US3604201A - Method of driving the gearing of an electronic timepiece and an electronic timepiece for implementing said method - Google Patents

Method of driving the gearing of an electronic timepiece and an electronic timepiece for implementing said method Download PDF

Info

Publication number
US3604201A
US3604201A US838422A US3604201DA US3604201A US 3604201 A US3604201 A US 3604201A US 838422 A US838422 A US 838422A US 3604201D A US3604201D A US 3604201DA US 3604201 A US3604201 A US 3604201A
Authority
US
United States
Prior art keywords
impact
gear
armature
tooth
timepiece
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US838422A
Other languages
English (en)
Inventor
Peter Dome
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
SOC SUISSE POUR L'INDUSTRIE HORLOGERE SA
SUISSE POUR L IND HORLOGERE SA
Original Assignee
SUISSE POUR L IND HORLOGERE SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by SUISSE POUR L IND HORLOGERE SA filed Critical SUISSE POUR L IND HORLOGERE SA
Application granted granted Critical
Publication of US3604201A publication Critical patent/US3604201A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • G04B11/00—Click devices; Stop clicks; Clutches
    • G04B11/02—Devices allowing the motion of a rotatable part in only one direction
    • G04B11/04—Pawl constructions therefor, e.g. pawl secured to an oscillating member actuating a ratchet
    • G—PHYSICS
    • G04—HOROLOGY
    • G04C—ELECTROMECHANICAL CLOCKS OR WATCHES
    • G04C13/00—Driving mechanisms for clocks by primary clocks
    • G04C13/08—Secondary clocks actuated intermittently
    • G04C13/10—Secondary clocks actuated intermittently by electromechanical step advancing mechanisms
    • G—PHYSICS
    • G04—HOROLOGY
    • G04C—ELECTROMECHANICAL CLOCKS OR WATCHES
    • G04C3/00—Electromechanical clocks or watches independent of other time-pieces and in which the movement is maintained by electric means

Definitions

  • An electronic timepiece comprises a device for indicating the time, which device includes a gear train and a time indicator controlled by said gear train, an electronic circuit which produces periodic signals of a predetermined frequency and an electromechanical transducer for driving said device, which transducer is controlled by the signals produced by the said circuit; the transducer incorporates a member which swings periodically and at the frequency of said signals, between two limiting positions in order, at least once during the course of two successive swings, to strike successively each tooth of a gear in the said gear train; means are provided in order to limit to a predetermined value the angular displacement of the gear as a consequence of each impact.
  • PATENTED SEP 4 I971 SHEET 1 OF 3 PATENTEDSEPMIB nowadays 3 04201 sum 2 or 3 PATENIEusEPmsn 3,604,201 sum 3 or 3 METHOD OF DRIVING THE GEARING OF AN ELECTRONIC TIMEPIECE AND.
  • the reliability of operation of the transducer shouldbe relatively high'if errors in the time display produced: by said transducer, are not to cancel out the benefits derived from the use of a particularly accurate time base the transducer should be insensitive to external disturbances to which the timepiece may be subjected (shocks, magnetic fields, etc.).
  • the object of the present invention comprises a methodof driving the gear train of an electronic: timepiece, and. also an electronic timepiece: for implementing said method, by means of which it is possible to obtain a time display or. indication which satisfies the above conditions.
  • This method is characterized in that each toothof. one of the gears of the gear train. successively receives an impact. and of that the angular displacement. in the gear, asaconsequence of each impact is limited to apredetermined value.
  • the electronic timepiece for implementing. said. method comprises a device for indicating the time,'whiclr device includes a gear train and a.time. indicator controlled by said. gear train, an electronic circuit producing: periodic. signals of a predetermined. frequency, and an electromechanical transducer for driving said device, which transducer is controlled by the signals produced. by said circuit, wherein saidtransducer incorporates a member which swings periodically, at the frequency of said signals, between: two limiting positions in order, at least onceduringthe course of two successive swings, to strike successively each tooth of a gear in the. gear train, and meansbeingprovided in orderto limitto apredetermined value the angular displacement of the gear asaconsequence of each impact;
  • The; attached drawing illustrates byway of example an. em.- bodiment of an electronic timepiece for implementing: the method formingthe object of the present invention:
  • FIG. 1 is a schematic view showing part of the-elements of said timepiece
  • F lG. 2 is. an elevational view
  • FIGS. 3, 4', 5 and6 are. detailed views illustrating various phases of operation of an electromechanicalatransducer of the kind fitted to the timepiece of; FIG. 1;;
  • FIGS. 7 and 8 are. explanatory diagrams.
  • H6. 9 is a. detailed. view of a. modification. of'one of thetimepiece elements.
  • the electronictimepiece-illustrated'in the.drawing:(FlGS; I and 2) comprises ahigh-precision oscillatorB,.forexamplea crystal-controlled oscillator: producing. a periodic highfrequency. signal, an electronicscaler D..- capable of dividing: the frequency of'saidisignal, for example down'toa valueot 1' Hz., and a circuit: ER: controlled by said. scal'erantt'designed to supply periodic pulses; to an electromechanical transducer in order to drive the second' wheel S of a-gear trainschematically represented by the. axis A. in order to controlthe hands H of the timepiece.
  • ahigh-precision oscillatorB forexamplea crystal-controlled oscillator: producing. a periodic highfrequency. signal
  • an electronicscaler D..- capable of dividing: the frequency of'saidisignal, for example down'toa valueot 1' Hz.
  • ER controlled by said. scal'
  • Thistransducer comprises ananchor-shaped movinggarmature 1' keyed" to a. spindle: 2. which ispitvotedat each: end in. jewels 3xands4. illustrated. schematically. in the drawing, said; spindle, carrying. two. hubs. 5' and. 6: for the attachment; or two spiral springs 7 and 8, and arm 9. These hubs are made, the first, of metal.and,.the second, of electrical-insulating material.
  • Each magnet comprises two pole pieces Il a-and l-lb'( FIG. 1) made of ferromagnetic materialrhavinga very high coercive field strength, the pole pieces beingconnected to one another by ayoke 1100f. magnetizable material havinga low coercive field strength and high permeability:
  • the electromechanical transducer described is of the monostablekind and its armature l is biased'into the position. illustrated in FIG. 1, by thetwo spiral springs 7 and 8.
  • the magnets 11' and 12 are positioned so that, talking into account. their dimensions and in particular the cross-sectional. area of their pole pieces, the turns of the coil are intersected by a maximum magnetic flux over the whole extent of the angular travel of the armature 1.
  • This flux is, moreover, particularly strong in view of the fact that the magnets 11 and IZ are for the most part made-of material having a high magnetic energy and a high coercive field strength, and that the ratio of the length of the magnets to the width of the airgap within which the coil moves, is relatively large.
  • spiral springsT and 8 are coiled in opposite directions and their external extremities, secured by conventional means to a balance cock (not shown) areconnected electrically, in the. case of the coil spring 7, to the-circuit ER, and in the case ofthe coil springr8, to earth, while theje wel bearingsjand 4 are assembled in insulating housings which have not been shown.
  • the hubS to'which the-coil spring 7" is attached is made of metaland. is secured to the spindle Z-andthehub G isv made of. an insulating material: so: that there is no-electrical connection-between the-spiral'spring7 andthe spiral spring 8-, the pulses produced by thecircuitER are supplied tothe coil 10': through the spring 7 andthen': pass to earth through the spring8;
  • the arm 9 is designed to limit. the pivoting movement. of the armature by cooperation with'twostops Band 14 secured to thebridge on thebackingplatetnotshown), the stop filming the exit one, againstwhichithe arm 9-- abuts when-the armature L. is-i'n the rest condition, and. the stop 1 3 beingthe entry one, againstwhich thearm-strikeswhen ltis-swung in the direction F atthesame time. as the-armature 1: (H6. 1).
  • thespiral springs 7 and 8 are lightly loaded when the various moving elements of the transducerare in the position illustratedin FIG. 1 so that the arm 9 isappliedlightly against thestoplAa
  • the drivingof the seconds wheelor gear Si of themovement is produced-exclusively by'the' alternate striking of the pallets 1aand.
  • This drive system is particularly relevant to the case where energy transmission is to be effected with maximum efficiency, and in particular where the amount of energy which can be supplied to the coil with each pulse from the circuit ER, is small.
  • this method of driving by a single mechanical impulse overcomes all the defects and drawbacks traditionally associated with drive systems which employ friction between components, Le. a quantity the value of which varies very widely and depends upon the condition of the surfaces involved and upon their changing characteristics with time and wear etc.
  • the transmission of energy by the striking of a driving element against a driven element is determined exclusively by the geometrical dimensions of the moving parts and by the respective moving masses.
  • losses involved in the transmission of energy by impact are concerned, those skilled in the art will understand that these depend primarily upon the elastic properties of the materials directly involved in said transmission, and not upon the mechanical condition of the surfaces which come into contact with one another. In any case, if this surface condition was wrong after commencement of energy transmission by impact, it will improve very rapidly by consequence of repeated hammer blows between the surfaces involved, so that the energy transmission factor between drive element and driven element will be improved likewise.
  • the efficiency with which said energy transmission takes place achieves a maximum only when the impact takes place in a direction which is tangential, at the point of impact, to the trajectory which is followed, after the impact, by that part of the said element which receives the impact.
  • the second moving body is a toothed wheel and accordingly said trajectory will be circular.
  • the position of the center of pivoting of the armature 1, the length of those arms of said armature which carry the pallets 1a and 1b, and the angular position of each pallet on its respective arm, have accordingly been chosen so that in the position of approach, each pallet is directed towards the center of pivoting of the wheel S when it hits said wheel.
  • the end of the pallet is profiled in order to make an angle of 45 with the tangent to the circular trajectory followed by the different teeth of the wheel S.
  • the efficiency of the impulse driving system employed in respect of the gearing system of the timepiece, the impulse being applied tothe seconds wheel S (FIG. 1 and FIG. 2) by the pallets la and 11; of the transducer armature, can be defined in terms of the ratio of the kinetic energy stored by the gear train and by thedndicating hands of the timepiece, after the impact, to that-stored by the moving part of the electromechanical transducer prior to said impact, viz:
  • 6 is the moment of inertia of the moving part of the transducer, that is to say the assembly comprising the spindle 2, the hubs 5 and 6, the coil springs 7 and 8, the armature 1 and the coil 10;
  • w is the angular velocity of said arrangement at the time of impact of the pallet in against a tooth of the wheel S;
  • k is the recovery" coefficient which can have a value somewhere between 0 and l and is defined by the ratio of the velocity reached by an element of a given material after having fallen onto a fixed substrate likewise made of a given material but possibly of different nature, and the velocity which said same element had prior to hitting the substrate;
  • r is the effective radius of the driving element, that is to say the distance separating the center of pivoting of the armature l, and the striker. face of one or other ofthe pallets;
  • r is the effective radius of the driven element, that is to say the distance separating the center of pivoting of the seconds wheel S and the impact-receiving face of each tooth;
  • 9R 1; 9B 7'A in order words when the moments of inertia of the moving element are in the ratio of the square of the respective effective radii of said components.
  • velocities 10' and (a are relatively small and, taking into account the materials which can be used for the elements involved in the impact, it is possible to obtain a transmission coefficient k having a value quite close to l, and this indicates that the impact which takes placed is essentially elastic in nature.
  • the efficiency of the overall timepiece mechanism depends also upon the method by which the electrical energy of the pulses periodically supplied to the transducer R, is converted into mechanical energy to drive the armature.
  • the efficiency of an electrodynamic transducer is proper tional, on the one hand, to the mean velocity of displacement of the armature l and all the moving parts associated therewith, i.e. the drive coil and, on the other hand, and for a given supply voltage, to the mean flux across the coil 10 during the drive phase. It will be understood by those skilled in the art that it is, under these circumstances, to arrange for the means velocity of the armature of the transducer to be very high and for the magnetic field produced by the magnets 11 and 12 to have a particularly high value. It is precisely because it is desirable to enable the armature l to be accelerated very rapidly, that is has been chosen to make the coil 10 mobile and the magnets 11 and 12 fixed.
  • the magnetic flux produced is particularly strong, these magnets being made of a ferromagnetic material having high coercive field strengths.
  • the magnets have a relatively large volume in relation to the volume of the airgap between them, the coil 10 moving through said airgap in the manner described.
  • the moving elements of the transducer are in fact moving, and a disturbing acceleration takes place, the effect of this acceleration will vary depending upon whether it is the direction F or in the opposite direction.
  • the disturbing acceleration will sustain the movement of the armature l which is being driven by the occurrence of a pulse in the coil 10, and this does not constitute any nuisance; in the second case, the acceleration will be opposed to the movement and, if required, may inhibit contact between the pallet 1a and a tooth of the wheel S.
  • the armature l occupies the position shown in FIGS. 1 to 3: As FIG. 3'illust'rates in detail, the pallet lb of the armature is then engaged between two teeth of the wheel 5 and locks the latter against angular movement and accordingly the remainder of the gear system of the timepiece too.
  • the spiral springs 7 and 8 are fully tensioned and exert a returning force on the armature 1 in the direction F so that said armature is swung back towards the left (considered in the drawing) until the pallet lb clears the tooth 11,, the wheel S then experiencing an impact which transfer a new quantity of kinetic energy to it, moving it in the direction F until the pallet lb enters the space defined between said tooth d and the following tooth 11,.
  • the arm 9 which limits the movement, then hits the stop 14.
  • the first impact on the tooth d, of the wheel S simply advances said wheel by a distance corresponding substantially to the length of a tooth pitch, reduced by the width of the pallet la (FIGS. 4 and 5), while the second impact, against the tooth d causes the wheel to advance by a value equivalent to the width of the pallet 1b (FIGS. 6 and 3) so that overall, the wheel S is moved a distance equivalents to a tooth pitch with each electrical pulse received by the electromechanical transducer.
  • FIG. 7 It is a similar situation which is depicted in FIG. 7, the latter illustrating, as a function of time, how the angular velocity (a of the armature l varies each time the electromechanical transducer receives a pulse 1', and how the angular displacement 1 of the wheel S due to the impulse which it periodically receives, takes place.
  • the velocity w rises to a maximum w, as long as the pulse lasts, dropping rapidly to zero at the instant I, at which the impact of the pallet 1a occurs, after which instant the wheel S commences to move, the armature and the wheel then occupying the position shown in FIG. 4.
  • the displacement of the wheel S takes place over an angular interval il up' to the time t that is to say up to the arrival time at which the tooth d, following the one just hit, comes into'contact with the pallet In of the armature 1 (FIG. 5), the latter commencing to move in the direction F under the action of the spiral springs 7 and 8.
  • the number of teeth on the wheel S is of the order of 60 and the frequency of the pulses coming from the circuit ER is of the order of 1 Hz., so that the seconds hand of the timepiece, which is associated with this wheel, indicates the advance in time of I second with each swing of the armature l, i.e. with each pulse.
  • the general arrangement of the armature l, the pallets la and lb, and the toothing of the wheel S, is such that said wheel is never free to move in the angular sense during that part of the swinging movement of the armature which precedes and follows each impulse or impact, the pallets of the armature being alternately in engagement with the toothing.
  • the electromechanical transducer of the timepiece is of the monostable kind so that the driving of the armature l is effected by pulses of the same polarity.
  • this method of driving means that said pulses can be produced in a simple manner, since they can be obtained from the output of a binary sealer for example, it nevertheless gives rise to a mechanical drawback for the following reasons: After the first impact between armature and wheel, the armature loses speed, in fact it may even come to a halt, and is then simply subject to the restoring couple developed by the spiral springs 7 and 8. 0n the other hand, the toothed wheel has received virtually all the momentum energy of the armature so that it is displacing rapidly. The result is that the next tooth of the wheel, i.e. the one following the one just struck by the entry pallet of the armature, may hit said pallet before the latter has been able to clear the circular trajectory described by the tips of the teeth (see FIG. 5).
  • this kind of impact can, under certain circumstances and by virtue of a rebound effect on the part of the wheel S, return the wheel to its initial position so that the timepiece is slow.
  • the electromechanical transducer of the timepiece described remains exactly the same as illustrated in FIGS. land 2 as far as its general structure is concerned, although it will be understood that from the electromechanical point of view it will be modified as compared with the system employed in the case where strictly rectangular waveform pulses are used, as for example the pulses i (FIG. 8).
  • the annature 1 which is virtually at a standstill after the impact, is then not only driven backwards by the spiral springs but also by the effect of the negative polarity pulse 1,.
  • the result is that the armature is accelerated back into the rest position much faster than it would be under the sole effect of the spiral springs 7 and 8, and that as a consequence the pallet la can be withdrawn from the gap between the tooth d, and the tooth a, before the latter hits it, so there is no longer any loss of energy from the wheel S of the kind which would otherwise occur if there was contact between it and the armature 1.
  • the moving elements of the transducer including the spiral springs, the gearing of the timepiece and the differentiating circuit associated with the circuit ER, it is possible to arrange that the sole contacts which take place between the pallets la and lb and the teeth of the wheel S, are ones during which energy is transferred to said wheel by impact with the pallets, said transmission thus being effected with a particularly high efficiency.
  • the drive pulses may take a rectangular form in the manner of the pulses i shown in the diagram V of FIG. 7.
  • a similar effect can equally well be achieved by employing a transducer similar to the one shown in FIGS. 1 and 2, in particular as far as the general form of its elements (notably the pallet la and lb and the teeth of the wheel S) are concerned, and also as far as the method of supply of periodic pulses i is concerned, by dimensioning the moving elements of the transducer and the gearing arrangement in order that the velocity w of the armature after impact is not zero but slightly negative in relation to the velocity u which it has prior to impact.
  • the transducer used in the timepiece described exhibits the following advantages:
  • the positioning of the moving elements of the electromechanical transducer takes places in such fashion that said elements are maintained in a single stable state so that the method by which the transducer is electrically driven becomes particularly simple;
  • the driving of the gear train is in a step-by-step manner at a very low frequency (1 Hz. for example), and this makes it possible to design a mechanical section of the transducer to have dimensions and an accuracy which are, to an order of magnitude, compatible with those of conventional timepieces.
  • An electronic timepiece comprising a device for indicating the time, which device includes a gear train and a time indicator controlled by said gear train, an electronic circuit which produces periodic signals of a predetermined frequency, and an electromechanical transducer for driving said device, which transducer is controlled by the signals produced by the said circuit, wherein said transducer incorporates a member which swings periodically and at the frequency of said signals, between two limiting positions in order, at least once during the course of two successive swings,.to strike successively each tooth of a gear in the gear train, means for limiting to a predetermined value the angular displacement of the gear as a consequence of each impact, said member comprises elements, one of said elements striking the teeth of said gear and following a radial trajectory in relation to said gear at the point of impact, the impact-applying surface of said element and the impact receiving of each tooth of the gear at the time of impact, being contained in a common plane making an angle substantially 45 with a tangent at the center of the zone of impact of the member which strikes against the tooth
  • said pallet of the armature which strikes the toothing of the gear when said device is moving into its unstable limiting position has a second face adjacent the impact applying surface of said element, which second face is substantially perpendicular to the plane of said applying surface.
  • a timepiece as claimed in claim 4, comprising an RC differentiating circuit connected between the electronic circuit and the electromechanical transducer, said differentiating circuit producing a train of two pulses having mutually opposite polarities, in respect of each periodic signal received by the electronic circuit.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electromechanical Clocks (AREA)
US838422A 1968-07-09 1969-07-02 Method of driving the gearing of an electronic timepiece and an electronic timepiece for implementing said method Expired - Lifetime US3604201A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH1022068A CH583929B (fr) 1968-07-09 1968-07-09 Procede d'entrainement du rouage indicateur de l'heure d'une piece d'horlogerie sans balancier et piece d'horlogerie electronique pour la mise en oeuvre de ce procede.

Publications (1)

Publication Number Publication Date
US3604201A true US3604201A (en) 1971-09-14

Family

ID=4360738

Family Applications (1)

Application Number Title Priority Date Filing Date
US838422A Expired - Lifetime US3604201A (en) 1968-07-09 1969-07-02 Method of driving the gearing of an electronic timepiece and an electronic timepiece for implementing said method

Country Status (8)

Country Link
US (1) US3604201A (enrdf_load_stackoverflow)
JP (1) JPS5212583B1 (enrdf_load_stackoverflow)
CH (2) CH1022068A4 (enrdf_load_stackoverflow)
DE (1) DE1935158C3 (enrdf_load_stackoverflow)
FR (1) FR2012586B1 (enrdf_load_stackoverflow)
GB (1) GB1268007A (enrdf_load_stackoverflow)
NL (1) NL6910482A (enrdf_load_stackoverflow)
SU (1) SU536763A3 (enrdf_load_stackoverflow)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3783600A (en) * 1971-07-29 1974-01-08 Junghans Gmbh Geb Electromechanic driving mechanism for the hands of a timepiece
US3805511A (en) * 1972-02-02 1974-04-23 Biviator Sa Electric timepiece assembly
US3844104A (en) * 1972-04-08 1974-10-29 Itt Electromechanical transducer for watches
US3999369A (en) * 1974-04-18 1976-12-28 Valroger Pierre Albert Marie D Electromechanical watch movement
US20140146645A1 (en) * 2012-11-23 2014-05-29 Eta Sa Manufacture Horlogere Suisse Mechanism for driving the hands of an electromechanical watch, provided with a locking device

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT377110B (de) * 1981-10-29 1985-02-11 Mattig Kg Anton Elektromechanisches zaehlwerk
DE3441737A1 (de) * 1984-11-15 1986-05-15 Max-Planck-Institut zur Förderung der Wissenschaften e.V., 3400 Göttingen Verlustarmer direktantrieb fuer kryogene temperaturen

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3488942A (en) * 1967-09-20 1970-01-13 Hamilton Watch Co Pallet type index system

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3488942A (en) * 1967-09-20 1970-01-13 Hamilton Watch Co Pallet type index system

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3783600A (en) * 1971-07-29 1974-01-08 Junghans Gmbh Geb Electromechanic driving mechanism for the hands of a timepiece
US3805511A (en) * 1972-02-02 1974-04-23 Biviator Sa Electric timepiece assembly
US3844104A (en) * 1972-04-08 1974-10-29 Itt Electromechanical transducer for watches
US3999369A (en) * 1974-04-18 1976-12-28 Valroger Pierre Albert Marie D Electromechanical watch movement
US20140146645A1 (en) * 2012-11-23 2014-05-29 Eta Sa Manufacture Horlogere Suisse Mechanism for driving the hands of an electromechanical watch, provided with a locking device
US9188960B2 (en) * 2012-11-23 2015-11-17 Eta Sa Manufacture Horlogere Suisse Mechanism for driving the hands of an electromechanical watch, provided with a locking device

Also Published As

Publication number Publication date
DE1935158B2 (de) 1973-09-13
GB1268007A (en) 1972-03-22
CH1022068A4 (enrdf_load_stackoverflow) 1971-06-15
NL6910482A (enrdf_load_stackoverflow) 1970-01-13
JPS5212583B1 (enrdf_load_stackoverflow) 1977-04-08
FR2012586A1 (enrdf_load_stackoverflow) 1970-03-20
FR2012586B1 (enrdf_load_stackoverflow) 1974-02-22
DE1935158C3 (de) 1978-06-22
DE1935158A1 (de) 1970-01-22
CH583929B (fr) 1977-01-14
SU536763A3 (ru) 1976-11-25

Similar Documents

Publication Publication Date Title
JP5171821B2 (ja) 電気機械式逃がし止め装置とそのような装置を利用する時計部品
EP1914607B1 (en) Timepiece
US3451280A (en) Device for transforming the movement for an electronic watch
JPH0769440B2 (ja) 発電機
US3604201A (en) Method of driving the gearing of an electronic timepiece and an electronic timepiece for implementing said method
US3737746A (en) Quartz crystal controlled stepper motor
GB1232907A (enrdf_load_stackoverflow)
US4050234A (en) Electronic timepiece hand-return mechanism
US5025428A (en) Electromagnetic escapement for mechanically driven watch or clock
US3618311A (en) Synchronized horological system
US3665697A (en) Driving mechanism for electronically controlled timepiece
US3277644A (en) Tuning fork timepiece
US3999369A (en) Electromechanical watch movement
US4266291A (en) Electromagnetic swing device
US4022013A (en) Regulating device for electric timepieces
US3435313A (en) Magnetic timing impulse switch
US3657875A (en) Electro-mechanical drive mechanism for watches and related devices
US3329032A (en) Stepping device for electronic and electrical clocks
US3440813A (en) Electromagnetic vibrator
US3481138A (en) Drive for a balance in an electric timepiece
US4128992A (en) Rocking motor for low cost quartz watch
US3699764A (en) Tuning-fork type electronic clock having push-pull indexing mechanism
US2847818A (en) Electromagnetically operated clocks
US3236043A (en) Magnetic brake for clock escapements
US2757555A (en) Pawl and ratchet mechanism