Patent US3719441A successfully refreshed from Google Patents.
US3719441A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for molding articles
Assignee: Honeywell International Inc
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Filing: 1970-06-22
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Granted: 1973-03-06
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Expires: 1990-06-22
Abstract
Abstract This disclosure is directed to a method of for injection molding. Premature foaming and setting of foamable molding materials is prevented by accomplishing the injection of the molding material into a preheated mold cavity having a gaseous substance therein at a pressure in excess of that required to prevent foaming of the molding material. Planned wastage of molding material is minimized by providing pistons in the runners which carry the molding materials to the mold, which pistons force excess molding material away from the mold so as to recompress and recover the material, thereby to be used in the next subsequent molding cycle.
Inventors
- 👤 A Spaak
- 👤 C Weir
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:07
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/02; B29C44/10; B29C44/105; B29C45/00; B29C45/17; B29C45/26; B29C45/46
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
98 words
An apparatus for the injection molding of a molding material comprising: a mold having a mold cavity therein; a chamber for the preparation of molding material prior to injection; a passage between said cavity and said chamber for accommodating the passage of molding material therethrough; means for injecting molding material from said chamber into said mold cavity; and means for forcing excess molding away from said molding cavity toward said chamber after said molding cavity has been filled whereby to compress and comingle said excess molding material with material to be used with a next subsequent molding cycle.
Claim 2
Independent Claim
98 words
An apparatus for the injection molding of a molding material comprising: a mold having a mold cavity therein; a chamber for the preparation of molding material prior to injection; a passage between said cavity and said chamber for accommodating the passage of molding material therethrough; means for injecting molding material from said chamber into said mold cavity; and means for forcing excess molding away from said molding cavity toward said chamber after said molding cavity has been filled whereby to compress and comingle said excess molding material with material to be used with a next subsequent molding cycle.
Claim 3
Independent Claim
98 words
An apparatus for the injection molding of a molding material comprising: a mold having a mold cavity therein; a chamber for the preparation of molding material prior to injection; a passage between said cavity and said chamber for accommodating the passage of molding material therethrough; means for injecting molding material from said chamber into said mold cavity; and means for forcing excess molding away from said molding cavity toward said chamber after said molding cavity has been filled whereby to compress and comingle said excess molding material with material to be used with a next subsequent molding cycle.
Claim 4
Independent Claim
98 words
An apparatus for the injection molding of a molding material comprising: a mold having a mold cavity therein; a chamber for the preparation of molding material prior to injection; a passage between said cavity and said chamber for accommodating the passage of molding material therethrough; means for injecting molding material from said chamber into said mold cavity; and means for forcing excess molding away from said molding cavity toward said chamber after said molding cavity has been filled whereby to compress and comingle said excess molding material with material to be used with a next subsequent molding cycle.
Claim 5
Dependent Claim
41 words
An apparatus as claimed in claim 1 and further including: means for introducing a pressurized gaseous substance into said mold cavity prior to the injection of said foamable molding material so as to prevent foaming of said molding material during injection.
Claim 6
Dependent Claim
69 words
An apparatus as claimed in claim 2 and further including: means for exhausting said pressurized gaseous substance from said mold cavity during injection of said molding material so as to maintain the pressure of said gaseous substance in said mold cavity at a level in excess of the pressure at which said foamable molding material will foam, and less than the pressure at which said molding material is injected.
Claim 7
Dependent Claim
18 words
The apparatus as claimed in claim 3 wherein: said means for exhausting is a presettable pressure relief valve.
Claim 8
Dependent Claim
34 words
An apparatus as claimed in claim 1 and further including: heating and cooling means for controlling the temperature of said mold before, during and after the injection of molding material into said mold cavity.
Claim 9
Dependent Claim
50 words
An apparatus for injection molding as claimed in claim 5, wherein said means for controlling the temperature of said mold comprises; heating means mounted in said mold, and a set of passages formed in said mold, said set of passages for accommodating the circulation of a relatively cold fluid therethrough.
Claim 10
Dependent Claim
41 words
An apparatus as claimed in claim 6 wherein: said mold comprises a retractable mold section and a stationary mold section; and each of said retractable mold section and said stationary mold section have heating means and fluid circulating passages disposed therein.
Claim 11
Independent Claim
30 words
The apparatus as claimed 1 wherein: said passages comprise an injection passage, a runner passage and a sprue passage; and said means for forcing is mounted in said runner passage
Claim 12
Dependent Claim
23 words
The apparatus as claimed in claim 8 wherein: said means for forcing comprising at least one piston reciprocably mounted in said runner passage.
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) | 1976-03-05 | 1976-09-04 | 1977-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-05 | 1980-09-04 | 1981-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-05 | 1984-09-04 | 1985-03-06 | $7700.00 | Window Closed / Lapsed |