Citizen Watch Company, Ltd.

Kouji Fujii

Junji Satoh

Hitoshi Uchida

Ryo Fujita

Takeo Komiyama

Norio Hashimoto

Nobuto Fukushima

Toshiaki Hara

A wristwatch case () and a method of manufacturing the case, the wristwatch case comprising a wristwatch case body () made of titanium or stainless steel and a crown pipe () fixed to each other, wherein a stem hole () corresponding to the crown pipe () is formed in the wristwatch case body (), a small diameter part is formed in the crown pipe (), and a small diameter part corresponding to the a small diameter part of the crown pipe is formed in the stem hole (), the method comprising the step of fitting the crown pipe () into the stem hole () in the wristwatch case body () to form a solid phase diffusion joining part at a portion where the small diameter parts thereof are fitted closely to each other, and to form a brazed connection part at a portion other than that where the small diameter parts are fitted closely to each other, whereby a watch external part having excellent corrosion resistance and waterproof and a large number of design variations can be provided.

Timepiece external part and method of manufacturing the part

One wristwatch case, wherein a pipe is fixedly connected thereto and a connection interface between the wristwatch case and the pipe is not present substantially; the method of fixing the wristwatch, comprising the steps of providing a through-hole in the wristwatch case, press fitting the pipe of 0 mm or larger in press fitting tolerance (pipe outer diameter&#x2014;through-hole diameter) between the through-hole and the pipe, and heating the wristwatch case after the press fitting step; the other wristwatch case, wherein a pipe is fixedly connected thereto through a diffusion layer; the method of fixing the pipe of the wristwatch case, comprising the steps of forming a through-hole in the wristwatch case, press fitting the pipe of 0 mm or larger in press fitting tolerance (outer diameter of pipe having a metal film formed on the surface thereof&#x2014;diameter of through-hole) between the through-hole and the pipe having a metal film formed on the surface thereof, and heating the wristwatch case in vacuum or reducing gas atmosphere after the press fitting step.

Wristwatch case and method of fixing pipe to wristwatch case

An adjust pin ( ) for connecting a plurality of blocks ( ) to each other to make up a wrist watch band ( ) is formed of a metal with a property having a superelastic region where a stress remains constant against variation in strain. The adjust pin ( ) is provided with a bent part ( ) for causing a bending stress in the superelastic region to act on the inner wall face of a connecting through-hole ( ) of a block ( ) in a state wherein the block ( ) is joined with an adjoining block ( ). When the adjust pin ( ) is inserted in the blocks ( ), and the bent part ( ) is positioned in the connecting through-hole ( ), the bent part ( ) provides a force acting on the inner wall of the connecting through-hole ( ) by the agency of the bending stress in the superelastic region, thereby securely holding the adjust pin ( ) by a spring force thereof.

Wrist watch band adjust pin, method of manufacturing the pin, and wrist watch band connection structure

Growing community of inventors

Tokorozawa, Japan

Kouji Fujii