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US4520939A Expired / Lapsed US ⏱️ 0.0 years remaining

Pilfer-proof plastic closure for containers

Assignee: Nippon Closures Co Ltd
•
Filing: 1984-02-21
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Granted: 1985-06-04
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Expires: 2004-02-21
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Abstract

Abstract A pilfer-proof plastic closure comprising a top panel wall and a cylindrical skirt wall extending downwardly from the peripheral edge of the top panel wall. The skirt wall has formed therein a circumferentially extending breakable line dividing the skirt wall into a main portion above the breakable line and a pilfer-proof bottom portion below it. The main portion has formed on its inner surface an internal thread and the pilfer-proof bottom portion has formed on its inner surface a plurality of radially inwardly projecting engaging flaps at circumferentially spaced positions. Each of said engaging flaps has a first portion extending from the inner surface of the pilfer-proof bottom portion tiltedly in a direction opposite to the direction of rotation of the closure at the time of mounting it on the mouth-neck portion of a container and a second portion bent with respect to the first portion and further extending from the end of the first portion. The first portion forms an angle α smaller than 90 degrees and the second portion forms an angle β larger than the angle α, both with respect to the tangent of the inner surface of the pilfer-proof bottom portion at the base edge of the engaging flap.

Inventors

  • 👤 Junichi Itsubo
  • 👤 Takashi Yazaki
  • 👤 Fumio Mori

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 15:06
CPC Classifications
B; B65; B65D; B65D41/00; B65D41/32; B65D41/34; B65D41/3423; B65D41/3428; B65D2401/00; B65D2401/15; B65D2401/30; B65D2401/35

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 247 words
A pilfer-proof plastic closure for a container equipped with a mouth-neck portion having an external thread formed on its peripheral surface and a holding jaw portion located below the external thread, said closure comprising a top panel wall and a cylindrical skirt wall extending downwardly from the peripheral edge of the top panel wall, said skirt wall having formed therein a circumferentially extending breakable line dividing the skirt wall into a main portion above the breakable line and a pilfer-proof bottom portion below it, said main portion having formed on its inner surface an internal thread to be engaged with the external thread on the mouth-neck portion of the container and said pilfer-proof bottom portion having formed on its inner surface a plurality of radially inwardly projecting engaging flaps at circumferentially spaced positions; each of said engaging flaps having a first portion extending from the inner surface of the pilfer-proof bottom portion tiltedly in a direction opposite to the direction of rotation of the closure at the time of mounting it on the mouth-neck portion of the container and a second portion bent with respect to the first portion and further extending from the end of the first portion, and the first portion forming an angle α smaller than 90 degrees and the second portion forming an angle β larger than the angle α, both with respect to the tangent of the inner surface of the pilfer-proof bottom portion at the base edge of the engaging flap.
Claim 2
Dependent Claim 247 words
A pilfer-proof plastic closure for a container equipped with a mouth-neck portion having an external thread formed on its peripheral surface and a holding jaw portion located below the external thread, said closure comprising a top panel wall and a cylindrical skirt wall extending downwardly from the peripheral edge of the top panel wall, said skirt wall having formed therein a circumferentially extending breakable line dividing the skirt wall into a main portion above the breakable line and a pilfer-proof bottom portion below it, said main portion having formed on its inner surface an internal thread to be engaged with the external thread on the mouth-neck portion of the container and said pilfer-proof bottom portion having formed on its inner surface a plurality of radially inwardly projecting engaging flaps at circumferentially spaced positions; each of said engaging flaps having a first portion extending from the inner surface of the pilfer-proof bottom portion tiltedly in a direction opposite to the direction of rotation of the closure at the time of mounting it on the mouth-neck portion of the container and a second portion bent with respect to the first portion and further extending from the end of the first portion, and the first portion forming an angle α smaller than 90 degrees and the second portion forming an angle β larger than the angle α, both with respect to the tangent of the inner surface of the pilfer-proof bottom portion at the base edge of the engaging flap.
Claim 3
Dependent Claim 14 words
The closure of claim 1 wherein the angle α is 30 to 85 degrees.
Claim 4
Dependent Claim 14 words
The closure of claim 2 wherein the angle α is 50 to 80 degrees.
Claim 5
Dependent Claim 14 words
The closure of claim 1 wherein the angle β is 60 to 180 degrees.
Claim 6
Dependent Claim 14 words
The closure of claim 4 wherein the angle β is 90 to 160 degrees.

References Cited (Backward Citations)

US4418828A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-06-03 1988-12-03 1989-06-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-06-03 1992-12-03 1993-06-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-06-03 1996-12-03 1997-06-04 $7700.00 Window Closed / Lapsed

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