Locking cover assembly for preventing unauthorized access to a utility shut off valve

A cover assembly in combination with an open topped curb box, said cover assembly including a cover member normally completely covering said open topped curb box for preventing access to a utility shut off valve located below said curb box and only accessible through said open top of said curb box when said cover member is removed from said curb box open top;

• a clamping plate also included in said cover assembly mounted to be rotated with said cover member and held in a position beneath and parallel to said cover member;
• said cover assembly also including a security screw extending through a hole in said cover member and rotatable therein projecting axially down from an underside of said cover member, a lower end of said security screw threaded into a threaded hole in said clamping plate;
• said curb box provided with an integral flange radially projecting inwardly from an outer wall of said curb box into an inner space defined within said curb box outer wall;
• said clamping plate rotatable in said box with said cover member and within said curb box inner space and formed with a cutout extending in from an outer perimeter thereof of a shape matching said flange shape so as to enable said clamping plate to be moved axially past said flange to be disposed within said curb box below said flange after said cover assembly including said cover member and said clamping plate is rotated to align said cutout with said flange, rotation of said cover assembly in one direction after said clamping plate is disposed below said flange causing a portion of said clamping plate to be positioned beneath said flange;
• rotation thereafter of said security screw in one direction causing said clamping plate to thereafter be drawn upwardly into engagement with an underside of said flange to create an engagement between said cover member and said curb box;
• and, when said security screw is rotated in an opposite direction causing lowering of said clamping plate is produced to be disengaged from said underside of said flange to enable rotation of said cover assembly in said curb box back to said aligned position of said clamping plate cutout and said flange thereby allowing lifting of said cover assembly out through said curb box open top.