FR3046704A1 - FLEXIBLE HOUSING FOR SENSOR - Google Patents

Abstract

An electronic component (1) comprising a plurality of rigid housings (11, 12, 13) each incorporating a subcomponent; said rigid boxes being connected, in pairs, by a flexible connection (10) integrating an electrical connection (20) between the sub-components integrated in said boxes, said flexible connection allowing at least one rotation of a box relative to the another along axis parallel to said boxes and located therebetween; characterized in that: - the electrical connection (20) is located at the neutral fiber D-D of the flexible link; and the deformation of said flexible link is limited in the directions of rotation by at least one mechanical stop constituted by the shape of said boxes.

Description

FLEXIBLE HOUSING FOR SENSOR

The present invention relates to a deformable electronic component that can be subjected to significant mechanical stresses. The invention relates in particular to a data sensor intended to be worn or placed on an object, for measuring and monitoring the sports performance of a person in real time, said sensor undergoing deformations.

A sensor typically consists of several electronic components for collecting, recording and / or analyzing data relating to a person practicing a given activity. These components are generally mounted on one or more supports, and connected together by means of electrical connections that can be rigid or flexible. To avoid damaging these connections, it is known devices comprising stiffening means, for example metal reinforcements attached nearby. A bonding of overmoulded elements, in particular, makes it possible to mechanically protect the electrical connections from stresses and possible permanent deformations.

However, these stiffening means are often insufficient to avoid the occurrence of damaging stresses during certain uses of the device, particularly when applying forces and moments of force, for example due to violent shocks. Although the addition of rigid elements makes it possible to protect the deformable zones of a sensor, the electronic sub-components of such a sensor may suffer permanent damage when the device is subjected to tensile, compressive, significant shear and / or torsion and / or regular near the areas where these rigid elements are located.

This poses the problem of protecting the electronics ensuring the operation of such sensors subjected to such constraints, while allowing these same sensors to adapt to different surfaces and geometries. The invention thus aims to propose a protection system in deformation, protecting the electrical connections of a sensor with the aid of a mechanical stop constituted by the shape of the elements constituting said sensor, in order to increase its safety, and in particular the resistance to shocks, pressures or any external influence that may damage said sensor.

For this purpose, the invention relates to an electronic component comprising: a plurality of rigid boxes each integrating a subcomponent; said rigid housings being connected, in pairs, by a flexible connection incorporating an electrical connection between the subcomponents integrated in said housings, said flexible connection allowing at least one rotation of a housing relative to the other along a parallel axis to said housings and located therebetween; characterized in that - the electrical connection is located at the neutral fiber of the flexible link; and - the deformation of said flexible connection is limited in the directions of rotation by at least one mechanical stop constituted by the shape of said housings. According to various additional features that may be taken together or separately: said housings are symmetrical with respect to a plane passing through them and in that said flexible connections are located in this plane of symmetry, the materials used to form said rigid housings are thermoplastic polymer materials. said subcomponent is a power source, a rigid printed circuit or a flexible printed circuit. said flexible connection is made of a material consisting of a thermoplastic elastomer. said electrical connection further comprises a flexible printed circuit, strands of electrical conductors or individual electrical conductors. said electronic component further comprises a plurality of accelerometer type sensors, gyrometer, frequency meter, thermometer or pressure sensor. Other features, details and advantages of the invention will emerge on reading the description made with reference to the accompanying drawings given by way of example and which represent, respectively: FIG. 1a, a plan view of an electronic component according to the invention; - Figure 1b, a sectional view along B-B shown in Figure la according to the invention; - Figure 2a, an elevational view of an electronic component according to the invention; - Figure 2b, a sectional view along D-D shown in Figure 2a according to the invention. Figures 3a, 3b and 3c, respectively, several elevational views of three examples of use of the invention according to the same embodiment.

Naturally, to meet specific needs, a person skilled in the art may apply modifications in the following description. Although it refers to various embodiments, the present invention is not limited to these specific embodiments, and any modifications specific to the scope of the present invention may be considered obvious to a person skilled in the art. the art of the corresponding technique.

Conventionally, data sensors used in the sports field include a wide variety of electronic components. These electronic components are configured to measure and record the metric performance of a moving object. The measured and recorded performances include, among others, the position, the speed, the forces or the pressures acting on this object. These data are typically measured using accelerometers, gyrometers, heart rate monitors, pressure sensors or thermometers integrated in these sensors. Said data is then recorded using an electronic device, comprising for example a memory and a microprocessor.

For optimal operation, the collection of data relating to these different types of activities will be all the more precise as the electronic sensor or sensors will be close to the moving object. In addition, it is preferable that the electronic components constituting them are flexible so that they fit and adhere to the shape of the wrist or the utensil used. It is therefore advantageous to be able to produce electronic components that can be mounted and / or joined to an object, or to any support of this object.

An electronic component according to the invention is intended to be worn by a person, or to be hooked to a garment or a sports implement used by this person. For example, the recognition of a golfer's wrist movements and the characterization of these movements from measurable data such as its position, speed or acceleration, is performed with one or more electronic components, consisting of a sensor placed as close as possible to the golfer's wrist. This type of sensor can also be used for other sports activities, such as tennis or skiing.

Such a sensor typically integrates several electrical components, said components being mounted on, and preferably in a rigid support to limit the mechanical stresses experienced by these same components. In order to function, said components are interconnected by electrical connections that are also subjected to mechanical stresses and that can be damaged permanently. The object of the invention thus relates to an electronic component, whose electrical connections are mechanically protected by means of a natural stop to increase the security of said component vis-à-vis any deformation.

Among the advantages of an electronic component according to the invention, mention may be made of the safety of the electrical connections while preserving the portability, the lightness and the flexibility of the materials constituting the device. These features facilitate, among other things, the folding of the device in a restricted volume and in predefined directions, while allowing the sensor to adapt to different geometries. With the structure as described below, said device can be manufactured in an automated manner and at a very low cost.

Referring to Figure la, one can see a plan view of an electronic component 1 according to the invention. Figure 1b illustrates a sectional view along the axis B-B shown in Figure la. As shown, the device 1 is substantially pentagonal in shape and has curved edges. It will be understood that the invention may relate to any other type of geometry that may designate an electronic component subjected to mechanical stresses.

The body of component 1 is typically made of plastic materials, or any other stable material suitable for carrying out the invention. The materials used may for example be thermoplastic elastomers, which have the property of being electrical insulators and of having a high elasticity. Such materials melt and harden, reversibly, under the action of heat. This characteristic also gives the device the possibility of easier production by molding, and makes the materials more easily recyclable. In addition, the compressible and extensible nature of these materials also allows them to provide a seal to the device. The assembly is obtained by any known means, such as gluing or welding.

As shown in FIG. 1a, the component 1 typically comprises a plurality of elements connected to each other. In the context of the present invention, the construction described above can be the subject of multiple variants. The housings protecting the subcomponents of the device may be more or less numerous. According to the invention, the component 1 comprises a plurality of rigid housings 11, 12, 13 arranged to contain and protect sub-components of the device. As shown in Figure lb, said housings are closed on all their edges. The contours of these housings are covered with rigid elements 14 made of, for example, thermoplastic polymers. Advantageously, these rigid elements are sealed to the housings.

These rigid housings, and / or subcomponents contained by these housings, are connected to each other by one or more flexible links 10. Each of these links provides a mechanical coupling between two of these housings, allowing the flexion of the entire device. Likewise, these links ensure the mobility of the housings relative to each other, for example under the effect of traction, compression, shearing and / or torsion applied to any one boxes, or more of them. These flexible links are also intended to contain electrical connections between the various subcomponents. Those skilled in the art will understand that a flexible connection according to the invention is a connection allowing flexibility in bending and / or torsion of the housings around one or more pivot axes. Said flexible connection is therefore different from the case of a rigid connection between two housings, as for example the case of a hinge, which allows only the pivoting of a housing relative to the other around the pivot axis of the hinge, or parallel to this axis. In particular, the transmission of stresses during the effects of traction, compression, shear and / or torsion to the electrical connections contained in the flexible connections is clearly different from what can happen in the case of rigid hinges.

In addition, these rigid housings incorporate one or more subcomponents constituting the electronics of component 1. The delicate elements of the device, are thus mechanically protected from external stresses by said rigid housings.

FIG. 2a and FIG. 2b respectively show an elevational view and a sectional view along the D-D axis of an electronic component according to the invention. As shown, the electronic component 1 comprises at least two housings, in this case in this example three rigid housings 11, 12, 13. These rigid housings may contain electronic subcomponents 21, 22 and 23, possibly different. A plurality of electrical connections 20 are made between these subcomponents. These electrical connections are, for example, made of an electric wire and / or a flexible printed circuit. Each electrical connection emerges from a sub-component of a given rigid housing to make electrical contact with a subcomponent in a nearby rigid housing. In addition, each of the electrical connections 20 connecting the subcomponents integrated to two rigid housings are embedded in a compressible and extensible material as described above, and are thus included in the flexible links 10 separating said housings.

As previously described, each of the rigid housings provides a cavity for receiving a subcomponent. According to the invention, the housings 11 and 13 located at the ends of the device each comprise a power supply source 21. This power supply source is for example an electric battery or a battery. The central housing 12 comprises an electrical subcomponent that can be, in particular, a rigid or flexible printed circuit, and for producing the electronics of the device. Said printed circuit, and the corresponding electronics, make it possible, for example, to produce measuring means, recording means, and / or transmission means for the operation of the electronic component 1.

It will be noted that the invention may be supplemented by other external or internal subcomponents, for example one or more sensors of the accelerometer, gyrometer or pressure type. The device may also comprise wired or wireless communication means. The invention may comprise, in particular, an NFC antenna (for Near Field Communication, in English) "Near Field Communication", or a module BLE (for Bluetooth Low Energy, in English). These communication means may comprise a wired connection, for example of the Ethernet or CPL type, a wireless connection, for example of the WiFi or Bluetooth type, or any other type of connection which may vary according to the preferred hardware for the implementation of the invention. . On the outer surface, the component 1 can also integrate external subcomponents, for example an array of LEDs, copper tracks, or a display cell. Although these external subcomponents are not protected from stresses applied to the component 1, additional stiffening means can be added to the lower, upper and / or lateral parts of the device, for example metal or polymer soles, to protect the said components. external subcomponents.

FIG. 3a, FIG. 3b and FIG. 3c show an elevational view of three different examples of use of the invention according to the embodiments as previously described. In these figures, the line referenced o represents the horizontal, the component being initially laid horizontally, or the axis of the other housings, parallel to said housings and located therebetween. According to the invention, the flexible links 10 ensure the mobility of two housings with respect to each other, for example under the effect of an angle of rotation w resulting from a twisting or bending of the component 1.

In material resistance, the neutral fiber of a flexural beam is defined in the following way: the part closest to the center of curvature (concave) undergoes compression, the furthest part (convex) undergoes traction . The fibers that make up the concave part undergo a shortening, the others an elongation. The surface located at the center of the beam and formed by the fibers which undergo neither shortening nor elongation but only bending is called the neutral fiber web.

By analogy, we define the neutral fiber of the flexible links of the device as the central part undergoing the least stress during the folding of the flexible link.

According to the invention, the electrical connections 20 integrated to the flexible links 10 and made between the subcomponents of two separate rigid housings are arranged along the neutral fiber of these links. In case of bending of the device, said connections are thus arranged along a curve corresponding to the minimum stress zone of said links. The application of a stress to the whole of the component 1, for example the application of a torsion or a bending, typically imposes a rotation of a housing with respect to another housing along an axis parallel to these two boxes and located between them. Under the effect of said rotation, the curvature of the characteristic fibers of the flexible links is modified. In terms of mechanical deformations, the concave part of this curvature, that is to say the part closest to the center of curvature, undergoes compression under the effect of the deformation, whereas the convex part is that is to say the part closest to the center of curvature, undergoes a pull under the effect of this same deformation. In terms of mechanical deformations, this compression and this traction respectively correspond to an approximation and a distance of the transverse sections, and thus to a bringing together and a removal of the rigid housings constituting the electronic component 1.

In FIG. 3a, a rotation of an angle w makes it possible to modify the position of the housing 13 with respect to the housing 12. In particular, this rotation can be carried out around an axis situated perpendicular to the plane of the figure and passing through the the middle of one of the flexible links 10. Said rotation is mechanically limited: a maximum angle of rotation is reached when at least one edge of one of said two housings touches an edge of the other of said housings at a stop point bl. This mechanical limitation of the angle of rotation of the housings and thus of the torsion imposed on the flexible connection between these housings, called the abutment, thus protects the flexible zones and in particular the electrical connections of the flexible links of the component 1 using a stop mechanism when any of the housings 11, 12, 13 is rotated relative to another housing, for example under the effect of torsion or bending. This stop prevents a breakage of the device and materials constituting it in case of a stress applied too important.

In addition, the flexible connection around the electrical connection 32 between 12 and 13 being disposed along the neutral fiber, the mechanical stresses applied to said connection minimize the deformations thereof. The combination of a mechanical stopper bl and the arrangement of the electrical connection 32 along the neutral fiber component 1 thus allows to limit the amplitude of said constraints.

Similarly, Figure 3b shows an example of use of the invention when two separate rotations are applied to two different housings. As shown, a first rotation of an angle w1 makes it possible to modify the position of a first rigid housing 11 relative to the housing 12 along the axis o, and a second rotation of an angle w2 makes it possible to modify the position of a third rigid housing 13 relative to the housing 12 along the same axis o. Each of said rotations is limited by a different stop point, bl and b2, these two mechanical stops to protect the electrical connection 31 between 11 and 12 and the electrical connection 32 between 12 and 13 of a global deformation of the electronic component 1.

FIG. 3c illustrates a third example of use of the invention when two different rotations of angles w1 and w2 are applied to the device 1, but along two different parallel axes ol and o2. In particular, a first rotation of an angle w1 makes it possible to modify the position of a first rigid housing 11 below the housing 12 with respect to an axis ol, and a second rotation of an angle w2 makes it possible to modify the position a third rigid housing 13 above the housing 12 with respect to an axis o2. The stop points b1 and b2 are in this case located on either side of the horizontal plane passing through the three housings 11, 12, 13, for the case of various deformations applied to component 1. These deformations can result from various constraints of traction, compression, shear and / or torsion applied to one or more of said housings.

According to a preferred embodiment, the flexible links are located at the horizontal plane through the housings, the latter having a symmetry with respect to this plane. This configuration is that illustrated in Figures 3a to 3c. Thus, the mechanical stops being symmetrical, the rotation angles of the housings between them are limited by the same limit angle thus unifying the maximum stresses imposed on the electrical connections.

These examples of use illustrate how a given constraint applied to the flexible links is always limited in the directions of rotation by at least one mechanical stop constituted by the shape of the flexible device, in particular the edges of the rigid housings constituting said device. Most or all electronic components are thus included in a flexible system, but nevertheless protected from damage that may be caused by external influences during any use of the device.

Claims (7)

An electronic component comprising: a plurality of rigid housings (11, 12, 13) each incorporating a subcomponent (21, 22, 23); said rigid housings being connected, in pairs, by a flexible connection (10) integrating an electrical connection (20) between the subcomponents integrated in said housings, said flexible connection allowing at least one rotation of a housing with respect to the another along an axis parallel to said housings and located therebetween; characterized in that - the electrical connection is located at the neutral fiber (D-D) of the flexible link; and - the deformation of said flexible connection is limited in the directions of rotation by at least one mechanical stop constituted by the shape of said housings. 2. Component according to claim 1, characterized in that said housings are symmetrical with respect to a plane passing through them and in that said flexible connections are located in this plane of symmetry. The component of claim 1, wherein the materials used to form said rigid housings are thermoplastic polymeric materials. The component of claim 1, wherein said subcomponent is a power source, a rigid printed circuit, or a flexible printed circuit. 5. Component according to claim 1, wherein said flexible connection is made of a material consisting of a thermoplastic elastomer. The component of claim 1, wherein said electrical connection further comprises a flexible printed circuit, strands of electrical conductors or individual electrical conductors. The component of claim 1, further comprising a plurality of accelerometer, gyrometer, frequency meter, thermometer or pressure sensor type sensors.