Patent ID: 7192184

Claim:
A portable timepiece comprising: a case having a case band; a timepiece movement mounted in the case; a pipe connected to and extending to an exterior of the case band, the pipe having a male screw section; a winding stem extending into the case for transmitting a rotational force to the timepiece movement; and a crown having a crown shaft connected to rotate the winding stem in response to rotation of the crown shaft, a crown head having a female screw section threadedly engageable with the male screw section of the pipe and mounted for undergoing rotation to rotate the crown shaft in a state in which the male and female screw sections are disengaged from one another, and a clutch for coupling together the crown shaft and the crown head to prevent rotation of the crown shaft in a state in which the male and female screw sections are threadedly engaged with one another and for coupling the crown shaft and the crown head to allow the crown shaft to rotate in response to rotation of the crown head in a state in which the male and female screw sections are disengaged from one another, the clutch comprising first and second driven sections provided on the crown shaft and disposed parallel to each other in an axial direction of the crown shaft, and a driving section having a fitting hole formed in the crown head for selective engagement with the first and the second driven sections during movement of the crown head in the axial direction, the crown shaft having a receiving section disposed on an outer periphery thereof at a position closer to an exterior surface of the case band than the clutch so that an end of the female screw section of the crown head comes into contact with the receiving section of the crown shaft following movement of the crown head in the axial direction thereof in a state in which the male screw section of the pipe is disengaged from the female screw section of the crown head, and the receiving section and the driving section being arranged so as to be opposed to each other in the axial direction of the crown head; and an elastic body disposed between the receiving section and the driving section for biasing the crown head in a direction away from the exterior surface of the case band.