Patent US3961113A successfully refreshed from Google Patents.
US3961113A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermoplastic preform and heated mandrel constructions
Assignee: Dart Container Corp
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Filing: 1975-03-03
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Granted: 1976-06-01
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Expires: 1995-03-03
Abstract
Abstract A preform of generally elongate conical configuration from the open end thereof to the opposite smaller end closed, as by a rounded tip portion, with a smooth interior surface throughout the major portion thereof from the tip portion to an area adjacent the open end; and the telescopic association of the preform with a heated complementally shaped smooth surfaced mandrel; the area of the preform adjacent the open end thereof having internal circumferentially spaced surface portions providing passages therealong for vacuum withdrawal of air to conform the inner surface of the major portion of the preform in intimate thermal contact with the mandrel prior to conformation of the passaged area of the preform with the adjacent surface of the mandrel under heating of the preform to molding temperature and subsequent association of the mandrel and preform in a female mold for re-shaping the preform under applied differential pressure.
Inventors
- 👤 Leslie Stephan Marco
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:31
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/42; B29C49/58; B29C2949/00; B29C2949/07; B29C2949/0715; B29C2949/072; B29C2949/0722; B29C2949/073; B29C2949/0733; B29C2949/074; B29C2949/0744; B29C2949/076; B29C2949/0761; B29C2949/0762; B29C2949/0768; B29C2949/077; B29C2949/20; B29C2949/22; B29C2949/24; B29C2949/26; B29C2949/28; B29C49/02; B29C49/06; Y; Y10; Y10S; Y10S264/00; Y10S264/66; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/1397; Y10T428/24; Y10T428/24479; Y10T428/2457
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
173 words
A plastic preform for application to a complementally shaped smooth surfaced heated mandrel of the type used in plastic molding machines for reshaping the preform under heat and applied differential pressure; and comprising a body portion of generally conical configuration from an open upper end to a closed smaller end and with a major smooth interior surface from the closed end to an area adjacent the open end, said area having internal spaced surface portions providing passages therealong for upward withdrawal of air from between the mandrel surface and the smooth interior surface of the preform body portion for uniform conformation of the smooth interior surface of the preform to the mandrel surface, and said preform body portion having an internal surface portion around the open end and close to the passaged area for contacting an adjacent remnant surface of the mandrel with permissive relative sliding movement therebetween under continued application of heat and differential pressure without reactive tendency for the major portion of the body portion to separate from the mandrel surface.
Claim 2
Dependent Claim
173 words
A plastic preform for application to a complementally shaped smooth surfaced heated mandrel of the type used in plastic molding machines for reshaping the preform under heat and applied differential pressure; and comprising a body portion of generally conical configuration from an open upper end to a closed smaller end and with a major smooth interior surface from the closed end to an area adjacent the open end, said area having internal spaced surface portions providing passages therealong for upward withdrawal of air from between the mandrel surface and the smooth interior surface of the preform body portion for uniform conformation of the smooth interior surface of the preform to the mandrel surface, and said preform body portion having an internal surface portion around the open end and close to the passaged area for contacting an adjacent remnant surface of the mandrel with permissive relative sliding movement therebetween under continued application of heat and differential pressure without reactive tendency for the major portion of the body portion to separate from the mandrel surface.
Claim 3
Dependent Claim
30 words
A preform as claimed in claim 1, wherein the passaged area of the preform is provided with spaced ribs to contact the adjacent mandrel surface and provide the passages therebetween.
Claim 4
Dependent Claim
30 words
A preform as claimed in claim 2, wherein the preform is provided with an outward inclined wall surface adjacent the bottom of the passaged area to present a stacking shoulder.
Claim 5
Dependent Claim
19 words
A preform as claimed in claim 3, wherein the ribs extend across the interior surface of the stacking shoulder.
Claim 6
Dependent Claim
29 words
A preform as claimed in claim 4, wherein the ribs extend substantially longitudinally of the preform axis across the passaged area and the interior surface of the stacking shoulder.
References Cited (Backward Citations)
US3341893A
Cited
US3398428A
Cited
US3420924A
Cited
US3770860A
Cited
US3719735A
Cited
US3696987A
Cited
US3882212A
Cited
US3787547A
Cited
US3892830A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-01 | 1979-12-01 | 1980-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-01 | 1983-12-01 | 1984-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-01 | 1987-12-01 | 1988-06-01 | $7700.00 | Window Closed / Lapsed |