Other features and advantages of the present invention will appear more clearly upon reading the following detailed description, made with reference to the annexed drawings, given by way of non-limiting example and in which:
In the annexed Figures, when trains are shown, the teeth of the trains are not systematically shown, in order to simplify the drawings and facilitate comprehension of the drawings.
The repeater striking mechanism 18 of wristwatch 10 according to the invention is for example of the grand strike type, i.e. it is capable of striking the hours and the quarters, and it is either released automatically or upon demand, via the effect of manual intervention M2.
Motion work 12 is driven in rotation by a barrel 20, which is shown in
In the following description, a vertical orientation along axis A1 of drive arbour 26 of barrel 20 will be used in a non-limiting manner.
Spring 24 is a strip in the shape of a coil wound around drive arbour 26. Drum 22 includes a recess 32 in its inner axial wall for securing a second end 34 of spring 24.
Drum 22 comprises an external toothing 36 which meshes with an intermediate motion work pinion 37 secured in rotation with intermediate motion work wheel 39 (visible in
A winding ratchet 38 coaxial to barrel 20 is mounted on the top axial end 40 of drive arbour 26 via a square 42, so that winding ratchet 38 is secured to drive arbour 26 in rotation.
A winding member 44, which can be controlled by a manual action M1 on a winding stem (not shown), is provided for winding barrel spring 24, during a winding phase. Winding member 44 is formed here by a pinion that meshes with winding ratchet 38 so as to drive winding ratchet 38 in rotation in the winding direction of spring 24, in the clockwise direction in
According to the teaching of the invention, winding ratchet 38 drives strike train 16 in rotation via an intermediate wheel set 45 whose axis of rotation A2 is shifted relative to the axis A1 of barrel 20. Intermediate wheel set 45 is provided with a click device 47 for uncoupling winding ratchet 38 relative to strike train 16 during the winding phase of spring 24.
Intermediate wheel set 45 comprises an intermediate wheel 46, which is connected in rotation to ratchet wheel 48. Ratchet wheel 48 is connected in rotation, in the let down direction of barrel spring 24, via two clicks 50, 52, to an intermediate pinion 54 meshing with strike train 16. Click device 47 is formed here by ratchet wheel 48, clicks 50, 52 and intermediate pinion 54.
When release member 19 is activated, whether automatically or by a manual intervention M2, it releases strike train 16, which is driven in rotation via the effect of barrel spring 24 letting down, spring 24 then unwinding in the direction of let down causing winding ratchet 38 to rotate, here in the anti-clockwise direction. Winding ratchet 38 is thus retained in the direction of let down of barrel spring 24 by strike train 16, which remains locked until it has been released by release member 19.
According to the embodiment shown here, winding ratchet 38 meshes with a main setting wheel 56, which meshes with intermediate wheel 46. Main setting wheel 56 and intermediate wheel 46 extend in the same plane as winding ratchet 38.
According to an advantageous embodiment, illustrated in particular in
Each click 50, 52 is pivotably mounted about a click arbour 62, 64, which is secured in the top transverse face 66 of intermediate pinion 54. The two click arbours 62, 64 are diametrically opposite here. Each click 50, 52 is drawn towards the teeth of ratchet wheel 48 by an associated resilient return strip 68, 70.
Advantageously, an inversion wheel 72 is inserted axially between ratchet wheel 48 and intermediate pinion 54. Inversion wheel 72 comprises two oblong holes 74, 76 through which the two click arbours 62, 64 respectively extend. Resilient strips 68, 70 are fixed here to the top transverse face 78 of inversion wheel 72.
Inversion wheel 72 is connected in rotation to intermediate pinion 54 by the abutment of click arbours 62, 64 against the end edge of the associate hole 74, 76. Holes 74, 76 allow a determined angular clearance via the circumferential length of holes 74, 76, between inversion wheel 72 and intermediate pinion 54.
If inversion wheel 72 pivots relative to intermediate pinion 54, clicks 62, 64 are raised because of the movement of the abutting end 80 of each resilient strip 68, 70 on the opposite side to the pivoting axis of the associated click 62, 64, strips 68, 70 no longer drawing clicks 62, 64 towards ratchet wheel 48.
The purpose of inversion wheel 72 is to facilitate maintenance operations for timepiece 10 by enabling clicks 50, 52 to be raised to let down spring 24, as will be explained hereinafter.
According to another advantageous feature of the invention, an auxiliary setting wheel 82 meshes with intermediate pinion 54. Auxiliary setting wheel 82 is drawn in rotation in the drive direction of strike train 16, i.e. in the direction of let down of barrel spring 24, so as to maintain a locking torque on intermediate pinion 54 during the winding phase of barrel spring 24.
The operation of timepiece 10 according to the invention will now be explained.
In a neutral situation, i.e. in the absence of striking or a winding operation, timepiece 10 indicates the current time and striking mechanism 18 is locked in a position ready to release a strike. Motion work 12 is driven in rotation by barrel gong 22 which is rotating here in the clockwise direction, via the effect of barrel spring 24, which is unwinding.
In this neutral situation, barrel spring 24 is unwinding in only one direction since, on the side of its first end 28, it is stationary, winding ratchet 38 being held in a fixed angular position by strike train 16 and striking mechanism 18.
During a striking phase, release member 19 releases striking mechanism 18, which releases strike train 16, which is driven in rotation by winding ratchet 38, which then rotates with barrel arbour 30, here in the anti-clockwise direction.
During the striking phase, barrel spring 24 unwinds via both ends since its first end 28 is connected in rotation to winding ratchet 38, whereas its second end 34 continues to move with barrel 22 to drive motion work 12 and to continue to display the current time.
During a winding phase, winding member 44 meshes with winding ratchet 38 to drive it in rotation, here in the clockwise direction, and thus to wind barrel spring 24.
The rotation of winding ratchet 38 causes intermediate wheel 46 to rotate, via main setting wheel 56, in the opposite direction relative to the striking phase, here in the clockwise direction. Ratchet wheel 48 rotates with intermediate wheel 46 causing clicks 50, 52 to rise, against resilient strips 68, 70, owing to its wolf teeth 49, such that intermediate pinion 54 remains substantially stationary angularly.
During the winding phase, auxiliary setting wheel 82 maintains a locking torque on intermediate pinion 54, which compensates for angular plays and thus, because of the release of the torque exerted by winding ratchet 38 on strike train 16 in the direction of release of the striking mechanism, prevents the elements of striking mechanism 18 from moving, which would be liable to cause an inadvertent release of the striking mechanism.
During a maintenance operation, it may be necessary to let barrel spring 24 down without having to release a series of strikes, particularly to relieve striking mechanism 18. By driving inversion wheel 72 in rotation relative to intermediate pinion 54, for example by means of a tool or a rack fitted to timepiece 10 and meshing with teeth of inversion wheel 72, in the anti-clockwise direction looking at
The present invention has been described here with reference to a timepiece 10 fitted with a grand strike mechanism. Of course, the invention applies to any timepiece comprising a strike train and a motion work, and wherein the energy for the striking mechanism is provided by a barrel, particularly timepieces having a striking mechanism with programmed release (alarm function) and small strike timepieces.
Number | Date | Country | Kind |
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06112532.4 | Apr 2006 | EP | regional |
This application claims priority from European Patent Application No. 06112532.4, filed Apr. 12, 2006, the entire disclosure of which is incorporated herein by reference.