Classifications

• • G—PHYSICS
  • G04—HOROLOGY
  • G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
  • G04B19/00—Indicating the time by visual means
  • G04B19/02—Back-gearing arrangements between gear train and hands

Definitions

• the present invention relates to a display module, for watch movement for driving a retrograde display member of at least one hourly information, comprising a frame carrying drive means for driving the body of the invention.
• display comprising a mobile, intended to be driven by a finishing gear of the watch movement and carrying a first cam of the same axis of rotation with reference to the frame.
• the display module also comprises a rocker bearing a probe arranged to bear against the periphery of the first cam under the effect of deformable elastic means undergoing deformation of variable amplitude. The latter causes the application of a corresponding force on the rocker, depending on the distance separating the probe from the axis of rotation of the first cam.
• the display module further comprises transmission means for connecting the flip-flop to the drive means of the retrograde display member.
• the present invention also relates to a watch movement having the above characteristics and a timepiece comprising such a movement.
• patent CH 694 349 issued in the name of Franck Moller Watchland SA, describes a movement of this type intended to display both the minutes and the hours in a retrograde way.
• Each of the corresponding mechanisms comprises a rocker with two arms connected by a bend, in the region of which pivots the rocker relative to the frame of the movement.
• the free end of a first arm carries a feeler disposed in abutment against the periphery of a cam driven in rotation by the movement finishing work train, while the free end of the second arm carries a rake arranged in engagement with a mobile drive of a display member.
• a long spring is connected to the frame by a first of its ends while its second end is arranged to apply a force on the rocker, to maintain the probe in contact with the cam.
• This type of construction has certain drawbacks, particularly related to the application to the gear train of the movement, a friction force having a large amplitude variation between two extreme positions of the rocker. Indeed, it is found, on the one hand, that the axis of rotation of the rocker is relatively far from the probe and, secondly, that the point of support of the spring on the rocker is provided at the probe and is therefore also distant from the axis of rotation of the rocker. This results in a large amplitude of the deformations of the spring between the one and the other of the extreme positions of the rocker, ie a large amplitude of the variation of the force that this spring applies to the rocker.
• the rocker being disposed in abutment on a cam, itself driven in rotation by the gear train of the movement, there follows a disturbance of the movement of the movement which may have significant values of deviation.
• the present invention is intended to overcome the disadvantages of known mechanisms of the prior art, by proposing a movement for a retrograde timepiece in which the means of implementation of the retrograde display do not disturb almost no movement.
• the present invention relates more particularly to a movement for a timepiece of the type mentioned above, characterized in that a force regulating device is interposed between the elastic means and the rocker.
• the operation of the movement has a better accuracy.
• this accuracy is maintained even in the case where the movement is suitable for driving a display member over a large angular sector, in particular greater than 60 degrees, preferably greater than 120 degrees.
• the mobile is driven by a wheel frictionally mounted on a barrel wheel tube, the rocker having a rake having a gear arranged in engagement with a toothing of a pinion rotatably mounted on the barrel wheel tube and rotationally integral with an additional tube, the latter being intended to drive, at least indirectly, a display member of a time information.
• the force control device comprises a second cam integrally disposed to the rocker having the same axis of rotation as the latter.
• the elastic means preferably comprise a long spring having a straight portion of which a free end is disposed in abutment against the periphery of the second cam.
• the additional tube intended to carry the display member, is integral with an additional cam, with the same axis of rotation and having a periphery of variable radius intended to cooperate.
• an additional probe carried by an additional rocker the latter having a bearing surface arranged to cooperate with the elastic means.
• the rocker undergoes the force generated by the elastic means via its rake, the pinion and the additional cam whose periphery makes it possible to regulate the force effectively transmitted to the rocker. It may be preferable to provide that the periphery of the additional cam has a shape corresponding at least partially to a logarithmic curve portion.
• a roller may be carried by the additional probe to ensure the contact between the additional rocker and the periphery of the additional cam with the least friction possible.
• a movement can be implemented in a timepiece comprising a display member of a time magnitude scanning an angular sector of angle greater than 120 degrees, such as for example a display of hours on an area of 270 degrees.
• FIG. 1 represents a simplified top view of a detail of the movement for a timepiece according to a first variant of a preferred embodiment of the present invention, in a first configuration
• FIG. 2 shows a simplified top view similar to the view of Figure 1, in a second configuration
• FIG. 3 shows a simplified cross-sectional view of the movement of the preceding figures
• FIG. 4 represents a simplified top view of a detail of the timepiece movement according to a second variant of a preferred embodiment of the present invention, and [0021] FIG. simplified cross-sectional view of the movement of FIG. 4.
• Mode (s) of embodiment of the invention [0022]
• Figure 1 shows a top view of a construction detail of the movement according to a first variant of a preferred embodiment of the present invention, more particularly its mechanism for implementing a retrograde display. This mechanism is presented in a first configuration in FIG. 1 while it will be presented in a second, different configuration in FIG.
• the embodiment described relates to a drive mechanism of a pointer 1 indicating hours retrograde display type, particularly in relation to a graduated sector (not visible) s extending on an angle of 270 degrees.
• the implementation of the movement according to the invention is shown schematically in a timepiece comprising a box including a middle part 2.
• the movement comprises a plate (not shown) on which the display module and, in a hole of which is mounted a time setting rod 3, better visible in Figure 3.
• the hour hand 1 is disposed in the center of the timepiece being driven by a gun wheel (reference 4, Figure 3), the tube 5 carries an additional tube 6, mounted freely in rotation on the cannon wheel.
• the barrel wheel is driven in a conventional manner by a work train (not visible) of the movement, the latter being of mechanical or electromechanical type without affecting the object of the present invention.
• An hour wheel 7 is also mounted frictionally on the tube 5 of the barrel wheel.
• a mobile 8 is disposed at a distance from the hour wheel 7 and carries a control wheel 9 and a first cam 10 whose periphery has a spiral shape.
• the control wheel 9 and the first cam 10 are made integral in rotation, by means of a pin 11, and have a same axis of rotation 12 with reference to the frame of the movement.
• the control wheel 9 has a peripheral toothing arranged in engagement with the toothing of the hour wheel 7, so that the first cam 10 is rotated, in the counterclockwise in FIG. 1, by the movement of the hour wheel
• the retrograde display mechanism further comprises a rocker 20, rotatably mounted on the frame of the movement, along an axis X located in the immediate vicinity of the periphery of the control wheel 9. Starting from its mounted region pivoted on the X axis, the rocker 20 has two arms
• the first arm 21 initially comprises two portions 23 and 24 deviating from each other before joining to form a loop in the extension of which extends a feeler 25.
• free end 26 of the probe terminated in a point, is placed in abutment against the periphery of the first cam 10.
• the second arm 22 has an elongated and curved shape, to bypass the first cam 10, ending in a rake 27 , arranged in engagement with a pinion 28 secured to the additional tube 6.
• a second cam 30 is rotatably mounted on the axis X, being integral with the latch 20.
• the latter has a periphery in the shape of a heart, more precisely defined by a double curvature each of which corresponds to a portion of logarithmic curve.
• a long spring 31 is fixed to the frame of the movement, by means of a screw 32, by a first end 33 wound in the form of ring, while its second end 34 has a flat surface 35 disposed in abutment against the periphery of the second cam 30.
• a pin 36 integral with the frame, forms a counter-support to prevent the rotation of the spring in the counterclockwise direction.
• the rake 27 induces a rotational movement of the additional tube 6, in the clockwise direction, the latter being free to rotate relative to the barrel wheel.
• the hour hand 1 evolves with regard to graduations which can extend for example over twelve hours between the initial and final positions of the needle, these positions being spaced at an angle of 270 degrees according to the present method of realization, as an indication.
• the second cam 30 also rotates in the anti-clockwise direction by slightly deforming the spring 31 as its radius increases in the region of contact of the flat surface 35.
• the stiffness constant of the spring 31 is adjusted so that the contact of the tip 26 of the feeler on the periphery of the first cam is guaranteed at every moment, without generating too much friction.
• the feeler 25 thus has a gradual and continuous distance with reference to the axis of rotation 12 of the first cam 10. There are shown small crosses on the periphery of the first cam to identify the positions respectively corresponding to each of the hours displayed by the hour hand 1 opposite the graduations.
• FIG. 2 represents a view similar to that of FIG. 1, in a different configuration of the retrograde display mechanism, more precisely, a little less than twelve hours after the configuration of FIG. 1, the first cam 10 having performed almost a complete revolution in this interval.
• the hour hand 1 has undergone an angular displacement of the order of 270 degrees at the same time.
• the spring tension variation between these two extreme positions of the probe advantageously has a negligible impact on the progress of the finishing train.
• This particular characteristic also allows the use of indication sector of hourly magnitudes of greater angular amplitude than with the previous mechanisms.
• the action of the spring on the rocker, via the second cam 30, makes it possible to obtain a slower return of the hour hand 1 in its initial position than in the timepieces according to the prior art, in which the spring acts directly on the rocker.
• the theoretical return speed of the needle is constant during the duration of this movement due to the use of a logarithmic curve, which is not the case if the cam has a periphery whose shape is based on the Archimedean curve, particularly in the region of the rest position shown in Figure 1, so the former is preferred.
• FIG. 3 represents a simplified cross-sectional view of part of the movement that has just been described in relation with FIGS. 1 and
• the time setting rod 3 carries, in a conventional manner, a winding pinion 41 arranged in engagement with a crown wheel 42 of the movement, to effect the winding a barrel spring (not shown), and a sliding pinion 43 which can be brought into engagement with a return 44, itself engaged with the barrel wheel 4 to perform the time setting of display organs.
• the hour wheel 7 is driven simultaneously to the barrel wheel 4 to rotate the control wheel 9 and the first cam 10 and, consequently, the additional tube 6 carrying the hour hand 1.
• Figures 4 and 5 show, respectively in simplified top view and cross section, a display module for a watch movement according to a second variant of a preferred embodiment of the present invention.
• the second variant is distinguished from the first by a different arrangement of the elastic means to ensure a good quality of contact between the feeler 25 and the periphery of the first cam 10, the force control means applied to the rocker being adapted accordingly.
• the additional tube 6 carrying the pinion 28 is further secured to an additional cam 50 having a periphery of variable radius.
• the latter presents, from its lowest radius to its largest radius, a shape corresponding to a portion of a logarithmic curve. Furthermore, the regions of smaller radius and greater radius are connected by a substantially radial flank 51.
• the display module according to the second embodiment further comprises an additional rocker 52 rotatably mounted on the frame of the movement, along an axis of rotation located at a distance from the axis of rotation of the wheel. barrel 4.
• the additional rocker 52 comprises a base 53 from which extends an arm 54 whose free end carries a probe 55, here made in the form of a support 56 carrying a roller 57 intended for be placed in abutment against the periphery of the additional cam 50.
• the implementation of such a roller makes it possible to reduce the friction arising from the contact between the feeler 55 and the periphery of the additional cam 50, when the latter is rotated under the effect of the cooperation between the rake 27 and the pinion 28.
• the roller may be made of ruby or sapphire, as a non-limiting indication.
• the base 53 of the additional rocker comprises a bearing surface 58 having the shape of a ridge.
• a long spring 61 is fixed to the frame of the movement, by means of a screw 62, by a first end 63 wound in the form of a ring, while its second end 64, free, is disposed in abutment against the surface 58 of the additional cam 50.
• a screw 66 integral with the frame, forms a counter-support to prevent the rotation of the spring in the clockwise direction, thereby causing its deformation when the bearing surface 58 is driven in rotation in the counter-clockwise direction, due to the increase of the radius of the additional cam 50.
• the screw 66 is preferably an eccentric with which the orientation of the long spring 61 can be adjusted with a large position.
• the first cam 10 rotates in the direction of rotation anti-clockwise, it has a growing radius opposite the position of the probe 25, causing a rotation of the rocker 20 in the same direction .
• the rocker rotates relative to its axis X
• the rake 27 induces a rotational movement of the additional tube 6, in the clockwise direction, the latter being free to rotate relative to the barrel wheel.
• the hour hand 1 evolves with respect to graduations that can extend for example over twelve hours between the initial and final positions of the needle.
• the additional cam 50 rotates simultaneously in the clockwise direction, thus having an increasing radius to the probe 55 of the additional rocker 52 which rotates, thereby, in the counterclockwise direction.
• the rotation of the additional rocker causes a progressive deformation of the spring 61 as the radius of the periphery of the additional cam increases.
• the rocker 20 undergoes at each moment, except during the brief retrograde movement, two opposing forces, namely a first force tending to turn it in the counterclockwise direction and exerted by the periphery of the first cam 10, and a second force tending to turn it clockwise under the effect of the deformation of the spring 61, generating a force transmitted to the rocker 20 via the additional rocker 52, its probe 55 , the periphery of the additional cam 50, the pinion 28 and the rake 27.
• the force generated by the deformation of the spring 61 is regulated by the shape of the periphery of the additional cam 50 which makes it possible to control the corresponding torque transmitted to the pinion 28.
• the regulation is carried out here with a better precision insofar as the additional cam 50 has a rotation angle much greater than that of the second cam 30 between the two extreme positions of the display member 1.
• the present variant provides a reduction of the rotation of the rocker 20 through the gear connection between the rake 27 and the pinion 28 allowing the additional cam 50 to have a larger useful portion of its periphery than that of the second cam 30 of the first variant.
• this construction because of the antagonistic forces it generates, has the additional advantage of preventing the appearance of a game at the level of the gear connection provided between the pinion 28 and the rake 27.
• the stiffness constant of the spring 61 is adjusted so that the contact of the tip 26 of the feeler on the periphery of the first cam 10 is guaranteed at any time, without causing too much friction.
• this geometry makes it possible to arrange the axis of rotation of the rocker in the immediate vicinity of the cam while having the possibility of applying the force of the spring in the vicinity of this same axis.
• the skilled person may choose a different rocker geometry according to his own needs.

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• 2006
  • 2006-03-29 CH CH00516/06A patent/CH698826B1/fr not_active IP Right Cessation
• 2007
  • 2007-03-29 DE DE602007010270T patent/DE602007010270D1/de active Active
  • 2007-03-29 US US12/294,960 patent/US7974156B2/en active Active
  • 2007-03-29 WO PCT/EP2007/053061 patent/WO2007110451A2/fr active Application Filing
  • 2007-03-29 EP EP07727533A patent/EP2010971B1/de not_active Not-in-force
  • 2007-03-29 JP JP2009502103A patent/JP5145323B2/ja not_active Expired - Fee Related
  • 2007-03-29 CN CN2007800160210A patent/CN101438213B/zh not_active Expired - Fee Related

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