Plastic bucket defining annular inwardly projecting ridge

A plastic bucket having a lip at its mouth, a plastic bucket lid in sealingly secured relation to the lip of said bucket, the improvement comprising, in combination:

• the interior wall of said bucket defining an annular, inwardly-projecting ridge positioned adjacent to but spaced from said lip, said ridge extending around the inner circumference of said bucket and defining an annular, inwardly-pointed apex, said lid defining first and second transversely extending annular walls forming an annular open depression, said second annular wall defining the outer limit of said depression, said first annular wall defining the inner limit of said depression and constituting an integral segment of the bucket lid, being connected at opposed sides to other portion of the bucket lid, and a third transversely-extending annular wall positioned outwardly from said second annular wall, said second and third annular walls, in turn, defining between them an annular locking slot which receives and holds the lip of said bucket, said second wall also carrying an outwardly-positioned annular projection defining a surface which faces the annular locking slot and which defines an angle to the plane of said second annular wall, said annular projection being in contacting and retaining relation with a mating projection of said bucket lip positioned within the locking slot, the second wall also defining, below said outwardly-positioned annular projection, a surface which is of a shape complimentary to the shape of the side of said annular ridge which faces the mouth of said bucket, to form an annular, abutting sealing surface between said outer side of the ridge and the second wall and extending essentially to said apex, said third annular wall defining an inwardly-positioned projection adapted to interlock with an outwardly facing projection of said bucket lip, positioned within the locking slot, said first annular wall being adapted for preferentially flexing upon shock adjacent the bucket lip, causing said second wall to remain relatively immovable under such circumstances for improved sealing strength.