Patent US3895900A successfully refreshed from Google Patents.
US3895900A
Expired / Lapsed
US
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Plastics extrusion die head improvement
Assignee: Standard Oil Co
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Filing: 1974-02-21
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Granted: 1975-07-22
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Expires: 1994-02-21
Abstract
Abstract An improved plastic extrusion blow molding die head is described which permits the formation of extruded parisons having controlled wall thickness by partial restriction of the entering flow of the molten plastic material into the die head.
Inventors
- 👤 Albert J Herold
- 👤 Paul E Koch
- 👤 Richard C Adams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:47
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/30; B29C48/32; B29C48/34; B29C48/03; B29C48/09; B29C48/10
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
120 words
In an extrusion blow molding die head comprising a die body equipped with a removable die bushing, said die body having an internally, somewhat generally conicAl hollow area fitted with a stationary tubular cone through which extends a movable internal shaft having a core pin which extends into and near the end of the opening in the die bushing said die body also having a fixed gap and a channel for plastic flow near an insert ring located at the top of said tubular cone, the improvement comprising an obstruction located at the bottom of the insert ring and extending about half the circumference of the tubular cone in the area where the plastic enters the channel for plastic flow.
Claim 2
Dependent Claim
120 words
In an extrusion blow molding die head comprising a die body equipped with a removable die bushing, said die body having an internally, somewhat generally conicAl hollow area fitted with a stationary tubular cone through which extends a movable internal shaft having a core pin which extends into and near the end of the opening in the die bushing said die body also having a fixed gap and a channel for plastic flow near an insert ring located at the top of said tubular cone, the improvement comprising an obstruction located at the bottom of the insert ring and extending about half the circumference of the tubular cone in the area where the plastic enters the channel for plastic flow.
Claim 3
Dependent Claim
16 words
The apparatus of claim 1 wherein the obstruction is in the form of a welded bead.
References Cited (Backward Citations)
US3144682A
Cited
US3390430A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-21 | 1979-01-20 | 1979-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-21 | 1983-01-20 | 1983-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-21 | 1987-01-20 | 1987-07-22 | $7700.00 | Window Closed / Lapsed |