Container bottom structure
First Claim
1. In a container having a side wall, at least an end portion of the side wall being generally symmetrical about a central axis of the container, and a bottom structure closing the container at the side wall end portion, the outer surface of the bottom structure comprising a central concave dome portion, a convex annular rim portion circumscribing the dome portion and merging therewith and with the side wall end portion, and a plurality of radially oriented foot portions extending axially outwardly of the rim portion, each foot portion having lateral margins merging with the rim portion to form a rib portion between each pair of adjacent foot portions, the radial profile of each foot portion comprising a curve tangent to the radial profile of the dome portion and to the profile of the side wall end portion, the improvement comprising the feature that the foot portion curve comprises a plurality of tangential arcs in series, the radii of curvature of adjacent ones of the lastmentioned arcs being unequal.
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Accused Products
Abstract
An improved bottom structure for plastic bottles of the type suitable for containing carbonated beverages. The outer surface of the bottom structure is formed with a central concave dome portion and a number of radial foot portions extending axially outwardly. The radial profile of each foot portion is a curve which merges with the dome portion and with the side wall of the container and which comprises a plurality of tangential arcs in series. Also disclosed is an improved mold for forming such bottom structures.
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Citations
15 Claims
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1. In a container having a side wall, at least an end portion of the side wall being generally symmetrical about a central axis of the container, and a bottom structure closing the container at the side wall end portion, the outer surface of the bottom structure comprising a central concave dome portion, a convex annular rim portion circumscribing the dome portion and merging therewith and with the side wall end portion, and a plurality of radially oriented foot portions extending axially outwardly of the rim portion, each foot portion having lateral margins merging with the rim portion to form a rib portion between each pair of adjacent foot portions, the radial profile of each foot portion comprising a curve tangent to the radial profile of the dome portion and to the profile of the side wall end portion, the improvement comprising the feature that the foot portion curve comprises a plurality of tangential arcs in series, the radii of curvature of adjacent ones of the lastmentioned arcs being unequal.
- 2. In a container having a side wall, at least an end portion of the side wall being generally symmetrical about a central axis of the container, and a bottom structure closing the container at the side wall end portion, the outer surface of the bottom structure comprising a central concave dome portion, the radial profile of the outer surface of the dome portion comprising a first concave arc, a convex annular rim portion circumscribing the dome portion and merging therewith and with the side wall end portion, and a plurality of radially oriented foot portions extending axially outwardly of the rim portion, each foot portion having lateral margins merging with the rim portion to form a rib portion between each pair of adjacent foot portions, the radial profile of the rib portion comprising a first curve tangent to the first arc and to the profile of the side wall end portion, the radial profile of each foot portion comprising a second curve tangent to the first arc and to the profile of the side wall end portion, the improvement comprising the feature that the second curve comprises a plurality of tangential arcs in series, the radii of curvature of adjacent ones of the lastmentioned arcs being unequal.
- 4. In a container having a side wall, at least an end portion of the side wall being generally symmetrical about a central axis of the container, and a bottom structure closing the container at the side wall end portion, the outer surface of the bottom surface comprising a central concave dome portion of substantially spherical form whereby the radial profile of the outer surface thereof comprises a first concave arc having its center of curvature on the axis, a convex annular rim portion circumscribing the dome portion and merging therewith and with the side wall end portion, and a plurality of radially oriented foot portions extending axially outwardly of the rim portion, each foot portion having a radially inner end portion merging with the dome portion, a radially outer end portion merging with the side wall end portion, and lateral margins merging with the rim portion to form a rib portion between each pair of adjacent foot portions, the radial profile of the rib portion comprising a first curve tangent to the first arc and to the profile of the side wall end portion, the radial profile of each foot portion comprising a second curve tangent to the first arc and to the profile of the side wall end portion, the improvement comprising the feature that the second curve comprises a second arc tangent to the first arc, and a third convex arc tangent to the second arc and to the profile of the side wall end portion, the radii of curvature of the second and third arcs being unequal.
- 10. In a container having a side wall, at least an end portion of the side wall being generally symmetrical about a central axis of the container, and a bottom structure closing the container at the side wall end portion, the outer surface of the bottom structure comprising a central concave dome portion of substantially spherical form whereby the radial profile of the outer surface thereof comprises a first concave arc having its center of curvature on the axis, a convex annular rim portion circumscribing the dome portion and merging therewith and with the side wall end portion, and a plurality of radially oriented foot portions extending axially outwardly of the rim portion, each foot portion having a radially inner end portion merging with the dome portion, a radially outer end portion merging with the side wall end portion, and lateral margins merging with the rim portion to form a rib portion between each pair of adjacent foot portions, the radial profile of the rib portion comprising a first curve tangent to the first arc and to the profile of the side wall end portion, the radial profile of each foot portion comprising a second curve tangent to the first arc and to the profile of the side wall end portion, the improvement comprising the feature that the second curve comprises a second concave arc tangent to the first arc, a third convex arc tangent to the second arc, and a fourth convex arc tangent to the third arc and to the profile of the side wall end portion, the radii of curvature of the third and fourth arcs being unequal.
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15. In a container having a side wall and a bottom structure closing the container at an end portion of the side wall, the outer surface of the bottom structure comprising a central concave dome portion, a convex annular rim portion circumscribing the dome portion and merging therewith and with the side wall end portion, and a plurality of radially oriented foot portions extending axially outwardly of the rim portion, each foot portion having lateral margins merging with the rim portion to form a rib portion between each pair of adjacent foot portions, the radial profile of each foot portion comprising a curve tangent to the radial profile of the dome portion and to the profile of the side wall end portion, the improvement comprising the feature that the foot portion curve comprises a plurality of tangential arcs in series, adjacent ones of the arcs having separate centers of curvature.
Specification