Patent ID: 6840143

Claim:
An adapter for screwdriver having elastic retainer ring comprising: a sleeve, a slide ring, a spring and a retainer ring, wherein the slide ring is a column member interiorly defined with a multi-stage hole, in the a front of the multi-stage hole is sequentially provided an cone inner ring having increased cone ratio, a secondary inner ring and a big inner ring a hexagonal socket hole and an annular groove are defined at the front end of the sleeve, and the annular groove is used to receive a C-shape ring, the retainer ring, the C-shape ring, the spring and a ring are mounted to a assembling diameter of the sleeve, the retainer ring is formed with a gap and an internal diameter of the retainer ring is minor than the assembling diameter of the front end of the sleeve, the retainer ring is further axially provided with a flange in connecting with a downward flange, at the outer periphery of the assembling diameter of the sleeve thereof a hole is defined for the passage of the downward flange, through which, the downward flange is able to engage in a retainer groove of the screwdriver bit; the retainer ring is further provided at both sides of the downward flange with a notch, respectively.