CH704680A2 - Timepiece movement for rotating e.g. civil time hour hand, has time equation lever mounted to pivot on toothed wheels in off-centered position, and spring arranged on wheels to recall free end of lever against core - Google Patents

Abstract

The movement has a correction mechanism including a blocking unit formed of dual-spring (120), locking clip (121) and T-shaped small lever (124) to block and release an hour wheel (113) when stop force and force are respectively applied on a control lever. A pivoted lever (103), toothed sector (105) and mobiles (107, 109) connect a profile of a time equation lever (115) to toothed wheels (111, 112). The time equation lever is mounted to pivot on the toothed wheels in buckled position. A spring (123) is arranged on the toothed wheels to recall a free end of the lever against a core (119).

Description

Field of the invention

The present invention relates to a complicated timepiece movement intended to rotate a minute hand and a minute hands of the civil time and comprising a device with equation of walking time provided to drive a minute hand of the solar time in rotation coaxially with the hands of the minutes and the hours of the civil time.

As we know, there is a difference between the true solar time which corresponds to the duration that elapses between two consecutive upper passes of the Sun to the meridian of the same place, and the civil time which is the average, made on the year, the duration of all solar days true. This difference between the civil time and the true solar time reaches + 14min. 22 s. February 11, -16 min. 23 s. on November 4th, and vanishes on April 15th, June 13th, September 1st, and December 25th. These values vary little from year to year.

Prior art

To indicate the difference between the civil time and the solar time, certain timepieces include a device said equation of walking time, that is to say, whose switch has two hands concentric minutes, the one indicating the civil time, and the other the solar time, the hand of the minutes of solar time being controlled by a time equation cam whose profile is determined by the difference between the mean solar time and the time true at a given moment.

[0004] Patent document CH 689 359, in particular, describes a watch movement comprising such a device with a walking time equation. According to this document, the device comprises a time equation cam rotated by the movement at the rate of one revolution per year. This cam cooperates with one end of a rocker, while the other end of the rocker extends facing the axis of rotation of the needles. Thus, when turning, the equation of time cam rotates the rocker, this pivoting varies the distance between the free end of the rocker and the axis of the needles. The end of the latch facing the needles is provided with an inclined arranged to serve as a cam sector to set the hour of solar minutes time once a day.

The device with equation of walking time further comprises a gun provided with a pinion and provided to carry the minute hand of solar time. This gun is rotatably mounted concentrically to the hands of minutes and hours of civil time. The correction mechanism of the walking time equation further comprises a solidarity support in rotation of the minute hand of the civil time. A rake is rotated on the support, and the toothed sector of the rake is arranged to mesh with the pinion of the gun of the minute hand of solar time. In contrast to the toothed sector, the handle of the rake carries a positioning stud. It will be understood that the positioning stud rotates about the axis of the needles with the support. It turns therefore at the speed of the minute hand of the civil time. If, in its race, the positioning pin meets the slope of the equation of time lever, it slides against it. The reaction force exerted by the inclined on the pad flaps the latter in the direction of the axis of rotation of the needles. Thus, the stud is forced to deviate from its circular path, which rotates the rake. By pivoting, the rake carries with it the pinion of the barrel, which rotates the friction barrel and drives the minute hand of the solar time which turns in the clockwise direction. The rake being rotated on the support, the rotation of the barrel is carried out with respect to the support and thus with respect to the hand of the minutes of the civil time. It will be understood from the foregoing that it is the distance between the positioning pin and the axis of rotation of the needles at the instant when the pin arrives at the end of the inclined, which determines the exact position of the minute hand of solar time.

The mechanism just described allows only the correction of the position of the minute hand of solar time in the clockwise direction. This is the reason why a second mechanism is provided to retract the needle. This second mechanism comprises disengaging means for disengaging the barrel of the minute hand of the solar time. These disengaging means are arranged to release the barrel when a force is applied to a control lever provided for this purpose, and to lock the barrel again when the force ceases to be applied. The second mechanism further comprises a triggering device which is controlled by the movement to apply a force, once every 24 hours, on the control lever of the disengaging means. In response to this force, the disengaging means disengage the gun of the minutes of solar time, so that it becomes free to rotate relative to the minute hand of the civil time. Note that the engagement of the rake with the pinion of the gun is not affected by this disengagement. The second mechanism further comprises a small spring mounted on the support and which is arranged to push the rake so as to bias the pinion and barrel counterclockwise. Thus, when the barrel is disengaged, the small spring rotates the rake, removing the positioning pin from the axis of rotation of the needles. The triggering device controlled by the movement is provided to actuate the disengaging means at a time when the positioning pin is facing the beginning of the inclined. Thus, when the barrel is disengaged, it rotates counterclockwise until the positioning pin is retained by the inclined against which it abuts.

It will therefore be understood that with the walking equation of walking time that has just been described, the correction of the position of the minute hand of the solar time is done once per 24 hours in two stages. At first, the minute hand of the solar time rotates counterclockwise until it is in a position lagging behind the solar time. Then, in a second step, the minute hand of the solar time is brought back clockwise to the position determined by the time equation cam. This device has some defects. On the one hand the need to have a second mechanism to retreat the needle greatly complicates the construction. On the other hand, the barrel of the minute hand of solar time has, at all times, the possibility of turning frictionally relative to the minute hand of the civil time. This possibility can be problematic in case of shock. In fact, a shock of moderate intensity can suffice to distort the gap between the hands of civil time and solar time. Finally, the force of the small spring must be too weak to rotate the friction barrel, and at the same time, it must be sufficient to turn it when it is disengaged. The described arrangement therefore involves some adjustment difficulties.

Brief description of the invention

An object of the present invention is therefore to overcome the disadvantages of the prior art which have just been described, and in particular to correct the equation of walking time clockwise and counterclockwise with the same mechanism. . The present invention achieves this goal by providing a timepiece movement having a walking time equation device according to the appended claim 1.

According to the invention, the frame is kinematically connected to the equation of time cam. The angular position of the chassis is therefore representative of the difference between civil time and solar time. On the other hand, the chassis carries the equation of time lever, the latter being recalled against the periphery of the heart. Thus, in a manner known per se, the force exerted by the lever on the heart generates a torque that tends to return the heart to an equilibrium angular position. Since the time equation lever is mounted on the frame, the equilibrium angular position is related to the angular position of the frame. The position of the heart at equilibrium is therefore representative of the difference between civil time and solar time.

The heart is integral with the barrel provided to carry the minute hand of solar time. The heart is thus retained by the barrel as long as no force is exerted on the control lever of the locking means. When at a given moment, a pressure is exerted on the control lever, this pressure causes the release of the barrel which is then free to rotate with the heart. As we saw above, the heart and the cannon are then recalled to a position of equilibrium representative of the gap between the civil time and the solar time. The heart and the barrel then remain in the equilibrium position until the locking means are closed again. Moments later, the pressure on the control lever stops, and the locking means again block the barrel. From this moment, the minute hand of the solar time and the hand of the minutes of the civil time are held together and rotate in concert, at the speed of one turn per hour.

It will be further understood that when the blocking means block the barrel, the angular difference between the two minute hands is determined, on the one hand, by the shift between civil time and solar time, and secondly, by the position occupied by the minute hand of the civil time at the precise moment when the blocking means blocked the barrel. With this system, it is therefore necessary that the minute hand of the civil time occupies a very precise position at the moment of blocking, so that the angular difference between the two needles corresponds well to the shift between civil time and solar time. . Since the minute hand of the civil time is intended to return to the same position exactly once an hour, the periodic adjustment of the angular offset between the minute hand of the solar time and the minute hand of the civilian time must be performed at a specific minute and can be done only once an hour at most. In other words, the period between two consecutive adjustments must correspond to a whole number of hours.

Brief description of the figures

Other features and advantages of the present invention will appear on reading the description which follows, given solely by way of non-limiting example, and with reference to the accompanying drawings in which: - fig. 1 is a schematic top view (from the bridge side) of a particular embodiment of the walking time equation device of the complication timepiece movement of the present invention; - fig. 2is a partial perspective view of the equation device of the walking time of FIG. 1; - fig. 3 is a partial schematic view from above showing the triggering device of the correction mechanism of the equation device of the walking time of FIGS. 1 and 2; - fig. 4 is a schematic bottom view (from the dial side) showing the triggering device of FIG. 3; - fig. 5 is an enlarged partial view from above showing the triggering device of FIGS. 3 and 4 in its configuration at the instant preceding the jump: - fig. 6 is a partial view similar to that of FIG. And showing the configuration of the trigger device during the jump; - fig. 7 is an enlarged schematic view of the eccentric of the triggering device of FIGS. 3 to 6 in its configuration at the instant before the jump.

Detailed description of an embodiment

The watch movement of the present invention preferably comprises a perpetual calendar mechanism or another type of calendar mechanism with date and month indication. Note, however, that the present invention is not limited to movements with a calendar.

The watch movement of the present example comprises a calendar mechanism. However, in what follows, we will not describe the watch movement in its entirety but only the equation mechanism of walking time. Concerning the calendar, suffice to specify that the indication of the date is implemented in a known manner thanks to a mobile of 31 driven at a rate of one turn per month, and that the mobile of 31 drives itself, by the intermediate gear a gear ratio 1/12, a time equation cam 101 provided to perform a complete revolution in one year. In a known way, the radius of the equation cam of time expresses in each point of its circumference the value of the difference between the civil time and the true solar time for a given day of the year.

Referring firstly to FIG. 1, it can be seen that the walking time equation device also comprises a pivoted lever 103. This lever is subjected to a return action of a spring (not shown) tending to apply the probe 104 forming the distal end of the lever. lever against the periphery of the time equation cam 101. The pivoted lever 103 is rotationally integral with a first gear sector 105 which constitutes the first element of a gear wheel actuated by the time equation cam 101. the first gear sector, the gear train comprises a toothed wheel 111 pivotally mounted concentrically at the switch of the movement, and a first mobile 107, formed of a pinion and a toothed sector, and a second mobile 109 also formed of a pinion and a toothed sector. The first and the second mobile are interposed between the first toothed sector and the toothed wheel 111. The first toothed sector 105 meshes with the pinion of the first mobile 107, the toothed sector of the first mobile meshes with the pinion of the second mobile 109, and finally the toothed sector of the second mobile meshes with the toothed wheel 111. The gear ratio of the gear is selected according to the dimensions of the equation cam of the time 101, so that a variation of one minute of the Equation of time is ultimately translated by a rotation of 6 ° degrees of the toothed wheel 111. It will therefore be understood, in particular, that the angular position of the wheel 111 is representative of the difference between the civil time and the solar time.

Referring now to FIG. 2, we can see in the figure that the movement further comprises a mobile 125 whose axis 126 carries the minute hand of the civil time (not shown). The mobile 125 will be called hereinafter "the false floor". The walking time equation device further comprises a gun 113 freely fitted on the axis 126 and carrying the minute hand of the solar time (not shown). It can be seen again that a locking clamp 121 surrounds the barrel 113. This clamp is articulated on a pivot 122 which is fixed in an eccentric position on the board of the false floor 125. A double spring 120 recalls the jaws of the clamp blocking against the outside of the barrel 113. Finally, a small lever T-shaped 124 is pivoted at the base of the T on the board of the false floor 125. The small lever 124 is arranged so that a force exerted on a first end 126 of the bar of the T causes the other end 128 to be inserted between the jaws of the clamp 121 and serve as a wedge to spread them. It will be understood that when the jaws of the locking clamp 121 are closed, the barrel 113 is integral with the false floor 125 which drives it in rotation. Thus, the angle made by the minute hand of the solar time with the minute hand of the civil time can not be modified as long as no force is exerted on the end 126 of the small control lever 124.

The walking time equation device further comprises a heart 119 which is driven on the barrel 113 and an equation of time lever 115 whose end is biased against the periphery of the heart by a spring 123. D ' on the other hand, as can be seen in fig. 1, a radial arm referenced 112 is fixed on the toothed wheel 111. It can be seen in FIG. 2que the arm 112 extends first radially beyond the teeth of the false floor 125, to then curve upwards and end approximately opposite the heart 119. The end of the arm 112 form a small off-center support 116, and it will be understood that the function of the toothed wheel 111 with its arm 112 is that of a rotating frame. We can still see in fig. 2 that the small support 116 serves both as an anchor point for the spring 123 and a pivot point for the time equation lever 115. Finally, it can be seen that the equation lever of the time 115 carries to its end a roller 117 and that the roller is pressed against the periphery of the heart 119 by the spring 123. In known manner, the force exerted by the roller 117 on the heart has a tangential component that tends to recall the heart to the heart from its stable equilibrium angular position, or in other words, towards the position where the roll is in the tick of the heart.

The walking time equation device further comprises a trigger device driven by the movement and which will be described in detail later.

The operation of the walking time equation device which is the subject of the present example will now be described. As we have seen, as long as no force is exerted on the control lever 124, the barrel 113 and the heart 119 are integral with the false floor 125 which drives them in rotation. In accordance with what will be described above, the trigger device is arranged to press the end 126 of the small lever 124 once every 3 hours. The triggering device thus forces the jaws of the locking clamp 121 to open and release their pressure on the barrel 113. Released by the clamp, the barrel pivots driven by the heart until the roller 117 s' immobilize in the check of the heart. It will be understood that the position occupied by the minute hand of the solar time at this precise moment depends on the angular position of the frame 111 and therefore of that of the equation cam of the time 101. A few moments later, the device of triggering stops pressing the control lever 124 and the jaws of the clamp 121 are closed on the barrel 113 freezing for the next 3 hours the angle between the two minute hands. In this regard, it will be understood that the angle between the two minute hands at the instant when the clamp 121 closes on the barrel 113 is determined, on the one hand, by the position of the equation cam of the time, and on the other hand, by the position occupied by the minute hand of the civil time at this moment. The position occupied by the minute hand of the civil time, at the instant when the locking means are closed again, is therefore critical for the walking time equation device operation of the present invention.

The triggering device of the correction mechanism of the walking time equation will now be described with reference to FIGS. 3 to 7. As can be seen in the figures, the triggering device comprises a trailing wheel 205, a finger 213 (FIG 3) idly mounted on the axis of the trailing wheel, an eccentric 207 (FIG 4) which is also mounted idle on the axis of the trailing wheel, but on the opposite side with respect to the finger, a lever 217 carrying a wheel 219 (Figures 5 and 6), a spring (not shown) arranged to recall the lever wheel against the circumference of the eccentric, and finally a rocker 209.

In the present example, the trailing wheel 205 is driven by the timer of the movement (not shown) at the substantially constant speed of a revolution every 3 hours. The trailing wheel will henceforth be called "the 3-hour wheel". However, it will be understood that this wheel could be driven at a different speed. Indeed, for the device to work properly, it is sufficient that it performs exactly one revolution in N hours, the parameter "N" can be any integer greater than or equal to 1. It will be understood, on the other hand that the kinematic chain which drives the trailing wheel does not necessarily go through the timer.

We can see in fig. 7the shape of the eccentric 207 is doubly asymmetrical. In fact, on the one hand, the distance separating its periphery from its center of rotation is not constant, and on the other hand, it is also observed that the vertex of the curve (that is to say the point the farther from the center of rotation) is not situated opposite the birth of the curve (that is, from the point closest to the center of rotation). The radius leading to the top of the curve (referenced u) and the radius leading to the birth of the curve (referenced v) thus share the area enclosed by the curve in two unequal sectors. The largest of these sectors will be referred to hereinafter as the low tilt sector 223, and the smaller one will be referred to as the high tilt sector 225. Referring again to FIGS. 3, 5 and 6, it can be seen that the board of the 3 o'clock wheel 205 is pierced with an oblong 206 which defines a circular arc, and that the eccentric 207 carries a pin 215 which is arranged to slide in this oblong. The presence of the oblong allows the eccentric to pivot relative to the 3-hour wheel within a sector whose extent is limited by the two ends of the oblong.

In FIG. 5, the pin 215 is shown bearing against one end of the oblong 206. In this situation, the 3 hour wheel 205 drives the eccentric 207 in rotation through the pin. The rotation of the eccentric further constrains the wheel 219 to roll on the periphery of the latter. In addition, the direction of rotation of the wheel 3 hours is such that the wheel rises along the curve, away from the center of rotation, when it crosses the low inclination sector 223, and goes down again, recalled by the spring (not shown) in the direction of the center of rotation, when it passes through the high inclination sector 225. When the wheel and the lever 217 thus crosses the high inclination sector, the force exerted by the spring on the inclined periphery eccentric 207 has the effect of driving the eccentric in the same direction as the driving force of the cog. Since the eccentric is free to pivot relative to the 3-hour wheel, the roller 219 rapidly rises the inclined edge of the crown until the curve is born, causing the eccentric and the pin 215 to pivot in the opposite direction. a walk. The fall of the wheel ends when it comes to rest at the birth of the curve (in the position shown in Fig. 6).

The length of the pin 215 is such that its end protrudes from the oblong 206, so that it can push the finger 213. In FIG. 5, the finger 213 is shown bearing against the pin. In this situation, the eccentric 207 drives the finger 213 in rotation through the pin. Once per turn of the wheel of 3 hours 205, the finger meets the rocker 209 and raises the latter. The triggering device is arranged so that the finger meets the rocker approximately at the moment when the wheel 219 begins to roll down the inclined periphery of the eccentric. Thus, pushed by the lever 217, the finger pivots violently, lifting the rocker 209 and sliding rapidly against its concave face, until the finger has passed the maximum lifting point of the rocker (as shown in Fig. 6) . The spring will preferably be arranged to exert as strong a thrust as possible, so that the pivoting movement of the eccentric and the finger is very fast.

As can still be seen in the figures, when the rocker 209 is raised by the finger 213, the back of the rocker is pressed against the end 126 of the small control lever 124 with sufficient force to open up the jaws of the locking clamp 121 and to release the barrel 113. To open the jaws of the locking clamp, the rocker arm must constrain the double spring 120, and it will be understood that, by reaction, the rocker is then recalled against the finger 213 by the double spring (120). This reaction force has no effect as long as the pin is pushed by the pin 215 and the maximum lifting point of the rocker arm is not reached. On the other hand, as soon as the finger exceeds the maximum lifting point of the rocker (Fig. 6), the tangential component of the reaction force exerted by the rocker arm on the finger is oriented in the direction of rotation. The finger then being free to rotate relative to the eccentric and the wheel of 3 hours, the rocker falls by ejecting the finger. The pressure of the rocker arm on the control lever suddenly stops, allowing the locking clamp to immobilize the barrel at a specific time.

Those skilled in the art will appreciate that the trigger device that has just been described is of the so-called "instantaneous" type. Indeed, the duration of the period during which the triggering means press on the lever 124 is not determined by the speed of rotation of the trailing wheel, but by a double trigger involving first the powerful spring of the lever 217 and then the double spring (120). On the other hand, as explained above, the triggering device also determines when the blocking means release the barrel 113 and when they block it again. The revolutions of the trailing wheel 205 taking exactly 3 hours, the position of the minute hand of the civil time at the moment when the locking means are actuated is always the same. The walking time equation device is preferably arranged so that the minute hand of the civil time occupies the "12 o'clock" position at the moment when the locking means once again block the barrel after leaving it free. moments. Note that the choice of the "12 o'clock" position, or any other particular position given, does not imply any technical difficulty, since at assembly, the two minute hands and the heart 119 can be driven in any angular position on their axis (referenced 113 and 126).

It will further be understood that various modifications and / or improvements obvious to a person skilled in the art can be made to the embodiment which is the subject of the present description without departing from the scope of the present invention defined by the appended claims. In particular, the triggering device need not be of the instantaneous type, but could be of the trailing type. In this case, a finger 213 could for example rotate integrally with the trailing wheel 205. The length of the finger would be determined so that the trajectory of the finger intersects once per turn that of the first end 126 of the trigger lever 124. The shape of the end of the finger and that of the lever 124 would then be advantageously designed so that after being in contact, the finger and the lever separates at once, without transition.

Claims (9)

A movement for a timepiece with a complication intended to rotate a minute hand and a minute hands of the civil time and comprising a walking time equation device comprising a gun (113) mounted concentrically rotatable to the minute hands. and hours of civil time and intended to carry a minute hand of solar time, the time equation device including a time equation cam (101) rotated by the motion at a rate of one revolution per year , and a correction mechanism provided for periodically adjusting the angular offset of the minute hand of the solar time relative to the minute hand of the civil time, depending on the angular position of the time equation cam, the correction mechanism comprising: - Locking means (120, 121, 124) comprising a control lever (124) and provided for securing said barrel (113) and the minute hand of the civil time, said locking means being arranged to release said barrel when a force is applied to said control lever and to re-lock said barrel when said force ceases to be applied; A motion driven triggering device (205, 207, 209, 213) for periodically applying a force to said control lever (124) at a regular interval corresponding to a whole number of hours; characterized in that the correction mechanism further comprises: - a heart (119) integral with said barrel (113), and a time equation lever (115) provided to cooperate with the heart; A kinematic connection (103, 104, 105, 107, 109) connecting the profile of the equation of time cam (101) to a frame (111, 112) concentrically pivoted to the axes of the needles, the equation lever of the time (115) being pivotally mounted on the frame in off-center position, a spring (123) being further arranged on the frame so as to recall a free end of the time equation lever against the core. 2. movement for timepiece according to claim 1, characterized in that the locking means (120, 121, 124) comprise a locking clip (121) integral with the minute hand of the civil time, the clip of blocking being associated, on the one hand, with a spring (120) arranged to close the clamp around said barrel (113) to secure it to the minute hand of the civil time, and associated on the other hand, to said control lever (124), the control lever being arranged to open the clamp when a force is applied to the control lever. 3. Timepiece movement according to claim 1 or 2, characterized in that said kinematic connection (103, 104, 105, 107, 109) between the time equation cam (101) and the frame (111, 112) comprises a rake (103, 104, 105) whose handle (104) is arranged to cooperate with the profile of said cam, and a gear train (107, 109) connecting the toothed sector (105) of the rake to a toothing integral with the frame, said toothing being concentric with the axis of the needles. 4. Movement for a timepiece according to one of claims 1, 2 or 3, characterized in that the time equation lever (115) has at its end a roller (117) biased against the heart (119) and arranged to roll against the profile of the heart. 5. Motion for a timepiece according to one of the preceding claims, characterized in that said triggering device (205, 207, 209, 213) is actuated by a trailing wheel (205) driven by the movement to the rhythm of one revolution every N hours, N being a positive integer. 6. movement for timepiece according to claim 5, characterized in that said triggering device (205, 207, 209, 213) comprises a finger (213) driven by the trailing wheel (205) and provided for actuating said lever control (124). 7. Movement for a timepiece according to claim 6, characterized in that said triggering device (205, 207, 209, 213) comprises an eccentric (207) driven by the trailing wheel (205) via a pin (215) arranged to slide in an oblong (206), and a wheel (219) biased by a spring against the periphery of the eccentric, and in that the trailing wheel drives the finger (213) through of the eccentric. 8. Movement for a timepiece according to claim 6 or 7, characterized in that the finger (213) actuates the control lever (124) via a rocker arm (209). 9. Timepiece movement according to one of claims 5 to 8, characterized in that the trailing wheel (205) is driven by the timer of the movement at the rate of one revolution every 3 hours.