Abstract: The device for performing the method for detecting the zero position of a hand of a quartz watch with analogue display enables a beam of light to be generated and directed onto a reflective surface integral with a moving part bearing the hand, the reflected beam to be received on a detector and the position for which the output signal of the detector is maximal to be determined to make it correspond to the zero position of the hand when assembling the watch. This device comprises a source (1) emitting a beam of light (2) and a receiver (3) which intercepts the reflected beam (4) returned by a very reflective area (5). This area is integral with a surface of a moving part (6), for example the wheel bearing the second hand and, depending on the position of this wheel, the reflective surface may occupy a position (5) or an adjacent position (5') staggered by less than one step.

Abstract: This device is specified for a wrist watch, comprising at least one bi-directional electric motor, at least one mechanism coupled to this motor to drive a day disk (12) and a date disk (10), and at least one electronic circuit designed to transmit control impulses to this motor. This mechanism comprises a drive wheel (11) coupled to the motor and two date fingers (14, 15) pivoting respectively on two axes (16, 17) borne by said drive wheel (11) to increment, and decrement respectively, the date disk (10). The drive wheel (11) also bears a control wheel (22) for a day star (13) designed to increment, or respectively decrement, the day disk (12) by means of said day star (13). The control wheel (22) for the day star is concentric with the drive wheel (11) and integral with the latter when it rotates in one direction or the other.

Abstract: The portion of the rim (1) situated between the flanges (2) presents a clearance (3) in the form of an arc of a circle provided between the lateral exterior side and concentric with the center of the case. Another clearance (4), also in the form of an arc of a circle, is provided in the surface of the rim (1) adjacent to the crystal (5) and extends at an angle from the first clearance (3) and on both sides thereof. The edge of the second clearance (4) is located at a distance from the outside edge of the rim (1), thus providing two retaining eyes (4a). The clearances (3, 4) receive a decorative element (6), the upper side of which is adjacent to the lower side of the crystal (5), which prevents it from falling out through the clearance (4).

Abstract: An electronic watch having an electronic circuit arranged to control at least one function of the watch other than the usual functions of time indication, in which the manipulation of a time-setting rod and/or the position of movable elements of the watch at a given moment define the parameters which, alone or in combination, correspond to access codes which are recognized by the electronic circuit for accessing the advanced features. The present invention proposes to control the advanced features of the watch by means of a single time-setting rod. The time-setting rod of the preferred embodiment detects four parameters for determining an entered access code. These parameters are: (1) the position of the time-setting rod; (2) the rotation of the time-setting rod; (3) the direction of rotation of the time-setting rod; and (4) the rotation velocity of the time-setting rod.

Abstract: A process for programming the perpetual calendar of a watch with analog time display is effected using elements incorporated in the watch. The hand of the watch and the position of the hand is used to indicate the steps of the programming. The operation of the stem places the watch in the program mode. If it is required to program three parameters, namely, the number of the year in a four year cycle, the number of the month of the year and the day of the month; and if the watch has a hand setting stem with three positions, each parameter to be programmed is allocated to a position of the stem and the parameters to be programmed are read from the second hand by allocating to the latter real steps corresponding to stopping positions and non allowable steps corresponding to non stopping positions.

Abstract: The chronometer comprises a face (11) having a first sector (14) which bears reference marks (12A) and a second sector (15) bearing reference marks (12B). A single hand is designed to move at a first speed between the starting point M of reference marks (12A) and the final point 30 of these reference marks and at a second speed between the starting point 30 of reference marks (12B) and the final point 0 of these reference marks. The displacement of the hand over the first sector lasts exactly nine minutes and thirty seconds. The displacement of the hand over the second sector lasts thirty seconds. This chronometer is specially designed to control the preparation time preceding the start of regattas.

Abstract: A device for controlling or correcting the readout of the day of the week or date for an analog watch, comprising a crown cogged on the inside and integral with a date or day disk, a bi-directional drive motor and a drive wheel coupled to the drive motor, the drive wheel having two opposite spring-loaded clicks and an arcuate slot in which a fixed stud is engaged, the stud cooperating with the edges of the slot to limit the travel of the drive wheel. The drive mechanism of the date or day disk can thus be recentered automatically after the watch has stopped while simultaneously compensating the rated steps of the motor.

Abstract: A process and apparatus for determining the state of discharge of an electric battery by measuring the voltage drop associated with changes in its internal resistance. According to the process, the battery is periodically connected to a reference load for a brief interval during which the voltage at the terminals of the load is measured. The measured analog voltage is converted to a digital signal which is compared to a number of pre-programmed digital levels to determine the state of change of the battery. The apparatus comprises a commutation component controlled by a logic signal, a reference load, a sampler-and-hold circuit, an analog-to-digital converter and a comparator which can be programmed at n levels. The apparatus compares digital signals corresponding to the voltage at the terminals of the reference load with the n programmed levels of the decoder and a signal is generated indicating the level of the electric battery with respect to the levels programmed into the comparator.

Abstract: An electronic time-counter for diving including a device ensuring its automatic switching on under the action of the water during its immersion and a unique control element manually operable and arranged in such a way that its operation produces the reset to zero of the display device so as enable the diver to measure the intermediary time durations between the beginning and the end of a dive. This counter includes moreover a first memory circuit recording the time which has elapsed between the automatic switching on of the counter at the moment of its immersion and the first operation of the control element. This counter further includes second memory circuit recording the total duration of the dive between the automatic switching on of the counter at the moment of its immersion and its automatic releasing or switching off at the moment of its emersion.

Abstract: A tool for tightening and untightening screw-type bottoms or backs of watch casings in which the spindle by which the bottom is rotated is threaded to a tool stand using the same pitch of thread as that of the threads on the watchcase bottom, so that as the spindle is rotated it is displaced axially by the same amount as the bottom, thereby keeping the tool on the spindle in proper engagement with the bottom of the case.