Abstract:
A watch movement with a mechanical source of energy is provided. In one implementation, the watch movement comprises a frame intended to support moving parts and defining upper and lower faces. The distance between the upper and lower faces may define a movement thickness. Further, springs may be provided for storing the energy, each being housed in a barrel. At least three barrels may be provided, the first and the second of which are superposed and the third of which is placed laterally to the other two and within their thickness.

Description:
[0001]     This application is a continuation application of prior International Application No. PCT/CH2005/000052, filed on Feb. 1, 2005, which claims priority to European (EP) Patent Application No. 04405197.7, filed Apr. 1, 2004.  
       TECHNICAL FIELD  
       [0002]     The present invention relates to watch movements having a source of mechanical energy. More particularly, the invention relates to watch movements comprising a frame intended to support moving parts and provided with an upper face and with a lower face, the distance between the faces defining the thickness of the movement. The energy may be stored in the movement in springs each housed in a barrel.  
       BACKGROUND INFORMATION  
       [0003]     A watch movement provided with two springs and with two barrels has been described in document CH 610 465. Two embodiments are envisaged. In the first, the barrels are coaxial while in the second they are placed side-by-side.  
         [0004]     A coaxial arrangement of two barrels makes it possible to produce a movement whose area remains small, but which has a relatively large thickness. In contrast, the thickness may be small when the barrels are placed side by side, but they occupy a large area of the movement, corresponding to a sector of about 180°.  
         [0005]     To produce watches with a power reserve as large as possible, document EP 1 115 040 proposes to provide a watch with four barrels, placed coaxially in pairs. Such a solution makes it possible not only to store a large amount of potential energy, thereby guaranteeing operation for more than one week, but also to restore it with a speed and a torque that are compatible with a customary going train.  
         [0006]     In this construction, the two pairs of coaxial barrels occupy practically the entire thickness of the movement and a sector of around 180°. Under such conditions, the power reserve is admittedly Large, but it is difficult to house mechanisms providing complementary functions. Thus, a power reserve indicator mechanism is placed between the barrels, within their thickness, which means that the coaxial pairs are far apart and must be linked to each other by a gear train. The area of the movement thus occupied is thereby further increased.  
         [0007]     Document WO 03/001304 describes a watch movement comprising several barrels, two at a first level and five others placed at a second level lying between the first level and the display means. Admittedly, such a solution provides a particularly large power reserve, but makes it practically impossible to display additional functions.  
       SUMMARY OF THE INVENTION  
       [0008]     An object of an exemplary embodiment of the present invention is to propose a movement for storing a large amount of energy, which uses an available volume in an optimal manner, leaving space for locating additional mechanisms. According to this embodiment, the movement comprises a frame delimited, on the one side, by a bottom plate and, on the other side, by at least one bridge, said bottom plate and bridge being configured to support moving parts and defining upper and lower faces of the movement. The distance between these faces defines the thickness of the movement. In this embodiment, springs are provided for storing the energy, each being housed in a barrel. The movement means comprise at least three barrels, a first and a second of which are superposed and define a barrel thickness, the third being placed laterally to the other two and within this barrel thickness, the third barrel not being in superposition with another barrel, and all three barrels being housed within the movement thickness.  
         [0009]     In this way, the two superposed barrels may occupy a sector of about 90° over a large portion of the thickness of the movement, while the third barrel may occupy only a portion of the thickness in its sector, thereby making it easier to integrate one or more additional mechanisms.  
         [0010]     The two superposed barrels may have a same diameter or different diameters, or they may be slightly offset one with respect to the other. However, it may be advantageous for them to be coaxial.  
         [0011]     To guarantee correct kinematic linkage conditions, it may be advantageous:  
         [0012]     for the barrels to each comprise a drum provided with a toothing, and an arbor housed in the drum, the spring being connected to the drum via one of its ends and to the arbor via the other, the arbors of the two coaxial barrels being rigidly connected to each other so as to rotate as one;  
         [0013]     for the arbors to be advantageously connected to each other by the engagement of a male member of one of the arbors in a female member of the other arbor;  
         [0014]     for the third barrel to further include a wheel provided with a toothing and mounted so as to rotate as one on its arbor; and  
         [0015]     for the drum of the first barrel to have a steel ring in which its toothing is cut and for the movement to comprise a train for winding the springs, said train meshing with the toothing of the first barrel.  
         [0016]     Thanks to the arrangement defined above, it may be possible to provide the movement with a mechanism, at least some of the constituent components of which may lie in the thickness of the superposed barrels and may be placed between the third barrel and one of the faces of the movement. consequently, this mechanism does not modify the external dimensions of the movement. or example, this mechanism may provide an indication of a power reserve, winding and time-setting or a chronograph function.  
         [0017]     Advantageously, a winding and time-setting mechanism, which may comprise a time-setting stem extending radially outward and able to move rotationally and translationally along an axis parallel to the faces of the movement, may lie at least partly in the space between the third barrel and one of the faces of the movement. The stem may advantageously be oriented in such a way that its axis is approximately a bisector of an angle defined by two straight lines connecting pivot axes of the barrels to a center of the movement.  
         [0018]     In accordance with one embodiment, a power reserve indication mechanism may advantageously include a differential gear comprising an output connected to power reserve indication organs or members and two inputs connected by gear trains, respectively, to wheels for tensioning the springs on the one hand, and for driving a going train on the other hand. To simplify the structure of the movement, the third barrel may include an arbor drilled axially right through. At least one of the wheels of these gear trains may include a rod engaged in the drillhole of the arbor in order for wheels of these gear trains placed near the lower and upper faces to possibly be kinematically linked.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]     Other features, advantages, and embodiments of the invention will emerge from the following description, which refers to the appended drawings in which:  
         [0020]      FIG. 1  is a view of a movement, according to one exemplary embodiment of the invention, in cross section taken on a plane passing through the axes of the barrels;  
         [0021]      FIG. 2  shows, in a perspective view from below, the trains, the escapement and the balance of the exemplary movement of  FIG. 1 ;  
         [0022]      FIG. 3  is a plan view of one exemplary embodiment of the winding and time-setting mechanism;  
         [0023]      FIG. 4  illustrates, in cross section, an exemplary embodiment of a power reserve mechanism of the movement;  
         [0024]      FIG. 5  and  FIG. 6  are cross sections through a movement comprising a power reserve mechanism according to a further exemplary embodiment; and  
         [0025]      FIG. 7  is a cross section view of an alternative exemplary embodiment of the barrel arrangement in the movement. 
     
    
     DETAILED DESCRIPTION  
       [0026]     The movement shown in the drawings comprises a frame, visible more particularly in  FIG. 1 , comprising a bottom plate  10  and bridges, notably a barrel bridge  12 . The outer face of the bottom plate  10  defines the upper face  14  of the movement, which may be covered by a dial, while the outer face of the bridges defines the lower face  16  of the movement, which is generally on the bottom side of the case.  
         [0027]     The bridges may be positioned on the bottom plate  10  in the conventional way by means of feet, and fixed by means of screws—not shown in the drawings to avoid overloading it.  
         [0028]     Three barrels with the references  18 ,  20  and  22  respectively are installed between the bottom plate  10  and the bridge  12 . The barrels  18  and  20  are coaxial. They are mounted so as to pivot between the bottom plate  10  and the bridge  12  on a rod  24  which is cylindrical in its central part  24   a  and has, at its ends, two pivots  24   b  and  24   c  engaged in holes in the bottom plate  10  and in the bridge  12 , respectively.  
         [0029]     The barrels  18  and  20  each comprise a drum identified by the letter a, a cover b and an arbor c. The drums a are provided on their cylindrical outer wall with a toothing d whose function will be explained later. They have in their central part a tubular portion e in which the rod  24  is engaged.  
         [0030]     Advantageously, the toothing  20   d  may be formed in a steel ring mounted on the drum  20   a.    
         [0031]     The arbors c are drilled-out and possess two tubular portions f and g connected by an annular portion h. The smaller diameter tubular portions f are mounted on and pivot about the rod  24  in line with each other. At their free end are structures of complementary shape, which interlock so that they rotate as one. The larger diameter tubular portions g are engaged on the tubular portions e of the drum and are provided with a hook, thus forming a core.  
         [0032]     Springs  26  and  27  are housed in the barrels  18  and  20 , respectively, and fixed at one end to the inside wall of the drum a and at the other to the hook of the tubular portion g which forms the core.  
         [0033]     The covers b snap onto the drums a in the conventional manner.  
         [0034]     The barrel  22  comprises a drum  22   a  and an arbor  22   b.  The drum  22   a  is provided with a toothing  22   c  around its periphery, meshing with the toothing  18   d  of the barrel  18 . The arbor  22   b  is provided in its central part with a portion having a hook and forming a core  22   d,  and at its ends with two pivots  22   e  and  22   f  engaged in bearings in the bottom plate  10  and in the bridge  12 , respectively.  
         [0035]     The arbor  22   b  carries, fixed rigidly between the core  22   d  and the pivot  22   f,  a wheel  28  that covers the open side of the drum  22   a.  A spring  29  is installed in the drum  22   a  and fixed to the latter by one of its ends and to the core  22   d  by the other.  
         [0036]     As can be seen in  FIG. 1 , the coaxial barrels  18  and  20  may occupy a large part of the thickness of the movement. The barrel  22 , being positioned by the side of the barrels  18  and  20 , and within their thickness, leaves a space between itself and the faces  14  and  16  that may be used to house all or part of a mechanism, as will be explained later.  
         [0037]     The springs installed in the barrels  18 ,  20  and  22  may be wound by a winding mechanism which will be described later, using a wheel that meshes with the toothing  20   d  of the barrel  20 . In this ways the drum  20   a  is rotated. The spring  27  which it contains, and one end of which is hooked to the wall of the drum  20   a,  is wound by the rotation of the drum. The arbor  20   c,  to which the other end of the spring  27  is fixed, is subjected to a torque, which is transmitted to the arbor  18   c.    
         [0038]     Since the latter is connected to one end of the spring  26  housed in the barrel  18 , this spring  26  is also wound and applies a torque to the drum  18   a  through its other end. The toothing  18   d  then rotates the toothing  22   c  of the barrel  22 , which thus winds the spring  29  that it contains, thereby applying a torque to the arbor  22   b,  which is transmitted to the going train by the wheel  28 , as will be explained below.  
         [0039]     The going train is clearly visible in  FIG. 2 . Its various wheels pivot, of course, in the frame, which has not been shown in order to simplify the reading of the drawing. This train may comprise a center wheel  30 , a third wheel  32 , a fourth wheel  34  and an escape wheel  36 . Each of these wheels comprises a pinion identified by the letter “a” and a disk identified by the letter “b,” which is provided with a toothing identified by the letter “c.” 
         [0040]     The barrel  22  rotates the center wheel  30  by the meshing of the wheel  28  with the pinion  30   a.  The going train is designed so that the center wheel makes one revolution per hour. Its toothing  30   c  meshes with the pinion  32   a  of the third wheel  32 , which rotates as one with the disk  32   b  and the toothing  32   c  which meshes with the pinion  34   a  of the fourth wheel  34 . The latter, which makes one revolution in one minute, meshes through its toothing  34   c  with the pinion  36   a  of the escape wheel  36 , and the last-mentioned drives, in the conventional manner, the pallet lever and the balance, which have not been given reference symbols.  
         [0041]     A tube  44  may be mounted rigidly in the center of the bottom plate and extends beyond the face  14 . Its function is to enable the wheels carrying the central hands to pivot.  
         [0042]     More precisely, to display the minutes, the going train may also have a central wheel  46  meshing with a second pinion  32   d  of the third wheel  32  and supporting a cannon pinion  48  mounted with friction and engaged on the tube  44 . The cannon pinion  48  is designed to be able to carry a minute hand.  
         [0043]     The movement may also includes a motion work train, the first part of which is the cannon pinion  48 . A minute wheel  50 , comprising a pinion  50   a  and a disk  50   b  with a toothing  50   c,  pivots on the bottom plate  10  and its toothing  50   c  meshes with the cannon pinion  48 . Its pinion  50   a  drives an hour wheel  52  engaged by its pipe  52   a  on the cannon pinion  48 , this pipe being designed to hold an hour hand.  
         [0044]     An exemplary embodiment of a winding and time-setting mechanism is shown in  FIG. 3 . In  FIG. 3 , the frame has again been omitted in order to make the components of this mechanism more clearly visible.  
         [0045]     This mechanism may comprise, in the conventional manner, a winding and time-setting stem  54 , a setting lever  56 , a clutch lever  58 , and a jumper bridge  60 .  
         [0046]     The stem  54  is mounted so as to pivot in the bottom plate  10  about an axis parallel to the faces  14  and  16  of the movement and extending outward from the center of the movement. This axis may approximately be the bisector of an angle defined by two straight lines connecting the pivot axes of the barrels  18  and  20  on the one hand, and of the barrel  22  on the other, to the center of the movement.  
         [0047]     Mounted on the stem  54  are a clutch wheel  62  and a winding pinion  64  engaging or not engaging with each other depending on the radial position of the stem and its direction of rotation, via a Breguet toothing identified by the letter a. The clutch wheel  62  also has a contrate toothing  62   b  and the winding pinion  64  has a radial toothing  64   b.    
         [0048]     A crown wheel  66  is placed below the clutch wheel  62 , mounted on the bridge of the barrel  12  and engaged with the winding pinion  64  via its radial toothing  64   b,  and also with an intermediate wheel  68  comprising a pinion  68   a  that meshes with the crown wheel  66  and a disk  68   b  provided with a toothing  68   c,  which drives the drum  20   a  via its toothing  20   d.    
         [0049]     Thus, and as generally occurs in mechanical watches, the barrel springs  26 ,  27  and  29  may be wound by rotating the stem  54  when it is in the pushed-in position. This rotation drives the clutch wheel  62 , engaged with the winding pinion  64 , via their toothings  62   a  and  64   a  (e.g., Breguet toothings), which rotates the crown wheel  66  and the intermediate wheel  68  that meshes with the toothing  20   d  of the drum  20 .  
         [0050]      FIG. 4  shows an exemplary embodiment of a power reserve indicator mechanism comprising a differential gear. It is controlled on the one hand by means of a wheel  70  mounted so as to rotate as one on the arbor  22   b  of the barrel  22 , which rotates synchronously with the going train, and, on the other hand, by means of a linkage train engaged with the crown wheel  66 , this linkage train being not shown in the drawing otherwise it would mask the other constituents.  
         [0051]     More precisely, the differential gear comprises a planet wheel  72  mounted so as to rotate freely on an arbor  74  and positioned axially by stops  75  defined by the bottom plate  10  and an intermediate bridge  76  carried by the bottom plate  10 . The planet wheel is provided with a toothing  72   a  that meshes, via a wheel  77 , with the wheel  70  carried by the arbor  22   b  of the barrel  22 . It thus forms the winding entry of the power reserve indicator.  
         [0052]     The planet wheel  72  carries a satellite wheel  78  comprising a wheel  78   a  and a pinion  78   b.  The arbor  74  pivots in bearings that the bottom plate  10  and the bridge  76  have, It carries a lantern pinion  80 , which meshes with the pinion  78   b  and also an output wheel  82  that rotate as one, the function of which will be explained later.  
         [0053]     The lantern pinion  80  is provided with a pipe  80   a  frictionally mounted on the arbor  74  in order to form the lanterning, and on which an unwinding entry wheel  84 , which comprises a pinion  84   a  and wheel  84   b,  pivots. The pinion  84   a  meshes with the wheel  78   a  of the satellite wheel  78 , while the wheel  84   b  is kinematically linked to the crown wheel  66  via the linkage train.  
         [0054]     Thus, when the user winds his watch, the crown wheel  66  drives the wheel  84  via the linkage train. Its pinion  84   a  engages with the wheel  78   a  of the satellite wheel  78 . Since the planet wheel  72  is engaged with the wheel  70  and, thereby, with the arbor  22   b  of the barrel  22 , it rotates only very slowly. The satellite wheel  78 , therefore, remains virtually immobile about the axis of the planet wheel. However, it rotates about its own axis and its pinion  78   b  drives the wheel  80 . The latter makes the arbor  74  rotate via its lanterned pipe  80   a  and the output wheel  82 .  
         [0055]     The rotation of the barrel  22 , which drives the going train, furthermore rotates the wheel  70  and the wheel  77 . The latter, engaged with the planet wheel  72 , rotates it. Since the crown wheel  66  is immobile, the wheel  84  is likewise immobile. This means that the wheel  78   a  of the satellite wheel rolls over the pinion  84   a,  the pinion  78   b  rotating the lantern pinion  80  and, with it, the arbor  74  that rotates the output wheel  82 , but in the opposite direction to that caused by the rotation of the crown wheel  66 .  
         [0056]     The power reserve may be displayed by means of a rack  86  mounted so as to slide in the bottom plate  10  and kinematically linked to the wheel  82  via two wheels  88  and  90 . The rack may be provided with an index visible on the dial.  
         [0057]     In the exemplary embodiment of the movement described above, the arrangement of the barrels  18 ,  20  and  22  makes it possible to house a considerable portion of the components of the time-setting and power-reserve mechanisms in the thickness of the barrel  18  and above the barrel  22 , which represents a particularly advantageous distribution of the components of the movement.  
         [0058]     The movement according to the further exemplary embodiment shown in  FIG. 5  and  FIG. 6  is similar to that described above. Its power-reserve indicator mechanism differs therefrom essentially by the structure of the train for driving the indicator.  
         [0059]      FIG. 5  and  FIG. 6  again show the barrel  22 , its arbor  22   b  and the rack  86 . The latter, mounted so as to move translationally along the bottom plate  10 , carries an index indicating, with reference to a scale on the dial of the watch, the tensioning state of the springs.  
         [0060]     They also again show the differential gear with its planet wheel  72 , mounted on the arbor  74 , and its satellite wheel  78  formed from the wheel  78   a  and the pinion  78   b.  The arbor  74  carries the wheel  80  provided with the pipe  80   a  frictionally mounted on the arbor  74 , and also the wheel  82  which rotates as one with the arbor  74 .  
         [0061]     As may be seen in  FIG. 6 , the planet wheel  72  is linked to the arbor  22   b  of the barrel  22  by a gear train comprising a first gear  91  that rotates as one with the arbor  22   b,  a second gear  92  and a wheel  93  that includes a wheel  93   a,  engaged with the gear  92 , and a pinion  93   b  meshing with the planet wheel  72 . This gear train drives the power reserve indicator during spring unwinding.  
         [0062]     To control the movement of the power reserve indicator during spring winding, it is necessary to pass from the lower face  16 , near which the toothing  20   d  of the barrel  20  lies, which ensures spring winding, to the upper face  14  near which the differential gear lies.  
         [0063]     As may be seen in  FIG. 5 , the barrel arbor  22   b  may be drilled-out axially and may serve as housing for a rod  94  that passes right through said arbor. This rod carries, so that they rotate as one, a wheel  94   a  kinematically linked to the toothing  20   d  of the barrel  20  and a gear  94   b  that drives the gear train that controls the displacement of the power reserve indicator during spring winding. This gear train comprises a wheel  95 , formed from a pinion  95   a  engaged with the gear  94   b  and from a wheel  95   b  and a gear  96  connecting the wheel  95   b  to the pinion  80   a.    
         [0064]     Finally, the wheel  82  provides (see  FIG. 6 ) the linkage between the differential gear and the rack  86  via a wheel  97 , comprising a toothed wheel  97   a  engaged with the wheel  92  and a pinion  97   b  driving the rack  86 .  
         [0065]     The operation of this exemplary movement is the same in its principle, the differential gear making it possible to drive in one direction the display during spring winding and in the other direction during unwinding. It is quite clear that the various wheels linking, on the one hand, the toothing  20   d  via which the winding takes place and, on the other hand, the arbor  22   b  to the differential gear may advantageously be designed in such a way that the displacement of the rack is the same for the same winding or unwinding angle. Such a design is within the competence of a person skilled in the art.  
         [0066]      FIG. 7  shows an alternate exemplary embodiment of the movement in which the structure of the barrels and the way in which they are mounted in their frame are different from those described above. However, the same components therein bear the same references. The essential difference relates to the arbors of the coaxial barrels  18  and  20 .  
         [0067]     In this variant, the barrel  18  is provided with an arbor  98  comprising a central part  98   a  housed in the space lying between the drum  18   a  and the cover  18   b  and forming a core, a cylindrical portion  98   b  adjacent the central part  98   a  and engaged in a hole at the bottom of the drum  18   a,  in order to form a pivot. The portion  98   b  is extended by a pivot  98   c  that pivots in the bottom plate  10 . A linking portion  98   d  and a cylindrical portion  98   e  extend from the central portion  98   a  toward the bridge  12 . The linking portion is of cylindrical shape provided with two flats, the function of which will be explained below. The cylindrical portion  98   e  is provided at its end with a pivot  98   f  engaged in a bearing that this bridge has.  
         [0068]     A ring  98   k,  advantageously made of steel, is slipped onto the arbor  98 , surrounding the linking portion  98   d.  The outside diameter of the ring  98   k  is slightly smaller than that of the hole in the cover  18   b,  in such a way that it can pivot in the cover  18   b  of the barrel  18 . Because of the flats with which this linking portion  98   d  is provided, there exists, between said linking portion and the ring  98   k,  spaces intended to take the place of housings, as will be explained below.  
         [0069]     The barrel  20  includes an arbor  99  that has a central part  99   a  forming a core. It is drilled right through and engaged on the cylindrical portion  98   e.  The arbor  99  is provided right through its central part  99   a  with two cylindrical portions  99   b  and  99   c,  which are engaged in the drum  20   a  and in the cover  20   b,  respectively, and form pivots. The end of the portion  99   b  is extended by two fingers  99   d  engaged in the housings that the ring  98   k  and the linking portion  98   d  form between them, thus making the arbors  98  and  99  rotate as one.  
         [0070]     In this variant, the barrel drums and covers are advantageously made of a beryllium-copper alloy.  
         [0071]     This second variant makes it possible to reduce the number of constituent components, since the arbor  98  provides both functions of the rod  24  and of the arbor  20   c  of the first variant.  
         [0072]     It goes without saying that the movement described may be subject to many other variants without thereby departing from the scope of the invention. This is particularly the case with regard to the way in which the barrels are linked together. It is also possible, for certain particular applications, to place the superposed barrels so that they are slightly offset one with respect to another.  
         [0073]     It is also conceivable to place one or more barrels in addition to the three described above. Nothing would prevent a fourth barrel from being incorporated into the movement, independently or integrated into the kinematic chain of the going train.  
         [0074]     Thus, thanks to the structure of movements consistent with embodiments of the invention, it may be equipped with many other mechanisms, whether or not placed in the space thus made available. For example, mention may be made of a perpetual calendar, a countdown timer, a repeater, etc.