Abstract:
The invention relates to a control device for a contactor, in particular for scrolling through a menu which allows appliances in a motor vehicle to be controlled.  
     It comprises a control key ( 36 ) mounted pivoting on a support, at least one contactor ( 4 ), and a tie bar ( 20, 22 ) interposed between the key ( 36 ) and each contactor ( 4 ). A, preferably transparent, transmitter ( 16 ) is formed by a supporting structure ( 18 ) and at least one tie bar ( 20, 22 ). The tie bars are connected to the supporting structure by at least one flexible arm so as to transmit to the contactor an action performed on the key ( 36 ). The supporting structure ( 18 ) serves as a support and a pivot for the control key ( 36 ).

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to a control device for a contactor.  
           [0002]    More precisely, it relates to a control device comprising a control key mounted pivoting on a support, at least one contactor arranged facing a region of the key offset relative to its axis of articulation, and an elongate tie bar, the opposite ends of which co-operate respectively with one contactor and with the said region of the corresponding key. It can be used especially but not exclusively to drive a scrolling menu which allows appliances in a motor vehicle to be controlled.  
         BACKGROUND OF THE INVENTION  
         [0003]    Control devices of this type are already known. They have a key mounted so as to rock on an intermediate plate arranged between the front face of the casing and a printed circuit board. The rocker key acts on one or more tie bars guided in the intermediate plate. Each of these tie bars actuates one contact of a push button mounted on the printed circuit board.  
           [0004]    This device has a number of disadvantages. The number of parts is significant and assembly is time-consuming and intricate.  
           [0005]    Embodiments of the present invention may at least partially remedy these disadvantages.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention proposes a control device which has a reduced number of parts and can be assembled rapidly and easily.  
           [0007]    To this end, the tie bar forms part of a transmitter formed in one piece and furthermore comprising a supporting structure arranged facing the key and mounted in a fixed manner with respect to the contactor, the tie bar being connected to the supporting structure by at least one flexible arm, which allows it to be displaced substantially parallel to the structure so as to transmit to the contactor a pressure exerted on the key.  
           [0008]    The transmitter thus constitutes a piece formed in a single unit which includes one or more tie bars and the means for guiding these tie bars. It can be fitted very easily, simply by placing it on a printed circuit board having one or more contactors, for example.  
           [0009]    The supporting structure of the transmitter preferably serves as a support and a pivot for the control key.  
           [0010]    By virtue of this characteristic, the intermediate plate which, in the prior art, served as a pivot or hinge for the control key, can be dispensed with. The number of parts is thus reduced even further.  
           [0011]    The key preferably has a flared seat which receives part of the supporting structure, which forms a pivot for the key.  
           [0012]    The control device advantageously comprises a casing having a front face comprising a flared seat, which receives an articulation surface of the key. This front face has grooves and the supporting structure has sliding surfaces, which are accommodated in the said grooves.  
           [0013]    According to a particular embodiment, the supporting structure is in the form of a T formed by an upright and a transverse beam. The supporting structure can have a stepped part at each of its ends, each stepped portion comprising a lower step, which forms a pivot for the key, and an upper step. The upper steps of the stepped portions advantageously form sliding surfaces which engage in the grooves in the front of the casing.  
           [0014]    In one embodiment, the tie bar is connected to the supporting structure by two flexible arms, defining a deformable parallelogram. In another embodiment, the tie bar is connected to the supporting structure by a single flexible arm, one end of the tie bar cooperating with the contactor by nesting with it.  
           [0015]    The transmitter is advantageously made from a transparent material. This arrangement makes it easier to illuminate the key by means of a light source, allowing it to be identified easily in the dark.  
           [0016]    Finally, the invention relates to a transmitter suitable for forming part of a control device as defined above, comprising a supporting structure and at least one elongate tie bar connected to the supporting structure by at least one flexible arm. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    Other characteristics and advantages of the invention will become further apparent in reading the following description of two exemplary embodiments given by way of illustration with reference to the attached figures, in which:  
         [0018]    [0018]FIG. 1 is an exploded view in perspective of a control device in accordance with the present invention;  
         [0019]    [0019]FIG. 2 is a view in elevation of the supporting structure of the transmitter of the control device shown in FIG. 1;  
         [0020]    [0020]FIG. 3 is a detail view on an enlarged scale of the articulation of the key on the supporting structure of the control device shown in FIG. 1;  
         [0021]    [0021]FIG. 4 is a view in section of the control device in FIGS.  1  to  3  shown in the rest position;  
         [0022]    [0022]FIG. 5 is a view similar to FIG. 4, the key being shown in the tilted position;  
         [0023]    [0023]FIG. 6 is a schematic view in partial section of a variant embodiment of the invention having a hinged key. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0024]    The control device in accordance with the invention and shown in exploded view in FIG. 1 has a printed circuit board  2 , on which two contactors  4  are fixed via a plate  6 , in which an aperture  8  is formed halfway between the contactors  4 . In this case, the contactors are push buttons. As a variant, they can be replaced by a bubble-switch panel. The printed circuit board  2  is housed within a casing comprising a front face  10  and a rear cover  12 .  
         [0025]    The device has a transmitter designated overall by the reference  16 . The transmitter has a supporting structure  18  and two elongate tie bars  20  and  22  respectively aligned with the contactors  4 . In the exemplary embodiment shown (see FIG. 2), the supporting structure is T-shaped, consisting of a beam  24  which forms the stem of the T and of a second beam  26 , perpendicular to the beam  24 , which forms the crossbar of the T. A stepped portion  32  facing away from beam  24  is formed at each end of beam  26 . This portion has a lower step  31  and an upper step  33 .  
         [0026]    The tie bars  20  and  22  are connected to the supporting structure  18  by flexible arms. In the example described, each of the tie bars  20  and  22  is connected by a single arm  28  to the beam  24  and by a double arm  30  to the two ends of beam  26 .  
         [0027]    Finally, the control device comprises a key  36 . In the example described, the key  36  is of the rocking type. It is supported in its central portion on the two lower steps  31  of the stepped portions  32  formed at each end of the horizontal bar  26  of the supporting structure  18 .  
         [0028]    The transmitter  16  is made of a transparent plastic material, allowing the key to be illuminated by a light source such as a diode. It can thus be identified easily in the dark.  
         [0029]    The way in which the key  36  is articulated on the supporting structure  18 , which forms a support and a pivot for the key  36 , has been shown in greater detail in FIG. 3. The key  36  has a flared seat  38  in the form of a V. A bearing  40  in the form of a portion of a cylinder of revolution is formed at the bottom of the V-shaped seat  38 . The cylindrical surface  40  rests on the lower step  31  of the stepped portion  32 .  
         [0030]    In the same way, the front face  10  of the casing has a flared seat  42 , which receives a cylindrical articulation surface  44  of the key  36  belonging to the same cylinder of revolution as the surface  40   
         [0031]    The two upper steps  33  of the stepped portions  32  form sliding surfaces which penetrate into corresponding grooves  46  of appropriate shape formed in the front face  10  of the casing.  
         [0032]    [0032]FIG. 4 shows a sectional view of the control device according to the invention in the rest position. The device can be assembled simply by placing one part upon another. The transmitter  16  is simply placed on the printed circuit board  2 , the free end of the beam  24  coming to rest in the aperture  8  provided in the plate  6  placed on the printed circuit board  2 . In this position of the transmitter  16 , the tie bars  20  and  22  each rest on a contactor  4  provided on the printed circuit board. The key  36  is then placed on the transmitter in such a way that the flared seats  38  cover the lower steps  31  of the two stepped portions  32 , the width of the key being such that it can protrude between the two upper steps  33  of this same portion. The front face  10  of the casing is then placed on top of the key  36 . The cylindrical articulation surfaces  44  of the key come to rest in the flared seats  42  formed in the rear face of the front face  10  of the casing. The key is thus fixed between the supporting structure  18  and the front face  10  of the casing. However, it can nevertheless pivot on the end of the supporting structure thanks to the presence of the cylindrical surfaces  40  and  44 . The axis of the cylindrical surfaces  40  and  44 , which is perpendicular to the plane of the figure, forms an axis of rotation for the key  46 .  
         [0033]    [0033]FIG. 5 shows the position of the control key  36  when pressure, as shown symbolically by the arrow F, is exerted on the latter in its upper end region facing one of the contactors  4 . The key  36  pivots about its axis of rotation as described above. The pressure F exerted on the key  36  is transmitted to the contactors  4  via tie bar  20 . The two flexible arms  28  and  30  allow tie bar  20  to be displaced freely in translation. With the latter and the supporting structure  18 , they form a deformable parallelogram which keeps the tie bar perpendicular to the printed circuit board, allowing it to act axially on the contactor  4 .  
         [0034]    In FIG. 4, a free space will be seen between the periphery of the key  36  and the front face  10  of the casing. In FIG. 5, it will be seen that this space allows the key to pivot through an angle of approximately 5° to 10°, which is sufficient to close the contactor  4 . When the effort F ceases, the key resumes its initial position shown in FIG. 4 under the effect of the restoring force exerted by the return spring of the contactor  4 . In imposing opposite forces on the key  36 , the two contactors  4  thus keep it in its position of equilibrium at rest, as shown in FIG. 4.  
         [0035]    [0035]FIG. 6 shows a sectional view of a variant embodiment of the invention. In this variant, the control key  46  is no longer articulated in the middle on the supporting structure  18  of the transmitter, like the key  36 , but at one of its ends. As a consequence, the device has only one contactor  4  and one tie bar  20 . In the left-hand part of the figure, the sectional plane passes through the area of articulation of the hinged key  46  on the supporting structure, in a manner similar to that shown on an enlarged scale in FIG. 3. In the right-hand part of FIG. 6, the sectional plane passes through the center of the key in the same way as that shown in FIGS. 4 and 5. As described above, when a force F is exerted on the end of the key  46 , this force is transmitted to the contactor  4  via the tie bar  20 . This contactor closes. When the force F diminishes, the key  46  resumes a rest position (not shown) in the same way as the rocker key described above.  
         [0036]    The control device which has just been described makes it possible to actuate contactors, particularly contactors forming part of an electrical circuit printed on a card. It applies particularly to the selection of values from a scrolling menu for the purpose of controlling appliances such as a heating or air-conditioning system for the vehicle. The rocker key shown in FIGS.  1  to  5  makes it possible to scroll through the menu in both directions. When the upper part of the key is pressed, for example, the value on the menu is incremented. Conversely, when the lower part of this key is pressed, the value on the menu is decremented. In contrast, the control device shown in FIG. 6 allows the values on the menu to be scrolled in only one direction. To return to the initial value, it is necessary to run through all the values on the menu.  
         [0037]    As can be observed, this device is particularly simple because it has a very small number of parts, i.e. essentially the transmitter and the control key. The transmitter can be produced at low cost by molding. Moreover, the device is likewise very simple to assemble since the various pieces merely have to be placed one on top of the other. This gives a simple control device which operates reliably and the cost of which is particularly low.  
         [0038]    In the examples illustrated, the tie bar or each tie bar is connected to the supporting structure by two flexible arms in the vicinity of its two ends. As a variant, a single arm can be provided, in particular in the vicinity of the end of the tie bar which faces the key, the opposite end cooperating with the contactor, by nesting with it for example, so as to fix it in a plane perpendicular to the longitudinal direction of the tie bar.  
         [0039]    Throughout the description, reference has been made to keys and rockers used particularly for selecting values from a scrolling menu so as to control various appliances. However, it is clear that these control devices could control other functions not limited to scrolling menus.  
         [0040]    Similarly, the assembly process described above by way of example is intended specifically for the assembly of a single key or a single rocker. When assembling a plurality of keys, however, it is advantageous to reverse the process by turning the front around and mounting the keys, the transmitter and then the printed circuit board on it, in that order.