HK1140027B - Timepiece including a striking mechanism - Google Patents

Description

Timepiece including a striking mechanism

Technical Field

The invention relates to a timepiece, in particular a wristwatch, comprising: a striking mechanism, a time display device driven by a timepiece movement, and a time-setting mechanism, particularly comprising: a time-setting gear train connected to the display device, a manual control stem and a clutch wheel driven in rotation by said stem and able to slide thereon to mesh with the first intermediate wheel of the time-setting gear train to transmit the rotation of the clutch wheel to the time display device.

Background

EP patent application No.1429214 discloses a chronograph of this type, which states that a time-setting operation while the striking mechanism is working can cause considerable damage and should therefore be avoided. The proposed solution utilizes a locking mechanism controlled by the active part of the striking mechanism and locking the conventional rocker of the time-setting mechanism so that the clutch wheel controlled by the lever can no longer move to engage with the time-setting train.

This locking is effective, but if the user, who is accustomed to feeling resistance each time the control stem crown is pulled, applies too strong a traction force, there is still a risk of damage. This may damage the time-setting mechanism or the locking mechanism or, if the locking is overcome, even the striking mechanism.

Disclosure of Invention

The object of the present invention is to overcome the aforementioned drawbacks of the prior art by reliably ensuring that the timepiece is not damaged by inadvertent operation by the user when the striking mechanism is no longer in the rest position.

To this end, a timepiece of the type indicated in the preamble above is provided, characterized by a disengagement means and a disengagement control means, the disengagement means being inserted into the time-setting train and being arranged in such a way that: when it is activated, the transmission of the rotary motion of said first intermediate wheel to the time display device is blocked and the disengagement control means are driven by means of the mobile part of the striking mechanism to activate the disengagement means when the striking mechanism is operated.

Thus, unlike the principle provided in EP patent application No.1429214, when the striking mechanism is released, the time-setting mechanism is not locked, but simply disengaged, so that the kinematic connection between the first intermediate wheel of the time-setting train and the display device is temporarily interrupted. This disengagement can be performed regardless of the position of the control stem and/or the clutch wheel. In this case, if the user pulls out the control stem and tries to set the time, he can rotate the crown together with the stem and the clutch wheel without any influence on other elements and thus without easily causing any damage. Moreover, when he does not encounter resistance and observes that the display element is not moving, he realizes that the operation he is trying to do is ineffective.

In fact, the invention results in the presence of two coupling means in series between the manual control stem and the time display means, the first coupling means being formed by the conventional coupling of the clutch wheel with the first intermediate wheel of the time-setting train. The solution according to the invention is easier to implement and more reliable than the solution envisaged in EP patent No.1933212, which comprises: when the striking mechanism is operated, the clutch wheel is stopped in an intermediate position in which it is no longer engaged with the first intermediate wheel. In any case, this prior solution has not been disclosed at the priority date of the present application.

Preferably, the disengagement means comprises: a movable intermediate wheel in the time-setting train, the movable intermediate wheel being moved by a disengagement control device between a coupling position, in which it is engaged with at least one element of the time-setting train, and a disengagement position, in which it is released from said element; the disengagement means also comprise an elastic element having the function of keeping the movable intermediate wheel in its coupling position. The intermediate wheel may be moved axially or laterally as selected by the designer.

Further characteristics and advantages of the invention will appear in the following description of various embodiments, given by way of non-limiting example with reference to the accompanying drawings.

Drawings

Fig. 1 is a schematic plan view of part of the elements of a watch with a striking mechanism according to a first embodiment of the invention, showing the time-setting mechanism, the time-display hands-on mechanism, the means for disengaging the time-setting train and the part of the striking mechanism in the rest position.

Fig. 2 is a view similar to fig. 1, in a position in which the dotting mechanism is operating.

Fig. 3 is a vertical schematic sectional view along the line III-III of fig. 1.

Fig. 4 is a view partially similar to fig. 3, but in the state shown in fig. 2, and also showing the bar shaft of the striking mechanism.

Fig. 5 to 8 are perspective plan views showing a second embodiment of the release device in a watch with a striking mechanism, similar to the example of fig. 1 to 4, in four successive states of the striking mechanism, fig. 5 showing the rest position.

Detailed Description

Fig. 1 to 4 show those elements of a watch with a striking mechanism, in this case a minute repeater, which contributes to the understanding of the invention. In general, a timepiece movement (not shown) drives the time display device 2 by friction, wherein we can see: a minute wheel 3 provided with minute needles; and a feed mechanism 4 comprising a wheel 5 meshing with the minute wheel 3; and a pinion gear 6 engaged with an hour wheel (not shown).

In conventional manner, the time-setting mechanism 8 comprises a control stem 9 having an intermediate position for winding the movement and at least one extracted position for setting the time, and carrying at its outer end (not shown) a manual control crown. A clutch wheel 10 with face teeth 11 can slide over a square portion 12 of the stem 9. By means of a pull-out 13 cooperating with stem 9 and a rocker 14 cooperating with clutch wheel 10, pull-out 13 and the return spring, the axial movement of stem 9 controls the axial movement of the clutch wheel between a winding position (not shown), in which the clutch wheel cooperates with a conventional intermediate winding wheel 15, and a time-setting position (figures 1 and 2), in which the teeth 11 of the clutch wheel mesh with a first pinion/first intermediate wheel 16 (commonly called clutch wheel) of a time-setting train 17. This train 17 also comprises a set of rotating wheels 18 comprising: an intermediate moving wheel 19, and an intermediate pinion 20 meshed with the moving wheel 5. To allow disengagement in accordance with the principles of the present invention, the intermediate moving wheel 19, which is normally engaged with the first intermediate wheel 16, can be released from the first intermediate wheel 16 to interrupt the kinematic connection achieved by the time-setting train. In the first embodiment shown in fig. 1 to 4, the intermediate moving wheel 19 slides over a non-circular, for example square, portion 22 (fig. 3 and 4) of the spindle of the intermediate pinion 20 and is thus movable in the axial direction. For this purpose, the intermediate wheel 19 has a circular outer groove 23 in which the free end 24 of a flexible, slightly curved strip 25 engages, the base 26 of the strip 25 being fixed and prestressed so that the elasticity of the strip tends to reduce the intermediate wheel 19 to keep it normally in its coupling position, as shown in fig. 3.

The figures only partially show the striking mechanism 30 of the minute repeater. Let us recall that this type of mechanism taps the time indicated visually by the time display device as required, by tapping to indicate hours, quarter-hours and minutes elapsed in a quarter-hour. Typically, the user activates a lever having the effect of spring winding the striking mechanism and causes the striking mechanism to start working. The striking mechanism acquires time-related information from cams (also called snails) connected to the display device 2, namely a quarter cam 31 and a minute cam 32 connected to the minute wheel 3, and an hour cam 33 fixed to a star wheel having twelve branches 34, advancing one step at the end of each hour.

In fig. 1 to 4, the person skilled in the art will recognize the various components of the striking mechanism 30 of the minute repeater, in particular the rack 36, the hour piece 37 pivoted at 38 and provided with a feeler lever 39, the minute piece 40 pivoted at 41 and provided with a feeler lever 42, the quarter-clock piece 43 provided with a feeler lever 44 and a minute pawl 45 (omitted from fig. 2 for clarity of the drawing), and the striking bar shaft 46 having a central axis 47 (fig. 4) for fixing the spring of the striking mechanism. In conventional fashion, the spindle 46 includes a square portion 50 along which there is an hour ratchet 51, a rack and pinion 52, a quarter drive finger 53 associated with a quarter pinion 54, and a retaining nut 55.

In this example, a lifter cam 56 is also mounted on the square portion 50 so that it is rotationally fixed to the spindle 46. The cam 56 has a peripheral profile 57, a portion of its periphery being helical and the remainder of the periphery being circular, against which one end 59 of the lifting rod 60 is pressed by the action of a spring indicated by the arrow R. The lifter 60 has a hub 61 mounted on a pivot 62 so that the lifter cannot vibrate vertically. The other end 63 of the lifting rod is provided with a hemispherical projection 64 against which the elastic band 25 abuts by prestressing in the lowered vertical position. The bottom surface of the strap has a hollow 65 which, in the rest position of the lifting rod 60 and the strap 25, forms a recess for the projection 64, the function of which is to keep the intermediate moving wheel 19 in the coupling position. Due to the inclination of the bottom surface 67 of the strip 25, the strip can be lifted by the movement of the projections 64 in the direction of arrow D in fig. 4, i.e. in the direction of the intermediate moving wheel 19.

In the rest position of striking mechanism 30 shown in fig. 1 and 3, striking bar shaft 46 is at the end of its travel such that end 59 of lifter 60 abuts against the smallest radius portion of cam 56. The lifting lever is thus in the rest position, the belt strip 25 occupies the low position shown in figure 3 and keeps the intermediate moving wheel 19 engaged with the first intermediate wheel 16, so that the time-setting train 17 is in the coupled condition. When the user places the control stem 9 in the pulled-out position to set the time, as in the case of figures 1 and 3, the clutch wheel 10 meshes with the first intermediate wheel 16 and, as in a conventional watch, the manual rotation of the stem 9 will be transmitted to the moving wheel 5 through the time-setting train 17.

When the user pulls the conventional winding bar which starts the operation of minute repeater striking mechanism 30, rack 36 is pushed to pivot in arrow a and rotate spindle 46 in a counterclockwise direction by pinion 52 to wind the striking mechanism spring. This rotation also rotates the lifter cam 56, which helical profile pivots the lifter 60 in the direction of arrow B. Projection 64 is then moved as indicated by arrow D in fig. 4, lifting strap 25 and intermediate moving wheel 19 sufficiently to release intermediate moving wheel 19 from the teeth of first intermediate wheel 16. Thus temporarily interrupting the kinematic connection in the time-setting wheel train 17. If the user rotates the control stem 9 to the pulled-out position for setting the time, as is the case in fig. 2 and 4, the stem 9, the clutch wheel 10 and the first intermediate wheel 16 can rotate without any resistance and without any influence.

When winding the striking work, the rotation of arbour 46 and cam 56 occurs by less than one revolution and stops when hour feeler lever 39 abuts against hour cam 33, and hour piece 37 is pushed by an edge 68 of rack 36. The rotation first comprises an initial angle which must enable the hour feeler lever 39 to pass the minimum clearance E existing between its rest position and the shoulder 66 with the maximum radius of the hour cam 33. Usually, the quarter-hour feeler lever 44 and the minute feeler lever 42 are only actuated after this, so that the stroke of the hour feeler lever 39 during said initial angle of spindle rotation represents to some extent the initial idle stroke E. Said initial angle is thus only required to cover at least a helical portion of the profile of the lifting lever cam 56, thus ensuring that the motion work wheel is completely disengaged before the first contact between one of the feeler levers and one of the cams 31, 32 and 33 connected to the time display device 2. Only after this first contact, any sufficient rotation of the minute wheel 3 may cause damage under the influence of an unintentional time-setting operation.

As soon as the striking work is released, the spindle 46 and the cam 56 rotate clockwise (according to the views of fig. 1 and 2) under the action of the barrel spring. The return movement of the lifting rod 60 by means of the action of the spring R only starts at the end of the strike once the end 50 of the rod (which seems to be wrong in the original text, should be 59) has moved over the circular part of the profile of the cam 56 and is located in the spiral part. The feeler lever then comes out of contact with the cams 31, 32 and 33. Thus, the time-setting gear train 17 can be returned to the connected state only after the striking mechanism has finished operating.

The above arrangement therefore eliminates any risk of interference and damage in the event of the user rotating, even unintentionally, the crown of the control stem 9 when the striking work has been driven.

Fig. 5 to 8 show a second embodiment of the disengagement means, which moves laterally instead of axially as the intermediate moving wheel 19 described above. The dotting mechanism may be the same as the previous example and is not shown, except for dotting bar shaft 46, which has a square portion 50 of dotting bar shaft 46 with a lifter cam 56. The time display device is also unchanged, wherein only the set of moving wheels 4 comprising the moving wheel 5 is visible in fig. 5. The time-setting mechanism 8 is also similar to the previous example, with elements 9 to 17, except that the disengagement means is laterally moved. To this end, the uncoupling device comprises a rotating intermediate wheel group 70 carried by a moving bar 71 and comprising an intermediate moving wheel 72 and an intermediate pinion 73 permanently meshed with the moving wheel 5. To allow disengagement according to the principles of the present invention, the intermediate moving wheel 72, normally engaged with the first intermediate wheel 16, can be released laterally by pivoting the lever 71 about its pivot 74, thus interrupting the kinematic connection formed by the time-setting train.

The disengagement control device includes: a lifting lever 76 mounted on a pivot 77 and provided with a beak 78, a spring 80 elastically abutting on a projection 81 of the lifting lever, an intermediate lever 82 mounted on a pivot 83, and a motion work peg 84 formed by a lever mounted on a pivot 85. The function of the spring 80 is to keep the beak 78 against the peripheral profile of the cam 56. The first arm of the intermediate lever 82 has an L-shaped groove 86, and the pin 87 of the lift lever 76 is engaged in the groove 86 and is capable of circulating motion. The other arm of the lever 82 is provided with a pin 88 which engages in an oval hollow 89 in the lever 71. The first arm of the peg 84 includes an oval hollow 90 that receives a pin 91 of the lifter bar 76. The other arm of the peg 84 comprises a pin 92 that can move cyclically in a hole 93 of the rod 71. The hole has a narrow bottom 94 (see fig. 8) directed towards the pivot 74 of the lever so that the lever 71 is prevented from pivoting when the pin 92 is located in the narrow section.

As in the previous example, in the rest position of the striking mechanism (fig. 5), the striking work bar shaft 46 is at the end of travel, so that beak 78 of lifting lever 76 abuts against the portion of minimum radius of cam 56. In this rest position, the levers 82 and 71 occupy the position shown in fig. 5 and keep the intermediate moving wheel 72 engaged with the first intermediate wheel 16, whereby the time-setting wheel train 17 is in a connected state. When the user pulls out the control stem 9 and rotates it to set the time, the clutch wheel 10 meshes with the first intermediate wheel 16 and the rotation of the stem 9 is transmitted to the feed mechanism wheel 5 via the intermediate wheel set 70.

Fig. 6 shows the state of the striking work during winding. When the user pulls out the winding rod that will start the striking mechanism, the spindle 46 is caused to rotate anticlockwise to wind up the striking spring as explained in the previous example. This rotation also causes the lifter lever cam 56 to rotate and the helical profile portion 95 of the cam 56 pivots the lifter lever 76 in the direction of arrow B. The bolt 84 is then pivoted as indicated by the arrow in figure 6 so that the pin 92 of the bolt disengages the narrow portion 94 of the hole 93 to unlock the pivoting of the lever 71. This pivoting occurs in the disengaged condition shown in fig. 7: once pin 87 clears the elbow of groove 86, pivoting of levers 82 and 71 as indicated by the arrows moves intermediate moving wheel 72 laterally so that intermediate moving wheel 72 is released from the teeth of first intermediate wheel 16. The kinematic connection in the time-setting wheel train 17 is thus temporarily interrupted. If the user rotates the control stem 9 in the pulled-out position to set the time, the stem 9, the clutch wheel 10 and the first intermediate wheel 16 rotate without any resistance and without any effect. In this condition, the beak 78 of the lifting lever remains in abutment against the rounded portion 96 of the profile of the cam 56, so that the position of the device does not change when the spindle 46 rotates in the clockwise direction during dotting.

As shown in fig. 8, once the beak 78 of the lifting rod has completed its movement at the circular portion 96 of the cam 56 and descends again along the helical portion 95, the return movement of the lifting rod 76 under the action of the spring 80 starts only after the end of the strike. Due to the movement of pin 87 in groove 86, levers 82 and 71 pivot and intermediate moving wheel 72 returns into engagement with first intermediate wheel 16, following which the movement of peg 84 returns its pin 92 to narrow portion 94 of hole 93 to lock lever 71 in the connected position. The time of the watch can be set again by means of the control stem 9.

Of course, the connection and disconnection functions provided by the present invention may be performed by devices other than those shown in the drawings. For example, in the first embodiment, the intermediate moving wheel 19 can rotate on a cylindrical portion of the spindle of the intermediate wheel 20 instead of the square portion 22 and be connected with the intermediate wheel 20 via its axial movement, either positively (positively) or by friction, while remaining constantly engaged with the first intermediate wheel 16. In a second embodiment, the peg 84 may be omitted and the intermediate rod 82 may be replaced by another type of connection, such as a connecting rod.

Furthermore, although the exemplary embodiments described herein relate to a minute repeater, the principles of the present invention are applicable without any limitation to other types of timepiece having a striking work including a time-setting train. For example, in a watch with an automatic striking work, it is not possible to select the striking bar shaft as the active part for driving the disengaging device according to the invention, since the amplitude of rotation of the arbour is variable. Another movement must therefore be selected, which moves at the beginning of the striking mechanism operation, for example the chronograph in a singing watch (see 43 in fig. 1).

Claims (11)

1. A timepiece, comprising: a striking mechanism (30), a time display device (2) driven by the timepiece movement, and a time-setting mechanism (8) comprising a time-setting wheel train (17) connected to the display device, a manual control stem (9), and a clutch wheel (10) driven in rotation by said stem and able to slide thereon to mesh with a first intermediate wheel (16) of the time-setting wheel train, so as to transmit the rotation of the clutch wheel to the time display device,

characterized by a disengagement means (19, 25; 71, 72) and disengagement control means (56; 60; 56, 76, 82, 84), which disengagement means are inserted into the time-setting train (17) and are arranged in such a way that: -the disengagement means, when actuated, cut off the transmission of the rotary motion of said first intermediate wheel (16) to the time display device (2); the trip control means is operated by a movable portion (46) of the striking mechanism (30) to actuate the trip means when the striking mechanism is operated.

2. Chronograph according to claim 1, characterized in that the uncoupling device comprises an intermediate moving wheel (19, 72) in the time-setting train (17), the uncoupling control device moving said intermediate moving wheel between a coupling position, in which the intermediate moving wheel is engaged with at least one element (16) of the time-setting train, and an uncoupling position, in which the intermediate moving wheel is released from said element (16), the uncoupling device further comprising an elastic element (25, 80) having the effect of keeping the intermediate moving wheel (19) in the coupling position of said wheel.

3. Chronograph according to claim 2, characterized in that the intermediate moving wheel (19) moves in axial direction.

4. Chronograph according to claim 3, characterized in that the intermediate movement wheel (19) is slidingly mounted on a non-circular portion (22) of the arbour of the other element (20) of the time-setting train (17).

5. Chronograph according to claim 3, characterized in that the elastic element (25) is a flexible strip with a fixed base (26), with one end (24) engaged in a groove (23) of the intermediate movement wheel (19) and an inclined surface (67) between the base and the end.

6. Chronograph according to claim 1, characterized in that the disengagement control means comprise: a cam (56) fixed to said movable part (46) of the striking mechanism, and a lifting lever (60, 76) cooperating with said cam (56) and with the disengaging means.

7. Chronograph according to claim 5, characterized in that the disengagement control means comprise; a cam (56) fixed to said movable part (46) of the striking mechanism, and a lifting lever (60, 76) cooperating with said cam (56) and with disengaging means, the lifting lever (60) comprising a projection (64) against which an inclined surface (67) of said flexible strip (25) permanently abuts by prestressing.

8. Chronograph according to claim 2, characterized in that the disengagement control means comprise: a cam (56) fixed to said movable part (46) of the striking mechanism, and a lifting lever (60, 76) cooperating with said cam (56) and with disengaging means, and an intermediate movement wheel (72) movable in a radial direction and carried by a rod (71) connected to the lifting lever (76).

9. Chronograph according to claim 8, characterized in that the lever (71) is connected to the lifting lever (76) by a first element (82) and a pin (84), the first element (82) causing the lever movement, the pin (84) being able to lock the lever in the connecting position of the intermediate movement wheel (72).

10. Chronograph according to claim 6, characterized in that the striking mechanism (30) is a minute repeater mechanism and the active part integral with the cam (56) is the striking bar shaft (46).

11. Chronograph according to claim 10, characterized in that the peripheral profile (57) of the cam (56) comprises a spiral portion (95) cooperating with the lifting rod, followed by a circular portion (96), said spiral portion extending over an angle smaller than the initial angle of rotation of the striking-bar shaft (46), said initial angle producing an initial idle travel (E) of the first feeler-lever (39) of the striking mechanism.