Small-Sized Quartz Crystal Wristwatch

This invention is directed to a small-sized quartz crystal electronic wristwatch, and in particular to providing each of the operative components of an electronic wristwatch on a support plate particularly configured to affect miniaturization of the wristwatch.

In recent years, because of the accuracy that was not heretofore obtainable in mechanical watches, electronic wristwatches, and in particular electronic wristwatches having a quartz crystal vibrator as a time standard, have become increasingly more popular. One disadvantage that has been noted however, with respect to such electronic wristwatches, is their relative bulkiness, when compared with mechanical wristwatches.

This disadvantage is particularly noted in women's fashion, which places a premium on small-size movements in order to permit the wristwatch to be styled to meet fashion requirements. Accordingly, a highly miniaturized and thinner electronic wristwatch movement that is sufficiently miniaturized to be utilized in watches designed particularly for women is desired.

Generally speaking, in accordance with the instant invention, a miniaturized quartz crystal vibrator wristwatch is provided. The wristwatch includes a support plate having a battery disposed thereon. A quartz crystal oscillator circuit is disposed on the support plate and is coupled to the battery for producing a high frequency time standard signal. Divider circuitry is disposed on the support plate and coupled to the oscillator circuit for dividing high frequency time standard signal produced by the oscillator circuitry and for producing a low frequency timekeeping signal. An electro-mechanical transducer is disposed on the support plate to receive the low frequency timekeeping signal and in response thereto be continuously incrementally rotated. A center wheel is rotatably disposed on the support plate and a gear train is disposed intermediate the electro-mechanical transducer and the center wheel for transmitting to the center wheel a predetermined amount of rotation in response to each incremental rotation of said electro-mechanical transducer. The support plate is constructed and arranged to position the battery so that the periphery thereof is disposed proximate to the center wheel, so that the battery is disposed in overlapping relationship with the center wheel, in plan view, and is further constructed and arranged to position the gear train out of overlapping relationship with the battery in plan view.

Accordingly, it is an object of this invention to provide a quartz crystal vibrator electronic wristwatch construction that is substantially reduced in size.

A further object of this invention is to provide an improved support plate for supporting each of the operative components of a quartz crystal electronic wristwatch and thereby define a wristwatch movement that is reduced in size.

Still a further object of the instant invention is to provide a quartz electronic wristwatch construction wherein the operative components of the wristwatch and the support plate are configured to effect a substantial miniaturization of the electronic wristwatch movement.

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.

For a fuller understanding of the invention, reference is had to the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a plan view of a quartz crystal electronic wristwatch constructed in accordance with a preferred embodiment of the instant invention;

FIG. 2a is an elevational sectional view taken through the electronic wristwatch depicted in FIG. 1;

FIG. 2b is a further sectional view taken through the electronic wristwatch depicted in FIG. 1;

FIG. 3 is a plan view of the regulating mechanism of the electronic wristwatch depicted in FIG. 1;

FIG. 4 is an elevational sectional view of a portion of the electronic wristwatch depicted in FIG. 1; and

FIG. 5 is a plan view of the electronic timepiece depicted in FIG. 1 illustrating the relationship between the wheels of the front gear train and back gear train.

As is detailed below, the instant invention is directed to providing an electronic wristwatch construction that is smaller in size and thinner than that heretofore obtainable by optimizing the space provided in the case of an electronic wristwatch. To this end, each of the respective operative components comprising the electronic timepiece movement have been configured to obtain a smaller sized electronic wristwatch, taking into account the battery, step motor coil and quartz crystal vibrator assembly, which elements are the largest operative elements of the electronic wristwatch and, hence, are determinative in effecting a reduction in the size thereof. As is demonstrated below, the electro-mechanical transducer, gear train, circuitry, tuner capacitors, etc., have been constructed and arranged with respect to the battery, step motor coil and quartz crystal vibrator assembly to provide a highly reliable miniaturized electronic wristwatch.

Reference is initially made to FIGS. 1, 2a and 2b, wherein an electronic wristwatch, constructed in accordance with the instant invention, is depicted. A support plate 1 is adapted to support a DC battery 2, which battery is positioned so that the periphery thereof extends to the position 2a at the periphery of the support plate, and additionally, extends to a position 2b that is proximate to the center of the support plate 1. It is noted that the smallest DC battery comercially available at this time is 7.9 mm in diameter. Moreover, if the quartz crystal wristwatch is provided with three hands (hours, minutes, seconds), the pinion of the second hand shaft, or alternatively, the gear and battery cannot be disposed in overlapping relationship when seen in plan view. In such event, the minimum permissible diameter of movement is the sum total of the diameter of the battery, the diameter of the gear or pinion, and the remaining members and spaces therebetween. Accordingly, in small-sized electronic wristwatches, constructed in accordance with the prior art, the minimum diameter has been about 18 mm. The instant invention is directed to an electronic timepiece having only two hands (hours, minutes), and a suitable gear train for driving same, in order to effect suitable miniaturization of the electronic timepiece.

Returning to FIG. 1, the DC battery 2 is disposed in overlapping relationship, as seen in plan view, with center wheel 25b and pinion 25 (FIG. 2a) supporting same. Such overlap permits the electronic movement of a wristwatch, constructed in accordance with the instant invention, to have a maximum diameter of 16 mm and a minimum diameter of 13.6 mm. Also, as illustrated in FIG. 1, the support plate is constructed and arranged to dispose the gear train on the opposite side of an imaginary (dashed) line A--A, which line diametrically intersects the center wheel 25b. A further imaginary line B--B is substantially in alignment with the lengthwise extent of stem 31.

To obtain this miniaturization, a coil 3 and the quartz crystal vibrator assembly 4 are positioned on the support plate 1 in non-overlapping relationship, as seen in plan view, with respect to each other and with respect to the battery 2. It is noted that the quartz crystal vibrator is preferably formed by photo-eteching since such a manufacturing technique contributes to mass production of an electronic wristwatch constructed in accordance with the instant invention. Moreover, the quartz crystal vibrator is disposed in a cylindrical case in order to reduce the space occupied by the quartz crystal vibrator assembly in the electronic wristwatch, and thereby further reduce the size of the movement. The quartz crystal vibrator assembly 4 is disposed in a circuit block 5, which block includes, in addition to the quartz crystal vibrator assembly, a C-MOS IC 6 for producing the current consumption of the electronic timepiece circuitry and a trimmer capacitor 7 for tuning the high frequency time standard signal produced by the quartz crystal vibrator assembly. It is noted that the C-MOS IC 6 is disposed in overlapping relationship with the vibrator assembly 4, as seen in plan view, in order to reduce the space occupied thereby.

The circuit block 5 provides the entire circuitry for an electronic timepiece including the remaining circuitry for defining the oscillator circuitry to which is coupled the quartz crystal vibrator assembly for the purpose of producing a high frequency time standard signal, as well as the divider circuitry for dividing down the high frequency time standard signal and producing a low frequency timekeeping signal to be applied to the coil of the electro-mechanical step motor to effect a stepping of the rotor through a predetermined incremental rotation. As is detailed below, assembly, adjustment of the time displayed by the electronic timepiece, and post-sales service are facilitated by the manner in which the support plate positions the respective operative elements and, additionally, the gear train including the third wheel bridge 8, illustrated in FIG. 2a.

As is illustrated in FIGS. 1 and 5, unlike conventional electronic wristwatches, the support plate 1 is not circular. Instead, a side-cut form is utilized so that the cutaway portions from the usual circular shape are equally shaped arcs that intersect the circular portion of the plate remaining. By referencing the stem 31 at the three 0'clock position, it becomes apparent that the dimension of the timepiece in the three 0'clock-nine o'clock direction is considerably reduced with respect to the dimension of the electronic timepiece in the twelve O'clock-six o'clock direction. Thus, each of the edges of the support plate, defining the periphery, are arcuate in shape, with the opposed arcuate edges having equal radii. Although it would appear that a conventional circular plate would provide more space for the operative components of the electronic timepiece, it has been found that the additional area, provided by a circular support plate, is utilized as a contact surface such as 1a for mounting the casing, and accordingly, the non-circular support plate of the instant invention eliminates this unnecessary surplus space. Moreover, the non-circular side-cut support plate 1 is substantially square in appearance which permits the case of the watch to take on a substantially square configuration, which configuration is particularly popular in women's fashion. Also, conventional oval-shaped support plates are clearly larger than the side-cut support plate 1 of the instant invention.

Referring now to FIGS. 2a and 2b, the side-cut support plate 1 is further formed to facilitate the manner in which the operative elements of the timepiece are positioned thereby, and additionally, to facilitate obtaining access to the respective operative elements. The quartz crystal vibrator assembly 4 is secured to the rear surface of the circuit block 5 and is positioned under the surface of the plate supporting the circuit configuration. In order to securely position the quartz crystal vibrator assembly 4 on the rear side of the circuit block 5, and additionally positionally secure same with respect to the support plate 1, the support plate 1 is provided with a recess 1b defined by inclined side walls 1d, which walls define the recess in which the quartz crystal vibrator assembly is secured. Additionally, a through hole is provided on the front surface of the support plate 1 in order to facilitate the removal of the quartz crystal vibrator from the recess 1b formed in the support plate 1 for receiving the quartz crystal vibrator assembly 4. It is noted that the quartz crystal vibrator assembly is disposed near the periphery of the support plate 1 in order to assure that same will be disposed out of overlapping relationship, when seen in plan view, from the battery 2 and coil 3. The forming of a recess, having inclined walls in the support plate, instead of reducing the thickness of the support plate throughout prevents the support plate from being damaged during assembly and reduces the fragility of same that would likely be caused if the support plate were reduced in thickness throughout the entire periphery thereof. Similarly, as is illustrated in FIG. 2b, inclined surfaces are provided in the support plate 1 in order to receive the battery 2 so that the strength of the support plate is also not diminished by reducing same throughout to a thickness sufficient to accommodate the battery 2.

The battery 2 is disposed in a recess formed in the support plate and is coupled to the circuitry of the electronic timepiece through a positive lead plate 9 and a negative lead plate 12. Positive lead plate 9 is secured to the support plate 1 by fixing pins 10 and 34 (FIG. 4) to thereby dispose the positive lead plate in electrical connection with the circuit elements through the fixing pin 10. The negative battery lead plate 12 is fixedly secured to the circuit block in order to couple the negative terminal of the battery thereto. An insulating plate 11 for insulating the lead plate 12 and lower terminal of the battery from the support plate is disposed in the battery receiving recess in the support plate 1 and is provided with a notch 11a that is configured to insure that same is out of vertical contact with the center wheel and cannon-pinion 25 supporting the center wheel. Resilient lead 13 defines an output terminal of the C-MOS-IC circuit 6 and is resiliently disposed against the electrode portion 16 of coil core 14 for generating a magnetic flux in the coil 3. Specifically, as is illustrated in FIG. 1, the resilient output lead 13 is biased against the electrode portion 16a of the coil lead plate 16 to which both ends of the coil wire 15 are soldered. By this configuration, the output signal of the circuitry is transmitted to the coil 3. Coil lead plate 16 is mounted to the surface of the coil core 14 with a portion thereof protruding beyond the coil core 14. Although the electrodes can be formed in the shape of the coil lead plate in conventional electronic wristwatches, as the movement of the electronic wristwatch is miniaturized, the coil core 14 is reduced in shape and area, thereby reducing the area of the coil lead plate 16, and thereby requiring a like reduction in the area of the electrode 16a. The external shape of the electrode 16a of coil lead plate 16 is therefore configured to eliminate this problem. However, the electrode can be bent to the side of the coil lead plate 16 as a result of a pressure applied by resilient output lead 13 and thereby cause output lead 13 to contact coil core 14 and define a short circuit therebetween. Accordingly, the coil lead plate 16 is shaped to protrude beyond that of the coil 14 in order to prevent the electrode from bending and otherwise causing a short circuit between the output lead and the coil core 14.

The coil core 14 includes a portion disposed proximate to the periphery of the battery 2 in order to aid in guiding the battery into position, and thereafter for positioning the battery 2 within the support plate 1. Thus, the battery 2 is maintained in position by the portion of the coil core 14 in abutting engagement therewith and the pressure of the lead plate 9 disposed thereagainst.

Both ends of the coil core 14 of the coil 3, and the stator of the electro-mechanical transducer are formed in overlapping position, when seen in plan view. The coil 3 is secured to the support plate 1 by fixing screws 19 and 20. The stator plate 17 is positioned on the surface of the support plate 1 in order to define a fixed gap between the portions 17a and 17b of the stator. An end-piece 18, for the stator, is secured to the support plate by a spot weld.

The stator 17 of the electro-mechanical step motor surrounds a rotor 21a, which rotor is formed of a diametrically oppositely poled magnet. Accordingly, as is explained in detail below, the stator effects an incremental rotation or stepping of the rotor 21a in a conventional manner so that the step motor, in effect, converts the low frequency timekeeping signals produced by the divider circuitry and applied to the core 3 into a rotational movement of the rotor 212.

The incremental rotation of the rotor 212 is reduced by a gear train to a specific rotational increment corresponding to actual time by means of a gear train, which gear train is illustrated in FIGS. 1, 2a and 5. The rotor 21a of the step motor is supported by a pinion 21 and, in response to an output signal applied every 2.5 seconds to the coil core, is rotatably stepped. The pinion 21 is rotatably disposed in bearings supported in the support plate 1 and third wheel bridge 8. The pinion 21 also supports a gear 21b, which gear is coupled to a fifth gear wheel 22b supported on a fifth pinion 22. Fifth pinion 22 is rotatably disposed in bearings formed in the support plate 1 and third wheel bridge 8, and is rotated in response to each stepping of the rotor 21a. In addition to gear wheel 22b, a gear 22a is supported on pinion 22, which gear is disposed in meshing engagement with fourth gear wheel 23b in order to transmit a rotary motion thereto. Fourth gear wheel 23b is supported by a pinion 23 and includes a fourth gear 23a constructed and arranged in the same manner as the fifth gear wheel, gear and pinion arrangement detailed above and imparts rotary motion to a third gear wheel 24b, pinion 24 and gear 24a, in the same manner discussed above. Accordingly, the fifth pinion, fourth pinion and third pinion are each supported by the support plate 1 and third wheel bridge 8, in order to impart to a center wheel 25b a predetermined rotary motion to effect the driving of the minute hand thereby. Center wheel 25b is rotatably disposed in an outer bearing, formed in the support plate, in meshing engagement with a minute wheel 28 in a conventional manner. Also, center wheel 25b is disposed on a cannon pinion 25, which pinion is disposed in an axle bearing 27 in the back surface of the support plate 1 to permit same to be freely rotated.

It is noted that the stator poles 17 are provided with a plurality of holes, such as hole 17c, for permitting the third gear wheel 24b and pinion 24 supporting same to be positioned within the hole in the stator thereby facilitating positioning of the respective pinion arrangement when the timepiece is assembled. Although the pinion 24 and third gear wheel supported thereby can be positioned in the same position as the minute wheel 28, the position of the minute wheel must take into account the position of the clutch wheel 30 and setting wheel 29, which wheels transmit the rotary motion of the stem 31 to the minute wheel. It is noted that if the minute wheel 28 is not positioned symetrically with respect to the longitudinal axis of the stem 31, the minute wheel 28 and battery 2 will be disposed in overlapping relationship when viewed in plan, thereby rendering it very difficult to remove the minute wheel 28.

Accordingly, in an exemplary embodiment, the gear train is positioned so that same is surrounded by the coil 3 and battery 2, to thereby provide an optimum distribution and positioning of the gear train. The gear wheels, and gears, of the back gear train, including fifth, fourth and third gear wheels, are therefore disposed in substantially overlapping relationship with respect to each other, as seen in plan view, and additionally, in substantially non-overlapping relationship with respect to the front gear train, to thereby provide a thinner and more compact electronic wristwatch movement.

Turning now to FIGS. 3 and 4, the regulating and reset lever mechanism of the miniaturized electronic timepiece, depicted in FIG. 1, is illustrated in detail. Regulating lever 32 is adapted to be displaced to a position 33, illustrated in phantom in FIG. 3. When the regulating lever 32 is displaced to position 33, an engaging portion 32a thereat is displaced to the position 33a, illustrated in phantom in FIG. 3, which position is in engagement with the fifth gear wheel 22a. The regulating lever is pivoted about a fixed pin 34, which pin is secured to the support plate 1. As is noted above, the fixed pin 34 is also utilized to fixably mount the positive lead plate 9 in position.

The tail portion 32b of the regulating lever 32 is resiliently biased in engagement with pin 35. A lever pin 36 is formed on regulating lever 32 and is positioned in abutting engagement with stem 31 to prevent the regulating lever 32 from being pivoted about pin 34 in response to the resilient biasing force applied by the pin 35 to the tail portion of the regulating lever. Additionally, the pin 34 is provided with a collar in the upper portion thereof, in which collar is engaged the regulating lever 32, to thereby insure that the regulating lever is maintained or fixed at a proper elevation with respect to the remaining components of the timepiece. Accordingly, in addition to providing a pivot for the regulating lever 32, the pin 34 fixes the elevation of the regulating lever with respect to the elevation of the remaining structural elements in the movement. Similarly, a portion 32c of the regulating lever 32 is positioned within a notch 37a formed in the third bride support 37 when the lever is disposed in a regulating position 33 in order to further insure that the regulating lever is disposed in proper elevational registration with respect to the elements in the electronic timepiece movement. It is necessary to maintain this elevational relationship between the engaging portion 32a of the regulating lever 32 and the gear wheel 22a of the gear train.

The regulating lever 32 is selectively displaced to position 33 by removing the stem 31 away from the regulating lever pin 36, to thereby pivot the engaging portion 32a of the regulating lever into engagement with gear wheel 22a and hence effect a regulation of the fifth wheel pinion 22. Simultaneously therewith, the divider circuit is reset to zero by the pivoting of the regulating lever into contact with reset pin 38, which pin is secured to the support plate 1. Additionally, an insulating frame 39 is provided for insulating the reset lead plate and for preventing same from being deformed when the timepiece is assembled. Moreover, it is possible for the insulating frame 39 to prevent other parts from being deformed during construction and also from preventing electrical contact between the close fitting elements, when such electrical contact should be avoided. Any looseness in the firt of the parts, or play, is prevented by providing an overlapping portion 39a of the insulated frame 39, which portion overlaps the projecting portion 37d of the third bridge support 37. Additionally, the insulating frame 39 is provided with suitable openings, such as opening 39b, for permitting the respective gear wheels and pinions to be positioned therein. For example, the manner in which the fourth gear wheel 23b and pinion 23 are oriented is by permitting the tenon to be fit into the opening 39b during assembly and permitting same to rest thereagainst until the third wheel bridge 8 is brought into position to pivotably secure the respective tenons.

Additionally, the instant invention provides for recesses 40 and 41 located in peripherally disposed notches 1e and 1f, respectively provided in support plate 1 to permit a dial to be readily secured to the support plate 1. As is illustrated in FIG. 2b, recesses 40 and 41 permit dial feet 42a and 42b, projecting from dial 42, to be disposed therein and secured by screws 43 and 44, which screws are disposed peripherally with respect to the dial 42. The openings for receiving the dial feet are disposed so that they respectively overlap the coil 3 and battery 2. Accordingly, the instant invention recognizes that the battery and coil although utilizing considerable space, as seen in plan view, do permit other elements to be elevationally disposed above and below these elements, such as under the curved under-portion of the battery. Similarly, the third wheel plate 8 is disposed in substantial overlap with the coil 3, as seen in plan view, thereby utilizing space in the movement that is otherwise wasted. Accordingly, by the configuration of the elements detailed above, and the configuration of the support plate for supporting these elements, a miniaturized quartz crystal electronic wristwatch movement is provided.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above construction 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.