US3790312A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pumps for liquids
Assignee: Individual
•
Filing: 1972-07-24
•
Granted: 1974-02-05
•
Expires: 1992-07-24
Abstract
Abstract A pump for a liquid comprises a housing a first chamber in the housing, an inlet and an outlet for said front chamber a second chamber in the housing sealingly separated from the first chamber, an electric motor in the second chamber, a third chamber between the first and second chambers, an outlet from said third chamber, a main impeller in the first chamber, an anusiliary impeller in the third chamber to urge any fluid leaking from said first and second chamber to the outlet.
Inventors
- 👤 H Bottoms
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:45
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/08; F04D29/10; F04D29/12; F04D29/126; F04D29/128; F04D13/00; F04D13/02; F04D13/06; F04D13/08; F04D13/086; F04D9/00; F04D9/04
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
115 words
A pump for a liquid comprising a housing, a first chamber within the housing, an inlet and an outlet for said first chamber a second chamber within the housing sealingly separated from said first chamber, an electric motor within said second chamber, a third chamber within the housing between said first and second chambers and sealingly separated therefrom, an outlet from said third chamber, a first impeller in said first chamber drivable by the motor to urge liquid from the inlet to the outlet of said first chamber, and a second impeller in the third chamber drivable by the motor to urge fluid leaking from said first and second chambers to the third chamber outlet.
Claim 2
Dependent Claim
115 words
A pump for a liquid comprising a housing, a first chamber within the housing, an inlet and an outlet for said first chamber a second chamber within the housing sealingly separated from said first chamber, an electric motor within said second chamber, a third chamber within the housing between said first and second chambers and sealingly separated therefrom, an outlet from said third chamber, a first impeller in said first chamber drivable by the motor to urge liquid from the inlet to the outlet of said first chamber, and a second impeller in the third chamber drivable by the motor to urge fluid leaking from said first and second chambers to the third chamber outlet.
Claim 3
Dependent Claim
62 words
A pump as claimed in claim 1 in which there is provided a labyrinth seal separating the second chamber from the third chamber, second impeller causing, in use, a substantially constant flow of air from said second chamber to said third chamber through said labyrinth seal so as to prevent any liquid which enters said third chamber passing through said labyrinth seal.
Claim 4
Dependent Claim
49 words
A pump as claimed in claim 2 including a sealed bearing supporting the motor shaft adjacent said labyrinth seal, said housing being formed with at least one by-pass passage adjacent said bearing through which air passes towards said labyrinth seal whereby no pressure drop is created across said bearing.
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) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |