JPS6356508B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a particularly thin and compact wheel train for a battery-powered timepiece.

Traditionally, in watches that use batteries, the size of the battery used is limited, and the shape of the battery is also generally limited to a round shape, making the entire watch thin and
There were limits to miniaturization. In particular, the outer diameter of ultra-thin movements for women is determined by the size of the second gear train and the outer diameter of the battery. The reason for this is that there usually needs to be a clearance of about 0.1 to 0.15 mm in plan between the second gear train, the outer diameter of the minute wheel, or the outer diameter of the hour wheel, whichever has the larger diameter, and the battery. Moreover, the battery is housed within the main plate of the movement. In addition, the conventional wheel train structure around the center wheel is normally rotatably supported on a central shaft 7 fixed to a main plate 5 or bridge 3, as shown in FIG. An hour wheel 2 rotatably supported on a wheel 1 is arranged, and the rear wheels of the hour wheel 2 and the minute wheel 1 are connected to a main plate 5,
It is determined by the receiver 3 or the dial 8.
However, with this structure, the slip portion of the minute wheel 1 becomes larger than the diameter of the center shaft 7 fixed to the main plate 5 or bridge 3, and if the diameter of the slip portion of the minute wheel 1 becomes large, the minute gear 1b becomes The outer diameter of the spring became large, making it impossible to reduce the gear train around the second wheel. Furthermore, as shown in FIG. 3, a structure has been considered in which the hour wheel 2 is supported by the inner hole of the hour wheel tube 6 provided on the main plate 5, and the minute wheel 1 is further supported by the inner hole of the hour wheel 2 and the bridge 3. There is. In this case, it is possible to reduce the diameter of the minute wheel 1 because it does not require a hole for passing the central shaft, but the diameter of the pinion 1a can be further reduced so that the root diameter D ₃ is equal to the diameter D ₁ of the needle attachment part or If the diameter is smaller than the diameter D 2 of the part supported by the hour wheel ₂ or the diameter D ₃ of the slip part with the minute tooth 1, tooth profile irregularities will appear on the outer periphery, resulting in functional and assembly problems. However, there were limits to the reduction of the diameter of the kana. Moreover, especially in thin battery-powered watches, the thickness of the battery is extremely thin, so in order to increase the capacity of the battery, it is necessary to increase the outer diameter.
For this reason, it has been difficult to realize an ultra-thin and compact watch.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an object of the present invention is to reduce the diameter of the wheel train around the second wheel, thereby making it possible to realize a thin and compact battery-powered timepiece.

The present invention will be explained in detail below with reference to the drawings. 1st
In the figure, the minute wheel 1 is supported by an upper handle frame 4 of a receiver 3 which is fixed to the main plate 5 by a fixable means, and an hour wheel 2 which is rotatably guided by an hour wheel frame 6 driven into the main plate 5. has been done.

Further, the minute wheel 1 has a structure in which a bush 1b is fixed to the minute wheel pinion 1a, and a slip mechanism of the minute wheel 1 is constituted by the spring properties of the bush 1d and the mid portion of the minute gear 1b. Furthermore, a needle attachment bush 1c is fixed to the minute wheel pinion 1a. By adopting such a structure, the tooth profile module of the minute wheel pinion 1a can be made as small as possible within the processable range. Furthermore, since the slip portion of the minute wheel 1 has a structure that does not use the conventional center shaft, the diameter can also be reduced, and therefore the outer diameter of the minute wheel 1b can also be reduced. Moreover, by reducing the diameter of each part, the contact area of the bearing part is reduced, and torque loss can be lowered than in the conventional wheel train structure around the second wheel. Furthermore, since the second wheel train is arranged between the main plate 5 and the bridge 3, it can be assembled at the same time as the second and subsequent wheel trains, improving ease of assembly.

As described above, according to the present invention, it is possible to reduce the diameter of the wheel train around the second wheel, thereby making it possible to realize a particularly thin and compact battery watch. It has a tremendous effect of being good for sex.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a second wheel train structure according to the present invention, and FIG. 2 is a sectional view of a conventional second wheel train structure. 1... Minute wheel, 2... Hourly wheel, 3... Uke, 5... Main plate.

Claims (1)

[Claims] 1. In a watch having a wheel train structure in which the hour wheel is rotatably guided by the main plate or a support member fixed to the main plate, and the minute wheel is supported by the hour wheel and the train wheel bridge, the minute wheel may be a minute wheel. a minute gear guide bushing that is driven into the minute wheel pinion and guides the minute gear on its outer periphery, a minute gear that is pushed into the minute gear guide bushing with a constant slip torque, and a minute gear driven into the minute wheel pinion. 1. A wheel train structure for a timepiece, comprising at least four composite parts: a hand mounting bush having a part that is inserted into the hub and is supported by the hour wheel, and a hand mounting part.