Bottom structure for plastic containers

Claim 2

A blow molded pressure resistant plastic container having a body comprising a generally cylindrical side wall and a bottom structure, said bottom structure comprising: a central dome portion terminating in a circular bottom edge; a semi-torus shaped rim portion circumscribing said central portion and convexed downwardly from said container and having an outer marginal edge portion merging into said side wall and having an inner marginal edge portion merging with said dome portion at said circular edge; and a plurality of shallow ribs formed in said rim portion of transverse arcuate contour and intervening radially extending leg portions, each rib portion having a relatively thick ridge section and having side sections progressively thinned outwardly and merging into respective leg portions.

Claim 3

The invention according to claim 1 and said dome portion disposed for loading in compression and said ribs disposed for loading in bend.

Claim 4

The invention according to claim 2 and said ribs having maximum width in the area of juncture of the rim to the side wall and narrowing and shallowing at their outer and inner extremities.

Claim 5

The invention according to claim 3 and said by portions having narrow inner sections and broadening from said inner sections to relatively wide outer sections in the area of juncture with the side wall.

Claim 6

The invention according to claim 1 and said bottom structure having a diametric seam centered on diametrically disposed ribs.

Claim 7

In a plastic container formed of material adapted to deform when subjected to predetermined pressure loads, said container having a cylindrical lower side wall portion, an integral bottom defined by a wall comprising an inwardly convexed sperical center portion, a reversely convexed rim portion extending between said inwardly convexed center portion and said side wall and projective axially of the container below the lowermost edge of said center portion, and a plurality of reinforcing elements formed as an integral part of said rim portion and extending radially of the container and having inner ends merging into said center portion and flaring therefrom outwardly and beyond the juncture of the bottom wall with the side wall narrowing circumferentially of the container and flaring into said side wall, and said reinforcing elements defining a plurality of legs oriented radially of the container and having wide circumferential sections adjacent to said side wall and narrow inner end sections at said center portion, and said reinforcing elements having lateral side segments of relatively thin cross section in their regions of merger with respective legs and forming the sides thereof and progressively being thicker axially inwardly of the container and merging into a relatively thick arcuate inner crest portion.

Claim 8

In a plastic container formed of material adapted to deform when subjected to predetermined pressure loads, said container having a cylindrical lower side wall portion, an integral bottom defined by a wall comprising an inwardly convexed sperical center portion, a reversely convexed rim portion extending between said inwardly convexed center portion and said side wall and projective axially of the container below the lowermost edge of said center portion, and a plurality of reinforcing elements formed as an integral part of said rim portion and extending radially of the container and having inner ends merging into said center portion and flaring therefrom outwardly and beyond the juncture of the bottom wall with the side wall narrowing circumferentially of the container and flaring into said side wall, and said reinforcing elements defining a plurality of legs oriented radially of the container and having wide circumferential sections adjacent to said side wall and narrow inner end sections at said center portion, and said reinforcing elements having lateral side segments of relatively thin cross section in their regions of merger with respective legs and forming the sides thereof and progressively being thicker axially inwardly of the container and merging into a relatively thick arcuate inner crest portion.

Claim 9

The invention according to claim 6 and said elements blending at their ends into the side wall portion and said spherical portion respectively.

Claim 10

The invention according to claim 7 and said legs being essentially U-shaped in radial cross-section.