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
  • G04B19/06—Dials
  • G04B19/08—Geometrical arrangement of the graduations
  • G04B19/082—Geometrical arrangement of the graduations varying from the normal closed scale

Definitions

• the present invention relates to the field of mechanical watchmaking. It relates, more particularly, to a drive mechanism of at least a first and a second circular display member composed of: - a drive shaft, intended to be rotated, a first transmission device of the movement of rotating the drive shaft to the first circular display member, a second device for transmitting the rotational movement of the drive shaft to the second circular display member.
• the present invention also relates to a retrograde type display mechanism, comprising at least two circular display members each rotating in a single direction but giving the illusion of a retrograde display.
• a retrograde type display mechanism comprising at least two circular display members each rotating in a single direction but giving the illusion of a retrograde display.
• retrograde type display systems are well known to those skilled in the art.
• a first type of retrograde display which will be called “true” retrograde, comprises a single display member moving in one direction at the desired display speed to the maximum value to be displayed and returning to its position. initially by running in the opposite direction.
• the return force of the spring is used to return the display member to its original position.
• the system disclosed in the patent CH666591 proposes to use a spiral cam, with a spring for maintaining a probe integral with the needle in contact with the cam.
• a spring for maintaining a probe integral with the needle in contact with the cam.
• retrograde devices "real" instantaneous return, the fact of having to arm a spring has a direct negative impact on the power consumption and therefore on the power reserve of the watch and the amplitude of the balance of the movement of the watch.
• a second type of retrograde display which will be called retrograde "false” includes a single display member always moving in the same direction but giving the illusion of an instant return to its position. origin.
• a mask is applied in front of the needles to hide them when they are in a first half of the dial and leave them visible when they are in the other half.
• the opposite needle is hidden during its return phase (consisting of ending its rotation, in the same direction but in the other half of the dial).
• the visible needle reaches the maximum value to display, it is hidden by the mask.
• the opposite needle then becomes visible and starts its active phase from the minimum value to display.
• Such systems can be qualified as "false" retrograde, since on the one hand, the display member always rotates in the same direction of rotation and, on the other hand, there is no visible return phase.
• any retrograde system "true” instantaneous return and in any retrograde system “false” based on the masking of the display member during its return to the original position, only the phase to go of the display member may be used to display information at the desired speed.
• the document CH694175 has a retrograde display "true", the return phase of the display member is not instantaneous. This return phase occurs at a speed identical to that of the forward phase, thus making it possible to display the information at the same speed during a forward phase and during a return phase of the same display unit, by the use of a heart-shaped cam.
• the number of parts used is relatively small, but it requires the use of a cam inducing damaging friction and whose manufacture must to be very precise, as well as the use of a support spring on the cam, energy consumer, disrupting the amplitude of the balance. Disclosure of the invention
• the present invention aims to provide a retrograde type of display system without the disadvantages above.
• the invention more particularly relates to a drive mechanism of two circular display members as described above, wherein the two display members are coaxially placed and rotate in directions. opposite and at equal absolute angular velocities.
• the present invention also relates to a timepiece using the aforementioned mechanism, for which each of the display members comprises N arms. This timepiece further comprises a dial at least partially full disposed above the mechanism and display members, wherein is cut a window forming an opening of an angle of 1807N, the center of which coincides with the axis of rotation of the display members.
• the display members are arranged in such a way that only one of the arms of one of the two aforementioned display members is always visible in the window.
• one of the arms of the display member will go through the entire window in one direction of travel until it reaches the edge of the window, then one of the arms of the other display member will go through the entire window in the other direction of travel.
• FIG. 1 is a view from above of a possible embodiment of the drive mechanism of the display members
• FIG. 2 is a sectional view of the mechanism shown in FIG. 1
• FIG. 3 is a view from above of another possible embodiment of the drive mechanism of the display members
• FIG. 5 shows a display device, in different operating phases, on which only the dial and the display members are shown
• FIG. 6 shows a variant of the display mechanism, on which only the portion located inside a wicket made in the dial is shown.
• a mobile frame not shown, which can be conventionally composed of plates or bridges.
• FIGS. 1 and 2 The mechanism as described in FIGS. 1 and 2 is composed of the following elements:
• a second device for transmitting the movement of the drive shaft 1 to a second display member comprising:
• the drive shaft 1 is driven in the clockwise direction by a movement not shown.
• the wheel 2 thus rotates also in the clockwise direction, and rotates the pinion 4 in the counterclockwise direction.
• the wheel 3 therefore rotates also clockwise, and rotates the pinion 5 in the counterclockwise direction.
• the wheel 6, secured to the pinion 5, rotates counter-clockwise and rotates the pinion 7 clockwise.
• the coaxial pinions 4 and 7 are therefore "counter-rotating", that is to say that they rotate in opposite directions. Either zi the number of teeth of the pinion or the wheel i and vi the angular velocity of the wheel or pinion i, the angular velocities of the wheels or gears are as follows:
• a drive shaft 1 itself acting as a device for transmitting the rotational movement to a first display member, a device for transmitting the movement of the drive shaft
• a second display member comprising: a first wheel 2, mounted to rotate with the drive shaft 1, a first gear 3, driven by the first wheel 2, a second wheel 4, integral with rotation of the first pinion 3, a second pinion 5, driven by the second wheel 4, and a third pinion 6, driven by the second pinion 5 and coaxial with the drive pin 1.
• a drive axis 1 itself acting as a device for transmitting the rotational movement to a first display member, a device for transmitting the movement of the drive shaft 1, to a second member display, comprising: a first wheel 2, mounted integral in rotation with the drive shaft 1, - a pinion 3, driven by the first wheel 2, and whose axis of rotation is perpendicular to the axis of rotation of the first wheel 2, a second wheel 4, driven by the pinion 3 and coaxial with the drive shaft 1.
• the wheels 2 and 4 and the pinion 3 are provided with bevel gears.
• FIGS. 1 and 2 may be used as shown in FIG. 5 in a display mechanism. Only the axis of rotation of the coaxial and counter-rotating elements is represented in the center of the movement.
• a circular display member 12 and 13 On each of the two coaxial and counter-rotating elements (pinions 4 and 7 for the mechanism of Figure 1, drive shaft 1 and pinion 6 for the mechanism of Figure 3, drive shaft 1 and wheel 4 for the mechanism of Figure 4), is mounted a circular display member 12 and 13 to N equi-distributed arms around the axis.
• a circular display member is defined as a needle-like or disk-type display means for rotating about a fixed axis.
• the arms may be, for example, needles mounted on an axis or indexes drawn on a transparent disk.
• N 3 and each arm 12a, 12b,
• a dial 10 provided with a window 11, is applied in front of the display members 12 and 13, that is to say between the window of the watch and the display members. It is partially full, that is to say, it covers the area swept by the display members 12 and 13 with the exception of an area located opposite the window 11.
• the window 11 is an annular sector whose edges are oriented radially with reference to the axis of rotation of the display members 12 and 13.
• the display members 12 and 13 are arranged in such a way that only one of the arms 12a, 12b, 12c, 13a, 13b and 13c of one of the two display members is always visible in the window. 11. To do this, the two display members 12 and 13 are superimposed when they are at the edge of the wicket
• the needle 13a, 13b or 13c will in turn go through the entire aperture, at a speed identical to that of the needle 12a, 12b or 12c rotating clockwise, but in the opposite direction (Figure 5d).
• the counter-clockwise hand will also rotate 1807N (60 ° for the example), until it is at the edge of the window 11, and one of the needles 12a, 12b or 12c turning clockwise becomes visible. We then return to the situation of Figure 5a.
• a variant of the invention consists in differentiating the shape, the color and / or the dimension of the arms of the display members, in order to allow the user to instantly evaluate the value displayed when the Visible display member moves clockwise or counterclockwise.
• large needles for example, with reference to Figure 6, large needles
• One, 14a, is visible in Figure 6a) can be mounted on one of the display members and small needles (one, 15a, is visible in Figure 6b) can be mounted on the other display device.
• the graduations applied opposite the large needles are different from those applied opposite the small needles, in order to benefit from an accurate reading when the visible display member rotates clockwise or counterclockwise.
• the present invention makes it possible to achieve a movement giving the perfect illusion of being retrograde, without requiring complex kinematics to drive the same display member in two directions. It also allows a more interesting information display than a "false" retrograde. In addition, the useful display of information in two opposite directions of movement is aesthetic.
• the elements necessary for the implementation of this invention are limited to wheels, sprockets, display members and a perforated dial.
• the proposed mechanism is thus very simple to implement by the skilled person, in contrast to a "true" retrograde movement.
• the use of wheels and pinions advantageously limits the energy losses, while allowing to position the display members with great precision.

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• Physics & Mathematics (AREA)
• Geometry (AREA)
• General Physics & Mathematics (AREA)
• Electromechanical Clocks (AREA)

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Cited By (1)

Families Citing this family (3)

Citations (2)

• 2008
  • 2008-07-15 CH CH10952008A patent/CH699117B1/fr not_active IP Right Cessation
• 2009
  • 2009-05-29 EP EP09797442A patent/EP2300881A1/de not_active Withdrawn
  • 2009-05-29 WO PCT/EP2009/056608 patent/WO2010006835A1/fr active Application Filing

Patent Citations (2)

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