Portable object with bracelet and electrical connecting flange penetrating the casing, and method of mounting the flange

The present invention relates to a portable object with a strap provided with electrical connection means through the housing. The portable object includes the features defined in the independent claim 1.

The present invention also relates to a mounting method including the electrical contact strip for a portable object with a strap.

In the present description, the term "electrical connection means" any conductor or set of conductors to ensure an electrical connection between at least one contact terminal of an electronic circuit and at least one conductive track arranged in the wristband. This conductive track can be an antenna for transmitting and receiving signals or enable to electrically connect an electric component contained in the strap and the electronic circuit in the housing.

In a preferred embodiment, the portable object is designed as a portable electronic instrument taking the form of a wristwatch. This wristwatch can include means for receiving or radio frequency type of signal transmission if the conductive track of the wristband defines an antenna. In this case, the electronic circuit of electrical signal processing used to manage the transmission or reception of information signals by the antenna.

Such portable objects have already been described in the prior art with means of electrical connection between an electronic circuit disposed in the housing of the objects and an antenna in the bracelet.

European Patent No. <patcit id="pcit0001" dnum="EP0631341A"><text>0631341</text></patcit> discloses an electronic instrument of the wristwatch type having an antenna housed in the wristband and connected to an electronic circuit for processing the signals received by the antenna. The electronic processing circuit is arranged inside the instrument casing on a printed circuit board. Connecting pads are formed on a peripheral region of the printed circuit board to allow the establishment of an electrical connection between the signal processing electronic circuit and the antenna connection terminals which passes through a sidewall of the housing . In a first embodiment, the fastening screws pass through apertures adapted for the antenna terminals to be screwed directly into the printed circuit board at the connection pads for electrical connection.

In a second embodiment, it is planned to use a leaf spring type connector attached to the printed circuit board for each terminal of the antenna, on which abuts an electrical conductor connected to one of the terminals of the antenna. Each conductor connected to an antenna terminal must cross the side wall in order to press the leaf spring to establish electrical contact. An annular seal is provided around said conductor in the passage through the side wall,

A disadvantage of the electronic instrument shown in European Patent No. <patcit id="pcit0002" dnum="EP0631341A"><text>0631341</text></patcit> is a part of the antenna has to pass through a sidewall of the housing so as to be directly connected on the printed circuit board. Therefore, the seal at the side wall of the housing, even with the annular seal, can not be guaranteed in time and in function of the bracelet handling.

Another disadvantage of the first embodiment with the fixing screws is that subsequent replacement of the antenna in case of problems makes it imperative complete disassembly of the instrument case, before access to the mounting screws, which can make this tedious operation.

Another disadvantage of the second embodiment with the leaf spring is that this blade is typically soldered to the PCB. This must be done carefully to ensure a sufficient mechanical strength with respect to the perpendicular stresses exerted on the blade, once the electrical conductor is placed in abutment against it. It may be noted further that the contact surfaces between the blade and the electrical conductor are not protected, which can lead to stability of the electrical connection problems, in particular because of a possible oxidation of free metal surfaces. Moreover, this solution has a relatively bulky and can therefore be suitable for the realization of a low-volume instrument.

Also exemplary patent <patcit id="pcit0003" dnum="US5168281A"><text>US 5168281</text></patcit> which describes an antenna connection device for an electronic equipment such as a wristwatch. An antenna end housed in a wristband strand is firmly fixed to an electrical conductor. This conductor passes through a sidewall of the housing come to connect a contact blade of a printed circuit board carrying an electronic circuit. An annular seal is provided around the conductor in the passage through the side wall.

As with the previous document, a disadvantage of the solution proposed in the patent <patcit id="pcit0004" dnum="US5168281A"><text>US 5168281</text></patcit> is that the driver of the antenna must pass through a sidewall of the housing so as to be connected against the contact spring on the printed circuit board. Therefore, the seal at the side wall of the housing, even with the annular seal, can not be guaranteed in time and in function of the bracelet handling.

In Patent <patcit id="pcit0005" dnum="US5450091A"><text>US 5450091</text></patcit>There is disclosed a portable object in which the bracelet comprises an antenna which is connected to an electronic circuit in the housing via at least one contact strip through an isolated manner through the side wall of the housing. The contact strip is held sealingly manner through the side wall by insulated joints. However, these insulating joints are not intended to permanently attach the contact strip through the side wall of the portable object, which does not guarantee a good seal at the housing side wall.

The invention therefore primary object to overcome the drawbacks of the prior art by providing a portable object with a strap provided with electrical connection means passing through a sidewall of the sealed housing without being disturbed in particular by various manipulations of the bracelet.

To this end the invention relates to a portable object aforecited which includes the features defined in the independent claim 1.

An advantage of the portable object to bracelet, according to the invention lies in the fact that the intermediate portion of each flange is fastened by a sealing material filled in a cavity formed between first and second portions of the sidewall. The sealing material completely surrounds the flange in the cavity which may be a metal blade, and closes the said flange openings. This sealing material is different from the insulating material used for the side wall. In this way, the sealing of said flange through the side wall is sealed, because the properties of the sealing material does not change over time in the same way that the side wall. It would of course have been imagined molded directly contact strip in the side wall of hard plastic, but sealing problems arise in the long term especially with a flange in the form of metal blade.

Preferably, the sealing material is a polymerizable adhesive or silicone which solidifies at room temperature for a period of time which may be of the order of 24 hours.

The first part of the metal flange inside the housing is advantageously in the S-shaped to form a compression spring. As an upper part of the housing is fixed to a lower portion as a bottom case having the sidewall, a printed circuit board carrying the electronic circuit compresses the first portion of the flange at a contact pad of said plate . Better electrical contact is thus ensured, because the first part of the compressed flange exerts a contact force against the contact pad of the plate.

The second part of the metallic shaped flange plate is disposed above an upper surface of a mounting flange of the bracelet in the rest position, that is to say, before the electrical connection to the conductor track of the bracelet. This second part includes a hole suitable for the passage of a metal screw connection which is screwed into a hole in the rim. The end of the conductive path also includes a hole suitable for the passage of a metal screw. In this way, the end of the conductor track and the second portion of the flange can be fixed on one another against the upper surface of the rim by inserting the screw into each of their hole and screwing the screw into the hole flange.

Note that each hole in the plastic rim can not understand the initial thread, the latter being performed for the first time simply by screwing the connecting screw.

In a preferred embodiment of the present invention, the portable object is a wristwatch having communication means using radio frequency waves. therefore provided to accommodate an antenna in the wristband, which is constituted by the conductive track. This antenna is connected to at least one electronic circuit information signals processing received or transmitted by the antenna.

Thanks to the characteristics of the invention, a good seal is provided to connect the antenna to the electronic processing circuit while having good stability over time.

The invention also aims to provide a method for mounting the electrical connection means of a portable object, characterized in that it comprises the steps of: <ul><li>inserting at least one electrical contact strip through an opening in each wall portion of a cavity formed in a sidewall of the housing, such that a first portion of the flange is positioned within the housing in order to be electrically connected to at least one contact terminal of an electronic circuit, and a second portion of the flange is positioned outside the housing for being electrically connected to at least one conductor track of the bracelet, the dimension each opening being equal to or greater than the cross section of each portion of the flange,</li><li>fill using a specific tool cavity of a sealing material in liquid form, and</li><li>solidifying the sealing material introduced into said cavity to secure the intermediate portion of the flange seal and sealing each opening of the wall portions.</li></ul>

Advantageously, the specific tool to fill the sealing material cavity is guided by guide means provided in each side wall portion to a predetermined distance from the bottom of the cavity, but under each flange passing through said cavity. Filling said cavity in this way, it avoids the creation of air bubbles below the flanges, which could lead not to ensure a good seal when the sealing material has solidified. As the cavity is formed in the side wall from a top edge of said wall in the vertical direction, the bottom of the casing having said side wall can be placed on a suitable mounting bracket to bring the specific tool from above to fill the cavity. Thus, in addition to positioning the tool at a distance from the bottom of the cavity, the sealing material in liquid form may extend over all interior surfaces of the cavity by simple effect of gravity.

The objects, advantages and features of the portable object to the bracelet, and the method for mounting the electrical connection means of the portable object more apparent from the following description of at least one embodiment of the invention in connection with the drawings in which: <ul><li>the <figref idrefs="f0001">1a and 1b</figref> represent a partial sectional view of the portable object and a top view of the bottom of the housing with the side wall and the contact flanges without sealing material of the portable object according to the invention,</li><li>the <figref idrefs="f0002">2a and 2b</figref> represent a three-dimensional view of the bottom with the side wall and the contact strips, and two strands of the strap resting on a mounting flange, and a three-dimensional partial exploded view on the fixing of the ends of the conductor track of the bracelet and flanges contact on the bottom of the rim,</li><li>the <figref idrefs="f0003">Figures 3a and 3b</figref> show an enlarged sectional view of the bottom of the housing at the cavity of two steps of the mounting method of the flange of the portable object according to the invention,</li><li>the <figref idrefs="f0004">4</figref> represents a perspective view of a contact flange used in the portable object according to the invention, and</li><li>the <figref idrefs="f0004">Figures 5a and 5b</figref> represent a side view of the contact flange and a sectional view on AA of <figref idrefs="f0004">5a</figref> Flange for a portable object according to the invention.</li></ul>

In the following description, all elements of the portable object that are well known to those skilled in the art, will not be explained in detail. The embodiment described relates specifically to a portable object by way of non-limiting example in the form of a wristwatch that has the features reception or radio frequency waves broadcast. It should be noted that all elements of the wristwatch described below in the<figref idrefs="f0001 f0002 f0003 f0004">Figures 1 to 5</figref> carry identical reference numerals. Therefore for simplification, it will not repeat the description of each item for all figures.

The <figref idrefs="f0001">1a</figref> shows a schematic sectional view of the wristwatch 1 as an object cell. This wristwatch 1 includes a housing having an upper portion or middle part 3 and a lower portion or bottom 2, a strap provided with two strands 4 and 5 attached to the housing, and at least one button or crown of not shown control. The upper 3 and lower two parts are assembled one on the other housing in the closed position with one end of each strand 4 and 5 by conventional fastening means not shown in<figref idrefs="f0001">1a</figref>. Said ends of the strands 4 and 5 are clamped between the bottom 2 and the middle part 3. An annular seal 17 is placed in an annular groove of the middle part to engage an upper edge of a side wall 15 of the bottom 2 to to seal the closed enclosure. This housing is further closed at the top by a crystal 13 of a conventional type and made for example of plastic or sapphire depending on the desired level range.

In the case of the wristwatch 1 are arranged a battery or accumulator 14 in a bottom of the housing 2 of the housing, a printed circuit board 10 on which is mounted at least one electronic circuit 11 powered by the battery or accumulator, and a liquid crystal display device LCD 12 including time information, text or other functions. The display device 12 is controlled by the electronic circuit 11. slopes electrical conduction not shown are disposed on the printed circuit board for electrically connecting including electrical contact pads 30 disposed at the periphery of said plate for circuit terminals 11 e.

An intermediate spacer 32 is disposed between the LCD device 12 and the printed circuit board 10 to ensure a sufficient height between these two elements and allow the arrangement of the components, such as the electronic circuit 11 shown in the intermediate space thus defined.

According to the invention, the wristwatch also comprises electrical connection means which in particular include electrical contact flanges 8, which are in this embodiment the number of 4 as shown in particular in <figref idrefs="f0001">1b</figref>.

Referring to <figref idrefs="f0001">1a</figref>These flanges 8 are provided for electrically contacting the contact pads 30 on the printed circuit board 10 with the ends of at least one conductive track 6 and 7 disposed in each strand 4 and 5 of the bracelet. Preferably the conductive track 6 and 7 of each strand defines an antenna for transmitting and receiving information in cooperation with the electronic circuit. To do this, the electronic circuit 11, which is placed inside the watch case 1 comprises an information processing unit.

As shown in <figref idrefs="f0001">1b</figref>, The lateral wall 15 comprises two cavities 26 carried from a top edge of said wall in a vertical direction to define a bottom, a first inner portion 27 and a second outer portion 28 of the wall 15. These cavities are arranged in the side wall 15 in diametrically opposed and located at the connection of each end of the strands 4 and 5 of the strap to the housing. Two pairs of contact clips 8 which are positioned parallel one relative to the other, pass through the openings of two wall portions 27 and 28 of the two cavities 26 of the side wall 15 of the bottom 2. The intermediate portion of each pair of flanges 8 is fixed by sealing a sealing material 9 not shown in<figref idrefs="f0001">1b</figref>, Which is introduced into each cavity 26 as hereinafter described with particular reference to <figref idrefs="f0003">Figures 3a and 3b</figref>.

The sealing material is preferably a polymerizable silicone or glue. This sealing material 9 is different from the plastic insulating material used particularly for the side wall 15. In this way, the said sealing flange 8 through the sidewall 15 is sealed because the properties of the sealing material does not alter the over time in the same way as the side wall, which is for example hard plastic.

The electric contact strip 8 used as electrical connection means is shown more clearly in <figref idrefs="f0004">4</figref> which represents a three dimensional view of the flange, as well as <figref idrefs="f0004">Figures 5a and 5b</figref>. This contact strip 8 is made from a strip of metal material good conductor of electricity, such as a copper alloy composed. The thickness of this strip may be of the order of 0.1 mm.

With reference to <figref idrefs="f0004">Figures 4 and 5a</figref>The flange comprises a first portion 8a S-shaped, a second portion 8b and the intermediate portion 8c which is intended to be fixed through the side wall of the bottom of the casing by the sealing material.

The first part 8a S-shape of the flange 8 constitutes a compression spring. In the closed position of the housing, the printed circuit board pressed with a determined force F each first part of the flanges 8 at the contact pads of the printed circuit board. This allows to establish good electrical contact between the flange and the corresponding contact pad. The first part 8a of the flange 8 thus compressed is shown in broken lines in<figref idrefs="f0004">5a</figref>.

As shown in <figref idrefs="f0001">1a</figref>, The printed circuit board 10 rests on a spacer 19 separating it from the stack 14. This can also allow to avoid unnecessary damage to the first portion of each flange 8 at the time of closing the housing.

With reference to <figref idrefs="f0004">Figures 4 and 5a</figref>The intermediate portion 8c and the second part 8b of the flange have the general shape of blade. The second part 8b of the flange is pierced with a hole 18 so as to be fixed to one end of a conductive track as explained below. In addition, the end of the second portion 8b of the flange is tapered so as to facilitate the mounting of the flange through the apertures of the wall portions welcoming before fixing by the sealing material.

A boss 29 can be performed in particular by stamping or die forming in the intermediate portion 8c of the flange to be usable for positioning said flange in apertures in each side wall portion. Each opening is thus provided of sufficient size in said wall portions to facilitate insertion of the second part. The height of each opening may be for example 0.2 mm, while the thickness of the second portion is 0.1 mm. Against by the height of the protrusion may be substantially equal to the height of each opening which allows to position the intermediate portion of the flange prior to the introduction of the sealing material in the cavity of the side wall. The width of each opening of the wall portions receiving a flange may be substantially equal to or slightly greater than the width of the flange.

As shown in <figref idrefs="f0001">1a</figref>, <figref idrefs="f0002">2a and 2b</figref>, The second outer portion of each flange 8 is thus connected to a respective end of a conductive track 6 and 7 defining a particular antenna of each strand 4 and 5 of the bracelet. This electrical connection is made by means of headed stems, such as connection screw 24 screwed into respective holes 23 formed in a plastic rim 20 of the bottom 2 in extension of the side wall 15. Each hole can be self-tapped by the connecting screw or may initially include a thread.

Each threaded part of the connecting screw 24 passes through a suitable hole 18 of the second portion of the flange 8 and a hole 42 adapted to the end of the conductive track 6 and 7 corresponding to connect. As the screw head is of larger diameter than the holes 18 and 42, the second portion of the flange and the end of the conductive track can come into direct contact with the upper surface of the insulating flange 20 completely tightening each screw connection 24 into the threaded holes 23.

The end of each strand 4 and 5 of the bracelet is attached to the casing between the flange 20 of the bottom extension of the side wall 15 and the middle part 3 by the fastening means which hold the upper portion 3 of the lower part 2 of the housing .

As can be seen the <figref idrefs="f0001">1b</figref> and <figref idrefs="f0002">2b</figref>Two tubular portions 22 are formed on each flange 20 for receiving the corresponding end of the strand to be fixed to the housing. Each end of the strands comprises two openings 41 having complementary shapes to be fitted on the tubular portions 22. Mounting screws 40, shown in<figref idrefs="f0002">2a</figref>, Pass through each hole 21 of the tubular portions 22 and each aperture 41 of the bracelet strands in order to be screwed into threaded holes in the upper part not shown. Thus, the bracelet is attached to the housing when the latter is closed.

It should be noted that as regards a possible replacement of the bracelet, or at least the strands 4 and 5, simply loosen the screws of the housing 40, to remove at least 41 holes of strands, separate the bottom 2 of the middle part 3 of the housing and unscrew the screw connection 24.

Referring to <figref idrefs="f0002">2b</figref> showing a partial exploded view of the mounting of the end of the wristband strand to the watch case, each end of the strip conductor 7 is positioned on the second portion of the corresponding flange 8 so that the holes 18 and 42 are arranged substantially coaxially. Once the end of the strand is positioned, the connecting screw 24 may be inserted into the holes 18 and 42 in order to be screwed into the threaded holes of the flange 20. As the second portion of the flange 8 remote from the upper surface of flange 20, this second portion can flex elastically when the connecting screw is screwed until it comes into contact with the upper surface of the flange. Thus, good electrical connection is established between each flange and the corresponding end of the conductor track.

With reference to <figref idrefs="f0003">Figures 3a and 3b</figref>The steps of the method for mounting the electrical connection means of the portable object, such that the electrical contact clips are explained in more detail.

The bottom 2 of the housing is first placed and held on a work surface. Each electric contact strip 8 is introduced from the second part, whose end is narrowed, through each opening 31 formed in the portions 27 and 28 of the side wall 15. Thanks to this narrowing of the second part and the fact that the thickness of the blade is almost twice as low as the height of the opening 31, the introduction of this flange is facilitated. Said flange 8 is inserted through the openings 31 from inside the housing until the hole 18 of the second part is positioned substantially coaxially with the threaded hole 23 formed in the flange 20. The intermediate portion of the flange is well positioned in the openings 31 of the portions 27 and 28 with the boss 29 whose height is substantially equal to the height of each opening 31.

As two flanges must be mounted through each cavity 26 of the side wall, the operations indicated above are performed either simultaneously for all the flanges, either separately for each flange 8.

Once the two flanges 8 are positioned through the openings 31 of cavities 26, a specific tool 50 such as a syringe, is fed into the cavity 26 to a certain distance from the bottom of the cavity in order to introducing the sealing material 9 in liquid form, as the polymerizable silicone or glue. The specific tool is guided in its descent by guiding means 16, also visible in the<figref idrefs="f0001">1b</figref>, <figref idrefs="f0002">2a and 2b</figref>. These guiding means 16 made partly in each portion 27 and 28 of the side wall are located between the two flanges to be fixed. These guiding means have a substantially complementary shape to the conical part of the specific tool. This allows to stop the tool during its descent into the cavity up to a determined distance from the bottom of the cavity underneath each intermediate portion Positioned flanges. The location of the specific tool in the cavity is shown by broken lines in<figref idrefs="f0003">3a</figref>.

Once the specific tool 50 is in position in the cavity 26 indicated by broken lines in <figref idrefs="f0003">3a</figref>A specific quantity of liquid polymerizable adhesive is introduced into the cavity from the lower end of the tool. The liquid adhesive 9 spreads in said cavity 26 in each opening 31 also plugging portions 27 and 28 without overflowing and coating the intermediate portion of the flanges 8. By introducing the glue from the bottom of the cavity, this avoids creating bubbles air in the cavity that could affect the seal flanges fixed through the side wall. In addition to the effect of gravity, the glue spreads uniformly in said cavity to fill it completely.

Once the liquid adhesive was introduced until the upper edge of the cavity 26, the tool 50 is removed progressively from the cavity. The tool can enter the adhesive while leaving the cavity so that the level of the introduced adhesive reaches the upper edge of the cavity 26. From this moment, a certain period of time must be counted so that the adhesive solidifies as shown in<figref idrefs="f0003">3b</figref>. This period of time may be of the order of 24 h at room temperature. As the adhesive is elastic with relatively good adhesion to the inner surfaces of the cavity 26, this allows to seal said sealing flange in the cavity 26 of the side wall 15 which is one of the goals sought by the invention.

One can also notice on <figref idrefs="f0003">Figures 3a and 3b</figref> that the outer portion 28 of the side wall comprises a flare 25 as a result of the opening 31 for passage of the flange. This widening 25 is provided to allow the second portion of the flange, which is remote from the upper surface of flange 20 in the rest position, to be able to bend without permanent deformation. In this way, the second flange portion can be fixed with one end of the conductor track of the bracelet by means of the connection screw to come into contact with the upper surface of flange 20 as explained above.

Once the contact clips 8 are secured through the side wall, the mounting of all components inside the bracelet can be undertaken including the printed circuit board which compresses the first portion of each flange at the contact pads upon closure of the housing.

It can be provided that instead of the boss of the intermediate portion of each flange, it is practiced two blisters for each housed in an opening of each side wall portion. It may only be provided by a flange cavity to connect each end of a single conductive track accommodated in the strap.