Watch and crown used in this watch

A crown for a watch, comprising:

• a crown shaft;
• and
• a crown ring having an internal thread in its inner surface for threaded connection to a stem pipe of a watch;
• said crown shaft having a barrel insertion cylindrical portion of a diameter smaller than that of said crown ring and a ring connection portion integral with said barrel insertion cylindrical portion and threadedly connected to the internal thread of said crown ring.

A watch comprising:

• a watch case having a pipe installation hole extending therethrough;
• a stem pipe having an insertion portion inserted into the pipe installation hole and fixed to the watch case and a protruding portion connected to the insertion portion and protruding outside the watch case, the protruding portion having an external thread;
• and
• a crown comprised of a crown shaft and a crown ring, the crown shaft being axially displaceable and rotatable in the insertion portion of the stem pipe and having an inner end portion slidably attached to a watch stem and an outer end portion disposed outside the watch case, and the crown ring being disposed circumferentially around and threadedly connected to the outer end portion of the crown shaft and having an internal thread threadedly engageable with the external thread of the stem pipe protruding portion in response to rotation of the crown ring in one direction to axially displace the crown ring inwardly into abutment with the watch case thereby locking the crown against inadvertent rotation and disengageable from the external thread in response to rotation of the crown ring in the opposite direction to permit the crown to be pulled outwardly and rotated to change a function of the watch.