With Crown Or Stem Details Patents (Class 368/308)
  • Patent number: 4313187
    Abstract: A water resisting crown structure for electronic wristwatches comprises a guide pipe secured to a watch case, a crown stem slidably engaged in the guide pipe, and a crown locked to the guide pipe by a thread engagement. The guide pipe has an outwardly extending large diameter portion having a thread thereon. The crown stem is connected to a correcting means such as hands and calendar correcting means of the electronic wristwatch and has a non-circular flange on an outer end portion. The crown has an inner cylindrical portion and an outer cylindrical portion which are coaxial with the guide pipe and crown stem. The inner cylindrical portion has a non-circular inner wall engaged with the non-circular flange of the crown stem. The outer cylindrical portion has an inner thread adapted to be engaged with the thread of the guide pipe for locking the crown. A packing is provided in the annular space between the outer cylindrical portion and the inner cylindrical portion of the crown.
    Type: Grant
    Filed: April 25, 1980
    Date of Patent: January 26, 1982
    Assignee: Citizen Watch Co., Ltd.
    Inventors: Masahiko Waki, Yasuo Maekawa