US3771931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for molding plastic articles
Assignee: KEER GLASS MANUF CORP
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Filing: 1970-08-13
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Granted: 1973-11-13
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Expires: 1990-08-13
Abstract
Abstract A method and apparatus for blow molding of hollow plastic articles such as bottles and containers from continuously extruded tubular parison by employing a cooling system acting upon the parison between the extruder and the molds to control the temperature of the parison as it enters the mold to provide an improved product having walls of relatively uniform thickness.
Inventors
- 👤 R Fischer
- 👤 D Straub
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:23
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/42; B29C49/64; B29C49/6409; B29C49/6436; B29C49/6445; B29C48/00; B29C48/03; B29C48/09; B29C48/12; B29C48/13; B29C48/25; B29C48/88; B29C48/911; B29C48/9115; B29C49/02; B29C49/04; B29C49/04102; B29C49/0411; B29C49/04114; B29C35/00; B29C35/02; B29C35/04; B29C35/16; B29C48/001; B29C48/0017; B29C48/10
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
127 words
In an apparatus for blow molding hollow plastic articles, the combination of an extruder for extruding a tubular parison, a series of moving blow molds adapted to sever lengths of said tubular parison and to blow said lengths into said plastic articles, cooling means positioned adjacent said tubular parison between said extruder and the point of contact of the parison with said molds and adapted to direct cooling fluid onto the surface of said parison as it exits from said extruder, and means for regulating the application of the cooling fluid by said cooling means onto the surface of said parison, said regulating means being operable to periodically vary the flow of cooling fluid to limit parison attenuation and to attain uniform walls in the finished article.
Claim 2
Dependent Claim
127 words
In an apparatus for blow molding hollow plastic articles, the combination of an extruder for extruding a tubular parison, a series of moving blow molds adapted to sever lengths of said tubular parison and to blow said lengths into said plastic articles, cooling means positioned adjacent said tubular parison between said extruder and the point of contact of the parison with said molds and adapted to direct cooling fluid onto the surface of said parison as it exits from said extruder, and means for regulating the application of the cooling fluid by said cooling means onto the surface of said parison, said regulating means being operable to periodically vary the flow of cooling fluid to limit parison attenuation and to attain uniform walls in the finished article.
Claim 3
Dependent Claim
72 words
An apparatus as set forth in claim 1 wherein said cooling means is stationary and said parison moves from said extruder through said cooling means to said molds, and wherein said regulating means is operable to periodically vary the flow of cooling fluid in predetermined cycles corresponding to each mold length to selectively cool different portions of said parison whereby the wall thickness of the hollow plastic article is controlled during blowing.
Claim 4
Dependent Claim
83 words
An apparatus as set forth in claim 2 wherein said predetermined cycles of cooling fluid flow vary from a minimum flow against the portion of the parison to be engaged by the bottom of each mold to a maximum at the portion of the parison to be engaged by the top of the mold to inhibit parison attenuation due to gravity and wherein said regulating means further comprises a servomechanism and valve synchronized with the movement of said mOlds to control said cycles.
Claim 5
Dependent Claim
45 words
An apparatus as set forth in claim 2 wherein said predetermined cycles of cooling fluid flow vary to provide maximum cooling in areas of the parison to be subjected to greatest plastic flow in the mold thereby promoting uniform wall thickness throughout the finished article.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-12 | 1977-05-14 | 1977-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-12 | 1981-05-14 | 1981-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-12 | 1985-05-14 | 1985-11-13 | $7700.00 | Window Closed / Lapsed |