US3681915A - Balance wheel assembly of a battery-driven timepiece - Google Patents

Balance wheel assembly of a battery-driven timepiece Download PDF

Info

Publication number
US3681915A
US3681915A US76122A US3681915DA US3681915A US 3681915 A US3681915 A US 3681915A US 76122 A US76122 A US 76122A US 3681915D A US3681915D A US 3681915DA US 3681915 A US3681915 A US 3681915A
Authority
US
United States
Prior art keywords
wheel
balance wheel
escape
balance
impulse pin
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
US76122A
Other languages
English (en)
Inventor
Kozaburo Kanazawa
Eiji Kawakami
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.)
Citizen Watch Co Ltd
Original Assignee
Citizen Watch Co Ltd
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 Citizen Watch Co Ltd filed Critical Citizen Watch Co Ltd
Application granted granted Critical
Publication of US3681915A publication Critical patent/US3681915A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • G04C3/04—Electromechanical clocks or watches independent of other time-pieces and in which the movement is maintained by electric means wherein movement is regulated by a balance
    • G04C3/06—Electromechanical clocks or watches independent of other time-pieces and in which the movement is maintained by electric means wherein movement is regulated by a balance using electromagnetic coupling between electric power source and balance
    • G04C3/065—Electromechanical clocks or watches independent of other time-pieces and in which the movement is maintained by electric means wherein movement is regulated by a balance using electromagnetic coupling between electric power source and balance the balance controlling gear-train by means of static switches, e.g. transistor circuits
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00—Machine element or mechanism
    • Y10T74/15—Intermittent grip type mechanical movement
    • Y10T74/1502—Escapement

Definitions

  • This improvement comprises the arrangement of said impulse pin so as to have an offset angle, 20 or more, relative to the common diameter of the balance and escape wheels for compensating unavoidable amplitude reduction as met with consumption of a source battery fitted in the timepiece.
  • the operating amplitude of the balance wheel will naturally be subjected to a corresponding gradual reduction, resulting in a corresponding alteration in the regular stepping movement of the timepiece.
  • a certain brake means is additionally fitted to the mechanism at the cost of an increased power consumption.
  • the hair spring is controlled in its winding angle which results, however, in considerable additional time and cost in the timepiece manufacture.
  • a provision of magnetic brake means is made in close proximity of the balance wheel, so as to perform a similar job for improving the isochronism of the timepiece.
  • TI-Ie main object of the invention is to provide an improved balance wheel, capable of providing a highly stabilized isochronism in the operation of the timepiece fitted therewith, even when the balance wheel is subjected to amplitude variation caused by the battery consumption in the above-mentioned sense.
  • the drive balance wheel according to this invention is so designed and arranged that the impulse pin fixedly mounted on the wheel for driving an escape wheel is positioned so as to establish a central angle of 20 or more on the balance wheel as measured from the common diameter to the said both wheels and with the balance wheel kept at its neutral position.
  • FIG. 1 is an axial sectional view of a preferred embodiment of the drive balance wheel according to the invention wherein, however, the driven escape wheel is also shown.
  • FIG. 2 is an enlarged schematic plan view of a conventional roller of a balance wheel, an impulse pin fixedly mounted thereon and a driven escape wheel, shown in such position of the balance wheel which is held in its stationary or neutral position.
  • FIG. 3 is a similar view to FIG. 2, showing the improved structure according to this invention.
  • FIG. 4 is a rather specific and still further enlarged plan view of a modified shape of a drive balance wheel embodying the principles of the invention, wherein the driven escape wheel, sensing and driving permanent magnets mounted on the balance wheel and a stationary coil assembly adapted for cooperation with these permanent magnets are shown additionally.
  • FIGS. 5 and 6 are isochronic performance curves of a drive balance wheel according to this invention.
  • FIG. 1 of the accompanying drawings numeral 10 denotes a balance wheel arbor which is rotatably mounted with its both ends by conventional timepiece plate 20 and a conventional balance bridge 21 which are shown only partially on account of their very popularity and for simplicity of the drawing.
  • a pair of balance wheel discs 11a and 11b are fixedly attached at their centers to the arbor 10 and carry thereon a plurality of permanent magnets 12a and 12b and counter weights 13a and 13b, said magnets being arranged to electromagnetically cooperate with a stationary coil means 14 which is fixedly mounted on the plate 20 through a mounting means 15.
  • the coil means 14 consists of a sensing coil element and a drive coil element which are compoundly wound into a single coil mass.
  • coil means 14 and mounting means 15 are shown in chain dotted lines and substantially by their respective outlines only for simplicity.
  • the said coil elements are connected electrically with a conventional electronic drive circuit, not shown, and a battery, again not shown, for transmitting sensed electric signals to and receiving drive currents from the electronic circuits when the balance wheel is kept in its oscillatory movement, as will bemore fully described hereinafter.
  • the balance wheel is provided with a conventional hair spring 16 with its ends fixedly attached to conventional stud 17 and collet 18.
  • An escape wheel 23 having peripheral ratchet teeth 23a is rotatably mounted by its arbor 25 between a second bridge 24, only partially shown, and the plate 20, said teeth being positioned in the acting area of the impulse pin 22 when the escape wheel 23 rotates.
  • the escape arbor 25 is formed with an escape pinion 26 which is operatively connected with a conventional movement gear train, for driving the latter, although not shown.
  • a positioner magnet 27 for the escape teeth 23a is mounted fixedly on the plate 20.
  • the centers of the balance wheel and thus the balance wheel arbor l0 and the escape shaft 25 are denoted in FIGS. 2 and 3 at O and 0 respectively; the common diameter connecting these centers is shown by a chain-dotted line 28, respectively.
  • the impulse pin 22 When the balance wheel is kept stationary and in its neutral position illustrated by way of example in FIGS. 2 and 3 for the case of the conventional and the inventive arrangement, respectively, the impulse pin 22 will occupy the position on the common diameter in the conventional case and at certain angularly offset position relative to the latter. According to our practical experiments, this offset angle alpha should be 20 or larger.
  • the electronic timepiece of the above kind employing the escape wheel the balance wheel amplitude will be subjected to a gradual reduction with reduction of the battery voltage, and this kind of amplitude reduction will naturally and adversely affect upon the isochronic performance of the timepiece.
  • the thus caused isochronic error depends upon various factors such as escape error, winding angle of hair spring, eccentric mounting of the latter, shift of the center of gravity, and the like.
  • the escape error which constitutes a main error of these various errors is so advantageously controlled that all the remaining errors may substantially be cancelled out.
  • the escape error will increase gradually for a certain constant amplitude of the balance wheel oscillation, and the thus resulted error is, as ascertained by our practical experiments, intimately related with increase of the offset angle of the impulse pin.
  • any person skilled in the art may well recognize that there is an exponential relationship between the balance wheel amplitude reduction in the above sense and the isochronic characteristic curve of the timepiece.
  • the escape error caused to appear in a latent sense in the arrangement according to this invention by the offset arrangement of the impulse pin takes always in the shape of an exponential curve of substantially similar nature as before, yet in the opposite or compensating sense.
  • This latent error can be negative or positive, as the case may be, relative to the common diameter to the both balance and escape wheels.
  • the impulse pin is positively offset from the the common diameter to that which has been shown and described hereinabove.
  • a certain offset angle and its positive or negative sign for the impulse pin can also be determined upon performing several minor experiments, so as to substantially cancel out the overall error.
  • FIGS. 5 and 6 represent isochronic error curves for the impulse pin mounted at nil and 20 of the offset angle as hinted in FIGS. 2 and 3, respectively, as being caused by the battery voltage variation.
  • the escape error would be substantially nil by the provision of the impulse pin on the common diameter.
  • the isochronic curves shown in FIGS. 5 and 6 represent each an appreciable inclination of change with gradual reduction of the source voltage, representing in the mean (see K) a daily stepping error of figure, 0' represents again a standard deviation.
  • the escape arrangement shown in FIG. 2 has a negative isochronic characteristic curve as ascertained by practical experiments, it is necessary to a positive escape error for cancelling out the said negative error. Therefore, by positioning the impulse pin 22 so as to have a clockwise offset angle relative to the common diameter 28, the pin 22 will turn in the direction shown by the small arrow and apply an impulse force onto one of the escape teeth 23a of the escape wheel at a position beyond the newly established neutral position 29 of the balance wheel during the forward oscillation stroke of the latter. During the reverse stroke of the impulse pin 22, it will apply an impulse force onto one of the escape teeth 23a at a position in advance of the neutral position.
  • the escape wheel 23 will perform a certain return movement, not only in the forward oscillation stroke of the balance wheel shown by the small solid arrow, but also in the reverse oscillation stroke of the same wheel in the direction opposite to that, as shown by the dotted arrow.
  • the escape wheel 23 will be returned to the original position upon performing said slight reverse movement.
  • the drive force exerted by the impulse pin 22 onto the escape teeth 23a in the forward direction shown by the arrow is selected to be larger than that applied by the pin in the reverse direction.
  • the applying force by the pin is larger than that which will be applied after passage of the pin through the neutral position 29. This will result in the development of a positive escape error which can effectively compensate the aforementioned negative isochronic characteristic.
  • the initial rotational direction and the offset angle (alpha) of the impulse pin 22 is determined based upon the isochronic characteristic as determined for the offset angle selected to nil. In practice, however, it will suffice to set the compensation for the case of the minimum usable source voltage such as, for instance, 1. 1 volts in the case of FIGS. 5 and 6.
  • FIG. 4 illustrates a modification from that shown and described hereinabove wherein modified balance wheels proper 11a (11b) are fixedly attached to a balance arbor 10' and carry thereon permanent magnets 12a' (12b') and 12c (12d) adapted to electromagnetically cooperate with coil assembly 14.
  • a unified and arcuated counter weight mass 13 is fixedly mounted on the balance wheel.
  • an impulse pin 22' fixedly attached thereto as before.
  • This impulse pin 22 is also positioned with an offset angle amounting to 20 or more, relative to the common diameter of the balance wheel and the escape wheel.
  • Numeral 23' denotes the conventional escape wheel of conventional design and having its arbor rotatably mounted as before, although not specifically shown, between the second bridge and the timepiece plate as at 24 and 20 in the foregoing embodiment.
  • the balance wheel With the balance wheel kept in its stationary or neutral position, in the case of the timepiece according to this invention, the impulse pin is kept in no physical contact with the escape tooth, the balance wheel can be started at the beginning stage of the balance wheel oscillation practically under no load, thus providing a smooth and effective starting characteristic being attained without use of any mechanical starter means and capable of providing a favorable and ment of the oscillation amplitude.
  • a drive balance wheel assembly for use in an electronic timepiece having an impulse pin fixedly mounted on the balance wheel arbor for driving cooperation with an escape wheel, and a mounting plate for rotatably supporting said balance wheel arbor and escape wheel
  • said escape wheel having a plurality of ratchet teeth equally spaced around the outer periphery thereof, said ratchet teeth having two parallel radial edges, the outermost edge of each radial tooth forming an acute angle with the edge of said tooth on the side in the direction of rotation of said escape wheel
  • said impulse wheel being formed as a rectangular pillar mounted perpendicularly on said balance wheel for engagement with said ratchet teeth in both directions of rotation of said balance wheel arbor, said impulse pin being positioned so as to establish a central angle of 20 or more on the balance wheel as measured ahead of the common diameter to said both wheels with the balance wheel kept at its neutral position, and a permanent magnet mounted on said plate between said plate and the ratchet teeth of said escape wheel for cooperation with the planar surface of each ratchet tooth

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Electromagnetism (AREA)
  • Power Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Electromechanical Clocks (AREA)
  • Transmission And Conversion Of Sensor Element Output (AREA)
US76122A 1969-09-29 1970-09-28 Balance wheel assembly of a battery-driven timepiece Expired - Lifetime US3681915A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP44077676A JPS4840111B1 (enrdf_load_stackoverflow) 1969-09-29 1969-09-29

Publications (1)

Publication Number Publication Date
US3681915A true US3681915A (en) 1972-08-08

Family

ID=13640471

Family Applications (1)

Application Number Title Priority Date Filing Date
US76122A Expired - Lifetime US3681915A (en) 1969-09-29 1970-09-28 Balance wheel assembly of a battery-driven timepiece

Country Status (4)

Country Link
US (1) US3681915A (enrdf_load_stackoverflow)
JP (1) JPS4840111B1 (enrdf_load_stackoverflow)
DE (1) DE2047392A1 (enrdf_load_stackoverflow)
GB (1) GB1331271A (enrdf_load_stackoverflow)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3949547A (en) * 1973-10-31 1976-04-13 Ebauches S.A. Escapement or counting mechanism for a timepiece having a balance-wheel
US4002021A (en) * 1974-11-02 1977-01-11 Les Fabriques D'assortiments Reunies Rotary escapement for timepiece
US4122663A (en) * 1976-03-18 1978-10-31 Kock Bruce A Stop watch and timing device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6059230A (ja) * 1983-09-12 1985-04-05 Takiron Co Ltd 集水管の埋設施工方法

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3949547A (en) * 1973-10-31 1976-04-13 Ebauches S.A. Escapement or counting mechanism for a timepiece having a balance-wheel
US4002021A (en) * 1974-11-02 1977-01-11 Les Fabriques D'assortiments Reunies Rotary escapement for timepiece
US4122663A (en) * 1976-03-18 1978-10-31 Kock Bruce A Stop watch and timing device

Also Published As

Publication number Publication date
GB1331271A (en) 1973-09-26
JPS4840111B1 (enrdf_load_stackoverflow) 1973-11-28
DE2047392A1 (de) 1971-04-01

Similar Documents

Publication Publication Date Title
JP4722445B2 (ja) 電子調整器と連結した機械式ムーブメントを有する時計
JP4630621B2 (ja) 電子調整器と連結した機械式ムーブメントを有する時計
US3681915A (en) Balance wheel assembly of a battery-driven timepiece
GB1598636A (en) Electronic watch movement
US3469389A (en) Electromechanical vibrator assembly for a timepiece
US4744066A (en) Quartz analog movement with lavet stepping motor and large energy cell
US3901018A (en) Timepiece
US3472020A (en) Electrically powered timepiece
US3708974A (en) Pallet attracting construction
US3780521A (en) Electronic timepiece
US3635011A (en) Elapsed-time indicator
US4461580A (en) Watch, the back cover of which constitutes a plate
US3670493A (en) Indexing mechanism for electric/electronic timepieces
US3603076A (en) Timepiece comprising an optical means for indicating the beat of the seconds
US3312053A (en) Step by step drvie mechanism for timepiece
JPS6356509B2 (enrdf_load_stackoverflow)
CA1071879A (en) Rocking motor for low cost quartz
US3808792A (en) Drive mechanism of an electric timepiece
US3740942A (en) Low amplitude indexing mechanism for horological instruments
JPS6052393B2 (ja) 腕時計の輪列構造
US3075345A (en) Electrically-powered time devices
JP4581443B2 (ja) 暦表示機能付電子時計
US3802179A (en) Electronic timepiece
US3224183A (en) Electrically actuated time integrating device
US3236043A (en) Magnetic brake for clock escapements