Patent ID: 8333503

Claim:
A portable timepiece comprising: a timepiece exterior assembly having a button mounting hole establishing communication between an interior and an exterior of the timepiece exterior assembly, the button mounting hole having a plurality of seal surfaces and a plurality of escape portions; a valve member having a valve member shaft portion and a valve member head portion, the valve member shaft portion having a detachment preventing portion configured to be caught by an edge portion of the valve member mounting hole from the exterior of the timepiece exterior assembly and being movably inserted into the valve member mounting hole so that the valve member can move toward the exterior of the timepiece exterior assembly by an inner pressure of the timepiece exterior assembly, and the valve member head portion being arranged inside the timepiece exterior assembly while being connected to the valve member shaft portion; an urging member provided between the valve member head portion and the timepiece exterior assembly for urging the valve member toward the interior of the timepiece exterior assembly; and a plurality of seal members mounted to the valve member shaft portion in correspondence with the plurality of seal surfaces, the plurality of seal members being configured to be moved between a sealing position in which the plurality of seal members are held in contact with the seal surfaces while exhibiting interference and an exhaust position opposed to the escape portions through axial reciprocating movement of the valve member, the plurality of seal members defining in the sealing position thereof a closed space together with an outer periphery of the valve member shaft portion and the escape portions opposed to the outer periphery of the valve member shaft portion.