US4069003A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Injection molding apparatus
Assignee: DINAMODE CORP
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Filing: 1975-04-21
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Granted: 1978-01-17
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Expires: 1995-04-21
Abstract
Abstract A method and apparatus for the injection molding of plastics wherein the sprue bushing is provided with a plurality of grooves in its bore as contrasted with the conventional sprue bushings having smooth bores. The sprue formed is complementarily ribbed and these irregular surfaces speed cooling of the sprue and facilitate manual handling thereof.
Inventors
- 👤 Ronald L. Cecchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:50
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/26; B29C45/27; B29C45/2701; Y; Y10; Y10S; Y10S425/00; Y10S425/227
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
182 words
A sprue bushing for use with a mold in plastics injection molding operations wherein a sprue is integrally formed at each injection with the part being molded, said sprue bushing comprising: a generally cylindrical body member having an inner end, an outer injection end, and a longitudinal frusto-conical bore extending therethrough between said ends, said bore being concentric with the central longitudinal axis of the body member and tapering outwardly toward said inner end, and a plurality of straight elongate grooves formed in the wall of said bore extending longitudinally over at least 50% of the length thereof and converging toward said injection end, adjacent sides of adjacent grooves converging to apices at a first radial distance from the central longitudinal axis of the bore, and sides of each groove converging to points at a radial distance from the central longitudinal axis substantially greater than said first radial distance, said grooves thereby increasing the surface area of the bore to enhance heat transfer and producing a sprue which is readily released from the bushing with simple longitudinal and non-rotational relative movement therebetween.
Claim 2
Dependent Claim
182 words
A sprue bushing for use with a mold in plastics injection molding operations wherein a sprue is integrally formed at each injection with the part being molded, said sprue bushing comprising: a generally cylindrical body member having an inner end, an outer injection end, and a longitudinal frusto-conical bore extending therethrough between said ends, said bore being concentric with the central longitudinal axis of the body member and tapering outwardly toward said inner end, and a plurality of straight elongate grooves formed in the wall of said bore extending longitudinally over at least 50% of the length thereof and converging toward said injection end, adjacent sides of adjacent grooves converging to apices at a first radial distance from the central longitudinal axis of the bore, and sides of each groove converging to points at a radial distance from the central longitudinal axis substantially greater than said first radial distance, said grooves thereby increasing the surface area of the bore to enhance heat transfer and producing a sprue which is readily released from the bushing with simple longitudinal and non-rotational relative movement therebetween.
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) | 1981-01-16 | 1981-07-18 | 1982-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-16 | 1985-07-18 | 1986-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-16 | 1989-07-18 | 1990-01-17 | $7700.00 | Window Closed / Lapsed |