Push-button arrangement for an electronic or electromechanical wristwatch

Abstract

A push-button arrangement includes an electronic plate. The push-button is of the type surface mounted on a flexible printed circuit sheet that is itself partially fixed to the electronic plate. A portion of the flexible printed circuit sheet that carries the push-button remains free and is folded around a peripheral edge of the electronic plate, such that the push-button extends substantially perpendicularly to the electronic plate and bears against a lateral surface of the electronic plate.

Claims

1. A push-button arrangement comprising: an electronic plate; a flexible printed circuit sheet partially fixed to the electronic plate; and a push-button welded flat on a surface of a free portion of the flexible printed circuit sheet, wherein the free portion of the flexible printed circuit sheet is not fixed to the electronic plate, and wherein the free portion of the flexible printed circuit sheet extends around a peripheral edge of the electronic plate, such that the push-button is placed in a vertical plane, substantially perpendicularly to the electronic plate and bears against a lateral surface of the electronic plate.

2. The push-button arrangement according to claim 1, wherein the push-button is disposed in a housing arranged in the electronic plate, and wherein the housing limits a displacement of the push-button horizontally forwards and backwards, and vertically downwards.

3. A portable object comprising: a case which is housing the push-button arrangement according to claim 1, wherein the case of the portable object is pierced with a through hole inside which slides a stem of an external push-button, wherein the stem is held in a rest position by an elastic device that pushes the stem outwards, and wherein the stem is moved into an operating position in which the stem presses on the surface mount push-button by pressure applied to the stem.

4. A push-button arrangement comprising: an electronic plate; a flexible printed circuit sheet, partially fixed to the electronic place; and a push-button mounted to a surface of the flexible printed circuit sheet is disposed in a housing arranged in the electronic plate, wherein the housing limits a displacement of the push-button horizontally forwards and backwards, and vertically downwards, wherein the housing is covered by an additional plate that limits the displacement of the push-button vertically upwards, and wherein a free portion of the flexible printed circuit sheet where the push-button is mounted is folded around a peripheral edge of the electronic plate, such that the push-button extends substantially perpendicularly to the electronic plate and bears against a lateral surface of the electronic plate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other features and advantages of the present invention will appear more clearly from the following detailed description of an example embodiment of a push-button arrangement according to the invention, this example being given solely by way of non-limiting illustration with reference to the annexed drawing, in which:

(2) FIG. 1, cited above, illustrates a push-button arrangement surface mounted on an electronic plate according to the prior art.

(3) FIG. 2 is a vertical cross-sectional view of an electronic plate on which a flexible printed circuit sheet is fixed, a portion of the flexible printed circuit sheet being left free and carrying a push-button and being folded such that the push-button extends vertically, bearing against the side of the plate.

(4) FIG. 3 is a top view of the electronic plate on which is fixed the flexible printed circuit sheet, wherein the additional plate that covers the housing in which the push-button is disposed has been removed.

(5) FIG. 4 is a vertical cross-sectional view of the electronic plate illustrated in FIG. 2, this electronic plate being housed inside the case of a portable object which is pierced with a through hole inside which a stem of an external push-button is arranged to slide between a rest position and an operating position in which it presses on the surface mount push-button.

DETAILED DESCRIPTION OF ONE EMBODIMENT OF THE INVENTION

(6) The present invention proceeds from the general inventive idea consisting in fixing a surface mount push-button onto a flexible printed circuit sheet, which is itself partly fixed to an electronic plate housed inside the case of a portable object, such as an electronic or electromechanical wristwatch. The printed circuit sheet is arranged on the electronic plate such that the portion of the printed circuit sheet that carries the push-button remains free and can be folded around the edge of the electronic plate to move the push-button into a vertical plane in which the push-button bears against the side of the electronic plate.

(7) A push-button arrangement according to the invention is illustrated in FIG. 2, annexed to this Patent Application. Designated as a whole by the general reference numeral 16, this push-button arrangement comprises an electronic plate 18 delimited by a peripheral edge 20 and a lateral surface or side 22. Such an electronic plate 18 is intended to receive on its upper surface 24 a set of electronic components connected to each other by electrically conductive paths and required for the operation of a portable object, such as a wristwatch, in which electronic plate 18 is incorporated.

(8) As revealed by an examination of FIG. 2, a flexible printed circuit sheet 26 is partly fixed to the upper surface 24 of electronic plate 18, whereas the portion 28 of flexible printed circuit sheet 26 that carries a surface mount push-button 30 remains free. The free portion 28 of flexible printed circuit sheet 26 is folded around the peripheral edge 20 of electronic plate 18, such that push-button 30 is in a vertical plane bearing against the side 22 of electronic plate 18. As can be seen in FIG. 2, the free portion 28 of flexible printed circuit sheet 26 that carries push-button 30 is sufficiently long to be able to be folded downwards around peripheral edge 20 of electronic plate 18, then upwards to form a V-shaped fold 32. It goes without saying, however, that this embodiment is given purely by way of non-limiting illustration and that free portion 28 of flexible printed circuit sheet 26 need only be sufficiently long to be folded downwards around peripheral edge 20 of electronic plate 18 and to bring push-button 30 into a vertical plane in which it presses against the side 22 of electronic plate 18.

(9) According to an advantage of the invention, push-button 30 is welded flat onto flexible printed circuit sheet 26. Consequently, when flexible printed circuit sheet 26 is fixed to upper surface 24 of electronic plate 18 and then folded downwards to place push-button 30 in a vertical plane bearing against side 22 of electronic plate 18, the welds 34 via which push-button 30 is secured to flexible printed circuit sheet 26 are subjected to compression and not shear stress when push-button 30 is pressed, such that the risk of these welds 34 yielding is almost totally removed. It will also be noted that, since push-button 30 is bearing against side 22 of electronic plate 18, this provides good mechanical resistance to pressure and allows good positioning tolerances to be obtained in the vertical plane. Finally, as push-button 30 can be flat welded onto flexible printed circuit sheet 26, this considerably facilitates manufacturing operations.

(10) A careful examination of FIGS. 2 and 3 also reveals that preferably, but not limitatively, push-button 30 is disposed inside a housing 36 arranged in lateral surface 22 of electronic plate 18. This housing 36 is delimited by a vertical side wall 38 which surrounds push-button 30 and which is forwardly extended by a horizontal surface 40. This horizontal surface 40, delimited by an edge portion 42, acts as a bearing surface for push-button 30. Housing 36 thus limits the displacement of push-button 30 horizontally forwards and backwards, and vertically downwards.

(11) Additionally, it is possible (see FIG. 2) to cover housing 36 with an additional plate 44, such that the displacement of push-button 30 is also limited upwards.

(12) As represented in FIG. 4, the push-button arrangement 16 according to the invention is intended to be housed inside a case 46 of a portable object, such as a wristwatch. This case 46 includes a case middle 48 which is pierced with a through hole 50, inside which a stem 52 of an external push-button 54 is arranged to slide between a rest position, in which stem 52 is held by elastic means 56 which push it outwards, and an operating position in which, by pressure on stem 52, the latter presses on push-button 30.

(13) It goes without saying that this invention is not limited to the embodiment that has just been described and that various simple modifications and variants can be envisaged by those skilled in the art without departing from the scope of the invention as defined by the annexed claims.

NOMENCLATURE

(14) Push-button 1 Electronic plate 2 Case 4 Support 6 Branches 6a, 6b Upper surface 8 Weld spots 10 Play 12 Lateral surface 14 Push-button arrangement 16 Electronic plate 18 Peripheral edge 20 Lateral surface or side 22 Upper surface 24 Flexible printed circuit sheet 26 Free portion 28 Push-button 30 V-shaped fold 32 Welds 34 Housing 36 Vertical side wall 38 Horizontal surface 40 Edge portion 42 Additional plate 44 Case 46 Case middle 48 Through hole 50 Stem 52 External push-button 54 Elastic means 56