuit and the attachment plate PA are fixedly assembled. • A second portion P2 disposed against the motor module MD, such that the motor module MD is interposed between and held against the first portion P1 and the second portion P2. • A lateral tab LG connecting the first portion P1 and the second portion P2. - A plurality of electronic components CE fixed on the lower face of the first portion P1 of printed circuit CI, and on the upper face and the lower face of the second portion P2 of printed circuit CI. CE components are for example antennas, sensors, integrated circuits, etc. It should be noted that using a folded printed circuit CI makes it possible to have a large surface available for placing the electronic components CE. - A spacer EP, in one-piece plastic in the non-limiting embodiment described, a first part EP1 of which is located laterally on either side of the engine module MD, and sandwiched between the first portion P1 and the second portion P2 of the printed circuit board CI. A second part EP2 of the spacer EP comprises a housing for accommodating an electric battery or an accumulator. - An electronic battery PE (or an accumulator) housed in the housing of the second part EP2 of the spacer EP, and making it possible to supply the electric motor MD and the plurality of electronic components CE.

Note that the axis AX crosses orthogonally the first portion P1 of printed circuit CI, the hook plate PA, as well as the dial CD. The display hands of the timepiece are intended to rotate above the CD dial and around the AX axis.

Furthermore, as mentioned above, the motor module MD, the first portion P1 of the printed circuit CI and the attachment plate PA are assembled via fixing means, which for example comprise screws VS.

Of course, the present invention is not limited to the example illustrated but is susceptible to various variants and modifications which will appear to those skilled in the art within the framework of the appended claims.

Claims (6)

1. Timepiece comprising a middle part closed by a crystal, and the following elements positioned in the middle part: - a dial (CD), - a rigid attachment plate (PA) extending under the dial (CD), - a module comprising an electric motor, called the motor module (MD), - a printed circuit (CI) of which at least a first portion (P1) is interposed between the attachment plate (PA) and the motor module (MD), - Assembly means (VS) of the motor module (MD) to the attachment plate (PA) through the first portion (P1) of the printed circuit (Cl). 2. Timepiece according to the preceding claim, the printed circuit (C1) comprising a second portion (P2) disposed against the motor module (MD), such that the motor module (MD) is interposed between the first portion (P1) and the second portion (P2), the printed circuit (C1) further comprising a lateral tab (LG) connecting the first portion (P1) and the second portion (P2). 3. Timepiece according to one of the preceding claims, the printed circuit (C1) being flexible. 4. Timepiece according to one of claims 2 and 3, comprising a spacer (EP) of which a first part (EP1) is disposed laterally on either side of the motor module (MD) and sandwiched between the first portion (P1) and the second portion (P2) of the printed circuit (Cl). 5. Timepiece according to claim 4, the spacer (EP) being made of plastic. 6. Timepiece according to claim 4 or 5, comprising an electric battery (PE) installed in a housing of a second part (EP2) of the spacer (EP).