JPH0247515Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a clock main shaft device suitable for use in a travel alarm clock.

<Prior art> (Fig. 5) Traditionally, the long hand L and short hand S of a watch are driven by rotating the long hand L fixed at the tip by the main shaft M, and rotating the main shaft M fixed in the middle of the main shaft M. Rotation of the main shaft M is achieved by interposing large and small gears I and i coaxially fixed between the pinion g rotated by the small gear g and the short hand gear G coaxially rotatably mounted on the main shaft M. A widely used method is to reduce the speed and transmit it to the short hand gear G, and to rotate the short hand S fixed to the short hand gear G via a shaft tube T.

This type of model was devised to reduce the number of parts as much as possible and ensure reliable operation with small torque, and until now it has been thought that this design sufficiently achieves the purpose. .

<Problems to be solved by the invention> In the conventional type described above, the main part of the mechanism K is installed between the two frame plates F and F', and the part above the pinion g is placed upward. exposed on the frame plate F of
A dial D is installed on top of the clock to form a clock.

In such a configuration, the main shaft M must penetrate the entire width of the watch device as shown in Fig. 5, and therefore the main shaft M must be long. . The fact that the spindle M is long means that there is a problem with the economy of materials, and it also means that the long spindle M must be manufactured with quite high precision. At the same time, high processing accuracy is required at the assembly processing stage as well.

Naturally, when the main shaft M is long as described above, in order to prevent threading between the main shaft M and the shaft cylinder T, a higher level of processing technology is required for each part.

However, the main purpose of today's watch manufacturing is to obtain cheaper finished products by pursuing easier assembly, easier parts manufacturing, etc., and the main shaft M made of steel is manufactured with high precision. To say so is contrary to this purpose. Such a problem would be solved if high-precision parts for the rotating shaft could be obtained inexpensively and in large quantities, but such a situation cannot be considered as a real problem.

Therefore, we stopped pursuing such precision and
If a certain degree of machining accuracy can be achieved, there is actually a need for a new device that can ultimately provide functional satisfaction, and this project seeks to solve such problems.

<Means for solving the problem> In this project, in order to eliminate the drawback of the conventional product called the long steel main shaft M, we stopped using the conventional product main shaft M, and instead A shaft that corresponds to a conventional main shaft is formed by three parts: a shaft with a length that slightly protrudes, a synthetic resin substrate fixed to the tip of the shaft, and a shaft rod.

Furthermore, the board is equipped with a gear at the bottom, and the shaft rod fixed to the board has a protruding cylindrical part. After the synthetic resin board is fixed to the steel shaft, the synthetic resin shaft rod is fixed to the board. to get the axis. In this case, since it is inevitable that all of these fixed parts have some play, the play itself serves as a means to prevent parts from becoming scratched.

The shaft and the board are fixed using a caulking cap, and the board and the shaft rod are fixed by a synthetic resin molded structure that allows the parts to be connected and fixed.

<Function> According to this proposal, the main shaft, which was previously a single steel part, is now made up of three parts: a steel shaft, a synthetic resin board, and a shaft rod, allowing for the parts processing required for conventional products. We succeeded in eliminating the high precision of assembly and at the same time creating a device that is less prone to scratching of parts.

<Embodiment> (FIGS. 1 to 3) FIGS. 1 to 3 show specific embodiments of the apparatus according to the present invention. To explain its structure according to the drawings, 1 is a steel shaft, 2 is a synthetic resin base fixed to the tip of the shaft 1, 3 is a small gear molded integrally with the base plate 2, and 4 is fixed to the base plate 2. The synthetic resin shaft rod 6 is a short hand gear fixed to the lower end of the shaft tube 5 fitted into the protruding cylindrical portion 4' of the shaft rod 4, and is rotatable with respect to the shaft rod 4. in a state.

The rotation of the small gear 3 is transmitted to the short hand gear 6 by the small intermediate gear i coaxial with the large intermediate gear I meshing with the small gear 3 meshing with the short hand gear 6. The meshing state of each gear is as shown in Fig. 4, and their ratios are: small gear 3: large intermediate gear I = 3:8, small intermediate gear i: short hand gear 6 = 2:9, This ensures that the hour hand gear 6 rotates 30 degrees with respect to the 360 degree rotation of the small gear 3.

In Figures 1 and 2, L indicates a long hand fixed to the tip of the protruding cylindrical portion 4' of the shaft rod 4, S indicates a short hand fixed to the tip of the shaft cylinder 5, and F indicates the main part of the mechanism. It is a frame board to protect and support the

Next, to explain the mutual fixing of the shaft 1 and the base plate 2, and the base plate 2 and the shaft rod 4, as shown in FIG.
A reduced diameter part 1' is provided at the tip of the substrate 2.
A caulking cap 7 is fitted onto the tip of the shaft 1 protruding through the shaft 1, and the reduced diameter portion 1' is press-fitted into the central hole 7' of the caulking cap 7, whereby the shaft 1 and the substrate 2 are fixed to each other. 8 is a protection plate for the small gear 3, and 9 is an elastic plate installed between the frame plate F and the protection plate 8.

Next, the mutual fixation of the board 2 and the shaft rod 4 is performed by the board 4
A protrusion 10 protruding from one end is inserted into a fixing hole 11 formed in the shaft rod 4, and an engagement piece 12 protruding from the other end of the substrate 2 is inserted into an engagement recess 13 of the shaft rod 4. Complete fixation. At this time, the protruding end of the caulking cap 7 is accommodated in the shaft 4, aligns the center line of the shaft 4 with respect to the shaft 1, and supports the lateral force applied to the shaft 4.

The base plate 2 and the shaft 4 can be fixed to each other by inserting the protrusion 10 into the fixing hole 11 of the shaft 4 and the caulking cap 7 into the recess of the shaft 4, and then pushing it down to engage the engagement piece 12. It sinks into the recess 13 and is automatically fixed.

The mutual relationship of these parts is clearly shown in the exploded perspective view of FIG.

<Description of the operation in the embodiment> According to the device of the present invention completed as described above, the rotation of the shaft 1 is transmitted to the shaft rod 4 via the substrate 2 fixed thereto, and the rotation of the shaft 1 is transmitted to the shaft rod 4 through the substrate 2 fixed thereto. While rotating the long hand L, the small gear 3 integrated with the base plate 2,
By rotating the meshing large intermediate gear I, the small intermediate gear i coaxial with it rotates the hour hand gear 6 that meshes with it, and is fixed to the tip of the shaft cylinder 5 integral with the hour hand gear 6. The hour hand S can be rotated.

In this case, the shaft cylinder 5 fitted onto the shaft rod 4 is reliably supported by the shaft 1 via the shaft rod 4 as described above.

<Effects of the invention> According to the present invention, the base plate 2 and the shaft rod 4 are fixed to the tip of the shaft 1, and the long hand L is fixed to the tip of the shaft rod 4, so that the thread between the shaft tube 5 and the shaft rod 4 is fixed. is less likely to occur, and the diameter of the shaft rod 4 is much thicker than the main shaft M of the conventional product or the shaft 1 according to the present invention, so it is easier to attach and fix the long hand L to the shaft rod 4 than before, and the special Parts: board 2 and shaft 4
Since it is made of synthetic resin including the small gear 2, mass production is possible.

As a result, it is possible to obtain a large quantity of devices that are cheaper and easier to manufacture than conventional devices without having to worry about accuracy in parts production or assembly.

[Brief explanation of the drawing]

Fig. 1 is a front view of the proposed device, Fig. 2 is a sectional view of Fig. 1, Fig. 3 is an exploded perspective view of main parts, and Fig. 4 is a plan view showing the meshing state of the gears used in the proposed device. FIG. 5 is a conceptual front view of a conventional product. 1... shaft, 2... board, 3... small gear, 4...
Shaft rod, 5... Gear for hour hand, 6... Shaft cylinder, 7... Caulking cap, 8... Protection plate, 9... Elastic plate, 1
0...Protrusion, 11...Fixing hole, 12...Engaging piece,
13... Engagement recess, I... Large intermediate gear, i... Small intermediate gear, L... Long hand, S... Short hand, F... Frame plate.

Claims (1)

[Scope of utility model registration request] The reduced diameter part 1' at the tip of the shaft 1 protruding from the frame plate F penetrates the board having the pinion 3 on the lower surface, and the elastic disc 9 interposed between the board 2 and the frame plate F is connected to the pinion 2.
The caulking cap is fitted onto the reduced diameter portion 1' of the shaft 1 protruding from the base plate 2, and the base plate 2 is fitted into the fixing hole 11 of the shaft rod 4 having the protruding cylindrical portion 4'. A main shaft device for a watch, in which a protrusion 10 is inserted and an engaging piece 12 of a base plate 2 is recessed into an engaging recess 13 of a shaft rod 4.