Patent Publication Number: US-8982674-B2

Title: Device for correcting a timepiece display mechanism

Description:
This is a National Phase Application in the United States of International Patent Application PCT/EP 2008/056776 filed Jun. 2, 2008, which claims priority on European Patent Application No 07109530.1 of Jun. 4, 2007. The entire disclosures of the above patent applications are hereby incorporated by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to the field of horology. More specifically, it concerns a device for correcting a mechanism displaying a time indication, such as a date, day of the week, month etc. 
     BACKGROUND OF THE INVENTION 
     Mechanisms displaying a time indication generally include one or more display members, such as discs or rings, actuated in rotation by a drive mechanism. Corrections devices for such display mechanisms are well known to those skilled in the art. They mainly include a winding stem arranged to occupy at least one time indication correcting position, a pinion that is secured in rotation to the winding stem, an intermediate wheel meshed with the pinion when the stem is in the correcting position and a corrector wheel set which is activated by the intermediate wheel and cooperates with a first display member. The unit is generally mounted on a bottom plate, on the dial side. 
     When the display mechanism has two display members, the corrector wheel set is slidably mounted between two correcting positions, so that the change from one correcting position to the other occurs by reversing the direction of rotation of the winding stem. Thus, the corrector wheel set is, for example, mounted on a lever actuated by the intermediate wheel. The assembly formed by the intermediate wheel, the lever and the corrector wheel set is located at 3 o&#39;clock, in proximity to the winding stem. It takes up a considerable amount of space, which makes it inconvenient to incorporate if there are other parts in proximity to the winding stem. This is the case, particularly, when chronograph counter arbours pass through the bottom plate in proximity to the winding stem. The space available for the display mechanism corrector device is thus greatly limited. 
     One solution to this difficulty consists in moving the lever-corrector wheel set unit to another section of the bottom plate, for example, to 9 o&#39;clock, using a series of intermediate wheels, which are mounted to rotate freely about the arbours of the various counters. This solution takes a great deal of space on the bottom plate. It is difficult to implement if the plate is already occupied by a drive mechanism. 
     The present invention overcomes this drawback, by proposing a device for correcting the time indication of a display mechanism, wherein the lever-corrector wheel set unit is moved to one of the 9 o&#39;clock, 6 o&#39;clock or 12 o&#39;clock sectors of the plate, thereby releasing useful space on the plate. 
     SUMMARY OF THE INVENTION 
     In particular, the invention broadly concerns a device for correcting a time indication provided by a timepiece display mechanism of the type including a first display member that has:
         a winding stem arranged to occupy at least one time indication correcting position,   a pinion mounted on the winding stem and secured in rotation thereto,   an intermediate corrector wheel that is kinematically connected to the pinion when the stem is occupying the correcting position, and   a corrector wheel set that cooperates with the display member and is actuated by the intermediate corrector wheel,
 
characterized in that the intermediate corrector wheel is formed of a ring with an inner circumference and an outer circumference, at least one of which has a toothing that meshes, at least indirectly, with the corrector wheel set.
       

     Owing to its ring-shaped geometry, the intermediate corrector wheel frees space inside its inner circumference, which means that parts, for example counter arbours, can be housed therein. Moreover, if the diameter of the intermediate corrector wheel is large compared to the other parts of the correction device, the lever-corrector wheel set unit can be moved away from the immediate vicinity of the winding stem, thereby freeing a significant amount of space inside the intermediate corrector wheel. In one advantageous embodiment, the intermediate corrector wheel surrounds all of the counter arbours, and moves the lever-corrector wheel set unit to 9 o&#39;clock. 
     More specifically, in accordance with a first illustrative embodiment of the present invention, a device ( 14 ) is provided for correcting a time indication, supplied by a display mechanism ( 12 ) for a timepiece, of the type including a first display member ( 20 ) that includes: (a) a winding stem ( 50 ) arranged to occupy at least one time indication correcting position (A), (b) a pinion ( 52 ) that is mounted on the winding stem ( 50 ) and secured thereto in rotation, (c) an intermediate corrector wheel ( 58 ) kinematically connected to the pinion ( 52 ) when the stem ( 50 ) is occupying the correcting position (A), and (d) a corrector wheel set ( 68 ) that cooperates with the display member ( 20 ) and is actuated by the intermediate corrector wheel ( 58 ), characterized in that the intermediate corrector wheel ( 58 ) is formed of a ring ( 60 ) with an inner circumference and an outer circumference, at least one of which is fitted with a toothing ( 62 ), which is meshed, at least indirectly, with the corrector wheel set ( 68 ). In accordance with a second illustrative embodiment of the present invention, the first illustrative embodiment is modified so that the intermediate corrector wheel ( 58 ) is guided in rotation by one of the inner or outer circumferences thereof. In accordance with a third illustrative embodiment of the present invention, the first illustrative embodiment is modified so that the intermediate corrector wheel ( 58 ) is guided in rotation by a rib secured to the ring ( 60 ). 
     In accordance with a fourth illustrative embodiment of the present invention, the first, second and third illustrative embodiments are further modified so that it is mounted on a bottom plate ( 10 ) through which several arbours ( 15 ,  16 ,  18 ) pass, and in that the intermediate corrector wheel ( 58 ) is mobile in rotation about at least one of the arbours ( 16 ). In accordance with a fifth illustrative embodiment of the present invention, the fourth illustrative embodiment of the invention is modified so that the bottom plate ( 10 ) is traversed by three arbours ( 15 ,  16 ,  18 ), one ( 15 ) of which is centred relative to the bottom plate ( 10 ), and the two others ( 16 ,  18 ) are off-centre, and in that the intermediate corrector wheel ( 58 ) is mobile in rotation about the three arbours ( 15 ,  16 ,  18 ). In accordance with a sixth illustrative embodiment of the present invention, the fifth illustrative embodiment is further modified so that the display member ( 20 ) is formed of a ring ( 22 ) and in that the diameter of the intermediate corrector wheel ( 58 ) is close to that of the display member ( 20 ). In accordance with a seventh illustrative embodiment of the present invention, the sixth illustrative embodiment is further modified so that the corrector wheel set ( 68 ) is arranged at approximately 9 o&#39;clock on the bottom plate ( 10 ). 
     In accordance with an eighth illustrative embodiment of the present invention, the fourth illustrative embodiment is further modified so that the intermediate corrector wheel ( 58 ) is mobile in rotation about a single off-centre arbour ( 16 ). In accordance with a ninth illustrative embodiment of the present invention, the eighth illustrative embodiment is further modified so that the display member ( 20 ) is formed of a ring ( 22 ), and in that the diameter of the intermediate corrector wheel ( 58 ) is close to that of the display member ( 20 ). In accordance with a tenth illustrative embodiment of the present invention, the ninth illustrative embodiment is further modified so that the corrector wheel set ( 68 ) is arranged at approximately 6 o&#39;clock on the bottom plate ( 10 ). 
     In accordance with an eleventh illustrative embodiment of the present invention, the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth and tenth illustrative embodiments are further modified so that the corrector wheel set ( 68 ) is slidably mounted between a first position (A′) where it cooperates with the first display member ( 20 ) and a second position (B′) where it cooperates at least indirectly with a second display member. In accordance with a twelfth illustrative embodiment of the present invention, the eleventh embodiment is further modified so that the corrector wheel set ( 68 ) is mounted on a lever ( 70 ). In accordance with a thirteenth illustrative embodiment of the present invention, the eleventh illustrative embodiment is further modified so that the corrector wheel set ( 68 ) is slidably mounted in an oblong hole. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the present invention will appear more clearly from the following detailed description of an example embodiment of a display mechanism correction device according to the invention. This example is given purely by way of non-limiting illustration, with reference to the annexed drawing, in which: 
         FIG. 1  is a top view of a correction device according to the invention, 
         FIGS. 2 to 4  are cross-sections of the device along the respective axes AA, BB and CC, and 
         FIGS. 5 and 6  are variants of the correction device according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS 
       FIG. 1  shows a bottom plate  10  for a timepiece, on which there are mounted, on one side, a mechanical or electromechanical movement (not shown), fitted with a chronograph mechanism, and, on the other side, a time indication display mechanism  12  and its correction device  14 . A central arbour  15  for carrying hour and minute display members (not shown) and two arbours  16  and  18 , respectively located at 4 o&#39;clock and 8 o&#39;clock, belonging to minute and hour counters of the chronograph mechanism, pass through bottom plate  10 . 
     The time indication display mechanism  12  is of a conventional type. It has a digital date indicator  20 , formed of a ring  22  fitted with an inner toothing  24 . The date indicator  20  is mounted on a calendar plate  26 , which is screwed to plate  10  and has a recess  28  provided for this purpose. It is angularly positioned by a jumper spring  29  and held axially and guided in rotation by a retaining plate  30 , which is secured to calendar plate  26 . Display mechanism  12  also includes a day display member, such as a hand, which is not visible in  FIG. 1 . The day display member is mounted at the centre of plate  10  and secured to a wheel set  32  formed of a day star wheel  34  and a correction star wheel  36 . 
     The date indicator  20  and the day display member are driven in rotation by a drive mechanism  38 , which is located at 11 o&#39;clock and includes a drive wheel set  40 , formed of a wheel  42  and a finger  44 , secured to each other in rotation. Finger  44  cooperates with toothing  24  and also with day star wheel  34 . Wheel  42  is driven by a pinion  46  that is kinematically connected to the movement by an arbour that passes through plate  10 . 
     The display mechanism  12  thus described is positioned behind a dial (not shown). It can display the date, through a first aperture made in the dial, and the corresponding day of the week, via the day hand, which cooperates with day indications affixed to the dial. 
     Reference will now usefully be made to  FIGS. 2 to 4 , which illustrate the correction device  14 , seen along cross-sections AA, BB and CC. Correction device  14  of display mechanism  12  has, in a conventional manner, a winding stem  50 , which is guided in rotation in plate  10 . A sliding pinion  52  is secured in rotation to winding stem  50 , and can move between a correcting position A and a winding position B. In correcting position A, it meshes with a first intermediate wheel  54 , which is mounted to rotate freely on plate  10 , and meshed with a second intermediate wheel  56 , mounted to rotate freely on calendar plate  26 . 
     The second intermediate wheel  56  is meshed with an intermediate corrector wheel  58 , formed of a ring  60  with an inner toothing  62 . Intermediate corrector wheel  58  is guided in rotation by its outer circumference, on calendar plate  26 . A recess  63  is provided for this purpose in calendar plate  26 . It is also held axially by three shouldered screws  64   a ,  64   b ,  64   c , which are distributed angularly on the periphery thereof. The diameter of intermediate corrector wheel  58  is close to the diameter of date indicator  20 , and it is positioned approximately centred about arbours  15 ,  16  and  18  of the various elements of drive mechanism  38  and correction device  14 . 
     Intermediate corrector wheel  58  actuates a double corrector  66  mounted at 9 o&#39;clock on calendar plate  26 , and formed of a corrector wheel set  68  mounted on a lever  70 . Lever  70  is pivotably mounted between first and second correcting positions, respectively A′ and B′, about a pivoting axis XX perpendicular to bottom plate  10 . It includes a plate  72  mounted on a control wheel  74 , whose axis of rotation merges with pivoting axis XX, meshed with intermediate corrector wheel  58 . Control wheel  74  is also partially secured to plate  72  via a friction spring  76 . A pinion  78  is mounted on plate  72 , secured in rotation to control wheel  74 , meshed with corrector wheel set  68 . In first correcting position A′, the corrector wheel set meshes with toothing  24  of date indicator  20 , and in second correcting position B′, it meshes with an intermediate star wheel  80 , which is meshed with correction star wheel  36 . In a variant of this embodiment, corrector wheel set  68  is slidably mounted in an oblong hole made in calendar plate  26 , in accordance with a technique well known to those skilled in the art. 
     It will be noted that the correction device  14  thus described has two important advantages compared to a conventional device. First of all, the ring-shaped geometry of intermediate corrector wheel  58  frees space at the centre thereof. This space is occupied, in this case, by parts belonging to drive mechanism  38 , correction device  14  and by arbours  15 ,  16  and  18 . Secondly, the intermediate corrector wheel  58  has a diameter close to that of the date indicator  20 . In example, the intermediate corrector wheel  58  has a diameter of two-thirds of the diameter of bottom plate  10 . Because the diameters of the drive mechanism and the date indicator are close, intermediate corrector wheel  58  can move double corrector  66 , which cannot be mounted in proximity to winding stem  50 , because of the presence of minute counter arbour  16  at 4 o&#39;clock. In the present case, double corrector  66  is moved to 9 o&#39;clock, but it could also be at 6 o&#39;clock or 12 o&#39;clock, or any other place on bottom plate  10  free to receive it. Moreover, double corrector  66  is moved relative to bottom plate  10 , without any useful space being lost on the plate. This arrangement of correction device  14  is advantageous for a bottom plate  10  that is pierced with several arbours, practically whatever the position of the arbours. It will be seen below that other arrangements of correction device  14  may be envisaged for particular arbour positions. 
     The operation of correction device  14  is as follows. When winding stem  50  is actuated clockwise, with sliding pinion  52  in correction position A, first intermediate wheel  54  is driven anti-clockwise, and it thus drives second intermediate wheel  56  clockwise. Wheel  56  meshes with intermediate corrector wheel  58 , which is rotating clockwise, and in turn drives control wheel  74  of lever  70  clockwise. Control wheel  74  pivots plate  72  under the effect of friction wheel  76 , until intermediate corrector wheel set  68  meshes with date indicator  20 . Control wheel  74  is then uncoupled from plate  72 , and actuates corrector wheel set  68  via pinion  78 . Corrector wheel set  68  corrects date indicator  20  by rotating it anti-clockwise. When winding stem  50  is actuated anti-clockwise, with the sliding pinion in correction position A, the set of intermediate wheels  54 ,  56 ,  58  rotate in the opposite direction to the preceding direction, and lever  70  pivots anti-clockwise until corrector wheel set  68  meshes with intermediate star wheel  80 . The latter drives correction star wheel  36  clockwise, thus allowing correction of the day display member. 
     We will now refer to  FIGS. 5 and 6 , which illustrate variants of correction device  14  according to the invention. 
     The correction device  14  illustrated in  FIG. 5  differs from the device illustrated in  FIGS. 1 to 4 , in that the diameter of intermediate corrector wheel  58  is smaller than the radius of date indicator  20  and in that it is off-centre relative to bottom plate  10 , so as to occupy essentially the quarter located between 3 o&#39;clock and 6 o&#39;clock. The space freed at the centre of wheel  58  is essentially occupied by the minute counter arbour  16 . It will be noted that arbour  15  at the centre of bottom plate  10  is excluded from this space, unlike the preceding embodiment. Double corrector  66  is located at 6 o&#39;clock, i.e. between minute counter arbour  16  and hour counter arbour  18 . Moreover, toothing  24  of intermediate corrector wheel  58  is located on its outer, not inner circumference and it is the inner circumference that guides wheel  58  in rotation. This arrangement is suitable for a bottom plate  10  that is pierced with a central arbour  15 , and two off-centre arbours  16  and  18 , respectively at 4 o&#39;clock and 8 o&#39;clock. 
     Finally, the correction device  14  illustrated in  FIG. 6  differs from the preceding devices in that the diameter of intermediate corrector wheel  58  is smaller than the diameter of date indicator  20 , but greater than its radius. Intermediate corrector wheel  58  is also off-centre relative to bottom plate  10 , so as to occupy essentially the half comprised between 9 o&#39;clock and 3 o&#39;clock. The central arbour  15  is included in the space freed at the centre thereof. As in the preceding example, toothing  24  is an outer and not an inner toothing. The arrangement thus described is suitable for a plate that is pierced with four arbours  15 ,  16 ,  18 ,  82  located respectively at the centre, at 4 o&#39;clock, 8 o&#39;clock and 6 o&#39;clock. 
     Other corrector device arrangements may be devised to suit requirements. All of these arrangements have in common a ring-shaped intermediate corrector wheel, fitted with an inner or outer toothing that is guided in rotation by one of its circumferences. 
     Of course, the corrector device according to the invention is not limited to the embodiments that have just been described and various simple alterations and variants could be envisaged by those skilled in the art, without departing from the scope of the invention as defined by the annexed claims. 
     It will be noted, in particular, that in the preceding description, intermediate corrector wheel  58  is guided in rotation by its outer or inner circumference. In a variant, intermediate corrector wheel  58  could be, for example, formed of a ring  60  fitted with a circular rib, engaged in a groove made in calendar plate  26 . 
     It will also be noted that correction device  14  does not include a second intermediate wheel  56  in the variants illustrated in  FIGS. 5 and 6 . It will be clear, likewise, that the first intermediate wheel  54  is not indispensable to correction device  14 , and that intermediate corrector wheel  58  can be meshed directly with sliding pinion  52 .