Citizen Watch Company, Ltd.

Seiji Umezawa

Tsuneji Takasugi

Hiroshi Koide

Takao Kasai

Masahiko Waki

A structure of a watch case, which comprises a watchglass, a case band member composed of a cemented carbide alloy and having a flange formed at an upper portion thereof and an annular surface formed at a lower portion of the flange, a watchglass supporting ring brazed to the case band member and having an upper surface for supporting a bottom surface of the watchglass, a packing for providing a waterproof and a back cover secured to the case band member. The packing is provided between the outer periphery of the watchglass and an annular groove. The annular groove is formed by the flange and annular surface of the case band member and the upper surface of the watchglass supporting ring.

Structure for a watch case made of cemented carbide

A joint structure of a watch body and a bezel comprising a watch body with a joint surface, a bezel with a joint surface, at least one projection extending from one of the joint surfaces welded onto the other surface, a space between said surfaces and connecting material filling said space. By thus constructing, the watch body and bezel have a durable water and air tight joint.

Joint structure of bezel and watch body

A method for fabricating a watch case comprising the steps of placing contact points of a bezel and a watch body to face to each other, applying pressure to said contact points through electrodes, and applying pulse current to said electrodes until said contact points get molten. The pulse current will allow the bezel and the body except the contact points to cool down during its intervals. Therefore, this method does not require a water-cooling system as required by conventional methods.

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Tanashi, Japan

Seiji Umezawa