US3745758A - Electric and electronic timepiece - Google Patents

Abstract

An electric or electronic timepiece having at least one transistor the base of which is polarized by a source of current, and switch means in the control circuit for said transistor, whereby the ''''rest current'''' from said source of current when said switch means is open is low when compared with the current consumed when said switch means is closed.

Description

United States Patent [1 1 Kuritz [451 July17, 1973 ELECTRIC AND ELECTRONIC TIMEPIECE [75] Inventor: Masahiro Kuritz, Nagano, Japan [73] Assignee: Kabushiki Kaisha Suwa Seikosha,

Tokyo, Japan [22] Filed: Aug. 25, 1971 [21] Appl. No.: 174,601

Related U.S. Application Data [63] Continuation-impart of Ser. No. 888,773, Dec. 29,

1969, abandoned.

[52] U.S. Cl 58/23 A, 58/28 A, 58/85.5 [51] Int. Cl. G04c 3/04, G04b 27/00 [58] Field of Search 58/23 R, 23 A, 23 AC,

58/28 R, 28 A, 28 B, 88.5

[56] References Cited UNITED STATES PATENTS 3,526,088 9/1970 Meitinger 58/85.5

3,200,578 8/1965 Besson 58/23 A FOREIGN PATENTS OR APPLICATIONS 1,209,961 2/1963 Germany 58/23 A Primary Examiner-Richard B. Wilkinson Assistant Examiner-Edith C. Simmons .lackmon Attorney-Alex Friedman et al.

[5 7 ABSTRACT An electric or electronic timepiece having at least one transistor the base of which is polarized by a source of current, and switch means in the control circuit for said transistor, whereby the rest current" from said source of current when said switch means is open is low when compared with the current consumed when said switch means is closed.

5 Claims, 5 Drawing Figures PATENIELJIH 1 7 m5 SHLU 2 [If 2 ELECTRIC AND ELECTRONIC TIMEPIECE This is a continuation-in-part application of now abandoned application Ser. No. 888,773 filed Dec. 29, 1969 and now abandoned.

BACKGROUND OF THE INVENTION The present invention relates to an electric timepiece of the type having an electronic circuit, including at least one transistor, the base of which is polarized by a source of current. In such electric or electronic timepieces, the timing mechanism is electronically driven, and in order to minimize the drain on the source of current when the timepiece is stored, it is necessary to avoid current flow by maintaining polarization of the base of the transistor during such storage. For this purpose, provision has been made for disconnecting the source of current, generally by means of a switch. However, in such an arrangement, if a fault occurs in the operation of the disconnection switch, its position in the circuit causes the following disadvantages. The electric contact resistance is increased and an electric energy loss occurs in a contact point of the switch. The electric energy for driving the timepiece mechanism is therefore decreased. This condition could cause a failure of the isochronism of the timepiece of eventually, the stopping of the timepiece. These defects are avoided by the arrangement according to the invention.

SUMMARY OF THE INVENTION Generally speaking, in accordance with the invention, a control circuit for an electric or electronic time piece is provided-including at least one transistor, a source of current connected to said transistor so that the base thereof is polarized, a driving circuit connected to said transistor, a control circuit connected to said transistor for control of the operation thereof, and switch means connected in series with said control circuit for reducing the current from said source of current by means of cutting off the base current of said transistor when said switch means is open, as compared with the current from said source of current when said switch means is closed.

Accordingly, it is an object of this invention to provide means for avoiding the flow of an excessive current when the electronic control circuit of the timepiece is inoperative, as during the time when the timepiece is stopped during storage, irregardless of the contact resistance of the components of said watch.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a partial plan view of one embodiment of the movement of the electronic timepiece according to the present invention;

FIG. 2 is a circuit diagram of the timepiece of FIG.

FIG, 3 is a plan view of another embodiment of the movement of the electronic timepiece according to the present invention;

FIG. 4 is an electric circuit diagram of the timepiece of FIG. 3; and

FIG. 5 is a fragmentary enlarged sectional view taken through the winding stem and clutch wheel of the electronic timepiece of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIGS. 1 and 2, the timepiece illustrated includes an electric cell which is not visible in FIG. 1, but is represented diagrammatically at l in FIG. 2. Through the first driving coil 2 and the second driving coil 3, this cell feeds the electromagnetic energy to an anchor magnet (not shown) to maintain oscillation of the balance member 4. The electronic circuit is carried entirely by insulating plates 5 and 6. The insulating plate 5, in the form of an annular segment, carries thereon a controlling transistor 7, a driving transistor 8, resistors 9, l0, and 11, and a condenser 12. On the other hand, the insulating plate 6 in the form of a ring (shown segmentally in FIG. I) carries said insulating plate 5, the first driving coil 2, the second driving coil 3, a detecting coil 13 and a diode 14.

This electronic circuit also includes a switch 15 connected between a turning point for the control circuit (that is, a junction between the first driving coil 2 and the second driving coil 3) and the resistance 9 which is connected to the emitter of the control transistor 7. Switch 15, which serves to open the base circuit of driving transistor 8, is operated by a switch operating portion 16a of a balance regulating lever 16. The balance regulating lever 16 has a projection 16b engaging in a groove 17a of a clutch wheel 17 provided with a handsetting pinion in its end. Clutch wheel 17 is mounted for slideable displacement on a portion of shafi 24 of winding stem 18. The structure for displacing clutch wheel 17 along shaft 24 in response to the displacement of winding stem 18 is not shown in FIG. 1, but is shown in FIGS. 3 and 5. Specifically, clutch wheel 17 is mounted on a faceted portion 30 (FIG. 5) of winding stem shaft 24, which permits the clutch wheel to be longitudinally displaced along the shaft while being rotated in response to the rotation of the winding stern. Setting lever 25 is mounted for pivotable rotation about lever pin 27. A pin 26 is mounted on setting lever 25 and rides in annular groove 28 in shaft 24. When the winding stem, and therefore shaft 24 is pulled outwardly, setting lever 26 is pivoted in the clockwise direction so that engaging portion 25a of said setting lever engages against one arm of clutch lever 23. Said clutch lever is pivotable about the axis defined by screw 29 and is engaged in annular groove 17a of clutch wheel 17.

When the hands are set, a pull is exerted on the winding stem 18 and this causes setting lever 25 to rotate clockwise about setting lever pin 27, which in turn causes clutch lever 23 to rotate counter clockwise about screw 29, which in turn longitudinally displaces clutch wheel 17 in the downwardly direction as viewed in FIGS. I. and 3. Referring to FIGS. 1 and 5, the balance regulating lever 16, the projection 16b of which also engages in groove 17a of the clutch wheel 17, turns counterclockwise about its pivot 16c. Then the switch 15 is operated by the switch operating portion 16a of the balance regulating lever 16 to disconnect the contact point a. In this way the emitter circuit of the controlling transistor is open and the operation of said transistor is stopped and thus the whole circuit is broken. At the same time, the side surface of a balance member 4 is pushed by the end portion 16d of a balance regulating lever so as to lock a balance member 4.

When the watch is to be stored, the stem 18 is brought into the hand-setting position so as to stop the movement. In this rest or inoperative position, the current supplied by the cell 1 is very low, between 0.05 and 0.3 micro-ampere. It is less than 3 per cent of the current consumed when the switch 15 is closed and the watch is normally running. Thus the energy used after storage for 1 year, for example, will be less than 3 milliampere-hours.

The main advantage of the invention resides in the fact that by providing the control circuit portion with the switch 15, if the electric contact of the switch is inoperative and the contact resistance is increased by a small amount (1 or 2 K ohms), the terminal voltages of the first driving coil 2 and the second driving coil 3 are not decreased and further the control circuit would continue to operate correctly. As a result, the performance of the timepiece is not impaired. Also, if a switch is open, rest current is very low.

The arrangement according to the invention could also apply to the case where the electronic circuit does not serve to control the regulating or balance member of the timepiece directly but serves, for example, to wind a mainspring intermittently. In such a case it would be advantageous to open the contact point of the switch between each winding operation, in order to avoid unnecessary wastage of the cell. In some timepieces, provision could be made for automatically controlling a switch by the winding member of a mainspring. Moreover, the invention could also apply to timepieces such as quartz crystal watches when they are stored with only the oscillation circuit operated,

and the frequency dividing circuit not operated, so that 7 only the regulating means normally operates, avoiding aging of the quartz crystal.

Referring now to FIGS. 3 and 4, a second embodiment of the electronic watch according to the invention is depicted. In said electronic watch, circuit block 21 is provided with a switch pin 22 to define the contact point of the switch according to the invention. Said switch pin is mechanically connected with clutch lever 23 to complete the electrical circuit. In this embodiment, when stem shaft 24 is pulled out, setting lever 25 is rotated clockwise as described above, and the position of clutch lever 23 is moved to the position shown in dashed lines at reference numberal 23', at which point said clutch lever is disengaged from switch pin 22, and the electric circuit is cut off. In this embodiment, balance regulating lever 16 of FIG.'1 serves no part in the operation of switch 15 and may be dispensed with.

Referring now to the corresponding electric circuit of FIG. 4, driving coil 31 and detecting coil 32 are magnetically engaged with a vibrator such as a balance wheel or tuning fork (not shown). Transistor 38 is provided with a base bias resistor 34 and a coupling condenser 33. The circuit constant of the oscillation circuit for maintaining the oscillation of the vibrator is determined byvadjusting the value of resistor 34 and condenser 33. Reference numeral 35 refers to a switch pin corresponding to switch pin 22 in the embodiment of FIG. 3, while switch member 36 corresponds to the clutch lever 23 in the embodiment of FIG. 3.

When the switch is disposed in the position d. c. in FIG. 4, when the stem is pulled out, the switch is in the open position and an extremely small current flows from battery 37, minimizing the drain thereon. It is advantageous to connect the positive side of the battery to the plate of the watch, so that a mechanical part such as the setting lever or clutch lever can be used as the contact point without necessitating insulation of the mechanical elements. In the circuit of FIG. 4, switch 35, 36 could also be positioned at any point in the d.c. path between the node defined by the battery 37 and drive coil 31 and the base of transistor 38, to open the base circuit of transistor 38.

It will thus be seen that the objects set forth above, and those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above constructions without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What is claimed is:

1. An electronic circuit for an electric or electronic timepiece comprising at least one transistor having an emitter, collector and base; a source of current connected to said transistor so that said base is polarized;

a driving circuit connected to said transistor; a control circuit connected to said transistor base for control of the operation thereof; and switch means connected in series with said control circuit and transistor base for reducing the current from said source of current by means of cutting off the base current of said transistor when said switch means is open, as compared with the current from said source of current when said switch means is closed.

2. An electronic circuit as recited in claim 1, including a driving coil having first and second portions connected in series by a junction terminal, said driving coil being connected in series with the emitter-collector path of said first-mentioned transistor and said source of current, said control circuit including a further transistor having a base, collector and emitter, said further transistor being connected for the control of said first transistor, a detecting coil, and a charging circuit means connected in series with said detecting coil between the base of said further transistor and the junction between said driving coil and said collectoremitter path of said first-mentioned transistor, said switch means being connected in series with the emitter-collector path of said further transistor and the junction terminal between said portions of said driving coil.

3. An electronic circuit as recited in claim I, including a driving coil connected in series with the emittercollector path of said first-mentioned transistor and said source of current; said control circuit including a detecting coil; a coupling condenser connected in seties with said detecting coil between said transistor base and the junction between said driving coil and said said movable switch member for selectively opening and closing said switch means in response to the dis placement of said winding stem.

5. An electronic circuit as recited in claim 4, wherein said timepiece includes a plate for supporting said movable contact member, said source of current including a battery having a positive terminal electrically connected to said plate.

Claims (5)

1. An electronic circuit for an electric or electronic timepiece comprising at least one transistor having an emitter, collector and base; a source of current connected to said transistor so that said base is polarized; a driving circuit connected to said transistor; a control circuit connected to said transistor base for control of the operation thereof; and switch means connected in series with said control circuit and transistor base for reducing the current from said source of current by means of cutting off the base current of said transistor when said switch means is open, as compared with the current from said source of current when said switch means is closed.

2. An electronic circuit as recited in claim 1, including a driving coil having first and second portions connected in series by a junction terminal, said driving coil being connected in series with the emitter-collector path of said first-mentioned transistor and said source of current, said control circuit including a further transistor having a base, collector and emitter, said further transistor being connected for the control of said first transistor, a detecting coil, and a charging circuit means connected in series with said detecting coil between the base of said further transistor and the junction between said driving coil and said collector-emitter path of said first-mentioned transistor, said switch means being connected in series with the emitter-collector path of said further transistor and the junction terminal between said portions of said driving coil.

3. An electronic circuit as recited in claim 1, including a driving coil connected in series with the emitter-collector path of said first-mentioned transistor and said source of current; said control circuit including a detecting coil; a coupling condenser connected in series with said detecting coil between said transistor base and the junction between said driving coil and said source of current, and a base bias resistor connected between said junction and said transistor base, said switch means being connected between said junction and said transistor base in series with said base bias resistor.

4. An electronic circuit as recited in claim 1, wherein said switch means includes a fixed and a movable contact, said timepiece including a winding stem, and means for operatively connecting said winding stem to said movable switch member for selectively opening and closing said switch means in response to the displacement of said winding stem.

5. An electronic circuit as recited in claim 4, wherein said timepiece includes a plate for supporting said movable contact member, said source of current including a battery having a positive terminal electrically connected to said plate.

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