Patent ID: 7070164

Claim:
A coupling member of a pipe coupling comprising: a tubular body having a though hole; and a valve disposed in said through hole, wherein said valve comprises: a valve holder movable in a direction of an axis of said through hole between a closing position and an opening position; and a rotatable valve member supported by said valve holder; said valve holder comprises: a first tubular portion; a rotatable valve member support portion; and a second tubular portion, which are arranged in that order along said axis of said through hole; said first and second tubular portions have first and second axial through holes respectively; said rotatable valve member support portion supports said rotatable valve member such that said rotatable valve member is rotatable about a pivotal axis A extending normal to said axis of said through hole so that, when said valve holder is moved between said opening position and said closing position, said rotatable valve member is rotated about said pivotal axis A between an opening rotational position and a closing rotational position, respectively; said rotatable valve member has a third through hole extending normal to said pivotal axis A which is aligned with said first and second through holes when positioned at said opening rotatable position thereby allowing a fluid to flow through said coupling member; said rotatable valve member has an outer surface which is formed with an annular sealing portion adapted to be sealingly engaged with an annular portion on an outer surface of said first tubular portion which surrounds an end opening of said first through hole facing said rotatable valve member support portion when said rotatable valve member is positioned at said closing rotational position, whereby said outer surface of said rotatable valve member sealingly blocks said end opening of said first through hole to prevent a fluid from flowing through said coupling member; and said outer surface of said rotatable valve member has a portion which passes through said annular portion on said outer surface of said first tubular portion when said rotatable valve member rotates between said opening rotational position and said closing rotational position, said portion having smaller radii with relative to said pivotal axis A than said annular sealing portion so as to reduce a friction force generated between said outer surface of said rotatable valve member and said annular portion of said outer surface of said first tubular member when said rotatable valve member rotates between said opening rotational position and said closing rotational position.