CH682201B5 - Movement automatic chronograph. - Google Patents

Abstract

The watch comprises an analogue mechanism with a balance wheel and coil spring. A pinion (24) is arranged at the centre of the movement, making one turn per house, and is linked with a drive train comprising wheels (29,30,33,34). This drives the hands for displaying the time, rotating about an eccentric axis. At the centre of the movement there is only one chronograph hand, and a hand which can be reset, which is controlled by a pushbutton (12) with a resetting mechanism (41,43,44,50,51,53,59). The drive train and the resetting mechanism are on the side of the movement facing the dial. USE/ADVANTAGE - The watch combines chronograph functions with automatic rewinding operating by falling weight.

Description

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Description

The present invention relates to a split-seconds chronograph movement, in particular for a wristwatch. It relates more particularly to an analog mechanical movement with a balance-spring indicating the time and the time interval measured by means of hands, and comprising an automatic winding device by oscillating weight.

A movement of this type is used in the automatic split-seconds chronograph watch marketed by Blancpain (Le Brassus, Switzerland), the chronograph hand, the split-seconds hand and the hands for the pivoting time display in this part around the same central axis of revolution. The movement of this chronograph schematically comprises three constituent parts, each fulfilling a specific function. These parts, superimposed on each other and dividing the movement approximately in three parallel sections, are arranged perpendicular to the central axis of revolution. The first part, the most important, includes the clockwork movement with the barrel, the chronograph mechanism, the cogs for driving the different hands, and the devices for setting the watch time and controlling the chronograph. The second part, arranged between the two other parts, includes the catch-up mechanism, which acts on the split-seconds hand of the chronograph. Finally the third part contains the automatic winding mechanism, and it supports the oscillating weight. This construction, if it makes it possible to obtain a movement of reduced height, presents on the other hand great difficulties of realization because the rotation of the oscillating mass must be transmitted to the barrel through the take-up mechanism. For this reason, the production of such a movement is complex and costly, which makes it suitable for watches situated in a range of high prices.

The object of the present invention is to present an automatic split-seconds chronograph movement which is simpler to produce and less expensive to produce.

To achieve this objective, the movement according to the invention, comprising two substantially planar and parallel main faces, one of the faces supporting the watch face, a clockwork mechanism driving in rotation about an axis of revolution, arranged perpendicular to the main faces and passing through the center of the movement, a mobile capable of indicating the time, an analog time display device with hands, time setting means acting on the clockwork mechanism, a chronograph mechanism for measuring a time interval driving a chronograph hand and a retracting hand around the axis of revolution to indicate and store the duration of the time interval, means for controlling the chronograph mechanism, a take-up mechanism acting on the take-up needle in response to an action on a member of the control means, and an automatic winding mechanism by oscil mass lante disposed on the other main face, is mainly remarkable in that it further comprises a deflection mechanism disposed on the main face of the movement supporting the dial to drive the hands of the time display from the mobile of the clockwork mechanism around an off-center shaft orients parallel to the axis of revolution, and in that the catch-up mechanism is located on the same main face as the return mechanism.

An advantage of the invention results from the fact that the take-up mechanism no longer interferes with the automatic winding mechanism, this facilitating the construction of the movement.

Another advantage of the invention is that the construction described can be used to transform easily and inexpensively an existing chronograph movement with automatic winding, without split-seconds but inexpensive, into an automatic chronograph movement with split-seconds.

Other characteristics and advantages of the movement according to the present invention will emerge from the description which follows, given with reference to the appended drawing and giving, by way of explanation but in no way limitative, an exemplary embodiment of such a movement. In this drawing, where the same references relate to similar elements:

- fig. 1 shows a watch fitted with a conventional automatic chronograph movement without a retracting hand;

- fig. 2 shows a watch fitted with an automatic split-seconds chronograph movement according to the invention;

- fig. 3 is a plan view, from the face supporting the dial, of the chronograph movement according to the invention; and

- fig. 4 is a partial sectional view of the movement of FIG. 3 showing the return mechanism, and partially that of the catch.

The movement according to the present invention could, of course, be described as an entirely new embodiment. It is however preferable to present it as the result of a transformation carried out on an existing conventional movement. This will highlight the advantage of an invention making it possible, thanks to an inexpensive transformation carried out on a movement of wide distribution and inexpensive, to obtain a movement having the characteristics of much more expensive movements.

The piece on which the transformation will be described is the automatic chronograph movement Valjoux 7750, produced by Eta S.A. in Granges (Switzerland). This movement, of circular shape, is delimited by two main faces which are substantially flat and parallel. One side supports a dial, and the other side the oscillating weight of an automatic winding device. Of course any other similar movement could also be suitable.

Fig. 1 shows a chronograph watch fitted with such a Valjoux movement. Around an axis of revolution xx ', visible in fig. 4, passing through the center of the movement perpendicular to the main faces, rotate an hour hand 1,

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a minute hand 2, and a chronograph hand 3. A shorter hand 4, arranged at 9 o'clock, indicates the current second, while a window calendar 5 placed at 3 o'clock displays the day and the date. The chronograph device also includes a hand 6 totaling the minutes, and a hand 7 totaling the hours, these hands being located at 12 and 6 o'clock respectively. A time-setting device makes it possible to move hands 1 and 2 by means of a crown 8 and to modify the calendar indications, while push-buttons 9 and 10, by acting on a device for controlling the chronograph, allow to start, stop, or reset the hand 3.

In fig. 2 shows a watch comprising a movement according to the invention. On this watch are found the reference bodies 3, 4, 6, 7, 8, 9 and 10, previously described and which fulfill the same functions in both cases. Instead of calendar 5, however, there are hands 1 ′ and 2 ′ respectively indicating the hours and the minutes, while concentrically with the needle 3 pivots a catch-up hand 11, this latter hand being controlled by a push-button 12.

The movement of the watch represents in fig. 2 can be obtained by means of a modification made to the Valjoux movement already mentioned. This modification, which will be described in detail using FIGS. 3 and 4, consists essentially, first, of removing your hands 1 and 2 displaying the time as well as the calendar organs 5. It consists, then, of implanting on this movement the hands 1 'and 2' with a mechanism return gear intended to drive them, then the take-up needle 11 and the pusher 12, finally a take-up mechanism controlling the needle 11 in response to an action on the pusher 12.

In fig. 3 and 4 the reference 20 designates the plate of the Valjoux 7750 movement, and the reference 21 the main face of this movement which is located opposite the dial 22, this dial being that of the watch shown in FIG. 2. In the plate 20 is driven a hollow shaft 23 having the axis xx 'as an axis of symmetry. On the shaft 23 freely pivots a pinion 24. This pinion, which initially supported the barrel on which the needle 2 was fixed, is rotated at the speed of 1 revolution per hour by a toothed wheel 25 of the clockwork mechanism not shown being part of the movement. The needles 1 'and 2' are supported, on their side, by a new timer bridge 26, this bridge being fixed by means not shown on the face 21 of the plate. In this bridge is driven a shaft 27 on which pivots a barrel 28 supporting the minute hand 2 '. The barrel 28 has a pinion 29 which meshes with a timing gear wheel 30. The wheel 30 pivots on a shaft 31 secured to the bridge 26, and it meshes with the pinion 24 so as to rotate the barrel 28 at the rate of 1 turn per hour. On the barrel 28 pivots a barrel 32 which supports the hour hand 1 '. The barrel 32 is integral with a toothed wheel 33. The wheel 33, on its side, meshes with a pinion 34 pivoting on the shaft 31 and on which the wheel 30 is fixed, to drive the barrel 32 in rotation at the rate of 1 tour in 12 or 24 hours.

The mobiles 28, 29, 30, 32, 33 and 34 constitute the deflection mechanism, arranged under the dial 22, which has the function of driving the hands 1 'and 2' from the pinion 24, the pinion which supported the barrel of the minute hand 2 before transforming the movement.

Of course, the time-setting mechanism, which does not represent movement, enables the hands 1 'and 2' to be controlled by means of the crown 8 in the same way as it controlled the hands 1 and 2.

As regards the chronograph function, the chronograph hand 3 is fixed on a shaft 40 rotating at the speed of 1 revolution per minute. This shaft, which is part of the chronograph mechanism, not shown in the movement, pivots around the axis xx 'inside the hollow shaft 23. On the shaft 40 is still fixed, on the side of the dial 22 and in contact pinion 24, a heart-shaped cam 41. Above this cam freely pivots on the shaft 40 a barrel 42, this barrel supporting at one end the catch-up needle 11, and at the other end a catch-up wheel 43. On this last wheel is fixed a lever 44 to the by means of a screw 45 which allows the lever to pivot in a plane perpendicular to the axis xx '. The free end of the lever 44 is finally pressed against the cam 41 by means of a spring 46 placed between the lever and the wheel 43.

Under these conditions, the force exerted by the lever 44 on the cam 41 rotates the wheel 43 with the barrel 42 on the shaft 40 so that the end of the lever moves to the shortest distance from the axis. xx 'allowed by the cam. The chronograph control device still allows, for its part, by means of pushers 9 and 10, to act on the chronograph mechanism to measure a time interval. Now this interval is indicated by the two hands 3 and 11, arranged exactly opposite one another and moving in synchronism.

So that the needle 11 can fulfill its catch-up function, a catch-up mechanism is still installed on the main face 21 of the movement. This mechanism is controlled by the pusher 12 and it makes it possible, in response to a pressure on the latter, to block the needle 11, and in response to the next pressure, to release this needle so that it returns to its place opposite of needle 3 by the action of lever 44 on cam 41.

The locking of the needle 11 is obtained by means of a clamp comprising two branches, referenced respectively 50 and 51, the free ends of which grip the wheel 43 with a certain pressure to immobilize it. This pressure is given by a spring 52 bearing on the two branches. The force produced by the spring 46 is chosen, on its side, so that, when the needle 11 is blocked while the needle 3 is rotating, the torque exerted by the shaft 40 is sufficient for it to be able to overcome that produced by the action of lever 44 on cam 41.

Between the branches 50 and 51 of the clamp is disposed a toothed wheel 53 comprising 2N radial teeth 54, and N axial teeth 55. The teeth 54 are hole5

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wind in the plane of the wheel, while the teeth 55 are constituted by columns oriented perpendicular to this plane. A jumper 56, resting on the teeth 54, angularly positions the wheel 53.

The branch 50 has, facing the teeth 55 of the wheel 53, an inclined plane 57, and the branch 51 a similar inclined plane 58. In a position of the wheel 53, corresponding to that shown in FIG. 3, the inclined planes 57 and 58 are each located between two adjacent teeth 55. The ends of the arms 50 and 51 are then, by the action of the spring 52, in contact with the wheel 43 with sufficient pressure to immobilize by friction this wheel and the hand 11, allowing the reading of an intermediate timed time interval while the hand 3 continues to rotate.

The wheel 53, passing in the following position, brings a tooth 55 in contact with the inclined plane 57, and another tooth in contact with the inclined plane 58. These teeth, by sliding on the corresponding inclined planes, separate the branches 50 and 51 of the wheel 43 to release this wheel and the needle 11, the latter then being placed, by virtue of the action of the lever 44 on the cam 41, opposite the needle 3 still in rotation.

The rotation of the wheel 53 in successive steps, making it possible to time a series of intermediate times, is obtained by means of a slide 59 moving radially on the main face 21 of the movement. One end of the slide is integral with the pusher 12, while the other end abuts against a tooth 54 of the wheel 53. A pressure on the pusher 12, by moving the slide 59 from a rest position to a position of work, makes it possible to rotate the wheel 53 with a pitch of a tooth. The pusher 12 once released, the slide returns to the rest position thanks to a return spring 60, and to a lateral clearance 61 in the guide device allowing its end, during the recoil, to pass over a tooth 54.

The Valjoux movement thus transformed naturally presents a height on the dial greater than that of the original movement. On the other hand, the total height measured on the axis xx 'is the same in both cases, because, instead of having the three hands 1, 2 and 3 in the center, the modified movement only has the two hands 3 and 11.

It is understood that the chronometer movement which has just been described can undergo different modifications and be presented in other variants, obvious to a person skilled in the art, without departing from the scope of the present invention.

Claims (6)

Claims 1. Analog mechanical movement with automatic balance-sprung balance-spring for watch, comprising two main faces which are substantially flat and parallel, one of the faces (21) supporting the dial (22) of the watch, a clockwork mechanism driving in rotation around an axis of revolution (xx '), arranged perpendicular to said faces and passing through the center of the movement, a mobile (24) capable of indicating the time, an analog device for displaying the time by hands ( 1 ', 2'), time setting means (8) acting on said clock mechanism, a chronograph mechanism for measuring a time interval driving a chronograph hand (3) and a hand split-second (11) around said axis of revolution (xx ') to indicate and store the duration of said time interval, control means (9,10,12) of said chronograph mechanism, a catch-up mechanism (41, 43, 44 , 50, 51, 53, 57, 58, 59) acting on said retracting needle (11) in response to an action on a member (12) of said control means, and an automatic winding mechanism by oscillating weight disposed on the other main face, characterized in that it further comprises a return mechanism (28, 29, 30, 32, 33, 34), disposed on said main face (21) of the movement which supports said dial (22), for driving said hands (1 ', 2') of said display from of said mobile (24) around an off-center shaft (27) oriented parallel to said axis of revolution (xx '), and in that said catch-up mechanism (41, 43, 44, 50, 51, 53, 57, 58, 59) is located on the same main face (21) as said return mechanism. 2. Movement according to claim 1, characterized in that said mobile is constituted by a pinion (24) forming part of said clockwork mechanism and which performs one complete revolution per hour. 3. Movement according to claim 1 or 2, characterized in that said off-center shaft (27) is arranged at 3 o'clock on the side of said main face (21). 4. Movement according to one of the preceding claims, characterized in that said return mechanism comprises: - a timer gear (30) pivoting on a timer shaft (31) and meshing with said mobile (24) of said clock mechanism; - a minute pinion (29) pivoting on said off-center shaft (27) and meshing with said timer wheel (30); - a minute barrel (28) integral with the minute pinion (29) and supporting the hand (2 ') of said hour display which indicates the minutes; - a pinion (34) integral with the timer wheel (30); - a toothed hour wheel (33) pivoting on the minute barrel (28) and which meshes with the pinion (34) integral with the timer wheel (30); and - an hour cannon (32) integral with the hour wheel (33) and supporting the hand (1 ') of said hour display which indicates the hours, the number of teeth of the different mobiles being chosen so that the minute cannon (28) makes 1 turn per hour, and the hour cannon (32) 1 turn in 12 or 24 hours. 5. Movement according to claim 4, characterized in that the timer shaft (31) and the off-center shaft (27) are fixed on a timer bridge (26) disposed on said main face (21). 6. Movement according to one of the preceding claims, characterized in that the said catch-up mechanism comprises: - a heart-shaped cam (41) fixed on a shaft 5 10 15 20 25 30 35 40 45 50 55 60 65 5 CH 682 201G A3 central (40) of said chronograph mechanism, said shaft supporting the chronograph hand (3); - a split-second wheel (43) pivoting freely on said central shaft and which comprises a lever (44) coming to press elastically with a force given on said cam (41); - a clamp comprising two branches (50, 51) and an inclined plane (57, 58) on each branch arranged opposite the other branch, the free ends of the branches enclosing the take-up wheel (43) 10 to immobilize it by friction effect; - a toothed wheel (53) comprising 2N radial teeth (54) and N axial teeth (55) and capable of occupying 2N positions determined by a jumper (56) acting on the radial teeth, in one of said positions of the wheel inclined planes (57, 58) are located between two adjacent axial teeth (55), and in the following position an axial tooth penetrating on each inclined plane to separate the branches from one another and release the split-second wheel (43 ); 20 and - a slide (59) movable radially on the movement, one end of the slide comprising a pusher (12) forming part of said control means, and the other end coming to bear against a radial tooth (54) for passing said toothed wheel (53) from one position to the next position in response to each press of the pusher (12). 35 40 45 50 55 60 65 6