Patent Application
20050157594
The present invention relates to control mechanisms of a timepiece of the type comprising:
More particularly, the invention concerns the time-setting mechanisms for which the control rod is a time-setting rod and the retaining plate is a pull-out.
In these timepieces, control is via a translation and rotation movement of the rod, via a crown wheel with which it is fitted at its outer end. According to the axial position of the rod, it is possible, by rotating it, to correct one or other of the information items displayed, usually the date in the first pulled out position and the time in the second.
So that the rod can perform its function in satisfactory conditions, its movement must be limited axially. Accordingly, the pull-out is furnished with a stud engaged in the groove of the rod.
In most mechanisms, the pull-out is on the dial side of the watch. A screw or a pin is accessible from the back side so that the pull-out can be pushed in such a way that the stud comes out of the groove during the operation to push in and pull out the rod. This operation is tricky, because it requires two simultaneous movements, both the movement of the pull-out and the pulling out of the rod.
A gear mounted on the time-setting rod is kinematically connected, via an angle transmission, to the time-setting movement or to the date-correction movement, according to the position of the rod. The moving of the gear against the first angle transmission is provided by a mechanism consisting of the pull-out and a lever. The pull-out interacts with the lever at its end opposite the end supporting the stud. The lever then moves the gear, by pressing on one or other of the sides of a groove made in the thickness of the gear. This mechanism is well known to those skilled in the art and is, for example, described in the book on the theory of clockmaking by Chs-A Reymondin et al, page 40 (Fédération des Ecoles Techniques de Suisse, 1998, ISBN 2-940025).
The patent CH 8 819 describes a time-setting mechanism in which the pull-out is on the back side and its pull-out stud is replaced by a pivot screw, which thus prevents any translation movement of the rod. It is therefore necessary to loosen the screw to release the rod. This device has at least two major disadvantages. First of all, the lever into which the screw passes must be of sufficient thickness that a tapping can be made in it capable of firmly retaining the screw. This increases the thickness of the movement by the same amount. Furthermore, it is never guaranteed that a tightened screw will not loosen under the effect of the vibrations.
The present invention proposes a solution making it easier to pull out and push in the time-setting rod without having to simultaneously push the pull-out and avoiding the disadvantages of the solution proposed in the abovementioned patent.
More precisely, the invention relates to a control mechanism for timepiece of the type comprising a frame furnished with two parallel faces defining a reference plane, one of which is intended to support a dial and the other is opposite the back. The mechanism also comprises, secured to this frame:
The retaining plate is mounted on the back side and supports the locking piece, mounted so as to rotate about a second axis BB′ perpendicular to the reference plane. It is arranged such that it is capable of occupying a first position, called the locking position, in which the translation movement of the rod is limited by the engagement of the locking piece in the groove and a second position, called the unlocking position, in which said piece is no longer engaged in the groove, thus allowing the rod to be pushed in on the frame or pulled out.
According to the invention, the locking piece comprises:
The following description refers to a control mechanism consisting of a time-setting rod that can terminate in a gear which is secured to it in rotation and in translation and to a retaining plate consisting of a pull-out that can move in translation.
It is advantageous that the locking piece comprises positioning means ensuring that it is retained in the locked and unlocked positions. They are formed by a frictional engagement of a part of the locking piece on the retaining plate and, in a particularly advantageous embodiment, by the wings which extend on the sides of the groove beyond its bottom, and whose free end espouses, in the locked position, the contour of the internal diameter d, in such a way as to define a notch engagement.
The invention will be better understood on reading the following description made with reference to the appended drawing, in which the
a shows a portion of watch movement, and more particularly at 10 a frame, for example a mainplate, furnished with two parallel faces defining a reference plane, one of which is intended to support a dial and the other is facing the back. A time-setting rod 12, furnished with an annular groove 14 possessing a width l, an external diameter D and an internal diameter d, is mounted so as move translationally and rotationally in the frame 10, along a first axis (AA′) included in the reference plane. The end of the rod 12 inserted into the mechanism of the watch consists of a tooth gear 16, interacting with a time-setting angle transmission which is not shown in the drawing and which pivots on a stud 18.
Now, with reference to
The pull-out 20 is provided with holes 24 which engage with the studs attached to the frame, not shown in the drawing, in order to guide it during its translational movements.
The locking piece 22 is arranged so as to be able to occupy two positions, either the one called the locking position, in which the rod 12 and the pull-out 20 are integral in translation and the other, called the unlocking position in which it is possible to pull out the rod or push it in.
The piece 22 comprises a first mid-part 26, of general cylindrical shape, of which a first portion 28 is in frictional engagement in the pull-out 20 in order to allow its rotation along a second axis BB′, that passes, in dummy fashion, vertically through the center of the groove 14 when the rod is in place and of which a second portion 30, of greater diameter, is engaged in a countersinking 32 formed in the thickness of the pull-out 20 and pressing against its bottom, in order to axially position the piece 22.
A second, upper, part 34 of the locking piece 22 is furnished with a slot 36 passing through it radially so that it can allow the engagement of a flat screwdriver in order to rotate the piece 22.
Finally, the piece 22 terminates, on the side of the time-setting rod 10, in a third part 38 which comprises two wings 40, separated by an opening 42 passing through it horizontally, and placed symmetrically relative to a vertical plane which, in the unlocked position, includes the axis AA′. As shown in
The locking piece 22 is therefore mobile in rotation along the axis BB′. The wings 40 of the part 38 of the piece 22 are arranged such that in locked position, visible in
A quarter turn rotation of the locking piece 22 is used to move to the second unlocked position, visible in
Therefore, a locking piece has thus been produced which can be used to move, without dismantling pieces, from a locked position to an unlocked position, these two positions being stable. In locked position the time-setting rod and the pull-out are perfectly integral in translation, while in the unlocked position, the rod can easily be pulled out or pushed in.
In one variant, the wings 40, in the locked position, extend on the sides of the groove 14, beyond its bottom, their free end espousing the contour of the internal diameter d to ensure that the locking position is maintained with a notch.
To pass over the locking notch, the applied rotation force must overcome the forces of elastic resistance exerted by the rod 12 and by the pull-out 20. The wings 40 press on the bottom of the groove 14 and slightly move the rod 12 and the pull-out 20, in order to allow their passage and the transition to the unlocked position. In this case, the mid-part 26 can be mounted free onto the pull-out 20, the position of the locking piece 22 being ensured by the notch.
The description that has just been made applies to a time-setting rod, but it goes without saying that the invention can very well be adapted to any control rod and even to a pushbutton likely to be operated by a movement in translation. In this case, the retaining plate of the locking piece may be fixed. It may also involve a flip-flop lever controlled by the pushbutton and forming part, for example, of a chronograph mechanism.
| Number | Date | Country | Kind |
|---|---|---|---|
| 024052813 | Apr 2002 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CH03/00197 | 3/26/2003 | WO |
