Abstract: The invention concerns a mechanical or electromechanical dive watch including hour (4) and minute (6) hands, a pressure sensor (42), a depth indicator hand (14) and a depth variation indicator hand (22), the depth indicator hand (14) providing a diver with an indication of the instantaneous value of the depth at which he is situated when diving, the depth variation indicator hand (22) being at that moment locked at zero, the depth indicator hand (14) being locked in turn when the diver reaches a required decompression stop and the depth variation indicator hand (22) being released to indicate to the diver any variations in his depth relative to the decompression stop depth, the depth variation indicator hand (22) then being returned to zero and locked while the depth indicator hand (14) is released and again indicates the exact dive depth when the diver resumes his ascent towards the surface.

Abstract: The invention concerns a mechanical or electromechanical dive watch including hour (4) and minute (6) hands, and a pressure sensor (42), characterized in that it further includes a depth indicator hand (14) and a depth variation indicator hand (22), the depth indicator hand (14) providing the diver with an indication of the instantaneous value of the depth at which he is situated when he is diving, the depth variation indicator hand (22) being at that moment locked at zero, the depth indicator hand (14) being locked in turn when the diver reaches a required decompression stop and the depth variation indicator hand (22) being released to indicate to the diver any variations in his depth relative to the decompression stop depth, the depth variation indicator hand (22) then being returned to zero and locked while the depth indicator hand (14) is released and again indicates the exact dive depth when the diver resumes his ascent towards the surface.

Abstract: A timepiece, includes a Chinese calendar display device indicating lunar date and lunar month, taking account of bissextile months, and: a control lever actuated each day by a drive wheel of the timepiece movement; a lunar month indicator associated with a month star-wheel; a lunar date indicator associated with a date wheel set including a date wheel moved forward one step each day by the control lever, a lunar month length indicator coupled to a selector, having two positions manually controlled and alternately defining two different stop positions for the lever, respectively corresponding to a long month and to a short month, the control lever moves the date wheel forward one extra step at the end of short months; and a month indicator coupled to a bissextile month selector, having two positions manually controlled and that moves the month star—wheel back one step at the start of bissextile months.

Abstract: A timepiece includes a Chinese calendar display device indicating lunar date and lunar month, taking account of bissextile months, and: a control lever actuated each day by a drive wheel of the timepiece movement; a lunar month indicator associated with a month star-wheel; a lunar date indicator associated with a date wheel set including a date wheel moved forward one step each day by the control lever, a lunar month length indicator coupled to a selector, having two positions manually controlled and alternately defining two different stop positions for the lever, respectively corresponding to a long month and to a short month, the control lever moves the date wheel forward one extra step at the end of short months; and a month indicator coupled to a bissextile month selector, having two positions manually controlled and that moves the month star-wheel back one step at the start of bissextile months.

Abstract: Timepiece such as a wristwatch fitted with an alarm mechanism including a member able to produce an alarm signal at a predetermined moment, as well as a control device for providing visual information indicating whether the alarm mechanism is switched on or off, and simultaneously locking or releasing the alarm generator member, characterised in that the control device is activated by means of a push-button.

Abstract: The present invention concerns a timepiece such as, in particular, a wristwatch, including a watch movement, a running equation of time device, as well as a date mechanism, this timepiece having a pair of hour (22) and minute (24) hands which indicate the civil time, and an additional minute hand (28) which indicates the true time, the daily position of the true time minute hand (28) with respect to the civil time minute hand (24) being determined by the position of an equation of time cam (32) driven in rotation at the rate of one revolution per year by a date mechanism, characterized in that the true time minute hand (28) is driven by a differential gear (50) which has for respective power take-off a gear train (52) driving the civil time minute hand (24) and a transmission member which co-operates with the equation of time cam (32) to transmit the pivoting movement of said cam (32) to the input of the differential gear.

Abstract: Timepiece such as a wristwatch fitted with an alarm mechanism including a member able to produce an alarm signal at a predetermined moment, as well as a control device for providing visual information indicating whether the alarm mechanism is switched on or off, and simultaneously locking or releasing the alarm generator member, characterised in that the control device is activated by means of a push-button.

Abstract: The present invention concerns a power reserve indicator device (1) for a manually or automatically wound timepiece, said timepiece including a barrel, a mainspring housed in the barrel and time display elements mechanically coupled to said barrel, said indictor device (1) including a differential gear (10) a first input (8) of which is driven by a winding gear train (6) which meshes with a first driving gear formed by the barrel core, the output (16) of said differential gear (10) driving a display gear train (18) for indicating the reserve of power assured by the number of winding turns of the mainspring, characterised in that the second input (14) of the differential gear (10) is driven by a letting down gear train (12) which meshes with a second driving gear formed by the outer toothing of said barrel or by a wheel and pinion driven by said barrel.

Abstract: The present invention concerns a timepiece such as, in particular, a wristwatch, including a watch movement, a running equation of time device, as well as a date mechanism, this timepiece having a pair of hour (22) and minute (24) hands which indicate the civil time, and an additional minute hand (28) which indicates the true time, the daily position of the true time minute hand (28) with respect to the civil time minute hand (24) being determined by the position of an equation of time cam (32) driven in rotation at the rate of one revolution per year by a date mechanism, characterized in that the true time minute hand (28) is driven by a differential gear (50) which has for respective power take-off a gear train (52) driving the civil time minute hand (24) and a transmission member which co-operates with the equation of time cam (32) to transmit the pivoting movement of said cam (32) to the input of the differential gear.

Abstract: An annual calendar mechanism including a date-disc provided with a first inner toothing including thirty one teeth, and a date drive wheel and pinion, said wheel and pinion including a finger capable of driving said date-disc through one step once a day, characterized in that the date-disc includes a second inner toothing provided for driving, via a gear train, a month-cam carrying at least five teeth, each of these teeth being arranged to be situated, at the end of the months of less than thirty one days, on the path of the beak of a lever and in that said lever carries a correction drive wheel and pinion fitted with a correction finger co-operating with the first or second toothing at the end of the aforecited months to drive the date-disc through one additional step at the end of said months when the lever pivots following the passage of its beak over a tooth of said cam.

Abstract: A date movement for a clockwork movement including a member (8) for indicating the tens having four positions carrying a scale from <<zero>> to <<three>> or from <<one>> to <<three>> plus a blank, provided for effecting one step every ten days, and a member (10) for indicating the units arranged for effecting one step per day, characterised in that the units indicator member (10) can occupy thirty one positions and carries three successive scales from <<zero>> to <<nine>>, one of the three scales, called the modified scale, having an additional <<one>> inserted between its <<zero>> and its <<one>>.

Abstract: The mainspring (3) is coiled inside a barrel at an angle .alpha.=n2.pi. radians. The spring has a rectangular section of a constant width. At least one first portion of the spring extending from the wall (2) of the barrel towards the core (5) has an increasing thickness e selected so that the coiling angle .alpha. times the cubed value of the thickness e has a constant value, namely .alpha..e.sup.3 =constant. One thus obtains, at least in the effective part, namely conventionally the first twenty four hours of operation, a constant force supplied by the barrel and consequently a constant amplitude of the balance.

Abstract: A manually or automatically wound extra-thin watch movement, comprising at least one barrel (3) and in which all the wheel sets are assembled in cantilever on one sole base plate (1) with the help of one ball bearing only (15 to 21). The ratchet (25) is in the form of a drum surrounding the barrel. It is swivelled by its periphery with the help of at least three rollers, each pivoted on a ball bearing, and the barrel (3) is pivoted within the ratchet by means of a ball bearing (23). This design enables reducing to a minimum the energy losses due to friction.

Abstract: In the mechanical selfwinding watch movement with an oscillating winding weight, the winding weight and the spring barrel driving the movement are pivoted coaxially, in the center of the movement, above the winding and the movement gears. The winding weight and the spring barrel have substantially the same thickness and they are on the same level. The spring barrel occupies almost the whole space in the path of the heavy sector of the winding weight. Due to the permissible size of such a spring barrel, the latter is able to store up an energy sufficient to keep the movement running during eight days at least.

Abstract: A chronograph watch comprises a first motor controlled by a quartz resonator coupled to a first simple integrated circuit. This motor drives, through gearing, the time indicating members of the watch. A second motor controlled by a second quartz resonator coupled to a second simple integrated circuit, identical to said first integrated circuit, can be operated at a higher frequency when a switch, which is operable manually by means of a pushbutton and interposed between electrical ground and a terminal of the second integrated circuit, is open. The second motor drives, through further gearing, a chronograph hand coupled to a minute counter and to an hour counter. Thus the chronograph indicates fractions of seconds without the timepiece requiring expensive circuits or having an excessive electrical power consumption.