Snap-on lid

A self locking closure for use with a container having a cylindrical end portion defining a radially outwardly opening annular recess having an upper edge defining a right angle shoulder, said closure comprising:

• a unitary cover including a generally circular closure wall, a generally cylindrical, continuous sidewall having an upper edge connected to said closure wall and a continuous annular lower edge, in use, said sidewall defining a cylindrical inner surface having an inner diameter slightly greater than an outer diameter of said container annular end portion to provide a sealed fit therebetween, and a radially inwardly extending ridge on an inside of said sidewall continuous for substantially 360.degree. with the inside of the sidewall between said upper and lower edges, in use, said ridge having an inner diameter less than said container annular end portion outer diameter yet greater than an outer diameter of said annular recess, so that when said closure is installed on said container at least one of said container end portion and said sidewall is temporarily deformed to permit reception of said ridge in said recess to lock said closure on said container, said ridge having an upper annular planar surface defining a shoulder locking against said recess shoulder to effectively prevent removal of the closure;
• and
• a radially outwardly opening annular recess on an outside or said sidewall axially aligned with said ridge, wherein said sidewall radially outwardly opening annular recess includes a plurality of circumferentially spaced, longitudinally extending reinforcement ribs therein.

A self locking closure for use with a container having a cylindrical end portion defining a radially outwardly opening annular recess, the closure comprising:

• a generally circular closure wall;
• a generally cylindrical, continuous sidewall having an upper edge connected to said closure wall and a continuous annular lower edge, in use, said sidewall having an inner diameter slightly greater than an outer diameter of said container end portion;
• said sidewall being formed to include a radially inwardly extending ridge and corresponding radially outwardly opening annular recess contiguous for substantially 360.degree. with the sidewall between said upper and lower edges, in use, said ridge having an inner diameter less than said container annular end portion outer diameter yet greater than an outer diameter of said annular recess, so that when said closure is installed in said container, at least one of said container end portion and said sidewall is temporarily deformed to permit reception of said ridge in said recess to lock said closure on said container;
• and
• a plurality of circumferentially spaced, longitudinally extending reinforcement ribs in said sidewall radially outwardly opening annular recess.