Abstract:
A watch movement, includes a frame ( 10, 11, 20, 22, 24 ), defined by a first and a second parallel plane surface and defining reference planes (A, B), the second plane (B) being located alongside the movement for placing adjacent to the wrist of the wearer, at least one balance wheel ( 30 ), pivoting in bearings fixed in the frame, at least one escape mechanism ( 26, 28 ) providing support for the balance wheel, an energy source ( 12 ), clockwork finishing movements ( 14 ), connecting the energy source to the escape mechanism and motion work ( 42 ).The balance wheel turns about an axis (YY), inclined in relation to the reference planes and intersecting the same, the point of intersection (PA) of the axis (Y) with the first plane (A) being closer to the center of the movement than the point of intersection (PB) of the axis (Y) with the second plane (B).

Description:
TECHNICAL FIELD 
     The present invention relates to watch movements, more particularly of the type comprising a sprung balance. Movements of this type comprise a frame. They are inserted between first and second parallel plane surfaces. The first surface generally serves as support for the dial, while the second is defined by the upper face of the bridges or of the oscillating weight, or the upper face of parts making up a mechanism. This face is generally intended to be adjacent to the wrist of the wearer. 
     BACKGROUND OF THE INVENTION 
     The frame supports wheel assemblies generally arranged such that their axes of rotation are parallel to each other and perpendicular to said plane surfaces. These wheel assemblies, of discoid shape, are more or less superimposed, depending on their position in reference to the frame. One of them, arranged to support time indicator organs, is arranged in the vicinity of the first surface. 
     One also knows movements built in several sections, enveloping the wrist and making it possible to make a domed watch. The curve allowed by such a shape makes it possible to make relatively thin watches which have a particular esthetic. The movement thus realized occupies a relatively significant volume. It is unfortunately difficult to realize a sealed case able to house a movement of this type. Such movements are, for example, described in documents CH 60 360 or EP 1 394 638. 
     One also knows movements provided with a tourbillon whereof the cage supports a balance inclined in relation to the plane of the movement, described, for example, in documents WO 03/017009, WO 2005/043257 and EP 1 564 608. In these movements, and due to the rotation of the cage, the axis of the balance forms the envelope of a cone. Such a solution has the advantage of reducing the sensitivity to positions, but requires a substantial volume. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The primary aims of the present invention are to enable the realization of a movement occupying a limited volume, able to be housed without other in a sealed case and/or to offer optimal operating conditions of the balance. 
     To this end, the movement according to the invention comprises a frame, limited by first and second parallel plane surfaces and defining first and second reference planes, the second plane being on the side of the movement designed to be adjacent to the wrist of the wearer, and which comprises:
         a balance having an arbor pivoting in bearings fixed in said frame,   an escapement allowing to maintain the balance,   an energy source,   a going train wheel assembly generally connecting the energy source to the escapement and ensuring the reduction of the torque applied by the energy source to the first wheel assembly of said going train, and a motion work wheel assembly generally connecting the display means to correction means.       

     According to the invention, the balance oscillates around an axis inclined in relation to the reference planes and intersecting the latter, the point of intersection of the axis with the first plane being closer to the center of the movement than the point of intersection of this axis with the second plane. In this way, the incline of the balance frees up volume in the central part of the movement near the dial, which generally receives the wheel assembly supporting the time indicating organ. 
     The distribution of the components arranged in this part of the watch is difficult to achieve. Thus, by freeing up space, construction security can be increased, without the occupied volume being more significant. 
     Advantageously, the frame comprises an organ on which the balance and the escapement are mounted, which together form a platform escapement. 
     It appears that inclining all of the wheel assemblies of the going train in relation to the reference planes allows a different distribution of the components, which offers in particular new possibilities for esthetic creations. 
     In a piece where the energy source is formed by a barrel, it is also possible to arrange the balance and the barrel inclined in relation both to the reference planes and to each other. 
     When the movement is equipped with an automatic mechanism, comprising an inertial mass passing above the balance, the fact that the balance is inclined, as defined in claim  1 , makes it possible to free up space in order to increase the volume of the sector of the inertial mass, thereby improving the winding conditions, especially for movements with small dimensions. 
     In order to reduce operating deviations as much as possible between the different positions of the watch, while also having a balance with a sufficiently large diameter for its inertial momentum to grant the movement good regulating qualities, the axis of the balance makes an angle between 15° and 30° with the reference planes. 
     Advantageously, in a movement also comprising a winding and setting stem, a plane passing through the axis of the balance and perpendicular to the reference planes makes an angle between 30° and 60° in relation to the axis of said stem. 
     The movement can comprise more than one balance, for example two balances, each of the balances oscillating around an axis inclined in relation to the reference planes and intersecting them, the points of intersection of the axes with the first plane being closer to the center of the movement than the points of intersection of the axes with the second plane. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be better understood upon reading the following description, provided as an example and done in reference to the drawing in which: 
         FIGS. 1 to 4  illustrate all or part of a watch movement according to a first embodiment of the invention; 
         FIGS. 5 to 11  concern a second embodiment; 
         FIGS. 12 and 13  illustrate a movement portion according to a variation of the second embodiment, seen in perspective view and outline sketch, respectively, while  FIGS. 14 and 15  illustrate a watch provided with a movement of this type, seen from two different angles; 
         FIG. 16  refers to another variation of the second embodiment; and 
         FIG. 17  illustrates a variation of the first embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The watch movement illustrated in  FIGS. 1 to 4  comprises in particular and traditionally a plate  10  and a plate bar  11 , partially removed in  FIG. 1  and secured on the plate  10  using screws (not referenced), a barrel  12  forming the energy source, a going train  14 , a regulating organ made up of a platform escapement  16  and a winding and setting mechanism comprising in particular a setting stem  18 , only component visible in these figures. The plate  10  is of a generally discoid shape and defines a central axis XX ( FIG. 3 ). In this movement, the barrel  12  and the components of the going train  14  turn around axes parallel to the axis XX. 
     The platform escapement  16  comprises a base  20  and, secured on the latter using screws (not referenced), a balance-cock  22 , two columns  23  inserted between the base  20  and the cock  22  ( FIG. 1 ), and an escapement bridge  24 . An escape wheel  26  and an anchor  28 , together forming the escapement of the watch, are mounted pivoting between the base  20  and the escapement bridge  24 . This mechanism ensures the maintenance of a sprung balance  30  mounted pivoting between the base  20  and the balance-cock  22 , around an axis YY ( FIG. 3 ), in bearings  31  secured respectively in the base  20  and the balance-cock  22 , only the bearing connected to the cock  22  being visible in the drawing. These bearings are advantageously of the anti-shock type. 
     The plate  10 , the plate bar  11 , the base  20 , the balance-cock  22  and the escapement bridge  24  form the main components of the frame of the movement. The outer surfaces of the plate  10  and of the plate bar  11  define parallel planes A and B ( FIG. 3 ). The outer surface of the plate  10 , defining the plate A, is designed to support a dial, while the plane B is in the part of the movement adjacent to the wrist of the wearer. 
     Typically, the axis YY is inclined by 15° to 30° in relation to one perpendicular to the planes A and B, the incline depending on the characteristics of the movement. The most favorable spatial conditions are obtained when a plane parallel to the plane A and going through the end of the arbor of the balance closest to the felloe is tangent to the outside thereof. In this way, the balance uses the minimum thickness. It goes without saying that other construction parameters can also be used to define this incline. 
     As shown in  FIGS. 1 to 4 , the base  20  has, according to a plane going through the axes XX and YY, a corner section, forming a rectangle triangle. The largest of the sides adjacent to the right angle bears against the plate  10 . The hypotenuse defines a plane which forms a reference surface, the axes of the balance  30 , anchor  28  and escape wheel  26  being perpendicular thereto. This means that the balance  30  and the components  26  and  28  of the escapement turn around axes inclined in relation to the planes A and B of the movement, the incline being equal to the angle formed by the hypotenuse and the long side of the aforementioned triangle. As shown in  FIG. 3 , the orientation of the balance is such that the point of intersection PA of the axis Y with the plane A is closer to the axis XX than the point of intersection PB with the plane B. 
     The assembly of the movement which has just been described begins by placing bearings and feet. Then, the mechanisms and the train are mounted on the plate. In parallel, the components of the platform escapement  16  are assembled and adjusted. The latter is then put into place on the plate, as the last operation. If necessary, the running of the piece can be adjusted again. 
       FIG. 2  shows one advantage which may be drawn from a configuration such as that of the described movement. By placing the balance  30  inclined in relation to the barrel  12 , it is possible to have more space for the latter, or to reduce the thickness of the movement for a same barrel volume. Moreover, because the balance  30  is inclined in relation to the planes A and B, the gaps between the vertical positions and the horizontal positions are reduced. Indeed, when the watch is in horizontal position, meaning that the planes A and B are horizontal, the axis of the balance is inclined. Moreover, when the watch is placed in a vertical position, the axis of the balance is also inclined and not horizontal as in traditional watches. In this way, the instantaneous rates measured are closer to the usual wearing conditions. This is particularly true when the construction is such that a plane going through the axis YY of the balance and perpendicular to the planes A and B makes an angle between 30° and 60° in relation to the axis of the stem  18 . 
     As one can see in  FIG. 3 , a correct connection between the going train  14 , and more particularly its seconds wheel  14   a , with the escapement pinion  26   a  of the wheel  26  is ensured thanks to the fact that the board  14   b  of the wheel  14   a  has a conical toothing. 
     In  FIG. 4 , the movement illustrated in the preceding figures is completed by an automatic winding mechanism more particularly comprising a rotor  32  including a board  32   a  and an inertial mass  32   b . Due to the incline of the balance  30 , the thickness reserved for the inertial mass  32   b  can be substantially increased. In this way, even with a reduced thickness or diameter, it is possible to obtain a winding torque equivalent to those of existing movements. 
       FIGS. 5 to 11  illustrate a watch movement according to a second embodiment. In these figures, the same components bear the same references as those used for the first embodiment. This movement differs from that illustrated in  FIGS. 1 to 4  due to the fact that the going train wheel assemblies  14  as well as the barrel  12  are parallel to the axis YY of the balance  30 . 
     In this embodiment, the plate  10  comprises support surfaces  34  and  36  ( FIG. 5 ) which are not perpendicular to the axis XX, as is generally the case, but rather to the axis YY. Moreover, the holes in which the bearings  38  are arranged ensure the pivoting of the going train wheel assemblies  14  and those serving to house foot screws  40  are also inclined in relation to the axis XX and are parallel to the axis YY ( FIGS. 6 to 10 ). 
     The support surface  36  ensures the positioning of the platform escapement  16 . As one can see more particularly in  FIG. 8 , the columns  23  are driven in the base  20 . The cock  22  is secured on the columns  23  using screws (not referenced). The columns  23  are provided with feet  23   a  protruding from the base  20  from the side of the plate  10  and are engaged in holes  40  thereof, secured using screws. 
     In a variation not shown, the base of the platform escapement  16  could have been removed and the bearing of the balance secured directly in the plate  10 . The balance-cock  22  would then also be secured directly on the plate  10 . 
     As shown by  FIG. 11 , the display is done using wheel assemblies whereof the axis is parallel to the plane A. To this end, the movement supports a minute train  42  comprising a cannon-pinion  42   a , a minute wheel  42   b  and an hour wheel  42   c , the cannon-pinion  42   a  and the hour wheel  42   c  turning around the axis XX. 
     A pinion  44  is mounted pivoting in the plate  10 . It comprises an arbor  44   a  and a conical toothing  44   b . The cannon-pinion  42   a  is frictionally fastened on the arbor  44   a.    
     The going train  14  comprises a wheel  14   c  driven by the barrel  12  and turning at a speed slower than one revolution per hour. It drives the pinion  44   a  which must perform one revolution per hour and which causes the cannon-pinion  42   a  to turn with it. The latter part drives the minute wheel  42   b , which is engaged with the hour wheel  42   c.    
     Thus, thanks to the conical toothing of the pinion  44 , it is possible to realize a movement in which the display is done in planes parallel to the plane A, while having oriented the wheel assemblies of the going train and the time base along axes parallel to each other but inclined in relation to the planes A and B. 
       FIGS. 12 and 13  show part of the wheel assemblies of a movement, variation of the embodiment previously described and bearing hands  46  and  48  designed to display the hours and minutes, respectively. These wheel assemblies are arranged on the frame of the watch, which does not appear in these figures, to avoid overloading the drawing. They are arranged parallel to the axis YY. More precisely, the movement supports a wheel  50  driven by the barrel and performing one revolution in several hours. It meshes with a pinion  51 , mounted pivoting on the frame, and which supports, frictionally mounted, a cannon-pinion  52 , which is provided with a cam  54  of the spiral type. A lever  56 , provided with a toothed sector  56   a  at one end and a finger  56   b  at the other end, rests by its finger  56   b  against the cam  54 , under the effect of a spring diagrammatically illustrated by an arrow. A pinion  58  is engaged with the toothed sector  56   a . It supports the hand  48 . The cam  54  turns with the cannon-pinion  52  and causes the angular movement of the lever  56 , which causes the hand  48  to turn, which moves opposite a graduated scale  59  supported by a dial  60  ( FIGS. 14 and 15 ). The gear ratio between the wheel  50  and the pinion  52  is chosen such that the latter part performs one revolution in one hour. As a result, the hand  48  sweeps the graduated scale  59  in one hour. 
     Once the cam  54  has performed one revolution, the lever  56  falls back and the hand  48  jumps abruptly while crossing the graduated scale  59  in the counterclockwise direction. 
     A motion work wheel assembly  62  meshes with the cannon-pinion  52 . It drives, via its pinion  62   a , an hour wheel  64  supporting a cam  66  of the spiral type. A lever  68 , provided with a toothed sector  68   a  at one end and a finger  68   b  at the other end, is kept resting against the cam  66  by a spring diagrammatically illustrated by an arrow. A pinion  70  meshes with the toothed sector  68   a . It supports the hour hand  46 , which moves opposite a graduated scale  72  supported by the dial  60 . 
     Due to the reduction of the motion work wheel assembly, the hour wheel performs one revolution in twelve hours. The result is that the cam causes the sweeping of the graduated scale at a rate of one revolution in twelve hours, after which the hand  46  returns backward when the lever  68  arrives at the end of travel and falls. 
     As shown more particularly in  FIG. 15 , the hands  46  and  48  have a fold. In this way, they sweep a cone sector allowing an original display esthetic. 
     In the variation illustrated in  FIG. 16 , we find the wheel assemblies of the going train  14  and the barrel  12  inclined in relation to the planes A and B. In this variation, however, the axis YY of the balance is not parallel to the axes of these trains. Its incline is greater. A solution of this type makes it possible to have a greatly inclined balance, while connecting the going train  14  to the escape wheel  26  without having to have conical meshing, the difference in incline being sufficiently small for the working conditions of straight meshing not being affected. 
     The movement illustrated in  FIG. 17  is shown without its frame. One therefore only sees the wheel assemblies, and more particularly two barrels  121  and  122 , connected in series, a going train  14  provided with a differential gear  15  which drives two second wheels  141  and  142 , which drive an escapement comprising a wheel  261  and  262 , and a anchor  281  and  282 , respectively, which cause balances  301  and  302  to oscillate. This movement also comprises a motion work wheel assembly diagrammatically shown in  42  and comprising a cannon-pinion  42   a  designed to support a minute hand, not shown. 
     In this movement, the two balances  301  and  302  are inclined in relation to the axes of the wheel assemblies of the going train in particular. The incline is such that, if one defines two reference planes arranged on either side of the movement, the points of intersection of the axes of the balances  301  and  302  intersect the reference plane on the side of the movement designed to be adjacent to the wrist of the wearer which are further from the center of the movement than the points of intersection with the other plane. In one variation which was not shown, only one of the balances may be inclined. 
     The frame equipping a movement of this type may be quite similar to that of the movement described in reference to  FIGS. 1 to 4 . The integration of two balances into the second embodiment does not pose a particular problem for one skilled in the art. Such a solution is applicable without other. 
     Such a configuration also makes it possible to reduce the variation of the operation in the different positions of the movement, the two balances never being in the horizontal position simultaneously. 
     The movement according to the invention can be the object of many other variations without going beyond the scope of the invention. Thus, the energy source could, of course, comprise several barrels, connected to each other in series or in parallel. As explained above, the movement can comprise one or two balances, or even more. These balances can be arranged side by side or overlapping in whole or in part. 
     Thus, thanks to the particular characteristics presented by the different variations of the movement according to the invention, it is possible to realize a watch offering both particularly interesting technical characteristics, while also allowing original esthetic developments.