Patent EP0133420A2 successfully refreshed from Google Patents.
US4034036A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Parison control in longitudinal stretch
Assignee: BM Inc A CORP OF NJ
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Filing: 1975-10-31
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Granted: 1977-07-05
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Expires: 1995-10-31
Abstract
Abstract An injection molded parison is positioned in a mold cavity having a high length to diameter ratio and being provided with means along the length of the cavity to selectively and alternatively exert positive pressure as an air cushion, or negative pressure as a vacuum, on portions of the parison as the parison is expanded through the length of the cavity. The thickness of the expanding parison is thus controlled so that in subsequent expansion in the blow mold, the finished hollow article will have the desired wall thickness.
Inventors
- 👤 John Jerome Farrell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:08
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/08; B29C49/16; B29C33/00; B29C33/38; B29C33/3814; B29C49/42; B29C49/58; B29C49/48; B29C2049/4879; B29C2049/4881; B29C49/70; B29C2049/701; B29C2049/702; B29C2791/00; B29C2791/004; B29C2791/006; B29C2791/007; B29C2949/00; B29C2949/07; B29C2949/0715; B29C49/02; B29C49/06
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
90 words
A method for controlling the thickness of a parison comprising: providing a fluid on the inside of the parison to expand the parison in the longitudinal direction while exerting a vacuum on a first portion of the outside of the parison to hold that first portion from further longitudinal extension and exerting a fluid cushion on another portion of the outside of the parison to permit longitudinal extension of that another portion so as to control the thickness of the parison as it undergoes longitudinal expansion prior to blow molding.
Claim 2
Independent Claim
90 words
A method for controlling the thickness of a parison comprising: providing a fluid on the inside of the parison to expand the parison in the longitudinal direction while exerting a vacuum on a first portion of the outside of the parison to hold that first portion from further longitudinal extension and exerting a fluid cushion on another portion of the outside of the parison to permit longitudinal extension of that another portion so as to control the thickness of the parison as it undergoes longitudinal expansion prior to blow molding.
Claim 3
Dependent Claim
36 words
The method of claim 1, wherein the longitudinal expansion of the parison, the vacuum holding of the one portion of the parison, and the fluid cushioning of the other portion of the parison are performed simultaneously.
Claim 4
Dependent Claim
17 words
The method of claim 2, wherein the fluid cushion pressure is not greater than the expansion pressure.
Claim 5
Dependent Claim
36 words
The method of claim 2, further comprising the first step of conditioning the parison to its orientation temperature so that the parison is oriented in the longitudinal axial direction for subsequent radial orientation in blow molding.
Claim 6
Dependent Claim
42 words
The method of claim 4, comprising the first step of providing the parison in a mold wherein the internal cavity of said mold is shaped so that the parison will be substantially longitudinally axially oriented without substantial radial orientation during longitudinal expansion.
Claim 7
Dependent Claim
36 words
The method of claim 1, wherein said parison is tubular and wherein said vacuum is effected on a cylindrical portion of the parison and said fluid cushion is effected on another cylindrical portion of the parison.
Claim 8
Dependent Claim
17 words
The method of claim 6, wherein said vacuum and fluid cushion are effected on adjacent cylindrical portions.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-04 | 1981-01-03 | 1981-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-04 | 1985-01-03 | 1985-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-04 | 1989-01-03 | 1989-07-05 | $7700.00 | Window Closed / Lapsed |