Abstract: A method and device for controlling a stepping motor having a coil and a rotor with a permanent magnet magnetically coupled to the coil. A drive pulse is applied to the coil each time the rotor has to turn by one step, and a representation of the quantity of mechanical energy supplied by the motor is measured during this drive pulse. The instant when the representation of the mechanical energy passes through its maximum value is detected, and the drive pulse is interrupted at this instant. The method and device increase the operating reliability of the stepping motor.

Abstract: The timepiece includes a timekeeper displaying hours (4) and minutes (5), a receiver for radio broadcast messages capable of being read on a display (7) and a control arrangement (3) including a stem fitted into a crown (10). The stem-crown can be brought into three different axial positions, a first stable drawn-out position in which the timekeeper may be set to the time of day by rotation of the crown, a second stable neutral position in which received messages may be displayed one after the other by rotation of the crown and a third pushed-in unstable position in which the displayed message can be erased or protected.

Abstract: This holder (2) for a replacement battery (12) for a watch, in addition to a housing for holding such battery, includes means (15) for gaining access to the watch battery which is to be exchanged. Accessory thereto, the holder may serve as a key holder and present the advantage of of always being carried by the person wearing the watch. The holder is in two parts: a sheath (17) in which a drawer (18) is fitted, such drawer bearing the replacement battery (12) and an incorporated tool (15) which enables extraction of the exhausted battery from the watch.

Abstract: The finished metallic material of this invention is constituted by an agglomerate of finely divided metallic powder, the grains of which are bonded together by means of an organic substance, the volume of such substance being comprised between 0.5 and 7% of the total volume of the material. In order to obtain said material, the metallic powder is mixed with the organic substance, the mixture is moulded under high pressure and after removal from the mould, the material is heated in order to harden the organic substance. The material is employed to advantage for elements constituting horological articles.

Abstract: This invention concerns a braking arrangement for a gear wheel. The purpose of the invention is to brake the last wheel in a gear train in order to avoid the latter rotating through unequal angular steps. Such purpose is achieved with the help of an element forming a brake (1) fixed onto a first wheel set (2) of a gear train in a manner to be driven in rotation by the latter, such element (1) exhibiting a friction surface (39) at its periphery brought to bear elastically onto a second wheel set (6) meshing with the first so as to brake such second wheel set (6). The invention is more especially applied to horological and chronograph gearing.

Abstract: The present invention relates to a timepiece of the electromechanical type.This invention has a movement provided with control means such as an electronic circuit connected with a resonator, a source of electrical energy, and in particular battery, and electrical connection means to connect this battery to the control means via the intermediary of a first supply path wherein the electrical connection means also supply a second parallel supply path which is capable of providing a substantially permanent and reliable connection between at least one of the poles of the battery and the control means.This invention has applications in any electromechanical timepiece such as, for example, a wristwatch.

Abstract: The control device is intended to supply a stepping motor with driving pulses during which the mean value of the voltage applied to the coil of this motor is independent from the voltage of the power supply source of the device.For that purpose, the control device comprises a driving circuit which connects or disconnects the coil of the motor to or from the power supply source when a control signal has a first state or a second state respectively, and a control circuit which produces this control signal with its first state or its second state in dependency on the difference between a reference voltage and the voltage across the coil.

Abstract: The invention concerns a timepiece movement having a baseplate (20), a motor (22), an oscillating system (24), driving elements (26, 27) intended to drive indicating elements (16, 18), a gear train (28) having at least one wheel coupling the driving elements (26, 27) to the motor (22), the motion of the gear train being regulated by the oscillating system (24), the timepiece movement being characterized in that it further includes a support element (50) for at least one of the elements other than the baseplate constituting the movement, the support element (50) being driven in rotation in the vicinity of the edge of the baseplate by a wheel (48) of the gear train.

Abstract: A watch movement is a combination of a chronograph module and a motor module, the motor module comprising a third wheel, a first power take off composed of a toothed wheel fixed to the cannon-pinion and a second power take off composed of a pinion fixed to the seconds axle in the center, the chronograph module having a chronograph hand, a hand for the minute counter and a hand for the hour counter. This watch movement also has a third power take off composed of a wheel fixed to the third wheel, these three power take offs being accessible from the same side by the upper face of the motor module and the chronograph module being placed against said upper face of the motor module, and in that the hand of the chronograph, the hand of the minute counter and the hand of the hour counter are driven respectively and in independent manner by said second, third and first power take offs.

Abstract: An axial flux electromagnetic micromotor is described. The micromotor has a stator, a rotor which is pivotally mounted in relation to the stator about an axis of rotation, the rotor having at least one pair of magnetic poles producing in an air gap a magnetic field substantially parallel to the axis of rotation and at least one substantially planar coil situated in the air gap in such a way as to intercept a flux created by the field, this micromotor having an air gap that is solely delimited by the rotor. The micromotor can be used to drive a mechanism.

Abstract: The invention concerns an electromagnetic micromotor. Such micromotor includes a rotor constituted by a permanent magnet (52) partially embedded in an overmolding (54) formed from plastic material and which is provided with coupling means to a driven mechanism, a cage (60) including a bottom and a cover and intended to be engaged in the interior of a stator while the rotor is mounted for free rotation in the cage, and rotation guide means for the rotor (50) in the cage (60), such micromotor being characterized in that the rotation guide means are constituted, on the one hand, by two housings (74, 76) coaxially arranged in the overmolding (54), and on the other hand, by two spindles (78, 80) respectively integral with the bottom and the cover of the cage and intended to be accommodated respectively in one of these housings. Such micromotor is intended to equip timepiece movements of very small dimensions, for instance for ladies' watches.

Abstract: This wristwatch includes a watch case (1), time displaying means (3, 4) and an energization cell (5). The cell can be fitted into a lateral opening (10) giving access to a housing formed in the watch case. The cell is carried by a drawer (6) which is fixed to the end of one of the strands (7) of the bracelet. Locking means (11) maintain the drawer attached to the watch case once said drawer is introduced into the housing in the watch case.

Abstract: An analog timepiece in which the hands are in a given set position, for example superimposed at 12 hrs, to indicate a time reference, for example noon. This timepiece has adjustment means to change the said time reference in relation to the dial. Thus, for example, reorientating the said time reference through 180.degree. to 6.00 hrs, a wristwatch designed to be worn on the left wrist can be converted into a wristwatch designed to be worn on the right wrist.

Abstract: The timepiece of this invention comprises an electromagnetic motor (100) the stator (2) of which is flat and at least partially covered by a reinforcement plate (68) of non-magnetic material or, if need be, of very low magnetic permeability which has been attached to it, preferably by welding, prior to subjecting it in bulk along with others, to reheating thereby to protect it during such operation against the risk of deformation or breakage which would render it thereafter unusable. In conformity with the invention and to avoid such plate becoming a useless extra part taking up space in the timepiece, it includes means which enable it to form at the same time another element of the timepiece. Such element may be for instance a trigger piece jumper spring (72) which cooperates with a trigger piece (212) in order to define stable positions of a manual control stem (184) which may be axially displaced.

Abstract: A wristwatch for receiving messages broadcast by radio, includes the assembly of a movement, a caseband (4) and a back cover (44). The movement comprises a baseplate (13) receiving: a display means (1, 2), a first power cell for controlling the time display a message display cell (16), a first crystal (21), electronic circuits (18), a casing (24) for receiving a second power cell (25) and an antenna formed by a coil including turns (23) wound around the movement and bearing on the first crystal and on the casing. The caseband includes a second crystal (41) and caps the upper part of the movement. The back cover overlays the lower part of the movement and is provided with a side opening (47) giving access to the second power cell to enable changing thereof.

Abstract: A resonator has a parallelepipedal bar of a piezoelectric material designed to vibrate in an extension mode, and suspension means of said bar which form a single, integral part with the latter and which are only connected to one of its lateral faces. This arrangement makes it possible to reduce the number of parasitic vibration modes which could couple to the main mode as well as coupling between these modes, and hence variations as a function of the temperature in the characteristics of the resonator, notably in its quality factor.

Abstract: This invention concerns an electromagnetic motor. Such motor includes: a rotor (1) comprises a bipolar permanent magnet, a stator (2) provided with a peripheral stator portion (14) forming a low reluctance magnetic circuit (CM) and an interior or central stator portion (12) on which are arranged n branches including first ends forming polar expansions and second or free ends, and windings (22, 24, 26) adapted to generate a magnetic flux, such motor being characterized in that the windings (22, 24, 26) are mounted on and are respectively anchored at least to the second or free ends of the branches. Such motor is applied for example to operation in a three-phase energization mode.

Abstract: A fly-back chronograph provided with a stop-start control for the fly-back hand is provided. The control does not require careful and frequent adjustment and avoids premature wear of the fly-back wheel parts. The control device has fly-back pincer, a fly-back wheel disposed between the free extremities of the two branches of the said pincer, two fixed reaction members against which a connecting member between the two branches of the pincer bear and deformation means creating a force acting against the said reaction members on the said portion of the connecting member in order to deform it.

Abstract: A timepiece including a decorative pattern (30) rotating with the arbor (8) for one of the hands under a first crystal (1). In order to avoid permanent deformation of the arbor brought about by shocks, the decorative pattern is surrounded by a protective wall (11) which may be in the form of a bore in a second crystal (2) located between the first crystal and the dial (5) of the watch.