Safety closure for open head containers

A closure assembly of the type having a container with a removable lid, said container having a sidewall and being substantially cylindrical and open at its top portion, said container having a chime carried by said wall and circumscribing said top portion, said chime protruding radially outwardly of the wall of said container and having a shoulder along its bottom portion, wherein the improvement comprises a removable plastic cap assembly for closing said open top, said cap assembly including:

• (a) a removable plastic cap having (i) a central web for extending over said open top portion of said container when said cap is placed on said container, said web having a substantially circular periphery, (ii) a sealing ring fixed to said periphery of said web, said sealing ring being downwardly opening and having an annular top portion for extending over the rim of said chime when said cap closes the top portion of said container, and (iii) a plurality of lugs carried by the outer portion of said top portion, said lugs being circumferentially spaced around the periphery of said top portion of said cap for extending around said chime, each of said lugs having an inwardly protruding flange for protruding beneath a portion of said chime when said cap closes said container and said lug is moved inwardly toward said container, said lugs normally extending downwardly and outwardly from said top portion of said cap;
• and
• (b) locking ring for extending over said top portion of said sealing ring, said locking ring opening downwardly and having an inwardly extending lip for engaging beneath a portion of said sealing ring when said sealing ring is disposed beneath a portion of said locking ring, said lugs having portions which protrude downwardly between said lip of said locking ring and said wall of said container and terminating below said locking ring.