PERCENTAGE MECHANISM

Description

Technical field

[0001] The present invention relates to the field of watchmaking. It relates more particularly to a minute repeater or grand sonnerie type striking mechanism. This type of mechanism allows, at the user's request or in passing respectively, to produce a strike giving information allowing the current time to be coded audibly, thanks to feelers which will "read" the time on cams, and hammers which strike gongs according to a number of strokes which identify the hours, quarters and minutes. State of the art

[0002] Striking watches are among the most complex and difficult complications to produce, particularly due to the large number of parts that need to be made and assembled in a small space. Although they have been known for a long time, initially allowing people to tell the time in the dark, the widespread use of wristwatches has led to a miniaturization of the parts, which means that striking watches are still very exclusive today.

[0003] Also, most brands that offer this type of mechanism implement traditional mechanisms, which have proven themselves, by optimizing the sound quality, by playing on the timbres or the casing. It is indeed difficult to have quality sounds, clear and audible, with a small box. It is rare to completely question the architecture of the repeater mechanism itself.

[0004] For example, document EP1429214 describes a traditional repeater mechanism. When triggered, a user operates a winding lever, by which he winds a striking barrel and simultaneously drives a feeler which reads the hour information on an hour cam. An hour striking part is actuated simultaneously and is positioned opposite a striking lever, with ratchet teeth to strike the hours. In doing so, the quarter and minute striking parts fall until their feeler rests on their respective cam, the striking parts also being provided with ratchet teeth to strike the quarters and minutes respectively.

[0005] The striking barrel, armed when triggered, then drives the hour striking part, as well as a drive finger, which in turn drives the quarter striking part. A ratchet system secures the quarter striking part and the minute striking part. As they move under the action of the striking barrel, the striking parts activate their respective hammers, a number of times corresponding to the number of teeth which, when the striking parts fell, passed the hammer lifts, this number of teeth being defined by the position of the respective cams.

[0006] You can refer to the aforementioned document for details on the operation of a traditional mechanism.

[0007] The aim of the present invention is to propose a new ringing architecture, which is particularly compact and which also offers optimized torque transmissions between the different mobiles. Disclosure of the invention

[0008] More specifically, the invention relates to a striking mechanism comprising, mounted coaxially on the same shaft, a striking spring, one end of which is secured to the shaft and another end of which is secured to a reference frame, and arranged to transmit a torque to the shaft when it is wound, an hour striking part secured to the shaft, a quarter striking part, pivoted on the shaft and intended to be driven by the hour striking part, a minute striking part, pivoted on the shaft and intended to be driven by the quarter striking part.

[0009] The striking mechanism further comprising, on the one hand, disengageable connecting means between the quarter striking part and the minute striking part, capable of evolving between a disengaged state in which the quarter and minute striking parts are free relative to each other, and an engaged state in which the quarter and minute striking parts are integral in rotation around said shaft, and on the other hand, a control member for switching the disengageable connecting means from one state to another.

[0010] The proposed mechanism is thus particularly compact, and the striking parts receive the same torque, in an extremely direct manner, which promotes a regular sound between the different parts, and of quality.

[0011] According to a preferred embodiment, the striking spring is arranged in a recess made in an element of the frame on which said shaft pivots.

[0012] To drive the quarter piece, the hour striking piece advantageously includes a projecting member located in the plane of the quarter striking piece.

[0013] According to a preferred embodiment, the mechanism comprises a trigger lever, intended to be actuated by a user, carrying: a feeler pivotally mounted on said lever, between two extreme positions, and a cam, bearing against the feeler and capable of cooperating with a locking lever of the quarter striking part.

[0014] This system provides an All or Nothing function, which ensures that the striking barrel is sufficiently armed to complete a striking cycle.

[0015] These two extreme positions are defined by a pin attached to the lever, housed in an opening made in the sensor.

[0016] For driving the minute striking part, the disengageable connecting means can advantageously comprise: a minute hook pivotally mounted on the quarter piece, a toothing integral with the minute piece, arranged to cooperate with the minute hook, a flange freely mounted on the shaft and essentially comprising two portions of different radii, concentric with the shaft, a first portion whose radius is less than the radius of the tops of the second toothing, and a second portion whose radius is greater than the radius of the tops of the second toothing, a spring member for pressing the minute hook against the flange.

[0017] Preferably, the flange is secured to a movable bridge, freely pivoted on the shaft, positioned by adjustment means. This makes it possible to adjust the fall of the minute hook in the teeth secured to the minute part.

[0018] In a preferred embodiment, the adjustment means comprise an eccentric arranged in a fork with which the movable bridge is provided. Brief description of the drawings

[0019] Other details of the invention will appear more clearly on reading the following description, made with reference to the appended drawing in which: there figure 1 illustrates more particularly the parts participating in the triggering of a striking mechanism according to the invention, the figure 2 illustrates the striking mechanism of a striking mechanism according to the invention, the Figures 3 and 4 are respectively top and perspective views, illustrating more particularly the parts participating in the chiming of the hours, the Figures 5 and 6 are perspective views illustrating more particularly the parts participating in the striking of the quarters and minutes, and the figures 7 and 8 illustrate more particularly certain details of the invention. Method of carrying out the invention

[0020] A striking mechanism, here of the repeater type, being complex, the description which follows, with reference to the figures, will present the different components in functional sub-assemblies, in order to simplify reading.

[0021] On the figure 1 , we can observe a trigger lever 10, pivoting on the frame of the movement (not shown) and accessible from outside the case by a user. The trigger lever 10 is integral with a winding rack 102 engaged with a winding pinion 14. The latter is mounted square on a shaft 16, which is the main pivot axis of the mechanism according to the invention.

[0022] The shaft 16 is connected to a striking spring (not visible in the drawing), housed directly in a hollow made in an element of the frame, in this case a bridge 18 ( Fig. 2). More precisely, one end of the striking spring is fixed to the shaft, while the other is secured to the frame. The torque of the spring is thus applied to the shaft, which is rotated by the spring, when it is wound. The shaft 16 also carries a first mobile 20, comprising a unidirectional connection obtained by a ratchet system, between a ratchet 201 secured to the shaft 16, with which cooperates a pawl spring 203, fixed to a plate 205. The plate 205 is connected to a regulator 22 by a striking train 24, which is driven when the striking spring unwinds via the plate 205 with which it meshes. Thanks to the unidirectional connection, the striking train 24 is not driven when the striking spring is wound.

[0023] Fixed on the shaft 16, a 40-hour striking piece (also called the 40-hour piece) with a twelve-tooth ratchet sector, is arranged to cooperate with a hammer lift, not shown, to strike the hours. The number of hours to be struck will depend on the angular position of the 40-hour striking piece, when triggered. As can be seen on the figure 3, this is defined by an hour feeler 104. This hour feeler 104 is pivotally mounted on the axis of the trigger lever 10. It comprises a beak 106 which will read the information relating to the current time on a twelve-step hour snail 42, secured to an hour star 44. The hour feeler 104 is connected to the trigger lever 10 by a pin 108, secured to the lever 10 and passing through an opening 110 in the form of a circular sector formed in the feeler 104 which allows play between these two parts. The hour feeler 104 also comprises a finger 112, the role of which will appear below.

[0024] The trigger lever 10 also carries a cam 114 of particular shape and designated in certain works by the name of bird or devil, and which is part of a system known to those skilled in the art under the name of All or Nothing. It requires the user to fully operate the trigger lever for the complete ringing to take place. The cam 114 is screwed freely onto the lever 10 and comprises a lift 116 on which is held in support by a non-visible spring, a locking lever 46. This presses the cam 114 against the finger 112 by a flank 118 which the cam 114 comprises.

[0025] The locking lever 46 is pivoted on the frame and comprises a latch 462, capable of cooperating with a hook 502 of a quarter-striking part 50, which will be described in detail below. A spring not shown tends to keep the latch 462 of the locking lever 46 engaged with the hook 502.

[0026] Thus, when a user actuates the trigger lever 10, it pivots until the beak 106 comes into contact with the hour snail 42. The striking spring is thus wound and the hour striking part 40 takes an angular position which corresponds to the number of hours to be struck. The user maintaining his pressure, the trigger lever 10 continues its travel, while the feeler 104 remains in position, which causes the rotation of the cam 114, which will pivot the locking lever 46.

[0027] We will now focus on describing the 50 quarter striking piece (also called the 50 quarter piece) and its operation, particularly with reference to the Figure 5 . It is freely pivoted on the shaft 16 and is subjected to the action of a spring 51 ( Fig. 4 ) which tends to rotate the 50 quarter coin clockwise, in reference to the figures 4 And 5. The spring 51 is advantageously of the spiral type, wound around the shaft 16, between the quarter piece and the hour piece. The quarter piece 50 has a series of teeth 504 intended to cooperate with hammer lifts to strike the quarters. In the example illustrated, it is a Westminster type strike, the teeth of the quarter piece are arranged on circular sectors, concentric to the shaft 16, located in different planes, four in this case, to cooperate with four lifts and play the so-called Westminster melody.

[0028] Concentrically to the shaft 16, the quarter piece 50 has a toothing 52, with which the rack 600 of a quarter feeler 60 meshes. The latter pivots on the frame and has a beak 602, arranged to cooperate with a quarter snail 65. It is the spring 51 which exerts a torque which tends to bring the feeler into contact with the snail.

[0029] The 50 quarter piece still has the 502 hook mentioned above. It still has a 510 minute hook ( Fig. 6 ), pivotally mounted on the quarter piece, for example between two ears 512 arranged on the pieces which carry the teeth 504. This minute hook 512 comprises two crampons 514 oriented in the direction of the shaft 16 and it is subject to a spring which tends to bring said crampons 514 closer to the shaft 16.

[0030] To drive the quarter piece 50 during a strike, the hour piece 40 has a pin 402 ( Fig. 4), fixed in the hour part 40. The pin 402 or any other projecting member, is located at least partially in the plane of the quarter part 50, which means that, during the counterclockwise rotation (with reference to the figures) of the hour striking part 40, under the action of the striking spring which relaxes, the quarter part 50 is also driven in this same movement when the pin 402 comes to bear against the edge of the quarter part 50. It will be noted that, given that the hour striking part 10 and that of the quarters 50 are pivoted around the shaft 16, the transmission of torque between the pin 402 and the edge of the quarter part is done without sliding and therefore without loss of energy. The energy of the striking barrel is therefore transmitted almost without loss in the racks.

[0031] For the minutes strike, the mechanism includes a minutes strike piece 100 (also called minutes piece 100). It is also freely pivoted on the shaft 16 and is subject to the action of its spring (not visible in the drawing) which tends to pivot it in a clockwise direction, with reference to figures 4 to 6 This spring is also, advantageously, of the spiral type, arranged between the minute part and a fixed element, in this case linked to the shaft 16. The minute part 100 has a series of fourteen teeth 1002 intended to cooperate with a lift of hammers to strike the minutes.

[0032] Concentric to the shaft 16, the minute part 100 has a toothing 1004, with which the rack 1100 of a minute feeler 110 meshes. The latter pivots in the plate and has a beak 1102, arranged to cooperate with a minute snail 120. It is the spring of the minute part which exerts a torque which tends to bring the beak 1102 into contact with the minute snail 120.

[0033] The minute snail is associated with a surprise mechanism 200, better visible on the Figure 5. This type of mechanism is a safety device connected to the quarter snail 42, to prevent false ringing (counting down) when changing from one quarter to another. The surprise has the function of lengthening, just after the change of quarters and during the first minute, the 0 minute step of the minute snail 120 which is shortened for reasons of safety and space. This prevents the minute beak 1102 from taking information from step 14, while the quarter snail 42 has already advanced and presents its next step to its feeler. For this purpose, the surprise 200 comprises a board having a generally conventional shape, comprising four arms, distributed at 90, ending with a step 2001 located at the level of step 0 of each branch of the minute snail 120.When the strike is triggered, a surprise jumper 122 is activated and, when the surprise is in the angular position corresponding to the first minute of a quarter, it is in the course of the surprise jumper which pushes it and shifts it in relation to the minute snail, to lengthen the 0 step.

[0034] According to an interesting aspect of the construction, the surprise 200 is connected with play to the minute snail 120. The latter comprises a pin 1200, engaged in an opening 2002 in the shape of a circular sector made in the surprise board, so as to allow relative movement between the surprise and the minute snail. Furthermore, the surprise board is elastically connected to the quarter snail. To do this and in an original manner, the surprise comprises a spring 2004, made in one piece with the surprise board and connected by a first of its ends to a branch of said board.

[0035] The board and its spring are advantageously manufactured using microfabrication techniques such as LIGA, or wire electroerosion, for example. The spring 2004 has a succession of meanders, which makes it possible to extend its active length and increase its plastic deformation threshold, which is advantageous given the very small dimensions of the part. Indeed, the spring would otherwise risk plastic deformation. At its other end, the spring is connected to the quarter snail, for example via an eyelet 2006 which it includes and which cooperates with a pin secured to the quarter part.

[0036] Thus, when a strike is triggered during the first minute of a quarter, the surprise jumper 122 for the surprise 200 which then extends the 0 step of the hour snail, by tensioning the spring. When the surprise jumper returns to its rest position, it leaves the surprise 200 free which, under the action of the spring 2004, returns to its initial position relative to the minute snail, with the pin in driving contact with the opening 2002.

[0037] To release the minute piece 100 or to drive it, as will be understood below, the minute piece comprises a second toothing 1006, provided with ratchet teeth, arranged to cooperate with the crampons 514 of the minute hook 510. Having two crampons is advantageous in that it allows the pressures which can be significant to be distributed when the striking barrel is wound.

[0038] This second toothing 1006 comprises fifteen tooth bases, each corresponding to a minute of the quarter, and participating in determining the travel of the minute piece 100. In order to control the position of the minute hook 510 and determine whether it is engaged in the second toothing 1006 or held out of reach, the mechanism comprises a flange 130 mounted freely on the shaft 16 and located in the plane of the minute hook 510 (see figures 7 and 8 ). As will be described later, the flange 130 is held in a determined angular position and the shaft 16 pivots freely relative to it.

[0039] This flange 130 essentially comprises two portions of different radii, concentric with the shaft 16, a first portion 1302 whose radius is less than the radius of the apexes of the second toothing 1006, and a second portion 1304 whose radius is greater than the radius of the apexes of the second toothing 1006. Thus, when the minute hook 510 is located with its two spikes opposite the first portion 1302, it enters the second toothing 1006, making the striking parts of the minutes 100 and the quarters 50 integral, while, when at least one spike of the minute hook 510 is located opposite the second portion 1304, the minute hook 510 remains in contact with the flange 130, leaving the striking part of the minutes 100 free with respect to that of the quarters 50. Between the two portions 1302 and 1304, an inclined plane is provided allowing the hook to pass easily from one portion to another.

[0040] The minute hook 510, the teeth 1006, the flange 130 and the spring member which presses the minute hook against the flange form disengageable connecting means between the quarter striking part and the minute striking part, capable of evolving between a disengaged state in which the quarter and minute striking parts are free relative to each other, and an engaged state in which the quarter and minute striking parts are integral in rotation around said shaft,

[0041] Thus, at rest, the minute hook 510 is located opposite the first portion 1302 of the flange 130 and is engaged in the toothing 1006 and the quarter 50 and minute 100 striking parts are coupled and rotationally fixed. When a strike is triggered, when the quarter part 50 falls, the minute striking part 100 is therefore also driven, by the quarter part 50, under the action of the spring 51 and by its own spring, until the moment when the minute hook 510 comes to bear against the flange 130, opposite the second portion 1304. The minute part 100 is then detached from the quarter part 50 and can fall onto its snail 120, under the effect of its own spring.When then, the quarter piece 50 is driven by the hour piece 40, to strike the quarters, the minute hook 510 which it carries passes from its support on the flange 130, to a position engaged in the second toothing 1006, passing from a position opposite the second portion 1304 to a position opposite the first portion 1302. The relative position of the minute piece 100 has in the meantime changed, according to the position of the minute cam, and the quarter piece 50 can then drive the minute piece 100 to strike the minutes.

[0042] If this type of operation is effective, it may be useful to be able to precisely adjust the moment when the minute hook 510 engages with the second toothing 1006, in order to ensure that the minute hook 510 takes the toothing base corresponding to the number of minutes to be struck. Indeed, with the relative speeds between the minute hook and the rotations of the minute pieces 100 and quarter pieces 50, an adjustment may be necessary.

[0043] Thus, as shown in the figure 8, the flange 130 is integral with a movable bridge 150, freely pivoted on the shaft 16, but whose travel is limited by two windows 152, concentric with the shaft 16 and in which guide screws 154 are arranged. The movable bridge 150 comprises an arm terminated by a fork 156, in which an eccentric 158 is placed. The latter makes it possible to adjust the angular position of the movable bridge 150 by a few degrees, in order to adjust the engagement of the minute hook 510 in the second toothing 1006. Thus, by adjusting the eccentric 158, it is possible to adjust the angular position of the flange 130 and therefore to precisely adjust the moment when the minute hook engages with the toothing.

[0044] This description has been given as a non-limiting illustration of the invention. Those skilled in the art will be able to derive a certain number of variants, the scope of protection being determined by the claims.

Claims

1. Striking mechanism comprising, coaxially mounted on a same shaft (16), - a striking spring, one end of which is integral with the shaft and another end of which is integral with a reference frame, and arranged to transmit a torque to the shaft when it is loaded, - an hour striking cam (40) integral with the shaft, - a quarter striking cam (50), pivoted on the shaft and designed to be driven by the hour striking cam, - a minute striking cam (100), pivoted on the shaft and designed to be driven by the quarter striking cam, the striking mechanism further comprising disengageable connecting means between the quarter striking cam and the minute striking cam, capable of changing between a disengaged state in which the quarter striking and minute striking cams are free relative to one another, and an engaged state in which the quarter striking and minute striking cams rotate together about said shaft, a control member (130) for switching the disengageable connecting means from one state to another.

2. Striking mechanism as claimed in claim 1, characterized in that the striking spring is arranged in a recess formed in an element of the frame on which said shaft is pivoted.

3. Mechanism according to one of the preceding claims, characterized in that the hour striking cam (40) comprises a projecting member (402) located in the plane of the quarter striking cam (50), to drive it.

4. Striking mechanism according to one of the preceding claims, characterized in that it comprises a release lever (10), intended to be actuated by a user, carrying: - a feeler (104) pivotally mounted on said lever, between two extreme positions, and - a cam (114), bearing against the feeler (104) and able to cooperate with a locking rocker (46) of the quarter striking cam (50).

5. Ringing mechanism according to claim 4, characterized in that said two extreme positions are defined by a pin (108) integral with the release lever (10), housed in an opening (110) provided in the feeler.

6. Mechanism according to one of the preceding claims, characterized in that the disengageable connecting means comprises: - a minute hook (510) pivotally mounted on the quarter striking cam, - a toothing (1006) integral with the minute striking cam, arranged to cooperate with the minute hook, - a flange (130) freely mounted on the shaft and essentially comprising two portions of different radii, concentric with the shaft (16), a first portion (1302) whose radius is less than the radius of the vertices of the second toothing, and a second portion (1304) whose radius is greater than the radius of the vertices of the second toothing (1006), - a spring member for pressing the minute hook against the flange.

7. Mechanism according to the preceding claim, characterized in that the flange (130) is integral with a movable bridge (150), freely pivoted on the shaft (16), positioned by adjustment means.

8. Mechanism according to claim 6, characterized in that the adjustment means comprise an eccentric (158) arranged in a fork (156) with which the movable bridge (150) is provided.