Construction of an Analogue Crystal Wrist Watch

This invention relates to the construction of the movement of an ultra-small type analogue crystal wrist watch.

With rapid popularization of high precision analogue wrist watches of late, demands for smaller and thinner analogue wrist watches are increasing. However, since the battery cell, crystal oscillating element and step motor which constitute principal components of the analogue crystal wrist watch occupy a relatively large space both in horizontal and vertical directions, respectively, it is not possible to dispose these components on other respectively associated wrist watch components. For the reason, in order to reduce the thickness of the movement of an analogue crystal wrist watch, separate spaces for accommodating the battery cell and crystal oscillating element and the drive coil constituting the step motor should be provided in the movement so that these components can be disposed not to overlap one upon another in the movement and the movement also requires other spaces for accommodating other timepiece components which inevitably increases the size of the timepiece and makes it impossible to realize an ultra-small type timepiece. Thus, an ultra-small type thin analogue crystal wrist watch such as a woman's bracelet watch has been difficult to be produced up to date.

Therefore, the purpose of the present invention is to make it possible to realize an ultra-small type analogue crystal wrist watch by disposing the crystal oscillating element, the reset lever interlocked with the stem and the reset lever holder adapted to regulate the clearances above and below the reset lever in different heights in the same space to thereby realize an ultra-small type analogue crystal wrist watch.

In order to attain the above purpose, according to the present invention, the battery cell, crystal oscillating element and drive coil which constitute principal components of the movement are disposed in different horizontal spaces along and inwardly of the periphery of the movement, the wheel train of the hand indicating means is positioned in the center of the movement and the crystal oscillating element and the reset lever adapted to be interlocked with the stem constituting the hand correction means for resetting the frequency division circuit are disposed in different heights in the common horizontal space.

According to the present invention, there has been provided an analogue crystal wrist watch which essentially comprises a base plate, a power source battery cell provided on said base plate for providing energy to the watch circuit of said wrist watch, a crystal oscillating element adapted to receive energy from said power source battery cell and generate a signal of a predetermined frequency, an electronic circuit for dividing the frequency of the output signal of said crystal oscillating element, a step motor comprising a drive coil connected to said electronic circuit, a hand indication means driven by said step motor, an external operation member constituting a hand correction means for correcting said hand indication means, a reset lever interlocked with said external operation member to reset said electronic circuit, said crystal oscillating element and reset lever being disposed in the same horizontal space and said base plate having an oval shape as seen in plan.

The above and other objects and attendant advantages of the present invention will be more readily apparent to those skilled in the art from a reading of the following detailed description in conjunction with the accompanying drawings which show one preferred embodiment of the present invention for illustration purpose only, but not for limiting the scope of the same in any way.

FIG. 1 is a plan view of the movement of one embodiment of analogue crystal wrist watch of the present invention;

FIG. 2 is a fragmentary vertically sectional view of said movement as shown in FIG. 1;

FIG. 3 is an exploded vertically sectional view of the reset switch of said movement as shown in FIG. 1; and

FIG. 4 is a vertically sectional view of the battery cell and its associated parts as shown in FIG. 3.

The present invention will be now described referring to the accompanying drawings which show one preferred embodiment of the analogue crystal wrist watch of the invention. First referring to FIG. 1 of the accompanying drawings, reference numeral 1 denotes the movement base plate which has an oval shape most suitable for a woman's bracelet watch and a battery cell 2, a crystal oscillating element 3, a stator 4 and a drive coil 5 are disposed along and inwardly of the periphery of the base plate 1. The stator 4 and drive coil 5 constitute a step motor. Provided in the center of the movement are a fifth wheel - pinion 7, a fourth wheel - pinion 8, a eighth wheel - pinion 9 and a center wheel 10 of a hand indication means driven by the rotor 6 of the step motor. These wheel - pinions and wheel are the principal components of the hand indication means. Disposed in the space defined by the battery cell 2, crystal oscillating element 3 and drive coil 5 above the wheel train is a printed circuit board 13 on which electronic circuit elements such as a circuit 11 and a trimmer capacitor 12 are mounted. A reset lever 14 is disposed below the crystal oscillating element 3. The reset lever 14 is rotated in the clockwise direction about the rotary shaft 14a through a setting lever 16 by pulling a stem 15 until the contact 14b of the reset lever 14 comes into contact with a reset pin 17 secured to the printed circuit board 13. Furthermore, the reset pin 17 is connected to the reset terminal of the electronic circuit 11 by means of a pattern wiring (not shown). And the positive pole of the battery cell 2 is grounded to the base plate 1 and the base plate 1 and reset lever 14 are in electrically continuity. That is, in the normal position of the stem 15, the reset terminal of the circuit 11 is open and the reset lever 14 comes into contact with the reset pin 17 by pulling (not shown) the stem 15 whereby the reset switch constituted by the reset lever 14 and reset pin 17 turns ON and is electrically connected to the reset terminal VDD of the electronic circuit 11. As a result, the frequency division circuit within the circuit 11 is reset and no drive current flows through the drive coil which is "the economy in power consumption condition". When the stem 15 is moved from its normal position to the pulled position in which the stem aligns with one of the hands, the reset lever 14 abuts against the addendum 8a on the fourth wheel - pinion 8 by means of the brake portion 14c of the reset lever 14 to thereby lock the fourth wheel - pinion 8 in position. Reference numeral 18 denotes the battery cell support 18 which positions the battery 2 in horizon. The upper surface of the battery cell support 18 is provided with a fast and slow adjustment indication mark 18a to use the space effectively. Reference numeral 19 denotes the cathode supporting spring for the battery cell 2.

FIG. 2 is a fragmentary vertically sectional view of the area containing the crystal oscillating element 3 and reset lever 14. The crystal oscillating element 3 has an oval cross-sectional shape to minimize the area to be occupied by the crystal oscillating element. The crystal oscillating element 3 is resiliently supported by a crystal oscillating element supporting spring 20 secured to the printed circuit board 13 and has a crystal oscillating support element 21 attached to the undersurface which is formed of soft shock absorption material such as silicone rubber in order to increase shock absorption ability of the crystal oscillating element 3. Furthermore, a plastic reset lever holder 22 and the reset lever 14 are disposed in spaced overlying relationship in the same space below the crystal oscillating element support 21. The reset lever 14 concurrently serves as the brake for the fourth wheel - pinion 8 in cooperation with the reset lever holder 22 when the stem 15 is aligned with one of the hands. Reference numeral 23 denotes a reset lever holding screw for securing the reset lever holder to the base plate 1.

FIG. 3 is a cross-sectional view of the reset switch of the movement of the present invention and by pulling the stem 15 in one or the other direction, the contact 14b of the reset lever 14 comes to contact with and disengages from the contact 17a of the reset pin 17.

FIG. 4 is a vertically sectional view of the battery cell and its associated parts and the battery cell 2 is controlled in its horizontal position by the battery cell support 18 and the cathode supporting spring 20 is controlled in its horizontal position at two points by a boss 18b and a projection 18c, respectively. The battery cell support 18 is positioned on the printed circuit board 13 by means of holes 13a and 13b. Reference numeral 24 denotes a battery cell holding screw which secures the battery cell support 18 and cathode supporting spring 19 to the printed circuit board 13. Thus, the positions of the battery cell 2 and cathode supporting spring 19 are controlled by the battery cell support 18 and the connection between the cathode supporting spring 19 and the pattern wiring on the printed circuit board 13 is effected in a narrow space.

As mentioned hereinabove, according to the present invention, the reset lever which is interlocked with the stem, resets the frequency division circuit of the electronic circuit and includes the reset switch contact which is disposed in spaced overlapping relationship to the crystal oscillating element in the common plane and accordingly, the rotary shaft of the reset lever and the crystal oscillating element are disposed in different heights in the common plane.

Therefore, according to the present invention, in order to provide an ultra-small type and thin analogue crystal wrist watch such as a woman's bracelet watch, the movement has an oval shape as seen in plan and the crystal oscillating element constitutes one of the constituent components of the movement. The battery cell, crystal oscillating element and drive coil are distributed along and inwardly of the periphery of the base plate which has a shape most suitable for a small type timepiece, the wheel train of the hand indication means and electronic circuit elements are positioned in the space defined by the battery cell, crystal oscillating element and drive coil, the reset lever which has the contact adapted to make contact with the reset switch for resetting the frequency division circuit of the electronic circuit to the "economy in power consumption position" in cooperation with the stem of the hand correction means and setting lever is positioned right below the crystal oscillating element, and the braking action for prevention of the rotation of the rotor is obtained when the reset lever is aligned with one of the hands. Thus, the space exclusively used for the reset lever as required in the conventional timepiece can be eliminated and since the crystal oscillating element and reset lever can be provided in the common same space, the space can be fully utilized whereby the timepiece can be easily designed. And as to the thickness of the movement, since the printed circuit board is provided with the recess for receiving the crystal oscillating element, the thickness of the crystal oscillating element is made small as much as possible and the cross-sectional configuration of the crystal oscillating element is oval whereby the thickness of the movement will not increase even when the crystal oscillating element and reset lever are disposed one upon another in spaced relationship.

While one embodiment of the invention has been shown and described in detail, it will be understood that the same is for illustration purpose only and not to be taken as a definition of the invention, reference being had for this purpose to the appended claims.