Abstract:
A timepiece includes: a frame ( 10 ) defining a housing designed to accommodate a timepiece movement; and a dial ( 14 ) positioned on the frame and defining a plane, the dial including at least one opening ( 16 ) whose dimensions are such as to allow at least one index ( 18 ) mounted rotationally on the frame to be seen.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to the horology field. It more particularly concerns a timepiece comprising: 
         [0002]    a frame defining a housing designed to receive a timepiece movement, and 
         [0003]    a dial positioned on the frame and defining a plane, the dial including at least one opening, dimensioned so as to leave at least one index mounted rotationally on the frame to be visible. 
       BACKGROUND OF THE INVENTION 
       [0004]    Document CH684814 discloses a timepiece as defined above, in which the rotary indexes are mounted pivoting along axes situated parallel in reference to the plane defined by the dial. According to this document, the indexes are of the prismatic type and have several faces, designed either to be displayed or hidden. When a face of the prism is displayed, it is completely visible in the opening of the dial. This device in particular has the drawback of requiring a relatively significant thickness, such that the prism can be housed and can pivot. Moreover, during pivoting of the prisms, the openings of the dial can be partially gaping, depending on the shape of the prisms, which can be considered not very esthetically pleasing. 
         [0005]    The present invention aims to propose a timepiece whereof the dial makes it possible to present several visual appearances, which a user can show as desired, while also resolving the aforementioned drawbacks. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0006]    More precisely, the invention concerns a timepiece as defined in the first paragraph above, characterized in that the index is mounted rotating along an axis essentially perpendicular to the plane of the dial and having a display surface situated on the dial side, oriented along a plane essentially parallel to that of the dial. A fitting is positioned so as to partially cover the display surface, dividing said display surface in a first hidden portion and a second visible portion. The timepiece also comprises a control organ capable of being actuated by a user, associated with kinematic transmission means connecting the control organ and the index, such that an action on the control organ drives the rotation of the rotary index, so that the visible portion becomes hidden and at least the main part of the hidden portion becomes visible. 
         [0007]    Other advantageous features of the invention are defined in the dependent claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    Other features of the present invention will appear more clearly upon reading the description that follows, done in reference to the appended drawing, in which: 
           [0009]      FIG. 1  is a top view of a timepiece according to a first embodiment, 
           [0010]      FIGS. 2 ,  3  and  4  are cross-sectional views, along different axes, of the timepiece of  FIG. 1 , 
           [0011]      FIGS. 5 and 6  are top and cross-sectional views, respectively, of a timepiece according to a second embodiment, and 
           [0012]      FIG. 7  is a cross-sectional view of a timepiece according to a third embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0013]      FIG. 1  diagrammatically shows a timepiece according to the invention, provided with a frame  10  defining a housing designed to receive a timepiece movement  12 , positioned by one rim  13 , visible in the figures in cross-section. The movement is fastened to the frame  10  conventionally, for example using a system of case screws, not shown. 
         [0014]    Commonly, a dial  14  defining a plane is positioned on the frame  10  so that the movement  12  is not visible and to provide guide marks making it possible to display time information in cooperation with mobile elements driven by the movement, such as hands. In conventional dials, it is usual to have twelve indexes, regularly distributed on the periphery of the dial, in order to allow the reading of the time in reference to the position of the mobile elements. 
         [0015]    According to the invention, the dial  14  includes twelve openings  16 , preferably circular in shape, centered on the spokes on which the indexes are usually placed. The openings  16  are dimensioned so as to allow at least one index  18 , provided with a display surface  20 , mounted rotationally on the frame as will be described later, to be visible. As visible in  FIG. 2 , in this embodiment, the openings  16  allow the passage of the entire display surface  20  of the index. 
         [0016]    In reference to  FIG. 2  showing a cross-section passing through the center of the display surface  20  of an index, these indexes  18  being rotationally mounted along an axis essentially perpendicular to the plane of the dial. Their display surface  20  is situated on the dial side and is oriented along a plane essentially parallel to that of the dial  14 . 
         [0017]    We will now describe the pivoting of the indexes  18 . Each index includes an axis  22  provided, integral with a first of its ends, with a plate  24  whereof the surface situated on the side opposite the axis forms the display surface  20 . The axis  22  is again provided, integral at its second end, with a pinion  26 . The latter part is essentially parallel to the plate  24  and these two elements are perpendicular to the axis  22 . This axis  22  is situated in a bore  28  formed in the thickness of the frame  10 , so as to be able to turn freely therein. In this embodiment, the axis  22  is dimensioned such that the display surface  20  is flush with the upper surface of the dial  14 , visible by the user. The plate  24 , on one hand, and the pinion  26 , on the other, sandwich the frame  10 , thereby ensuring the positioning of the display surface. 
         [0018]    According to the invention, a fitting  30  is positioned so as to partially cover the display surface  20  of the indexes  18 . This fitting  30  divides the display surface  20  into a first hidden portion  20   a  and a second visible portion  20   b . In the embodiment of  FIG. 2 , the fitting  30  is obtained by a rim presented by the watch case  32 , typically its middle. The rim passes essentially through the center of the display surface  20 , the two portions  20   a  and  20   b  being essentially equal. It can be made in a single piece or attached on the middle. 
         [0019]    The aim of the invention is to make it possible to show, as desired, one or the other of the portions  20   a  and  20   b , the other being hidden. The indexes can therefore evolve between a first position, in which the portion  20   b  of their display surface is visible, the other  20   a  being hidden, and a second position, in which the portion  20   b  visible in the first position is hidden, and the portion  20   a  hidden in the first position is essentially visible. 
         [0020]    One will note that, in the second position, the portion hidden in the first position is only essentially visible because, for the timepiece to keep a normal appearance, the fitting  30  is circular in shape, like a normal bezel of a round watch case. Because of this, there is a zone of the display surface  20 , essentially situated on a diameter of the surface separating the two portions, that remains hidden in the two positions the indexes can assume  18 . 
         [0021]    This arrangement can allow particularly interesting design play, in particular by showing numerical indexes or making them disappear in order to have a more harmonious design on the dial, without the indexes disrupting it. 
         [0022]    To drive the rotation of these indexes  18 , the timepiece proposes a control organ, visible in  FIG. 3 , accessible from the outside of the timepiece by the wearer of the watch, and kinematically connected to the indexes by kinematic transmission means. One will note that  FIG. 3  is a cross-section along an axis passing through the control organ. According to the embodiment illustrated in the figures, the control organ assumes the form of a button  34  capable of being driven in rotation, like a winding stem crown. 
         [0023]    In a more detailed manner, the button  34  is mounted on a stem  36  parallel to the plane of the dial  14  and passing through the watch case. The end of the stem  36  situated inside the case supports a toothed wheel  38 , meshing with a first toothing  40   a  of a crown  40 . The latter part is positioned around the movement  12 , parallel to the frame  10  and is capable of pivoting around the movement  12 . The crown  40  is guided in rotation and is positioned owing to a groove  42  included by the frame  10 , formed on an extension  10   a  of the frame, extending toward the bottom of the movement. 
         [0024]    Preferably, the first toothing  40   a  of the crown  40  is formed horizontally in reference to  FIG. 2 , on a first rim  40   b  of the crown  40 . The meshing conditions of the first toothing  40   a  with the toothed wheel  38  are thus optimal. One will note that a perpendicular meshing could also be used. 
         [0025]    The crown  40  also includes a second rim  40   c , situated on the side of the crown  40  of smallest radius. This second rim  40   c  has a second toothing  40   d , positioned vertically, in reference to  FIG. 3 . This second toothing  40   d  is engaged with the pinions  26  of the indexes. 
         [0026]    The crown  40  therefore has first  40   a  and second  40   d  toothings, situated on either side of a bottom  40   e , which can advantageously participate in the positioning and guiding of the indexes  18 . Thus, the bottom  40   e  of the crown can serve as a support for the axis  22  of the indexes, as one can see in  FIG. 2 . 
         [0027]    To optimize the operation of a timepiece according to the invention, it is advantageous to control or even limit the rotation of the indexes  18 , so that the portions  20   a  and  20   b  defined by the fitting  30  indeed pass alternatingly from the hidden position to the visible position, avoiding finding themselves in intermediate positions. The rotation of the indexes  18  being controlled by the control organ via the rotation of the crown  40 , it is advantageous to control the rotation of all of the indexes  18  by acting on the rotation of the crown  40 , which is easier than acting on the rotation of the button  34 . 
         [0028]    To do this, the crown therefore includes organs limiting the rotation of the indexes. In this aim, the rotation of the crown  40  is controlled, as shown by  FIG. 4 , owing to an element  44 , such as a pin, positioned protruding on the frame  10  and cooperating with a recess  46  formed in the bottom  40   e  of the crown  40 , the recess  46  having a circular arc shape, concentric to the crown  40 . The length of the recess  46  is defined so as to have a desired rotation of the indexes  18 , the element  44  only being able to move inside the recess  46 . Preferably, as in the illustrated embodiment, the rotation of the indexes  18  is in the vicinity of 180°. The person skilled in the art can also provide for forming a notch, allowing the user to feel when the controlled positions of the indexes are reached. For example, he can mount the element  44  on a spring system, making it possible to realize the notch while cooperating with a relief of the recess. The element can then be a spring loaded ball, mounted mobile at the end of a tube. In that case, it is possible to allow the user to turn the button  34  without limitation, in one direction or the other, the user simply feeling the notches when the indexes are in the desired position. One will note that, for safety, a friction or torque limiting system can be inserted between the button  34  and the crown  40  such that, when the crown is immobilized in rotation, breakage is avoided if the user forces the button. 
         [0029]    Thus, in operation, the indexes  18  are capable of evolving between 
         [0030]    a first position, in which one portion  20   b  of their display surface is visible, the other  20   a  being hidden, and 
         [0031]    a second position, in which the portion  20   b  visible in the first position is hidden, and the portion  20   a  hidden in the first position is essentially visible. 
         [0032]    When the indexes  18  are in their first position, the wearer can actuate the button  34  by pivoting it in a first direction. The toothed wheel  38  will then drive the rotation of the crown  40 , through the first toothing  40   a . The crown  40  then drives the rotation of the indexes  18 , by meshing of the second toothing  40   d  with the pinion  26  of each index  18 . 
         [0033]    When the protruding element  44  has reached the end of the recess  46 , the indexes  18  have pivoted so as to be found in the second aforementioned position. The rotation of the crown  40  is thus stopped. Reverse actuation on the button  34  makes it possible to bring the indexes  18  back from their second to their first position. 
         [0034]    Alternatively, with a notch positioning system, the indexes have reached their second position when the mobile element assumes its position in the relief of the recess. The return of the indexes to their first position can be done either by reverse rotation of the button  34 , or by continuing the rotation of the button in the same direction and bringing the mobile element into a following relief included in the recess. 
         [0035]      FIGS. 5 and 6  propose a second embodiment, differing from the first by the realization of the fitting  30 . The openings  16  formed in the dial  14  are dimensioned so as to leave each index  18  visible, but only partially, such that the dial  14  itself defines the fitting  30 . This arrangement has the advantage of allowing more latitude in terms of the shape of the openings  16  and fittings  30 , without harming the overall esthetics of the piece. Thus, the openings  18  can be perfectly semi-circular, dividing the display zone  20  into two equal half-circles. This embodiment can also allow one to consider having the fitting  30  cover only one sector of 360/N degrees, the display surface  20  being divided into N equal portions, successively appearing or not appearing on the dial. In this case, the display surfaces can even not be circular and have a regular polygon shape. The marking of the different positions of the crown  40  by notch is then very useful to mark the successive positions assumed by the indexes  18 . In this embodiment, one will note that the display surface  20  is situated at a slightly lower level in reference to the surface of the dial. The latter part can have a shoulder slightly covering the index, in order to participate in its positioning. One will also note that, to optimize the thickness occupied by the indexes, the plate  24  can be positioned, partially or totally, in the thickness of the dial  14 . 
         [0036]      FIG. 7  shows an additional alternative, in which the display surface  20  of the indexes  18  is situated at a slightly higher level relative to the surface of the dial. It is, like in the first embodiment described, elements of the case  32  that make up the fitting  30 . 
         [0037]    The description above was provided as a non-limiting illustration of the invention. Thus, it is of course not necessary to have twelve rotary indexes. There can very well only be one or an indifferent number. Moreover, the illustrations show circular dials, which is indeed advantageous for the realization of the invention. One will note, however, that the second embodiment makes it possible to have a square or rectangular dial or case, in which the ring is placed. 
         [0038]    Moreover, the organ for controlling the rotation of the indexes may not be a button capable of being driven in rotation. The person skilled in the art will know how to arrange other control organs capable of setting the crown in rotation. This rotation can be obtained by a bolt sliding in the edge of the case, the bolt being associated with a toothed sector. A push-piece cooperating with a ratchet or a rack can also be used.