Plastic drum with reinforced sidewall

• US 6,497,338 B1
• Filed: 08/15/2000
• Issued: 12/24/2002
• Est. Priority Date: 08/15/2000
• Status: Active Grant

• Current Assignee: Stolzman, Michael D.
• Original Assignee: Stolzman, Michael D.
• Inventors: Stolzman, Michael D.
• Primary Examiner(s): Garbe, Stephen P.
• Assistant Examiner(s): Merek, Joseph C.
• Application Number:
  US09/639,036
• Time in Patent Office: 861 Days
• Field of Search: 220/62.18, 220/652, 220/628, 220/650, 220/633, 220/635, 220/FOR.181, 220/605, 220/606, 220/608, 229/400, 229/403, 229/404, 206/519, 206/520
• US Class Current: 220/628
• CPC Class Codes: B65D 1/16 of curved cross-section, e.g. cylindrical
• CPC Class Codes: B65D 1/42 Reinforcing or strengthening parts or members
• CPC Class Codes: B65D 21/0233 Nestable containers

Abstract

A unitary plastic open head drum includes a first cylindrical sidewall closed at a bottom end with a bottom wall and open at an upper end. A second generally cylindrical sidewall is concentric to and extending at least partially the length of the first sidewall, providing sufficient stiffness to resist “elephant footing” of a bottom drum in a stack of drums.

Claims

1. A unitary molded plastic drum comprising:

a generally cylindrical sidewall connected to a bottom wall to define an interior space, the cylindrical sidewall having an upper section, a middle section and a lower section, the upper section and middle section having a uniform wall thickness, the lower section including an outer sidewall and an inner sidewall and a plurality of radially extending ribs sandwiched between and connecting the outer sidewall and the inner sidewall and an annular lip connecting a top of the inner sidewall with a top of the outer sidewall and forming an interior ledge within the interior space and said outer wall tapering from a thicker portion adjacent said lip to a thinner portion adjacent said bottom.

2. The drum of claim 1 wherein the middle section is inwardly inclined.

3. The drum of claim 2 wherein a diameter of the middle section is less than a diameter of the upper section, forming a conical ledge on an inner surface of said sidewall.

4. The drum of claim 3 wherein a diameter of the lower section is less than a diameter of the middle section.

5. The drum of claim 1 wherein the lower section outer sidewall has a thickness which increases downwardly from the lip to a bottom edge.

6. The drum of claim 5 wherein the lower section inner sidewall has a uniform thickness.

7. A unitary molded plastic drum comprising:

a first generally cylindrical sidewall connected at a bottom edge to a bottom wall to define an interior space, and having an upper section, a middle section and a lower section, separated by upper and lower ledges; and

a second generally cylindrical sidewall extending downwardly from the lower ledge concentric with the first generally cylindrical sidewall lower section to define a downwardly opening space therebetween; and

a plurality of circumferentially spaced support ribs connected between said first sidewall and said second sidewall in said downwardly opening space and said outer wall tapering from a thicker portion adjacent said lip to a thinner portion adjacent said bottom.

8. The drum of claim 7 wherein the middle section is inwardly inclined.

9. The drum of claim 8 wherein a diameter of the middle section is less than a diameter of the upper section, forming a conical upper ledge on an inner surface of said first sidewall.

10. The drum of claim 9 wherein a diameter of the lower section is less than a diameter of the middle section.

11. The drum of claim 7 wherein the lower section outer sidewall has a thickness which increases downwardly from the lip to a bottom edge.

12. The drum of claim 11 wherein the first sidewall lower section has a uniform thickness.