Plastic container with fluted inner wall

{
  "publication_number": "US9533789B2",
  "country": "US",
  "kind": "B2",
  "title": "Plastic container with fluted inner wall",
  "abstract": "A molded plastic container having an open top and an outwardly smooth sidewall wherein the interior surface of the sidewall is characterized by a plurality of parallel vertical flutes defined by shallow, smooth concavities joined by flat columns of uniform thickness wherein the ratio of the circumferential diameter of each concavity to the circumferential width of a column is about 8:1. The outside surface of the container is smooth and molded with two integral, vertically spaced, circumferential rings for added hoop strength. The container exhibits a high stacking strength-to-weight ratio. The preferred material is HDPE.",
  "claims": [
    "1. An open-top injection molded plastic container comprising: a continuous circular sidewall having inside and outside surfaces; a bottom integral with said sidewall; wherein the sidewall has formed on the inside surface thereof a plurality of circumferentially spaced concave vertical flutes having vertical edges of a first maximum wall thickness; said concave flutes having centers of a second minimum wall thickness substantially less than said maximum thickness wherein between the flutes are vertical, essentially flat-surfaced columns of a constant thickness equal to said maximum wall thickness and wherein the columns and flutes extend vertically for more than 50% of the height of the sidewall; the outside surface is smooth and unfluted; and wherein the center depth of the concavity is about 0.022 inches and the thickness of the sidewall is about 0.070 inches at the center of a concavity and about 0.092 inches at the center of a flat-surfaced column.",
    "2. A molded plastic container as defined in claim 1 wherein the ratio of the circumferential width of each concavity to the circumferential width of a flat-surfaced column is between 5:1 to 10:1.",
    "3. A molded plastic container as defined in claim 1 wherein the capacity of the container is at least 5 gallons.",
    "4. A molded plastic container as defined in claim 1 wherein outside surface of the sidewall has integrally molded therewith at least one circumferential ring which is closer to the top than to the bottom.",
    "5. A molded plastic container as defined in claim 1 wherein the outside surface of the sidewall has integrally molded therein a pair of circumferential rings, at least one of said rings being intercepted by a pair of diametrically opposite bail ears.",
    "6. A molded plastic container as defined in claim 1 wherein the flutes taper at the tops and blend into an internally smooth annular seal band proximate the open top of the container and of uniform thickness around the circumference thereof.",
    "7. A molded plastic container as defined in claim 6 wherein the flutes have flat bottoms proximate the bottom of the container.",
    "8. A molded plastic container as defined in claim 1 wherein the material of construction is HDPE.",
    "9. A five-gallon molded plastic container comprising: a continuous circular sidewall having a smooth cylindrical outer surface and a vertically fluted inner surface formed by between twenty-five and thirty-two shallow, concave vertical flutes interspersed with flat-surfaced vertical columns of about ⅛ to ¼ inch in width and wherein the columns are of uniform wall thickness in the range of about of about 0.090 to 0.092 inches and the flutes have a minimum wall thickness of about 0.070 inches and wherein the columns flare outwardly into a circumferential seal band proximate the top of the sidewall and having a uniform wall thickness of the same thickness as the columns."
  ],
  "description_excerpt": "The disclosed device lies is the field of molded plastic containers typically used to ship and store bulk products.\n\nMolded plastic containers are used to ship and store a wide variety of bulk products such as food, wallpaper paste and driveway sealant as examples. Such containers must withstand rough handling, a wide temperature range and stacking while filled. For 5 and 6 gallon containers, the required stacking tolerance may be as high as 3000 lbs. The preferred material for the containers is high-density polyethylene (HDPE) and the preferred configuration is tapered to allow nesting of empty containers.\n\nDisclosed herein is an improved plastic container for shipping and storing various goods which meets the requirements set forth above while at the same time reducing weight by reducing the amount of plastic material used in the fabrication of the container. In general, this is achieved by injection molding the container such that the sidewall exhibits a smooth, cylindrical outer surface and a vertically fluted interior surface wherein the flutes are characterized by regularly spaced, smooth concavities interspersed with columns of full wall thickness. In a preferred embodiment, the flutes taper at the top so that the columns flare outwardly and join one another in a seal area. The ratio of the width of a concavity or flute at the widest point to the width of a column at the narrowest point is on the order of 8:1. The concavities lighten the container by eliminating material while the columns provide the necessary stacking strength.",
  "cpc": [
    "B65D 1/42",
    "B65D 1/165"
  ],
  "ipc": [
    "B65D 1/12",
    "B65D 1/44",
    "B65D 1/16",
    "B65D 1/42"
  ],
  "assignees": [
    "Letica Corp"
  ],
  "inventors": [
    "John R. Selina",
    "Christopher Myles LARSEN"
  ],
  "filing_date": "2014-01-23",
  "publication_date": "2017-01-03",
  "grant_date": "2017-01-03",
  "priority_date": "2014-01-23",
  "application_number": "US-201414162033-A",
  "family_id": "53544140",
  "cited_by_count": 22,
  "citations": [
    "US3070275A",
    "US3169688A",
    "US3194468A",
    "US3169689A",
    "USD295480S",
    "US5261558A",
    "US5279442A",
    "US5305911A",
    "US5322213A",
    "US5310073A",
    "USD380647S",
    "US6550645B2",
    "US8495854B2",
    "US7216769B2",
    "US8210391B2",
    "US20100108556A1",
    "US20100264202A1",
    "US8348086B2",
    "US20120018429A1",
    "US8684223B1",
    "US20130075356A1"
  ]
}