Abstract:
A timepiece with a movement that includes: a power source; an element for displaying the current time; a chronograph mechanism including a control mobile ( 60 ) including at least one control member for activating the start, stop and reset functions of the chronograph. The control mobile ( 60 ) further includes a driving member having a toothed sector ( 84 ) kinematically connected to the control member. The timepiece further includes a button that can be rotated, the button being rigidly connected by teeth that can be kinematically connected to the toothed sector so that the pivoting of the button activates the start, stop and reset functions of the chronograph.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to the field of mechanical horology. It more particularly concerns a timepiece comprising a movement equipped with:
       a power source,   means for displaying the current time, and   a chronograph mechanism comprising a control mobile including at least one control member to activate the start, stop and reset functions of the chronograph.       
 
       BACKGROUND OF THE INVENTION 
       [0005]    Chronograph mechanisms are varied and are well known by those skilled in the art. There are two main types, depending on whether the control mobile is a column wheel or a cam. One can in particular refer to the work “Théorie de l&#39;horlogerie” by Reymondin et al, Fédération des Ecoles Techniques, 1998, ISBN 2-940025-10-X, pages 225 to 252, to find details on these mechanisms. 
         [0006]    Conventionally, the functions of the chronograph mechanism are activated using two push-pieces, acting on the control mobile, at a driving member. In chronographs with column wheels, the driving member is a toothed plate. In a cam chronograph, there are two shuttles that make up the cam. The shuttles form both the control member and the driving member. Indeed, one of the push-pieces acts on one of the shuttles so that its movement activates the start and stop functions, and the other of the push-pieces acts on the other one of the shuttles so that its movement activates the reset function. 
         [0007]    Also known are single push-piece chronographs, in which all of the functions are performed, as the name indicates, by a single push-piece. The latter part acts in translation on a column wheel, the control member of which is adapted to control all of the functions. 
         [0008]    Elegantly, this push-piece is generally housed in a control arbor and protrudes from the crown situated at the end of the arbor. The latter performs, conventionally, the setting and winding functions of the movement, independently of the chronograph. The winding is done in position 0 of the control arbor, i.e. when the latter is in its proximal position relative to the movement, and the setting is done in position 1 of the control arbor, i.e. in a more remote position of the arbor relative to the movement. 
         [0009]    It can be noted that in both types of chronograph, bulky levers with sometimes complex forms are inserted between the push-pieces and the driving member of the control member. 
         [0010]    The present invention aims to propose a particularly original alternative to activate the functions of a chronograph mechanism and avoiding the aforementioned drawbacks. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0011]    More precisely, the invention concerns a timepiece as defined in the first paragraph above, characterized in that the control mobile also comprises a driving member including a toothed sector kinematically connected to the control member. The timepiece also comprises a button capable of being driven in rotation, this button being integral with a toothing capable of being kinematically connected to the toothed sector, such that the pivoting of said button activates the start, stop and reset functions of the chronograph. 
         [0012]    It can be noted that, advantageously, the proposed construction makes it possible to eliminate the levers between the control arbor and the driving member. In fact, they can be easily adapted to an existing chronograph mechanism. 
         [0013]    Other advantageous features are defined in the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The present invention is described hereinafter, in reference to the appended drawing, in which: 
           [0015]      FIG. 1  is a top view of one preferred embodiment of the invention, 
           [0016]      FIGS. 2 ,  3  and  4  are top views and  FIG. 5  is a cross-sectional view of details of the mechanism of  FIG. 1 , 
           [0017]      FIGS. 6 ,  7  and  8  illustrate the mechanism in the positions corresponding to the start, stop and reset functions of the chronograph, and 
           [0018]      FIGS. 9 and 10  show two other embodiments according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]      FIG. 1  shows the main elements of a chronograph mechanism according to one preferred embodiment of the invention, the elements being mounted on a frame. This mechanism can be integrated into or mounted modularly on a basic movement which, for the sake of clarity, is not shown. Naturally, this movement comprises a power source to drive a going train and to display the current time using display members. A control arbor  8 , visible in  FIG. 2 , also called winding stem, is provided conventionally to be able to occupy a first position in which it is arranged to wind the power source, and a second position in which it is arranged to act on the display means. These two functions are well known by those skilled in the art and can be done by a system including a winding pinion, a castle-wheel and a pull-out piece. 
         [0020]    Like a conventional cam chronograph mechanism,  10  shows an oscillating pinion, driven continuously by a second wheel of the movement. This pinion  10  is mounted on a lever  12  ending with a first feeler-spindle  14 . A spring member  16  exerts a force on the lever  12  tending to bring the pinion  10  into contact with a chronograph wheel  18 , designed to turn at a rate of one revolution per minute, when the pinion  10  is coupled. 
         [0021]    Typically, the wheel  18  is provided with  60  teeth, so as to provide precise coupling to the second. The chronograph wheel  18  is designed to support a display member for the second of the measured time. A heart-piece  20  is mounted integral on the axis of the wheel  18 . Moreover, an elastic finger  22  is also arranged on the wheel  18 , to drive once per revolution, an intermediate train  24 , engaged with a minute counter wheel  26 . The counter wheel  26  is designed to support a display member of the minute of the measured time. A heart-piece  28  is mounted integral on the axis of the wheel  26 . A jumper spring  30  ensures the positioning of the wheel  26 . 
         [0022]    A brake-lever  32  is mounted pivoting on the frame. It includes a brake  34  designed to cooperate with the chronograph wheel  18  to block its rotation, and a second feeler-spindle  36  designed to control the positioning of the brake-lever  32 , as will be understood later. A spring  35  is arranged so as to exert a force tending to press the brake  34  against the chronograph wheel  18 . 
         [0023]    A double-hammer  38  is provided so as to cooperate with the heart-pieces  20  and  28 , to reset the second and minute display members. The double-hammer  38  is provided with a lever  40  including a third feeler-spindle  42 , designed to control the position of the double-hammer  38 . A yoke  44  is pivotably mounted on the lever. On either side of the pivot point, the yoke  44  is provided with first  48  and second  50  support surfaces, respectively, to cooperate with the heart-pieces. Two pins  52  arranged on the lever  40  are provided to limit the pivoting of the yoke  44 . A spring  54  exerts a force on the yoke tending to bring the support surfaces  48  and  50  against their respective heart-piece. 
         [0024]    A control mobile  60  is arranged to cooperate with the different feeler-spindles and thus to position the above elements so as to activate the start, stop and reset functions of the chronograph mechanism. According to the embodiment chosen as illustration, the control mobile comprises a control member made up of a cam pivoting around an axis AA. One can, for more clarity, refer to  FIGS. 2 ,  3  and  4 , which more particularly show the elements of the cam. 
         [0025]    The cam includes a first shuttle  62  ( FIG. 2 ), called upper. It has an active zone  64  designed to cooperate with the third feeler-spindle  42  of the double-hammer  38 . Depending on the position of the cam, the active zone  64  is arranged so as to oppose or not oppose the force exerted by the spring  54 . Respectively, the support surfaces do or do not cooperate with the heart-pieces of the wheels  18  and  26 . 
         [0026]    The cam includes a second shuttle  66  ( FIG. 3 ), called intermediate, integral in rotation with the first. It has an active zone  78  designed to cooperate with the first feeler-spindle  14  of the yoke  12 . Depending on the position of the cam, the active zone  78  is arranged so as to oppose or not oppose the force exerted by the spring member  16 . Respectively, the pinion  10  is not coupled or is coupled with the chronograph wheel  18 . The shuttle  66  also includes a protruding element, such as a pin  80 , the role of which will appear later. 
         [0027]    The cam also includes a third shuttle  76  ( FIG. 4 ), called lower. The shuttle  76  has two hollows  70   a,  separated by a tooth  70   b,  with which a jumper  72  cooperates, so as to define the two stable positions of the cam corresponding to the start and stop functions of the chronograph. Moreover, one of the hollows, that defining the stop function, extends beyond the level defined by the tooth  70   b,  by an inclined plane  70   c  with which the jumper  72  cooperates to position the cam for the reset function of the chronograph. Lastly, the shuttle  76  has a housing  74  positioned and dimensioned such that the pin  80  is positioned there, without play in the direction of rotation of the cam. The shuttle  76  also has an active zone  68  designed to cooperate with the second feeler-spindle  36  of the brake-lever  32 . Depending on the position of the cam, the active zone  68  is arranged so as to oppose or not oppose the force exerted by the spring  35 . Respectively, the brake  34  does not cooperate or cooperates with the chronograph wheel  18 . 
         [0028]    An additional spring  82  is positioned so as to act on one of the shuttles, preferably on the third shuttle  76 , when the reset function is activated, so that it is harder for the user to activate. 
         [0029]    According to one important aspect of the invention, the shuttle  76  extends in a toothed sector  84 , concentric to the axis AA. One therefore understands that by acting on the toothed sector  84 , one will drive the pivoting of the lower cam and, with it, via the cooperation between the pin  80  and the walls of the housing  74 , the pivoting of the shuttles  66  and  62 . One will note that the pin  80  and the housing  74  could be reversed, the pin  80  being on the shuttle  76  and the housing being on the shuttle  66 . 
         [0030]    To act on the toothed sector, the timepiece according to the invention proposes using the control stem  8  of the movement. Other than the winding pinion and the castle-wheel, the stem  8  supports an additional pinion  86 , integral in rotation and designed to mesh with the toothed sector  84 , in a predetermined position of the stem  8 . As shown in  FIG. 5 , the pinion  86  and the toothed sector  84  mesh at 90°. One therefore sees that this construction makes it possible to avoid any arm and intermediate lever between the crown of the winding stem, which serves as actuating member for the chronograph, and the control mobile. There is indeed a direct transmission of the power, by meshing between the pinion  86  and the sector  84 . The operation is particularly flexible and precise relative to a mechanism comprising arms and levers between the push-pieces and the control mobile. 
         [0031]    To allow comfortable operation of the activation of the chronograph functions, the movement of the toothed sector must be fairly quick, relative to the rotation of the crown. Indeed, for example, the starting of the chronograph must be done after a limited rotation of the crown and not after a complete revolution. In this aim, the diameter of the pinion  86  is relatively significant, typically in the vicinity of 5 mm. Moreover, according to the construction illustrated in the drawing, the toothed sector  84  can be situated on the periphery of the movement. The pinion  86  is then relatively close to the crown, which can make it difficult to mount in the case. To offset this problem, the stem is preferably jointed, essentially at the pinion, between the latter part and the crown. The portion of the stem supporting the pinion  86  can thus be easily assembled in the movement, while the other portion, designed to support the crown, can be mounted after interlocking, through the outside. 
         [0032]    The position of the castle-wheel and the winding pinion can advantageously be adapted such that, in its proximal position, the stem makes it possible to activate the chronograph functions. There is therefore no need to exert any prior traction on the stem to start the chronograph. When the control stem is pulled into a second position, the power source can be wound and, in a third distal position, the setting can be done. 
         [0033]    We will now describe the activation of the different functions of the chronograph, in reference to  FIGS. 6 ,  7  and  8 . 
         [0034]    Idle ( FIG. 6 ), the toothed sector  84  is essentially symmetrical relative to the axis of the control stem. The cam is kept in that position by the jumper  72 , which cooperates with a first hollow  70   a.  The first feeler-spindle  14  of the lever  12  bears on the active zone  78  of the shuttle  66 . The pinion  10  is uncoupled from the chronograph wheel  18 . At the second feeler-spindle  36  of the brake-lever  32 , the active zone  68  of the third shuttle  76  does not oppose the spring  35  and the brake  34  cooperates with the wheel  18  to block it. The third feeler-spindle  42  of the double-hammer cooperates with the active zone  64  of the first shuttle  62  to oppose the spring  54 . The hammer is raised and the support surfaces do not cooperate with the heart-pieces  20  and  28 . 
         [0035]    To activate the start function of the chronograph, the crown is pivoted by the wearer in the counterclockwise direction, so as to drive the rotation of the shuttle  76  in the clockwise direction, in reference to  FIG. 7 . The rotation of the shuttle  76  drives the simultaneous pivoting of the shuttles  66  and  62 . The jumper  72  goes into the other hollow  70   a  and thus keeps the cam in that position. The first feeler-spindle  14  of the lever  12  no longer bears on the active zone  78  of the shuttle  66 , which therefore no longer opposes the spring  16 . The pinion  10  is coupled on the chronograph wheel  18 . The second feeler-spindle  36  of the brake-lever  32  bears on the active zone  68  of the third shuttle  76 , which opposes the spring  35 . The brake  34  no longer cooperates with the wheel  18 . The hammer is still raised and the support surfaces do not cooperate with the heart-pieces  20  and  28 . 
         [0036]    Clockwise pivoting of the crown by the wearer causes the counterclockwise rotation of the shuttle  76 , in reference to  FIG. 6 . The shuttles  66  and  62  also pivot and the jumper  72  goes back into the first hollow  70   a.  One is then in the idle position previously described, the chronograph is stopped. The wearer can restart and stop the chronograph as desired, without resetting. 
         [0037]    To activate the reset, the wearer must, in reference to the idle position, by way of which he must necessarily pass, pivot the crown clockwise, driving the counterclockwise rotation of the shuttle  76 , in reference to  FIG. 8 . The shuttles  66  and  62  also pivot, stressing the additional spring  82 , and the jumper  72  goes up on the inclined flank  70   c.  The first feeler-spindle  14  of the lever  12  is still bearing on the active zone  78  of the shuttle  66 . The pinion  10  is uncoupled from the chronograph wheel  18 . The second feeler-spindle  36  of the brake-lever  32  bears on the active zone  68  of the third shuttle  76 , which opposes the spring  35 . The brake  34  does not cooperate with the wheel  18 . The third feeler-spindle  42  of the double-hammer no longer cooperates with the active zone  64  of the first shuttle  62 . Under the effect of the spring  54 , the hammer falls and the support surfaces press the heart-pieces  20  and  28 , to reset the display members. When the user releases the crown, the jumper  72  returns the mechanism to its idle position, through action on the inclined flank  70   c.    
         [0038]    It is therefore the jumper that positions the cam such that the functions can be performed correctly. However, the user could pivot the crown too much, which could cause the shuttles to force on the feeler-spindles. To avoid this, it is possible to have banking elements on the frame, on either side of the shuttle  76 . 
         [0039]    Thus is proposed a chronograph mechanism making it possible to activate the different functions particularly originally, while eliminating any lever between the control stem and the driving member of the control member. 
         [0040]      FIGS. 9 and 10  propose two other embodiments, also making it possible to actuate the different functions of the chronograph according to a principle similar to that proposed above. 
         [0041]    In  FIG. 9 , we see the toothed sector  84  ending the third shuttle  76 . A ring  90  dimensioned so as to essentially surround the movement is arranged on the casing-ring. More particularly, the inner diameter of the ring  90  is sufficient for the movement to be able to be positioned there, while its outer diameter allows that ring  90  to be masked by the casing ring or inside the watch case. The ring  90  is placed on the casing ring and is guided in rotation, possibly by stones. The ring  90  is at least partially toothed and comprises a first  90   a  and second  90   b  toothing, on its inner periphery and on its outer periphery, respectively. The toothings can be directly notched in the ring, on the entire periphery or not, or, as in the example shown in  FIG. 9 , be made by attached pieces, making it possible to arrange the toothings only in the required zones. Such an arrangement can be interesting in terms of bulk. 
         [0042]    To actuate the chronograph functions, a button  92  is mounted in rotation in the case, so as to be accessible from the outside by the wearer of the watch. In the illustrated example, but non-limitingly, the button  92  can pivot along an axis perpendicular to the plane of the movement. In other words, the button defines a plane essentially parallel to that of the movement. The button  92  is integral in rotation with a toothing, typically assuming the form of a pinion  94  arranged coaxially thereto. This pinion  94  meshes with the ring  90 , preferably by the second toothing  90   b  situated at its outer periphery. The toothed sector  84  is engaged with the first toothing  90   a  situated at the inner periphery of the ring. 
         [0043]    Thus, by pivoting the button  92 , the user can actuate the different functions of the chronograph. One will note that the button  92  can also be mounted pivoting along an axis parallel to that of the movement, the pinion  94  meshing perpendicularly with the ring. 
         [0044]    In  FIG. 10 , there is also a toothed sector  84  ending the third shuttle  76 . A rack  96  is mounted mobile in translation inside the case or the movement, being guided by at least one oblong opening, inside which a fixed element cooperates, such as a screw, for example, fixed on a support of the movement or on the case of the movement. A person skilled in the art can use any other means at his disposal to mount the rack. A button  92  is mounted in rotation in the case, in order to be accessible from the outside. In one advantageous embodiment, the button is mounted on the upper portion of the case, on the dial side, possibly in a corner of said case, in the event of a square case with a round dial. As in the preceding embodiment, the button  92  can pivot along an axis perpendicular to the plane of the movement and is integral with a pinion  94 , which is coaxial thereto. The rack  96  meshes on one hand with the pinion  94  and on the other hand with the toothed sector  84 . A person skilled in the art will easily be able to adapt the different levels of these elements such that the rack  96  can transmit a rotation of the button  92  to the driving member of the chronograph mechanism. In particular, the toothed sector  84  normally being situated on the side of the back of the movement, if the button  92  is situated on the dial side, the pinion  94  can be connected to the button  92  by an arbor that passes through the movement. Thus, by pivoting the button, the user can actuate the different functions of the chronograph. 
         [0045]    The embodiments of  FIGS. 9 and 10  have the same advantages as above, with the additional advantage of releasing the control stem for a third function, in particular for correcting a date or a GMT, for example. In these embodiments, the control stem  98  no longer has a functional connection with the chronograph mechanism. Moreover, the builder can arrange the control member of the chronograph particularly flexibly, in reference to the button. 
         [0046]    The description above was provided as a non-limiting example of the invention. Thus, the control member could also be a column wheel, the toothed sector of the driving member then assuming the form of a wheel. The activation of the different functions will then have to be adapted. Thus, the crown would still have to turn in the same direction to go from one function to the other, the chronograph only being able to function according to the start/stop/reset sequence. Certain details of the embodiments could obviously be adapted by one skilled in the art, in particular at the connection between the shuttles, or in the limitation of the travel of the cam.