Plastic bottle and cap construction

{
  "publication_number": "US3809276A",
  "country": "US",
  "kind": "A",
  "title": "Plastic bottle and cap construction",
  "abstract": "The invention contemplates a bottle and closure-cap construction wherein locking formations hold the parts to secure a liquid-seal closure of the bottle. The nature of the liquid-seal engagement is one of circular line contact, involving a cylinder within a conical concavity, specifically between a relatively thin-walled outwardly flaring upper end of the bottle opening and the lower limit of a cylindrical seal projection on the closure wall of the cap. An axially compliant generally radially extending annular portion connects the lower end of the flared neck part to the rest of the neck and is axially stressed to resiliently load the seal engagement.",
  "claims": [
    "1. In combination, a bottle of yieldable plastic material and having an opening at a neck, and a closure cap for selectively closing the opening, interengageable locking means on said cap and neck for selectively securing the closed condition, said neck being of substantially uniform thickness and comprising a lower generally cylindrical locking portion, an upper outwardly flaring generally conical sealing portion, and an annular generally radially inwardly projecting portion connecting said cylindrical and conical portions, the radial extent of said annular portion exceeding the thickness of said portions, whereby said annular generally radial portion provides an axially compliant connection of said upper and lower portions; said closure cap including a relatively rigid outer annular wall having a bore with locking formations engageable with those of said cylindrical locking portion, said cap further having an integral axially yieldable generally radially extending annular closure-wall portion, an integral internal cylindrical seal projection radially inwardly spaced from said bore and extending axially downward for engagement with said conical portion, whereby said closure-wall portion provides an axially compliant connection of said rigid annular wall to said internal seal projection; the maximum diameter of said seal projection being greater than the minimum diameter of said inwardly projecting neck portion and at least no greater than the maximum diameter of said upper conical portion, whereby an essentially circular line-contact circumferential interference will occur for cap-to-neck assembly; and the lower limit of the cylindrical portion of said cylindrical projection being so positioned with respect to the axial relation of parts in locked condition that both said axially compliant connections are oppositely axially stressed to axially preload said interference when said cap and neck are in locked condition.",
    "2. The combination of claim 1, in which the downwardly projecting end of said seal projection has a convergent inwardly tapered region adjacent said lower limit, the angle of convergence of said tapered region exceeding the angle of outward flare of said seal portion.",
    "3. The combination of claim 2, in which the angle of outward flare of said seal portion is in the range of 15* to 25*.",
    "4. The combination of claim 2, in which the angle of outward flare of said seal portion is substantially 20*.",
    "5. The combination of claim 1, which the upper end of said neck integrally includes a short cylindrical portion.",
    "6. The combination of claim 1, in which said interengageable locking means is of the bayonet variety.",
    "7. The combination of claim 1, in which said annular radially extending portion of said neck is upwardly dished.",
    "8. The combination of claim 1, in which said annular radially extending portion of said cap is downwardly dished."
  ],
  "cpc": [
    "B65D 41/065"
  ],
  "assignees": [
    "EYELET SPECIALTY CO"
  ],
  "filing_date": "1972-09-27",
  "publication_date": "1974-05-07",
  "grant_date": "1974-05-07",
  "priority_date": "1972-09-27",
  "application_number": "US-29265072-A",
  "family_id": "23125587",
  "citations": [
    "FR434518A",
    "US3405832A",
    "US3435975A",
    "US3592349A",
    "US3613928A",
    "US3667636A",
    "US3669295A",
    "US754977A"
  ]
}