Patent ID: 7448302

Claim:
An adapter coupling device comprising: an adapter having a polygonal recess in an upper portion, a cylindrical recess under the polygonal recess communicating with each other, a pair of first radial through holes in opposing upper peripheries, a detent disposed in at least one of said first radial through holes, a pair of second radial through holes in opposing lower peripheries receiving a pair of steel balls respectively, a first spring disposed in bottom of the cylindrical recess for biasing thereon a cylindrical positioning block which has a conical lower periphery to define an upper slope and a lower slope facing to the second radial through holes and a lower cylindrical groove in bottom of the cylindrical positioning bock for receiving the first spring, and a tang on lower end of said adapter to define a shoulder around top of the tang; an outer sleeve wrapped on said adapter having an introrse portion on top in which is a asymptotic wall, an annular groove in an inner periphery engageable with the second steel balls, a plane surface and an annular flange on lower end sliding upon the tang; and a second spring wrapped on the tang and biased between the shoulder of the adapter and the flange of the outer sleeve.