Package having means for providing coaxial alignment in a stack thereof

A package comprising a container and a closure therefor;

• said container having a circumferentially continuous sidewall and a bottom member, said bottom member being situated within the space defined by said sidewall adjacent the lower end of said sidewall, the upper portion of said sidewall curling outwardly and downwardly to form a rolled top rim, the lower portion of said sidewall curving inwardly to form a generally convexly curved bottom rim;
• said closure comprising a first wall, a circumferentially continuous generally concavely curved second wall extending upwardly and outwardly from the upper extent of said first wall, a circumferentially continuous rim wall extending outwardly from the upper extent of said second wall, a circumferentially continuous skirt wall extending generally downwardly from the outer extent of said rim wall, and a diaphragm connected to the lower extent of said first wall;
• said first wall at least generally conforming to the contour of the portion of said sidewall adjacent to and below the commencement of said rolled top rim;
• the maximum outside diameter of said first wall before the application of said closure onto its respective container being at least as great as the minimum corresponding dimension of the inside surface of the portion of said sidewall contacted by said first wall upon the application of the closure onto the respective container, thereby providing a frictional engagement of the closure and the respective container;
• the configuration of said second wall at least generally conforming to at least an outer portion of said curved bottom rim to provide a positioning means for engaging the corresponding portion of the curved bottom rim of an at least substantially identical container superimposed thereabove as said curved bottom rim of said superimposed container enters the space defined by said second wall, thereby causing said superimposed container to be positioned on said second wall coaxially with said closure;
• said first wall being interrupted by a plurality of spaced apart support lugs which project inwardly from said first wall toward the central vertical axis of said closure, the upper surface of each of said plurality of support lugs extending inwardly from the lower extent of said second wall to serve as additional support surface for the curved bottom of said superimposed container.