Patent ID: 7431587

Claim:
An adaptor assembly for coupling a dental handpiece to an elongated dental extension member, said handpiece having a head portion, said head portion including a socket having a hollow bore in fluid communication with a fluid source, said assembly comprising: a coupling member having an inwardly extending portion threadably engageable with a mating threaded portion of said socket, said coupling member further comprising a cylindrical housing having a coaxially spaced throughbore for receiving said extension member, said coupling member further including an annular reentrant cavity capable of surrounding said extension member; annular resilient sealing means received by said reentrant cavity within said housing, said sealing means capable of being in frictional contact with said extension member; a collar secured to said housing, said collar having an internally located channel; annular retention means for slidably and sealingly retaining said extension member within said throughbore, said retention means supported within said channel of said collar, said retention means comprises a flexible annular disc, said disc frictionally retaining said extension member in said throughbore; and a plunger having an annular opening capable of surrounding said extension member and arranged for inward movement with respect to said head portion and in contact with said retention means for axial movement of said retention means for temporary release of said retention means.