Curb box

Claim 1

A curb box for underground valves having a valve body including an elongated tubular stem having a lower end formed of a resilient synthetic material defining a valve receiving bell housing, said bell housing having an open lower end, end walls, side walls intermediate said end walls, and openings defined in said end walls intersecting said open lower end for receiving valve structure, the improvement comprising a projection defined upon each bell housing side wall homogeneously formed of the associated side wall material and extending toward each other into the chamber defined by the side and end walls, each projection including a valve body engaging surface, an inwardly extending apex adjacent each surface located vertically therebelow and a cam surface below said apex obliquely disposed to the vertical, said projections frictionally engaging the sides of a valve body upon the bell housing being placed upon a valve through said open lower end, the thermal spacing between opposed projection valve body engaging surfaces being less than the dimension of the valve body engaged whereby the bell housing side walls are biased transversely of the valve body by engagement of said projections with the valve body increasing the frictional engagement of said projections and the valve body, said cam surfaces engaging the valve body and biasing said projections and side walls outwardly as the bell housing is lowered upon the valve until said apexes pass over the valve body and are disposed thereunder.