US4490315A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods of moulding of plastics articles
Assignee: Nortel Networks Ltd
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Filing: 1983-10-31
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Granted: 1984-12-25
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Expires: 2003-10-31
Abstract
Abstract A method of moulding by low pressure moulding wherein a passage from the mould cavity is bridged by the molten material during filling and in which the moulding pressure is too low to cause the material to flow down the passage. After the mould is completely filled, the pressure increases to cause penetration of the molten material along the passage to a switch operating position to operate a switch to stop further flow of material into the mould.
Inventors
- 👤 Leonard J. Charlebois
- 👤 Fred A. Huszarik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:28
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/14; B29C45/17; B29C45/76; B29C45/7613; B29C70/00; B29C70/68; B29C70/72
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
153 words
A method of moulding an article in the form of an encapsulation around an object which is deformable or crushable under a certain compressive load, comprising causing molten plastics material to flow at a low pressure into a mould cavity containing the object and, during filling, causing the material to extend across and bridge an open passage extending from the cavity and permitting the commencement of formation of a skin on the material bridging the passage, said skin being thinner than skin contacting surfaces of the mould, and filling the cavity to effect an increase in pressure in the molten material, which pressure is below that required to deform or crush the object but is sufficient to cause rupture of said thinner skin and to force a flow of the molten material along the passage to a switch operating location and operate a switch to cease futher flow of material into the mould.
Claim 2
Independent Claim
153 words
A method of moulding an article in the form of an encapsulation around an object which is deformable or crushable under a certain compressive load, comprising causing molten plastics material to flow at a low pressure into a mould cavity containing the object and, during filling, causing the material to extend across and bridge an open passage extending from the cavity and permitting the commencement of formation of a skin on the material bridging the passage, said skin being thinner than skin contacting surfaces of the mould, and filling the cavity to effect an increase in pressure in the molten material, which pressure is below that required to deform or crush the object but is sufficient to cause rupture of said thinner skin and to force a flow of the molten material along the passage to a switch operating location and operate a switch to cease futher flow of material into the mould.
References Cited (Backward Citations)
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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) | 1987-12-25 | 1988-06-25 | 1988-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-25 | 1992-06-25 | 1992-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-25 | 1996-06-25 | 1996-12-25 | $7700.00 | Window Closed / Lapsed |