JPS6329264Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field] This invention relates to a slip mechanism for a watch.

[Background technology]

In the past, we have proposed a slip mechanism for a watch that has a structure as shown in FIG. 1, which can reduce the number of parts and reduce the difference in slip torque. That is, the transmission wheel 2' has a transmission wheel 2' having internal teeth 1' on its inner peripheral surface, a pinion 3' located coaxially with the transmission wheel 2', and a ratchet tooth 4' that meshes with the internal teeth 1'.
The pinion 3' and the elastic ring 5' are connected via a connecting piece 6' at a position facing the ratchet teeth 4'. However, with this structure, the ratchet teeth 4' are supported on both sides by the elastic ring 5', so the difference in torque can be reduced even when slipping in either the forward or reverse direction. When a rotational force is gradually applied to the pinion 3' to cause the rotation, the ratchet tooth 4' does not rotate even if the pinion 3' and the connecting piece 6' rotate, and the elastic ring 5' eventually twists, as shown by the broken line. If the ratchet teeth 4' do not accurately follow the pinion 3', the time cannot be set accurately.

[Purpose of invention]

Therefore, the object of this invention is to provide a slip mechanism in which the ratchet teeth can accurately follow each other and allow accurate time setting.

[Disclosure of invention]

The slip mechanism of a watch according to this invention has a transmission wheel having internal teeth on the inner circumference, a pinion located coaxially with the transmission wheel, and a ratchet tooth that meshes with the internal teeth. In a slip mechanism for a watch, in which the pinion and the elastic ring are connected at a position opposite to the ratchet teeth, the pinion and the elastic ring are used as guide means for guiding the diametrical displacement of the ratchet teeth. It is characterized by being composed of.

(Embodiment) An embodiment of the present invention is shown in FIGS. 3 to 5. That is, the transmission wheel 2 is formed by providing a tooth forming part on the outer periphery of a disc 9, and a tooth part 10 that meshes with the pinion of the second hand wheel of a watch is formed on the outer periphery of the tooth forming part. Internal teeth 1 are provided on the inner periphery. The cylindrical pinion 3 has a transmission pinion portion 7 that meshes with the minute wheel of the timepiece, and is slidably attached to the transmission wheel 2 by means of ratchet teeth, which will be described later. Numeral 4 is a ratchet tooth having a plurality of triangular claws, and is provided on the outer periphery of an elastic ring 5 arranged along the inner periphery of the transmission wheel 2. This elastic ring 5 is connected to the pinion 3 via a connecting piece 6 at a position opposite to the ratchet teeth 4. Further, on the inner circumference of the elastic ring 5, an engagement protrusion 11 having a circular cross section is provided at a position passing through the central axis of the ratchet tooth 4, together with a connecting rib 12 whose width is narrower than the diameter of the engagement protrusion 11. A trapezoidal protrusion 13 is provided at the center of which is provided with a ratchet tooth 4, that is, the engagement protrusion 11 is configured such that it can guide only the diametrical displacement of the engagement protrusion 11.
An engagement groove 14 having a width substantially equal to the diameter of the engagement groove 14 is formed. That is, the pinion 3 and the elastic ring 5 constitute a guide means by which the radial displacement of the ratchet teeth 4 is guided. The elastic ring 5 is then elastically deformed and assembled into the transmission wheel 2, and the ratchet teeth 4 are elastically engaged with the internal teeth 1. At this time transmission car 2 and kana 3
It is located coaxially with. FIG. 5 is a sectional view, and the shaft body 1 is inserted into the insertion holes 15 and 16 of the transmission wheel 2 and pinion 3.
7 is rotatably inserted.

In addition, the elastic ring 5 having the ratchet teeth 4 and the engaging protrusion 11, the connecting piece 6, and the pinion 3 may be integrally molded from plastic, or if it is difficult to process them, the method shown in FIGS. 6a and 6b may be used. As shown, the elastic ring 5'' and the pinion 3'' are separated, and the elastic ring 5'' is provided with an engagement boss 11'' corresponding to the engagement protrusion 11 and a connection boss 6'' corresponding to the connection piece 6. A flange 16 large enough to cover the elastic ring 5'' is provided at the lower part of the pinion 3'', and an engagement groove 14'' corresponding to the engagement groove 14 and a connection hole 6 for the connection piece 6 are bored. may be set. In this case, the flange 16 also has the function of preventing the ratchet teeth 4'' and the elastic ring 5'' from lifting up.

(Operation) To explain the operation of the slip mechanism configured as above, the transmission wheel 2 is rotated by the drive of the second hand wheel, and the pinion 3 is driven via the ratchet teeth 3 to transmit the rotation to the minute wheel. When setting the time, set the ratchet tooth 4 against the internal tooth 1 of the transmission wheel 2.
Rotate Kana 3 while slipping. In this slipping operation, the elastic displacement of the ratchet tooth 3 in the diametrical direction is guided by the engagement groove 14 formed in the pinion 3, so the elastic ring 5 is twisted and the ratchet tooth 4 does not accurately follow the pinion 3. This phenomenon does not occur.

[Effect of idea]

In this invention, the guide means by which the diametrical displacement of the ratchet teeth is guided is composed of a pinion and an elastic ring, so that even if the ratchet teeth are elastically displaced during the slip operation, the elastic ring with the ratchet teeth will not be twisted. Therefore, the ratchet teeth can accurately follow the rotation of the pinion, providing a slip mechanism that allows accurate time setting.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the conventional example, Fig. 2 is an enlarged view of part A, Fig. 3 is a plan view of the embodiment of the present invention, Fig. 4 is an enlarged view of part B, and Fig. 5 is an enlarged view of part A of Fig. 3. Sectional view, No. 6
Figure 7 is an exploded plan view of another embodiment of the present invention.
The figure is a sectional view thereof. 1... Internal teeth, 2... Transmission wheel, 3... Kana, 4...
... Ratchet tooth, 5 ... Elastic ring, 6 ... Connection piece, 11, 14 ... Guide means.

Claims (1)

[Scope of utility model registration request] A transmission wheel having internal teeth on its inner peripheral surface, a pinion located coaxially with the transmission wheel, and an elastic ring having ratchet teeth that mesh with the internal teeth and disposed along the inner periphery of the transmission wheel. A timepiece characterized in that, in a slip mechanism of a watch in which a pinion and an elastic ring are connected at a position opposite to a ratchet tooth, a guide means for guiding the displacement of the ratchet tooth in a diametrical direction is constituted by the pinion and the elastic ring. slip mechanism.