Shock-resistant control module

Description

Technical field of the invention

[0001] The invention falls within the field of electronic devices, and in particular components enabling the control of functions of an electronic device.

[0002] More specifically, the invention relates to a control module for an electronic device adapted to withstand shocks.

[0003] Advantageously, the present invention is particularly suited to portable electronic devices, for example electronic watches. Technological background

[0004] The control mechanisms of electronic devices are generally made up of switches adapted to allow or prevent the passage of a current, enabling, for example, the transmission of a command for the execution of a function.

[0005] In particular, in order to allow or prevent the passage of a current, switches are designed to occupy a rest position and a connection position, in at least one of which they are driven by the action of a user.

[0006] We are particularly familiar with switches comprising a flexible membrane covering an elastic blade adapted to connect terminals together when it is stressed by a user, i.e. when it is under pressure, and to prohibit any connection between the terminals when it is at rest.

[0007] Electronic devices often include a push button designed to be manipulated by the user so as to make contact with the flexible membrane of the switch, via a striker, in order to deform the elastic blade into its connection position.

[0008] When the electronic device is subjected to a shock at the push button, the elastic blade is likely to deform plastically under the effect of the forces applied to it, and consequently, it risks suffering irreversible damage.

[0009] One solution to avoid this problem is to increase the dimensions of the contact surface of the striker so that it distributes the transmitted forces as much as possible in order to reduce the pressure to which the elastic blade is subjected.

[0010] However, this solution may not be feasible for applications where dimensions are critical design constraints, for example in microelectronic or micromechanical fields, such as the watchmaking industry.

[0011] Furthermore, this solution may not be feasible, for example due to manufacturing constraints.

[0012] Another solution is to create an extra thickness in the flexible film. Since this film is generally made of silicone, this extra thickness is designed to deform elastically during an impact in order to absorb the forces.

[0013] However, such an extra thickness is unsuitable for absorbing significant forces, for example those generated by an impact corresponding to a deceleration of 5000G, as specified in the NIHS 91-30 standard. Indeed, the flexible film then deforms so much under the effect of the forces received and transmits them to the elastic blade and the terminal which deform plastically.

[0014] Document EP2607972 describes a control module for an electronic device with a push button comprising a striking element, a switch adapted to occupy an engaged state and a rest state, said striking element being configured to drive the switch into the engaged state or into the rest state when the push button is activated, the control module further comprising a stop member against which the striking element bears when driving the switch into the engaged state or into the rest state. Summary of the invention

[0015] In order to resolve the aforementioned drawbacks, the present invention relates to a control module according to claim 1.

[0016] It should be noted that, in the present invention, the stop element is separate from the switch. The switch can therefore advantageously be a standard, commercially available component.

[0017] The stop mechanism advantageously prevents the moving plunger from moving if excessive force is applied to the switch. This controls the maximum force that can be applied to the switch and protects it against excessive stress, such as that caused by impacts.

[0018] In particular embodiments, the invention may further comprise one or more of the following features, taken individually or in all technically possible combinations.

[0019] In particular embodiments, the striking element has an axial projection extending from a bearing surface with which it forms a shoulder. The striking element is configured such that, when it drives the switch into the connected or resting state, the axial projection applies pressure to the switch and the bearing surface rests against the stop member.

[0020] In certain embodiments, the stop member has the form of a wall fixed against the switch and includes a through opening designed to receive the axial protrusion of the push button when the striking element moves the switch to the on or off state. In other words, the axial protrusion of the push button is designed to engage through the opening in order to move the switch to the on or off state.

[0021] In particular embodiments, the switch comprises a frame, the stop member having a concavity arranged opposite the switch so that it bears on said frame by a peripheral area extending at the level of the periphery of the stop member.

[0022] In particular embodiments, the control module includes a damper configured to absorb part of the forces involved by deforming when the striking element drives the switch into the connected state or into the rest state, at least when said forces are greater than a predetermined threshold.

[0023] In particular embodiments, the damper is arranged on the bearing surface so as to be subjected to compression when the striking element drives the switch into the connected or rest state.

[0024] In particular embodiments, the damper is in the form of a washer made of elastically deformable material arranged around the axial protrusion.

[0025] In particular embodiments, the damper is intended to be arranged between a structure of the watch movement and the switch, in line with the direction of the pusher stroke.

[0026] In particular embodiments, the switch comprises a frame to which a spring blade and connection terminals are attached. The spring blade is moved into a connection position in which it makes contact between the connection terminals when the switch is in the connected state, and is moved into a rest position in which it prevents contact between the connection terminals when the switch is in the rest state. The stop is arranged in line with the direction of travel of the push button against one of the connection terminals such that the terminal is interposed between the stop and the striker element.

[0027] In particular embodiments, the pusher includes a spring interposed between the pusher head and the guide tube so as to constrain said pusher to move towards its rest position.

[0028] In particular embodiments, the striking element comprises a substantially cylindrical body including a radial dimension extending in a direction orthogonal to the direction of movement of the pusher, said radial dimension being less than the outside diameter of one end of the guide tube at which it is arranged.

[0029] In another aspect, the present invention relates to a watch comprising a case in which an electronic watch movement is housed. The latter includes a control module as described above, the pusher being engaged through a case-like structure, the switch and the stop being fixed to a structure of the watch movement. Brief description of the figures

[0030] Other features and advantages of the invention will become apparent from the following detailed description, given by way of non-limiting example, with reference to the accompanying drawings in which: there figure 1 schematically represents a cross-sectional view of a watch case housing an electronic watch movement comprising a control module according to a preferred embodiment of the invention and a detailed view of a switch on the control module; figure 2 represents a cross-sectional view of a watch case in which is housed an electronic watch movement comprising a control module according to another embodiment of the invention.

[0031] Note that the figures are not necessarily drawn to scale for reasons of clarity. Detailed description of the invention

[0032] In the examples of embodiments of the invention shown on the figures 1 and 2and described in this text, the invention is applied to the field of watchmaking. In particular, the invention relates to a control module 10 arranged here in an electronic watch movement housed in a watch case, having a case 20, and intended for the control of a function upon request for example from a user.

[0033] As seen on the figures 1 and 2 The control module 10 includes a push button 11 that moves in translation along a direction AA and is intended to be activated by the user. In the specific examples shown in the figures, the push button 11 is engaged through the housing 20 so as to be accessible to the user. Alternatively, the push button may be rotationally movable or, more generally, may be actuated by any type of movement.

[0034] The control module 10 further includes a switch 12 intended to be operated by a user upon activation of the push button 11 and a stop member 13 against which the push button 11 is intended to rest, i.e. to come into contact, when the switch 12 is activated.

[0035] In particular, the switch 12 is adapted to occupy a connected state and a rest state, the push button 11 being configured to, when it actuates said switch 12, drive it into one or the other of these states.

[0036] As schematically shown in the detailed view of the figure 1 In one embodiment of the invention, the switch 12 may comprise a frame 120 to which are attached an elastic blade 121 made of electrically conductive material and connection terminals 122 and 123. As seen in the detail view of the figure 1The switch 12 may include a connection terminal, referred to as the "center terminal" 122, arranged in the direction of travel of the push button 11, i.e., in alignment with direction AA, and one or more peripheral terminals 123. Preferably, the spring blade 121 is configured to occupy, when the push button 11 is activated by the user, a connection position in which it generates contact between the center terminal 122 and the peripheral terminal(s) 123. When activated and causing the spring blade 121 to move into the connection position, the push button 11 is configured to rest against the stop member 13.

[0037] In particular, when the user presses the push button 11, the latter applies pressure to the elastic blade 121, deforming it into an unstable planar position in which it is in contact with all the central terminals 122 and peripheral terminals 123. The elastic blade 121 is also configured to occupy, when the push button 11 is not pressed by the user, a stable rest position in which it prevents contact between the central terminal 122 and peripheral terminals 123. As can be seen in the detail view of the figure 1 , when in this position, the elastic blade 121 can be bent so as to be prestressed to exhibit elastic characteristics.

[0038] The switch 12 may also include a flexible membrane 124 covering the elastic blade 121, which the push button 11 is intended to press against when activated. However, this flexible membrane 124 is not essential to the invention.

[0039] In the preferred example of an embodiment of the invention shown in the figure 1 The pusher 11 rests directly against the stop member 13, as described in more detail below. In another embodiment shown in the figure 2 , the push button 11 rests indirectly against the stop member 13, the switch 12 being interposed between said push button 11 and said stop member 13.

[0040] As seen on the figures 1 and 2 , the switch 12 and the stop member 13 are intended to be fixed to a structure 21 of the clock movement, for example by any means known to a person skilled in the art.

[0041] The pusher 11 includes a pusher head 110 extending outside the case 20 and intended to be operated by the user. The pusher 11 also includes a striking element 111 connected to the pusher head 110 by means of a pusher rod 112 which slides within a guide tube 113 fixed in a through opening in the case 20. For example, the striking element 111 is screwed into the pusher rod 112, or is fixed by any suitable means within the reach of a person skilled in the art.

[0042] The guide tube 113 has, at one end, a first portion by which it is engaged in the through opening of the case 20, and has, at a second end, a second portion having a larger outside diameter than the first portion so as to form a shoulder with the latter. As shown in the figure 1The guide tube 113 is arranged to bear against the frame 20 by means of this shoulder. The pusher 11 includes a spring 114 working in compression, interposed between the pusher head 110 and the shoulder of the guide tube 113 so as to constrain the pusher 11 to move into a rest position.

[0043] As shown by figure 1 The striking element 111 rests against the first end of the guide tube 113 when the pusher 11 is in its rest position. In other words, when it rests against the stop member 13 and against the guide tube 113, the striking element 111 defines the end stops of the pusher 11.

[0044] The striking element 111 comprises a substantially cylindrical body including a radial dimension extending in a direction orthogonal to the direction AA, said radial dimension being advantageously less than the outside diameter of the first portion of the guide tube 113. This feature makes it easier to assemble the striking element 111 onto the pusher stem 112, insofar as it can be carried out before the pusher 11 is fixed to the case 20 of the watch, i.e. before it is engaged in the through opening of said case 20.

[0045] In the preferred example of implementation shown on the figure 1The body of the striking element 111 has an axial projection 115 extending from a bearing surface with which it forms a shoulder. The striking element 111 is configured so as to apply pressure, via the axial projection 115, to the elastic blade 121 when the pusher 11 is activated by the user, in order to deform it until it occupies the connection position and the bearing surface rests against the stop member 13.

[0046] In summary, the invention prevents excessive stress on the switch 12 because the stop 13 acts as a translational stop for the pusher 11 and transfers the forces received to the frame or, optionally, to the structure 21 of the watch movement. The invention also therefore allows control of the maximum force applicable to the switch 12, which is defined in particular by the length of the axial protrusion 115.

[0047] Advantageously, the control module 10 may include a damper 116 configured to absorb part of the forces involved, by deforming, at least when said forces are greater than a predetermined threshold, when the push button 11 actuates the switch 12. Preferably, it is made of elastically deformable material, such as elastomer, or has an elastically deformable structure, such as a compression spring.

[0048] In one embodiment of the invention, the damper 116 is arranged on the bearing surface so as to be subjected to compression when the elastic blade 121 is driven into the connection position as seen in the figures 1 and 2 In particular, in the preferred example of implementation shown on the figure 1 , the damper 116 is in the form of a washer arranged around the axial protrusion 115.

[0049] In another embodiment of the invention not shown in the figures, the damper 116 can be arranged between the structure 21 of the watch movement and the switch 12, along the extension of the direction AA. Thus, if the switch 12 were subjected to excessive forces, it would be able to transmit a portion of these forces by moving or deforming slightly locally within the damper 116, which would absorb the portion of the forces transmitted by the switch 12.

[0050] In the example implementation shown on the figure 1 The stop member 13 has the form of a wall having a stop surface 130 and through which a through opening 131 extends. When the pusher 11 is actuated, the bearing surface of the striking element 111 is provided to rest against the stop surface 130 and the axial protrusion 115 is provided to engage through the through opening 131.

[0051] Advantageously, in the preferred embodiment of the invention, the stop member 13 has a concavity 132 facing the switch 12, arranged so that the stop member 13 bears on the frame 120 of the switch 12 by a peripheral area extending to the periphery of said stop member 13. This feature makes it possible, on the one hand, to increase the resistance to mechanical stresses of the stop member 13, said stresses being directed towards its periphery, and on the other hand, to transmit the stresses generated by the activation of the push button 11 to the frame 120 of the switch 12. In other words, the forces generated by a possible impact are not transferred to the elastic blade 121 and to the central terminals 122 and peripheral terminals 123.

[0052] In the example implementation shown on the figure 2The stop 13 is arranged against the central terminal 122, either directly or indirectly, so that the latter is interposed between the stop 13 and the striking element 111 when the push button 11 is activated by the user. In other words, the stop 13 is arranged behind the central terminal 122, against it, considering that the front of the switch 12 is opposite the push button 11. This arrangement provides a translational stop if excessive force is applied to the switch 12, and in particular to the spring blade 121, preventing any deformation of the latter.

[0053] It should be noted that, in this example of implementation, as shown by the figure 2 , the stop member 13 is interposed between the central terminal 122 and the structure 21 of the clock movement.

[0054] More specifically, the stop member 13 comprises a base 133 arranged to bear against the structure 21 of the watch movement and from which extends an outgrowth 134 resting, by a free end, against the central terminal 122.

[0055] In this embodiment, the body of the striking element 111 does not have an axial protrusion 115. Indeed, as shown by the figure 2 , the body of the striking element 111 presents only a flat bearing surface intended to apply a force against the switch 12, and more specifically, against the elastic blade 121.

[0056] This embodiment is compatible with the design of the shock absorber 116 in which it is interposed between the structure 21 of the watch movement and the switch 12, extending along the direction AA. In this case, the base 133 is arranged to bear against the shock absorber 116. The invention is described in the context of its application to an electronic device consisting of a watch. However, it is understood that the invention is not limited to this application and could advantageously be used with any other portable or non-portable electronic device.

[0057] More generally, it should be noted that the implementation and realization methods considered above have been described as non-limiting examples, and that other variants are therefore conceivable, according to the claims.

Claims

1. A control module (10) designed to be arranged in an electronic horological movement turned in a watchcase with a middle (20), comprising a button (11) comprising a button head (110) designed to extend outside the middle (20) and to be operated by a user, the button (11) further comprising a striking element (111) connected to the button head (110) via a button arbor (112) slidably engaged in a guide tube (113) designed to be fastened in a through-opening in the middle (20), the control module (10) further comprising a switch (12) adapted to be in an on state and an off state, said striking element (111) being configured to drive the switch (12) into the on state or the off state when the button (11) is pressed, the control module being characterised by a stop organ (13) against which the striking element (111) bears directly or indirectly when it drives the switch (12) into the on state or into the off state.

2. The control module (10) according to claim 1, in which the striking element (111) has an axial projection (115) extending from a support surface with which it forms a shoulder, the striking element (111) being configured such that, when it drives the switch (12) into the on state or into the off state, the axial projection (115) applies pressure to the switch and the support surface rests against the stop organ (13).

3. The control module (10) according to claim 2, in which the stop organ (13) is in the form of a wall fastened against the switch (12) and comprising a through-opening designed to receive the axial projection (115) of the button (11) when the striking element (111) drives the switch (12) into the on state or the off state.

4. The control module (10) according to claim 3, in which the switch (12) comprises a frame (120), the stop organ (13) having a concavity arranged facing the switch (112) so that it bears on said frame (120) via a peripheral zone extending at the level of the periphery of the stop organ (13).

5. The control module (10) according to any of claims 1 to 4, comprising a shock absorber (116) configured to absorb part of the stresses in play by distorting when the striking element (111) drives the switch (12) into the on state or into the off state, at least when said stresses are above a predetermined threshold.

6. The control module (10) according to claim 5, in which the shock absorber (116) is arranged on the support surface of the striking element (111) so as to be biased in compression when the striking element (111) drives the switch (12) into the on state or into the off state.

7. The control module (10) according to claims 2 and any of claims 5 or 6, in which the shock absorber (116) is in the form of a washer made of a resiliently distortable material fitted around the axial protrusion (115).

8. The control module (10) according to claim 5, in which the shock absorber (116) is designed to be fitted between a structure (21) of the horological movement and the switch (12), in the extension of the direction of travel of the button (11).

9. The control module (10) according to claim 1, in which the switch (12) comprises a frame (120) to which a resilient blade (121) and connection terminals (122, 123) are fastened, the resilient blade (121) being moved into a connecting position in which it generates contact between the connection terminals (122, 123) when the switch (12) is in the on state, and being moved into a locked state in which it prevents contact between the connection terminals (122, 123) when the switch is in the off state, the stop organ (13) being arranged in the extension of the direction of travel of the button (11) against one of the connection terminals (122, 123) so that the latter is inserted between the stop organ (13) and the striking element (111).

10. The control module (10) according to claim 9, in which the striking element (111) comprises a body with a substantially cylindrical shape comprising a radial dimension extending in a direction orthogonal to the direction of travel of the button (11), said radial dimension being less than the outer diameter of one end of the guide tube (113) at which it is arranged.

11. The control module (10) according to any of claims 1 to 10, in which the button (11) comprises a spring (114) inserted between the button head (110) and the guide tube (113) to cause the button (11) to move to a lock position.

12. A watch comprising a case in which an electronic horological movement is turned, the watch being characterised in that the latter comprises a control module (10) according to any of claims 1 to 11, the button (11) being engaged through a middle (20) with which the case is fitted, the switch (12) and the stop organ (13) being fastened to a structure (21) of the horological movement.