Plastic blow molded freestanding container

• US 6,908,002 B2
• Filed: 10/20/2003
• Issued: 06/21/2005
• Est. Priority Date: 11/15/1990
• Status: Expired due to Fees

• Current Assignee: Plastipak Packaging Incorporated (Plastipak Holdings Incorporated)
• Original Assignee: Plastipak Packaging Incorporated (Plastipak Holdings Incorporated)
• Inventors: Young, William C., Darr, Richard C., Behm, Dale H.
• Primary Examiner(s): Weaver, Sue A.
• Application Number:
  US10/689,360
• Publication Number:
  US 20040079721A1
• Time in Patent Office: 610 Days
• Field of Search: 215/373, 215/375, 220/606, 220/608, 220/609, 220/6
• US Class Current: 215/375
• CPC Class Codes: B65D 1/0284 having a discontinuous contact surface, e.g. discrete feet

Abstract

A plastic blow molded container (10) is disclosed as including a freestanding base structure (20) that is constructed with a plurality of alternating hollow legs (22) and curved ribs (34), and a hub (41) from which the legs and ribs extend radially with a construction that provides good stability against tipping as well as the capability of withstanding internal pressure. The legs (22) have lower flat feet (24) with an outer diameter D_f, and the hub (41) has a periphery connected to the feet and ribs with a height H_p such that the ratio of the diameter D_f over the height H_p is in the range of about 25 to 90 to maintain strength without the hub engaging the supporting surface on which the feet rest. The construction disclosed of the legs (22), ribs (34) and hub (41, 41′ and 41″) enhances the capability of the base structure in providing good stability as well as the capability of withstanding internal pressure and stress cracking.

Claims

1. A plastic blow molded container having a central axis A and including a body portion that extends vertically about the central axis A and has a lower extremity of a round shape with a diameter D, an upper end closure unitary with an upper extremity of the body portion and including a dispensing spout, and a freestanding base structure unitary with the body portion to close the lower extremity thereof, said freestanding base structure comprising:

a plurality of downwardly projecting hollow legs spaced circumferentially from each other with respect to the body portion;

each leg having a lower flat foot coplanar with the feet of the other legs to cooperate therewith in supporting the container in an upright position;

each leg also having an outer wall that extends from the outer extremity of the flat foot thereof to the body portion;

the outer wall of each leg having a curved shape including an upper end that is tangent with the adjacent portion of the lower extremity of the body portion;

the lower flat fee of the legs having an outer diameter D_f;

the flat foot and the outer wall of each leg having a curved junction;

each leg also having an inner connecting portion that is inclined and extends upwardly and inwardly from the inner extremity of the flat foot thereof; and

each leg also having a pair of side walls that cooperate with the flat foot, the outer wall and the inner connecting portion to close the leg;

a plurality of curved ribs spaced circumferentially from each other between the downwardly projecting legs and connecting the adjacent side walls of the legs;

each rib having an outer upper end that extends upwardly for connection to the body portion of the container;

each rib also having an inner lower end located between the inner connecting portions of the legs on opposite sides thereof and extending downwardly and inwardly toward the central axis A of the container;

each rib also having a curved intermediate portion that extends between the outer upper and inner lower ends thereof with an outwardly convex shape and each rib having a radius of curvature R_r greater than about 0.6 of the diameter D of the lower extremity of the body portion and with a center of curvature on the opposite side of the central axis A from the rib; and

a generally round hub that is located along the central axis A with the legs and curved ribs extending radially therefrom;

said hub having a periphery with a diameter D_h in the range of about 0.15 to 0.25 of the diameter D of the lower extremity of the body portion;

the periphery of the hub being spaced above the plane of the flat feet of the legs by a height H_p, the ratio of the diameter D_f over the height H_p being in the range of about 25 to 90; and

the hub having connections to the upwardly extending inner connecting portions of the legs and the hub also having connections to the downwardly extending inner lower ends of the curved ribs.

2. A plastic blow molded container as in claim 1 wherein the hub of the base structure has an upwardly extending shape including a periphery connected to the upwardly extending inner connecting portions of the legs and to the downwardly extending inner lower ends of the curved ribs.

3. A plastic blow molded container as in claim 1 wherein the hub has a generally flat shape that extends horizontally and has a periphery connected to the upwardly extending inner connecting portions of the legs and to the downwardly extending inner lower ends of the curved ribs.

4. A plastic blow molded container as in claim 1 wherein the hub has a downwardly extending shape including a periphery connected to the upwardly extending inner connecting portions of the legs and to the downwardly extending inner lower ends of the curved ribs.

5. A plastic blow molded container as in claim 1 wherein the body portion has a nominal wall thickness t and wherein the planar inner extremities of the flat feet, the inner connecting portions of the legs, the inner lower ends of the curved ribs, and the hub each has a wall thickness t′

that is at least 1.7 times the nominal wall thickness t of the body portion.

6. A plastic blow molded container as in claim 1 wherein the lower flat foot of each leg has a truncated wedge shape.

7. A plastic blow molded container as in claim 1 wherein each curved rib has a generally flat cross section between its ends.

8. A plastic blow molded container as in claim 1 which includes an odd number of legs and ribs with each leg located in a diametrical opposite relationship to an associated rib.

9. A plastic blow molded container as in claim 8 which includes five legs and five ribs.