JPH0142075Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to the structure of a precious metal case for a portable watch.

[Prior art]

The general structure of a conventional precious metal case for a mobile watch is explained in detail in Figure 1. 1 is glass, 2 is a body,
2a is the inner diameter of the barrel, 2b is the groove on the back cover, 2c
is the inner diameter of the bottom of the body, 3 is the dial, 4 is the movement, 5 is the middle frame, 5a is the outer diameter of the middle frame, 6 is the back cover, 6
A is a dowel with a bite, and 7 is a padskin. The movement 4 has a dial on the top, an inner frame 5 on the outer periphery, and an outer diameter 5a of the inner frame is inscribed in the inner diameter 2a of the body 2 to absorb the radial backlash of the movement 4. The dowel 6a is inserted into the groove 2b of the body 2.
By engaging with the movement 4, the movement 4 is fixed. In the case of the above structure, the design requirement is that the inner diameter 2a of the shell be the same as the outer diameter 5a of the middle frame, but when using precious metals as the material for the shell 2, the key point in design is the cross-sectional area of the shell. However, the outer shape of the shell 2 is determined by the design, and the part of the shell 2 that engages the glass 1 has a step to engage the glass 1. Because of the need to form a Since the inner diameter 2a of the shell is necessarily determined by the thickness of the bottom surface of the shell that ensures functional dimensions such as the packing contact width, there is a limit to how much material can be added. Although it is possible to greatly reduce the amount of material to be added by removing the inner wall of the shell by cutting or other means and reducing the wall thickness of the shell, the inner diameter of the shaved inner wall of the shell becomes larger than the inner diameter of the bottom of the shell. Therefore, in a structure in which the outer diameter 5a of the inner frame is inscribed in the inner diameter 2a of the shell, the outer diameter 5a is the inner diameter 2a of the bottom of the shell.
Therefore, there was a problem in that it was structurally impossible to realize an inexpensive noble metal case for a portable watch by reducing the amount of stitching.

〔the purpose〕

This invention solves these problems,
The purpose of this is to create an undercut part on the inside diameter part of the dial part of the case as a way to absorb the looseness between the case body and the middle frame that occurs when the body wall thickness is made thinner in precious metal cases for mobile watches. form,
This problem is solved by engaging the inner frame with the cut portion, and by making the body thinner and reducing the amount of stitching as a result, it is possible to provide an inexpensive structure of a precious metal case for a portable watch. be.

〔overview〕

The structure of the precious metal case for a mobile watch of the present invention is that the structure of the precious metal case for a mobile watch has an inner frame between the outer periphery of the movement and the inner periphery of the body.
A glass is arranged above the dial parting diameter part of the inner diameter part of the case, a dial is arranged on the lower surface of the dial parting diameter part, and a glass is arranged on the entire outer circumference or part of the dial parting diameter part on the back cover side. forming a oriented undercut portion, inserting a middle frame protrusion into the undercut portion, and positioning an inner circumferential side wall portion of the middle frame protrusion and an inner circumferential side wall portion of the undercut of the body in engagement with each other; It is characterized by

〔Example〕

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. 2. Reference numeral 11 is glass, 12 is a barrel, 12a is an undercut portion of the parting diameter part of the inner diameter of the barrel, 12b is a groove in the inner diameter of the barrel, and 12c is a bottom surface of the barrel. 12d is the inner peripheral side wall of the middle frame undercut, 12e is the body wall thickness,
12f is a dial part, 13 is a dial, 14 is a movement, 15 is a middle frame, 15a is an engaging protrusion,
15b is the outer diameter of the middle frame, 15c is the inner peripheral side wall of the middle frame protrusion, 16 is the back cover, 16a is a dowel with a bite, and 17 is a packing. Parting diameter part 12f in the inner diameter part of the trunk
The undercut portion 12a is designed so that the thickness of the parting diameter portion 12f of the body 12 that engages the glass 11 is ensured by the shape to receive the glass and becomes too thick, so that the undercut portion 12a does not affect the glass 11 in this portion. The engaging portion of the engaging protrusion 15a of the middle frame 15 is formed by removing the wall while leaving a wall thickness that ensures the necessary strength of the inner frame 15. The movement 14 has a dial on the upper part and an inner frame 15 on the outer periphery.
Inner peripheral side wall portion 12d of the middle frame undercut 2a
By engaging the engaging protrusion 15a of the inner frame 15 formed at a position corresponding to the inner circumferential side wall 12d of the undercut, the inner circumferential side wall portion 15c of the inner circumferential side wall 12d of the movement 14 is absorbed, thereby absorbing the radial play of the movement 14. The movement 14 is fixed by engaging the dowel 16a with the inner diameter groove 12b of the barrel 12. The inner frame outer diameter 15b is made smaller than the barrel inner diameter 12c to prevent mutual interference. The body inner diameter groove 12b has a body wall thickness of 1
It is possible to increase the thickness to the limit that can maintain the strength of 2e, specifically from 0.3 to
0.4mm is appropriate, and the body wall thickness of the conventional structure is at least 0.8mm.
mm, making it possible to reduce the thickness of the body by more than half.

〔effect〕

As described above, according to the present invention, by forming an undercut part on the entire circumference or a part of the dial parting diameter part 12f in the inner diameter part of the body, the strength is higher than that required to protect the glass in this part. The excess wall thickness of the inner frame is removed, and an engaging portion that engages with the engaging protrusion of the middle frame is formed, and the inner circumferential side wall portion of the undercut portion and the inner circumferential side wall portion of the engaging protrusion of the middle frame engage with each other. Since it is possible to engage the movement and the barrel without touching the outer diameter of the inner frame and the inner diameter of the barrel, it is possible to freely design the inner diameter of the barrel, and as a result, the barrel wall thickness can be reduced to half of the conventional one. In the following manner, the material weight can be greatly reduced, and therefore the cost of the precious metal case for a portable watch can be significantly reduced, which has the great effect of supplying inexpensive precious metal portable watches to the market.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of a conventional precious metal case for a portable watch. FIG. 2 is a sectional view showing an embodiment of the precious metal case for a portable watch of the present invention. 2, 12...Body, 2a...Body inner diameter, 12a...
Undercut part of dial parting part, 12d... Inner peripheral side wall part of undercut part, 12f... Dial parting part, 4, 14... Movement, 5, 15...
...Middle frame, 15a...Middle frame protrusion, 15c...Inner peripheral side wall portion of the middle frame protrusion.

Claims (1)

[Scope of utility model registration request] In the structure of a precious metal case for a portable watch in which an inner frame is arranged between the outer periphery of the movement and the inner periphery of the body, a glass is arranged above the dial parting diameter part of the inner diameter part of the body, and the dial parting diameter A dial plate is arranged on the lower surface of the dial, an undercut part directed toward the back cover is formed on the entire outer circumference or a part of the outer circumference of the dial part, and a middle frame protrusion is inserted into the undercut part. A structure of a precious metal case for a portable watch, characterized in that an inner circumferential side wall of the middle frame protrusion and an inner circumferential side wall of the undercut of the body are engaged and positioned.