Patent ID: 7744305

Claim:
A manhole with a locking device comprising: a manhole frame including an annular retaining step formed on an inner circumferential surface thereof, the annular retaining step having a plurality of insertion slots protruded inwardly from an inner circumference of the retaining step and a latching protrusion formed in such a manner that a top surface of the insertion slots is partially opened, and a plurality of indentations formed on an upper end of the inner circumferential surface of the manhole frame; a bearing member including a female screw portion centrally formed therein and a plurality of fastening pieces radially formed outwardly from the outer circumferential edge thereof so as to be detachably fastened to the plurality of insertion slots; a manhole cover rested on the retaining step of the manhole frame and including a plurality of protrusions outwardly protruded from the outer circumferential surface of the manhole cover so as to correspond to the plurality of indentations; and a packing member interposed between the manhole frame and the manhole cover,wherein the manhole cover has a through-hole centrally formed therein, so that an upper portion of a vertical screw rod is rotatably inserted into the through-hole, the vertical screw rod having a male screw portion formed on the lower portion thereof so as to be threadably fastened to the female screw portion of the bearing member, a head portion formed on the upper portion thereof so as to abut against an upside surface of the manhole cover, and a support portion formed on the upper portion so as to abut against an underside surface of the manhole cover, whereby the head portion of the vertical screw rod is rotatable so that the manhole cover is lowerable to be closed to thereby maintain watertightness, or is raisable to be opened.