JPS6346863Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a structure that prevents the minute hand from fluctuating in a pointer display type electronic watch.

Traditionally, pointer display type electronic watches operate the seconds, minutes, hours, etc. hands by decelerating the rotation of a step motor using a gear train, and a spring type mechanical watch transmits the torque of the barrel wheel to the balance wheel. Unlike models that have minute and second hands in the middle, there is usually almost no torque, so the hands tend to fluctuate. For this reason, there are ways to reduce the fluctuation of the second hand by tightening the backlash of the gear or pressing the second wheel pressing spring against the shaft of the second hand. The hour hand was prevented from fluctuating by applying the brakes. In addition, in order to prevent the minute hand from fluctuating, the hour wheel washer passed through the hour wheel and served as a brake for the second wheel to which the minute hand was attached. Fluctuations are likely to occur due to shocks received, and especially immediately after setting the hands, the balance from the second wheel to the hour wheel is not clogged, so the minute hand will move with the slightest shock.This is to prevent this. Although efforts were made to reduce the fluctuation of the gears and reduce the play of the center wheel and hour wheel, it was difficult to completely prevent fluctuation.

The present invention aims to eliminate such drawbacks and provide a simple and low-cost structure for preventing minute hand fluctuation.

The minute hand fluctuation prevention structure of an electronic timepiece according to the present invention includes a minute hand wheel which is supported by a base frame and a gear train bridge and has a minute hand attached to a shaft part that projects from the base frame, and a minute hand wheel which is integrally formed with a tooth part and engages with the shaft part. In the minute hand fluctuation prevention structure of a pointer display type electronic watch having an hour wheel to which an hour hand is attached to a mating pipe portion, the shaft portion of the minute hand wheel is provided with a stepped portion for positioning the hour wheel in an axial direction. The hour wheel has the teeth disposed between the base frame and a dial mounted on the base frame, and has a slight clearance between the hour wheel and the base frame so that the hour wheel has a slight clearance between the base frame and the dial plate attached to the base frame. The present invention is characterized in that a dial washer is mounted which is in contact with the stepped portion and has a deflection between the dial plate and the hour wheel.

An example of this will be explained below with reference to the drawings.
In FIG. 1, a rotor 6, a fifth wheel & pinion 5, a fourth wheel & pinion 4,
The third wheel 3, the second wheel 2 which is the minute wheel, and the minute wheel 8 are bearings, and the minute pinion 8a is located on the dial side of the main plate 1 and meshes with the teeth 9b of the hour wheel 9. There is. The dial washer 11 is attached with a deflection between the dial plate 10 fixed to the main plate and the toothed part 9b of the hour wheel 9,
It pushes the hour wheel toward the main plate and provides braking force. Here, hour wheel 9 is pipe 9a and number 2 is 2a.
The spring force of the dial washer engages with the shaft 2a of the second wheel, and the spring force of the dial press presses against the step 2b provided on the shaft of the second wheel, thereby determining the position in the axial direction. The toothed portion 9b of the hour wheel is configured to have a clearance K between it and the main plate 1. Therefore, the force of the dial is also applied to the second wheel, and the stepped portion 2c of the upper tenon of the second wheel presses against the second hole stone 12 of the gear train bridge 7 and receives the force. Reference numeral 13 denotes a seconds chronograph wheel, which is supported by a seconds chronograph receiver 14 and the second wheel upper hole stone 12, and whose upper tenon tip is pressurized by a seconds chronograph wheel spring 15 to move the seconds chronograph hand 1.
6 is prevented from fluctuating, and is driven by a chronograph wheel train (not shown) that is separate from the timepiece wheel train. 17 is a minute hand, 18 is an hour hand, which indicates the minutes and hours, and a small second hand 19 attached to the lower tenon of the fourth wheel 4 indicates the seconds of the normal time. Further, the center wheel 2 is engaged with the pinion so that it can slip, and has the known function of slipping when setting the hands.

The configuration of the embodiment is as described above, and the driving force from the rotor 6 is transmitted to the hour wheel 9 in seconds.
The minutes and hours are displayed, but since the braking force of the hand washer 11 is applied to the hour wheel 9 and the second wheel 2 at the same time, fluctuations in the minute and hour hands are suppressed and the hands cannot be set like a conventional watch. The minute hand does not wobble, even after the minute has started. Here, there is a gap K between the hour wheel and the main plate, but this value is calculated from the hour hand 18 to the hour wheel 9.
When the gear train bridge 7 is deflected by the force applied through the center wheel and pinion when pushing into the wheel, the gear part 9b of the hour wheel hits the main plate, and due to the rigidity of the main plate, excessive force is applied to the train bridge and center wheel. It is set so that it does not apply.

As described below, in the present invention, the hour wheel that engages with the shaft of the minute wheel has its teeth disposed between the base frame and the dial, and the teeth between the dial and the hour wheel. The flexible hand washer is pressed against the stepped part of the minute wheel.
By applying the braking force from the spring force of the dial washer to the hour wheel as well as the minute wheel, there is no need to provide a dedicated spring for the second wheel, and the hour wheel and second wheel can be connected using the conventional dial washer. It has a simple structure that applies a brake at the same time to eliminate fluctuations in the minute and hour hands, and the braking force can be easily adjusted by changing the amount of bending of the dial washer depending on the size of the hands. Also,
The force applied to the minute wheel when the hour hand is pushed in is suppressed by the teeth of the hour wheel hitting the base frame. Since there is a gap between the wheel and the main plate, there is no need for groove grinding to prevent ringing due to oil between the hour wheel and the main plate, which was necessary in the conventional structure where the hour wheel was in contact with the main plate, which is also effective from a processing perspective. is large.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention. 1... Main plate, 2... Second wheel, 7... Gear train bridge, 9
...hour wheel, 11...hand wheel.

Claims (1)

[Scope of utility model registration request] A minute wheel has a minute hand attached to a shaft part that is supported by a base frame and a gear train bridge and projects from the base frame, and an hour wheel has an hour hand attached to a pipe part that is integrally formed with a tooth part and engages with the shaft part. In the minute hand fluctuation prevention structure of a pointer display type electronic watch, the shaft portion of the minute hand wheel is provided with a stepped portion for positioning the axial direction of the hour wheel, and the hour wheel is in contact with the base frame. The tooth portion is arranged between the dial plate mounted on the base frame, and the tooth portion is abutted against the step portion of the minute wheel with a slight gap between the dial plate and the dial plate attached to the base frame. A minute hand fluctuation prevention structure for an electronic timepiece, characterized in that a flexible hand washer is attached between the hour wheel and the hour wheel.