JPH0535350Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a switching mechanism for pointer display type watches, in which a slip mechanism is not provided on the second wheel, and a part of the wheel train is disengaged when setting the hands. Regarding improvement of the method.

[Conventional technology]

Conventionally, many pointer display watches have adopted a method of slipping between the second wheel gear and the pinion when setting the hands, but this method has the disadvantage that it is difficult to manage slip torque and increases costs. For this reason, a method of disengaging the third wheel and second wheel has recently been put into practical use. As shown in Fig. 3, the lower part 3a of the third wheel & pinion 3 is supported by a lever 1 that is linked to the push and pull of the winding stem (not shown). 3 and center wheel 2 are disengaged.

[Problem that the invention attempts to solve]

This method has the advantages of eliminating the need for a slip mechanism on the second wheel, eliminating the need for strong force to turn the needle, and allowing the wheel and other parts to be made of inexpensive plastic, but has a major drawback. It was also equipped with As shown in Fig. 4, even after the third pinion 3b and the second gear 2c are disengaged, the third pinion 3b remains in the same state without rotating, so after turning the needle, the third pinion 3b remains in the same state. When the pinion 3b is meshed with the second gear 2c again, the second gear rotates so that the peak of the second gear fits into the valley of the third pinion, making it impossible to adjust it to an arbitrary position. For example, if the second gear 2c has 60 teeth, it can only be adjusted in 6 degree increments.

The purpose of this invention is to eliminate these drawbacks, and while maintaining the advantage of not requiring a slip mechanism for the second wheel, it attempts to make it possible to adjust the second wheel in small steps when setting the hands. It is something.

[Means for solving problems]

In order to solve the above problems, the present invention includes an electromechanical converter, a fourth wheel driven by the electromechanical converter, and a second wheel and pinion to which the minute hand is attached, decelerating the movement of the fourth wheel. A third wheel and pinion to transmit, a winding stem, a mechanism that holds the winding stem at multiple positions in the axial direction, a mechanism that transmits the rotation of the winding stem to the second wheel and pinion at a certain position positioned by the holding mechanism, etc. In the pointer display type timepiece, the third wheel is tilted when the rotation of the winding stem is transmitted to the second wheel, and is engaged with the second wheel while being engaged with the fourth wheel. It is characterized by being configured so that it can be removed.

[Effect]

With this configuration, after the hands are aligned, the third wheel is engaged with the fourth wheel again, and even if the third wheel rotates a little, it is transmitted to the second wheel at a reduced speed, so the second wheel rotates slightly. It will only rotate. In other words, the second wheel is adjusted in small steps to compensate for the deceleration caused by the third wheel.

〔Example〕

FIG. 1 shows an embodiment according to the invention. In the figure, 4 is a main plate, 5 is a gear train bridge, and 6 is a second wheel, with a minute hand 7 attached to its lower end. Reference numeral 8 indicates a third wheel, and the upper handle 8a is supported by a switching lever 9. The switching lever 9 is moved from the third wheel as shown in the figure by pulling out the winding stem (not shown) from the normal position to the needle alignment position. It operates to disengage the number gear 8c and the fourth wheel 10. When the winding stem is turned in this state, the second and third wheels are rotated by a gear train such as a gear wheel (not shown), but the fourth wheel & pinion 10 is rotated by the fifth wheel & pinion 11,
It does not move because it is engaged with the rotor 12 via. When the needle adjustment is completed and the winding stem is pushed into the normal position, the switching lever 9 moves to the left and the third gear 8c meshes with the fourth gear 10. At this time, the third gear 8c
If the phase of and the fourth kana 10b are not in alignment,
The third wheel rotates and fits. In this example, the number of teeth on the fourth pinion is 8, the third pinion has 48, the third pinion has 6,
Since the second gear is 60, the maximum angle that the third gear can rotate when pushing in the winding stem is 360 ÷ 48 ÷
2 = 3.75 degrees, and in the second wheel where the transmission is decelerated, it becomes 3.75 ÷ 60 x 6 = 0.375 degrees. This is only a 1/16 scale on the minute hand scale. The minute hand can be set in 0.75 degree increments, and the minute hand can be set in 1/8th increments.

FIG. 2 is a plan view showing the operation of the switching lever. The switching lever 9 has a pin 13 as its rotation axis.
The upper part of the third wheel & pinion 8 is supported by the hole a, and the tip of the arm 9b is in contact with the tip of the winding stem 14. The tip of the spring 9c is locked to the wall 4a of the main plate, and since a force is acting to rotate the switching lever clockwise, the winding stem 1
4 from the normal position shown in the figure to the needle alignment position, the third wheel & pinion 8 and the fourth pinion 10b are disengaged.

[Effect of idea]

According to the present invention, as mentioned above, since the engagement between the third wheel and the fourth wheel is released when setting the hands, there is no need to provide a slip mechanism on the second wheel, and the device can be manufactured at a low cost. Another advantage is that the second wheel can be corrected in small steps. The steps that can be corrected are the 1/8 scale on the minute scale, which means that the minute hand can be set to any desired position, and complaints about not being able to set the minute hand to the second hand no longer occur.

It goes without saying that the number of teeth on the number wheel is not limited to the value in the embodiment, and the mechanism such as the switching lever is not limited to the value in the embodiment.

[Brief explanation of the drawing]

Fig. 1: Cross-sectional view of the gear train part of the embodiment of the present invention, Fig. 2
Figure... Plan view of the switching mechanism of the embodiment of the present invention, Figure 3...
. . . Cross-sectional view of the conventional example, FIG. 4 . . . A diagram showing the meshing of the conventional example. 1, 9...Switching lever, 2,6...Second wheel,
3, 8... Third wheel, 4... Main plate, 5... Gear train bridge,
10... Fourth wheel, 14... Winding stem.

Claims (1)

[Scope of utility model registration request] an electromechanical converter, a fourth wheel driven by the electromechanical converter, a third wheel that decelerates and transmits the movement of the fourth wheel to the second wheel to which a minute hand is attached, a winding stem;
In a pointer display type timepiece comprising a mechanism for holding the winding stem at a plurality of positions in the axial direction, a mechanism for transmitting the rotation of the winding stem to the second wheel and pinion at a certain position determined by the holding mechanism, etc. , the third wheel and pinion is tilted in a state in which the rotation of the winding stem is transmitted to the second wheel and pinion, so that the third wheel and pinion is in mesh with the second wheel and pinion and is disengaged with the fourth wheel and pinion. A switching mechanism for watches.