摘要 |
An adapter coupling device includes an adapter wrapped byan outer sleeve and biased by a large spring. The adapter has a polygonal recess in the upper portion, a circular recess under the polygonal recess for receiving a positioning block which is biased by a small spring, two pairs of the first and second radial through hole in upper and lower peripheries for engaging with two pairs of steel balls. The outer sleeve has an introrse upper portion which has an asymptotic inner wall, an annular groove in a middle inner wall and an annular flange on lower end, a screwdriver inserted into the polygonal recess of the adapter has a hexagon shank, a rhombic notch in each of the corners of the shank, when inserting the screwdriver into the adapter, the asymptotic wall of the sleeve is functioned to press the steel balls in the first radial through holes engaging within the rhombic notches of the shank so that the screwdriver is checked.
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