Large volume container with gasketless seal

Claim 1

A plastic molded container and closure assembly for holding large volume contents comprising: a container having an encircling container wall, an annular rim on an upper open end of said container wall; a one-piece closure molded of resilient flexible plastic material having a top wall for covering the open end of the container wall; an interlocking flexible bead on said closure and a rigid bead on said container for interlocking engagement with each other to secure the closure onto the container; an annular sealing bead on said rim projecting upwardly; inner and outer sealing flanges on said closure depending from the underside of said closure, said sealing flanges being spaced apart a predetermined distance to receive and to abut said sealing bead when said closure is secured onto said container; said sealing bead being tapered in an upward direction to a rounded free end, said sealing bead being centered between said sealing flanges and having a width greater than said predetermined distance for being abutted by said flanges and for spreading said flanges in a radial direction; said inner and outer sealing flanges being depending rings integral with a top rim portion of said closure and being substantially longer in their downward direction than in their cross-section thickness for easy deflection by the sealing bead and for deflection by internal or external pressure to more tightly abut a side of said sealing bead.