Patent US3746481A successfully refreshed from Google Patents.
US3746481A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gear pump for viscous thermoplastic melts
Assignee: Oerlikon Barmag AG
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Filing: 1970-08-06
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Granted: 1973-07-17
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Expires: 1990-08-06
Abstract
Abstract A gear pump having two rotatable intermeshed gears mounted in a hollow cavity of the pump casing for transporting and discharging a viscous thermoplastic melt, the hollow cavity being enlarged at the inlet side of the pump casing to provide an elongated arcuate wedge-shaped filling chamber extending from the inlet outwardly around each gear to converge onto the gear periphery in the circumferential direction of the transported melt.
Inventors
- 👤 H Schippers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:24
CPC Classifications
F; F04; F04C; F04C15/00; F04C15/06; F04C15/062; F04C13/00; F04C13/001; F04C2/00; F04C2/08; F04C2/082; F04C2/086
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
28 words
A gear pump as claimed in claim 1 wherein the length of said wedge-shaped filling chamber is about 6 to 8 times the height of a gear tooth.
Claim 2
Dependent Claim
26 words
A gear pump as claimed in claim 1 wherein the intersecting edge of the inlet wall with the cavity wall facing the gear periphery is rounded.
Claim 3
Dependent Claim
41 words
A gear pump as claimed in claim 3 wherein the radius of said rounded edge between the inlet wall and the cavity wall facing the gear periphery is equal to at least about one times the height of a gear tooth.
Claim 4
Dependent Claim
20 words
A gear pump as claimed in claim 1 wherein heating means are included in the walls of the pump casing.
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) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |