EP0029639A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Plastics container, method of forming same, a preform for use in forming the container and a mold unit for forming the preform
Assignee: Continental Group Inc
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Filing: 1980-06-09
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Granted: —
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Expires: 2000-06-09
Abstract
Abstract This disclosure relates to an improvement in the strength of a bottle bottom of the champagne type by the addition of ribs (75) internally of the preform (44) when the preform is axially stretched prior to the blowing thereof within the blow mold. Most particularly, by adding internal ribs (75) to the interior surface of the bottom defining portion (49) of the preform (44), the preform has the bottom forming portion unduly strengthened against shrinkage in wall thickness when the preform is axially lengthened through the use of a stretch rod. The net result is that the stretching of the preform (44) and the thinning of the wall is held to a minimum in the bottom forming portion (49) of the preform and is transferred primarily to the body forming (78) of the preform where lesser wall thickness does not unduly detract from the strength of the bottle.
Inventors
- 👤 Suppayan M. Krishnakumar
- 👤 John F.E. Pocock
- 👤 Kenneth F.M. Friendship
- 👤 Gautam K. Mahajan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 12:07
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/08; B29C49/10; B29C49/12; B65; B65D; B65D1/00; B65D1/02; B65D1/0223; B65D1/0261; B65D1/0276; B29C45/00; B29C45/17; B29C45/26; B29C49/20; B29C49/02; B29C2049/023; B29C2949/00; B29C2949/07; B29C2949/0715; B29C2949/072; B29C2949/0725; B29C2949/073; B29C2949/0731; B29C2949/0733; B29C2949/074; B29C2949/0747; B29C2949/076; B29C2949/0768; B29C2949/077; B29C2949/0772; B29C2949/0773; B29C2949/0777; B29C2949/078; B29C2949/0861; B29C2949/0872; B29C2949/20; B29C2949/22; B29C2949/24; B29C2949/26; B29C2949/28; B29C49/06; B29K; B29K2105/00; B29K2105/25; B29K2105/253
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
59 words
A preform for use in the blow molding of a plastic material bottle having an internal reinforcing rib arrangement, characterised in that said preform is formed of a plastic material and includes a tubular lower portion terminating in a closed end, and an arrangement of longitudinally extending ribs integrally formed on the inner surface of said tubular lower portion.
Claim 2
Dependent Claim
59 words
A preform for use in the blow molding of a plastic material bottle having an internal reinforcing rib arrangement, characterised in that said preform is formed of a plastic material and includes a tubular lower portion terminating in a closed end, and an arrangement of longitudinally extending ribs integrally formed on the inner surface of said tubular lower portion.
Claim 3
Dependent Claim
17 words
A preform according to claim 1 wherein said ribs extend into and terminate in said closed end.
Claim 4
Dependent Claim
37 words
A preform according to claim 1 or 2 wherein said closed end is generally'hemispherical and said ribs extend into and terminate in said closed end in a natural transition due to the curvature of said closed end.
Claim 5
Dependent Claim
44 words
A preform according to claim 1, 2 or 3 wherein said closed end and a preselected part only of said tubular lower portion define means for forming a bottle bottom portion, and said ribs terminate remote from said closed end within said preselected part.
Claim 6
Dependent Claim
34 words
A preform according to any of claims 1 to 4 wherein each of said ribs is part circular in cross section and has remote ends rounded in both a longitudinal and a transverse sense.
Claim 7
Dependent Claim
32 words
A preform according to any of claims 1 to 5 wherein said closed end is generally hemispherical and said ribs are dis- .posed substantially entirely within the confines of said closed end..
Claim 8
Dependent Claim
28 words
A preform according to any of claims to 6 wherein said ribs are of a reduced thickness at their line of juncture with the remainder of the preform.
Claim 9
Dependent Claim
28 words
A preform according to any of claims 1 to 7 wherein said ribs have lower end portions extending generally radially inwardly adjacent their juncture with said closed end,
Claim 10
Dependent Claim
75 words
9 . A mold unit for injection molding a plastic material preform for a blow molded bottle wherein the preform has an internal arrangement of longitudinally extending ribs, characterised in that the mold unit has a moulded core member having a lower portion terminating in an end portion, and an arrangement of longitudinally extending rib defining grooves of limited longitudinal extent formed in said core member lower portion, said grooves having longitudinally open lower ends.
Claim 11
Dependent Claim
75 words
9 . A mold unit for injection molding a plastic material preform for a blow molded bottle wherein the preform has an internal arrangement of longitudinally extending ribs, characterised in that the mold unit has a moulded core member having a lower portion terminating in an end portion, and an arrangement of longitudinally extending rib defining grooves of limited longitudinal extent formed in said core member lower portion, said grooves having longitudinally open lower ends.
Claim 12
Dependent Claim
35 words
A mold core member according to claim 10 wherein said end portion is generally hemispherical and said grooves terminate within said end portion in a natural transition due to the curvature of said end portion.
Claim 13
Dependent Claim
32 words
11 . A mold core member according to claim 10 or 11 wherein said core member has a longitudinal axis and said grooves have radially innermost surfuces disposed parallel to said axis.
Claim 14
Dependent Claim
50 words
A mold unit according to claim 9, 10 or 11 wherein said mold unit also includes a cavity defining mold member for receiving and cooperating with said mold core member, and said cavity being smooth in that portion thereof aligned with said mold core member lower portion and end portion.
Claim 15
Independent Claim
119 words
A method oi forming a plastic material bottle having a bottom provided with radially extending internal stiffening ribs, characterised in that said method comprises the steps of providing an injection mold including a cavity defining mold member and a core member in said cavity with said core member having an arrangement of rib defining grooves in a lower portion thereof; injection molding a plastic material tubular preform in said cavity around said core member with said preform having a bottle bottom defining lower portion with internal longitudinally extending ribs in accordance with said core member grooves; and then blow molding said preform in a blow mold to define a bottle having a bottom with radially extending internal stiffening ribs.
Claim 16
Independent Claim
119 words
A method oi forming a plastic material bottle having a bottom provided with radially extending internal stiffening ribs, characterised in that said method comprises the steps of providing an injection mold including a cavity defining mold member and a core member in said cavity with said core member having an arrangement of rib defining grooves in a lower portion thereof; injection molding a plastic material tubular preform in said cavity around said core member with said preform having a bottle bottom defining lower portion with internal longitudinally extending ribs in accordance with said core member grooves; and then blow molding said preform in a blow mold to define a bottle having a bottom with radially extending internal stiffening ribs.
Claim 17
Independent Claim
129 words
A method of increasing the wall thickness of a bottom structure of a blown plastic material container, characterised in that said method comprises the steps of forming a preform including a generally hemispherical bottom portion and internal ribs extending axially from said bottom portion in the area of the preform which corresponds to the bottom structure of the container, inserting the preform within-a blow mold for the container, holding an upper end of said preform against movement and moving the preform bottom portion axially to axially stretch said preform with said stretching primarily occurring in an intermediate portion of said preform as opposed to occurring in the bottom portion of said preform, and thereafter blow molding said preform to form a container having a thicker than normal bottom structure.
Claim 18
Independent Claim
129 words
A method of increasing the wall thickness of a bottom structure of a blown plastic material container, characterised in that said method comprises the steps of forming a preform including a generally hemispherical bottom portion and internal ribs extending axially from said bottom portion in the area of the preform which corresponds to the bottom structure of the container, inserting the preform within-a blow mold for the container, holding an upper end of said preform against movement and moving the preform bottom portion axially to axially stretch said preform with said stretching primarily occurring in an intermediate portion of said preform as opposed to occurring in the bottom portion of said preform, and thereafter blow molding said preform to form a container having a thicker than normal bottom structure.
Claim 19
Dependent Claim
31 words
1 5. The method of claim 14 wherein the increase in weight of said container bottom structure is of the order of 8 times the added weight of the internal ribs.
Claim 20
Dependent Claim
104 words
A bottom structure of a thermoplastic bottle, said bottom structure comprising an outer bottom portion having a radially inner lower edge, an inner generally radially and axially concaved bottom portion disposed within said bottom portion in recessed relation and having a radially outer lower edge, and an annular arcuate cross-sectional intermediate bottom portion joining the lower edges of said outer bottom portion and said inner bottom portion; characterised in that there are provided means reinforcing said intermediate bottom portion against deflection, said means being in the form of a plurality of circumferentially spaced radiating ribs extending at least generally across said intermediate bottom portion.
Claim 21
Dependent Claim
104 words
A bottom structure of a thermoplastic bottle, said bottom structure comprising an outer bottom portion having a radially inner lower edge, an inner generally radially and axially concaved bottom portion disposed within said bottom portion in recessed relation and having a radially outer lower edge, and an annular arcuate cross-sectional intermediate bottom portion joining the lower edges of said outer bottom portion and said inner bottom portion; characterised in that there are provided means reinforcing said intermediate bottom portion against deflection, said means being in the form of a plurality of circumferentially spaced radiating ribs extending at least generally across said intermediate bottom portion.
Claim 22
Dependent Claim
27 words
The bottom structure of claim 16 wherein each of said ribs has end portions terminating-respective- l y in said outer bottom portion and said inner bottom portion.
Claim 23
Dependent Claim
35 words
1 8. The bottom structure of claim 1 6 wherein each of said ribs has end portions terminating respectively in said outer bottom portion and said inner bottom portion immediately adjacent said intermediate bottom portion.
Claim 24
Dependent Claim
41 words
19 . The bottom structure of claim 16 wherein each of said ribs has an outer end portion terminating in said outer bottom portion closely adjacent said intermediate bottom portion and an inner end portion terminating in said inner bottom portion.
Claim 25
Dependent Claim
48 words
2 0 . The bottom structure of claim 16 wherein each of said ribs has an outer end portion terminating in said outer bottom portion closely adjacent said intermediate bottom portion and an inner end portion terminating in said inner bottom portion remote from said intermediate bottom portion.
Claim 26
Dependent Claim
27 words
The bottom structure of claim 17 wherein said inner bottom portion includes an uppermost thickened dome, and said inner ends of said ribs terminate adjacent said dome.
Claim 27
Dependent Claim
31 words
The bottom structure of claim 17 wherein said inner bottom portion includes an uppermost thickened dome, and said inner ends of said ribs terminate in said dome in spaced adjacent relation.
Claim 28
Dependent Claim
18 words
The bottom structure of any of claims 16 to 22wherein each rib is generally semicircular in cross section.
Claim 29
Dependent Claim
30 words
The bottom structure of any of claims 16 to 19 wherein each rib is generally teardrop shape in plan and has a rounded nose terminating in said inner bottom portion.
Claim 30
Dependent Claim
19 words
The bottom structure of any of claims 16 to 23 wherein each rib is generally elongated oval in plan.
Claim 31
Dependent Claim
33 words
The bottom structure of any of claims 16 to 23 wherein each rib is generally rectangular in cross section and forms flow guiding means for a liquid when said bottle is being filled.
Claim 32
Dependent Claim
30 words
The bottom structure of any of claims 16 to 26 wherein said outer bottom portion is a truncated hemispherical sector merging at the upper end thereof into a cylindrical body.
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