Patent ID: 8333502

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; an exhaust button having a shaft portion and a button portion, the shaft portion having a detachment preventing portion configured to be caught by an edge portion of the button mounting hole from within the timepiece exterior assembly and being movably inserted into the button mounting hole, and the button portion being connected to the shaft portion and configured to be pushed inward from the exterior of the timepiece exterior assembly; an urging member provided between the button portion of the exhaust button and the timepiece exterior assembly for urging the exhaust button toward the exterior of the timepiece exterior assembly; and a plurality of seal members mounted to the shaft portion of the exhaust button in correspondence with the plurality of seal surfaces of the button mounting hole, the plurality of seal members being configured to undergo movement between a sealing position in which the plurality of seal members are held in contact with the respective seal surfaces with interference through axial reciprocation of the exhaust button and an exhaust position in which the plurality of seal members are opposed to the respective escape portions, the plurality of seal members defining in the sealing position thereof a closed space formed by the outer periphery of the shaft portion together with the escape portions opposed to the outer periphery of the shaft portion.