EP1515203A1 - Manufacturing and assembly method of electrical contacts for delicate switches used in timepieces - Google Patents

Abstract

The method involves stamping and pre-shaping a conductive material plate to form an intermediate base plate having a support structure (25). Electric contact strips are coupled to each other at points of attachment in the structure. The plate with the strips is placed so that each strip is held between two support pieces. Points of attachment are broken to make the strips independent and electrically insulated from each other.

Description

TECHNICAL AREA

The present invention relates to a method of manufacture and assembly of electrical contacts for small control members, in particular for control members used in watchmaking. The present invention particularly relates to such a method for producing a crown rod multifunctional timepiece or other electromechanical or electronic apparatus similar.

TECHNOLOGICAL BACKGROUND

Conventionally, electrical contacts of control devices (eg ex. pushbuttons, crown rods or the like) are designed in the form of a movable part that can be actuated by the control member for selectively establish an electrical connection with another part, generally fixed, electrical contact. The moving part of the electrical contact is typically realized in the form of a contact blade cut from a plate of a material electrically conductive (usually a metal such as steel or copper) and folded to the desired shape. Each contact blade thus formed is then mounted and fixed to vicinity of the control member. This operation is for example carried out at the by hand or automatic assembly processes consisting essentially of the gripping by a manipulator of the contact blade (the contact blades being typically arranged in bulk or as a strip in a feeder) and its mounting by the manipulator on its final support with which the contact blade is made solidary.

As long as the contact blades are of a reasonable size and their configuration is not too complex, editing operations do not pose usually no problem. This is not the case, however, since the contact blades have a very small size making their handling difficult for both an operator and a machine. To this are added additional constraints when a plurality of contact blades must be mounted with a relatively high precision, some by compared to others. This is particularly the case for the manufacture and assembly of electrical contacts for multifunction control devices. We think particular to multifunctional crown rods whose rotations and positions axial are detected and translated by means of a plurality of electrical contacts.

STATEMENT OF THE INVENTION

A general object of the present invention is to propose a solution making it easier to manufacture and install contacts electrical controls of small dimensions. The present invention aims in particular to simplify the manufacture and assembly of electrical contacts control organs used in watchmaking.

For this purpose, the subject of the present invention is a method of manufacturing and mounting of electrical contacts for small control members whose characteristics are set forth in claim 1.

The method thus comprises a first stage of stamping and preforming of a plate of an electrically conductive material to form a plate of intermediate base comprising a support structure and a plurality of electrical contact still mechanically linked to the support structure by a plurality of attachment points, each electrical contact blade comprising a base and a flexible extension connected to the base to form the movable portion of a contact electric actuated by a control member. This first step is followed by a step of positioning the intermediate base plate on a first electrically isolated support part of the electrical contact blades, and by a fixing step on the first support piece of a second support piece electrically isolated from the electrical contact blades so that each of the electric contact blades is held between the first and second pieces of support by its base. Finally follows a step of breaking the plurality of attachment points connecting the plurality of electrical contact blades to the support structure so that all electrical contact blades are made independent and isolated electrically from each other.

It will be understood that this method makes it possible to manufacture and mount with a more great simplicity of electric contact blades of small dimensions. Indeed, when positioning and fixing of the electrical contact blades, the latter are still linked together by the support structure. This support structure can thus be handled with electric contact blades with greater ease. On the other hand, the accuracy of the relative positioning of the various blades of electrical contact is ensured by the fact that the contact blades are still linked together during the fixing step.

According to one embodiment, the aforementioned method is implemented particularly for the realization of a piece multifunction crown rod watchmaking. According to this exemplary embodiment, the stamping and preforming step includes the preparation of a first set of electrical contact blades for detection of rotations of the crown rod and a second set of electrical contact blades for the detection of axial positions of the crown rod. Preferably, the stem-crown has an electrically insulated end for actuating the blades of electrical contact, this end having a first part with a non-constant radius forming a cam for actuating the first set of electric contact blades and a second part comprising several cylindrical portions of different diameters for actuating the second set of electrical contact blades.

In the context of the aforementioned embodiment, the first set of blades contact point advantageously comprises first and second blades of electrical contact placed on either side of the stem crown, the extensions hoses of the first and second electrical contact blades being oriented substantially perpendicular to the axis of the stem-crown and axially offset relative to the stem-crown so as to be able to translate the rotations of the stem crown in the form of electrical signals. Similarly, the second set of blades electrical contact advantageously comprises first and second blades of electrical contact placed on either side of the stem crown, the extensions hoses of the first and second electrical contact blades being oriented substantially parallel to the axis of the crown rod and offset axially by relative to the stem-crown so as to be able to translate the axial positions of the stem-crown in the form of electrical signals.

Other advantageous embodiments are the subject of the claims dependent.

SUMMARY DESCRIPTION OF THE DRAWINGS

• la figure 1a est une vue en plan d'ensemble d'une tige-couronne multifonction comprenant un jeu de quatre contacts électriques fabriqués et montés selon un mode de mise en oeuvre de l'invention ;
• la figure 1 b est une vue en plan agrandie de la figure 1a où les éléments masquant les contacts électriques ont été supprimés pour faire apparaítre les lames de contact électrique actionnées par la tige-couronne ;
• la figure 2 est une vue en perspective des lames de contact électrique de la tige-couronne multifonction de la figure 1, illustrées dans une configuration avant montage où elles sont encore solidaires d'une structure de support conformée avantageusement en bande, cette bande comportant plusieurs jeux de lames de contact électrique identiques ;
• les figures 3a à 3f illustrent chronologiquement une succession d'étapes mises en oeuvre en vue de la fabrication et du montage des contacts électriques pour la réalisation de la tige-couronne multifonction de la figure 1 a.

Other characteristics and advantages of the present invention will appear more clearly on reading the following detailed description of embodiments of the invention given solely by way of nonlimiting examples and illustrated by the appended drawings in which:

• Figure 1a is an overall plan view of a multifunction crown rod comprising a set of four electrical contacts manufactured and mounted according to an embodiment of the invention;
• Figure 1b is an enlarged plan view of Figure 1a where the elements masking the electrical contacts have been removed to reveal the electric contact blades actuated by the stem crown;
• FIG. 2 is a perspective view of the electric contact blades of the multifunctional crown rod of FIG. 1, illustrated in a configuration before mounting where they are still integral with a support structure advantageously shaped in a strip, this strip comprising several sets of identical electrical contact blades;
• FIGS. 3a to 3f chronologically illustrate a succession of steps implemented with a view to manufacturing and assembling the electrical contacts for producing the multifunctional crown rod of FIG. 1a.

DESCRIPTION OF MODES OF IMPLEMENTATION OF THE INVENTION

The figures illustrate an example of a particular implementation of the invention for the realization of a multifunctional crown rod of a timepiece or other electromechanical or similar electronic apparatus. As will be seen below in detail, the invention can however be implemented in the context of the manufacture and mounting electrical contacts for other types of control members, such pushbuttons or similar control devices operating one or several electrical contacts to translate the movement or position of the organ of ordered. By way of example, the control member could be of a similar type to a two-axis joystick. It should therefore be made clear that the invention is not limited the only realization of multifunctional crown rods as described below. By elsewhere, although a particularly interesting application of the invention is the production of control units for timepieces, the invention could be applied in other areas, such as the manufacture of control portable electronic instruments (PDAs, phones cell phones, etc.).

Figure 1a is a plan view showing an overview of a crown rod Multifunction. By "multifunctional stem-crown" is meant here an organ of control comprising a rod (designated by reference numeral 1 in the figures) that can be manipulated by the user through a crown (designated by reference numeral 10 in Figure 1a) integral with the rod 1 and whose direction of rotation and / or axial positions are translated into electrical signals through a plurality of electrical contacts actuated by the rod 1. These electrical contacts are arranged and arranged in the form of a compact module generally designated by the reference numeral 2 placed at the end of the rod 1 located opposite the crown 10. The rod 1 further comprises an annular groove 3 intended to accommodate a seal toric (not shown) provided for sealing between the rod 1 and the box (no represented) through which the rod 1 penetrates.

In the example shown, the rod 1 is likely to occupy four positions distinct axial positions, namely a neutral position, two stable positions called "drawn" and an unstable position called "push", and can also undergo rotations in clockwise and counter-clockwise. In Figures 1a and 1b, the rod 1 is illustrated in its extreme position pulled.

The four axial positions and the direction of rotation of the rod 1 are translated into electrical signals through two sets of independent electrical contacts. The first set of electrical contacts comprises in particular two contact blades 21, 22 to translate the direction of rotation of the rod 1, each contact blade electrical 21, 22 delivering an electrical signal composed of an alternation of levels binary logic ("enabled" or "disabled" states) to distinguish between the two directions of rotation of the rod 1. The second set of electrical contacts comprises in particular two electric contact blades 23, 24 to translate the four positions axial of the rod 1, each electric contact blade 23, 24 delivering a signal binary logic type electrical which is a function of the axial position of the rod.

The end of the rod 1 and the electrical contact blades 21 to 24 are covered by a cover 7 made of an electrically insulating material (one piece advantageously made by molding a plastic) and which is made integral with a support plate generally designated by reference numeral 4. The face 7a upper cover 7 comprises a recess 70 of particular shape forming a housing for a spring element 9 open. This spring element 9 has a shape particular bend, known from the prior art, adapted to maintain the rod 1 in its three stable axial positions. This spring 9 is conventionally arranged to cooperate with three adjacent annular grooves formed on the body of the rod 1 and separated by beads. These annular grooves and beads are not referenced but appear clearly in Figure 1b. The spring 9 thus comprises two free ends 9a, 9b (oriented substantially perpendicular to the plane illustrations of Figures 1a and 1b) which extend inside the module 2, from and other of the rod 1. During an axial displacement of the rod 1, the free ends 9a and 9b spring 9 spread by sliding on the beads before closing on one of the annular grooves of the stem 1.

The aforementioned support plate 4 here consists of two parts superimposed. A first lower part (or base plate) 5 is made in one electrically conductive material and is intended to be carried to a potential determined electrical power, for example the electrical potential forming the mass of a electronic module with which the control member must cooperate. A second upper part 6 is made of an electrically insulating material and is interposed between the base plate 5 and the various electrical contact blades 21 to 24 above. As such, the support plate 4 can be considered as a support piece electrically insulated from the electrical contact blades 21 to 24. This support piece 4 can obviously take various forms.

The use of the above-mentioned electrical contacts for the interpretation of direction of rotation and axial positions of a rod is already well known on the functional. The configuration of the electrical contact blades 21 to 24 is however and has already been the subject of two European patent applications at the end of the name of this Deponent entitled respectively "Control Device to multiple axial positions for electronic device "(European patent application No. 02080681.6 filed December 31, 2002) and "Rotary control device for electronic apparatus "(European Patent Application No. 03011618.0 filed on May 22, 2003). We will only recall here the elements and characteristics related to the subject of the present invention.

Figure 1b allows to better highlight the shape and configuration particular electric contact blades 21 to 24. In this figure 1b, the cover 7 and the spring 9 have not been shown to discover the four contact blades 21 to 24. However, the free ends 9a, 9b of the spring are shown in section to illustrate their arrangement with respect to the annular grooves of the rod 1.

From the foregoing, it will be understood that the four electrical contact blades 21 to 24 are interposed between the support plate 4, on the one hand, and the cover 7, on the other hand go. In this case, each of the electrical contact blades has a portion forming base (denoted by the numerical reference of the concerned blade followed by the index a) sandwiched between the support plate 4 and the cover 7.

Each of the electric contact blades 21 to 24 further comprises a first flexible extension (designated by the numerical reference of the blade concerned followed by the index b) connected to the base of the blade and which is likely to move freely inside the hood 7 under the action of the rod 1. This first flexible extension of each electric contact blade forms, strictly speaking, the moving part of each of the four electrical contacts.

As can be seen in Figures 1a and 1b, each of the blades of electrical contact 21 to 24 furthermore comprises an additional extension (designated by the numerical reference of the concerned slide followed by the index c) which is accessible from the outside of the hood 7. Each of these additional extensions 21c to 24c effectively forms the output terminal of each of the four electrical contacts, that is to say a terminal on which an electrical signal is delivered representative of the state (closed / open) of the corresponding electrical contact. These additional extensions 21c to 24c may advantageously have a shape terminal "U" (apparent in particular in Figures 2 and 3b) in the optics of being inserted into corresponding metallised holes in a wafer of printed circuit board (not shown) to which the control device is to be connected electrically.

In addition to the bases 21a to 24a, the flexible extensions 21b to 24b and the terminals output 21c to 24c, the electric contact blades 21 to 24 are still present in this example of the terminations 21d, 22d, 23d, 24d, respectively, leading to 7. These terminations 21d to 24d have no real utility from the point from the point of view of the electrical operation of the four contacts. As will be seen below, these terminations are the result of the implementation of the method of manufacture and assembly of electrical contacts according to the invention.

Before addressing in detail the description of this process of manufacture and montage, we will briefly explain the mode of actuation of the four electrical contacts by the rod 1.

In the particular embodiment shown in the figures, the flexible extensions 21b to 24b electrical contact blades 21 to 24 are each arranged to be brought into contact with the base plate 5 under the action of the rod 1 in order to establish an electrical connection with this base plate. mentioned above, in operation, the base plate is brought to a potential determined electric, for example an electrical potential forming mass. When one of the flexible extensions 21b to 24b is brought into contact with the base plate 5, the electric potential of this base plate 5 is then brought to the blade of corresponding contact and this state can be detected on the output terminal 21 d, 22d, 23d, 24d of the corresponding electrical contact.

In the exemplary embodiment illustrated, the end at least of the rod 1 which cooperates with the four electrical contact blades 21 to 24 is isolated electrically, here by an insulating sheath 30, the body of the rod 1 thus not being direct electrical contact blades 21 to 24. This insulating sheath 30 has a first portion 31 with a non-constant radius forming a cam (for example a part of rectangular section or elliptical section) for actuation of the first set of blades of electrical contact 21, 22 and a second portion 32 essentially comprising two cylindrical portions 32a, 32b of different diameters for actuating the second set of electric contact blades 23, 24.

The first 21 and second 22 electrical contact blades of the first game are placed on either side of the rod 1, the flexible extensions 21b, 22b of these contact blades 21, 22 being oriented substantially perpendicular to the axis of the rod 1 and axially offset relative to the rod 1 so as to be able to translate the rotations of the rod 1 in the form of electrical signals. The extensions 21b, 22b are therefore oriented in opposite directions. The extensions 21b, 22b are by elsewhere bent at a point designated by the reference numeral 210, resp. 220, (cf. in particular Figures 2 and 3b) so as to be directed out of the plane where the blades are supported, in the direction of the axis of the rod 1 (the rod 1 resting at a certain distance above the electric contact blades). In this area, the plate support 4 is devoid of insulation, an opening 61 being provided at this point in the insulating layer 6 to expose a portion of the base plate 5. Note still two through holes 41, 42 are formed in the support plate 4 (through the base plate 5 and the insulating layer 6) where are formed the ends 21c, 21d and 22c, 22d of the blades 21, 22.

Under the action of the rod 1, in this case during a rotation of the rod 1 around its axis, the cam portion 31 of the sheath 30 actuates successively the two flexible extensions 21b, 22b of the contact blades 21, 22, causing a slight downward movement of the points 210, 220 where the flexible extensions 21 b, 22b are bent. These points 210, 220 are then brought into contact with the plate of base 5 through the opening 61 formed in the insulating layer 6. Preferably, two bosses 51, 52 are arranged opposite points 210, 220 where the extensions 21b, 22b are bent (these bosses 51, 52 are indicated in lines interrupted in Figure 1 (b).

The first 23 and second 24 electrical contact blades of the second set are placed on either side of rod 1, this time in the vicinity of the end of the rod 1 and the portion 32 of the sheath 30. In this example, the flexible extensions 23b, 24b of these blades 23, 24 (at least the parts endings of these extensions that cooperate with the rod 1) are oriented substantially parallel to the axis of the rod 1 and again axially offset by relative to this rod 1 so as to translate the axial positions of the rod 1 in the form of electrical signals. Part of each flexible extension 23b, 24b is arranged to cooperate with the end 32 of the sheath 30 placed on the rod, then that another neighboring part of each flexible extension 23b, 24b is arranged to cooperate with a contact pad 53, resp. 54, coming from material with the plate of base 5. At this point, the support plate 4 is again provided with an orifice 43 through which open the extensions 23c, 23d, 24c and 24d blades 23, 24. The contact pads 53, 54 are here made in the form of extensions of the base plate 5 folded through the hole 43 in the direction of the rod 1. These pads contact 53, 54 are also visible in Figures 3d to 3f.

It should be noted that the flexible extensions 23b, 24b are configured and prestressed to come into contact laterally with the contact pads 53, 54 as shown in Figure 1b. This contact is maintained as long as rod 1 is not brought into a position where its end exerts an action to spread the blade corresponding. In the illustrated position (extreme pulled position), the two blades 23, 24 are in contact with the contact pads 53, 54. In the stable axial position intermediate (intermediate pulled position), the blade 23 is spaced from the contact pad 53. In the last stable axial position (neutral position), the two blades 23, 24 are spaced contact pads 53, 54. Finally, in the unstable pushed position (position accessible from the aforementioned neutral position), the blade 23 enters temporarily in contact with the stud 53 to be discarded again after return to the neutral position, this return being ensured by the restoring force of the spring 9.

We will not dwell on the description of the operation of the electrical contacts, this operation not being directly related to the subject matter of the claimed invention.

With reference to Figures 2 and 3a to 3f, we will now describe a mode implementation of the present invention for the manufacture and assembly of electrical contacts of the aforementioned multifunctional rod-crown.

In a general way, the proposed process proceeds in the manner next. This process begins with the stamping and preforming of a plate of an electrically conductive material to form a base plate intermediate comprising a support structure and a plurality of electrical contact still mechanically linked to the support structure by a plurality of attachment points (see Figure 2), each electrical contact blade comprising a base and a flexible extension connected to the base to form the part mobile of an electrical contact operable by the control member. Then follow a positioning step (see FIGS. 3a and 3b) of the intermediate base plate on a first support piece electrically insulated from the contact blades, a fixing step (see FIGS. 3c, 3d and 3e) on the first support piece of a second support piece electrically insulated from the contact blades so that each of the electric contact blades is maintained between the first and second pieces of support by its base, and finally a step of rupture (cf figure 3f) of the plurality of attachment points connecting the plurality of electrical contact blades to the support structure so that all electric contact blades are made independent and electrically isolated from each other.

The first stage of stamping and preforming is preferably carried out to produce a band comprising a plurality of identical sets of electric contact blades. This is for example the case in the example of setting work that will now be described. FIG. 2 shows indeed a band 200 in electrically conductive material (for example a metal of the steel type or copper) comprising several identical sets of blades 21 to 24 for producing the electrical contacts of the aforementioned multifunctional stem-crown (several games similar are thus made on the strip 200, only two being illustrated in FIG. Figure 2). This band 200 is obtained according to conventional stamping methods. Several orifices 250 are provided on the strip 200 to allow its handling and / or its positioning. In the configuration illustrated in FIG. note that each of the electric contact blades 21 to 24 is mechanically linked to a support structure 25 to form the band 200, the extensions 21d to 24d aforementioned forming points of attachment between the blades 21 to 24 and the structure of support 25.

FIG. 3a shows a perspective view of the cover 7 already mentioned, this FIG. 3a showing the rear face 7b of the cover 7. In this view, we can see by elsewhere the orifice 7c through which the rod 1 is housed once mounted, and several mounting posts 75, 76, 77. The four pins 75 are intended for allow the attachment of the cover 7 to the support plate 4 through holes of assembly 45 as will be seen below, while the pins 76, 77 are intended for ensure proper positioning of the cover 7 on the support plate 4. In this For example, the cover 7 advantageously still has a set of impressions 71 to 74 corresponding to the general shape of the bases 21a to 24a of the four contact blades 21 to 24. These fingerprints promote a good hold of the various blades to mounted state. Note that openings (not referenced) are also arranged to allow the passage of flexible extensions 21b to 24b blades electrical contact 21 to 24 inside the cover 7. It should be noted that the impressions could be carried out in one or other of the support pieces.

FIG. 3b shows a next step of the method where the strip 25 comprising the blades 21 to 24 is positioned on the cover 7. It can thus see the bases 21 b to 24b blades embedded in the footprints 71 to 74 corresponding.

After positioning the blades 21 to 24 on the cover 7, the insulating layer 6 and the base plate 5 are then positioned on the strip to form the plate support 4 (FIGS. 3c and 3d). After mounting the base plate 5, we will note that the tenons 75, 76, 77 of the cover 7 are housed in the mounting orifices 45, 46, 47 corresponding and that the openings 41, 42, 43 formed in the wafer support 4 provide access to the attachment points 21d to 24d of the contact blades Electric 21 to 24.

As illustrated in FIG. 3e, the ends 75 of the tenons are then plastically deformed to make integral the cover 7 and the support plate 4 and maintain the various contact blades 21 to 24. It will be understood that the cover 7 could be made integral with the support plate 4 by other means (e.g. welding, gluing, clipping, screwing, etc.).

As shown in Figure 3f, the electrical contact blades 21 to 24 can then be detached from the support structure 25 to be rendered independent and electrically isolated from each other. In the example, this is advantageously achieved by using a tool (not shown) to break the various fastening points 21d to 24d of the blades through the orifices 41, 42 and 43 provided to facilitate this operation. In order to ensure a facilitated breaking of points of fasteners, the section of the contact blades can be reduced locally to favor the cutting of the blade along a determined line.

The various electrical contacts of the control member are thus made. he all that remains is to mount the control unit strictly speaking (in the occurrence, the rod 1 provided with its crown 10 as well as the spring 9 of axial positioning of the rod 1) and to make the electrical connections between the output terminals of the electrical contacts and the appropriate electronic module. In the case in point, it will be noted that the rod 1 and the ring 10 are typically mounted at an ultimate stage of manufacture, in this case after assembly of the movement of the timepiece and insertion in its box.

It will be understood in general that various modifications and / or obvious improvements for the skilled person can be made to the modes embodiment described in the present description without departing from the scope of the invention defined by the appended claims. As already mentioned in the preamble, the invention is not limited to making electrical contacts for crown rods multifunctional but may apply by analogy to the achievement of any electrical contact for a small control member, for example for pushbuttons or control devices of a similar type to joystick. It will further be understood that the method could be exploited for manufacture and assemble simultaneously the electrical contact (s) of several control organs.

Claims (10)

Method for manufacturing and assembling electrical contacts for small-sized control members, in particular for control members used in watchmaking, characterized in that it comprises the following steps: a) stamping and preforming a plate of an electrically conductive material to form an intermediate base plate (200) comprising a support structure (25) and a plurality of electrical contact blades (21 to 24) still mechanically bonded to said support structure (25) by a plurality of attachment points (21d-24d), each electrical contact blade comprising a base (21a-24a) and a flexible extension (21b-24b) connected to said base for forming the movable portion of an electrical contact operable by a control member (1, 10); b) positioning the intermediate base plate (200) on a first support member (7) electrically insulated from said electrical contact blades (21-24); c) fixing on said first support member (7) a second support piece (4) electrically insulated from said electrical contact blades (21 to 24) so that each of said electrical contact blades (21 to 24) is maintained between said first (7) and second (4) support pieces by its base (21a to 24a); and d) breaking said plurality of attachment points (21d-24d) connecting the plurality of electrical contact blades (21-24) to said support structure (25) so that all electrical contact blades (21-24 ) are made independent and electrically isolated from each other. Method according to claim 1, characterized in that said first or second support piece (7, 4) has orifices (41, 42, 43) arranged for facilitating breaking of said plurality of attachment points (21d to 24d). A method according to claim 1 or 2, characterized in that said step of attaching the second support member (4) to the first support member (7) includes welding, gluing, clipping, screwing or riveting said first and second support pieces. Method according to any one of the preceding claims, characterized in that said second support piece (4) comprises a base (5) made of an electrically conductive material covered with an insulating material (6), said base (5) being intended to be brought to a determined electrical potential to act as a contact area common to each of said electrical contact blades (21 to 24) and with which each of the flexible extensions (21b to 24b) of said electrical contact blades can be brought into contact to establish an electrical connection, each of said electrical contact blades (21 to 24) further comprising an additional extension (21d to 24d) forming an output terminal for each electrical contact. Method according to any one of the preceding claims, characterized in that said first or second support piece (7, 4) comprises a plurality of impressions (71 to 74) in which these bases (21a to 24a) are drowned. electrical contact blades (21 to 24) during the fixing step. Method according to any one of the preceding claims, characterized in that the section of said electrical contact blades (21 to 24) is locally reduced at said attachment points (21 d to 24 d) to facilitate the cutting of the contact blades electric (21 to 24) during the breaking step. A method as claimed in any one of the preceding claims, characterized in that said stamping and preforming step includes preparing a strip (200) comprising a plurality of identical sets of electric contact blades (21 to 24). Process according to any one of the preceding claims, for the production of a multifunction crown rod (1, 10) of a timepiece, characterized in that said stamping and preforming step includes the preparation of a first electric contact blade set (21, 22) for detecting rotations of said crown rod and a second set of electrical contact blades (23, 24) for detecting axial positions of said crown rod. Method according to claim 8, characterized in that said crown rod (1, 10) has an electrically insulated end (30) for actuating said electric contact blades (21 to 24), said end (30) having a first part ( 31) having a non-constant cam-forming radius for actuating said first set of electric contact blades (21, 22) and a second portion (32) comprising a plurality of cylindrical portions (32a, 32b) of different diameters for actuating said second set of electric contact blades (23, 24). Method according to claim 9, characterized in that said first set of electrical contact blades comprises first (21) and second (22) electric contact blades placed on either side of the stem-crown (1, 10) the flexible extensions (21b, 22b) of said first and second electrical contact blades (21, 22) being oriented substantially perpendicular to the axis of the shank and offset axially with respect to the shank so as to be able to translate the rotations of said stem-crown into electrical signals,
and in that said second set of electrical contact blades comprises third (23) and fourth (24) electric contact blades placed on either side of the crown rod (1, 10), the flexible extensions (23b , 24b) said third and fourth electrical contact blades (23, 24) being oriented substantially parallel to the axis of the shank-crown and axially offset relative to the shank-crown so as to be able to translate the axial positions of said shank -couronne in the form of electrical signals.

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