JPS6132383Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an external operation switching mechanism for a wristwatch, and provides a thin wristwatch.

The description will be given below based on the drawings. FIG. 1 is a sectional view of a main part of an external operation switching mechanism of a wristwatch according to the present invention. The mandarin duck 3 placed on the upper surface of the main plate 1 that determines the basic thickness of the movement, that is, in the direction of the back cover 6, is attached to the toothed part 2 of the winding stem 2 at the neck part 3a.
c and the small diameter portion 2b. Mandarin pin 3b planted on Mandarin duck 3
is a back presser 4 that presses the mandarin duck 3 in one direction of the base plate.
The winding stem 2 is engaged with the two small holes 4a in its respective states to perform a click operation when the winding stem 2 is pulled out or pushed in. The upper surface of the pressing portion of the back presser 4 is set to almost match the upper surface of the movement, with the same minute dimension, which is a fraction of the thickness of the back presser 4, being the same. 1a
4b is a pin installed in the main plate 1 that is the center of rotation of the mandarin duck 3, 4b is a screw that fixes the back presser 4 to the main plate 1, and 7 is a dial plate. A is neck 3 of mandarin duck 3
A shows the amount of engagement between a and the stepped part of the winding stem 2, and B shows the top surface and back cover of the movement, excluding other parts not shown, which may protrude by a small area. It shows the amount of gap between 6 and 6.

FIG. 2 is a sectional view of the main part at a different position from FIG. 1. The winding stem 2 has a large-diameter portion 2a that is loosely fitted into a horizontal hole in the main plate 1, meshes with the small iron wheel 5, and has a neck portion 3a of the mandarin duck 3 between a toothed portion 2c whose outer diameter is approximately equal to the large-diameter portion 2a. There is provided a small diameter portion 2b overlapping with each other. In addition, in the tooth portion 2c, in order to prevent the tooth profile from reaching the small diameter portion 2b, the bottom of the tooth portion 2c has a shape that rises with a curvature near the portion approaching the small diameter portion 2b, as shown in the figure. There is. The small iron car 5 is rotatably attached to a switching lever 5b placed on the main plate 1 with studs 5a.

The step part on the small diameter part 2b of the winding stem 2 and the mandarin duck 3
The amount of engagement with the neck portion 3a is set parallel to the thickness direction as shown in FIG. 1, and is a dimension represented by A. On the other hand, the amount of clearance B between the top surface of the movement's basic thickness and the back cover 6 is an absolute value in the structure of a watch, as it is the sum of processing errors, deformation due to impact and external pressure, and the amount included as a margin in the design. However, even if processing errors are excluded, it ends up being larger than the amount of catching A. Now, especially in cases where the back cover 6 and the body are integrated, it is necessary to insert the winding stem 2 after inserting the movement during assembly, and to take out the movement, it is necessary to first remove the winding stem 2. At these times, the mandarin duck 3 is moved toward the upper surface of the movement by the amount A of the hook between the stepped portion of the winding stem 2 and the mandarin duck 3 to release the hook. Under this action, the back presser 4 protrudes from the top surface of the movement, but the amount of engagement A between the step part of the winding stem 2 and the mandarin duck 3 is equal to the gap amount B between the top surface of the movement basic thickness and the back cover 6 as described above. By providing substantially the same amount, the amount of protrusion toward the upper surface of the movement can be absorbed by the gap amount B, and the winding stem 2 can be attached and detached without any problem. Moreover, in this case, excessive movement is prevented by the back presser 4 coming into contact with the back cover 6, and there is no possibility that the mandrel 3 and the back presser 4 will disengage or the panel part of the back presser 4 will break. You can also get the desired effect.

Note that the above explanation can be replaced with the mandarin duck in watches where the mandarin duck has a back pressing function and no back pressing, or in watches where the mandarin duck is located on the upper surface of the movement. The present invention also extends to a winding stem that is loosely fitted into a horizontal hole of a winding stem holding member fixed to the main plate.

As described above, the present invention utilizes the amount of clearance between the case back and the movement (B in Figure 1), which is set as a completed watch, to move up and down the external operation switching mechanism parts such as the mandrel and back presser that occur when attaching and detaching the winding stem. and absorb it,
In other words, since it is processed in areas other than the thickness of the movement, in a movement of a certain thickness, the external operation switching mechanism parts can utilize all of this thickness, and the plates of these structural parts can be used. It is possible to provide an external operation switching mechanism with a sufficiently large thickness and inner thickness, and stable quality, which increases the degree of freedom in determining the position of the winding stem in the thickness direction of the movement. If the plate thickness and wall thickness of the structural parts of the winding stem could be designed to be the same as before, there would be no need to provide the cross-sectional space that occurs when the winding stem is attached and detached within the thickness of the movement, and it would be possible to easily reduce the thickness of the movement, for example.
This is particularly effective for watches with movement thicknesses of 1.5 mm to 1 mm or less.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of one embodiment of an external operation switching mechanism for a wristwatch according to the present invention, and FIG. 2 is a sectional view of the main part at a different position from that in FIG. 1... Main plate, 2... Winding stem, 3... Mandarin duck, 4
... Back presser, 6... Back cover.

Claims (1)

[Scope of utility model registration request] The upper surface of the movement and the external operation switching mechanism parts such as the mandrel and back presser are configured to face the back cover of the watch case, and the stepped part of the winding stem that loosely fits into the side hole of the main plate and the appropriate amount of engagement. An external operation switching mechanism such as the mandarin duck that engages and, when the winding stem is attached or removed, the engaging portion moves toward the upper surface of the movement to release the engagement, or the back presser that presses the mandarin mandarin against the main plate. In at least one of the parts, the uppermost surface of the engaging portion of the mandarin duck that moves toward the upper surface of the movement, the pressing portion of the back presser, etc. is substantially aligned with the upper surface of the movement;
The amount of clearance between the upper surface of the movement and the back cover of the watch case is approximately the same as the amount of engagement, and the uppermost surface of the external operation switching mechanism component that temporarily occurs when the winding stem is attached or detached. An external operation switching mechanism for a wristwatch, characterized in that the protrusion of a portion set from the upper surface of the movement is absorbed into a gap between the upper surface of the movement and the back cover of the watch case.