Reservoir cap having a sealing member

摘要

The present invention is directed to a cap assembly for screwing into an opening of a reservoir for storing a fluid therein. Around the cap, formed is a sealing groove in which a sealing member is disposed. The sealing member has a sealing portion which extends toward the inner periphery of the opening, and a pair of contacting portions which extend axially toward each inner side of the sealing groove in spaced relationship with each inner side of the sealing groove by a predetermined clearance respectively. The sealing member is formed around the periphery thereof with grooves for allowing the sealing portion and contacting portions to be deflected in response to a sliding motion of the sealing member when the cap assembly is screwed into the opening.