Adjustable manhole cover

An adjustable manhole cover support frame comprising:

• (a) a base unit having an open ended sleeve with flange means on a bottom end portion thereof, said flange means extending laterally from said sleeve and securable with respect to an upper end portion of a vertical manhole conduit means providing an upward extension thereof;
• (b) a top manhole cover support unit adjustably supported on said base unit and having a first outer annular wall and a second inner wall, said inner and outer walls being spaced apart from one another and extending a selected distance downwardly from a top plate providing a first cavity on the underside of said top unit, said top plate having an opening therethrough surrounded by said inner wall and by a shoulder with such shoulder providing means to removably support a manhole cover, said first cavity telescopically receiving therein said annular sleeve of said base unit;
• said top unit having second cavity means adjacent and radially inwardly of said first cavity means;
• said second cavity means being open only at a bottom end thereof for screw jacks to project thereinto;
• and
• (c) screw jack means for selectively adjusting the relative telescopic position of said base unit and top unit;
• said screw jack means comprising a plurality of spaced apart rods slidably projecting through the bottom open end of said second cavity means each rod having a nut threaded thereon which acts against a bottom end of said top unit;
• each said rod having a lower end portion engaging said flange means on said base unit for support thereby.