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
  • G04B43/00—Protecting clockworks by shields or other means against external influences, e.g. magnetic fields
  • G04B43/002—Component shock protection arrangements
• • G—PHYSICS
  • G04—HOROLOGY
  • G04F—TIME-INTERVAL MEASURING
  • G04F7/00—Apparatus for measuring unknown time intervals by non-electric means
  • G04F7/04—Apparatus for measuring unknown time intervals by non-electric means using a mechanical oscillator
  • G04F7/08—Watches or clocks with stop devices, e.g. chronograph
  • G04F7/0823—Watches or clocks with stop devices, e.g. chronograph with couplings between the chronograph mechanism and the base movement
  • G04F7/0828—Watches or clocks with stop devices, e.g. chronograph with couplings between the chronograph mechanism and the base movement acting in the plane of the movement

Definitions

• the present invention relates to chronograph mechanisms, of the type comprising:
• a clutch wheel capable of occupying two positions and intended to connect the chronograph train to the finishing train in one of these positions
• a clutch lever provided with a stopper and intended to ensure the movement of the clutch wheel, between its first position in which the mechanism is in operation, and its second position in which the mechanism is inoperative
• a clutch member intended to move the clutch wheel between its first position in which the mechanism is in operation and its second position in which the mechanism is inoperative
• a cam intended to cooperate with the clutch member to define the first and second positions of the clutch wheel
• a control lever provided with a control member actuating the cam and, by it, the member clutch to move the clutch wheel from one to the other position
• a mechanism of this type is, for example, described in the clock theory book of Chs-A. Reymondin et al., Page 232 (Federation of Technical Schools of Switzerland, 1998, ISBN 2-940025-10-X).
• the cam is a column wheel.
• the clutch member and a rocker carrying a clutch wheel intended to kinematically connect the gear train of the watch, which rotates continuously, with the chronograph train, which rotates only on demand. More specifically, the clutch wheel is engaged or not engaged depending on whether the lever occupies its first position or its second position.
• the end of the rocker is provided with a nose forming a stop and which, in cooperation with the columns of the column wheel, depending on whether it is facing a vacuum or whether it rests on a solid column wheel, defines the first and second positions, under the effect of the rocker spring.
• the support springs responsible for keeping the various organs in place during their operation it sometimes happens that during a measurement, the mechanism being in its first position, a sudden movement of the wearer or a violent shock causes a jump in the clutch lever.
• the driving of the chronograph train is then interrupted for an instant, which distorts the measurement.
• the present invention implements means to alleviate the drawback explained above.
• the mechanism is characterized in that the control lever comprises a lock and the clutch member is provided with a crampon cooperating with the lock when the clutch wheel occupies its first position, all so the rocker is prevented from moving under the impact of a shock when the clutch wheel is engaged with the chronograph train.
• the clutch member is a rocker provided with a stop cooperating with the cam
• the cam is a column wheel which comprises:
• control member comprises a hook secured to the control lever and a stopper nose arranged to cooperate respectively with the ratchet and with the columns of the column wheel.
• the hook is arranged so that the lock has released the clamp before a column cooperates with the nose. It is also advantageous that, in the mechanism and according to the invention, the control lever, the ratchet, the latch and the crampon are arranged so that, when the clutch wheel is in its first position, the lever control cooperates with the rocker by means of the latch which bears against the crampon.
• the chronograph mechanism according to the invention is further characterized in that the sum of the thicknesses of the latch and of the crampon is less than or equal to the length of the arc described by the end of the clutch lever between the positions that it occupies when the clutch wheel is in its first or second position.
• FIGS. 1 and 2 are top views of a watch movement provided with a chronograph mechanism respectively in the engaged position. and in the disengaged position.
• the movement shown in the drawing comprises a plate 10 which carries the essential elements of the chronograph mechanism, namely a clutch device comprising:
• a chronograph driving wheel 12 integral in rotation with the seconds mobile of the finishing train of the watch, which is located on the side of the plate 10 opposite to that shown in the drawing,
• a clutch lever pivotally mounted on the plate, carrying the clutch wheel 14 and provided, at one of its ends, with a nose 18 forming a stopper and intended to define the positions of the clutch wheel, and a crampon 20 ensuring a locking of the rocker 16, as will be explained later, and
• a chronograph mobile 22 placed in the center of the movement and whether or not engaged with the clutch wheel 14, depending on whether the wheel 14 occupies its first or second position, and a device for controlling the clutch device, which comprises:
• control lever 26 pivotally mounted on the frame, controlled by a pusher not shown in the drawing and secured to the watch case,
• control hook 28 pivotally mounted on the control lever and arranged to cooperate with the column wheel 24, as will be explained below,
• the lever 16 pivots at its end opposite to that comprising the nose 18 on an eccentric secured to the plate 10, not shown because it is outside the scope of the drawing.
• the rocker 16 is subjected to a positioning torque by a rocker spring also disposed outside the scope of the drawing. In the position shown in FIG. 1, it bears against an eccentric 31, the nose 18 being engaged between two columns 40.
• the control lever 26 pivots on a tenon, and is held in place by a screw 32 fixed in a tapped hole in the tenon.
• One of its ends carries, pivotally mounted, the control hook 28, while the other end is arranged, in a conventional manner, to cooperate with the control push-button. This possible pivoting of the hook 28, combined with the pressure of the hook spring 30, maintaining it in a position enabling it to cooperate with the column wheel 24.
• the control lever 26 carries a pin 33.
• an arm 34 is fixed to the upper face of the control lever 26 by means of a screw 35 engaged in a hole made in its middle part.
• a screw 35 engaged in a hole made in its middle part.
• One of its ends is provided with a lock 36 arranged to cooperate with the crampon 20.
• the other end forms a stop 37, which bears against the pin 33.
• the column wheel 24 is made in one piece and consists of a Breguet toothing forming a ratchet 38 and of columns 40 arranged perpendicularly and concentrically to the toothing, the angular pitch of the columns being twice that of the Breguet toothing . It is positioned by the jumper spring 25 engaged on the Breguet toothing of the ratchet 38. It governs the interaction between the control and clutch devices.
• the nose 18 of the lever is engaged in one of the spaces between the columns 40.
• the clutch wheel 14 is thus in its first position and drives the chronograph mobile 22
• the latch 36 spans the crampon 20.
• the length of the arm 26, as well as the shape of the crampon 20 and of the latch 36 are chosen so that the arm 34 comes to bear on the lever 16 by the intermediate the blanks of the crampon 20 and the latch 36.
• the arm 34 being integral with the control lever 26, which is positioned by the spring 30, it follows that the latch 36 and the crampon 20 are in intimate contact with each other. 'other and block the rocker 16 in its position where the wheel 14 is engaged with the wheel 22, even if a shock tends to move it.
• control hook 28 and the ratchet 38 do not exactly coincide, the parts having a play two together. More specifically, the control lever 26 must pivot by an angle ⁇ 1 so that the hook 28 traverses the lost path existing between it and the ratchet 38, then by an angle ⁇ 2 so that the column wheel 24 rotates until that a column, identified by the letter a, comes into contact with the nose 18. To ensure optimum operation, the lever 16 must not be set in motion until after the latch 36 has released the clamp 20.
• the mechanism thus described operates in the following manner.
• a pressure exerted on the push-button makes the lever 26 rotate clockwise and, with it, the arm 34 and the control hook 28.
• the hook 28 takes the game of the lost path, then it drives the column wheel 24 until the column 40a comes into contact with the nose 18, lever 26 thus traversing the angle ⁇ .
• the latch 36, part of the arm 34 lifts and moves away from the crampon 20, thus releasing the movement of the clutch lever 16.
• the column 40a in contact with the nose 18, the raises, thereby pivoting the clutch lever 16 so that the clutch wheel 14 disengages from the chronograph mobile 22.
• the column 40a thus acts on the nose 18 of the clutch lever 16 to rotate it in the space left free by the latch 36.
• the column wheel 24 When the lever 26 has reached the end of its travel, that is to say when the control hook 28 has driven the column wheel 22 with a pitch of the Breguet teeth, the column wheel 24 is in a position such that the column 40a maintains the rocker 16 so that the wheel 14 is disengaged from the wheel 22.
• the control lever 26 When the push button is released, the control lever 26 returns to its initial position under the effect of the jumper spring 30, the control hook 28 jumping on a ratchet tooth 38 while the lock 36 passes from the other side of the crampon 24.
• the nose 18 of the clutch lever remains in abutment on the column 40a, defining the second position of the clutch wheel 14 in which the chronograph mobile is no longer driven.
• the lever begins by taking the play of the lost path, then drives the wheel. with columns 24 of a pitch of the Breguet toothing, so that the nose 18 leaves the support of the column 40a and falls into the space between two columns.
• the lever 26 is in a position such that the latch 36 is outside the space traversed by the crampon 20.
• the clutch lever 16 can therefore pivot freely until it meets the eccentric 31, the nose 18 thus being again engaged between two columns 40.
• control lever 26 When the push button is released, the control lever 26 returns to its initial position, as shown in FIG. 1, the control hook 28 jumping a tooth of the ratchet 38 while moving back and the lock 36 spanning the crampon 20. The lever 22 has thus returned to its first position, in which the clutch wheel 14 is engaged with the clutch mobile 22.
• a chronograph locking system is produced which, by the cooperation of a lock secured to the control lever and of a crampon surmounting the clutch lever, prevents the lever 16 from leaving its clutch position inadvertently. Operational safety is thus significantly improved.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Measurement Of Unknown Time Intervals (AREA)

Priority Applications (1)

Applications Claiming Priority (4)

Publications (2)

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ID=8184155

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• 2001
  • 2001-09-24 EP EP01810930A patent/EP1296205A1/de not_active Withdrawn
• 2002
  • 2002-09-06 DE DE60226256T patent/DE60226256T2/de not_active Expired - Lifetime
  • 2002-09-06 WO PCT/CH2002/000487 patent/WO2003027778A2/fr not_active Ceased
  • 2002-09-06 JP JP2003531261A patent/JP4235106B2/ja not_active Expired - Fee Related
  • 2002-09-06 US US10/490,615 patent/US6926438B2/en not_active Expired - Lifetime
  • 2002-09-06 EP EP02758029A patent/EP1430367B1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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